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Sample records for char salvelinus alpinus

  1. Genetic analysis of sympatric char populations in western Alaska: Arctic char (Salvelinus alpinus) and Dolly Varden (Salvelinus malma) are not two sides of the same coin.

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    Taylor, E B; Lowery, E; Lilliestråle, A; Elz, A; Quinn, T P

    2008-11-01

    The North Pacific Ocean has been of great significance to understanding biogeography and speciation in temperate faunas, including for two species of char (Salmonidae: Salvelinus) whose evolutionary relationship has been controversial. We examined the morphology and genetics (microsatellite and mitochondrial DNA) of Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) in lake systems in western Alaska, the eastern and western Arctic, and south of the Alaskan Peninsula. Morphologically, each lake system contained two forms: one (Arctic char) largely confined to lake habitats and characterized by greater numbers of pyloric caeca, gill rakers, and shallower bodies, and another (Dolly Varden) predominated in adjacent stream habitats and was characterized by fewer pyloric caeca, gill rakers, and deeper bodies. MtDNA partial (550 bp) d-loop sequences of both taxa were interspersed with each other within a single 'Bering' clade and demographic inferences suggested historical gene flow from Dolly Varden to Arctic char had occurred. By contrast, the taxa were strongly differentiated in sympatry across nine microsatellite loci in both lakes. Our data show that the two taxa are highly genetically distinct in sympatry, supporting their status as valid biological species, despite occasional hybridization. The interaction between these species highlights the importance of the North Pacific, and Beringia in particular, as an evolutionary wellspring of biodiversity.

  2. Subcellular distribution of trace elements and liver histology of landlocked Arctic char (Salvelinus alpinus) sampled along a mercury contamination gradient.

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    Barst, Benjamin D; Rosabal, Maikel; Campbell, Peter G C; Muir, Derek G C; Wang, Xioawa; Köck, Günter; Drevnick, Paul E

    2016-05-01

    We sampled landlocked Arctic char (Salvelinus alpinus) from four lakes (Small, 9-Mile, North, Amituk) in the Canadian High Arctic that span a gradient of mercury contamination. Metals (Hg, Se, Tl, and Fe) were measured in char tissues to determine their relationships with health indices (relative condition factor and hepatosomatic index), stable nitrogen isotope ratios, and liver histology. A subcellular partitioning procedure was employed to determine how metals were distributed between potentially sensitive and detoxified compartments of Arctic char livers from a low- and high-mercury lake (Small Lake and Amituk Lake, respectively). Differences in health indices and metal concentrations among char populations were likely related to differences in feeding ecology. Concentrations of Hg, Se, and Tl were highest in the livers of Amituk char, whereas concentrations of Fe were highest in Small and 9-Mile char. At the subcellular level we found that although Amituk char had higher concentrations of Tl in whole liver than Small Lake char, they maintained a greater proportion of this metal in detoxified fractions, suggesting an attempt at detoxification. Mercury was found mainly in potentially sensitive fractions of both Small and Amituk Lake char, indicating that Arctic char are not effectively detoxifying this metal. Histological changes in char livers, mainly in the form of melano-macrophage aggregates and hepatic fibrosis, could be linked to the concentrations and subcellular distributions of essential or non-essential metals.

  3. Low levels of hybridization between sympatric Arctic char (Salvelinus alpinus) and Dolly Varden char (Salvelinus malma) highlights their genetic distinctiveness and ecological segregation.

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    May-McNally, Shannan L; Quinn, Thomas P; Taylor, Eric B

    2015-08-01

    Understanding the extent of interspecific hybridization and how ecological segregation may influence hybridization requires comprehensively sampling different habitats over a range of life history stages. Arctic char (Salvelinus alpinus) and Dolly Varden (S. malma) are recently diverged salmonid fishes that come into contact in several areas of the North Pacific where they occasionally hybridize. To better quantify the degree of hybridization and ecological segregation between these taxa, we sampled over 700 fish from multiple lake (littoral and profundal) and stream sites in two large, interconnected southwestern Alaskan lakes. Individuals were genotyped at 12 microsatellite markers, and genetic admixture (Q) values generated through Bayesian-based clustering revealed hybridization levels generally lower than reported in a previous study (Dolly Varden and Arctic char tended to make different use of stream habitats with the latter apparently abandoning streams for lake habitats after 2-3 years of age. Our results support the distinct biological species status of Dolly Varden and Arctic char and suggest that ecological segregation may be an important factor limiting opportunities for hybridization and/or the ecological performance of hybrid char.

  4. [Peculiarities of the parasitofauna of Atlantic salmon parr (Salmo salar L.), brown trout (Salmo truttae L.), and char (Salvelinus alpinus L.) in the Utsjoki River system (Northern Finland)].

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    Ieshko, E P; Barskaia, Iu Iu; Lebedeva, D I; Novokhatskaia, O V; Kaukoranta, M; Niemela, E

    2011-01-01

    Data on the parasite diversity in Salmonidae fish parr from different parts of the Utsjoki River obtained during 1993-1995 and 2006-2007 are presented. Three fish species, Salmo salar L., S. truttae L., and Salvelinus alpinus L., were examined on the presence of helminthes. Twenty species of salmon parasites were found, the majority of which are the parasites with complicated life cycles. Infusorians C apriniana piscium, myxosporidia Chloromyxum januaricus and Myxobolus neurobius, metacercaria of the genera Diplostomum and Apatemon, and the nematode Raphidascaris acus larvae were the most numerous in salmon parasite fauna. Brown trout had the most number of specific parasite species, whereas char was infested by protozoan parasites only.

  5. Distribution of Po-210 and Pb-210 in Arctic Char (Salvelinus alpinus) from an Arctic freshwater lake

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    Gwynn, J.P.; Rudolfsen, G. [Norwegian Radiation Protection Authority, The Fram Centre, Tromsoe (Norway)

    2014-07-01

    There is little information available with regard to the accumulation of Po-210 and Pb-210 by freshwater fish in natural freshwater systems despite the potential for relevant ingestion doses to man. This is maybe of particular pertinence for certain population groups where freshwater fish are an important dietary food item. Equally, it is important to understand the body distributions of these naturally occurring radionuclides to quantify the resulting doses to different tissues and organs of freshwater fish. With regard to the latter, it is important to consider not only the doses arising from bio-accumulated Po-210 and Pb-210 in various body compartments but additionally the internal dose from unabsorbed Po-210 and Pb-210 in the digestive tract. In this study, activity concentrations of Po-210 and Pb-210 were determined in muscle and various internal organs of Arctic Charr (Salvelinus alpinus) sampled from a lake in the Norwegian Arctic (69 deg. 4' N, 19 deg. 20' E). Observed activity concentrations of Po-210 and Pb-210 in different tissues will be discussed in relation to physiological parameters and ambient lake water activity concentrations. Results from this study will be compared to two similar studies conducted in freshwater systems where elevated activity concentrations of these radionuclides have been observed. Ingestion dose rates to man and effective absorbed dose rates to different tissues and organs of Arctic Charr from Po-210 and Pb-210 will be derived and compared to those from observed activity concentrations of the anthropogenic radionuclide Cs-137. (authors)

  6. Current status, between-year comparisons and maternal transfer of organohalogenated compounds (OHCs) in Arctic char (Salvelinus alpinus) from Bjørnøya, Svalbard (Norway)

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    Bytingsvik, J., E-mail: jenny.bytingsvik@akvaplan.niva.no [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Frantzen, M. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Götsch, A.; Heimstad, E.S. [NILU (Norwegian Institute for Air Research), The Fram Centre, N-9296 Tromsø Norway (Norway); Christensen, G. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); Evenset, A. [Akvaplan-niva AS, The Fram Centre, N-9296 Tromsø Norway (Norway); University of Tromsø, The Arctic University of Norway, Pb 6050 Langnes, N-9037 Tromsø (Norway)

    2015-07-15

    High levels of organohalogenated compounds (OHCs) have been found in Arctic char from Lake Ellasjøen at Bjørnøya (Svalbard, Norway) compared to char from other arctic lakes. The first aim of the study was to investigate the OHC status, contaminant profile, and partitioning of OHCs between muscle and ovary tissue in spawning female char from the high-polluted Lake Ellasjøen and the low-polluted Lake Laksvatn. The second aim was to investigate if OHC levels in muscle tissue have changed over time. Between-lake comparisons show that the muscle levels (lipid weight) of hexachlorobenzene (HCB), chlordanes (∑ CHLs), mirex, dichlorodiphenyltrichloroethanes (∑ DDTs) and polychlorinated biphenyls (∑ PCBs) were up to 36 times higher in char from Ellasjøen than in Laksvatn, and confirm that the char from Ellasjøen are still heavily exposed compared to char from neighboring lake. A higher proportion of persistent OHCs were found in Ellasjøen compared to Laksvatn, while the proportion of the less persistent OHCs was highest in Laksvatn. A between-year comparison of OHC levels (i.e., HCB, DDTs, PCBs) in female and male char shows higher levels of HCB in female char from Ellasjøen in 2009/2012 compared to in 1999/2001. No other between-year differences in OHC levels were found. Due to small study groups, findings associated with between-year differences in OHC levels should be interpreted with caution. OHCs accumulate in the lipid rich ovaries of spawning females, resulting in up to six times higher levels of OHCs in ovaries compared to in muscle (wet weight). The toxic equivalent (TEQ)-value for the dioxin-like PCBs (PCB-105 and -118) in ovaries of the Ellasjøen char exceeded levels associated with increased egg mortality in rainbow trout (Oncorhynchus mykiss). Hence, we suggest that future studies should focus on the reproductive health and performance abilities of the high-exposed population of char inhabiting Lake Ellasjøen. - Highlights: • Examine levels

  7. Laser ablation inductively coupled plasma mass spectrometric analyses of base metals in arctic char (Salvelinus alpinus) otoliths collected from a flooded base metal mine.

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    Friedrich, Lisa A; Halden, Norman M

    2011-05-15

    Otoliths from arctic char recovered from the water body formed from an abandoned open-pit nickel-copper mine contain a trace element record related to the geology of the immediate watershed, past mining activity in the area, and the fish's diet. Laser ablation inductively coupled plasma mass spectrometric analyses across the annular structure of the otoliths detected trace amounts of nickel, copper, and chromium believed to be related to the metal-bearing, mafic-ultramafic minerals in the pit. Oscillatory strontium, barium, and zinc profiles may reflect changing water temperature, diet, or fish metabolism. Lead was detected in very low concentrations and may be related to anthropogenic influence. This closed lake system provides a unique opportunity to study an introduced exotic species in a setting where neither migration nor recruitment have been possible. The fish have successfully occupied the lake and continue to breed despite the influence of the surrounding rocks and local contamination. The chemical record retained within otoliths provides a method of monitoring trace elements affecting fish on a yearly basis and may be regarded as a useful assessment tool for examining the exposure of wild organisms to trace elements.

  8. Genetic structure of the Salvelinus genus chars from reservoirs of the Kuril Islands.

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    Shubina, E A; Ponomareva, E V; Gritsenko, O F

    2007-12-01

    Genetic resemblance of chars Salvelinus alpinus krasheninnikovi (Salvelinus malma krasheninnikovi) of 35 samples collected in five Kuril Islands--Shumshu, Paramushir, Onekotan, Iturup, and Kunashir--has been studied by the PCR-RAPD method. In the limits of each island, both resident isolates and anadromous forms give strictly supported clusters distinct from samples from the other islands. The samples from five islands form three superclusters: the first from Kunashir and Iturup Islands, the second from Paramushir and Onekotan Islands, and the third from Shumshu Island. The possible reasons for genetic similarity of resident and anadromous forms of Dolly Varden chars inhabiting reservoirs of a definite island are considered (the founder effect, homing, limited migration).

  9. Experimental evidence for paternal effects on offspring growth rate in Arctic charr (Salvelinus alpinus)

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    Eilertsen, Eirik Mack; Bårdsen, Bård-Jørgen; Liljedal, Ståle; Rudolfsen, Geir; Folstad, Ivar

    2008-01-01

    Sexual selection theory predicts that females should choose males that signal viability and quality. However, few studies have found fitness benefits among females mating with highly ornamented males. Here, we use Arctic charr (Salvelinus alpinus), a teleost fish with no parental care, to investigate whether females could gain fitness benefits by mating with highly ornamented and large-sized males. Carotenoid-based coloration signalled by males during spawning is believed to be an indicator o...

  10. [Genetic divergence of mitochondrial DNA in white char Salvelinus albus and northern Dolly Varden char Salvelinus malma malma].

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    Oleĭnik, A G; Skurikhina, L A; Brykov, Vl A

    2010-03-01

    Comparative analysis of mitochondrial DNA variation was performed in white char Salvelinus albus and in its putative ancestor species, northern Dolly Varden char Salvelinus malma malma. Highly statistically significant differentiation of S. albus and S. m. malma in the areas of sympatric (Kamchatka River basin) and allopatric (Kronotskoe Lake and Kronotskaya River) residence was demonstrated. The mtDNA divergence between S. albus and S. m. malma did not exceed the range ofintraspecific variation in the populations of northern Dolly Varden char. At the same time, clusterization pattern of the Salvelinus chars provides hypothesis on the common origin of two allopatric populations of white char. Genealogical analysis of haplotypes indicates that S. albus and S. m. malma currently demonstrate incomplete radiation of mitochondrial lineages. The low nucleotide divergence estimates between S. albus and S. m. malma reflect the short time period since the beginning of the radiation of ancestral lineages. These estimates are determined by ancestral polymorphism and haplotype exchange between the diverged phylogenetic groups as a result of introgressive hybridization.

  11. [Genetic Connectivity Between Sympatric Populations of Closely Related Char Species, Dolly Varden Salvelinus malma and White Char Salvelinus albus].

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    Salmenkova, E A

    2016-01-01

    The closely related chars Salvelinus malma and Salvelinus albus, which sympatrically inhabit the Kamchatka River basin and Kronotsky Lake (Kamchatka), attract the attention of the researchers because of their debated origin and taxonomic status. Previous studies of sympatric populations of these chars revealed small but statistically significant genetic differences between these species at a number of molecular markers, suggesting the presence of the genetic exchange and hybridization. In this study, based on genotypic characterization of nine microsatellite loci, a considerable level of historical and contemporary genetic migration between sympatric populations of these chars was demonstrated. At the individual level a high degree of hybridization was observed, mainly among the Dolly Varden individuals from the studied populations. The obtained evidence on the genetic connectivity between sympatric S. malma and S. albus do not support the separate species status of S. albus.

  12. [Population genetic structure of the char species of the Northern Kuril Islands and the rank of the Dolly Varden Char in the system of the genus Salvelinus (Salmonidae: Teleostei)].

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    Shubina, E A; Ponomareva, E V; Gritsenko, O F

    2006-01-01

    Analysis of the taxonomic position of most species and forms of the char (genus Salvelinus, Salmonidae: Teleostei) was made based on RAPD-PCR. The material was represented by samples from 29 populations from the Kuril Islands, coast of the Sea of Okhotsk, Kamchatka, Chukotka, Taymyr, Transbaikalia, the Kola Peninsula, Svalbard, Finland, and North America. It was shown that the genus Salvelinus splits into three well-justified clusters: (1) all the forms assigned to the Salvelinus alpinus--S. malma complex; (2) two samples of the White-Spotted Char from the Southern Kuril Islands and from Kamchatka; (3) two North American species, S. fontinalis and S. namaycush (samples of the North American species S. confluentis were absent from the collection). Analysis of the absolute values of genetic disctances of the S. alpinus--S. malma forms relative to S. leucomaenis, S. fontinalis, and S. namaycush revealed distances approaching the species rank between the following isolates: Frolikh Char, Mountain Char, Black Lake Char, Goggle-Eyed Char, and Neyva Char. Samples of Dolly Varden currently considered as "S. malma", do not constitute a separate cluster, falling within the group of the Arctic char S. alpinus. This conclusion is supported by the analysis of the results of three series of experiments by R. Phillips on ITS1 ribosome genes (Pleute et al., 1992; Phillips et al., 1995; Phillips et al., 1999). This indicates the infraspecific rank of malma within S. alpinus. Isolated populations of "Salvethymus svetovidovi" from the lake Elgygytgyn (Chukotka Peninsula) and of the char from the lake Chyornoye (Onekotan Island), recently described as S. gritzenkoi (Vasil'eva, Stygar, 2000), fell withing the S. alpinus--S. malma complex, the Onekotan char grouped together with another isolate from the same island. Comparison of genetic distances between the samples showed that the differences between the two isolated of Onekotan and migratory forms of the Kuril Islands are

  13. Experimental evidence for paternal effects on offspring growth rate in Arctic charr (Salvelinus alpinus).

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    Eilertsen, Eirik Mack; Bårdsen, Bård-Jørgen; Liljedal, Ståle; Rudolfsen, Geir; Folstad, Ivar

    2009-01-07

    Sexual selection theory predicts that females should choose males that signal viability and quality. However, few studies have found fitness benefits among females mating with highly ornamented males. Here, we use Arctic charr (Salvelinus alpinus), a teleost fish with no parental care, to investigate whether females could gain fitness benefits by mating with highly ornamented and large-sized males. Carotenoid-based coloration signalled by males during spawning is believed to be an indicator of good genes for this species. Paternal effects on offspring size (body length and dry body mass) were examined experimentally by crossing eggs and sperm in vitro from 12 females and 24 males in a split-brood design and raising larvae to 30 days past hatching. We clearly demonstrated that there was a relationship between offspring size and paternal coloration. However, a negative interaction between paternal length and coloration was evident for offspring length, indicating that positive effects of paternal coloration were only present for smaller males. Thus, the red spawning coloration of the male Arctic charr seems to be an indicator of good genes, but the effect of paternal coloration on offspring length, an indicator of 'offspring quality', is size dependent.

  14. Developmental toxicity of selenium to Dolly Varden char (Salvelinus malma).

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    McDonald, Blair G; deBruyn, Adrian M H; Elphick, James R F; Davies, Martin; Bustard, David; Chapman, Peter M

    2010-12-01

    Gametes were collected from Dolly Varden char (Salvelinus malma) from waterbodies in a region exposed to mining-related selenium (Se) releases in British Columbia, Canada. Fertilized eggs were incubated in a laboratory and deformities were assessed on newly-hatched alevins using a graduated severity index. No effects were observed on egg or alevin survival or larval weight across the studied exposure range of 5.4 to 66 mg/kg dry weight in egg. Length of some larvae was reduced at the highest egg Se concentrations and a clear residue-response relationship was observed for larval deformity. The egg concentration corresponding to a 10% increase in the frequency of deformity (EC10) was 54 mg/kg dry weight, which is substantially higher than reported for other cold-water fish species.

  15. PCB impairs smoltification and seawater performance in anadromous Arctic charr (Salvelinus alpinus)

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    Jorgensen, E.H.; Aas-Hansen, O.; Maule, A.G.; Strand, J.E.T.; Vijayan, M.M.

    2004-01-01

    The impacts of polychlorinated biphenyl (PCB) exposure on smoltification and subsequent seawater performance were investigated in hatchery-reared, anadromous Arctic charr (Salvelinus alpinus). The fish were subjected to a 2-month summer seawater residence, after which they were orally dosed with 0 (Control, C), 1 (Low Dose, LD) or 100 mg Aroclor 1254 kg-1 body mass (High Dose, HD) in November. They were then held in fresh water, without being fed (to mimic their natural overwintering in freshwater), until they had smolted in June the next year. The smolts were then transferred to seawater and fed to mimic their summer feeding residence in seawater, followed by a period without food in freshwater from August until maturation in October. Compared with C and LD charr, the HD charr had either a transient or a permanent reduction in plasma growth hormone, insulin-like growth factor-1, and thyroxin and triiodothyronine titers during the period of smoltification. These hormonal alterations in the HD charr corresponded with impaired hyposmoregulatory ability in May and June, as well as reduced growth rate and survival after transference to seawater. Consequently, fewer fish in the HD group matured in October compared to the other two treatments. The HD fish had a liver PCB concentration ranging between 14 and 42 mg kg-1 wet mass, whereas there were similar, and very low, liver PCB concentrations in LD and C fish throughout the smolting period. Our findings suggest that PCB might compromise mechanisms important for fitness in a fish species living in an extreme environment. ?? 2004 Elsevier Inc. All rights reserved.

  16. Changes in arterial oxygen tension and physiological status in resting, unrestrained Arctic charr Salvelinus alpinus (L.) exposed to mild hypoxia and hyperoxia.

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    Karlsson, A; Rosseland, B O; Thorarensen, H; Kiessling, A

    2011-03-01

    In arctic charr Salvelinus alpinus, arterial blood partial pressures of oxygen (PaO2) and carbon dioxide increased with increasing water oxygen tension (PwO2), while the water to arterial PO2 difference (PwO2-PaO2) did not change in relation to PwO2.

  17. The genetic basis of salinity tolerance traits in Arctic charr (Salvelinus alpinus

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    Glebe Brian

    2011-09-01

    Full Text Available Abstract Background The capacity to maintain internal ion homeostasis amidst changing conditions is particularly important for teleost fishes whose reproductive cycle is dependent upon movement from freshwater to seawater. Although the physiology of seawater osmoregulation in mitochondria-rich cells of fish gill epithelium is well understood, less is known about the underlying causes of inter- and intraspecific variation in salinity tolerance. We used a genome-scan approach in Arctic charr (Salvelinus alpinus to map quantitative trait loci (QTL correlated with variation in four salinity tolerance performance traits and six body size traits. Comparative genomics approaches allowed us to infer whether allelic variation at candidate gene loci (e.g., ATP1α1b, NKCC1, CFTR, and cldn10e could have underlain observed variation. Results Combined parental analyses yielded genome-wide significant QTL on linkage groups 8, 14 and 20 for salinity tolerance performance traits, and on 1, 19, 20 and 28 for body size traits. Several QTL exhibited chromosome-wide significance. Among the salinity tolerance performance QTL, trait co-localizations occurred on chromosomes 1, 4, 7, 18 and 20, while the greatest experimental variation was explained by QTL on chromosomes 20 (19.9%, 19 (14.2%, 4 (14.1% and 12 (13.1%. Several QTL localized to linkage groups exhibiting homeologous affinities, and multiple QTL mapped to regions homologous with the positions of candidate gene loci in other teleosts. There was no gene × environment interaction among body size QTL and ambient salinity. Conclusions Variation in salinity tolerance capacity can be mapped to a subset of Arctic charr genomic regions that significantly influence performance in a seawater environment. The detection of QTL on linkage group 12 was consistent with the hypothesis that variation in salinity tolerance may be affected by allelic variation at the ATP1α1b locus. IGF2 may also affect salinity tolerance

  18. Complete mitochondrial genomes of the Northern (Salvelinus malma) and Southern (Salvelinus curilus) Dolly Varden chars (Salmoniformes, Salmonidae).

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    Balakirev, Evgeniy S; Romanov, Nikolai S; Ayala, Francisco J

    2016-01-01

    The complete mitochondrial genomes were sequenced from the Northern and Southern Dolly Varden chars, Salvelinus malma and S. curilus. The genome sequences are 16,654 bp in size in both species, and the gene arrangement, composition, and size are very similar to the salmonid fish genomes published previously. The level of sequence divergence between S. malma and S. curilus inferred from the complete mitochondrial genomes is relatively low (1.88%) indicating recent divergence of the species and/or historical hybridization.

  19. Differentiation at the MHCIIα and Cath2 loci in sympatric Salvelinus alpinus resource morphs in Lake Thingvallavatn.

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    Kalina H Kapralova

    Full Text Available Northern freshwater fish may be suitable for the genetic dissection of ecological traits because they invaded new habitats after the last ice age (∼10.000 years ago. Arctic charr (Salvelinus alpinus colonizing streams and lakes in Iceland gave rise to multiple populations of small benthic morphotypes, often in sympatry with a pelagic morphotype. Earlier studies have revealed significant, but subtle, genetic differentiation between the three most common morphs in Lake Thingvallavatn. We conducted a population genetic screen on four immunological candidate genes Cathelicidin 2 (Cath2, Hepcidin (Hamp, Liver expressed antimicrobial peptide 2a (Leap-2a, and Major Histocompatibility Complex IIα (MHCIIα and a mitochondrial marker (D-loop among the three most common Lake Thingvallavatn charr morphs. Significant differences in allele frequencies were found between morphs at the Cath2 and MHCIIα loci. No such signal was detected in the D-loop nor in the other two immunological genes. In Cath2 the small benthic morph deviated from the other two (FST  = 0.13, one of the substitutions detected constituting an amino acid replacement polymorphism in the antimicrobial peptide. A more striking difference was found in the MHCIIα. Two haplotypes were very common in the lake, and their frequency differed greatly between the morphotypes (from 22% to 93.5%, FST  = 0.67. We then expanded our study by surveying the variation in Cath2 and MHCIIα in 9 Arctic charr populations from around Iceland. The populations varied greatly in terms of allele frequencies at Cath2, but the variation did not correlate with morphotype. At the MHCIIα locus, the variation was nearly identical to the variation in the two benthic morphs of Lake Thingvallavatn. The results are consistent with a scenario where parts of the immune systems have diverged substantially among Arctic charr populations in Iceland, after colonizing the island ∼10.000 years ago.

  20. [Population genetic structure of northern Dolly Varden char Salvelinus malma malma in Asia and North America].

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    Oleĭnik, A G; Skurikhina, L A; Brykov, Vl A

    2011-12-01

    The level of genetic differentiation of northern Dolly Varden char Salvelinus malma malma from Asia and North America was evaluated using the data on mtDNA variation (regions ND1/ND2, ND5/ND6, and Cytb/D loop) obtained by means of PCR-RFLP analysis. For S. m. malma, the mean values of haplotype and nucleotide diversity were 0.5261 +/- 0.00388 and 0.001558, respectively. The mean estimate of the population nucleotide divergence constituted 0.055%. It was demonstrated that S. m. malma on the most part of the species range examined (drainages of the Beaufort Sea, Chukotka Sea, Bering Sea, and the Sea of Okhotsk) was characterized by the population genetic structure with the low level of genetic differentiation and divergence. At the same time, populations from the Pacific Ocean Gulf of Alaska demonstrated marked genetic differentiation, supported by the high pairwise phi(ST) values (from 0.4198 to 0.5211) and nucleotide divergence estimates (mean divergence, 0.129%), from Asian and North American populations. Nested analysis of molecular variance (AMOVA) showed that most of the mtDNA variation in S. m. malma fell in the intrapopulation component (72.5%). At the same time, the differences between the populations (21.1%) and between the regions (6.4%) made lower contribution to the total variation.

  1. Seasonal Differences in Relative Gene Expression of Putative Central Appetite Regulators in Arctic Charr (Salvelinus alpinus Do Not Reflect Its Annual Feeding Cycle.

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    Anja Striberny

    Full Text Available The highly seasonal anadromous Arctic charr (Salvelinus alpinus was used to investigate the possible involvement of altered gene expression of brain neuropeptides in seasonal appetite regulation. Pro-opiomelanocortin (POMCA1, POMCA2, Cocaine and amphetamine regulated transcript (CART, Agouti related Peptide (AgRP, Neuropeptide Y (NPY and Melanocortin Receptor 4 (MC4-R genes were examined. The function of centrally expressed Leptin (Lep in fish remains unclear, so Lep (LepA1, LepA2 and Leptin Receptor (LepR genes were included in the investigation. In a ten months study gene expression was analysed in hypothalamus, mesencephalon and telencephalon of immature charr held under natural photoperiod (69°38'N and ambient temperature and given excess feed. From April to the beginning of June the charr did not feed and lost weight, during July and August they were feeding and had a marked increase in weight and condition factor, and from November until the end of the study the charr lost appetite and decreased in weight and condition factor. Brain compartments were sampled from non-feeding charr (May, feeding charr (July, and non-feeding charr (January. Reverse transcription real-time quantitative PCR revealed temporal patterns of gene expression that differed across brain compartments. The non-feeding charr (May, January had a lower expression of the anorexigenic LepA1, MC4-R and LepR in hypothalamus and a higher expression of the orexigenic NPY and AgRP in mesencephalon, than the feeding charr (July. In the telencephalon, LepR was more highly expressed in January and May than in July. These results do not indicate that changes in central gene expression of the neuropeptides investigated here directly induce seasonal changes in feeding in Arctic charr.

  2. [The divergence of the dolly varden char Salvelinus malma in Asian Northern Pacific populations inferred from the PCR-RFLP analysis of the mitochondrial DNA].

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    Oleĭnik, A G; Skurikhina, L A; Brykov, V A

    2002-10-01

    Genetic differentiation of the dolly varden char Salvelinus malma Walbaum was studied in five populations from the western part of the Northern Pacific. Using restriction analysis (RFLP), we examined polymorphism of three mitochondrial DNA (mtDNA) fragments amplified in polymerase chain reaction (PCR). MtDNA haplotypes were shown to fall into two phylogenetic groups, which probably reflect the existence of two previously described subspecies of Asian dolly varden, S. malma malma and S. malma krascheninnikovi. The divergence of mtDNA nucleotide sequences in the dolly varden subspecies (about 4%) corresponds to the differences between the valid char species from the genus Salvelinus.

  3. [Phylogeography of mitochondrial DNA in South Asian Dolly Varden char Salvelinus curilus Pallas, 1814 (Salmoniformes, Salmonidae): mediated gene introgression?].

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    Shed'ko, S V; Ginatulina, L K; Miroshnichenko, I L; Nemkova, G A

    2007-02-01

    In 41 individuals of South Asian Dolly Varden char Salvelinus curilus, nucleotide sequences of tRNA-Pro gene fragment (27 bp) and mtDNA control region (483-484 bp) were analyzed. The fish were collected in 20 localities covering virtually the whole range of the species: Kuril Islands, Sakhalin Island. and Primorye. In addition, six individuals of three other char species (S. albus, S. malma, and S. leucomaenis), which are closely related to S. curilus and inhabit the Russian Far East, were examined. In all, we detected 12 different variants of mtDNA haplotypes that formed three distinct groups differing in 14--20 nucleotide positions. The first group consisted of six haplotypes found in S. curilus in Kuril Islands, Sakhalin, and Primorye (mtDNA phylogroup OKHOTSKIA). The second group comprised four haplotypes representing the mtDNA phylogroup BERING, which had been described earlier (Brunner et al, 2001); they were found in S. curilus in Kuril Islands and Sakhalin, as well as in S. albus and S. malma in Kamchatka and northern Kurils. The third group included two haplotypes detected in S. leucomaenis. The existence of two mtDNA lineages (OKHOTSKIA and BERING) in S. curilus from Kurils and Sakhalin was explained by hybridization and DNA transfer from S. malma to S. curilus. The absence of the BERING haplotypes in S. curilus from Primorye water reservoirs is related to the physical isolation of the Sea of Okhotsk and Sea of Japan basins in past epochs. On the basis of comparing phylogenetic trees, constructed from the data on allozyme and mtDNA variation, we suggest that in this case, an indirect transfer of mtDNA in Alpinoid chars--> S. malma-->S. curilus chain could occur.

  4. Understanding environmental DNA detection probabilities: A case study using a stream-dwelling char Salvelinus fontinalis

    Science.gov (United States)

    Wilcox, Taylor M; Mckelvey, Kevin S.; Young, Michael K.; Sepulveda, Adam; Shepard, Bradley B.; Jane, Stephen F; Whiteley, Andrew R.; Lowe, Winsor H.; Schwartz, Michael K.

    2016-01-01

    Environmental DNA sampling (eDNA) has emerged as a powerful tool for detecting aquatic animals. Previous research suggests that eDNA methods are substantially more sensitive than traditional sampling. However, the factors influencing eDNA detection and the resulting sampling costs are still not well understood. Here we use multiple experiments to derive independent estimates of eDNA production rates and downstream persistence from brook trout (Salvelinus fontinalis) in streams. We use these estimates to parameterize models comparing the false negative detection rates of eDNA sampling and traditional backpack electrofishing. We find that using the protocols in this study eDNA had reasonable detection probabilities at extremely low animal densities (e.g., probability of detection 0.18 at densities of one fish per stream kilometer) and very high detection probabilities at population-level densities (e.g., probability of detection > 0.99 at densities of ≥ 3 fish per 100 m). This is substantially more sensitive than traditional electrofishing for determining the presence of brook trout and may translate into important cost savings when animals are rare. Our findings are consistent with a growing body of literature showing that eDNA sampling is a powerful tool for the detection of aquatic species, particularly those that are rare and difficult to sample using traditional methods.

  5. [Phylogeography of southern Asian Dolly Varden char Salvelinus malma krascheninnikovi: genealogical analysis of mitochondrial DNA].

    Science.gov (United States)

    Oleĭnik, A G; Skurikhina, L A; Chukova, E I

    2010-02-01

    Phylogeography of southern Asian Dolly Varden char was studied using the data on mtDNA variation (regions ND1/ND2, ND5/ND6, and Cytb/D loop) obtained using PCR-RFLP analysis. Analysis of contemporary population genetic structure showed that S. m. krascheninnikovi throughout the whole species range was characterized by high population differentiation in combination with rather small differences between the populations from remote regions. The genealogy of mtDNA haplotypes was reconstructed and nested clade analysis of geographical distances was performed. Geographical distribution of mtDNA haplotypes of S. m. krascheninnikovi was explained by population genetic processes (restricted gene flow), as well as by historical demographic events (range expansion and fragmentation). It was demonstrated that the main demographic events were associated with cyclic processes of the geological formation of the Sea of Japan and adjacent territories. Furthermore, genealogical tree of S. m. krascheninnikovi contained the traces of secondary contact between isolated phylogeographical lineages.

  6. [Karyological differences of the Northern Dolly Varden Salvelinus malma malma and the white char Salvelinus albus from the Kamchatka River basin].

    Science.gov (United States)

    Frolov, S V

    2001-03-01

    The karyotypes of northern Dolly Varden and white char, sympathrically inhabiting the Kamchatka River basin, were studied. The karyotype of Dolly Varden was stable: 2n = 78 and NF = 98 + 2, while in white char, polymorphism and mosaicism for the chromosome number were revealed: 2n = 76-79, NF = 98 + 2. Using a routine chromosome staining technique, the karyotype of white char (2n = 78) was shown to be identical to that of Dolly Varden. In both karyotypes, similar sets of marker chromosomes were present: two pairs of submetacentric (SM), one pair of submeta-subtelocentric (SM-ST), one pair of large acrocentric (A), and one pair of large sub-telocentric (ST) chromosomes. However, the karyotypes of Dolly Varden and white char differed in the number and location of nucleolus organizer regions (NORs). In Dolly Varden, single NORs located in the telomeric regions of the marker SM-ST chromosomes were observed. In white char, NORs were multiple and located both in the telomeric regions of the marker SM-ST chromosomes and on the short and long arms of large ST chromosomes. The identical marker chromosomes indicate considerable phylogenetic relatedness between Dolly Varden and white char from the Kamchatka River basin. Variation in NORs provides evidence for the reproductive isolation of these chars and their species status.

  7. [Differentiation of Dolly Varden char Salvelinus malma from Asia and North America inferred from PCR-RFLP analysis of mitochondrial DNA].

    Science.gov (United States)

    Oleĭnik, A G; Skurikhina, L A; Brykov, V A; Crane, P A; Wenburg, J K

    2005-05-01

    Genetic differentiation of Dolly Varden char Salvelinus malma Walbaum from the Asian and North American Pacific coasts was studied. We examined restriction fragment length polymorphism of three mitochondrial DNA (mtDNA) fragments amplified in polymerase chain reaction, which encoded four NADH dehydrogenase subunits, the cytochrome b gene, and a D-loop segment. The mtDNA haplotypes were shown to form three phylogenetic groups, whose geographic distribution corresponded to three Dolly Varden subspecies: S. malma malma, S. malma krascheninnikovi, and S. malma lordi. The nucleotide sequence divergence between S. malma malma and S. malma krascheninnikovi was 3.8%; between S. malma malma and S. malma lordi, 3.1%; and between S. malma krascheninnikovi and S. malma lordi, 2.5%. The northern Dolly Varden S. malma malma from Asia was shown to be genetically identical to that from North America.

  8. Understanding how lake populations of arctic char are structured and function with special consideration of the potential effects of climate change: a multi-faceted approach.

    Science.gov (United States)

    Budy, Phaedra; Luecke, Chris

    2014-09-01

    Size dimorphism in fish populations, both its causes and consequences, has been an area of considerable focus; however, uncertainty remains whether size dimorphism is dynamic or stabilizing and about the role of exogenous factors. Here, we explored patterns among empirical vital rates, population structure, abundance and trend, and predicted the effects of climate change on populations of arctic char (Salvelinus alpinus) in two lakes. Both populations cycle dramatically between dominance by small (≤300 mm) and large (>300 mm) char. Apparent survival (Φ) and specific growth rates (SGR) were relatively high (40-96%; SGR range 0.03-1.5%) and comparable to those of conspecifics at lower latitudes. Climate change scenarios mimicked observed patterns of warming and resulted in temperatures closer to optimal for char growth (15.15 °C) and a longer growing season. An increase in consumption rates (28-34%) under climate change scenarios led to much greater growth rates (23-34%). Higher growth rates predicted under climate change resulted in an even greater predicted amplitude of cycles in population structure as well as an increase in reproductive output (Ro) and decrease in generation time (Go). Collectively, these results indicate arctic char populations (not just individuals) are extremely sensitive to small changes in the number of ice-free days. We hypothesize years with a longer growing season, predicted to occur more often under climate change, produce elevated growth rates of small char and act in a manner similar to a "resource pulse," allowing a sub-set of small char to "break through," thus setting the cycle in population structure.

  9. Cesium in Arctic char lakes - effects of the Chernobyl accident. Radioaktivt cesium i roedingsjoear - effekter av Tjernobylkatastrofen

    Energy Technology Data Exchange (ETDEWEB)

    Hammar, J. (Fiskeriverkets Soetvattenslaboratorium, Drottningholm (Sweden)); Notter, M.; Neumann, G. (Statens Naturvaardesverks Miljoekontrollaboratorium, Drottningholm (Sweden))

    1991-01-01

    Fallout radiocesium from the Chernobyl accident caused extensive contamination in a region of previously well studied alpine lake ecosystems in northern Sweden. Levels of Cs-137 in the barren catchment basins reached 20-50 kBq/m[sup 2] during 1986. The distribution, pathways and major transport mechanisms of radiocesium through the lake ecosystems were studied during 1986-1990. Levels of Cs-137, Cs-134 and K-40 in water, surface sediment, detritus (sediment traps) and different trophic levels of the food chains of Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) were monitored in a series of lakes forming a matrix of 4 natural lakes and 3 lake reservoirs, with or without the introduced new fish food organism, Mysis relicta. The reservoirs were found to act as sinks for radiocesium with extensive accumulation recorded in water, detritus, sediment, invertebrates and salmonids. Whereas concentrations in water and biota have declined from the extreme peak levels in 1986-1987, the levels in surface sediment increased extensively until fall of 1988. The concentration of Cs-137 in fish populations feeding on benthic invertebrates, i.e. mysids and amphipods, were significantly higher than in planktivorous fish. During the three first winters a significant increase in levels of Cs-137 in winter active Arctic char were recorded, whereas the levels declined during the succeeding summers. The introduced Mysis relicta were found to enhance the transport of Cs-137 from zooplankton and settling particles to Arctic char and brown trout. The results suggest a successive change in transport of radiocesium from water via zooplankton to planktivorous fish during the early summer of 1986 to post-depositional mobilization via benthic organisms to benthic fish in successive years. (213 refs.) (au).

  10. Population connectivity: dam migration mitigations and contemporary site fidelity in arctic char

    Directory of Open Access Journals (Sweden)

    Heggenes Jan

    2011-07-01

    Full Text Available Abstract Background Animal feeding and spawning migrations may be limited by physical barriers and behavioral interactions. Dam constructions (e.g. hydropower commonly include gateways for fish migrations to sustain ecological connectivity. Relative genetic impacts of fish passage devices versus natural processes (e.g. hybrid inferiority are, however, rarely studied. We examined genetic (i.e. microsatellite population connectivity of highly migrating lake-dwelling Arctic char (Salvelinus alpinus, introduced 20 generations ago, across and within two subalpine lakes separated by a dam with a subterranean tunnel and spill gates after 7 generations. Due to water flow regime, the time window for fish migration is highly restricted. Results Char populations, with similar genetic structuring and diversity observed across and within lakes, were admixed across the dam with fishways during feeding. For spawning, however, statistically significant, but very low population differentiation (θ; 0.002 - 0.013 was found in nine out of ten reproductive site comparisons, reflecting interactions between extensive migration (mean first generation (F0 = 10.8% and initial site fidelity. Simulations indicated that genetic drift among relatively small effective populations (mean Ne = 62 may have caused the observed contemporary differentiation. Novel Bayesian analyses indicated mean contributions of 71% F0 population hybrids in spawning populations, of which 76% had maternal or paternal native origin. Conclusions Ecological connectivity between lakes separated by a dam has been retained through construction of fishways for feeding migration. Considerable survival and homing to ancestral spawning sites in hybrid progeny was documented. Population differentiation despite preceding admixture is likely caused by contemporary reduced reproductive fitness of population hybrids. The study documents the beginning stages of population divergence among spatial aggregations with

  11. Phylogeography of the salmonid fish, Dolly Varden Salvelinus malma: multiple glacial refugia in the North Pacific Rim.

    Science.gov (United States)

    Yamamoto, Shoichiro; Maekawa, Koji; Morita, Kentaro; Crane, Penelope A; Oleinik, Alla G

    2014-10-01

    The geographic distribution pattern of mitochondrial DNA (control region) sequence polymorphisms from 73 populations of a salmonid fish, Dolly Varden Salvelinus malma, over most of its range in the North Pacific rim, was examined to assess how its spatial population genetic structure has been molded. The observed 68 haplotypes were grouped into three main lineages, which correspond to western, central, and eastern regions in the North Pacific. The two outlier-haplotype groups gave close agreement with DNA types from two congeneric species, white-spotted charr S. leucomaenis and Arctic charr S. alpinus, respectively. These results suggest that the present-day genetic structure of S. malma reflects historical patterns of isolation and re-colonization, and also historical hybridization with co-distributed species. We also placed the haplotypes of S. malma within our study areas into a pre-existing evolutionary relationship of S. alpinus and S. malma throughout the Northern Hemisphere. Phylogenetic analysis revealed that the Western Lineage S. malma was basal to all other lineages of S. malma and S. alpinus. Our data serve as a biogeographic hypothesis for salmonid fishes that the Sea of Japan and/or Sea of Okhotsk regions represents a place of origin for S. malma and S. alpinus groups currently distributed in circumpolar regions.

  12. [Variability of nucleotide sequences of the mitochondrial DNA cytochrome c gene in dolly varden and taranetz char].

    Science.gov (United States)

    Radchenko, O A; Derenko, M V; Maliarchuk, B A

    2000-07-01

    Nucleotide sequence of the 307-bp fragment of the mitochondrial DNA cytochrome b gene was determined in representatives of the three species of the Salvelinus genus, specifically, dolly varden char (S. malma), taranetz char (S. taranetzi), and white-spotted char (S. leucomaenis). These results pointed to a high level of mitochondrial DNA (mtDNA) divergence between white-spotted char and dolly varden char, on the one hand, and taranetz char, on the other (the mean d value was 5.45%). However, the divergence between the dolly varden char and taranetz char was only 0.81%, which is comparable with the level of intraspecific divergence in the dolly varden char (d = 0.87%). It was shown that the dolly varden char mitochondrial gene pool contained DNA lineages differing from the main mtDNA pool at least in the taranetz char-specific mitochondrial lineages. One of these dolly varden char mtDNA lineages was characterized by the presence of the restriction endonuclease MspI-D variant of the cytochrome b gene. This lineage was widely distributed in the Chukotka populations but it was not detected in the Yana River (Okhotsk sea) populations. These findings suggest that dolly varden char has a more ancient evolutionary lineage, diverging from the common ancestor earlier than did taranetz char.

  13. Beneficiated coals' char morphology

    Directory of Open Access Journals (Sweden)

    Diana Vargas

    2012-09-01

    Full Text Available This work evaluated the char morphology of beneficiated and original coal (without beneficiation from four Colombian coalmines: Cerrejón (La Guajira, La Jagua (Cesar, Guachinte (Valle del Cauca and Nechí (Antioquia. Column flotation was used to obtain beneficiated coal, whereas a drop tube reactor at 1,000°C, 104 °C/s heating rate and 100 ms residence time was used to obtain char. The chars were analysed by image analysis which determined their shape, size, porosity and wall thickness. It was found that char morphology depended on coal rank and maceral composition. Morphological characteristics like high porosity, thinner walls and network-like morphology which are beneficial in improving combustion were present in vitrinite- and liptinite-rich lowest-ranking coals. Beneficiated coals showed that their chars had better performance regarding their morphological characteristics than their original coal chars.

  14. Effects of microbe- and mussel-based diets on the gut microbiota in Arctic charr (Salvelinus alpinus

    Directory of Open Access Journals (Sweden)

    Andreas Nyman

    2017-02-01

    Lactic acid bacteria were a dominant fraction of the intestinal microbiota in Arctic charr. Microbial based feeds were associated with similar changes in microbiota composition, but contrasting to the fish-meal based reference diet. Microbiota composition was similar in the proximal and distal gut, but dietary responses were specific to gut segment.

  15. Influence of o'p-DDD on the physiological response to stress in Arctic charr (Salvelinus alpinus).

    Science.gov (United States)

    Jørgensen, E H; Balm, P H; Christiansen, J S; Plotitsyna, N; Ingebrigtsen, K

    2001-10-01

    Various toxicants have previously been held responsible for an impaired capacity of fish from polluted environments to elevate their cortisol levels in response to stress. In the present study we investigated the responses to stress in o'p-DDD [2-(chlorophenyl)-2-(4-chlorphenyl)-1,1-dichloroethane] exposed (given a single, oral dose of 75 mg o'p-DDD/kg fish) and unexposed Arctic charr. After o'p-DDD administration fish were left undisturbed and without being fed for 28 days, when they were subjected to an acute handling stress. At 1, 3, 7 and 23 h following stress, primary (ACTH and cortisol secretion) and secondary (plasma Cl levels and energy mobilisation) components of the stress response were monitored. As the nutritional state of wild fish may influence this potential biomarker response, the fish had been subjected to a restricted feed ration prior to o'p-DDD administration in order to obtain marked within-group variations in condition factor. No effects of o'p-DDD were observed on post-stress hormone secretion (i.e. peak post-stress plasma ACTH and cortisol levels), nor on plasma chloride levels. However, other results obtained provided evidence for a metabolic depression by o'p-DDD, witnessed by consistently lower plasma glucose levels before and after stress in these contaminated fish. This may be related to the finding that during the 30-day period between o'p-DDD administration and stress treatment, toxicant treated fish lost less weight in comparison to their sham-treated counterparts. Nutritional state did not appear to influence the performance of the charr in the present experiment, as correlations between the parameters measured and condition factor or lipid contents on an individual basis in all cases turned out non significant. Overall, the results contrast with those of previous in vivo and in vitro studies on fish, which concluded that comparable headkidney o'p-DDD levels impaired interrenal steroidogenesis. Although we conclude that the effects of o'p-DDD on Arctic charr metabolism were not associated with the stress response, we propose that they may well interfere with the animals' ability to cope with stress in the long term, or may compromise other physiological processes, such as smoltification. Finally, the high level of integration of components involved in the stress response complicates the identification of single stress-sensitive indices as biomarkers applicable in environmental monitoring programmes.

  16. Time resolved pyrolysis of char

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

    In laboratory experiments, biomass char was produced under controlled conditions using wood chips from French pinewood. Different char qualities were obtained by pyrolysing the biomass at similar heating rates with end-temperatures ranging from 250 to 1000 o C. The char was analysed by flash...

  17. Combustion char characterisation. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, P.; Ingermann Petersen, H.; Sund Soerensen, H.; Thomsen, E.; Guvad, C.

    1996-06-01

    The aim was to correlate reactivity measures of raw coals and the maceral concentrates of the coals obtained in a previous project with the morphology of the produced chars by using a wire grid devolatilization method. Work involved determination of morphology, macroporosity and a detailed study by Scanning Electron Microscopy (SEM). Systematic variations in the texture of chars produced in different temperature domains and heating rates were demonstrated by using incident light microscopy on polished blocks and by SEM studies directly on the surfaces of untreated particles. Results suggest that work in the field of char reactivity estimates and correlations between char morphology and coal petrography can be accomplished only on chars produced under heating rates and temperatures comparable to those for the intended use of coal. A general correlation between the coals` petrography and the the morphology of high temperature chars was found. The SEM study of the chars revealed that during the devolatilization period the particles fuse and the macroporosity and thus the morphotypes are formed. After devolatilization ceases, secondary micropores are formed. These develop in number and size throughout the medium combustion interval. At the end of the combustion interval the macrostructure breaks down, caused by coalescence of the increased number of microspores. This can be observed as a change in the morphology and the macroporosity of the chars. Results indicate that char reactivity is a function of the macroporosity and thus the morphology of combustion chars. (AB) 34 refs.

  18. Characterization of chars form biomass-derived materials: pectin chars

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, R.K.; Wooten, J.B.; Baliga, V.L.; Hajaligol, M.R. [Philip Morris USA, Richmond, VA (United States). Research Center

    2001-10-09

    The effect of pyrolysis conditions on the yield and composition of char from pectin was studied. The volatile product was analyzed by gas chromatography/mass spectrometry (GC/MS). The solid product, i.e. char, was characterised by solid-state {sup 13}C nuclear magnetic resonance (NMR) and Fourier-transform infrared (FTIR) spectrsocopy. The char was also analysed for its elemental composition and surface area. The surface morphology of the char was studied by scanning electron microscopy (SEM). The results were compared to those from chlorogenic acid (CA). For both pectin and CA, the char yield decreased with increasing temperature before levelling-off at ca.20% of the starting substrate in non-oxidative runs. In oxidative runs, the char yields from both substrates became negligible at 550{degree}C. NMR analysis indicated that the aromatic character of char increased as the pyrolysis temperature increased. The oxygen functionality was progressively lost and the resonance bands corresponding to carbonyl groups mostly disappeared above 350{degree}C. FTIR analysis also suggested the loss of hydroxyl and carbonyl groups from chars at high temperatures. The H/C and O/C ratios of chars decreased continuously with increasing temperature. The oxidative chars showed characteristics essentially similar to those of the non-oxidative chars. The surface area of char was negligible at low temperatures, but increased dramatically to a maximum of 70 m{sup 2}g{sup -1} at 450{degree}C before decreasing at 500{degree}C. SEM analysis indicated that the pyrolysis of pectin occurred via softening and melting of the substrate followed by bubble formation. At high temperatures, surface etching followed by the appearance of crystal

  19. Effect of pyrolysis conditions and composition on the char structure and char yield of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut

    The char yield as well as physical and chemical structure of chars generated from different types of biomass divided into five different particle size fractions from 50μm to 1mm were studied to better understand the influences of holding time, final temperatures and heating rates on the pyrolysis...... characteristics of biomass chars. An additional study of the char phase-organic transformation was conducted on the biomass organic matter. Char samples were generated in a wire-mesh reactor up to 1400°C, and with the heating rates between 10 K/s and 3000 K/s. The results were compared with the data gained from...... slow (10 K/min) and fast heating (600 K/min) by thermogravimetric analysis (TGA). Scanning electron microscopy (SEM/EDS), elementary analysis and Fourier transform infrared spectroscopy (FTIR) were conducted to determine the effect of operating conditions and the biomass composition on the char...

  20. Genetics Home Reference: Char syndrome

    Science.gov (United States)

    ... a distinctive facial appearance, a heart defect called patent ductus arteriosus, and hand abnormalities. Most people with Char syndrome ... a triangular-shaped mouth, and thick, prominent lips. Patent ductus arteriosus is a common heart defect in newborns, and ...

  1. Coal char fragmentation during pulverized coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, L.L.

    1995-07-01

    A series of investigations of coal and char fragmentation during pulverized coal combustion is reported for a suite of coals ranging in rank from lignite to low-volatile (lv) bituminous coal under combustion conditions similar to those found in commercial-scale boilers. Experimental measurements are described that utilize identical particle sizing characteristics to determine initial and final size distributions. Mechanistic interpretation of the data suggest that coal fragmentation is an insignificant event and that char fragmentation is controlled by char structure. Chars forming cenospheres fragment more extensively than solid chars. Among the chars that fragment, large particles produce more fine material than small particles. In all cases, coal and char fragmentation are seen to be sufficiently minor as to be relatively insignificant factors influencing fly ash size distribution, particle loading, and char burnout.

  2. The behavioural repertoire of Arctic charr (Salvelinus alpinus (L.)) in captivity: A case study for testing ethogram completeness and reducing observer effects

    OpenAIRE

    Bolgan, Marta; O'Brien, Joanne; Gammell, Martin

    2015-01-01

    In the last 20 years, research has been directed towards possible differences in the mating behaviour of species belonging to the Salmonidae family that may reproductively isolate wild populations from escaped hatchery or farmed fish. Despite these studies, a detailed description of the overall behavioural repertoire of Salmonidae species from wild and farmed environments is still lacking. Furthermore, although Arctic charr has been described as the most variable between all vertebrate specie...

  3. Induction and viability of tetraploids in brook trout (Salvelinus fontinalis)

    Science.gov (United States)

    Brook trout (Salvelinus fontinalis) populations are threatened by introduction of invasive species, habitat loss, and habitat degradation in their native range; and are a problem invasive species in western Unites States and Canada, and in Europe. Stocking sterile triploids has been promoted as an ...

  4. A new feeding group within larval Drusinae (Trichoptera: Limnephilidae): the alpinus-group sensu Schmid, 1956, including larval descriptions of Drusus franzi Schmid, 1956 and Drusus alpinus (Meyer-Dür, 1875)

    Science.gov (United States)

    GRAF, W.; WARINGER, J.; PAULS, S.U.

    2016-01-01

    This paper presents a description of the hitherto unknown larvae of Drusus franzi Schmid 1956, and Drusus alpinus (Meyer-Dür 1875). Information on the morphological and genetic identification of both species is given, and the most important diagnostic features are illustrated. Their systematic position within the genus Drusus is affirmed and zoogeographical and ecological notes are added. PMID:27069350

  5. Food habits of dhole Cuon alpinus in Kalakad-Mundanthurai Tiger Reserve in Tamil Nadu, India

    Directory of Open Access Journals (Sweden)

    K. Muthamizh Selvan

    2013-07-01

    Full Text Available Food habits of dhole Cuon alpinus studied in Kalakad-Mundanthurai Tiger Reserve from January 2010 to July 2010 by analyzing 78 scats. Ten prey species were consumed by dholes in which Sambar was consumed highest percentage (30.77% followed by wild pig (23.08% and lowest was Jungle fowl (0.063%. In terms of biomass contribution sambar was highest (78.70% while jungle fowl was lowest contribution (3.85%. The total prey biomass consumed by dhole was 191.72 kg during our study period. This study will give basic information on food habits of dhole and also gives basic idea for better management strategies to protect this elegant carnivore.

  6. Farming different species in RAS in Nordic countries: Current status and future perspectives

    DEFF Research Database (Denmark)

    Dalsgaard, Anne Johanne Tang; Lund, Ivar; Thorarinsdottir, Ragnheidur

    2013-01-01

    (Oncorhynchus mykiss), European eel (Anguilla anguilla), pike perch (Stizostedion lucioperca), Arctic char (Salvelinus alpinus), sturgeon (order Acipenseriformes), Nile tilapia (Oreochromis niloticus), and European lobster (Homarus gammarus). High capital costs are one of the biggest challenges to sustainable...... RAS calling for large scale intensive productions to reduce investment -and operation costs. Consistent with this, production of Atlantic salmon smolts in indoor RAS and rainbow trout in outdoor Model-Trout-Farms (MTFs) have been the commercially most successful productions so far. Aside from end...

  7. Combustion of char from plastic wastes pyrolysis

    Science.gov (United States)

    Saptoadi, Harwin; Rohmat, Tri Agung; Sutoyo

    2016-06-01

    A popular method to recycle plastic wastes is pyrolysis, where oil, gas and char can be produced. These products can be utilized as fuels because they are basically hydrocarbons. The research investigates char properties, including their performance as fuel briquettes. There are 13 char samples from PE (Polyethylene) pyrolyzed at temperatures of around 450 °C, with and without a catalyst. Some of the samples were obtained from PE mixed with other types, such as Polystyrene (PS), Polypropylene (PP), Polyethylene Terephthalate (PET), and Others. Char properties, such as moisture, ash, volatile matter, and fixed carbon contents, are revealed from the proximate analysis, whereas calorific values were measured with a bomb calorimeter. Briquettes are made by mixing 4 g of char with 0.5 - 1 g binder. Briquettes are hollow cylinders with an outer and inner diameter of around 1.75 cm and 0.25 cm, respectively. Combustion is carried out in a furnace with wall temperatures of about 230°C and a constant air velocity of 0.7 m/s. Five out of 13 char briquettes are not feasible because they melt during combustion. Briquettes made from 100% PE wastes burn in substantially shorter duration than those from mixed plastic wastes. Char #1 and #5 are excellent due to their highest energy release, whereas #10 show the worst performance.

  8. Effective Diffusion Coefficients in Coal Chars

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Jensen, Anker

    2001-01-01

    Knowledge of effective diffusion coefficients in char particles is important when interpreting experimental reactivity measurements and modeling char combustion or NO and N2O reduction. In this work, NO and N2O reaction with a bituminous coal char was studied in a fixed-bed quartz glass reactor....... The experimental results were compared with theoretical values calculated from the mean pore radius and the cross-linked pore model. The method of mean pore radius underestimated the effective diffusion coefficient more than an order of magnitude. Using the cross-linked pore model, the bimodal pore size...

  9. Reactivities of Shenfu Chars Toward Gasification with Carbon Dioxide

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jia-wei; WEI Xian-yong; ZONG Zhi-min; WANG Tao-xia; XIE Rui-lun; DING Ming-jie; CAI Ke-ying; HUANG Yao-guo; GAO Jin-sheng; WU You-qing

    2007-01-01

    Five Shenfu char samples were prepared from Shenfu raw coal at different temperatures (950, 1100, 1200, 1300 and 1400 ℃) using a muffle furnace. Demineralization of the char samples was performed by treating them with 10% nitric acid for 10 min in a CEM Discover microwave reactor. The gasification of the chars, and corresponding demineralized chars, in a carbon dioxide (CO2) atmosphere was conducted in a Netzsch STA 409C131F temperature-programmed thermogravimetry apparatus. The effects of charring temperature and demineralization on the gasification reactivity of chars were systematically investigated. The results show that a char formed at a lower temperature is more reactive except for demineralized char formed at 1100 ℃, which is less reactive than char formed at 1200 ℃. Demineralization decreases the char reactivities toward gasification with CO2 to a small extent.

  10. Where have all the females gone? Male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) in alpine lakes

    Science.gov (United States)

    Žibrat, U.; Brancelj, A.

    2009-04-01

    In populations with both males and females sex-ratio is one of the driving forces of population dynamics. It influences fecundity, inbreeding and social interactions. Sex-ratio is affected by several biotic and abiotic factors, either by selective killing of one sex or by inducing migrations. In alpine lakes of Triglav National Park, Slovenia, an extremely male biased sex-ratio in Arctodiaptomus alpinus (Imhof, 1885) was regularly observed since 1992. We analysed population dynamics and sex-ratio of A. alpinus in three alpine lakes (Jezero v Ledvicah, Rjavo jezero and Zgornje Kriško jezero) from Triglav National Park in Slovenia. In addition to seasonal dynamics we also researched long-term changes in sex-ratio (in a period of 11 years from autumn samples) as a result of increased air-temperature, and zooplankton diurnal vertical migrations. Adults of both sexes were found to appear at the same time in the water collumn with males prevailing throughout the season. A similar trend was found in copepodites CV. The percent of adult females began increasing in late summer, when there were no more copepodites and recrutation from copepodites CV to adults stopped, while male mortality increased. All cohorts of A. alpinus were found to perform diurnal vertical migrations. Both adult and CV females remained close to the bottom during the day and migrated vertically during the night. Results of the long-term study show no changes in sex-ratio in autumn.

  11. Modeling pyrolysis of charring material in fire

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A modified model of pyrolysis for charring materials in fire has been proposed in this note. In this model some special factors which show the effect on pyrolysis are considered, i.e. heat loss by convection and radiation caused by surface temperature rise and shrinkage of char surface are considered. Experimental device is designed specially for validating the reliability of the model. Effects of density of materials and heat radiation on pyrolysis of materials have also been investigated.

  12. Changes in char reactivity due to char-oxygen and char-steam reactions using Victorian brown coal in a fixed-bed reactor

    Institute of Scientific and Technical Information of China (English)

    Shu Zhang; Yonggang Luo; Chunzhu Li; Yonggang Wang

    2015-01-01

    This study was to examine the influence of reactions of char–O2 and char–steam on the char reactivity evolution. A newly-designed fixed-bed reactor was used to conduct gasification experiments using Victorian brown coal at 800 °C. The chars prepared from the gasification experiments were then collected and subjected to reactivity characterisation (ex-situ reactivity) using TGA (thermogravimetric analyser) in air. The results indicate that the char reactivity from TGA was generally high when the char experienced intensive gasification reactions in 0.3%O2 in the fixed-bed reactor. The addition of steam into the gasification not only enhanced the char conversion sig-nificantly but also reduced the char reactivity dramatical y. The curve shapes of the char reactivity with involve-ment of steam were very different from that with O2 gasification, implying the importance of gasifying agents to char properties.

  13. Comparison of kinetic models for isothermal CO2 gasification of coal char-biomass char blended char

    Science.gov (United States)

    Zuo, Hai-bin; Geng, Wei-wei; Zhang, Jian-liang; Wang, Guang-wei

    2015-04-01

    This study investigated the isothermal gasification reactivity of biomass char (BC) and coal char (CC) blended at mass ratios of 1:3, 1:1, and 3:1 via isothermal thermogravimetric analysis (TGA) at 900, 950, and 1000°C under CO2. With an increase in BC blending ratio, there were an increase in gasification rate and a shortening of gasification time. This could be attributed to the high specific surface area of BC and the high uniformity of carbon structures in CC when compared to those in BC. Three representative gas-solid kinetic models, namely, the volumetric model (VM), grain model (GM), and random pore model (RPM), were applied to describe the reaction behavior of the char. Among them, the RPM model was considered the best model to describe the reactivity of the char gasification reaction. The activation energy of BC and CC isothermal gasification as determined using the RPM model was found to be 126.7 kJ/mol and 210.2 kJ/mol, respectively. The activation energy was minimum (123.1 kJ/mol) for the BC blending ratio of 75%. Synergistic effect manifested at all mass ratios of the blended char, which increased with the gasification temperature.

  14. Char characterisation and its application in a coal burnout mode

    Energy Technology Data Exchange (ETDEWEB)

    Michael Cloke; Tao Wu; Richelieu Barranco; Ed Lester [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering, Coal Technology Research Group

    2003-10-01

    In this study, char image analysis techniques have been employed to investigate the morphology of chars obtained from a Drop-Tube furnace. Char image analysis results have been incorporated as inputs to a char burnout model based on Hurt's CBK model. It has been observed that the char combustion rate was strongly affected by char structural parameters and the inclusion of char morphology has led to a better prediction of char burnout. It has also been suggested by the model that the inclusion of ash inhibition overestimates the resistance attributed by ash film and the consideration of ash film resistance should be undertaken in a different way to give a better prediction at the later stages of char combustion. 12 refs., 13 figs., 5 tabs.

  15. NO Reduction over Biomass and Coal Char during Simultaneous Combustion

    DEFF Research Database (Denmark)

    Zhao, Ke; Glarborg, Peter; Jensen, Anker Degn

    2013-01-01

    . The straw and bark chars showed higher reactivity, about a factor of 4–5, than bituminous char at 850 °C. The difference in reactivity between biomass char and bituminous char decreased with increasing reaction temperature. The reaction rate expressions for NO reduction during simultaneous combustion......This paper reports an experimental study of NO reduction over chars of straw, bark, bituminous coal, and lignite. The experiments were performed in a fixed bed reactor in the temperature range 850–1150 °C. The chars were generated by in situ pyrolysis at the reaction temperature to minimize further...... thermal deactivation. The rates of NO reduction over char were studied by char combustion experiments and O2-free experiments respectively. Two simple models were applied to interpret the data from the char combustion experiments. One model assumed that combustion and NO release take place uniformly...

  16. Use of cover habitat by bull trout Salvelinus confluentus and lake trout Salvelinus namaycush in a laboratory environment

    Science.gov (United States)

    Meeuwig, Michael H.; Guy, Christopher S.; Fredenberg, Wade A.

    2011-01-01

    Lacustrine-adfluvial bull trout, Salvelinus confluentus, migrate from spawning and rearing streams to lacustrine environments as early as age 0. Within lacustrine environments, cover habitat pro- vides refuge from potential predators and is a resource that is competed for if limiting. Competitive inter- actions between bull trout and other species could result in bull trout being displaced from cover habitat, and bull trout may lack evolutionary adaptations to compete with introduced species, such as lake trout, Salvelinus namaycush. A laboratory experiment was performed to examine habitat use and interactions for cover by juvenile (i.e., bull trout and lake trout. Differences were observed between bull trout and lake trout in the proportion of time using cover (F1,22.6=20.08, Pbull trout using cover and bottom habitats more than lake trout. Habitat selection ratios indicated that bull trout avoided water column habitat in the presence of lake trout and that lake trout avoided bottom habitat. Intraspecific and interspecific agonistic interactions were infrequent, but approximately 10 times greater for intraspecific inter- actions between lake trout. Results from this study provide little evidence that juvenile bull trout and lake trout compete for cover, and that species-specific differences in habitat use and selection likely result in habitat partitioning between these species.

  17. Lake trout (Salvelinus namaycush) suppression for bull trout (Salvelinus confluentus) recovery in Flathead Lake, Montana, North America

    Science.gov (United States)

    Hansen, Michael J.; Hansen, Barry S; Beauchamp, David A.

    2016-01-01

    Non-native lake trout Salvelinus namaycush displaced native bull trout Salvelinus confluentus in Flathead Lake, Montana, USA, after 1984, when Mysis diluviana became abundant following its introduction in upstream lakes in 1968–1976. We developed a simulation model to determine the fishing mortality rate on lake trout that would enable bull trout recovery. Model simulations indicated that suppression of adult lake trout by 75% from current abundance would reduce predation on bull trout by 90%. Current removals of lake trout through incentivized fishing contests has not been sufficient to suppress lake trout abundance estimated by mark-recapture or indexed by stratified-random gill netting. In contrast, size structure, body condition, mortality, and maturity are changing consistent with a density-dependent reduction in lake trout abundance. Population modeling indicated total fishing effort would need to increase 3-fold to reduce adult lake trout population density by 75%. We conclude that increased fishing effort would suppress lake trout population density and predation on juvenile bull trout, and thereby enable higher abundance of adult bull trout in Flathead Lake and its tributaries.

  18. Potential Sources of High Frequency and Biphonic Vocalization in the Dhole (Cuon alpinus.

    Directory of Open Access Journals (Sweden)

    Roland Frey

    Full Text Available Biphonation, i.e. two independent fundamental frequencies in a call spectrum, is a prominent feature of vocal activity in dog-like canids. Dog-like canids can produce a low (f0 and a high (g0 fundamental frequency simultaneously. In contrast, fox-like canids are only capable of producing the low fundamental frequency (f0. Using a comparative anatomical approach for revealing macroscopic structures potentially responsible for canid biphonation, we investigated the vocal anatomy for 4 (1 male, 3 female captive dholes (Cuon alpinus and for 2 (1 male, 1 female wild red fox (Vulpes vulpes. In addition, we analyzed the acoustic structure of vocalizations in the same dholes that served postmortem as specimens for the anatomical investigation. All study dholes produced both high-frequency and biphonic calls. The anatomical reconstructions revealed that the vocal morphologies of the dhole are very similar to those of the red fox. These results suggest that the high-frequency and biphonic calls in dog-like canids can be produced without specific anatomical adaptations of the sound-producing structures. We discuss possible production modes for the high-frequency and biphonic calls involving laryngeal and nasal structures.

  19. Evaluation of char combustion models: measurement and analysis of variability in char particle size and density

    Energy Technology Data Exchange (ETDEWEB)

    Daniel J. Maloney; Esmail R. Monazam; Kent H. Casleton; Christopher R. Shaddix

    2008-08-01

    Char samples representing a range of combustion conditions and extents of burnout were obtained from a well-characterized laminar flow combustion experiment. Individual particles from the parent coal and char samples were characterized to determine distributions in particle volume, mass, and density at different extent of burnout. The data were then compared with predictions from a comprehensive char combustion model referred to as the char burnout kinetics model (CBK). The data clearly reflect the particle- to-particle heterogeneity of the parent coal and show a significant broadening in the size and density distributions of the chars resulting from both devolatilization and combustion. Data for chars prepared in a lower oxygen content environment (6% oxygen by vol.) are consistent with zone II type combustion behavior where most of the combustion is occurring near the particle surface. At higher oxygen contents (12% by vol.), the data show indications of more burning occurring in the particle interior. The CBK model does a good job of predicting the general nature of the development of size and density distributions during burning but the input distribution of particle size and density is critical to obtaining good predictions. A significant reduction in particle size was observed to occur as a result of devolatilization. For comprehensive combustion models to provide accurate predictions, this size reduction phenomenon needs to be included in devolatilization models so that representative char distributions are carried through the calculations.

  20. Kinetic Analysis of Char Thermal Deactivation

    DEFF Research Database (Denmark)

    Zolin, Alfredo; Jensen, Anker; Dam-Johansen, Kim

    2001-01-01

    The thermal deactivation of several fuels was investigated by measuring the reactivity, of chars prepared in a thermogravimetric analyzer (TGA) apparatus at well-defined conditions in the temperature range 973-1673 K. Four coals, Blair Athol from Australia, Cerrejon from Colombia. Illinois no. 6....... Leached straw deactivates significantly, but maintains at any heat-treatment temperature a higher reactivity than the other chars. The inertinite-rich coal Blair Athol is more resistant to deactivation than two vitrinite-rich coals of the same ASTM rank, Cerrejon and Illinois no. 6. Cerrejon and Illinois...

  1. Active sites in char gasification: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Wojtowicz, M.; Lilly, W.D.; Perkins, M.T.; Hradil, G.; Calo, J.M.; Suuberg, E.M.

    1987-09-01

    Among the key variables in the design of gasifiers and combustors is the reactivity of the chars which must be gasified or combusted. Significant loss of unburned char is unacceptable in virtually any process; the provision of sufficient residence time for complete conversion is essential. A very wide range of reactivities are observed, depending upon the nature of the char in a process. The current work focuses on furthering the understanding of gasification reactivities of chars. It has been well established that the reactivity of char to gasification generally depends upon three principal factors: (1) the concentration of ''active sites'' in the char; (2) mass transfer within the char; and (3) the type and concentration of catalytic impurities in the char. The present study primarily addresses the first factor. The subject of this research is the origin, nature, and fate of active sites in chars derived from parent hydrocarbons with coal-like structure. The nature and number of the active sites and their reactivity towards oxygen are examined in ''model'' chars derived from phenol-formaldehyde type resins. How the active sites are lost by the process of thermal annealing during heat treatment of chars are studied, and actual rate for the annealing process is derived. Since intrinsic char reactivities are of primary interest in the present study, a fair amount of attention was given to the model char synthesis and handling so that the effect of catalytic impurities and oxygen-containing functional groups in the chemical structure of the material were minimized, if not completely eliminated. The project would not be considered complete without comparing characteristic features of synthetic chars with kinetic behavior exhibited by natural chars, including coal chars.

  2. Flume length and post-exercise impingement affect anaerobic metabolism in brook charr Salvelinus fontinalis.

    Science.gov (United States)

    Tudorache, C; O'Keefe, R A; Benfey, T J

    2010-02-01

    The effect of flume length and impingement time on post-exercise lactate concentrations in brook charr Salvelinus fontinalis were examined. Swimming in longer flumes increased lactate concentrations, as does impingement after swimming in short flumes.

  3. Coal char oxidation kinetics in air medium

    Directory of Open Access Journals (Sweden)

    Korotkikh Alexander G.

    2017-01-01

    Full Text Available Study of oxidation kinetics for three types of coal char with different carbon content in air is presented. The coal char powders of anthracite, bituminous T-grade coal and 2B-grade lignite with particle size less than 80 μm were tested. The coal char oxidation was researched by isothermal method via simultaneous TG-DSC analyzer Netzsch STA 449 Jupiter F3 in the temperature range of 1000–1200 °C. Measurements were carried out at ambient pressure. Volumetric flow rate of oxidizing medium into analyser chamber was 250 ml/min. Flow consisted of air and argon with volumetric ratio 24/1. Carbon average rate of oxidation reaction at each temperature were defined based on experimental results. Kinetic constants (the frequency factor and activation energy were defined for Arrhenius equation modified with three submodels: volumetric model, shrinking core model and random pore model. The activation energy values for anthracite are 1,6-1,7 times higher than for chars of bituminous coal and lignite.

  4. Modeling sublimation of a charring ablator

    Science.gov (United States)

    Balhoff, J. F.; Pike, R. W.

    1973-01-01

    The Hertz-Knudsen analysis is shown to accurately predict the sublimation rate from a charring ablator. Porosity is shown to have a significant effect on the surface temperature. The predominant carbon species found in the vapor is C3, which agrees well with the results of previous investigations.

  5. Phosphorus recovery from sewage sludge char ash

    NARCIS (Netherlands)

    Atienza-Martinez, M.; Gea, G.; Arauzo, J.; Kersten, S.R.A.; Kootstra, A.M.J.

    2014-01-01

    Phosphorus was recovered from the ash obtained after combustion at different temperatures (600 °C, 750 °C and 900 °C) and after gasification (at 820 °C using a mixture of air and steam as fluidising agent) of char from sewage sludge fast pyrolysis carried out at 530 °C. Depending on the leaching con

  6. Plecotus alpinus: primi dati sull'utilizzo dell'habitat

    Directory of Open Access Journals (Sweden)

    Adriano Martinoli

    2003-10-01

    Full Text Available Negli ultimi anni il numero delle specie di Chirotteri note per l?Europa si è accresciuto, grazie all?uso di tecniche di genetica molecolare, ed in particolare il genere Plecotus è quello che ha registrato maggiori cambiamenti con la descrizione di tre nuove specie: Plecotus kolombatovici, P. alpinus e P. sardus (Kiefer & Veith, 2001; Mucedda et al., 2002. Alla luce di queste nuove scoperte, la distribuzione geografica e le preferenze dell?habitat delle due specie ?storiche? di Orecchione in Europa, Plecotus auritus e P. austriacus, dovrebbero essere riviste: in questo contesto si inserisce l?indagine svolta nel Parco Regionale Campo dei Fiori (in provincia di Varese sulla prima colonia riproduttiva di Plecotus alpinus segnalata per la regione Lombardia. Al fine di valutare le preferenze nell?uso dell?habitat e le direttrici di spostamento preferenziali di tale specie, nonché per l?identificazione di siti di rilevanza per l?allevamento della prole, si è fatto ricorso a tecniche di radiolocalizzazione, subordinate alla cattura a vivo degli animali. Le catture si sono svolte nel periodo 15 giugno ? 15 agosto del 2002 e del 2003. Per ogni individuo catturato, oltre alla determinazione di specie, sesso e classe d?età, sono stati rilevati i dati biometrici e prelevati campioni di tessuto destinati all?analisi genetica. Sono state inoltre registrate le emissioni ultrasonore. Durante il primo anno di indagine sono state seguite mediante radiolocalizzazione 5 femmine adulte (4 allattanti ed una non allattante e due femmine subadulte, mentre durante il secondo anno sono state munite di radiocollare 6 femmine adulte (5 allattanti ed una non allattante ed una femmina subadulta. Ai pipistrelli è stato applicato un emettitore radio (tag modello LB-2, Holohil Systems Ltd, Ontario, Canada. Il segnale emesso è stato ricevuto in campo mediante l?utilizzo di radio (Wildlife

  7. Is isolation by adaptation driving genetic divergence among proximate Dolly Varden char populations?

    Science.gov (United States)

    Bond, Morgan H; Crane, Penelope A; Larson, Wesley A; Quinn, Tom P

    2014-06-01

    Numerous studies of population genetics in salmonids and other anadromous fishes have revealed that population structure is generally organized into geographic hierarchies (isolation by distance), but significant structure can exist in proximate populations due to varying selective pressures (isolation by adaptation). In Chignik Lakes, Alaska, anadromous Dolly Varden char (Salvelinus malma) spawn in nearly all accessible streams throughout the watershed, including those draining directly to an estuary, Chignik Lagoon, into larger rivers, and into lakes. Collections of Dolly Varden fry from 13 streams throughout the system revealed low levels of population structure among streams emptying into freshwater. However, much stronger genetic differentiation was detected between streams emptying into freshwater and streams flowing directly into estuarine environments. This fine-scale reproductive isolation without any physical barriers to migration is likely driven by differences in selection pressures across freshwater and estuarine environments. Estuary tributaries had fewer larger, older juveniles, suggesting an alternative life history of smolting and migration to the marine environment at a much smaller size than occurs in the other populations. Therefore, genetic data were consistent with a scenario where isolation by adaptation occurs between populations of Dolly Varden in the study system, and ecological data suggest that this isolation may partially be a result of a novel Dolly Varden life history of seawater tolerance at a smaller size than previously recognized.

  8. Sprint swimming performance of wild bull trout (Salvelinus confluentus)

    Science.gov (United States)

    Mesa, M.G.; Phelps, J.; Weiland, L.K.

    2008-01-01

    We conducted laboratory experiments to determine the sprint swimming performance of wild juvenile and adult bull trout Salvelinus confluentus. Sprint swimming speeds were estimated using high-speed digital video analysis. Thirty two bull trout were tested in sizes ranging from about 10 to 31 cm. Of these, 14 fish showed at least one motivated, vigorous sprint. When plotted as a function of time, velocity of fish increased rapidly with the relation linear or slightly curvilinear. Their maximum velocity, or Vmax, ranged from 1.3 to 2.3 m/s, was usually achieved within 0.8 to 1.0 s, and was independent of fish size. Distances covered during these sprints ranged from 1.4 to 2.4 m. Our estimates of the sprint swimming performance are the first reported for this species and may be useful for producing or modifying fish passage structures that allow safe and effective passage of fish without overly exhausting them. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  9. Combustion char morphology related to combustion temperature and coal petrography

    Energy Technology Data Exchange (ETDEWEB)

    Rosenberg, P.; Petersen, H.I.; Thomsen, E. [Geological Survey of Denmark, Copenhagen (Denmark)

    1996-07-01

    Chars produced from different reactors were found to lack consistency of morphological charactersitics. Therefore, the morphology of chars sampled from various laboratory-scale reactors operating at temperatures from 800 to {gt} 1400{degree}C, together with chars collected directly in the flame zone in a full-scale pulverised fuel combustion experiment, was examined. A coal and coal blend dominated by vitrinite-rich microlithotypes together with four coals dominated by inertinite-rich microlithotypes were used to produce the combustion chars. Char samples produced at temperatures above {approximately} 1300{degree}C have a morphotype composition very similar to the composition of the full-scale char samples, whereas the morphotype compositions of those produced at {approximately} 1550{degree}C or lower are significantly different. Correlation between coal petrography and char morphology and determination of char reactivity should thus be attempted only using chars produced at temperatures comparable with those for the intended use of the coal. A clear distinction between the high-temperature char samples (burnout 50-60wt% daf) emerges which is related mainly to the parent coal petrography and probably secondarily to the rank. Vitrite, clarite and vitrinertie V may be correlated with the porous tenuisphere and crassisphere morphotypes, whereas inertite, durite, vitrinertite I, duroclarite and charodurite may be correlated with the crassinetwork-mixed-network-mixed morphotype group. 29 refs., 7 figs., 7 tabs.

  10. Addressing catch mechanisms in gillnets improves modeling of selectivity and estimates of mortality rates: a case study using survey data on an endangered stock of Arctic char

    DEFF Research Database (Denmark)

    Jonsson, T.; Setzer, M.; Pope, John George;

    2013-01-01

    Estimation of fish stock size distributions from survey data requires knowledge about gear selectivity. However, selectivity models rest on assumptions that seldom are analyzed. Departures from these can lead to misinterpretations and biased management recommendations. Here, we use survey data...... on great Arctic char (Salvelinus umbla) to analyze how correcting for entanglement of fish and nonisometric growth might improve estimates of selectivity curves, and subsequently estimates of size distribution and age-specific mortality. Initial selectivity curves, using the entire data set, were wide...... and asymmetric, with poor model fits. Removing potentially nonmeshed fish had the greatest positive effect on model fit, resulting in much narrower and less asymmetric selection curves, while attempting to take nonisometric growth into account, by using girth rather than length, improved model fit...

  11. Development, Verification and Validation of Enclosure Radiation Capabilities in the CHarring Ablator Response (CHAR) Code

    Science.gov (United States)

    Salazar, Giovanni; Droba, Justin C.; Oliver, Brandon; Amar, Adam J.

    2016-01-01

    With the recent development of multi-dimensional thermal protection system (TPS) material response codes including the capabilities to account for radiative heating is a requirement. This paper presents the recent efforts to implement such capabilities in the CHarring Ablator Response (CHAR) code developed at NASA's Johnson Space Center. This work also describes the different numerical methods implemented in the code to compute view factors for radiation problems involving multiple surfaces. Furthermore, verification and validation of the code's radiation capabilities are demonstrated by comparing solutions to analytical results, to other codes, and to radiant test data.

  12. Kinetics and Mechanisms of NO(x) - Char Reduction.

    Energy Technology Data Exchange (ETDEWEB)

    Suurerg, E.M.; Lilly, W.D.; Aarna, I.

    1997-12-31

    Most industrially important carbons are produced from naturally occurring materials such as coal, oil, peat or wood by some form of thermal process. Chars are obtained from those natural materials as a residue after removal of the volatile matter. Chars (prepared from coal or other organic precursors) are non-graphitizable carbons, meaning that they cannot be transformed into graphitic carbon. Chars are comprised of elementary crystallites in parallel layers which are randomly oriented with respect to each other and are crosslinked together through weak bonds. Voids between crystallites determine the porosity of the char, and this plays an important role in char gasification behavior. Chars usually contain a pore size distribution, in which the larger macro- and mesopores play an important role in transport of reactants into the much smaller micropores, in which most gasification and combustion take place. Therefore, the effectiveness of micropores in gasification depends heavily on the numbers of meso- and macropores.

  13. Structural and Compositional Transformations of Biomass Chars during Fast Pyrolysis

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Steibel, Markus; Spliethoff, Hartmut

    In this work the physical and chemical transformations of biomass chars during fast pyrolysis, considered as a 2nd stage of combustion, has been investigated. Seven biomasses containing different amount of ash and organic components were reacted at up to 1673 K with high heating rates in a wire......-mesh reactor and the resulting chars were retrieved. In order to obtain information on the structural and compositional transformations of the biomass chars, samples were subjected to elemental analysis, scanning electron microcopy with EDX and Raman spectrometry. The results show that there are significant...... changes in both the organic and inorganic constituents of the chars.Under high heating rates (> 100 K/s) char particles underwent different types of melting and pores of different size were developed in dependency on the temperature and biomass composition. The Si-rich rice husks char did not show any...

  14. Coal and char studies by advanced EMR techniques

    Energy Technology Data Exchange (ETDEWEB)

    Belford, R.L.; Clarkson, R.B.; Odintsov, B.M.

    1999-03-31

    Advanced magnetic resonance (EMR) methods are used to examine properties of coals, chars, and molecular species related to constituents of coal. During this grant period, further progress was made on proton NMR and low-frequency dynamic nuclear polarization (DNP) to examine the interaction between fluids such as water and the surface of suspended char particles. Effects of char particle size and type on water nuclear spin relaxation, T2, were measured and modeled.

  15. Char porosity characterisation by scanning electron microscopy and image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, H.S.; Rosenberg, P.; Petersen, H.I.; Soerensen, L.H. [Danfoss A/S, Nordborg (Denmark)

    2000-09-01

    No significant change in either the morphotype composition or the macroporosity (pores {gt}5 {mu}m) in the 0-30 wt.% char burnout interval were revealed by reflected light microscopy or image analysis. Two high temperature char series from a Tertiary South American coal (C1) and a Permian Gondwana coal (C2) were therefore examined by scanning electron microscopy to provide information on the combustion process up to {approximately} 60 wt% char burnout. This study documents a significant mesopore ({approximately} 0.1-5 {mu}m) development on the fused chars in the burnout interval studied. A method to quantify the size and amount of the mesopores is described and both the parameters increased with increasing char burnout. Above a char burnout of {approximately} 30 wt% an increase in macroporosity was detected and ascribed to coalescence of mesopores to form large pores. Although the measurement of mesoporosity is restricted to fused chars, i.e. pores in fragments and the char morphotypes inertoid, fusinoid and solid could not be measured, the consideration of mesoporosity seems to be fundamental in understanding, evaluating and modelling combustion processes in the char burnout interval studied. 7 refs., 9 figs., 4 tabs.

  16. Multiscale hydrogeomorphic influences on bull trout (Salvelinus confluentus) spawning habitat

    Science.gov (United States)

    Bean, Jared R; Wilcox, Andrew C.; Woessner, William W.; Muhlfeld, Clint C.

    2015-01-01

    We investigated multiscale hydrogeomorphic influences on the distribution and abundance of bull trout (Salvelinus confluentus) spawning in snowmelt-dominated streams of the upper Flathead River basin, northwestern Montana. Within our study reaches, bull trout tended to spawn in the finest available gravel substrates. Analysis of the mobility of these substrates, based on one-dimensional hydraulic modeling and calculation of dimensionless shear stresses, indicated that bed materials in spawning reaches would be mobilized at moderate (i.e., 2-year recurrence interval) high-flow conditions, although the asynchronous timing of the fall–winter egg incubation period and typical late spring – early summer snowmelt high flows in our study area may limit susceptibility to redd scour under current hydrologic regimes. Redd occurrence also tended to be associated with concave-up bedforms (pool tailouts) with downwelling intragravel flows. Streambed temperatures tracked stream water diurnal temperature cycles to a depth of at least 25 cm, averaging 6.1–8.1 °C in different study reaches during the spawning period. Ground water provided thermal moderation of stream water for several high-density spawning reaches. Bull trout redds were more frequent in unconfined alluvial valley reaches (8.5 versus 5.0 redds·km−1 in confined valley reaches), which were strongly influenced by hyporheic and groundwater – stream water exchange. A considerable proportion of redds were patchily distributed in confined valley reaches, however, emphasizing the influence of local physical conditions in supporting bull trout spawning habitat. Moreover, narrowing or “bounding” of these alluvial valley segments did not appear to be important. Our results suggest that geomorphic, thermal, and hydrological factors influence bull trout spawning occurrence at multiple spatial scales.

  17. Production of activated carbon from TCR char

    Science.gov (United States)

    Stenzel, Fabian; Heberlein, Markus; Klinner, Tobias; Hornung, Andreas

    2016-04-01

    The utilization of char for adsorptive purposes is known since the 18th century. At that time the char was made of wood or bones and used for decoloration of fluids. In the 20th century the production of activated carbon in an industrial scale was started. The today's raw materials for activated carbon production are hard coal, peat, wood or coconut shells. All these materials entail costs especially the latter. Thus, the utilization of carbon rich residues (biomass) is an interesting economic opportunity because it is available for no costs or even can create income. The char is produced by thermo-catalytic reforming (TCR®). This process is a combination of an intermediate pyrolysis and subsequently a reforming step. During the pyrolysis step the material is decomposed in a vapor and a solid carbon enriched phase. In the second step the vapor and the solid phase get in an intensive contact and the quality of both materials is improved via the reforming process. Subsequently, the condensables are precipitated from the vapor phase and a permanent gas as well as oil is obtained. Both are suitable for heat and power production which is a clear advantage of the TCR® process. The obtained biochar from the TCR® process has special properties. This material has a very low hydrogen and oxygen content. Its stability is comparable to hard coal or anthracite. Therefore it consists almost only of carbon and ash. The latter depends from input material. Furthermore the surface structure and area can be influenced during the reforming step. Depending from temperature and residence time the number of micro pores and the surface area can be increased. Preliminary investigations with methylene blue solution have shown that a TCR® char made of digestate from anaerobic digestion has adsorptive properties. The decoloration of the solution was achieved. A further influencing factor of the adsorption performance is the particle size. Based on the results of the preliminary tests a

  18. Comparison of steam-gasification characteristics of coal char and petroleum coke char in drop tube furnace

    Institute of Scientific and Technical Information of China (English)

    Lu Ding; Zhijie Zhou; Wei Huo; Guangsuo Yu

    2015-01-01

    The steam-gasification reaction characteristics of coal and petroleum coke (PC) were studied in the drop tube fur-nace (DTF). The effects of various factors such as types of carbonaceous material, gasification temperature (1100–1400 °C) and mass ratio of steam to char (0.4:1, 0.6:1 and 1:1 separately) on gasification gas or solid products were investigated. The results showed that for al carbonaceous materials studied, H2 content exhibited the larg-est part of gasification gaseous products and CH4 had the smal est part. For the two petroleum cokes, CO2 content was higher than CO, which was similar to Zun-yi char. When the steam/char ratio was constant, the carbon con-version of both Shen-fu and PC chars increased with increasing temperature. When the gasification temperature was constant, the carbon conversions of al char samples increased with increasing steam/char ratio. For al the steam/char ratios, compared to water gas shift reaction, char-H2O and char-CO2 reaction were further from the thermodynamic equilibrium due to a much lower char gasification rate than that of water gas shift reaction rate. Therefore, kinetic effects may play a more important role in a char gasification step than thermodynamic ef-fects when the gasification reaction of char was held in DTF. The calculating method for the equilibrium shift in this study wil be a worth reference for analysis of the gaseous components in industrial gasifier. The reactivity of residual cokes decreased and the crystal layer (L002/d002) numbers of residual cokes increased with increasing gasification temperature. Therefore, L002/d002, the carbon crystallite structure parameter, can be used to evaluate the reactivity of residual cokes.

  19. Effets du conditionnement en jours longs à la fin du cycle reproducteur sur la période d'ovulation et sur les sécrétions gonadotropes chez l'omble chevalier (Salvelinus alpinus

    Directory of Open Access Journals (Sweden)

    GILLET C.

    1998-07-01

    Full Text Available Les ombles chevaliers originaires du Léman se reproduisent à la fin de l'automne. En élevage, il est intéressant de retarder de quelques mois la période des ovulations car ce poisson a besoin d'une température inférieure à 6°C pendant l'ovulation. Il est plus facile de fournir une eau à cette température aux géniteurs retardés qui ovulent en hiver qu'à ceux qui ovulent naturellement en automne. Le conditionnement des ombles chevaliers en jours longs (17L-7N pendant l'automne permet de retarder de plusieurs mois la période des ovulations. Cette méthode a l'inconvénient de provoquer un étalement des ovulations sur plus de 3 mois. Le reconditionnement des géniteurs en jours courts en décembre supprime ce problème. L'efficacité du traitement en jours longs ne semble pas dépendre de la durée de son application pourvu que celle-ci dépasse 1,5 mois. Chez les femelles conditionnées en jours longs en automne et en hiver, les concentrations en gonadotropine plasmatique (GTH II sont très faibles. Le niveau de la GTH II plasmatique augmente trois semaines après un transfert en jours courts en janvier. Les concentrations de la GTH II plasmatique au cours de l'ovulation sont significativement plus faibles chez les femelles conditionnées en jours longs en janvier que chez les animaux reconditionnés en jours courts. A ce stade du cycle reproducteur, la GTH I plasmatique reste toujours à un niveau très faible, quel que soit le régime photopériodique. La pose d'implant de mélatonine chez les poissons ne modifie pas les sécrétions gonadotropes en jours longs comme en jours courts. La réceptivité hypophysaire des femelles à une stimulation de la sécrétion gonadotrope par une injection de GnRH n'est pas modifiée par le conditionnement des poissons en jours longs. Aucun effet du pimozide sur la sécrétion de la GTH II n'a pu être mis en évidence chez les géniteurs conditionnés en jours longs. Ces résultats permettent de supposer que l'action inhibitrice des jours longs sur l'ovulation n'est pas la conséquence d'un blocage de type dopaminergique de la sécrétion gonadotrope. Ce type d'inhibition mettrait en oeuvre des mécanismes différents de ceux impliqués dans le blocage de l'ovulation par des températures élevées. L'effet inhibiteur des jours longs à ce stade du cycle reproducteur passe par une diminution de la sécrétion gonadotrope de la GTH II, probablement en relation avec des modifications du contrôle hypothalamique de la sécrétion de la gonadotropine hypophysaire (GTH II.

  20. Corrosive components of nutshells and their chars

    Directory of Open Access Journals (Sweden)

    Karczewski Mateusz

    2016-01-01

    Full Text Available Biomass combustion stands among various technologies pointed at fossil fuels consumption decrease. Biomass can be found in very diversified sources spread more evenly across the globe, can be burned with use of traditional combustion solutions and is more CO2 neutral in combustion than their fossil fuel counterparts. On the other hand biomass has several problems with composition that despite its potential diversity. Problem of excess moisture can be already solved by material selection or by preliminary pyrolysis. The main problem concerns however biomass ash composition. Biomass ashes are more prone to have higher quantities of potentially corrosive components than their coal counterparts. The example of such constituents are alkali metals, sulphur and chlorine. Ash basic composition is also important due to various ash properties like its melting temperature and slagging or fouling tendencies. To address the problem, several indices for fast properties prediction and earlier problem identification can be appointed. This work concentrates on ash quality evaluation for potentially attractive biomass fuel from nutshell materials and their corresponding char obtained by pyrolysis in 300, 450 and 550 °C. Pistachio and hazelnut shells with their chars will be analysed for corrosive compounds and their potential influence on combustion process.

  1. STUDY OF ACTIVATION OF COAL CHAR

    Energy Technology Data Exchange (ETDEWEB)

    E.M. Suuberg; I. Kulaots; I Aarna; M. Callejo; A. Hsu

    2003-12-31

    This is the final report on a project whose aim is to explore in a fundamental manner the factors that influence the development of porosity in coal chars during the process of activation. It is known that choices of starting coal, activating agent and conditions can strongly influence the nature of an activated carbon produced from a coal. This project has been concerned mainly with the process of physical activation, which in fact involves the gasification of a char produced from a coal by oxidizing gases. This is of interest for two reasons. One is that there is commercial interest in production of activated carbons from coal, and therefore, in the conditions that can best be used in producing these materials. Much is already known about this, but there is a great deal that is in the realm of ''trade secret'' or just ''industry lore''. The second reason for interest in these processes is that they shed light on how porosity develops during any gasification process involving oxidizing gases. This has implications for understanding the kinetics and the role that ''surface area'' may play in determining kinetics. In earlier reports from this project, several conclusions had been reached upon which the present results rest. There is an often-cited difference in use of nitrogen and carbon dioxide as molecular probes of carbon porosity when using vapor adsorption techniques. Carbon dioxide is often ''preferred'' since it is argued that it offers greater access to fine microporosity, due to the higher temperature of carbon dioxide as opposed to nitrogen measurements. The early phases of this work revealed that the extreme differences are observed only in chars which are not much activated, and that by a few weight percent burnoff, the difference was negligible, provided a consistent theoretical equation was used in calculating uptake or ''surface area''. In another phase

  2. Stable carbon isotope changes during artificial charring of propagules

    NARCIS (Netherlands)

    Poole, I.J.; Braadbaart, F.; Boon, J.J.; Bergen, P.F. van

    2002-01-01

    Charred organic remains are ubiquitous in the archaeological and fossil record and are often used to interpret past environments and climate. This study focuses on the physical and chemical alteration that takes place during heating (i.e. charring). Modifications to the internal and external morphol

  3. Gas cleaning with hot char beds studied by stable isotopes

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ahrenfeldt, Jesper; Ambus, Per;

    2014-01-01

    with 2H (deuterium) were used to support proposed reaction mechanisms. It was found that at 700-800 °C the aromatic tar compounds bind irreversibly to the char by a radical reaction and, hence, become an integrated part of the char. Thermally induced reactions may occur prior to the binding reaction...

  4. Evaluation of solid fuel char briquettes from human waste.

    Science.gov (United States)

    Ward, Barbara J; Yacob, Tesfayohanes W; Montoya, Lupita D

    2014-08-19

    The developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C. Fecal chars made at 300 °C were found to be similar in energy content to wood chars and bituminous coal, having a heating value of 25.6 ± 0.08 MJ/kg, while fecal chars made at 750 °C had an energy content of 13.8 ± 0.48 MJ/kg. The higher heating values of the studied chars were evaluated using their elemental composition and a published predictive model; results found good agreement between the measured and predicted values. Fecal chars made at low temperatures were briquetted with molasses/lime and starch binders. Briquettes made with 10% starch had an average impact resistance index of 79 and a higher heating value of 25 MJ/kg. These values are comparable to those of commercial charcoal briquettes, making fecal char briquettes a potential substitute that also contributes to the preservation of the environment.

  5. Clean, premium-quality chars: Demineralized and carbon enriched

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.

    1992-01-03

    The goal of this project is to develop a bench-scale procedure to produce clean, desulfurized, premium-quality chars from the Illinois basin coals. This goal is achieved by utilizing the effective capabilty of smectites in combination with methane to manipulate the char yields. The major objectives are: to determine the optimum water- ground particle size for the maximum reduction of pyrite and minerals by the selective-bitumen agglomeration process; to evaluate the type of smectite and its interlamellar cation which enhances the premium-quality char yields; to find the mode of dispersion of smectites in clean coal which retards the agglomeration of char during mild gasification; to probe the conditions that maximize the desulfurized clean-char yields under a combination of methane+oxygen or helium+oxygen; to characterize and accomplish a material balance of chars, liquids, and gases produced during mild gasification; to identify the conditions which reject dehydrated smectites from char by the gravitational separation technique; and to determine the optimum seeding of chars with polymerized maltene for flammability and transportation.

  6. CHARCOAL PACKED FURNACE FOR LOW-TECH CHARRING OF BONE

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A low-tech furnace for charring of raw bone using char coal is developed and tested. The furnace consists of a standard oil drum, fitted with simple materials as available in every market in small towns in developing counties. 80 kg of raw bone and 6 kg of charcoal are used for production of 50 k...

  7. Compilation of Sandia coal char combustion data and kinetic analyses

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, R.E.; Hurt, R.H.; Baxter, L.L.; Hardesty, D.R.

    1992-06-01

    An experimental project was undertaken to characterize the physical and chemical processes that govern the combustion of pulverized coal chars. The experimental endeavor establishes a database on the reactivities of coal chars as a function of coal type, particle size, particle temperature, gas temperature, and gas and composition. The project also provides a better understanding of the mechanism of char oxidation, and yields quantitative information on the release rates of nitrogen- and sulfur-containing species during char combustion. An accurate predictive engineering model of the overall char combustion process under technologically relevant conditions in a primary product of this experimental effort. This document summarizes the experimental effort, the approach used to analyze the data, and individual compilations of data and kinetic analyses for each of the parent coals investigates.

  8. Endocrine disruption in brook trout (Salvelinus fontinalis) exposed to leachate from a public refuse dump

    NARCIS (Netherlands)

    Noaksson, E.; Linderoth, M.; Bosveld, A.T.C.; Norrgren, L.; Zebühr, Y.; Balk, L.

    2003-01-01

    Lake Molnbyggen was previously found to harbour a large number of sexually immature female perch (Perca fluviatilis) suffering from endocrine disruption. In an attempt to pin-point the source of the endocrine-disrupting substance(s) (EDSs), brook trout (Salvelinus fontinalis) from Vadbacken, a strea

  9. The effects of the conditions of char formation on the physical properties of charred phenolic-nylon

    Science.gov (United States)

    Smyly, E. D.; Pears, C. D.

    1972-01-01

    A study was made of the effects of the conditions of char formation on the physical properties of charred phenolic nylon of 0.577 gm/cu cm density. It was found that the thermal conductivity and several of the monitors correlate well with degradation conditions. The monitors included electrical resistivity, sonic velocity, porosity, lattice spacing and crystallite size.

  10. Chemical Constituents in Charred Sanguisorbae Radix

    Institute of Scientific and Technical Information of China (English)

    SUN Li-li; ZHONG Ying; XIA Hong-min; ZHOU Qian; LV Jia

    2013-01-01

    Objective To study the chemical constituents in the effective fractions of charred Sanguisorbae Radix.Methods The compounds were isolated and purified by column chromatography and their structures were identified on the basis of physicochemical properties and spectral analysis.Results Five compounds were isolated and identified as 3 β-hydroxy-28-norurs-17,19,21-trien (1),3 β-hydroxy-28-norurs-12,17-dien (2),3 β,19α-dihydroxyurs-13 (18)-en-28-oic acid (3),3β-[(α-L-arabin-opyranosyl) oxy]-28-norurs-12,17-dien (4),and pomolic acid (5).Conclusion Compounds 1,3,and 4 are novel compounds belong to triterpenoids and triterpenoid saponins,named as sanguisorbigenins Z,Y1,and Y2,respectively.

  11. A burnout prediction model based around char morphology

    Energy Technology Data Exchange (ETDEWEB)

    T. Wu; E. Lester; M. Cloke [University of Nottingham, Nottingham (United Kingdom). Nottingham Energy and Fuel Centre

    2005-07-01

    Poor burnout in a coal-fired power plant has marked penalties in the form of reduced energy efficiency and elevated waste material that can not be utilized. The prediction of coal combustion behaviour in a furnace is of great significance in providing valuable information not only for process optimization but also for coal buyers in the international market. Coal combustion models have been developed that can make predictions about burnout behaviour and burnout potential. Most of these kinetic models require standard parameters such as volatile content, particle size and assumed char porosity in order to make a burnout prediction. This paper presents a new model called the Char Burnout Model (ChB) that also uses detailed information about char morphology in its prediction. The model can use data input from one of two sources. Both sources are derived from image analysis techniques. The first from individual analysis and characterization of real char types using an automated program. The second from predicted char types based on data collected during the automated image analysis of coal particles. Modelling results were compared with a different carbon burnout kinetic model and burnout data from re-firing the chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen across several residence times. An improved agreement between ChB model and DTF experimental data proved that the inclusion of char morphology in combustion models can improve model predictions. 27 refs., 4 figs., 4 tabs.

  12. A burnout prediction model based around char morphology

    Energy Technology Data Exchange (ETDEWEB)

    Tao Wu; Edward Lester; Michael Cloke [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2006-05-15

    Several combustion models have been developed that can make predictions about coal burnout and burnout potential. Most of these kinetic models require standard parameters such as volatile content and particle size to make a burnout prediction. This article presents a new model called the char burnout (ChB) model, which also uses detailed information about char morphology in its prediction. The input data to the model is based on information derived from two different image analysis techniques. One technique generates characterization data from real char samples, and the other predicts char types based on characterization data from image analysis of coal particles. The pyrolyzed chars in this study were created in a drop tube furnace operating at 1300{sup o}C, 200 ms, and 1% oxygen. Modeling results were compared with a different carbon burnout kinetic model as well as the actual burnout data from refiring the same chars in a drop tube furnace operating at 1300{sup o}C, 5% oxygen, and residence times of 200, 400, and 600 ms. A good agreement between ChB model and experimental data indicates that the inclusion of char morphology in combustion models could well improve model predictions. 38 refs., 5 figs., 6 tabs.

  13. Gasification of biomass chars in steam-nitrogen mixture

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H. [Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey)]. E-mail: hanzade@itu.edu.tr; Yaman, S. [Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey); Kucukbayrak, S. [Department of Chemical Engineering, Chemical and Metallurgical Engineering Faculty, Istanbul Technical University, 34469 Maslak, Istanbul (Turkey)

    2006-05-15

    Some agricultural and waste biomass samples such as sunflower shell, pinecone, rapeseed, cotton refuse and olive refuse were first pyrolyzed in nitrogen, and then, their chars were gasified in a gas mixture of steam and nitrogen. Experiments were performed using the thermogravimetric analysis technique. Pyrolysis of the biomass samples was performed at a heating rate of 20 K/min from ambient to 1273 K in a dynamic nitrogen atmosphere of 40 cm{sup 3} min{sup -1}. The obtained chars were cooled to ambient temperature and then gasified up to 1273 K in a dynamic atmosphere of 40 cm{sup 3} min{sup -1} of a mixture of steam and nitrogen. Derivative thermogravimetric analysis profiles from gasification of the chars were derived, and the mass losses from the chars were interpreted in terms of temperature. It was concluded that gasification characteristics of biomass chars were fairly dependent on the biomass properties such as ash and fixed carbon contents and the constituents present in the ash. Different mechanisms in the three temperature intervals, namely water desorption at lower temperatures, decomposition of hydroxide minerals to oxide minerals and formation of carbon monoxide at medium temperatures and production of hydrogen at high temperatures govern the behavior of the char during the gasification process. The chars from pinecone and sunflower shell could be easily gasified under the mentioned conditions. In order to further raise the conversion yields, long hold times should be applied at high temperatures. However, the chars from rapeseed and olive refuse were not gasified satisfactorily. Low ash content and high fixed carbon content biomass materials are recommended for use in gasification processes when char from pyrolysis at elevated temperatures is used as a feedstock.

  14. Disintegration of beech wood char during thermal conversion

    DEFF Research Database (Denmark)

    Hindsgaul, Claus

    In the present work the processes occurring in the structures of slowly pyrolysed beech wood char during thermal gasification have been investigated. Emphasis was put on physical changes and gas transport properties during conversion. The highly anisotropic structure of wood was preserved in its...... differences of 3—4 orders of magnitude between the longitudinal and other directions in freshly pyrolysed beech wood char. Diffusion in the longitudinal direction of the beech wood char before gasification corresponded to direct, unobstructed diffusion through its vessel cells. Radial and tangential diffusion...

  15. Effect of char preparation temperature on the evolution of nitrogen-containing species during char oxidation at fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ren, W.; Lu, J.; Yue, G. [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Beer, J.M. [Massachusetts Inst. of Technology, Boston, MA (United States). Dept. of Chemical and Fuel Engineering; Molina, A.; Sarofim, A.F. [Utah Univ., Salt Lake City, UT (United States). Dept. of Chemical and Fuels Engineering

    2002-07-01

    Fluidized bed combustion is gaining popularity as a means to burn coal and waste fuels because the low temperatures of fluidized bed combustors generally result in low thermal nitric oxide (NO) production. However, nitrous oxide (N{sub 2}O) emissions can be relativity high and strategies must be developed to reduce emissions of this greenhouse gas. This paper presents the results of a laboratory study that examined the effect of pyrolysis temperature on the conversion of char-N to N{sub 2}O, NO and hydrogen cyanide (HCN) in fluidized bed combustion. When anthracite coal was used, an increase in the pyrolysis temperature resulted in reduced conversion of char-N to N{sub 2}O and HCN. However, the conversion to NO increased. This observation may be due to the lower hydrogen content of the chars produced at higher temperature and their lower reactivity. Other possibilities may be that the lower char reactivity for chars produced at high pyrolysis temperature may affect the reactions occurring in the boundary layer. Chars of lower reactivity in particular, may react at lower particle temperature and under high transient oxygen concentrations. A simplified char combustion representation was used to examine the effect of temperature and equivalence ratio on HCN oxidation. A reduction of equivalence ratio could explain some of the observed variations in product distribution with increased pyrolysis temperature. 19 refs., 1 tab., 5 figs.

  16. Visualizing the Stability of Char: Molecular- to Micron-scale Observations of Char Incubated in a Tropical Soil

    Science.gov (United States)

    Heckman, K. A.; Ramon, C.; Weber, P. K.; Torn, M. S.; Pett-Ridge, J.; Nico, P. S.

    2014-12-01

    The persistence of pyrogenic materials (hereafter referred to as char) in terrestrial ecosystems is of interest both from a carbon cycle modelling perspective and a climate change mitigation standpoint. However, the fate of newly introduced char in soils remains unclear. Recent reviews attempting to summarize trends in char decomposition have come to differing conclusions, further stressing the complexity of factors dictating char stability in soils. The current dataset specifically addresses the stability of char additions to a tropical clay-rich soil, possible priming effects, and interactions among char, microbial communities and the mineral matrix. 13C- and 15N-labeled Acer rubrum(red maple) wood was combusted at 400°C and added to surface (0-10 cm) and subsurface (20-30 cm) soils from the Luquillo Experimental Forest, Puerto Rico. Soils were incubated for 13 and 345 days at 26°C. Following incubation, intact microaggregates were frozen and cryosectioned into thin sections of approximately 5 μm thickness and mounted on gold-coated quartz slides. Thin sections were examined by synchrotron-based Fourier transform infrared spectroscopy (SR-FTIR), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), and high resolution secondary ion mass spectrometry (nanoSIMS). The combination of these μm to nm scale techniques allowed us to create corresponding spatial maps of native organic matter, char, and mineral phase distribution, track spatial variability in organic matter molecular structure, and dispersion of 13C and 15N isotopic labels. We present preliminary results indicating a high degree of stability of char in these wet tropical soils throughout the incubation period, suggesting that applied char may persist for long periods of time in similar soils.

  17. Thermal analysis of charring materials based on pyrolysis interface model

    Directory of Open Access Journals (Sweden)

    Huang Hai-Ming

    2014-01-01

    Full Text Available Charring thermal protection systems have been used to protect hypersonic vehicles from high heat loads. The pyrolysis of charring materials is a complicated physical and chemical phenomenon. Based on the pyrolysis interface model, a simulating approach for charring ablation has been designed in order to obtain one dimensional transient thermal behavior of homogeneous charring materials in reentry capsules. As the numerical results indicate, the pyrolysis rate and the surface temperature under a given heat flux rise abruptly in the beginning, then reach a plateau, but the temperature at the bottom rises very slowly to prevent the structural materials from being heated seriously. Pyrolysis mechanism can play an important role in thermal protection systems subjected to serious aerodynamic heat.

  18. Experimental Study of Hydrogasification of Lignite and Subbituminous Coal Chars

    Directory of Open Access Journals (Sweden)

    Stanisław Gil

    2015-01-01

    Full Text Available The experimental facility for pressure hydrogasification research was adapted to the pressure of 10 MPa and temperature of 1300 K, which ensured repeatability of results and hydrogen heating to the process temperature. A hydrogasification reaction of chars produced from two rank coals was investigated at temperatures up to 1173 K, pressures up to 8 MPa, and the gas flow rates of 0.5–5 dmn3/min. Reactivity of the “Szczerców” lignite char was found to be slightly higher than that of the subbituminous “Janina” coal char produced under the same conditions. A high value of the char reactivity was observed to a certain carbon conversion degree, above which a sharp drop took place. It was shown that, to achieve proper carbon conversion, the hydrogasification reaction must proceed at a temperature above 1200 K.

  19. Direct reduction of iron ore by biomass char

    Science.gov (United States)

    Zuo, Hai-bin; Hu, Zheng-wen; Zhang, Jian-liang; Li, Jing; Liu, Zheng-jian

    2013-06-01

    By using thermogravimetric analysis the process and mechanism of iron ore reduced by biomass char were investigated and compared with those reduced by coal and coke. It is found that biomass char has a higher reactivity. The increase of carbon-to-oxygen mole ratio (C/O) can lead to the enhancement of reaction rate and reduction fraction, but cannot change the temperature and trend of each reaction. The reaction temperature of hematite reduced by biomass char is at least 100 K lower than that reduced by coal and coke, the maximum reaction rate is 1.57 times as high as that of coal, and the final reaction fraction is much higher. Model calculation indicates that the use of burden composed of biomass char and iron ore for blast furnaces can probably decrease the temperature of the thermal reserve zone and reduce the CO equilibrium concentration.

  20. Effects of roads on bull trout (Salvelinus confluentus), a federally threatened species

    OpenAIRE

    Teachout, Emily; Quan, Jennifer

    2001-01-01

    The bull trout (Salvelinus confluentus) is federally listed as threatened under the Endangered Species Act. Bull trout are apex predators requiring a large prey base and a large home range, and are known to move throughout and between basins in search of prey. However, bull trout are dependent upon very cold, clean waters for spawning (below 9 degrees Celsius) and are typically characterized as spawning in the upper-most reaches of watersheds. Bull trout have four life history forms: resident...

  1. Preparation and characterization of activated carbon from demineralized tyre char

    Science.gov (United States)

    Manocha, S.; Prasad, Guddu R.; Joshi, Parth.; Zala, Ranjitsingh S.; Gokhale, Siddharth S.; Manocha, L. M.

    2013-06-01

    Activated carbon is the most adsorbing material for industrial waste water treatment. For wider applications, the main consideration is to manufacture activated carbon from low cost precursors, which are easily available and cost effective. One such source is scrap tyres. Recently much effort has been devoted to the thermal degradation of tyres into gaseous and liquid hydrocarbons and solid char residue, all of which have the potential to be processed into valuable products. As for solid residue, char can be used either as low-grade reinforcing filler or as activated carbon. The product recovered by a typical pyrolysis of tyres are usually, 33-38 wt% pyrolytic char, 38-55 wt% oil and 10-30 wt% solid fractions. In the present work activated carbon was prepared from pyrolyzed tyre char (PC). Demineralization involves the dissolution of metal into acids i.e. HCl, HNO3 and H2SO4 and in base i.e. NaOH. Different concentration of acid and base were used. Sodium hydroxide showed maximum amount of metal oxide removal. Further the concentration of sodium hydroxide was varied from 1N to 6N. As the concentration of acid are increased demineralization increases. 6N Sodium hydroxide is found to be more effective demineralising agent of tyre char.

  2. Gasification reactivity of biomass chars with CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong Kyun; Lee, Sun Ki; Kang, Min Woong; Hwang, Jungho [Department of Mechanical Engineering, Yonsei University, 134 Sinchon-dong, Seodaemun-gu, Seoul (Korea, Republic of); Yu, Tae-U. [High Temperature Processing R and D Department of Korea Institute of Industrial Technology, 35-3, Hongchon-Ri, Ipchang-Myun, Seobuk-Gu, Chonan-Si (Korea, Republic of)

    2010-12-15

    In this study, carbon conversion was calculated from the data obtained with a real-time gas analyzer. In a lab-scale furnace, each biomass sample was pyrolyzed in a nitrogen environment and became biomass char. For preparation of the char, the furnace was electrically heated over 40 min up to the wall temperature of 850 C, and maintained at the same temperature over 17 min. The furnace was again heated over 3 min to a temperature higher than 850 C and then CO{sub 2} was injected. The biomass char was then gasified with CO{sub 2} under isothermal conditions. The reactivity of biomass char was investigated at various temperatures and CO{sub 2} concentrations. The VRM (volume reaction model), SCM (shrinking core model), and RPM (random pore model) were used to interpret the experimental data. For each model, the activation energy (E) and pre-exponential factor (A) of the biomass char-CO{sub 2} reaction were determined from gas-analysis data by using the Arrhenius equation. For the RPM, the apparent reaction order was determined. According to this study, it was found that the experimental data agreed better with the RPM than with the other two models. Through BET analyses, it was found that the structural parameter ({psi}) of the surface area for the RPM was obtained as 4.22. (author)

  3. Bio-char from treated and untreated oil palm fronds

    Science.gov (United States)

    Sulaiman, Fauziah; Abdullah, Nurhayati; Rahman, Aizuddin Abdul

    2013-05-01

    The palm oil industry generates almost 94% of biomass in Malaysia, while other agricultural and forestry by-products contribute the remaining of 6%. Oil palm fronds (OPF) are estimated to be the highest available biomass amounting to 44.84 million tonnes in Malaysia. However, studies on OPF for thermochemical conversion technology which has good potential for energy conversion are still lacking. In this work, pyrolysis of OPF is conducted by using a fixed bed reactor. Samples were carbonized at slow pyrolysis temperature of around 300 to 500°C with heating rate of 10°C min-1. In addition, samples were treated for 20 min with distilled water at ambient temperature to reduce the ash content. Effectiveness of pre-treatment can be determined by observing the percentage of ash content reduction of each sample after undergoing washing pre-treatment. At 300°C, the char yields of the untreated OPF were slightly higher at 50.95% compared to the treated sample at 49.77%. Approximately all bio-char from the treated samples have better high heating value (HHV) of around 18-20 MJ kg-1 compared to the untreated samples. Besides that, all treated OPF char is more carbon rich and considered to be environmental friendly due to its low nitrogen content compared to the untreated OPF char. In this work, microscopic analysis of OPF bio-char were also studied by observing and evaluating their structure surface and morphology.

  4. Study on pore structure properties of steam activated biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    Shu, Tong; Lu, Fei; Wang, Qinchao; Lu, Ping [Nanjing Normal Univ. (China). School of Energy and Mechanical Engineering

    2013-07-01

    Wheat straw and rice husk chars were prepared in a fixed bed reactor at different pyrolysis temperatures (673, 873 and 1,073K) and different pyrolysis procedure. The steam activated chars were also prepared in a fixed bed reactor at the following conditions: activation temperature is 1,073K, the flow rate of N{sub 2} is 5L/min, and N{sub 2} and H{sub 2}O molar ratio is 1:1. The specific surface area, pore structure and micro-morphology of different kinds of prepared biomass chars were measured by NOVA1000e analysis instrument and JSM-5610LV scanning electron microscopy (SEM), respectively. Results indicated that the internal structure was improved significantly by steam activation through enlarging the specific surface area and enriching the porosity. The wheat straw char prepared by both rapid pyrolysis at 873K and activation by steam is better than others, whose DR surface area increases from 3.10 to 1099.99m{sup 2}/g. The N{sub 2} adsorption volume of steam activated biomass chars has been significant promoted.

  5. Estimating thermodynamic properties of coal, char, tar and ash

    Energy Technology Data Exchange (ETDEWEB)

    Eisermann, W.; Johnson, P. Conger, W.L.

    1980-01-01

    Methods of predicting the specific heat, enthalpy, and entropy of coal, char, tar and ash as a function of temperature and material composition are presented. The standard entropy of coal is approximated by comparing the behaviour of the standard entropies of a number of aliphatic and aromatic hydrocarbons as a function of the variables H/(C + N), O/(C + N), N/(C + N), and S/(C + N), where the variables are the atomic fractions of the respective elements. The standard entropy of a bituminous coal was found to be about 20 kJ/kmol carbon K and of the char to be about 10 kJ/kmol carbon K. Estimates of the enthalpy difference between 273 K and temperatures above 273 K deviated from published data by about 8.49% for chars and 8.55% for coals on the average. Maximum deviations of 18.3% and 17.6% respectively were found.

  6. Mechanical Characterization of Bio-Char Made Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Amit pandey

    2016-08-01

    Full Text Available Material discoveries and development have always been the cause of the growth and development of a nation and the need of naturally made materials is the need of hours. Thus this paper takes you to the development of a hybrid composite made of sisal fiber with epoxy as the matrix intertwined with softwood bio-char. Softwood chip bio-char, produced by slow pyrolysis, has a porous structure improving its nutrient absorbing capacity, surface area and thus a potential substituent. Bio-char has an appreciable carbon sequestration value i.e. a carbon absorbing product. The orientation of sisal fiber are changed and studied in longitudinal and orthogonal direction indicating superiority of longitudinal fiber orientation .It also addresses the variation in mechanical characteristic (tensile flexural and impact with different constituent of the new composite and its position in material selection charts with a direction for further work.

  7. Studying the specific features pertinent to combustion of chars obtained from coals having different degrees of metamorphism and biomass chars

    Science.gov (United States)

    Bestsennyi, I. V.; Shchudlo, T. S.; Dunaevskaya, N. I.; Topal, A. I.

    2013-12-01

    Better conditions for igniting low-reaction coal (anthracite) can be obtained, higher fuel burnout ratio can be achieved, and the problem of shortage of a certain grade of coal can be solved by firing coal mixtures and by combusting coal jointly with solid biomass in coal-fired boilers. Results from studying the synergetic effect that had been revealed previously during the combustion of coal mixtures in flames are presented. A similar effect was also obtained during joint combustion of coal and wood in a flame. The kinetics pertinent to combustion of char mixtures obtained from coals characterized by different degrees of metamorphism and the kinetics pertinent to combustion of wood chars were studied on the RSK-1D laboratory setup. It was found from the experiments that the combustion rate of char mixtures obtained from coals having close degrees of metamorphism is equal to the value determined as a weighted mean rate with respect to the content of carbon. The combustion rate of char mixtures obtained from coals having essentially different degrees of metamorphism is close to the combustion rate of more reactive coal initially in the process and to the combustion rate of less reactive coal at the end of the process. A dependence of the specific burnout rate of carbon contained in the char of two wood fractions on reciprocal temperature in the range 663—833 K is obtained. The combustion mode of an experimental sample is determined together with the reaction rate constant and activation energy.

  8. Heat Transfer in a Fixed Bed of Straw Char

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Jensen, Anker

    2003-01-01

    A model for the thermal conductivity of a straw char bed has been developed. The model extends the work of Yagi and Kunii to describe heat transfer in a bed of cylinders, using a relationship between the interparticle distance and the external porosity. To verify the model, thermal conductivity...... the experimental uncertainty over the range of conditions investigated. The heat transfer model was used in a parametric study to evaluate the effect of gas flow rate, particle diameter, porosity, and temperature on the thermal conductivity in a straw char bed....

  9. Heat Transfer in a Fixed Biomass Char Bed

    DEFF Research Database (Denmark)

    Fjellerup, Jan Søren; Henriksen, Ulrik Birk; Glarborg, P.

    2002-01-01

    A thermal conductivity model based on the Yagi and Kunii model together with a bed model was developed to describe the thermal conductivity of a straw char bed. The bed model describes the relationship between the distance between particles and the external porosity. To verify the model, thermal...... conductivity experiments were performed on a wheat straw sample, which were cut in a shredder with two different sieves, 4 and 8 mm, and packed loosely in the thermal conductivity apparatus. The model, using external porosity and char diameter, compared reasonable well with experiments. The two straw samples...

  10. 花糕红点鲑多态性微卫星筛选及鸭绿江种群遗传多样性分析%Screening of Polymorphisic Microsatellite and Genetic Diversity in Yalu River Population of Dolly Varden Salvelinus malma

    Institute of Scientific and Technical Information of China (English)

    马波

    2012-01-01

    The polymorphic primers for Dolly Varden Salvelinus malma as a rare and endangered cold-water species in China was screened from char S.confluentus by microsatellite,and the genetic diversity of the Yalu River population was analyzed.The results showed that 5 microsatellite primers screened from 10 microsatellite primers in Salvelinus malma were polymorphous in Dolly Varden.There were the number of alleles(Na) of 6~22(average 15),heteroerozygosity(H) of 0.4063~0.9333(average 0.7851) and polymorphic information content(PIC) of 0.716 4~0.919 8(average 0.8536) in Yalu River population of Dolly Varden.The findings indicated that the 5 primers from S.confluentus provided a good versatility in dolly varden,and a high level of genetic diversity in Yalu River population,which provides a genetics theoretical basis for the protection and management of germoplasm resources of Dolly Varden in China.%利用强壮红点鲑(Salvelinus confluentus)的微卫星筛选出适用于我国的珍稀濒危冷水性鱼类——花糕红点鲑(Salvelinus malma)的多态性引物,并分析其鸭绿江种群的遗传多样性。结果显示,在强壮红点鲑的10个微卫星引物中有5个在花糕红点鲑群体中具有多态性,鸭绿江种群的等位基因数(N)a为6~22(平均15),杂合度(H)为0.4063~0.9333(平均0.7851),多态信息含量(PIC)为0.7164~0.9198(平均0.8536)。强壮红点鲑微卫星引物在花糕红点鲑中具有很好的通用性,花糕红点鲑的鸭绿江种群具有较高的遗传多样性水平。本研究结果为我国花糕红点鲑种质资源保护和管理提供遗传学理论依据。

  11. Formation, Structure and Properties of Amorphous Carbon Char from Polymer Materials in Extreme Atmospheric Reentry Environments

    Science.gov (United States)

    Lawson, John W.

    2010-01-01

    Amorphous carbonaceous char produced from the pyrolysis of polymer solids has many desirable properties for ablative heat shields for space vehicles. Molecular dynamics simulations are presented to study the transformation of the local atomic structure from virgin polymer to a dense, disordered char [1]. Release of polymer hydrogen is found to be critical to allow the system to collapse into a highly coordinated char structure. Mechanisms of the char formation process and the morphology of the resulting structures are elucidated. Thermal conductivity and mechanical response of the resulting char are evaluated [2]. During reenty, the optical response and oxidative reactivity of char are also important properties. Results of ab initio computations of char optical functions [3] and char reactivity [4] are also presented.

  12. Experimental comparison of biomass chars with other catalysts for tar reduction

    NARCIS (Netherlands)

    Abu El-Rub, Z.; Bramer, E.A.; Brem, G.

    2008-01-01

    In this paper the potential of using biomass char as a catalyst for tar reduction is discussed. Biomass char is compared with other known catalysts used for tar conversion. Model tar compounds, phenol and naphthalene, were used to test char and other catalysts. Tests were carried out in a fixed bed

  13. Low-energy and chemical-free activation of pyrolytic tire char and its adsorption characteristics.

    Science.gov (United States)

    Quek, Augustine; Balasubramanian, Rajasekhar

    2009-06-01

    It is generally known that the solid char obtained from pyrolysis of scrap rubber tires can be used as an adsorbent for several applications such as wastewater treatment. In this study, scrap tires were first pyrolyzed under nitrogen (N2) or carbon dioxide (CO2) gas under various temperatures to produce char. The char was activated in situ by post-pyrolysis oxygenation (PPO) at different temperature ranges as soon as the pyrolysis process was completed. Elemental and spectroscopic analyses showed significant zinc content in the char after PPO. Batch-mode removal of aqueous copper (Cu) using the chars revealed that, for N2 and CO2, the optimum condition for pyrolysis was at 550 degrees C and for activation was from 550 to 250 degrees C. Although CO2-pyrolyzed char had lower Cu and lead (Pb) removal than N2-pyrolyzed char, it had higher char yields. For both N2- and CO2-pyrolyzed char, activation with PPO improved their heavy metal removal efficiencies significantly compared with unactivated char. PPO chars had much faster removal rates and higher Cu removal compared with both pyrolyzed, unactivated char and commercial activated carbons.

  14. Particle-based characterisation of pulverised coals and chars for carbon burnout studies

    Energy Technology Data Exchange (ETDEWEB)

    Gibbins, J.R.; Seitz, M.H.; Kennedy, S.M.; Beeley, T.J.; Riley, G.S. [Imperial College of Science, Technology and Medicine, London (United Kingdom). Mechanical Engineering Department

    1999-07-01

    The study of individual particle properties, as opposed to averaged behaviour of differing particles, was carried out for the combustion of coals and chars using optical microscopy and digital image processing. Chars from entrained flow reactors and corresponding pulverized fuel samples were characterized to examine possible char particle origins for real heterogeneous particles. 7 refs., 5 figs., 1 tab.

  15. Bone char quality and defluoridation capacity in contact precipitation

    DEFF Research Database (Denmark)

    Albertus, J.; Bregnhøj, Henrik; Kongpun, M.

    2002-01-01

    Samples from six different brands of bone char are tested for their capacity to remove fluoride from water in batch. Initial concentrations of 10 mg/L and contact times of 6 hours are used. The removal capacities observed are 0.6-1.1 mg/g on an average, s.d. being 0.16. Addition of calcium and ph...

  16. Do stocked hatchery-reared juveniles ecologically suppress wild juveniles in Salvelinus leucomaenis?

    Science.gov (United States)

    Nakamura, T; Doi, T

    2014-05-01

    The dominancy of semi-wild and hatchery-reared white-spotted charr Salvelinus leucomaenis juveniles was evaluated using pair-wise enclosure tests and field stocking tests. The semi-wild S. leucomaenis originated in a hatchery, being stocked into the test stream as eyed-eggs. In the pair-wise enclosure test, the semi-wild S. leucomaenis dominated the hatchery S. leucomaenis that were of a similar standard length (L(S) ). The semi-wild S. leucomaenis were subordinate to hatchery S. leucomaenis that were > 11% larger in LS . In the field stocking test, the abundance and growth of semi-wild S. leucomaenis was decreased in the presence of larger hatchery S. leucomaenis (14% larger LS ). Taken together, these results suggest that larger hatchery S. leucomaenis ecologically suppress the smaller semi-wild S. leucomaenis. Salvelinus leucomaenis juveniles that are stocked with the intention of supplementing natural populations should be < 10% larger than their wild counterparts at the time of stocking to minimize their competitive advantage. The semi-wild and hatchery S. leucomaenis used in both tests were genetically similar individuals, suggesting that the differences are due to the early rearing environment of either a natural stream or hatchery. The hatchery S. leucomaenis have lower levels of aggression as a result of selection in the hatchery rearing environment. Rearing in a natural stream from the eyed-egg stage is likely to increase their lowered aggression.

  17. Structure Based Predictive Model for Coal Char Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Robert Hurt; Joseph Calo; Robert Essenhigh; Christopher Hadad

    2000-12-30

    This unique collaborative project has taken a very fundamental look at the origin of structure, and combustion reactivity of coal chars. It was a combined experimental and theoretical effort involving three universities and collaborators from universities outside the U.S. and from U.S. National Laboratories and contract research companies. The project goal was to improve our understanding of char structure and behavior by examining the fundamental chemistry of its polyaromatic building blocks. The project team investigated the elementary oxidative attack on polyaromatic systems, and coupled with a study of the assembly processes that convert these polyaromatic clusters to mature carbon materials (or chars). We believe that the work done in this project has defined a powerful new science-based approach to the understanding of char behavior. The work on aromatic oxidation pathways made extensive use of computational chemistry, and was led by Professor Christopher Hadad in the Department of Chemistry at Ohio State University. Laboratory experiments on char structure, properties, and combustion reactivity were carried out at both OSU and Brown, led by Principle Investigators Joseph Calo, Robert Essenhigh, and Robert Hurt. Modeling activities were divided into two parts: first unique models of crystal structure development were formulated by the team at Brown (PI'S Hurt and Calo) with input from Boston University and significant collaboration with Dr. Alan Kerstein at Sandia and with Dr. Zhong-Ying chen at SAIC. Secondly, new combustion models were developed and tested, led by Professor Essenhigh at OSU, Dieter Foertsch (a collaborator at the University of Stuttgart), and Professor Hurt at Brown. One product of this work is the CBK8 model of carbon burnout, which has already found practical use in CFD codes and in other numerical models of pulverized fuel combustion processes, such as EPRI's NOxLOI Predictor. The remainder of the report consists of detailed

  18. The densification of bio-char: Effect of pyrolysis temperature on the qualities of pellets.

    Science.gov (United States)

    Hu, Qiang; Yang, Haiping; Yao, Dingding; Zhu, Danchen; Wang, Xianhua; Shao, Jingai; Chen, Hanping

    2016-01-01

    The densification of bio-chars pyrolyzed at different temperatures were investigated to elucidate the effect of temperature on the properties of bio-char pellets and determine the bonding mechanism of pellets. Optimized process conditions were obtained with 128MPa compressive pressure and 35% water addition content. Results showed that both the volume density and compressive strength of bio-char pellets initially decreased and subsequently increased, while the energy consumption increased first and then decreased, with the increase of pyrolysis temperature. The moisture adsorption of bio-char pellets was noticeably lower than raw woody shavings but had elevated than the corresponding char particles. Hydrophilic functional groups, particle size and binder were the main factors that contributed to the cementation of bio-char particles at different temperatures. The result indicated that pyrolysis of woody shavings at 550-650°C and followed by densification was suitable to form bio-char pellets for application as renewable biofuels.

  19. Effect of temperature and pressure on characteristics and reactivity of biomass-derived chars.

    Science.gov (United States)

    Recari, J; Berrueco, C; Abelló, S; Montané, D; Farriol, X

    2014-10-01

    This study evaluates the influence of pyrolysis temperature (350-450°C) and pressure (0.1-2.0MPa) on product yields and char properties. Spruce chars were produced under slow pyrolysis conditions in a fixed bed reactor. Special attention was devoted to the study of the oxidation reactivity of the produced chars, and its relationship with the evaluated char properties. The obtained results showed that the effect of the pyrolysis condition on char production and in particular on the mechanism of secondary char formation strongly influenced the char reactivity. Additionally it has been observed that the interval of temperature between 350 and 450°C may be key in the mechanism of tar repolymerization. The information provided in this study is of great interest for the determination of optimal operation conditions and the design of new gasification concepts or the development of bioenergy carriers via pyrolysis technologies.

  20. A study on the char burnout characteristics of coal and biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Behdad Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, School of Engineering, Faculty of Engineering and Built Environment

    2007-10-15

    The char burnout characteristics of coal/biomass blends under conditions pertinent to pulverised fuel combustors were investigated by a combined modelling and experimental approach. Results indicate that blending of coal with biomass increases the likelihood of char extinction (i.e. extinction potential of the char particle in the blend), in turn, decreasing the char burnout level. Our modelling results attribute this to a reduction in the char particle size to levels below a critical dimension which appears to be a strong function of the fuel blending ratio (the weight percentage of biomass in the blend), fuel reactivity, char cloud shape and particle density number. It is demonstrated here that the drop in the char burnout level during co-firing can be effectively resolved when a more reactive secondary coal is added to the blend to minimise its extinction potential. 22 refs., 8 figs., 2 tabs.

  1. Combustion Characteristics of Lignite Char in a Laboratory-scale Pressurized Fluidized Bed Combustor

    Science.gov (United States)

    Murakami, Takahiro; Suzuki, Yoshizo

    In a dual fluidized bed gasifier, the residual char after steam gasification is burnt in riser. The objectives of this work are to clarify the effect of parameters (temperature, pressure, and particle size of lignite char) of char combustion using a laboratory-scale pressurized fluidized bed combustor (PFBC). As a result, the burnout time of lignite char can be improved with increasing operating pressure, and temperature. In addition, the decrease in the particle size of char enhanced the effect on burnout time. The initial combustion rate of the char can be increased with increasing operating pressure. The effect was decreased with increasing operating temperature. However, the effect of operating pressure was slightly changed in small particle size, such as 0.5-1.0 mm. It takes about 20 sec to burn 50% of char in the operating pressure of 0.5 MPa and the particle size of 0.5-1.0 mm.

  2. Life Cycle Assessment of Biochar - EuroChar Project

    Science.gov (United States)

    Rack, M.; Woods, J.

    2012-04-01

    One of the most significant challenges faced by modern-day society is that of global warming. An exclusive focus on reducing the greenhouse gas (GHG) emissions will not suffice and therefore technologies capable of removing CO2 directly from the atmosphere at low or minimal cost are gaining increased attention. The production and use of biochar is an example of such an emerging mitigation strategy. However, as with any novel product, process and technology it is vital to conduct an assessment of the entire life cycle in order to determine the environmental impacts of the new concept in addition to analysing the other sustainability criteria. Life Cycle Assessment (LCA), standardized by ISO (2006a), is an example of a tool used to calculate the environmental impacts of a product or process. Imperial College London will follow the guidelines and recommendations of the ISO 14040 series (ISO 2002, ISO 2006a-b) and the International Life Cycle Data System (ILCD) Handbook (EC JRC IES, 2010a-e), and will use the SimaPro software to conduct a LCA of the biochar supply chains for the EuroChar project. EuroChar ('biochar for Carbon sequestration and large-scale removal of GHG from the atmosphere') is a project funded by the European Commission under its Seventh Framework Programme (FP7). EuroChar aims to investigate and reduce uncertainties around the impacts of, and opportunities for, biochar and, in particular, explore a possible introduction into modern agricultural systems in Europe, thereby moving closer to the determination of the true potential of biochar. EuroChar will use various feedstocks, ranging from wheat straw to olive residues and poplar, as feedstocks for biochar production and will focus on two conversion technologies, Hydrothermal Carbonization (HTC) and Thermochemical Carbonization (TC), followed by the application of the biochar in crop-growth field trials in England, France and Italy. In April 2012, the EuroChar project will be at its halfway mark and

  3. Effect of the heating rate on the morphology of the pyrolytic char from hazelnut shell

    Energy Technology Data Exchange (ETDEWEB)

    Hanzade, H.A.; Serdar, Y. [Istanbul Technical Univ., Istanbul (Turkey). Faculty of Chemical and Metallurgical Engineering

    2008-07-01

    Although biomass chars have a high potential for use in various applications, their performance is directly related to the chemical and the physical properties of the chars. The surface area, porosity, pore size distribution, and density are the physical properties that determine the suitability of the chars to be used. Hazelnut shells are touted as being an extremely appropriate feedstock for high quality pyrolytic char, but the working conditions under which char is obtained have significant influence on the char structure and its properties, such as the thermal reactivity. Therefore, effects of the various parameters on the char structure must be considered. In this context, the present study focused on the physical changes that occur in char as a result of different heating rates during the pyrolysis of hazelnut shells. The effects of the heating rate on the structure of the pyrolytic char obtained from ground hazelnut shells under six different heating rate conditions were investigated. The hazelnut shell was burned in a thermogravimetric analyzer (TGA) under nitrogen flow. Non-isothermal heating was performed from ambient to 900 degrees C and held at this temperature until no further mass loss occurred. The changes in char morphology were studied with respect to the heating rate during charring. Scanning electron microscopy (SEM) was used with each char sample to determine the effect of heating rate. The dominant inorganic phases found in hazelnut shells were found to survive in the char. It was concluded that the high lignin content found in the char played a critical role in the decomposition mechanism. 3 refs., 2 tabs., 2 figs.

  4. Morphological changes during oxidation of a single char particle

    Energy Technology Data Exchange (ETDEWEB)

    d' Amore, M. (Salerno Univ. (Italy). Dept. of Chemical and Food Engineering); Tognotti, L. (Pisa Univ. (Italy). Dept. of Chemical Engineering); Sarofim, A.F. (Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering)

    1992-01-01

    In this study, the changes with conversion in morphology of a carbon char in the temperature range 500--1200 K are followed by using an electrodynamic balance (EDB) (Spjut et al., 1985; Dudek, 1988; Bar-ziv et al., 1989). This device allows one to measure in situ, over temperature range wider than in other apparatuses, mass, diameter, density, surface area, rate of reaction and temperature for a single, suspended submillimeter particle. By following with the EDB the changes in the char as it reacts, it is possible to study the influence of the porous texture on the reaction behavior and shed some light on the contribution by micropores to the reaction in the chemical kinetic controlled regime.

  5. Thermogravimetric characteristics of char obtained at high heat rate

    Directory of Open Access Journals (Sweden)

    Andrés Felipe Rojas González

    2010-05-01

    700°C, 800°C and 900°C to obtain their combustion profiles. Characteristic temperatures (ignition, peak and final tempe- ratures were determined by non-isothermal thermogravimetry; it was found that chars from La Yolanda coal gave the highest figures for the characteristic temperatures. Isothermal thermogravimetry revealed that the combustion rate for the three coals decreased with increased devolatilisation time and combustion temperature.

  6. Efficacy of Locust Beans Husk Char in Heavy Metal Sequestration

    OpenAIRE

    Ademola Ayodeji Ajayi-Banji; Temitayo Ewemoje; Adeniyi Ajimo

    2016-01-01

    Most solid waste management schemes minimally consider low concentration biodegradable agricultural waste management, though the environmental impact of this waste category is significant over a time frame. The column-mode study seeks to address the issue by suggesting potential utilisation of post-harvest waste for heavy metal sequestering. Locust beans husk char of 100 and 200 g was employed to inspect removal efficiency, isotherm and kinetic models of some heavy metals at 30, 60, 90, 120 a...

  7. Phosphorus Availability in Soils Amended with Wheat Residue Char

    OpenAIRE

    Parvage, Md. Masud; Ulén, Barbro; Eriksson, Jan; Strock, Jeffery; Kirchmann, Holger

    2013-01-01

    Plant availability and risk for leaching and/or runoff losses of phosphorus (P) from soils depends among others on P concentration in the soil solution. Water soluble P in soil measures soil solution P concentration. The aim of this study was to understand the effect of wheat residue char (biochar) addition on water soluble P concentration in a wide range of biochar amended soils. Eleven agricultural fields representing dominant soil texture classes of Swedish agricultural lands were chosen. ...

  8. Investigation of growth responses in saprophytic fungi to charred biomass

    OpenAIRE

    Ascough, P.L.; Sturrock, C. J.; Bird, M. I.

    2010-01-01

    We present the results of a study testing the response of two saprophytic white-rot fungi species, Pleurotus pulmonarius and Coriolus versicolor, to charred biomass (charcoal) as a growth substrate. We used a combination of optical microscopy, scanning electron microscopy, elemental abundance measurements, and isotope ratio mass spectrometry (13C and 15N) to investigate fungal colonisation of control and incubated samples of Scots Pine (Pinus sylvestris) wood, and charcoal from the same speci...

  9. Formation of hydrothermal biochar and char stability in soils

    Science.gov (United States)

    Baumert, Julia; Gleixner, Gerd

    2010-05-01

    The use of charcoal as an artificial soil additive is suggested to beneficially modify degraded soil, reduce greenhouse gas emission and improve crop yields. So far research has been mainly done using pyrolysis chars which are produced by dry pyrolysis of biomass. Here we used hydrothermal carbonisation (HTC). In this process wet biomass is converted to char at moderate temperatures (~200°C). Due to the exothermal carbonisation reaction this process is almost energy neutral, i.e. the energy needed to start the carbonisation equals the energy released during carbonisation. Different process parameters have been used to modify the properties of the produced chars. We examined the chemical and morphological properties of hydrothermally synthesized biochar. Cellulose, yeast and sucrose were used as model substances for a range of parent material types like organic and garden waste as well as residues from biogas production. By modifying the process conditions of hydrothermal carbonisation concerning temperature (180°C to 220°C) and duration (6 hours to 24 hours) we produced a variety of different biochars. Our findings suggest that the elemental composition and the thermal stability of resulting chars depend on the feedstock and production conditions. Functional group chemistry determined by NMR shows that the aromaticity of the product increases as a function of temperature whereas the amount of O-alkylic compounds declines, concurrently. Our results show that the properties of the biochar can be manipulated by the modification of process conditions. This opens the opportunity to adjust the charcoal to a given soil type.

  10. BONE CHAR BASED BUCKET DEFLUORIDATOR IN TANZANIAN HOUSEHOLDS

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    A household defluoridator, made of a 20 L plastic bucket and 10 kg of bone char, is tested and found efficient to remove fluoride at a capacity of 1.1 mg/g. On an average, the defluoridator reduced the original contents of 8.5 mgF/L to 0.37 mgF/L, i.e. 95.6 %, for a period of 2 months, where 32.5...

  11. Estimating thermodynamic properties of coal, char, tar and ash

    Energy Technology Data Exchange (ETDEWEB)

    Eisermann, W.; Johnson, P.; Conger, W.L.

    1980-01-01

    Methods for predicting the specific heat, enthalpy, and entropy of coal, char, tar and ash as a function of temperature and material composition are presented. The standard entropy of coal is approximated by comparing the behavior of the standard entropies of a number of aliphatic and aromatic hydrocarbons as a function of the variables H/(C + N), O/(C + N), N/(C + N), and S/(C + N), where the variables are the atomic fractions of the respective elements. The standard entropy of a bituminous coal was found to be about 20 kJ/kmol carbon K and of the char to be about 10 kJ/kmol carbon K. Estimates of the enthalpy difference between 273 K and temperatures above 273 K deviated from published data by about 8.49% for chars and 8.55% for coals on the average. Maximum deviations of 18.3% and 17.6% respectively were found. 10 figures, 4 tables.

  12. Structure-Based Predictive model for Coal Char Combustion.

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.; Colo, J [Brown Univ., Providence, RI (United States). Div. of Engineering; Essenhigh, R.; Hadad, C [Ohio State Univ., Columbus, OH (United States). Dept. of Chemistry; Stanley, E. [Boston Univ., MA (United States). Dept. of Physics

    1997-09-24

    During the third quarter of this project, progress was made on both major technical tasks. Progress was made in the chemistry department at OSU on the calculation of thermodynamic properties for a number of model organic compounds. Modelling work was carried out at Brown to adapt a thermodynamic model of carbonaceous mesophase formation, originally applied to pitch carbonization, to the prediction of coke texture in coal combustion. This latter work makes use of the FG-DVC model of coal pyrolysis developed by Advanced Fuel Research to specify the pool of aromatic clusters that participate in the order/disorder transition. This modelling approach shows promise for the mechanistic prediction of the rank dependence of char structure and will therefore be pursued further. Crystalline ordering phenomena were also observed in a model char prepared from phenol-formaldehyde carbonized at 900{degrees}C and 1300{degrees}C using high-resolution TEM fringe imaging. Dramatic changes occur in the structure between 900 and 1300{degrees}C, making this char a suitable candidate for upcoming in situ work on the hot stage TEM. Work also proceeded on molecular dynamics simulations at Boston University and on equipment modification and testing for the combustion experiments with widely varying flame types at Ohio State.

  13. Concomitant Antibiotic and Mercury Resistance Among Gastrointestinal Microflora of Feral Brook Trout, Salvelinus fontinalis

    Science.gov (United States)

    Meredith, Matthew M.; Parry, Erin M.; Guay, Justin A.; Markham, Nicholas O.; Danner, G. Russell; Johnson, Keith A.; Barkay, Tamar; Fekete, Frank A.

    2013-01-01

    Twenty-nine bacterial isolates representing eight genera from the gastrointestinal tracts of feral brook trout Salvelinus fontinalis (Mitchell) demonstrated multiple maximal antibiotic resistances and concomitant broad-spectrum mercury (Hg) resistance. Equivalent viable plate counts on tryptic soy agar supplemented with either 0 or 25 μM HgCl2 verified the ubiquity of mercury resistance in this microbial environment. Mercury levels in lake water samples measured 1.5 ng L−1; mercury concentrations in fish filets ranged from 81.8 to 1,080 ng g−1 and correlated with fish length. The presence of similar antibiotic and Hg resistance patterns in multiple genera of gastrointestinal microflora supports a growing body of research that multiple selective genes can be transferred horizontally in the presence of an unrelated individual selective pressure. We present data that bioaccumulation of non-point source Hg pollution could be a selective pressure to accumulate both antibiotic and Hg resistant bacteria. PMID:22850694

  14. Influence of pyrolysis conditions on the structure and gasification reactivity of biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; B. Moghtaderi; R. Gupta; T.F. Wall [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2004-11-01

    The physical and chemical structure as well as gasification reactivities of chars generated from several biomass species (i.e. pinus radiata, eucalyptus maculata and sugar cane bagasse) were studied to gain insight into the role of heating rate and pressure on the gasification characteristics of biomass chars. Char samples were generated in a suite of reactors including a wire mesh reactor, a tubular reactor, and a drop tube furnace. Scanning electron microscopy analysis, X-ray diffractometry, digital cinematography and surface area analysis were employed to determine the impact of operating conditions on the char structure. The global gasification reactivities of char samples were also determined for a range of pressures between 1 and 20 bar using pressurised thermogravimetric analysis technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. It was found that under high heating rates the char particles underwent plastic deformation (i.e. melted) developing a structure different to that of the virgin biomass. Pressure was also found to influence the physical and chemical structures of char particles. The difference in the gasification reactivities of biomass chars at pressure was found to correlate well with the effect of pyrolysis pressure on the graphitisation process in the biomass char structure. 29 refs., 18 figs., 2 tabs.

  15. The effect of char structure on burnout during pulverized coal combustion at pressure

    Energy Technology Data Exchange (ETDEWEB)

    Liu, G.; Wu, H.; Benfell, K.E.; Lucas, J.A.; Wall, T.F.

    1999-07-01

    An Australian bituminous coal sample was burnt in a drop tube furnace (DTF) at 1 atm and a pressurized drop tube furnace (PDTF) at 15 atm. The char samples were collected at different burnout levels, and a scanning electron microscope was used to examine the structures of chars. A model was developed to predict the burnout of char particles with different structures. The model accounts for combustion of the thin-walled structure of cenospheric char and its fragmentation during burnout. The effect of pressure on reaction rate was also considered in the model. As a result, approximately 40% and 70% cenospheric char particles were observed in the char samples collected after coal pyrolysis in the DTF and PDTF respectively. A large number of fine particles (< 30 mm) were observed in the 1 atm char samples at burnout levels between 30% and 50%, which suggests that significant fragmentation occurred during early combustion. Ash particle size distributions show that a large number of small ash particles formed during burnout at high pressure. The time needed for 70% char burnout at 15 atm is approximately 1.6 times that at 1 atm under the same temperature and gas environment conditions, which is attributed to the different pressures as well as char structures. The overall reaction rate for cenospheric char was predicted to be approximately 2 times that of the dense chars, which is consistent with previous experimental results. The predicted char burnout including char structures agrees reasonably well with the experimental measurements that were obtained at 1 atm and 15 atm pressures.

  16. Influence of fast pyrolysis conditions on yield and structural transformation of biomass chars

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

    2015-01-01

    this value a similar biomass char yield was obtained. The potassium content affected the char yield stronger than other minerals, while the distribution of the three major biomass constituents (cellulose, hemicellulose, lignin) affected the char yield only to a minor degree. Moreover, it was found...... that the heat treatment temperature had a larger influence on the char yield than the heating rate. Scanning electron microscopy indicated different types of biomass char plasticization influenced by the applied temperatures, heating rates, particle sizes and holding times, except for the rice husk char......Fast pyrolysis of biomass (wood, straw, rice husk) and its major components (cellulose, hemicellulose, lignin) was conducted in a wire mesh reactor. The aim of this study was to understand the influence of temperature (350-1400 ° C), heating rate (10-3000 ° C/s), particle size (0.05-2 mm...

  17. Effects of heat treatment conditions on reactivity of chars in air

    Energy Technology Data Exchange (ETDEWEB)

    Ashu, J. T.; Walker, Jr., P. L.

    1977-09-01

    Reactivities of chars are maximized by keeping heat treatment temperatures as low as possible, minimizing soak time at maximum HTT and maximizing heating rates. It is feasible to use reactivity parameters as a tool for the study of thermal history of carbonaceous materials. Maximum HTT as well as the heating rate used for char preparation seem to be more important parameters in influencing char reactivity than the atmosphere used during preparation. Aging of chars in air following heat treatment at 800/sup 0/C has little or no effect on subsequent char reactivity. The most significant conclusion of this investigation is that rapid heating results in significant increase in char reactivity to air. Surface areas of rapidly heated samples are significantly higher than those prepared at the same temperature using slower heating rates.

  18. Thermal decomposition and gasification of biomass pyrolysis gases using a hot bed of waste derived pyrolysis char.

    Science.gov (United States)

    Al-Rahbi, Amal S; Onwudili, Jude A; Williams, Paul T

    2016-03-01

    Chars produced from the pyrolysis of different waste materials have been investigated in terms of their use as a catalyst for the catalytic cracking of biomass pyrolysis gases during the two-stage pyrolysis-gasification of biomass. The chars were produced from the pyrolysis of waste tyres, refused derived fuel and biomass in the form of date stones. The results showed that the hydrocarbon tar yields decreased significantly with all the char materials used in comparison to the non-char catalytic experiments. For example, at a cracking temperature of 800°C, the total product hydrocarbon tar yield decreased by 70% with tyre char, 50% with RDF char and 9% with biomass date stones char compared to that without char. There was a consequent increase in total gas yield. Analysis of the tar composition showed that the content of phenolic compounds decreased and polycyclic aromatic hydrocarbons increased in the product tar at higher char temperatures.

  19. Catalytic gasification of char from co-pyrolysis of coal and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Wenkui [State key Laboratory of Multi-phase Complex system, the Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China); Graduate University, Chinese Academy of Sciences, Beijing 100080 (China); Song, Wenli; Lin, Weigang [State key Laboratory of Multi-phase Complex system, the Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100080 (China)

    2008-09-15

    The catalytic gasification of char from co-pyrolysis of coal and wheat straw was studied. Alkali metal salts, especially potassium salts, are considered as effective catalysts for carbon gasification by steam and CO{sub 2}, while too expensive for industry application. The herbaceous type of biomass, which has a high content of potassium, may be used as an inexpensive source of catalyst by co-processing with coal. The reactivity of chars from co-pyrolysis of coal and straw was experimentally examined. The chars were prepared in a spout-entrained reactor with different ratios of coal to straw. The gasification characteristics of chars were measured by thermogravimetric analysis (TGA). The co-pyrolysis chars revealed higher gasification reactivity than that of char from coal, especially at high level of carbon conversion. The influence of the alkali in the char and the pyrolysis temperature on the reactivity of co-pyrolysis char was investigated. The experimental results show that the co-pyrolysis char prepared at 750 C have the highest alkali concentration and reactivity. (author)

  20. Effect of pyrolysis pressure and heating rate on radiata pine char structure and apparent gasification reactivity

    Energy Technology Data Exchange (ETDEWEB)

    E. Cetin; R. Gupta; B. Moghtaderi [University of Newcastle, Callaghan, NSW (Australia). Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, School of Engineering

    2005-07-01

    The knowledge of biomass char gasification kinetics has considerable importance in the design of advanced biomass gasifiers, some of which operate at high pressure. The char gasification kinetics themselves are influenced by char structure. In this study, the effects of pyrolysis pressure and heating rate on the char structure were investigated using scanning electron microscopy (SEM) analysis, digital cinematography, and surface area analysis. Char samples were prepared at pressures between 1 and 20 bar, temperatures ranging from 800 to 1000{degree}C, and heating rates between 20 and 500{degree}C/s. Our results indicate that pyrolysis conditions have a notable impact on the biomass char morphology. Pyrolysis pressure, in particular, was found to influence the size and the shape of char particles while high heating rates led to plastic deformation of particles (i.e. melting) resulting in smooth surfaces and large cavities. The global gasification reactivities of char samples were also determined using thermogravimetric analysis (TGA) technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. 22 refs., 8 figs., 2 tabs.

  1. [Configuration of pyrolytic chars from waste tires in fluidized bed reactor].

    Science.gov (United States)

    Jin, Yu-qi; Yan, Jian-hua; Gu, Jie-yuan; Cen, Ke-fa

    2004-11-01

    With the fluidized bed as main reactor, the configuration of chars of waste tire was investigated. The change of specific surface area, porosity and specific pore volume of chars received at various temperature, diameter of bed materials and superficial fluidization number was mainly researched. The specific surface area and porosity of chars had the peak value at 650 degrees C or 750 degrees C, which showed there exists the best pyrolysis temperature from the angle of char quality and it will decrease with smaller diameter of bed materials, 0.135-0.304mm. The porosity of chars decreases with the fluidization number increasing. The change tendency of the specific surface area of chars with the fluidization number is correlated with the pyrolysis temperature. At 550 degrees C the specific surface area of chars decreases with the fluidization number increasing, while at 650 degrees C the other way round. The change tendency of the specific pore volume of chars with the temperature is correlated with the diameter of bed materials. With larger bed materials (0.304-0.4mm), the specific pore volume of chars rises at fisrt, then decreases with the temperature increasing, and with smaller bed materials, it decreases with the temperature increasing.

  2. The thermal history of char as disclosed by carbon isotope ratios

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ambus, Per; Ahrenfeldt, Jesper

    In laboratory experiments, biomass char was produced under controlled conditions using wood chips from French pinewood. Different char qualities were obtained by pyrolysing the biomass at similar heating rates with end-temperatures ranging from 250 to 1000 o C. The char was analysed by flash...... pyrolysis and isotope ratio mass spectrometry. The results demonstrate that the temperature history of the char is reflected in the fine variation of carbon isotopes. The compound classes responsible for the variation were identified. Key words: Isotope ratio, flash pyrolysis, hot gas cleaning...

  3. Activated carbon from char obtained from vacuum pyrolysis of teak sawdust: pore structure development and characterization.

    Science.gov (United States)

    Ismadji, S; Sudaryanto, Y; Hartono, S B; Setiawan, L E K; Ayucitra, A

    2005-08-01

    The preparation of activated carbon from vacuum pyrolysis char of teak sawdust was studied and the results are presented in this paper. The effects of process variables such as temperature and activation time on the pore structure of activated carbons were studied. The activated carbon prepared from char obtained by vacuum pyrolysis has higher surface area and pore volume than that from atmospheric pyrolysis char. The BET surface area and pore volume of activated carbon prepared from vacuum pyrolysis char were 1150 m2/g and 0.43 cm3/g, respectively.

  4. Particle behavior and char burnout mechanisms under pressurized combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C.M.; Spliethoff, H.; Hein, K.R.G.

    1999-07-01

    Combined cycle systems with coal-fired gas turbines promise highest cycle efficiencies for this fuel. Pressurized pulverized coal combustion, in particular, yields high cycle efficiencies due to the high flue gas temperatures possible. The main problem, however, is to ensure a flue gas clean enough to meet the high gas turbine standards with a dirty fuel like coal. On the one hand, a profound knowledge of the basic chemical and physical processes during fuel conversion under elevated pressures is required whereas on the other hand suitable hot gas cleaning systems need to be developed. The objective of this work was to provide experimental data to enable a detailed description of pressurized coal combustion processes. A series of experiments were performed with two German hvb coals, Ensdorf and Goettelborn, and one German brown coal, Garzweiler, using a semi-technical scale pressurized entrained flow reactor. The parameters varied in the experiments were pressure, gas temperature and bulk gas oxygen concentration. A two-color pyrometer was used for in-situ determination of particle surface temperatures and particle sizes. Flue gas composition was measured and solid residue samples taken and subsequently analyzed. The char burnout reaction rates were determinated varying the parameters pressure, gas temperature and initial oxygen concentration. Variation of residence time was achieved by taking the samples at different points along the reaction zone. The most influential parameters on char burnout reaction rates were found to be oxygen partial pressure and fuel volatile content. With increasing pressure the burn-out reactions are accelerated and are mostly controlled by product desorption and pore diffusion being the limiting processes. The char burnout process is enhanced by a higher fuel volatile content.

  5. One kind of technology on producing char without pollution

    Energy Technology Data Exchange (ETDEWEB)

    Yin Chengxu [Kunming Inst. of Coal Science (China). Dept. of Coal Chemical Engineering

    1997-12-31

    This paper introduces one kind of technology on continually producing char without pollution. The capacity of each furnace is treating 5000 tons of brown coal annually. The production has been kept running for one year. Its products are high quality reducing agent for the iron alloy, calcium carbide and yellow phosphorus etc. This technology has the advantages of less investment, easy to manage, low energy consumption and environmental-friendly. The abundant heat could be utilized to produce steam for thermal supply and power generation. (orig.)

  6. Preparation of porous bio-char and activated carbon from rice husk by leaching ash and chemical activation.

    Science.gov (United States)

    Ahiduzzaman, Md; Sadrul Islam, A K M

    2016-01-01

    Preparation porous bio-char and activated carbon from rice husk char study has been conducted in this study. Rice husk char contains high amount silica that retards the porousness of bio-char. Porousness of rice husk char could be enhanced by removing the silica from char and applying heat at high temperature. Furthermore, the char is activated by using chemical activation under high temperature. In this study no inert media is used. The study is conducted at low oxygen environment by applying biomass for consuming oxygen inside reactor and double crucible method (one crucible inside another) is applied to prevent intrusion of oxygen into the char. The study results shows that porous carbon is prepared successfully without using any inert media. The adsorption capacity of material increased due to removal of silica and due to the activation with zinc chloride compared to using raw rice husk char. The surface area of porous carbon and activated carbon are found to be 28, 331 and 645 m(2) g(-1) for raw rice husk char, silica removed rice husk char and zinc chloride activated rice husk char, respectively. It is concluded from this study that porous bio-char and activated carbon could be prepared in normal environmental conditions instead of inert media. This study shows a method and possibility of activated carbon from agro-waste, and it could be scaled up for commercial production.

  7. Reaction Kinetic Equation for Char Combustion of Underground Coal Gasification

    Institute of Scientific and Technical Information of China (English)

    YU Hong-guan; YANG Lan-he; FENG Wei-min; LIU Shu-qin; SONG Zhen-qi

    2006-01-01

    Based on the quasi-steady-state approximation, the dynamic equation of char combustion in the oxidation zone of underground coal gasification (UCG) was derived. The parameters of the dynamic equation were determined at 900℃ using a thermo-gravimetric (TG) analyzer connected to a flue gas analyzer and this equation. The equation was simplified for specific coals, including high ash content, low ash content, and low ash fusibility ones. The results show that 1) the apparent reaction rate constant increases with an increase in volatile matter value as dry ash-free basis, 2) the effective coefficient of diffusion decreases with an increase in ash as dry basis, and 3) the mass transfer coefficient is independent of coal quality on the whole. The apparent reaction rate constant, mass-transfer coefficient and effective coefficient of diffusion of six char samples range from 7.51×104 m/s to 8.98×104 m/s, 3.05×106 m/s to 3.23×106 m/s and 5.36×106 m2/s to 8.23×106 m2/s at 900℃, respectively.

  8. Suspension Combustion of Wood: Influence of Pyrolysis Conditions on Char Yield, Morphology, and Reactivity

    DEFF Research Database (Denmark)

    Dall'Ora, Michelangelo; Jensen, Peter Arendt; Jensen, Anker Degn

    2008-01-01

    Chars from pine and beech wood were produced by fast pyrolysis in an entrained flow reactor and by slow pyrolysis in a thermogravimetric analyzer. The influence of pyrolysis temperature, heating rate and particle size on char yield and morphology was investigated. The applied pyrolysis temperatur...

  9. Mercury adsorption of modified mulberry twig chars in a simulated flue gas.

    Science.gov (United States)

    Shu, Tong; Lu, Ping; He, Nan

    2013-05-01

    Mulberry twig chars were prepared by pyrolysis, steam activation and impregnation with H2O2, ZnCl2 and NaCl. Textural characteristics and surface functional groups were performed using nitrogen adsorption and FTIR, respectively. Mercury adsorption of different modified MT chars was investigated in a quartz fixed-bed absorber. The results indicated that steam activation and H2O2-impregnation can improve pore structure significantly and H2O2-impregnation and chloride-impregnation promote surface functional groups. However, chloride-impregnation has adverse effect on pore structure. Mercury adsorption capacities of impregnated MT chars with 10% or 30% H2O2 are 2.02 and 1.77 times of steam activated MT char, respectively. Mercury adsorption capacity of ZnCl2-impregnated MT char increase with increasing ZnCl2 content and is better than that of NaCl-impregnated MT char at the same chloride content. The modified MT char (MT873-A-Z5) prepared by steam activation following impregnation with 5% ZnCl2 exhibits a higher mercury adsorption capacity (29.55 μg g(-1)) than any other MT chars.

  10. Removal of lead (Pb2+) from aqueous medium by using chars from co-pyrolysis.

    Science.gov (United States)

    Bernardo, Maria; Mendes, Sandra; Lapa, Nuno; Gonçalves, Margarida; Mendes, Benilde; Pinto, Filomena; Lopes, Helena; Fonseca, Isabel

    2013-11-01

    The effectiveness of chars from the co-pyrolysis of pine, used tires and plastic wastes for the removal of lead (Pb(2+)) from aqueous medium, was investigated. The chars were predominantly of macroporous nature, but the introduction of tires in the pyrolysis feedstock enhanced their mesoporous content as well as surface area. Pb(2+) sorption with the chars was a slow and unstable process in which sorption-desorption seems to be competing. The highest Pb(2+) removal (88%) was attained by the char resulting from the pyrolysis of a mixture composed by equal mass ratios of used tires and plastics, at 48 h of contact time. This char was also the one with the overall better performance for Pb(2+) sorption, achieving almost 100% of Pb(2+) removal on the study of the effect of adsorbent dose. Mixing the three raw materials for pyrolysis had no advantage for the resulting char concerning the removal efficiency of Pb(2+). The sorption mechanisms varied according to the pyrolysis feedstock: in chars from feedstock with pine, chemisorption involving complexation with oxygenated surface functional groups followed by cation exchange was the presumable mechanism. In tire rubber derived chars, cation exchange with Ca(2+), K(+), and Zn(2+) played the major role on Pb(2+) sorption.

  11. Bio-char derived from sewage sludge by liquefaction: Characterization and application for dye adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Leng, Lijian [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Yuan, Xingzhong, E-mail: yxz@hnu.edu.cn [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Huang, Huajun [School of Land Resources and Environment, Jiangxi Agricultural University, Nanchang 330045 (China); Shao, Jianguang; Wang, Hou [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China); Chen, Xiaohong [School of Business, Central South University, Changsha 410083 (China); Zeng, Guangming [College of Environmental Science and Engineering, Hunan University, Changsha 410082 (China); Key Laboratory of Environment Biology and Pollution Control, Hunan University, Ministry of Education, Changsha 410082 (China)

    2015-08-15

    Graphical abstract: - Highlights: • SS liquefaction bio-chars were effective on MG and MB removal from aqueous. • MG adsorption capacity depended strongly on carboxylic and phenolic groups. • Metal release accounted for nearly 30% of the total MG adsorbed on bio-chars. • Acetone and low temperature favor effective adsorbent production by liquefaction. - Abstract: Bio-chars produced by liquefaction of sewage sludge with methanol, ethanol, or acetone as the solvent at 260–380 °C were characterized in terms of their elemental composition, thermogravimetric characteristics, surface area and pore size distribution, and oxygen-containing functional groups composition. The surface area and total volume of the bio-chars were low, but the contents of oxygen-containing functional groups were high. The bio-chars were effective on Malachite green (MG) and Methylene blue (MB) removal from aqueous solution. The MG adsorption equilibrium data showed excellent fit to the Langmuir model and the kinetic data fitted well to the Pseudo-second-order model. Thermodynamic investigations indicated that MG adsorption on bio-char was spontaneous and endothermic. The MG adsorption mechanism appears to be associated with cation release and functional group participation. Additionally, liquefaction of SS with acetone as the solvent at low temperature (280 °C) would favor the production of bio-char adsorbent in terms of bio-char yield and MG and MB adsorption capacity.

  12. Electron paramagnetic resonance and dynamic nuclear polarization of char suspensions: surface science and oximetry

    DEFF Research Database (Denmark)

    Clarkson, R B; Odintsov, B M; Ceroke, P J

    1998-01-01

    ; they can be calibrated and used for oximetry. Biological stability and low toxicity make chars good sensors for in vivo measurements. Scalar and dipolar interactions of water protons at the surfaces of chars may be utilized to produce dynamic nuclear polarization (DNP) of the nuclear spin population...

  13. Thermogravimetric Analysis of Char Waste from the Air Gasification of Empty Fruit Bunch Briquette.

    Directory of Open Access Journals (Sweden)

    Nyakuma Bemgba Bevan

    2014-07-01

    Full Text Available The thermal decomposition behavior of char waste produced from the air gasification of Empty Fruit Bunch (EFB briquette was examined using thermogravimetric analysis (TGA. A comparison between the thermal decomposition behavior of char waste and EFB briquette is also presented. The results indicate that the char waste produced decreased from 22 % to 18 % with increasing temperature from 600 °C to 700 °C during gasification. This is due to the effect of high temperatures on the primary char decomposition reactions. It was observed that char degradation occurs in two steps; char degradation I & II with weight losses of 17 % and 32 % respectively. This showed that only ~ 50 % char was decomposed during thermal analysis, hence higher temperatures are required to ensure complete decomposition. The TGA curve for EFB briquette showed that complete thermal decomposition of EFB briquette occurs in four stages namely; drying, devolatization, reduction and char degradation. The most significant weight loss 2.51 mg or 49.31 % occurred during devolatization.

  14. Production and Characterization of Bio-Char from the Pyrolysis of Empty Fruit Bunches

    Directory of Open Access Journals (Sweden)

    Mohamad A. Sukiran

    2011-01-01

    Full Text Available Problem statement: The palm oil industry generates an abundance of oil palm biomass such as the Empty Fruit Bunch (EFB, shell, frond, trunk and Palm Oil Mill Effluent (POME. For 88 million tones of Fresh Fruit Bunch (FFB processed in 2008, the amount of oil palm biomass was more than 26 million tones. Studies about production of bio-char from oil palm biomass are still lacking in Malaysia. So, this study was aimed to: (i determine the effect of pyrolysis temperatures on bio-char yield (ii characterize the bio-char obtained under different pyrolysed temperatures. Approach: In this study, pyrolysis of EFB was conducted using a fluidized fixed bed reactor. The effect of pyrolysis temperatures on bio-char yield was investigated. The pyrolysis temperature used ranged from 300-700°C. The elemental analysis, calorific value, surface area and total pore volume of the bio-char were determined. Results: The highest bio char yield of 41.56% was obtained at an optimum pyrolysis temperature of 300°C with particle size of 91-106 μm and the heating rate of 30°C min-1. The calorific values of bio-char ranged from 23-26 MJ kg-1. Conclusion: It was found that the bio-char products can be characterized as carbon rich, high calorific value and potential solid biofuels.

  15. Bioenergetic evaluation of diel vertical migration by bull trout (Salvelinus confluentus) in a thermally stratified reservoir

    Science.gov (United States)

    Eckmann, Madeleine; Dunham, Jason; Connor, Edward J.; Welch, Carmen A.

    2016-01-01

    Many species living in deeper lentic ecosystems exhibit daily movements that cycle through the water column, generally referred to as diel vertical migration (DVM). In this study, we applied bioenergetics modelling to evaluate growth as a hypothesis to explain DVM by bull trout (Salvelinus confluentus) in a thermally stratified reservoir (Ross Lake, WA, USA) during the peak of thermal stratification in July and August. Bioenergetics model parameters were derived from observed vertical distributions of temperature, prey and bull trout. Field sampling confirmed that bull trout prey almost exclusively on recently introduced redside shiner (Richardsonius balteatus). Model predictions revealed that deeper (>25 m) DVMs commonly exhibited by bull trout during peak thermal stratification cannot be explained by maximising growth. Survival, another common explanation for DVM, may have influenced bull trout depth use, but observations suggest there may be additional drivers of DVM. We propose these deeper summertime excursions may be partly explained by an alternative hypothesis: the importance of colder water for gametogenesis. In Ross Lake, reliance of bull trout on warm water prey (redside shiner) for consumption and growth poses a potential trade-off with the need for colder water for gametogenesis.

  16. Allantoinase in lake trout (Salvelinus namaycush): in vitro effects of PCBs, DDT and metals

    Science.gov (United States)

    Passino, Dora R. May; Cotant, Carol A.

    1979-01-01

    1. Allantoinase, an enzyme in the purine-urea cycle, was found in livers of Salvelinus namaycush (Osteichthyes: Salmoniformes). 2. The enzyme was active from pH 6.6 to 8.2 at 37°C and from pH 7.4 to 9.0 at 10°C and had an Arrhenius energy of activation of 11.0 kcal/mol and a temperature quotient of 2.0. The Km of the enzyme homogenate was 8.4 mM allantoin. 3. The concentration of inorganic metals at which 50% inhibition occurred during in vitro exposure were 6.0 mg/l Cu2+, 6.7 mg/l Cd2+, 34 mg/l Hg2+ and 52 mg/l Pb2+. The in vitro sensitivity to PCBs, DDT and DDE and kinetics in the presence of metals were determined. 4. Allantoinase activity was negatively correlated with body length for fish from Lake Michigan but not from Lake Superior or the laboratory.

  17. Sexual difference in mercury concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

    Science.gov (United States)

    Madenjian, C.P.; Keir, M.J.; Whittle, D.M.

    2011-01-01

    We determined total mercury (Hg) concentrations in 50 female lake trout (Salvelinus namaycush) and 69 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). Results showed that, on average, males were 8% higher in Hg concentration than females in Lake Ontario. We also used bioenergetics modeling to determine whether a sexual difference in gross growth efficiency (GGE) could explain the observed sexual difference in Hg concentrations. According to the bioenergetics modeling results, male GGE was about 3% higher than female GGE, on average. Although the bioenergetics modeling could not explain the higher Hg concentrations exhibited by the males, a sexual difference in GGE remained a plausible explanation for the sexual difference in Hg concentrations of the lake trout. In an earlier study, male lake trout from Lake Ontario were found to be 22% higher in polychlorinated biphenyl (PCB) concentration than females from Lake Ontario. Thus, although males were higher in both Hg and PCB concentrations, the degree of the sexual difference in concentration varied between the two contaminants. Further research on sexual differences in Hg excretion rates and Hg direct uptake rates may be needed to resolve the disparity in results between the two contaminants.

  18. Spawning site fidelity of wild and hatchery lake trout (Salvelinus namaycush) in northern Lake Huron

    Science.gov (United States)

    Binder, Thomas; Riley, Stephen C.; Holbrook, Christopher; Hansen, Michael J.; Bergstedt, Roger A.; Bronte, Charles R.; He, Ji; Krueger, Charles C.

    2016-01-01

    Fidelity to high-quality spawning sites helps ensure that adults repeatedly spawn at sites that maximize reproductive success. Fidelity is also an important behavioural characteristic to consider when hatchery-reared individuals are stocked for species restoration, because artificial rearing environments may interfere with cues that guide appropriate spawning site selection. Acoustic telemetry was used in conjunction with Cormack–Jolly–Seber capture–recapture models to compare degree of spawning site fidelity of wild and hatchery-reared lake trout (Salvelinus namaycush) in northern Lake Huron. Annual survival was estimated to be between 77% and 81% and did not differ among wild and hatchery males and females. Site fidelity estimates were high in both wild and hatchery-reared lake trout (ranging from 0.78 to 0.94, depending on group and time filter), but were slightly lower in hatchery-reared fish than in wild fish. The ecological implication of the small difference in site fidelity between wild and hatchery-reared lake trout is unclear, but similarities in estimates suggest that many hatchery-reared fish use similar spawning sites to wild fish and that most return to those sites annually for spawning.

  19. Hiding in Plain Sight: A Case for Cryptic Metapopulations in Brook Trout (Salvelinus fontinalis.

    Directory of Open Access Journals (Sweden)

    David C Kazyak

    Full Text Available A fundamental issue in the management and conservation of biodiversity is how to define a population. Spatially contiguous fish occupying a stream network have often been considered to represent a single, homogenous population. However, they may also represent multiple discrete populations, a single population with genetic isolation-by-distance, or a metapopulation. We used microsatellite DNA and a large-scale mark-recapture study to assess population structure in a spatially contiguous sample of Brook Trout (Salvelinus fontinalis, a species of conservation concern. We found evidence for limited genetic exchange across small spatial scales and in the absence of barriers to physical movement. Mark-recapture and stationary passive integrated transponder antenna records demonstrated that fish from two tributaries very seldom moved into the opposite tributary, but movements between the tributaries and mainstem were more common. Using Bayesian genetic clustering, we identified two genetic groups that exhibited significantly different growth rates over three years of study, yet survival rates were very similar. Our study highlights the importance of considering the possibility of multiple genetically distinct populations occurring within spatially contiguous habitats, and suggests the existence of a cryptic metapopulation: a spatially continuous distribution of organisms exhibiting metapopulation-like behaviors.

  20. Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

    Science.gov (United States)

    Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.

    2010-01-01

    We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

  1. Net trophic transfer efficiencies of polychlorinated biphenyl congeners to lake trout (Salvelinus namaycush) from its prey

    Science.gov (United States)

    Madenjian, Charles P.; David, Solomon R.; Rediske, Richard R.; O’Keefe, James P.

    2012-01-01

    Lake trout (Salvelinus namaycush) were fed bloater (Coregonus hoyi) in eight laboratory tanks over a 135-d experiment. At the start of the experiment, four to nine fish in each tank were sacrificed, and the concentrations of 75 polychlorinated biphenyl (PCB) congeners within these fish were determined. Polychlorinated biphenyl congener concentrations were also determined in the 10 lake trout remaining in each of the eight tanks at the end of the experiment as well as in the bloater fed to the lake trout. Each lake trout was weighed at the start and the end of the experiment, and the amount of food eaten by the lake trout was recorded. Using these measurements, net trophic transfer efficiency (γ) from the bloater to the lake trout in each of the eight tanks was calculated for each of the 75 congeners. Results showed that γ did not vary significantly with the degree of chlorination of the PCB congeners, and γ averaged 0.66 across all congeners. However,γ did show a slight, but significant, decrease as logKOW increased from 6.0 to 8.2. Activity level of the lake trout did not have a significant effect on γ.

  2. Effects of retorting factors on combustion properties of shale char. 3. Distribution of residual organic matters.

    Science.gov (United States)

    Han, Xiangxin; Jiang, Xiumin; Cui, Zhigang; Liu, Jianguo; Yan, Junwei

    2010-03-15

    Shale char, formed in retort furnaces of oil shale, is classified as a dangerous waste containing several toxic compounds. In order to retort oil shale to produce shale oil as well as treat shale char efficiently and in an environmentally friendly way, a novel kind of comprehensive utilization system was developed to use oil shale for shale oil production, electricity generation (shale char fired) and the extensive application of oil shale ash. For exploring the combustion properties of shale char further, in this paper organic matters within shale chars obtained under different retorting conditions were extracted and identified using a gas chromatography-mass spectrometry (GC-MS) method. Subsequently, the effects of retorting factors, including retorting temperature, residence time, particle size and heating rate, were analyzed in detail. As a result, a retorting condition with a retorting temperature of 460-490 degrees C, residence time of circulating fluidized bed technology with fractional combustion.

  3. PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST

    Directory of Open Access Journals (Sweden)

    Xian-Hua Wang

    2009-08-01

    Full Text Available Pine sawdust pyrolysis was carried out respectively using microwave and conventional electrical heating at different temperatures in order to understand the properties of pyrolytic products from microwave pyrolysis of biomass. Less char material was obtained by microwave pyrolysis compared to conventional heating at the same temperature. While comparing the components of the pyrolytic gases, it was revealed that the microwave pyrolysis gas usually had higher H2 and CO contents and lower CH4 and CO2 contents than those obtained by conventional pyrolysis at the same temperature. The texture analysis results of the microwave pyrolysis chars showed that the chars would melt and the pores would shrink at high temperatures, and hence, the specific surface areas of the chars decreased with increasing temperature. Similarly, the reactivity of the char was remarkably reduced when the microwave pyrolysis temperature exceeded 600°C.

  4. Investigation of char strength and expansion properties of an intumescent coating exposed to rapid heating rates

    DEFF Research Database (Denmark)

    Nørgaard, Kristian Petersen; Dam-Johansen, Kim; Català, Pere

    2013-01-01

    An efficient and space saving method for passive fire protection is the use of intumescent coatings, which swell when exposed to heat, forming an insulating char layer on top of the virgin coating. Although the temperature curves related to so-called cellulosic fires are often referred to as slow...... heating curves, special cases where the protective char is mechanically damaged and partly removed can cause extremely fast heating of the coating. This situation, for a solvent based intumescent coating, is simulated using direct insertion of free films into a muffle oven. The char formed is evaluated......, char properties, measured at room temperature, were dependent on the preceding storage conditions (in air or in a desiccator). The char was found to have the highest mechanical strength against compression in the outer crust facing the heat source. For thin (147μm) free coating films, a tendency...

  5. Effect of CO2 gasification reaction on oxycombustion of pulverized coal char.

    Energy Technology Data Exchange (ETDEWEB)

    Molina, Alejandro (Universidad Nacional de Colombia, Medellin, Colombia); Hecht, Ethan S.; Shaddix, Christopher R.; Haynes, Brian S. (University of Sydney, New South Wales, Australia)

    2010-07-01

    For oxy-combustion with flue gas recirculation, as is commonly employed, it is recognized that elevated CO{sub 2} levels affect radiant transport, the heat capacity of the gas, and other gas transport properties. A topic of widespread speculation has concerned the effect of the CO{sub 2} gasification reaction with coal char on the char burning rate. To give clarity to the likely impact of this reaction on the oxy-fuel combustion of pulverized coal char, the Surface Kinetics in Porous Particles (SKIPPY) code was employed for a range of potential CO{sub 2} reaction rates for a high-volatile bituminous coal char particle (130 {micro}m diameter) reacting in several O{sub 2} concentration environments. The effects of boundary layer chemistry are also examined in this analysis. Under oxygen-enriched conditions, boundary layer reactions (converting CO to CO{sub 2}, with concomitant heat release) are shown to increase the char particle temperature and burning rate, while decreasing the O{sub 2} concentration at the particle surface. The CO{sub 2} gasification reaction acts to reduce the char particle temperature (because of the reaction endothermicity) and thereby reduces the rate of char oxidation. Interestingly, the presence of the CO{sub 2} gasification reaction increases the char conversion rate for combustion at low O{sub 2} concentrations, but decreases char conversion for combustion at high O{sub 2} concentrations. These calculations give new insight into the complexity of the effects from the CO{sub 2} gasification reaction and should help improve the understanding of experimentally measured oxy-fuel char combustion and burnout trends in the literature.

  6. Coal pyrolysis and char burnout under conventional and oxy-fuel conditions

    Energy Technology Data Exchange (ETDEWEB)

    Al-Makhadmeh, L.; Maier, J.; Scheffknecht, G. [Stuttgart Univ. (Germany). Institut fuer Verfahrenstechnik und Dampfkesselwesen

    2009-07-01

    Coal utilization processes such as combustion or gasification generally involve several steps i.e., the devolatilization of organic materials, homogeneous reactions of volatile matter with the reactant gases, and heterogeneous reactions of the solid (char) with the reactant gases. Most of the reported work about coal pyrolysis and char burnout were performed at low temperatures under environmental conditions related to the air firing process with single particle tests. In this work, coal combustion under oxy-fuel conditions is investigated by studying coal pyrolysis and char combustion separately in practical scales, with the emphasis on improving the understanding of the effect of a CO{sub 2}-rich gas environment on coal pyrolysis and char burnout. Two coals, Klein Kopje a medium volatile bituminous coal and a low-rank coal, Lausitz coal were used. Coal pyrolysis in CO{sub 2} and N{sub 2} environments were performed for both coals at different temperatures in an entrained flow reactor. Overall mass release, pyrolysis gas concentrations, and char characterization were performed. For char characterization ultimate analysis, particle size, and BET surface area were measured. Chars for both coals were collected at 1150 C in both CO{sub 2} and N{sub 2} environments. Char combustion was performed in a once-through 20 kW test facility in O{sub 2}/CO{sub 2} and O{sub 2}/N{sub 2} atmospheres. Besides coal quality, oxygen partial pressure was chosen as a variable to study the effect of the gas environment on char burnout. In general, it is found that the CO{sub 2} environment and coal rank have a significant effect on coal pyrolysis and char burnout. (orig.)

  7. 煤焦与生物质焦共气化反应特性研究%Co-gasification properties of coal char and biomass char

    Institute of Scientific and Technical Information of China (English)

    任海君; 张永奇; 房倚天; 王洋

    2012-01-01

    以晋城无烟煤和生物质(肉骨粉Meat and Bone Meal∶MBM)为原料,在固定床上采用快速热解法制备了煤和生物质焦样.采用扫描电子显微镜结合X射线能谱分析仪(SEM-EDX)分析了煤焦和MBM焦的表面形态和组成;在热天平上采用等温热重法进行了煤焦/MBM焦混合物的水蒸气气化研究.实验结果表明,煤/MBM焦混合物的共气化实验碳转化率高于两者不存在协同作用时的计算值,这是由于MBM焦含有较多的Na、Ca等元素,这些物质对煤焦气化起到了催化作用.当对MBM焦进行脱灰处理后,其气化反应性显著下降.混合物中MBM焦的质量分数在20%~80%时,随着MBM焦含量的增加,混合物中的煤焦反应性相应提高.%An experimental study on the co-gasification property of coal char and biomass char with steam was performed in a thermogravimetric analyzer (TGA). The coal tested was Jincheng anthracite (JC) , and the biomass was meat and bone meal ( MBM). The chars were prepared by fast pyrolysis of coal and MBM individually. The morphology and composition of chars were analyzed by scanning electron microscope (SEM) equipped with an energy-dispersive X-ray analyzer (EDX). The results show that the co-gasification rate of JC/ MBM chars mixture is higher than that of results expected from independent behavior. The high content of Ca and Na in MBM char plays a catalytic effect during co-gasification. After washing with acid, the reactivity of MBM char declines markedly. The gasification rate of coal char in JC/MBM chars mixture increases with increasing MBM char content in rang of 20% ~ 80%.

  8. Properties of gasification-derived char and its utilization for catalytic tar reforming

    Science.gov (United States)

    Qian, Kezhen

    Char is a low-value byproduct of biomass gasification and pyrolysis with many potential applications, such as soil amendment and the synthesis of activated carbon. The overall goal of the proposed research was to develop novel methods to use char derived from gasification for high-value applications in syngas conditioning. The first objective was to investigate effects of gasification condition and feedstock on properties of char derived from fluidized bed gasification. Results show that the surface areas of most of the char were 1--10 m 2/g and increased as the equivalence ratio increased. Char moisture and fixed carbon contents decreased while ash content increased as equivalence ratio increased. The next objective was to study the properties of sorghum and red cedar char derived from downdraft gasifier. Red cedar char contained more aliphatic carbon and o-alkyl carbon than sorghum char. Char derived from downdraft gasification had higher heating values and lower ash contents than char derived from fluidized bed gasification. The gasification reactivity of red cedar char was higher than that of sorghum char. Then, red cedar char based catalysts were developed with different preparation method to reform toluene and naphthalene as model tars. The catalyst prepared with nickel nitrate was found to be better than that with nickel acetate. The nickel particle size of catalyst impregnated with nickel nitrate was smaller than that of catalyst impregnated with nickel acetate. The particle size of catalyst impregnated with nickel acetate decreased by hydrazine reduction. The catalyst impregnated with nickel nitrate had the highest toluene removal efficiency, which was 70%--100% at 600--800 °C. The presence of naphthalene in tar reduced the catalyst efficiency. The toluene conversion was 36--99% and the naphthalene conversion was 37%--93% at 700--900 °C. Finally, effects of atmosphere and pressure on catalytic reforming of lignin-derived tars over the developed catalyst

  9. The removal of reactive dyes using high-ash char

    Directory of Open Access Journals (Sweden)

    Moreira R.F.P.M.

    2001-01-01

    Full Text Available The thermodynamics and kinetics of adsorption of reactive dyes on high-ash char was studied. Equilibrium data were obtained using the static method with controlled agitation at temperatures in the range of 30 to 60ºC. The Langmuir isotherm model was used to describe the equilibrium of adsorption, and the equilibrium parameters, R L, in the range of 0 to 1 indicate favorable adsorption. The amount of dye adsorbed increased as temperature increased from 30 to 40ºC, but above 40ºC the increase in temperature resulted in a decrease in the amount of dye adsorbed. The kinetic data presented are for controlled agitation at 50 rpm and constant temperature with dye concentrations in the range of 10 ppm to50 ppm. The film mass transfer coefficient, Kf, and the effective diffusivity inside the particle, De, were fitted to the experimental data. The results indicate that internal diffusion governs the adsorption rate.

  10. Effect of pressure on combustion of char in fluidised beds

    Energy Technology Data Exchange (ETDEWEB)

    Turnbull, E.; Blackshaw, H.W.; Davidson, J.F.; Goodyer, P.T.Y.; Hopes, R.B.; Kossakowski, E.R.

    1984-07-01

    Measurements of burn-out time are reported, for 0.25-1.7 mm carbon particles in an air-fluidised 100 mm dia bed of sand at pressures up to 17 bar absolute and bed temperatures of 1023-1173 K. A variety of carbons was used including (i) coke (ii) chars formed from coals of different ranks: thus the carbons had various porosities and surface areas. The effect of increased pressure is to increase the combustion rate, because of the higher oxygen concentration which accelerates the chemical reactions of combustion. On the other hand, pressure has virtually no influence on diffusion of oxygen towards a burning particle, because the higher oxygen concentration is offset by a proportionately lower diffusion coefficient. The overall effect is that as pressure increases, the chemical rate controlling steps become less important, so at very high pressure, combustion is diffusion controlled.

  11. Organic structure and possible origin of ancient charred paddies at Chuodun Site in southern China

    Institute of Scientific and Technical Information of China (English)

    HU LinChao; LI Xia; LIU BenDing; GU Min; DAI JingYu

    2009-01-01

    A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixthexcavation at Chuodun Site and are assigned to the Majiabang culture (7-6 ka BP). To understand their formation mechanism, the ancient charred paddies were compared to modern paddies using FT-IR spectrum and thermaogravimetric analysis. At the same time, modern charred paddies were made in helium by the laboratory method, and the structural characteristics of them and the ancient ones were revealed using CP/MAS-13C-NMR. Our results show there are more aromatic moieties in ancient charred paddies compared to modern paddies. The aliphatic components of modern charred paddies decreasecontinuously, accompanied by the accumulation of aromatic components, when the duration and temperature of oxidation increase, and the structure buildings of modern charred paddies are more similar to ancient ones. Given the planting manner of paddies during Majiabang culture period, these ancient charred paddies might be a result of the original farming mode involving fire.

  12. Organic structure and possible origin of ancient charred paddies at Chuodun Site in southern China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A number of ancient charred paddies with a 14C dating of about 5900 a BP were recovered in the sixth excavation at Chuodun Site and are assigned to the Majiabang culture(7-6 ka BP).To understand their formation mechanism,the ancient charred paddies were compared to modern paddies using FT-IR spectrum and thermaogravimetric analysis.At the same time,modern charred paddies were made in helium by the laboratory method,and the structural characteristics of them and the ancient ones were revealed using CP/MAS-13C-NMR.Our results show there are more aromatic moieties in ancient charred paddies compared to modern paddies.The aliphatic components of modern charred paddies decrease continuously,accompanied by the accumulation of aromatic components,when the duration and temperature of oxidation increase,and the structure buildings of modern charred paddies are more similar to ancient ones.Given the planting manner of paddies during Majiabang culture period,these ancient charred paddies might be a result of the original farming mode involving fire.

  13. Physico-chemical properties of chars obtained in the co-pyrolysis of waste mixtures.

    Science.gov (United States)

    Bernardo, M; Lapa, N; Gonçalves, M; Mendes, B; Pinto, F; Fonseca, I; Lopes, H

    2012-06-15

    The present work aims to perform a multistep upgrading of chars obtained in the co-pyrolysis of PE, PP and PS plastic wastes, pine biomass and used tires. The quality of the upgraded chars was evaluated by measuring some of their physico-chemical properties in order to assess their valorisation as adsorbents' precursors. The crude chars were submitted to a sequential solvent extraction with organic solvents of increasing polarity (hexane, mixture 1:1 v/v hexane:acetone and acetone) followed by an acidic demineralization procedure with 1M HCl solution. The results obtained showed that the upgrading treatment allow the recovery of 63-81% of the pyrolysis oils trapped in the crude chars and a reduction in the char's ash content in the range of 64-86%. The textural and adsorption properties of the upgraded chars were evaluated and the results indicate that the chars are mainly mesoporous and macroporous materials, with adsorption capacities in the range of 3.59-22.2 mg/g for the methylene blue dye. The upgrading treatment allowed to obtain carbonaceous materials with quality to be reused as adsorbents or as precursors for activated carbon.

  14. Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials.

    Science.gov (United States)

    Bernardo, M; Mendes, S; Lapa, N; Gonçalves, M; Mendes, B; Pinto, F; Lopes, H

    2014-09-01

    The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing.

  15. Properties of pyrolytic chars and activated carbons derived from pilot-scale pyrolysis of used tires.

    Science.gov (United States)

    Li, S Q; Yao, Q; Wen, S E; Chi, Y; Yan, J H

    2005-09-01

    Used tires were pyrolyzed in a pilot-scale quasi-inert rotary kiln. Influences of variables, such as time, temperature, and agent flow, on the activation of obtained char were subsequently investigated in a laboratory-scale fixed bed. Mesoporous pores are found to be dominant in the pore structures of raw char. Brunauer-Emmett-Teller (BET) surfaces of activated chars increased linearly with carbon burnoff. The carbon burnoff of tire char achieved by carbon dioxide (CO2) under otherwise identical conditions was on average 75% of that achieved by steam, but their BET surfaces are almost the same. The proper activation greatly improved the aqueous adsorption of raw char, especially for small molecular adsorbates, for example, phenol from 6 to 51 mg/g. With increasing burnoff, phenol adsorption exhibited a first-stage linear increase followed by a rapid drop after 30% burnoff. Similarly, iodine adsorption first increased linearly, but it held as the burnoff exceeded 40%, which implied that the reduction of iodine adsorption due to decreasing micropores was partially made up by increasing mesopores. Both raw chars and activated chars showed appreciable adsorption capacity of methylene-blue comparable with that of commercial carbons. Thus, tire-derived activated carbons can be used as an excellent mesoporous adsorbent for larger molecular species.

  16. Effects of Biomass Feedstocks and Gasification Conditions on the Physiochemical Properties of Char

    Directory of Open Access Journals (Sweden)

    Raymond L. Huhnke

    2013-08-01

    Full Text Available Char is a low-value byproduct of biomass gasification and pyrolysis with many potential applications, such as soil amendment and the synthesis of activated carbon and carbon-based catalysts. Considering these high-value applications, char could provide economic benefits to a biorefinery utilizing gasification or pyrolysis technologies. However, the properties of char depend heavily on biomass feedstock, gasifier design and operating conditions. This paper reports the effects of biomass type (switchgrass, sorghum straw and red cedar and equivalence ratio (0.20, 0.25 and 0.28, i.e., the ratio of air supply relative to the air that is required for stoichiometric combustion of biomass, on the physiochemical properties of char derived from gasification. Results show that the Brunauer-Emmett-Teller (BET surface areas of most of the char were 1–10 m2/g and increased as the equivalence ratio increased. Char moisture and fixed carbon contents decreased while ash content increased as equivalence ratio increased. The corresponding Fourier Transform Infrared spectra showed that the surface functional groups of char differed between biomass types but remained similar with change in equivalence ratio.

  17. Combustion and gasification characteristics of chars from raw and torrefied biomass.

    Science.gov (United States)

    Fisher, E M; Dupont, C; Darvell, L I; Commandré, J-M; Saddawi, A; Jones, J M; Grateau, M; Nocquet, T; Salvador, S

    2012-09-01

    Torrefaction is a mild thermal pretreatment (Tbiomass milling and storage properties. The impact of torrefaction on the gasification and oxidation reactivity of chars from torrefied and raw biomass was investigated. Thermogravimetric analysis was used to study the differences in O(2) and steam reactivity, between chars prepared from torrefied and raw willow, under both high- and low-heating-rate conditions. High-heating-rate chars were prepared at 900°C with a residence time of 2s. Low-heating-rate chars were prepared with a heating rate of 33°C/min, a maximum temperature of 850 or 1000°C, and a residence time of 30 min or 1h, respectively, at the maximum temperature. Pretreatment by torrefaction consistently reduced char reactivity. Torrefaction's impact was greatest for high-heating-rate chars, reducing reactivity by a factor of two to three. The effect of torrefaction on a residence time requirements for char burnout and gasification was estimated.

  18. Genetic and phenotypic variation along an ecological gradient in lake trout Salvelinus namaycush

    Science.gov (United States)

    Baillie, Shauna M.; Muir, Andrew M.; Hansen, Michael J.; Krueger, Charles C.; Bentzen, Paul

    2016-01-01

    BackgroundAdaptive radiation involving a colonizing phenotype that rapidly evolves into at least one other ecological variant, or ecotype, has been observed in a variety of freshwater fishes in post-glacial environments. However, few studies consider how phenotypic traits vary with regard to neutral genetic partitioning along ecological gradients. Here, we present the first detailed investigation of lake trout Salvelinus namaycushthat considers variation as a cline rather than discriminatory among ecotypes. Genetic and phenotypic traits organized along common ecological gradients of water depth and geographic distance provide important insights into diversification processes in a lake with high levels of human disturbance from over-fishing.ResultsFour putative lake trout ecotypes could not be distinguished using population genetic methods, despite morphological differences. Neutral genetic partitioning in lake trout was stronger along a gradient of water depth, than by locality or ecotype. Contemporary genetic migration patterns were consistent with isolation-by-depth. Historical gene flow patterns indicated colonization from shallow to deep water. Comparison of phenotypic (Pst) and neutral genetic variation (Fst) revealed that morphological traits related to swimming performance (e.g., buoyancy, pelvic fin length) departed more strongly from neutral expectations along a depth gradient than craniofacial feeding traits. Elevated phenotypic variance with increasing water depth in pelvic fin length indicated possible ongoing character release and diversification. Finally, differences in early growth rate and asymptotic fish length across depth strata may be associated with limiting factors attributable to cold deep-water environments.ConclusionWe provide evidence of reductions in gene flow and divergent natural selection associated with water depth in Lake Superior. Such information is relevant for documenting intraspecific biodiversity in the largest freshwater lake

  19. [Allozyme diversity and genetic divergence of the dolly varden Salvelinus malma Walbaum from the Kuril islands].

    Science.gov (United States)

    Omel'chenko, V T; Salmenkova, E A; Shed'ko, S V

    2002-09-01

    Genetic variation was studied in the southern subspecies of the Asian Dolly Varden Salvelinus malma krascheninnikovi from the Kuril Islands. Thirty-six genetic loci controlling 19 enzyme systems were analyzed in 13 Dolly Varden populations from the Shumshu, Paramushir, Onekotan, Rasshua, Simushir, Urup, Iturup, and Kunashir islands. In the studied populations, the proportion of polymorphic loci was 35 to 85% and the mean heterozygosity was 0.104 to 0.173; populations from the Kunashir Island were characterized by maximum heterozygosity. In the island populations examined, significant inter-population heterogeneity of allele frequencies was found for all studied population pairs. For the total population of all islands, the inter-population diversity (GST = 0.188) was comparable to this parameter for the total population from the Kunashir Island (GST = 0.170). Genetic distances between populations did not correlate with the corresponding geographical distances, which indicates the lack of a pronounced gene exchange between the island populations. Cluster analysis and multidimensional scaling based on genetic distances did not reveal clear groups among the studied populations but indicated greater similarity within the Iturup-Simushir-Urup-Paramushir group and a greater genetic divergence of the Kunashir, Onekotan, Rasshua, and especially Shumshu populations. In the Shumshu population, allele frequencies indicate the admixture of genes of the northern Dolly Varden. The observed pattern of genetic differentiation was probably caused largely by genetic drift under the conditions of a limited gene flow because of homing (which is typical of the Dolly Varden) and the presence of isolated nonanadromous populations. The population-genetic analysis of the Dolly Varden from the Kuril Islands does not give grounds to distinguish any other isolated Dolly Varden species in this region than S. malma, which is represented by the southern form S. m. krascheninnikovi with an

  20. Comparative transcriptomics of anadromous and resident brook charr Salvelinus fontinalis before their first salt water transition

    Directory of Open Access Journals (Sweden)

    Marylène BOULET, Éric NORMANDEAU, Bérénice BOUGAS, Céline AUDET,Louis BERNATCHEZ

    2012-02-01

    Full Text Available Most salmonid taxa have an anadromous life history strategy, whereby fish migrate to saltwater habitats for a growth period before returning to freshwater habitats for spawning. Moreover, several species are characterized by different life history tactics whereby resident and anadromous forms may occur in genetically differentiated populations within a same species, as well as polymorphism within a population. The molecular mechanisms underlying the physiological differences between anadromous and resident forms during the first transition from freshwater to saltwater environments are only partially understood. Insofar research has typically focused on species of the genus Salmo. Here, using a 16,000 cDNA array, we tested the hypothesis that anadromous brook charr Salvelinus fontinalis are characterized by differences in their transcriptome relative to resident brook charr before the anadromous fish migration. Families originating from parapatric populations of anadromous and resident charr were reared in controlled environments mimicking natural temperature and photoperiod, and sampled in spring, while still in fresh water. While anadromous and resident charr showed similar transcriptome profiles in white muscle, they were characterized by striking differences in their gill transcriptome profiles. Genes that were upregulated in the gills of anadromous charr were principally involved in metabolism (mitochondrial electron transport chain, glucose metabolism, and protein synthesis, development (tissue differentiation and innate immunity. We discuss the nature of these transcriptomic differences in relation to molecular mechanisms underlying the expression of anadromous and resident life history tactics and suggest that the anadromous charr express some of the molecular processes present in other migratory salmonids [Current Zoology 58 (1: 158–170, 2012].

  1. Comparative transcriptomics of anadromous and resident brook charr Salvelinus fontinalis before their first salt water transition

    Institute of Scientific and Technical Information of China (English)

    Marylène BOULET; (E)ric NORMANDEAU; Bérénice BOUGAS; Cé1ine AUDET; Louis BERNATCHEZ

    2012-01-01

    Most salmonid taxa have an anadromous life history strategy,whereby fish migrate to saltwater habitats for a growth period before returning to freshwater habitats for spawning.Moreover,several species are characterized by different life history tactics whereby resident and anadromous forms may occur in genetically differentiated populations within a same species,as well as polymorphism within a population.The molecular mechanisms underlying the physiological differences between anadromous and resident forms during the first transition from freshwater to saltwater environments are only partially understood.Insofar research has typically focused on species of the genus Salmo.Here,using a 16,000 cDNA array,we tested the hypothesis that anadromous brook charr Salvelinus fontinalis are characterized by differences in their transcriptome relative to resident brook charr before the anadromous fish migration.Families originating from parapatric populations of anadromous and resident charr were reared in controlled environments mimicking natural temperature and photoperiod,and sampled in spring,while still in fresh water.While anadromous and resident charr showed similar transcriptome profdes in white muscle,they were characterized by striking differences in their gill transcriptome profiles.Genes that were upregulated in the gills of anadromous charr were principally involved in metabolism (mitochondrial electron transport chain,glucose metabolism,and protein synthesis),development (tissue differentiation) and innate immunity.We discuss the nature of these transcriptomic differences in relation to molecular mechanisms underlying the expression of anadromous and resident life history tactics and suggest that the anadromous chart express some of the molecular processes present in other migratory salmonids [Current Zoology 58 (1):158-170,2012].

  2. First report on the bacterial diversity in the distal gut of dholes (Cuon alpinus) by using 16S rRNA gene sequences analysis.

    Science.gov (United States)

    Chen, Lei; Zhang, Honghai; Liu, Guangshuai; Sha, Weilai

    2016-05-01

    The aim of this study was to investigate the bacterial community in the distal gut of dholes (Cuon alpinus) based on the analysis of bacterial 16S rRNA gene sequences. Fecal samples were collected from five healthy unrelated dholes captured from Qilian Mountain in Gansu province of China. The diversity of the fecal bacteria community was investigated by constructing a polymerase chain reaction (PCR)-amplified 16S rRNA gene clone library. Bacterial 16S rRNA gene was amplified by using universal bacterial primers 27F and 1492R. A total of 275 chimera-free near full length 16S rRNA gene sequences were collected, and 78 non-redundant bacteria phylotypes (operational taxonomical units, OTUs) were identified according to the 97 % sequence similarity. Forty-two OTUs (53.8 %) showed less than 98 % sequence similarity to 16S rRNA gene sequences reported previously. Phylogenetic analysis demonstrated that dhole bacterial community comprised five different phyla, with the majority of sequences being classified within the phylum Bacteroidetes (64.7 %), followed by Firmicutes (29.8 %), Fusobacteria (4.7 %),Proteobacteria (0.4 %), and Actinobacteria (0.4 %). The only order Bacteroidales in phylum Bacteroidetes was the most abundant bacterial group in the intestinal bacterial community of dholes. Firmicutes and Bacteroidetes were the two most diverse bacterial phyla with 46.2 and 44.9 % of OTUs contained, respectively. Bacteroidales and Clostridiales were the two most diverse bacterial orders that contained 44.9 and 39.7 % of OTUs, respectively.

  3. A Model-based Phenomenological Investigation of Char Combustion Kinetics through Thermogravimetry

    Institute of Scientific and Technical Information of China (English)

    Qun CHEN; Rong HE; Zhan Gang LIANG; Xu Chang XU; Chang He CHEN

    2005-01-01

    Five coal char samples were burnt in thermobalance with ramp heating rate of 30 K/min.The pore structure of these char samples was studied through mercury intrusion method.Combined with the kinetic theory of gases, the data of surface area was used in fitting the results.As a result, the kinetic triplet was given. The analysis showed that five char samples share almost the same intrinsic activation energy of the overall reaction. The phenomenological implication of the derived combustion rate equation was given.

  4. Investigation of wetting behavior of coal-chars with liquid iron by sessile drop method.

    OpenAIRE

    Veena Sahajwalla; Fiona McCarthy; Rita Khanna

    2008-01-01

    Using the sessile drop approach, the wettability of four non-graphitic coal-chars with electrolytic iron and Fe-2 % C-0.01 % S alloy has been determined at 1550°C, in a horizontal tube resistance furnace with an argon atmosphere. The ash concentration in chars ranged between 9.04 to 12.61 wt %, with alumina and silica as predominant ash components. The contact angles of these chars with liquid Fe-2 % C-0.01 % S alloy showed lesser variations with time as compared to corresponding angles with ...

  5. Comparison of the carbon-sequestering abilities of pineapple leaf residue chars produced by controlled combustion and by field burning.

    Science.gov (United States)

    Leng, L Y; Husni, M H A; Samsuri, A W

    2011-11-01

    This study was undertaken to compare the chemical properties and yields of pineapple leaf residue (PLR) char produced by field burning (CF) with that produced by a partial combustion of air-dried PLR at 340 °C for 3 h in a furnace (CL). Higher total C, lignin content, and yield from CL as well as the presence of aromatic compounds in the Fourier Transform Infrared spectra of the char produced from CL suggest that the CL process was better in sequestering C than was the CF process. Although the C/N ratio of char produced from CL was low indicating a high N content of the char, the C in the char produced from CL was dominated by lignin suggesting that the decomposition of char produced from CL would be slow. To sequester C by char application, the PLR should be combusted in a controlled process rather than by burning in the field.

  6. Coal devolatilization and char conversion under suspension fired conditions in O2/N2 and O2/CO2 atmospheres

    DEFF Research Database (Denmark)

    Jensen, Anker Degn; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    was burned at 1573 K and 1673 K a faster conversion was found in N2 suggesting that the lower molecular diffusion coefficient of O2 in CO2 lowers the char conversion rate when external mass transfer influences combustion. The reaction of char with CO2 was not observed to have an influence on char conversion......The aim of the present investigation is to examine differences between O2/N2 and O2/CO2 atmospheres during devolatilization and char conversion of a bituminous coal at conditions covering temperatures between 1173 K and 1673 K and inlet oxygen concentrations between 5 and 28 vol.%. The experiments...... indicates that a shift from air to oxy-fuel combustion does not influence the devolatilization process significantly. Char combustion experiments yielded similar char conversion profiles when N2 was replaced with CO2 under conditions where combustion was primarily controlled by chemical kinetics. When char...

  7. Effect of burn-off on physical and chemical properties of coal char; Gas ka shinko ni tomonau sekitan char no tokusei henka

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, T.; Tamura, K.; Hashimoto, H.; Funaki, M.; Suzuki, T. [Kitami Institute of Technology, Hokkaido (Japan)

    1996-10-28

    For high-efficiency coal gasification, investigations were given on effect of coal chars with different conversion rates on coal gasification reactivity. In coal gasification, reactivity of char after pyrolysis governs the efficiency. The reference char conversion in CO2 gasification of coal (weight loss) changes linearly in the initial stage of the reaction, but the reactivity declines as the end point is approached. Char surface area is as large as 400 m{sup 2}/g in the initial stage with the conversion at 20%, but it decreases in the final stage. This phenomenon relates closely with changes in pore size and crystalline structure. Change in the Raman value R which shows incompleteness of char graphite structure and amorphous carbon ratio suggests that an active portion with high reactivity is oxidized preferentially, and a portion with low reactivity remains finally. Minerals in coal are known to accelerate the gasification. However, their catalytic effect is related with chemical forms, and complex as they may change into inactive sulfides and silicates under severe reaction conditions. Change in forms of calcium compounds may also be involved in decline of the reactivity in the latter stage. 8 refs., 4 figs.

  8. Sorption of diuron, atrazine, and copper ion on chars with long-term natural oxidation in soils

    Science.gov (United States)

    Cheng, C.; Lin, T.; Lai, C.

    2011-12-01

    Biochar has been proposed as a measure to sequestrate carbon (C) and to increase soil fertility in sustainable agriculture. However, its sorption characteristics to herbicides, such as lowing herbicides efficacy, may constrain its agricultural application. This assertion may be arguable because most studies so far were conducted with the newly produced char and barely considered the "ageing effect" of old char since it could be oxidized over long time. In this study, historical char samples were collected and compared with the newly produced char. Batch sorption studies of diuron, atrazine, and copper ion onto chars was performed. Greater sorption of Cu was observed on the historical char samples and reached a saturated sorption at 30 mg g-1 for Cu, much higher adsorption value than newly produced char at 4 mg g-1. In contrast, sorption of diuron and atrazine on newly produced char had the highest sorption capacity than the historical char samples. The historical chars also had much higher negative charge than the newly produced char, but its surface area were lower than the new char. The results indicated that change in surface functional groups through natural oxidation rather than the change of surface area may have more pronounced influences on sorption characteristics, in which the negative charge on the historical chars' surface could hinder the adsorption of diuron and atrazine while enhance the sorption to copper ion. Biological assay to test the toxicity of diuron and copper ion for both historical and new chars on rye seed were conducted and will be presented in our poster.

  9. Evaluating the growth potential of sea lampreys (Petromyzon marinus) feeding on siscowet lake trout (Salvelinus namaycush) in Lake Superior

    Science.gov (United States)

    Moody, E.K.; Weidel, B.C.; Ahrenstorff, T.D.; Mattes, W.P.; Kitchell, J.F.

    2011-01-01

    Differences in the preferred thermal habitat of Lake Superior lake trout morphotypes create alternative growth scenarios for parasitic sea lamprey (Petromyzon marinus) attached to lake trout hosts. Siscowet lake trout (Salvelinus namaycush) inhabit deep, consistently cold water (4–6 °C) and are more abundant than lean lake trout (Salvelinus namaycush) which occupy temperatures between 8 and 12 °C during summer thermal stratification. Using bioenergetics models we contrasted the growth potential of sea lampreys attached to siscowet and lean lake trout to determine how host temperature influences the growth and ultimate size of adult sea lamprey. Sea lampreys simulated under the thermal regime of siscowets are capable of reaching sizes within the range of adult sea lamprey sizes observed in Lake Superior tributaries. High lamprey wounding rates on siscowets suggest siscowets are important lamprey hosts. In addition, siscowets have higher survival rates from lamprey attacks than those observed for lean lake trout which raises the prospect that siscowets serve as a buffer to predation on more commercially desirable hosts such as lean lake trout, and could serve to subsidize lamprey growth.

  10. Physical and thermochemical characterization of rice husk char as a potential biomass energy source.

    Science.gov (United States)

    Maiti, S; Dey, S; Purakayastha, S; Ghosh, B

    2006-11-01

    The fixed bed pyrolysis of rice husk was studied under conventional conditions with the aim of determining the characteristics of the charcoal formed for its applicability as a solid fuel. Thermoanalytic methods were used to determine the kinetic parameters of its combustion. Palletisation using different binders and techniques to improve the time of sustained combustion of the char pallets were investigated. The optimum temperature for carbonization to obtain a char having moderately high heating value was found as 400 degrees C. For the active char combustion zone, the order of reaction was nearly 1, the activation energy 73.403 kJ/mol and the pre-exponential factor 4.97 x 10(4)min(-1). Addition of starch as a binder and 10% ferrous sulphate heptahydrate or sodium hypophosphite as an additive enhanced the ignitibility of the char pallets.

  11. The different effects of applying fresh, composted or charred manure on soil N2O emissions

    DEFF Research Database (Denmark)

    Zhu, Kun; Christel, Wibke; Bruun, Sander;

    2014-01-01

    New manure management strategies and technologies are currently being developed in order to reduce manure volume and odorous emissions, utilise energy potential and produce improved manure-derived fertilisers. This has accentuated the need to determine their effects on greenhouse gas emissions...... to higher N2O and CO2 emissions than heterogeneous distribution. However, the effect of different distribution modes was not significant in treatments with charred manure, since N turnover in the immature compost was much more active than that in the charred manure. By combining charred manure...... with composted manure, N2O emissions were significantly reduced by 41% at pF 2.0, but the mitigation effect of charred manure was not observed at lower soil water potentials. © 2014 Elsevier Ltd....

  12. Modeling and Countermeasures of Combustion Characteristics of Char Particles in CFBC

    Institute of Scientific and Technical Information of China (English)

    YanJin; QiayuZheng; 等

    1999-01-01

    A mathematical model of single char particle combustion in circulating fluidized bed combustor(CFBC) is developed in this paper in this paper,its numerical solution in operating conditions of CFBC verifies the nature of a phenomenon that the distribution of carbon content of char particles has a peak value versus their diameters.The results show that the temperature of smaller char particle is close to the bed temperature,and there also exits a peak value for the burn-out time of char particles versus their diameters.The countermeasures are presented to improve combustion of fine particles,such as use of the fly-ash recirculation,the hot cyclone,and so on.

  13. Influence of Pyrolysis Temperature on Rice Husk Char Characteristics and Its Tar Adsorption Capability

    Directory of Open Access Journals (Sweden)

    Anchan Paethanom

    2012-11-01

    Full Text Available A biomass waste, rice husk, was inspected by thermoanalytical investigation to evaluate its capability as an adsorbent medium for tar removal. The pyrolysis process has been applied to the rice husk material at different temperatures 600, 800 and 1000 °C with 20 °C/min heating rate, to investigate two topics: (1 influence of temperature on characterization of rice husk char and; (2 adsorption capability of rice husk char for tar removal. The results showed that subsequent to high temperature pyrolysis, rice husk char became a highly porous material, which was suitable as tar removal adsorbent with the ability to remove tar effectively. In addition, char characteristics and tar removal ability were significantly influenced by the pyrolysis temperature.

  14. Prediction of the burnout behaviour of chars derived from coal-biomass blends

    Energy Technology Data Exchange (ETDEWEB)

    Tao Wu; Mei Gong; Edward Lester [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering

    2007-07-01

    Nowadays, biomass has been considered an alternative fuel to coal and is being used in power plants to replace part of coal used. This study is to investigate the potential of burning biomass with coal and its impacts on burnout levels. Daw Mill coal was selected for burnout modelling together with three biomasses, Cereal, PKE and Olive Cake. Chars were prepared (75-106 micron) and characterised using image analysis methods as in input data into the char burnout model (ChB) which was adapted to allow the prediction of char burnout of biomass-coal blends under typical pf combustion conditions. The burnout performance of four blend compositions for each biomass were modelled (5%, 10%, 20% and 30%). In practice, the low heating-value of biomass produces a lower flame temperature which can lead to lower levels of char burn-out. The effect is closely linked with the type of biomass used. 36 refs., 4 figs., 1 tab.

  15. Behaviors of Char Gasification Based on Two-stage Gasifier of Biomass

    Science.gov (United States)

    Taniguchi, Miki; Sasauchi, Kenichi; Ahn, Chulju; Ito, Yusuke; Hayashi, Toshiaki; Akamatsu, Fumiteru

    In order to develop a small-scale gasifier in which biomass can be converted to energy with high efficiency, we planed a gasification process that consists of two parts: pyrolysis part (rotary kiln) and gasification part (downdraft gasifier). We performed fundamental experiments on gasification part and discussed the apropriate conditions such as air supply location, air ratio, air temperature and hearth load. The following results was found: 1) the air supply into the char bed is more effective than that into the gas phase, 2) we can have the maximum cold gas efficiency of 80% on the following conditions: air supply location: char layer, air temperature: 20°C, air ratio: 0.2. 3) As air temperature is higher, the cold gas efficiency is larger. As for the hearth load, the cold gas efficiency becomes higher and reaches the constant level. It is expected from the results that high temperature in the char layer is effective on the char gasification.

  16. STRUCTURE-BASED PREDICTIVE MODEL FOR COAL CHAR COMBUSTION

    Energy Technology Data Exchange (ETDEWEB)

    CHRISTOPHER M. HADAD; JOSEPH M. CALO; ROBERT H. ESSENHIGH; ROBERT H. HURT

    1998-06-04

    During the past quarter of this project, significant progress continued was made on both major technical tasks. Progress was made at OSU on advancing the application of computational chemistry to oxidative attack on model polyaromatic hydrocarbons (PAHs) and graphitic structures. This work is directed at the application of quantitative ab initio molecular orbital theory to address the decomposition products and mechanisms of coal char reactivity. Previously, it was shown that the �hybrid� B3LYP method can be used to provide quantitative information concerning the stability of the corresponding radicals that arise by hydrogen atom abstraction from monocyclic aromatic rings. In the most recent quarter, these approaches have been extended to larger carbocyclic ring systems, such as coronene, in order to compare the properties of a large carbonaceous PAH to that of the smaller, monocyclic aromatic systems. It was concluded that, at least for bond dissociation energy considerations, the properties of the large PAHs can be modeled reasonably well by smaller systems. In addition to the preceding work, investigations were initiated on the interaction of selected radicals in the �radical pool� with the different types of aromatic structures. In particular, the different pathways for addition vs. abstraction to benzene and furan by H and OH radicals were examined. Thus far, the addition channel appears to be significantly favored over abstraction on both kinetic and thermochemical grounds. Experimental work at Brown University in support of the development of predictive structural models of coal char combustion was focused on elucidating the role of coal mineral matter impurities on reactivity. An �inverse� approach was used where a carbon material was doped with coal mineral matter. The carbon material was derived from a high carbon content fly ash (Fly Ash 23 from the Salem Basin Power Plant. The ash was obtained from Pittsburgh #8 coal (PSOC 1451). Doped

  17. Development of a multichemical food web model: application to PBDEs in Lake Ellasjoen, Bear Island, Norway.

    Science.gov (United States)

    Gandhi, Nilima; Bhavsar, Satyendra P; Gewurtz, Sarah B; Diamond, Miriam L; Evenset, Anita; Christensen, Guttorm N; Gregor, Dennis

    2006-08-01

    A multichemical food web model has been developed to estimate the biomagnification of interconverting chemicals in aquatic food webs. We extended a fugacity-based food web model for single chemicals to account for reversible and irreversible biotransformation among a parent chemical and transformation products, by simultaneously solving mass balance equations of the chemicals using a matrix solution. The model can be applied to any number of chemicals and organisms or taxonomic groups in a food web. The model was illustratively applied to four PBDE congeners, BDE-47, -99, -100, and -153, in the food web of Lake Ellasjøen, Bear Island, Norway. In Ellasjøen arctic char (Salvelinus alpinus), the multichemical model estimated PBDE biotransformation from higher to lower brominated congeners and improved the correspondence between estimated and measured concentrations in comparison to estimates from the single-chemical food web model. The underestimation of BDE-47, even after considering bioformation due to biotransformation of the otherthree congeners, suggests its formation from additional biotransformation pathways not considered in this application. The model estimates approximate values for congener-specific biotransformation half-lives of 5.7,0.8,1.14, and 0.45 years for BDE-47, -99, -100, and -153, respectively, in large arctic char (S. alpinus) of Lake Ellasjøen.

  18. Development of coconut pith chars towards high elemental mercury adsorption performance - Effect of pyrolysis temperatures.

    Science.gov (United States)

    Johari, Khairiraihanna; Saman, Norasikin; Song, Shiow Tien; Cheu, Siew Chin; Kong, Helen; Mat, Hanapi

    2016-08-01

    In this study, chars from coconut pith (CP) were prepared aiming for superior adsorption towards elemental mercury (Hg(o)). The yield, proximate analysis, textural characteristics, surface functional groups and elemental composition analyses of the chars produced at pyrolysis temperature of 300 °C, 500 °C, 700 °C and 900 °C were compared. The surface area, pore volume, ash and carbon content of chars increased, while the yield and moisture content decreased with increasing pyrolysis temperatures. The changing of physical and chemical properties of the chars produced at variety pyrolysis temperature was much effect on the Hg(o) adsorption performance and definitely provides important information on the Hg(o) adsorption mechanism. The highest Hg(o) adsorption capacity was observed for CP900 (6067.49 μg/g), followed by CP700 (2395.98 μg/g), CP500 (289.76 μg/g), CP300 (1.68 μg/g), and CP (0.73 μg/g). The equilibrium data were well described by the Freundlich adsorption isotherm model. The pseudo-second order best described the kinetic data of the Hg(o) adsorption onto CP and CP300. For chars produced at higher pyrolysis temperature, however, the pseudo-zero order and pseudo-second order fitted well for the adsorption and breakthrough regions, respectively. The Hg(o) adsorption capacity of chars obtained from high pyrolysis temperature of CP significantly outperformed the commercial activated carbon (Darco KB-B) as well as superior to chars reported in the literature indicating the CP can be used as a precursor for preparation of chars as elemental mercury adsorbents.

  19. Characterization, leachability and valorization through combustion of residual chars from gasification of coals with pine.

    Science.gov (United States)

    Galhetas, Margarida; Lopes, Helena; Freire, Márcia; Abelha, Pedro; Pinto, Filomena; Gulyurtlu, Ibrahim

    2012-04-01

    This paper presents the study of the combustion of char residues produced during co-gasification of coal with pine with the aim of characterizing them for their potential use for energy. These residues are generally rich in carbon with the presence of other elements, with particular concern for heavy metals and pollutant precursors, depending on the original fuel used. The evaluation of environmental toxicity of the char residues was performed through application of different leaching tests (EN12457-2, US EPA-1311 TCLP and EA NEN 7371:2004). The results showed that the residues present quite low toxicity for some of pollutants. However, depending on the fuel used, possible presence of other pollutants may bring environmental risks. The utilization of these char residues for energy was in this study evaluated, by burning them as a first step pre-treatment prior to landfilling. The thermo-gravimetric analysis and ash fusibility studies revealed an adequate thermochemical behavior, without presenting any major operational risks. Fluidized bed combustion was applied to char residues. Above 700°C, very high carbon conversion ratios were obtained and it seemed that the thermal oxidation of char residues was easier than that of the coals. It was found that the char tendency for releasing SO(2) during its oxidation was lower than for the parent coal, while for NO(X) emissions, the trend was observed to increase NO(X) formation. However, for both pollutants the same control techniques might be applied during char combustion, as for coal. Furthermore, the leachability of ashes resulting from the combustion of char residues appeared to be lower than those produced from direct coal combustion.

  20. Influence of post-treatment strategies on the properties of activated chars from broiler manure.

    Science.gov (United States)

    Lima, Isabel M; Boykin, Debbie L; Thomas Klasson, K; Uchimiya, Minori

    2014-01-01

    There are a myriad of carbonaceous precursors that can be used advantageously to produce activated carbons or chars, due to their low cost, availability and intrinsic properties. Because of the nature of the raw material, production of granular activated chars from broiler manure results in a significant ash fraction. This study was conducted to determine the influence of several pre- and post-treatment strategies in various physicochemical and adsorptive properties of the resulting activated chars. Pelletized samples of broiler litter and cake were pyrolyzed at 700 °C for 1h followed by a 45 min steam activation at 800 °C at different water flow rates from 1 to 5 mL min(-1). For each activation strategy, samples were either water-rinsed or acid-washed and rinsed or used as is (no acid wash/rinse). Activated char's physicochemical and adsorptive properties towards copper ions were selectively affected by both pre- and post-treatments. Percent ash reduction after either rinsing or acid washing ranged from 1.1 to 15.1% but washed activated chars were still alkaline with pH ranging from 8.4 to 9.1. Acid washing or water rinsing had no significant effect in the ability of the activated char to adsorb copper ions, however it significantly affected surface area, pH, ash content and carbon content. Instead, manure type (litter versus cake) and the activation water flow rate were determining factors in copper ion adsorption which ranged from 38 mg g(-1) to 104 mg g(-1) of activated char. Moreover, strong positive correlations were found between copper uptake and concentration of certain elements in the activated char such as phosphorous, sulfur, calcium and sodium. Rinsing could suffice as a post treatment strategy for ash reduction since no significant differences in the carbon properties were observed between rinsed and acid wash treatments.

  1. Experimental Study and Modelling of Char Combustion under Fluidized Bed Conditions

    Institute of Scientific and Technical Information of China (English)

    ZhangYongzhe; ManfredC.Wirsum; 等

    1998-01-01

    The combustion behavior of chars from two Chinese coals has been investigated in a laboratory scale bubbling fludized bed system in Siegen University,Germany,Experimental equipment and method are introduced.The shrinking-core model and the “shrinking-particl” model were employed to evaluate the kinetic parameters.The results indicated that the char conversion process of these two coals can be well described by the two models.

  2. Mixed waste treatment using the ChemChar thermolytic detoxification technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuchynka, D. [Mirage Systems, Sunnyvale, CA (United States)

    1995-10-01

    The diversity of mixed waste matrices contained at Department of Energy sites that require treatment preclude a single, universal treatment technology capable of handling sludges, solids, heterogeneous debris, aqueous and organic liquids and soils. This report describes the ChemChar thermolytic detoxification process. The process is a thermal, chemically reductive technology that converts the organic portion of mixed wastes to a synthesis gas, while simultaneously absorbing volatile inorganics on a carbon-based char.

  3. ENHANCING ASPHALT RHEOLOGICAL BEHAVIOR AND AGING SUSCEPTIBILITY USING BIO-CHAR AND NANO-CLAY

    Directory of Open Access Journals (Sweden)

    Renaldo C. Walters

    2014-01-01

    Full Text Available The life expectancy of Asphalt Binder (AB has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster, which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact of bio-char and nano-clay of asphalt rheological properties. Two nano scale materials were used for this study were nano-clay and bio-char. Nano-clay (Cloisite 30B is a naturally occurring inorganic mineral. Bio-char is the waste product from bio-binder production. Bio-binder is produced from swine manure using a thermochemical conversion process. This process is then followed by a filtration procedure where the bio-char is produced. Chemical and physical properties of bio-char showed a significant presence of carbon which could in turn enhance asphalt flow properties and reduce the rate of asphalt oxidation. In this study several mixtures are designed and evaluated using Rotational Viscometer testing (RV and X-Ray Diffraction (XRD. Nano-clay is blended at 2 and 4% by weight, with and without bio-binder (5% by weight of dry mass. Bio-char is grinded to nano scale and added to the virgin asphalt binder (PG 64-22 at 2, 5 and 10% by weight. The study results showed that introduction of nano-clay could be effective in reducing temperature susceptibility of asphalt binder.

  4. Improvement of biomass char-CO{sub 2} gasification reactivity using microwave irradiation and natural catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lahijani, Pooya, E-mail: pooya.lahijani@gmail.com [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohammadi, Maedeh, E-mail: m.mohammadi@nit.ac.ir [Faculty of Chemical Engineering, Babol Noushirvani University of Technology, 47148 Babol (Iran, Islamic Republic of); Zainal, Zainal Alimuddin, E-mail: mezainal@eng.usm.my [Biomass and Bioenergy Laboratory, School of Mechanical Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Mohamed, Abdul Rahman, E-mail: chrahman@usm.my [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-03-20

    Highlights: • We study microwave-induced gasification of EFB ash-loaded biomass char with CO{sub 2}. • Synergistic effect of microwave and catalyst resulted in CO{sub 2} conversion of 93%. • Gasification of pristine char using conventional heating gives CO{sub 2} conversion of 58%. • E{sub a} of 74 and 247 kJ/mol were obtained for microwave and conventional CO{sub 2} gasification. - Abstract: In char-CO{sub 2} gasification, the highly endothermic nature of the Boudouard reaction (CO{sub 2} (g) + C (s) ↔ 2CO (g)) dictates use of very high temperatures to shift the equilibrium towards CO production. In this study, such high temperature (750–900 °C) was provided by microwave irradiation. A microwave heating system was developed to perform the gasification tests by passing CO{sub 2} through a packed bed of oil palm shell (OPS) char. In order to speed up the microwave-induced CO{sub 2} gasification, ash of palm empty fruit bunch (EFB) was used as natural catalyst (rich in potassium) and incorporated into the skeleton of the OPS char. The synergistic effect of microwave and catalyst concluded to very encouraging results, where a CO{sub 2} conversion of 93% was achieved at 900 °C, within 60 min microwave gasification. In comparison, CO{sub 2} conversion in thermal gasification (conventional heating) of pristine OPS char was only 58% under the same operating condition.

  5. Investigation of wetting behavior of coal-chars with liquid iron by sessile drop method.

    Directory of Open Access Journals (Sweden)

    Veena Sahajwalla

    2008-06-01

    Full Text Available Using the sessile drop approach, the wettability of four non-graphitic coal-chars with electrolytic iron and Fe-2 % C-0.01 % S alloy has been determined at 1550°C, in a horizontal tube resistance furnace with an argon atmosphere. The ash concentration in chars ranged between 9.04 to 12.61 wt %, with alumina and silica as predominant ash components. The contact angles of these chars with liquid Fe-2 % C-0.01 % S alloy showed lesser variations with time as compared to corresponding angles with electrolytic iron. While the initial contact angles ranged between 106° and 137°, the contact angles for all coal-chars were quite similar after 60 minutes of contact (105 - 110°. While no well defined correlations could be observed between the initial char structure (Lc values and ash concentration / composition and contact angles in the initial stages of contact, the contact angles over extended periods were significantly affected by the presence of reaction products and impurity deposits in the interfacial region. With coal-chars generally showing a non-wetting behavior with liquid iron, these results are discussed in terms of the transfer of carbon and sulphur by mass transport across the interface, the formation of an enriched interfacial layer containing calcium, sulphur and alumina, reduction of reducible oxides such as silica and iron oxides, and possible transfer of these elements into the liquid iron.

  6. Properties of slurries made of fast pyrolysis oil and char or beech wood

    DEFF Research Database (Denmark)

    Trinh, Ngoc Trung; Jensen, Peter Arendt; Dam-Johansen, Kim

    2014-01-01

    The properties of slurries made of pyrolysis oil mixed with wood, char or ground char were investigated with respect to phase transitions, rheological properties, elemental compositions, and energy density. Also the pumping properties of the slurries were investigated at temperatures of 25, 40...... and 60 C and solid loadings from 0 to 20 wt%. The phase transitions of the wood slurry samples were observed at lower solid loadings compared to the char slurry samples. The apparent viscosity of the slurry samples was found to be considerably impacted by solid loading (0e20 wt%) and temperature (25e60 C......), especially in the phase transition region. The slurry viscosities with 20 wt% char loading, 20 wt% ground char loading and 15 wt% wood loading (at a shear rate of 100 s1) are 0.7, 1.0 and 1.7 Pa.s, respectively at 60 C and these values increases 1.2e1.4 times at 40 C and 3e4 times at 25 C. The wood, char...

  7. The potential applications of using compost chars for removing the hydrophobic herbicide atrazine from solution

    Science.gov (United States)

    Tsui, L.; Roy, W.R.

    2008-01-01

    One commercial compost sample was pyrolyzed to produce chars as a sorbent for removing the herbicide atrazine from solution. The sorption behavior of compost-based char was compared with that of an activated carbon derived from corn stillage. When compost was pyrolyzed, the char yield was greater than 45% when heated under air, and 52% when heated under N2. In contrast, when the corn stillage was pyrolyzed under N2, the yield was only 22%. The N2-BET surface area of corn stillage activated carbon was 439 m2/g, which was much greater than the maximum compost char surface area of 72 m2/g. However, the sorption affinity of the compost char for dissolved atrazine was comparable to that of the corn stillage activated carbon. This similarity could have resulted from the initial organic waste being subjected to a relatively long period of thermal processes during composting, and thus, the compost was more thermally stable when compared with the raw materials. In addition, microorganisms transformed the organic wastes into amorphous humic substances, and thus, it was likely that the microporisity was enhanced. Although this micropore structure could not be detected by the N2-BET method, it was apparent in the atrazine sorption experiment. Overall, the experimental results suggested that the compost sample in current study was a relatively stable material thermally for producing char, and that it has the potential as a feed stock for making high-quality activated carbon. ?? 2007 Elsevier Ltd. All rights reserved.

  8. Effects of Charred Fructus Crataegi on the contractilily of isolated rat gastric and intestine muscle strips

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hou-li; DIAO Yun-peng; LIU Zhi-hao; HUANG Shan-shan; MA Xiao-chi; LIN Yuan

    2008-01-01

    Objective The purpose of the study is to investigate the effects of Charred Fructus Crataegi Alcohol Extract on contractililty of isolated rat gastric and intesting smooth muscle strips. Methods Isolated rat intestine was selected in the assay to test the effects of Charred Fructus Crataegi Alcohol Extract on contractilty of isolated rat gastric and intestine smooth muscle strips using Krebs' solution, to observe the effects of in the presence of acetylcholine or atropine. Results Charred Fructus Crataegi Alcohol Extract in the range of 2-8 rag crude drugs/mL could significantly reduce the contractility of rat gastric and intestine smooth muscle strips in a dose-dependent manner, and Charred Fructus Crataegi Alcohol Extract 8 mg·mL-1(crude drugs) could inhibit the stimulation induced by acetylcholine. Charred Fructus Crataegi Alcohol Extract 8 mg·mL-1(crude drugs) was found to have a inhibiton of the relaxtion concurrently used with atropin. Conclusions The results suggest that Charred Fructus Crataegi Alcohol Extract has prominent inhibitory effects on the contractile activity of isolated rat gastric and intestine smooth muscle strips.

  9. Co-gasification of tire and biomass for enhancement of tire-char reactivity in CO2 gasification process.

    Science.gov (United States)

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2013-06-01

    In this investigation, palm empty fruit bunch (EFB) and almond shell (AS) were implemented as two natural catalysts rich in alkali metals, especially potassium, to enhance the reactivity of tire-char through co-gasification process. Co-gasification experiments were conducted at several blending ratios using isothermal Thermogravimetric analysis (TGA) under CO2. The pronounced effect of inherent alkali content of biomass-chars on promoting the reactivity of tire-char was proven when acid-treated biomass-chars did not exert any catalytic effect on improving the reactivity of tire-char in co-gasification experiments. In kinetic studies of the co-gasified samples in chemically-controlled regime, modified random pore model (M-RPM) was adopted to describe the reactive behavior of the tire-char/biomass-char blends. By virtue of the catalytic effect of biomass, the activation energy for tire-char gasification was lowered from 250 kJ/mol in pure form 203 to 187 kJ/mol for AS-char and EFB-char co-gasified samples, respectively.

  10. Reactivity and characterisation of various rank Turkish bituminous coal chars

    Energy Technology Data Exchange (ETDEWEB)

    Kizgut, S.; Baran, Y.; Cuhadaroglu, D. [Karaelmas University, Zonguldak (Turkey). Faculty of Engineering

    2003-07-01

    A set of seven bituminous coal chars has been characterised by IR spectroscopy (FTIR), thermogravimetry (TG) and elemental analysis. FTIR study provided suitable information to establish differences between coal samples according to their chemical compositions. The reactivity of these samples was also studied and correlated with the coal parameters of mean vitrinite reflectance, fuel ratio and H/C ratio. The data suggest that reactivity as determined can be correlated with the mean vitrinite reflectance, fuel ratio and H/C ratio (0.90). The order of reactivity of samples were; Amasra (S1) (R-m=0.65) > Azdavay (S4) (R-m=0.99) {approx_equal} Armutcuk (S2) (R-m=0.81) {approx_equal} Acenta (S3) (R-m=0.92) > Ac2l2k (S6) (R-m=1.11) Cay (S5) (R-m=1.03) > Sogutozu (S7) (R-m=2.14).

  11. Study on denitration technology of coal char reduction method

    Directory of Open Access Journals (Sweden)

    Wenjie FU

    2016-06-01

    Full Text Available In order to more effectively control NO emissions in coal-fired flue gas, the denitration reaction is carried out with simulated industrial boiler flue gas in a fixed bed reactor. The influence of char types, reaction conditions, the composition of flue gas and other factors on the conversion rate of NO are discussed. The result shows that the industrial semi-coke is the most suitable experimental coal in the three coals studied, and the industrial semi-coke particle size of 0.6 ~ 10 mm is relatively suitable; The conversion rate of NO increases gradually with the increase of temperature, and when the reaction temperature is 700 ℃ and the space velocity is 10 000 h-1, the conversion rate of NO can reach 99%; the conversion rate of NO decreases gradually as airspeed increases, but the airspeed change has no effect on the conversion rate of NO at 700 ℃; under anaerobic conditions,the change of NO concentration has no effect on the conversion rate of NO; at the same temperature, NO conversion rate is higher at the presence of oxygen compared with that at anaerobic situation, and the conversion rate of NO is the highest when O2 concentration is 4%; under aerobic conditions, the concentration change of SO2 and CO2 has no effect on the conversion rate of NO.

  12. Efficacy of Locust Beans Husk Char in Heavy Metal Sequestration

    Directory of Open Access Journals (Sweden)

    Ademola Ayodeji Ajayi-Banji

    2016-03-01

    Full Text Available Most solid waste management schemes minimally consider low concentration biodegradable agricultural waste management, though the environmental impact of this waste category is significant over a time frame. The column-mode study seeks to address the issue by suggesting potential utilisation of post-harvest waste for heavy metal sequestering. Locust beans husk char of 100 and 200 g was employed to inspect removal efficiency, isotherm and kinetic models of some heavy metals at 30, 60, 90, 120 and 150 min contact time. Elemental composition of the biosorbent was investigated using the SEM-EDX machine. The results obtained depict that over 85% aluminium and nickel removal was achieved at 150 min detention time. The Freundlich isotherm well described most of the sorbates sorption (R2 ≥ 0.91. The sorption rate equally fitted into the second-order pseudo kinetic model (R2 ≥ 0.88. Ion exchange took place during the sorption. Locust beans husk has promising adsorption potential in heavy metal ions removal from fouled surface water. DOI: http://dx.doi.org/10.5755/j01.erem.71.4.13081

  13. Investigation of growth responses in saprophytic fungi to charred biomass.

    Science.gov (United States)

    Ascough, Philippa L; Sturrock, Craig J; Bird, Michael I

    2010-03-01

    We present the results of a study testing the response of two saprophytic white-rot fungi species, Pleurotus pulmonarius and Coriolus versicolor, to charred biomass (charcoal) as a growth substrate. We used a combination of optical microscopy, scanning electron microscopy, elemental abundance measurements, and isotope ratio mass spectrometry ((13)C and (15)N) to investigate fungal colonisation of control and incubated samples of Scots Pine (Pinus sylvestris) wood, and charcoal from the same species produced at 300 degrees C and 400 degrees C. Both species of fungi colonise the surface and interior of wood and charcoals over time periods of less than 70 days; however, distinctly different growth forms are evident between the exterior and interior of the charcoal substrate, with hyphal penetration concentrated along lines of structural weakness. Although the fungi were able to degrade and metabolise the pine wood, charcoal does not form a readily available source of fungal nutrients at least for these species under the conditions used in this study.

  14. Conversion of char nitrogen to N2 under incomplete combustion conditions; Fukanzen nensho jokenka ni okeru char chuchisso no N2 eno tenka

    Energy Technology Data Exchange (ETDEWEB)

    Zhuang, Q.; Yamauchi, A.; Oshima, Y.; Wu, Z.; Otsuka, Y. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

    1996-10-28

    The effect of combustion conditions on conversion of char nitrogen to N2 was studied in the combustion experiment of char obtained by pyrolysis of coal. Char specimen was prepared by holding ZN coal of Chinese lignite in Ar atmosphere at 1123K for one hour. A batch scale quartz-made fluidized bed reactor was used for combustion experiment. After the specimen was fluidized in reaction gas, it was rapidly heated to start combustion reaction. CO, CO2 and N2 in produced gases were online measured by gas chromatography (GC). As the experimental result, under the incomplete combustion condition where a large amount of CO was produced by consuming almost all of O2, no NOx and N2O produced from char were found, and almost all of N-containing gas was N2. At the final stage of combustion, pyridinic-N disappeared completely, and pyrrolic-N decreased, while O-containing nitrogen complexes became a main component. It was thus suggested that O-containing nitrogen complexes are playing the role of intermediate product in combustion reaction. 7 refs., 4 figs., 1 tab.

  15. The effect of 150μm expandable graphite on char expansion of intumescent fire retardant coating

    Energy Technology Data Exchange (ETDEWEB)

    Ullah, Sami, E-mail: samichemist1@gmail.com; Shariff, A. M., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my; Bustam, M. A., E-mail: azmish@petronas.com.my, E-mail: azmibustam@petronas.com.my [Research Center for Carbon Dioxide Capture, Department of Chemical Engineering, Universiti Techologi PETRONAS, Bandar Sri Iskandar, Tronoh 31750 Perak (Malaysia); Ahmad, Faiz, E-mail: faizahmadster@gmail.com [Department of Mechanical Engineering, Universiti Techologi PETRONAS, Bandar Sri Iskandar, Tronoh 31750 Perak (Malaysia)

    2014-10-24

    Intumescent is defined as the swelling of certain substances to insulate the underlying substrate when they are heated. In this research work the effect of 150μm expandable graphite (EG) was studied on char expansion, char morphology and char composition of intumescent coating formulations (ICFs). To study the expansion and thermal properties of the coating, nine different formulations were prepared. The coatings were tested at 500 °C for one hour and physically were found very stable and well bound with the steel substrate. The morphology was studied by Scanning Electron Microscopy (SEM). The char composition was analysed by X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. EG above than 10.8wt% expands the char abruptly with uniform network structure and affect the outer surface of the char.

  16. Ash liberation from included minerals during combustion of pulverized coal: the relationship with char structure and burnout

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.; Wall, T.; Liu, G.; Bryant, G. [University of Newcastle, Callaghan, NSW (Australia). CRC for Black Coal Utilization and Dept. of Chemical Engineering

    1999-12-01

    In this study, the float fraction ({lt} specific gravity of 2.0) of a size cut (63-90 {mu}m) bituminous coal was combusted in a drop tube furnace (DTF) at a gas temperature of 1300{degree}C under an atmosphere of air, to investigate the ash liberation at five coal burnoff levels (35.5%, 54.3%, 70.1%, 87.1% and 95.6%). The data indicated that char structure determines the ash liberation at different burnoff levels. Fragmentation of porous char was found to be the determinative mechanism for formation of fine ash during the early and middle stages of char combustion, while coalescence of included mineral matter determines the coarse ash formed in the later stages of combustion. The investigation confirmed that the char morphology and structure play a key role in determining char fragmentation, char burnout history, and the ash liberation during combustion. 35 refs., 5 figs., 2 tabs.

  17. Computational investigations of low-emission burner facilities for char gas burning in a power boiler

    Science.gov (United States)

    Roslyakov, P. V.; Morozov, I. V.; Zaychenko, M. N.; Sidorkin, V. T.

    2016-04-01

    Various variants for the structure of low-emission burner facilities, which are meant for char gas burning in an operating TP-101 boiler of the Estonia power plant, are considered. The planned increase in volumes of shale reprocessing and, correspondingly, a rise in char gas volumes cause the necessity in their cocombustion. In this connection, there was a need to develop a burner facility with a given capacity, which yields effective char gas burning with the fulfillment of reliability and environmental requirements. For this purpose, the burner structure base was based on the staging burning of fuel with the gas recirculation. As a result of the preliminary analysis of possible structure variants, three types of early well-operated burner facilities were chosen: vortex burner with the supply of recirculation gases into the secondary air, vortex burner with the baffle supply of recirculation gases between flows of the primary and secondary air, and burner facility with the vortex pilot burner. Optimum structural characteristics and operation parameters were determined using numerical experiments. These experiments using ANSYS CFX bundled software of computational hydrodynamics were carried out with simulation of mixing, ignition, and burning of char gas. Numerical experiments determined the structural and operation parameters, which gave effective char gas burning and corresponded to required environmental standard on nitrogen oxide emission, for every type of the burner facility. The burner facility for char gas burning with the pilot diffusion burner in the central part was developed and made subject to computation results. Preliminary verification nature tests on the TP-101 boiler showed that the actual content of nitrogen oxides in burner flames of char gas did not exceed a claimed concentration of 150 ppm (200 mg/m3).

  18. Char characterization and DTF assays as tools to predict burnout of coal blends in power plants

    Energy Technology Data Exchange (ETDEWEB)

    C. Ulloa; A.G. Borrego; S. Helle; A.L. Gordon; X. Garcia [Universidad de Concepcion, Concepcion (Chile). Departamento de Ingenieria Quimica

    2005-02-01

    The aim of this study is to predict efficiency deviations in the combustion of coal blends in power plants. Combustion of blends, as compared to its single coals, shows that for some blends the behavior is non-additive in nature. Samples of coal feed and fly ashes from combustion of blends at two power plants, plus chars of the parent coals generated in a drop-tube furnace (DTF) at temperatures and heating rates similar to those found in the industrial boilers were used. Intrinsic kinetic parameters, burning profiles and petrographic characteristics of these chars correlated well with the burnout in power plants and DTF experiments. The blend combustion in a DTF reproduces both positive and negative burnout deviations from the expected weighted average. These burnout deviations have been previously attributed to parallel or parallel-series pathways of competition for oxygen. No deviations were found for blends of low rank coals of similar characteristics yielding chars close in morphology, optical texture and reactivity. Negative deviations were found for blends of coals differing moderately in rank and were interpreted as associated with long periods of competition. In this case, fly-ashes were enriched in material derived from the least reactive char, but also unburnt material attributed to the most reactive char was identified. Improved burnout compared to the weighted average was observed for blends of coals very different in rank, and interpreted as the result of a short interaction period, followed by a period where the less reactive char burns under conditions that are more favorable to its combustion. In this case, only unburned material from the least reactive char was identified in the fly-ashes. 20 refs., 9 figs., 5 tabs.

  19. Gasification of the char derived from distillation of granulated scrap tyres.

    Science.gov (United States)

    López, Félix A; Centeno, Teresa A; Alguacil, Francisco José; Lobato, Belén; López-Delgado, Aurora; Fermoso, Javier

    2012-04-01

    This work reports the effect of pressure on the steam/oxygen gasification at 1000°C of the char derived from low temperature-pressure distillation of granulated scrap tyres (GST). The study was based on the analysis of gas production, carbon conversion, cold gas efficiency and the high heating value (HHV) of the product. For comparison, similar analyses were carried out for the gasification of coals with different rank. In spite of the relatively high ash (≈12 wt.%) and sulphur (≈3 wt.%) contents, the char produced in GST distillation can be regarded as a reasonable solid fuel with a calorific value of 34MJkg(-1). The combustion properties of the char (E(A)≈50 kJ mol(-1)), its temperature of self-heating (≈264°C), ignition temperature (≈459°C) and burn-out temperature (≈676°C) were found to be similar to those of a semi-anthracite. It is observed that the yield, H(2) and CO contents and HHV of the syngas produced from char gasification increase with pressure. At 0.1 MPa, 4.6 Nm(3)kg(char)(-1) of syngas was produced, containing 28%v/v of H(2) and CO and with a HHV around 3.7 MJ Nm(-3). At 1.5 MPa, the syngas yield achieved 4.9N m(3)kg(char)(-1) with 30%v/v of H(2)-CO and HHV of 4.1 MJ Nm(-3). Carbon conversion significantly increased from 87% at 0.1 MPa to 98% at 1.5 MPa. It is shown that the char derived from distillation of granulated scrap tyres can be further gasified to render a gas of considerable heating value, especially when gasification proceeds at high pressure.

  20. Structural ordering of coal char during heat treatment and its impact on reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Feng, B.; Bhatia, S.K.; Barry, J.C.

    2002-07-01

    The effect of heat treatment on the structure of an Australian semi-anthracite char was studied between 850-1150{sup o}C using XRD, HRTEM, and electrical resistivity techniques. It was found that the carbon crystallite size in the char does not change during heat treatment, for both the raw coal and its ash-free derivative obtained by acid treatment. However, the fraction of the organized carbon in the raw coal chars, determined by XRD, increased with increase of heat treatment time and temperature, while that for the ash-free coal chars remained unchanged. This suggests the occurrence of catalytic ordering during heat treatment. Electrical resistivity of the raw coal chars decreased with heat treatment, while that of the ash-free coal chars did not vary. High resolution transmission electron micrographs depicted well-organized carbon layers surrounding iron particles. The fraction of organized carbon attains an apparent equilibrium value that increases with increase in temperature. Good temperature-independent correlation was found between the electrical resistivity and the organized carbon fraction, indicating that electrical resistivity is structure sensitive. These results suggest that the thermal deactivation is the result of a crystallite-perfecting process, which is effectively catalyzed by the inorganic matter in the coal char. It is concluded that the process is diffusion controlled, most likely involving transport of iron in the inter-crystallite nanospaces in the temperature range studied. The activation energy of this transport process is found to be low, which is corroborated by model-free correlation of the temporal variation of organized carbon fraction as well as electrical resistivity data using the superposition method, and is suggestive of surface transport of iron.

  1. Combinations of synergistic interactions and additive behavior during the co-oxidation of chars from lignite and biomass

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H.; Yaman, S. [Istanbul Technical University, Chemical and Metallurgical Engineering Faculty, Chemical Engineering Department, 34469, Maslak, Istanbul (Turkey)

    2008-02-15

    The aim of this study is to investigate the co-combustion behavior of two different pyrolytic chars. For this purpose, Elbistan lignite and woody shells of hazelnut were pyrolysed in a tube furnace by heating to 900 C with a heating rate of 40 C min{sup -} {sup 1} under dynamic nitrogen flow of 400 mL min{sup -} {sup 1} to obtain pyrolytic char. These chars were mixed to obtain blends having the biomass char in the ratios of 5, 10, and 20 wt.%. Non-isothermal DTA and TGA profiles of the chars were obtained from ambient to 900 C with a heating rate of 40 C min{sup -} {sup 1} under the static ambient atmosphere. DTA and TGA profiles of the blend chars were interpreted considering the thermal characteristics such as ignition point, burnout at a given temperature, maximum burning rate, the end of combustion etc. Relations between the fraction of the biomass char in the blends and the thermal behavior of the blends were evaluated according to the synergistic approach. It was found that addition of biomass char led to important variations in some thermal properties which can not be explained by the additive behavior. However it can be concluded in general that the combinations of synergistic interactions and additive behavior govern the thermal properties of the blend chars during co-oxidation. (author)

  2. Ash of palm empty fruit bunch as a natural catalyst for promoting the CO₂ gasification reactivity of biomass char.

    Science.gov (United States)

    Lahijani, Pooya; Zainal, Zainal Alimuddin; Mohamed, Abdul Rahman; Mohammadi, Maedeh

    2013-03-01

    Palm empty fruit bunch ash (EFB-ash) was used as a natural catalyst, rich in potassium to enhance the CO2 gasification reactivity of palm shell char (PS-char). Various EFB-ash loadings (ranging from 0 to 12.5wt.%) were implemented to improve the reactivity of PS-char during CO2 gasification studies using thermogravimetric analysis. The achieved results explored that the highest gasification reactivity was devoted to 10% EFB-ash loaded char. The SEM-EDS and XRD analyses further confirmed the successful loading of EFB-ash on PS-char which contributed to promoting the gasification reactivity of char. Random pore model was applied to determine the kinetic parameters in catalytic gasification of char at various temperatures of 800-900°C. The dependence of char reaction rate on gasification temperature resulted in a straight line in Arrhenius-type plot, from which the activation energy of 158.75kJ/mol was obtained for the catalytic char gasification.

  3. Chromosomal characteristics and distribution of rDNA sequences in the brook trout Salvelinus fontinalis (Mitchill, 1814).

    Science.gov (United States)

    Śliwińska-Jewsiewicka, A; Kuciński, M; Kirtiklis, L; Dobosz, S; Ocalewicz, K; Jankun, Malgorzata

    2015-08-01

    Brook trout Salvelinus fontinalis (Mitchill, 1814) chromosomes have been analyzed using conventional and molecular cytogenetic techniques enabling characteristics and chromosomal location of heterochromatin, nucleolus organizer regions (NORs), ribosomal RNA-encoding genes and telomeric DNA sequences. The C-banding and chromosome digestion with the restriction endonucleases demonstrated distribution and heterogeneity of the heterochromatin in the brook trout genome. DNA sequences of the ribosomal RNA genes, namely the nucleolus-forming 28S (major) and non-nucleolus-forming 5S (minor) rDNAs, were physically mapped using fluorescence in situ hybridization (FISH) and primed in situ labelling. The minor rDNA locus was located on the subtelo-acrocentric chromosome pair No. 9, whereas the major rDNA loci were dispersed on 14 chromosome pairs, showing a considerable inter-individual variation in the number and location. The major and minor rDNA loci were located at different chromosomes. Multichromosomal location (3-6 sites) of the NORs was demonstrated by silver nitrate (AgNO3) impregnation. All Ag-positive i.e. active NORs corresponded to the GC-rich blocks of heterochromatin. FISH with telomeric probe showed the presence of the interstitial telomeric site (ITS) adjacent to the NOR/28S rDNA site on the chromosome 11. This ITS was presumably remnant of the chromosome rearrangement(s) leading to the genomic redistribution of the rDNA sequences. Comparative analysis of the cytogenetic data among several related salmonid species confirmed huge variation in the number and the chromosomal location of rRNA gene clusters in the Salvelinus genome.

  4. Effect of Pyrolysis Temperature on Characteristics of Biomass Char and Coal Char%热解温度对生物质和煤成焦特性的影响

    Institute of Scientific and Technical Information of China (English)

    米翠丽; 樊孝华; 魏刚; 马登卿; 张利孟; 王学斌

    2014-01-01

    以麦秆、橡树木屑和华亭烟煤为原料,研究热解产物的理化特性并讨论燃料种类和热解温度对其的影响。采用BET、SEM-EDS、XRD和TGA对其进行分析表征。结果表明:在600~1000℃的温度范围内,煤焦的比表面积和孔隙容积随热解温度增加而增大,而木屑焦的变化不明显,麦秆焦在800℃时比表面积和孔隙容积最大,更高温度则发生烧结;焦样中C元素含量随热解温度升高而增加,而H元素和O元素随之降低,麦秆焦的着火特性优于木屑焦和煤焦。木屑焦和煤焦的着火特性随热解温度升高而变差,而麦秆焦在800℃具有最佳的着火特性。%The effects of fuel type and pyrolysis temperature on the physicochemical properties of coal char( C-char)and biomass char were investigated with straw,oak sawdust,and Huating bituminous coal as raw materials. BET,SEM-EDS,XRD,and TGA were used to analyze the coke specimens. Results show that the BET surface area and porous volume of C-char increase as the pyrolysis temperature increases,whereas those of wood char( W-char)insignificantly change,from 600 to 1 000 ℃. Straw char ( S-char)has the largest surface area and pore volume at 800 ℃ as sintering occurs at higher temperatures. As the pyrolysis temperature increases,the C content of char increases and its H and O contents decrease. The ignition characteristic of S-char is superior to those of W-char and C-char. The ignition characteristics of Wood-char and C-char decrease with the increase of pyrolysis temperature. Straw-char exhibits the best ignition characteristic at 800℃.

  5. CFD Simulation of Entrained Flow Gasification With Improved Devolatilization and Char Consumption Submodels

    KAUST Repository

    Kumar, Mayank

    2009-01-01

    In this work, we use a CFD package to model the operation of a coal gasifier with the objective of assessing the impact of devolatilization and char consumption models on the accuracy of the results. Devolatilization is modeled using the Chemical Percolation Devolitilization (CPD) model. The traditional CPD models predict the rate and the amount of volatiles released but not their species composition. We show that the knowledge of devolatilization rates is not sufficient for the accurate prediction of char consumption and a quantitative description of the devolatilization products, including the chemical composition of the tar, is needed. We incorporate experimental data on devolatilization products combined with modeling of the tar composition and reactions to improve the prediction of syngas compositions and carbon conversion. We also apply the shrinking core model and the random pore model to describe char consumption in the CFD simulations. Analysis of the results indicates distinct regimes of kinetic and diffusion control depending on the particle radius and injection conditions for both char oxidation and gasification reactions. The random pore model with Langmuir-Hinshelwood reaction kinetics are found to be better at predicting carbon conversion and exit syngas composition than the shrinking core model with Arrhenius kinetics. In addition, we gain qualitative and quantitative insights into the impact of the ash layer surrounding the char particle on the reaction rate. Copyright © 2010 by ASME.

  6. Evaluación de la reducibilidad de un mineral de hierro usando char como reductor

    Directory of Open Access Journals (Sweden)

    Yenny Rubiela Hernández, Carlos Alberto Sandoval Fonseca, Claudia Inés Sánchez Buitrago

    2011-05-01

    Full Text Available Muestra los ensayos de  reduciblidad  realizados en un hornotipo Linder a un mineral de hierro del municipio de Ubalá(departamento de Cundinamarca, Colombia, usando comoreductor un char. Se  indican las características del mineralde  hierro  de Ubalá, de  los  carbones  empleados para  laproducción del char y de la caliza, así como los ensayos dereducibilidad. Para la caracterización de  las materias primasy del char, como producto  final, se aplicaron normas ASTM.En  la producción de  los char se utilizaron  los hornos decoquización  tipo Cerchar  y  tipo  colmena  de  la Uptc  enSamacá  (Boyacá. Los ensayos de reducibilidad se hicieronbajo  los mismos parámetros de operación utilizados concarbón como reductor, y los resultados obtenidos dejan verque el mineral de hierro de Ubalá es reducible en menorporcentaje con char. Sin embargo, por  los grandes beneficiospara el medioambiente que se obtienen trabajando con elchar, no se descarta  la posibilidad de utilizarlo como posiblesustituto del carbón en el proceso de reducción directa.

  7. Abundant and stable char residues in soils: implications for soil fertility and carbon sequestration.

    Science.gov (United States)

    Mao, J-D; Johnson, R L; Lehmann, J; Olk, D C; Neves, E G; Thompson, M L; Schmidt-Rohr, K

    2012-09-04

    Large-scale soil application of biochar may enhance soil fertility, increasing crop production for the growing human population, while also sequestering atmospheric carbon. But reaching these beneficial outcomes requires an understanding of the relationships among biochar's structure, stability, and contribution to soil fertility. Using quantitative (13)C nuclear magnetic resonance (NMR) spectroscopy, we show that Terra Preta soils (fertile anthropogenic dark earths in Amazonia that were enriched with char >800 years ago) consist predominantly of char residues composed of ~6 fused aromatic rings substituted by COO(-) groups that significantly increase the soils' cation-exchange capacity and thus the retention of plant nutrients. We also show that highly productive, grassland-derived soils in the U.S. (Mollisols) contain char (generated by presettlement fires) that is structurally comparable to char in the Terra Preta soils and much more abundant than previously thought (~40-50% of organic C). Our findings indicate that these oxidized char residues represent a particularly stable, abundant, and fertility-enhancing form of soil organic matter.

  8. Tar reduction in pyrolysis vapours from biomass over a hot char bed.

    Science.gov (United States)

    Gilbert, P; Ryu, C; Sharifi, V; Swithenbank, J

    2009-12-01

    The behaviour of pyrolysis vapours over char was investigated in order to maximise tar conversion for the development of a new fixed bed gasifier. Wood samples were decomposed at a typical pyrolysis temperature (500 degrees C) and the pyrolysis vapours were then passed directly through a tar cracking zone in a tubular reactor. The product yields and properties of the condensable phases and non-condensable gases were studied for different bed lengths of char (0-450 mm), temperatures (500-800 degrees C), particle sizes (10 and 15 mm) and nitrogen purge rates (1.84-14.70 mm/s). The carbon in the condensable phases showed about 66% reduction by a 300 mm long char section at 800 degrees C, compared to that for pyrolysis at 500 degrees C. The amount of heavy condensable phase decreased with increasing temperature from about 18.4 wt% of the biomass input at 500 degrees C to 8.0 wt% at 800 degrees C, forming CO, H(2) and other light molecules. The main mode of tar conversion was found to be in the vapour phase when compared to the results without the presence of char. The composition of the heavy condensable phase was simplified into much fewer secondary and tertiary tar components at 800 degrees C. Additional measures were required to maximise the heterogeneous effect of char for tar reduction.

  9. Effects of Hybrid Fibre Reinforcement on Fire Resistance Performance and Char Morphology of Intumescent Coating

    Directory of Open Access Journals (Sweden)

    Amir N.

    2016-01-01

    Full Text Available Recent researches of fire retardant intumescent coatings reinforced by single Rockwool and single glass wool fibre at various weight percentages and lengths showed some improvements to the mechanical properties of the coatings and the char produced. Therefore, in this research the fibres were combined together in intumescent coating formulation at several weight percentages and fibre lengths to study their effects towards fire resistance performance and char morphology. The hybrid fibre reinforced intumescent coatings were subjected to two types of fire tests; Bunsen burner at 1000°C and the electric furnace at 800°C for 1 hour, respectively. Steel temperature of the coated samples during Bunsen burner test was recorded to determine the fire resistance performance. Thermal stability of the intumescent coatings and chars was determined by Thermogravimetric Analysis (TGA. The morphology of the coatings and char was then examined by using Scanning Electron Microscopy (SEM and Energy Dispersive Spectrometry (EDS was conducted to obtain elemental composition of the samples. This research concluded that long-hybrid fibre at 12-mm length and 0.6% fibre-weight produced the top performing hybrid fibre intumescent formulation. The hybrid fibres form survived at elevated temperature, hence helped to provide structure and strengthen the char with the highest fire resistance was recorded at steel temperature of 197°C.

  10. NO formation during oxy-fuel combustion of coal and biomass chars

    DEFF Research Database (Denmark)

    Zhao, Ke; Jensen, Anker Degn; Glarborg, Peter

    2014-01-01

    The yields of NO from combustion of bituminous coal, lignite, and biomass chars were investigated in O2/N2 and O2/CO 2 atmospheres. The experiments were performed in a laboratory-scale fixed-bed reactor in the temperature range of 850-1150 °C. To minimize thermal deactivation during char...... preparation, the chars were generated by in situ pyrolysis at the reaction temperature. The NO yield clearly decreased and the CO yield increased when the atmosphere was altered from O2/N 2 to O2/CO2 at 850 °C, but only small differences in NO and CO yields were observed between the two atmospheres at 1050......-1150 °C. To examine how CO influences the NO yield, the effect of CO on NO reduction over char as well as NO reduction by CO over ash was investigated in the fixed-bed reactor. Furthermore, the influence of CO on the homogeneous oxidation of HCN, possibly a product of the char-N oxidation, was evaluated...

  11. Competitive biodegradation of dichlobenil and atrazine coexisting in soil amended with a char and citrate

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Yuping; Pang Hui; Zhou Zunlong [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Zhang Ping [Department of Civil Engineering, University of Minnesota, Minneapolis, MN 55455 (United States); Feng Yucheng [Department of Agronomy and Soils, Auburn University, Auburn, AL 36849 (United States); Sheng, G. Daniel, E-mail: dansheng@zjut.edu.c [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China)

    2009-11-15

    The role of char nutrients in the biodegradation of coexisting dichlobenil and atrazine in a soil by their respective bacterial degraders, DDN and ADP, was evaluated. Under growing conditions, their degradation in soil extract was slow with <40% and <20% degraded within 64 h, respectively. The degradation in extracts and slurries of char-amended solids increased with increasing char content, due to nutritional stimulation on microbial activities. By supplementing soil extract with various major nutrients, the measured degradation demonstrated that P was the exclusive limiting nutrient. The reduction in the degradation of coexisting dichlobenil and atrazine resulted apparently from the competitive utilization of P by DDN and ADP. With a shorter lag phase, ADP commenced growing earlier than DDN with the advantage of utilizing P first in insufficient supply. This resulted in an inhibition on the growth of DDN and thus suppression on dichlobenil degradation. - Competitive utilization of char nutrients by bacterial degraders resulted in the preferential biodegradation of atrazine over dichlobenil in a soil containing a wheat-straw-derived char.

  12. Adsorption characteristics of SO{sub 2}, NO by steam activated biomass chars

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Fei; Shu, Tong; Wang, Kuan; Lu, Ping [Nanjing Normal Univ. (China). School of Energy and Mechanical Engineering

    2013-07-01

    Wheat straw and rice husk collected from the suburb of Nanjing, China, were prepared to different kinds of steam activated biomass-based chars, and the adsorption characteristics of the biomass-based chars was carried out in a fixed bed reactor. The specific surface area and pore structure of different biomass chars were measured by nitrogen adsorption-desorption analysis instrument at 77K. The effects of biomass type, pyrolysis temperature, heating rate, activation temperature and concentration of SO{sub 2}, NO on the adsorption efficiency of SO{sub 2}, NO were analyzed. The results indicated that the steam activation has significant effects on the specific surface area, total pore volume and micro-morphology of biomass chars by improving the internal structure. The adsorption efficiency of SO{sub 2}, NO increased with the decreasing of SO{sub 2}, NO concentration in the experimental range. The optimal condition of char preparation (873K, fast pyrolysis) and steam activation (1,073K) was proposed based on the adsorption efficiency and adsorption volume of SO{sub 2}, NO. It builds a theoretical basis for industrial applications of biomass.

  13. Bitumen on Water: Charred Hay as a PFD (Petroleum Flotation Device

    Directory of Open Access Journals (Sweden)

    Nusrat Jahan

    2015-10-01

    Full Text Available Global demand for petroleum keeps increasing while traditional supplies decline. One alternative to the use of conventional crude oils is the utilization of Canadian bitumen. Raw bitumen is a dense, viscous, semi-liquid that is diluted with lighter crude oil to permit its transport through pipelines to terminals where it can then be shipped to global markets. When spilled, it naturally weathers to its original form and becomes dense enough to sink in aquatic systems. This severely limits oil spill recovery and remediation options. Here we report on the application of charred hay as a method for modifying the surface behavior of bitumen in aquatic environments. Waste or surplus hay is abundant in North America. Its surface can easily be modified through charring and/or chemical treatment. We have characterized the modified and charred hay using solid-state NMR, contact angle measurements and infrared spectroscopy. Tests of these materials to treat spilled bitumen in model aquatic systems have been undertaken. Our results indicate that bitumen spills on water will retain their buoyancy for longer periods after treatment with charred hay, or charred hay coated with calcium oxide, improving recovery options.

  14. A Study on Recycling of Spent Mushroom Substrate to Prepare Chars and Activated Carbon

    Directory of Open Access Journals (Sweden)

    Yuhui Ma

    2014-05-01

    Full Text Available Chars were obtained from spent mushroom substrate (SMS via pyrolysis. It was found that as the pyrolysis temperature increased from 400 to 700 °C, the char yield decreased from 45.10 to 33.79 wt.% and the higher heating value increased from 17.32 to 22.72 MJ/kg. The largest BET surface area (13 m2/g was created at 500 °C. Hydrogen atoms were continuously lost during pyrolysis, whereas oxygen atoms were difficult to eliminate. Whewellite, calcite, lime, and quartz were the minerals in the chars, and their forms and crystallinity changed with changing pyrolysis temperature. Activated carbon with a BET surface area of 1023 m2/g and a total pore volume of 0.595 cm3/g was obtained from the char prepared at 500 °C. Its characteristics were studied by N2-adsorption, Fourier transform infrared spectroscopy (FTIR, and X-ray diffraction (XRD. The pyrolysis and KOH-activation processes were investigated by thermogravimetric analysis (TGA. The results showed that the pyrolysis of SMS occurred primarily between 217 and 375 °C and that the energies needed for the pyrolysis reactions were relatively low due to the prior mushroom cultivation. Furthermore, lignin was incompletely decomposed in the char prepared at 500 °C, and KOH suppressed tar evolution and reduced the energy needed to decompose the residual lignin during activation.

  15. Temperature, pressure and light data collected by attached Archival Transmitting Tags to Salvelinus malma (Dolly Varden trout) in the Wulik River, Alaska, during 2012-06 to 2013-10 (NODC Accession 0119954)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains data collected by electronic tags (Pop-up Satellite Archival Transmitting) attached to Salvelinus malma (Dolly Varden trout) in the Wulik...

  16. Baetis (Baetis) cypronyx sp. n., a new species of the Baetis alpinus species-group (Insecta, Ephemeroptera, Baetidae) from Cyprus, with annotated checklist of Baetidae in the Mediterranean islands

    Science.gov (United States)

    Godunko, Roman J.; Soldán, Tomáš; Staniczek, Arnold H.

    2017-01-01

    Abstract A detailed description of the larvae of Baetis (Baetis) cypronyx sp. n., a representative of the Baetis alpinus species-group within the mayfly family Baetidae, is provided, including a differential diagnosis with regard to closely related species of the group, especially Baetis melanonyx (Pictet, 1843) and Baetis baroukianus Thomas & Dia, 1984. The new species is mainly distinguished by mouthparts (i.e. the shape and setation of labrum, maxillary and labial palps, details of paraglossae and mandibular incisors), setation of legs and abdominal terga, and length of paracercus. All available data on the biology of this putative endemic species of Cyprus are summarized. Annotated distributional data of the 33 species of Baetidae so far recorded from the Mediterranean islands are given, including new records and also including first data from Malta. PMID:28144182

  17. Development of carbon dioxide adsorbent from rice husk char

    Science.gov (United States)

    Abang, S.; Janaun, J.; Anisuzzaman, S. M.; Ikhwan, F. S.

    2016-06-01

    This study was mainly concerned about the development of carbon dioxide (CO2) adsorbent from rice husk (RH). Several chemical treatments were used to produce activated rice husk char (RHAC) from RH. Initially the RH was refluxed with 3M of sodium hydroxide (NaOH) solution, activation followed by using 0.5M of zinc chloride (ZnCl2) solution and finally acidic treatment by using 0.1M of hydrochloric acid (HCl). Then, the RHAC was functionalized by using 3-chloropropylamine hydrochloride (3-CPA) and noted as RHN. RHN samples were characterized with scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), fourier transform infrared spectroscopy (FTIR). Based on the SEM, the RHN sample had a large pore diameter compared to RH sample after being treated. Based on MIP data, the average pore diameter between RH and RHAC samples were increased significantly from 0.928 microns to 1.017 microns. The RHN sample also had higher total porosity (%) compared to RHAC and RH (58.45%, 47.82% and 45.57% respectively). The total specific surface area of the sample was much increasing from RHO to RHAC (29.17 m2/g and 62.94 m2/g respectively) and slightly being decreasing from RHAC to RHN (58.88 m2/g). FTIR result showed the present of weak band at 1587 cm-1 which demonstrating of the amine group present on the sample. The CO2 capture result showed that the decreasing of operating temperature can increase the breakthrough time of CO2 capture. On the contrary decreasing of CO2 gas flow rate can increase the breakthrough time of CO2 capture. The highest total amount of CO2 adsorbed was 25338.57 mg of CO2/g of RHN sample by using 100 mL/min of gas flow rate at 30oC. Based on adsorption isotherm analysis, the Freundlich isotherm was the best isotherm to describe the CO2 adsorption on the sample.

  18. Adsorption of Pb(II by Activated Pyrolytic Char from Used Tire

    Directory of Open Access Journals (Sweden)

    Lu Ping

    2016-01-01

    Full Text Available As a renewable resource, the pyrolytic char derived from used tire has promising adsorption capacities owing to its similar structure and properties with active carbon. The purification and activation of the pyrolytic char from used tire, as well as the application of this material in the adsorption of Pb(II in water is conducted. The influences on the adsorption capacity by temperature and pH value are investigated and discussed; the adsorption thermodynamics and kinetics are also studied. The results show that the pyrolytic char from used tire has remarkable adsorption capacity for Pb(II, and the adsorption is an endothermic process complying with the Langmuir isotherm. The adsorption kinetics is a pseudo second-order reaction.

  19. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    Energy Technology Data Exchange (ETDEWEB)

    Khongkrapan, Parin; Thanompongchart, Patipat; Tippayawong, Nakorn; Kiatsiriroat, Tanongkiat [Department of Mechanical Engineering, Faculty of Engineering, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2013-07-01

    In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2) in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

  20. A simple expression for the apparent reaction rate of large wood char gasification with steam.

    Science.gov (United States)

    Umeki, Kentaro; Roh, Seon-Ah; Min, Tai-Jin; Namioka, Tomoaki; Yoshikawa, Kunio

    2010-06-01

    A simple expression for the apparent reaction rate of large wood char gasification with steam is proposed. Large char samples were gasified under steam atmosphere using a thermo-balance reactor. The apparent reaction rate was expressed as the product of the intrinsic rate and the effective factor. The effective factor was modified to include the effect of change in char diameter and intrinsic reaction rate during the reaction. Assuming uniform conversion ratio throughout a particle, the simplified reaction scheme was divided into three stages. In the initial stage, the local conversion ratio increases without particle shrinkage. In the middle stage, the particle shrinks following the shrinking core model without change in the local conversion ratio. In the final stage, the local conversion ratio increases without particle shrinkage. The validity of the modified effective value was confirmed by comparison with experimental results.

  1. Fuel gas and char from pyrolysis of waste paper in a microwave plasma reactor

    Directory of Open Access Journals (Sweden)

    Parin Khongkrapan, Patipat Thanompongchart, Nakorn Tippayawong, Tanongkiat Kiatsiriroat

    2013-01-01

    Full Text Available In this study, a microwave plasma reactor was used for pyrolysis of waste papers. The effects of different argon flow rates on char and gas generation were investigated. Changes in carbon and oxygen contents from those in paper to char were significant. Char yield of over 25 % was obtained with the heating value of about 38 MJ/kg. Average gas yield and total content of combustible fraction (CO, CH4 and H2 in the gas product were 2.56 m3/kg and 36 %, respectively. The heating value of gas product and carbon conversion efficiency of the process were maximum at 6.0 MJ/m3 and 73 %, respectively.

  2. Coal Char Derived Few-Layer Graphene Anodes for Lithium Ion Batteries

    Directory of Open Access Journals (Sweden)

    Dan Wang

    2014-08-01

    Full Text Available Few-layer graphene films were synthesized through chemical vapor deposition technique using coal char as solid carbon source. Raman spectroscopy, X-ray diffraction, transmission electron microscopy, and selected area electron diffraction were used to characterize the graphene films. The electrochemical performance of the coal char derived few layer graphene anodes for lithium ion batteries was investigated by charge/discharge curves  and  discharge  capacity  at  different  current  densities.  The  graphene  anode maintained the reversible capacity at ~0.025, 0.013, and 0.007 mAh/cm2  at a current density of 10, 30, and 50 µA/cm2, respectively. The coal char derived graphene anodes show potential applications in thin film batteries for nanoelectronics.

  3. Structural evolution of biomass char and its effect on the gasification rate

    DEFF Research Database (Denmark)

    Fatehi, Hesameddin; Bai, Xue Song

    2017-01-01

    with different radii. The model is valid for biomass chars produced under relatively low heating rates, when the original beehive structure of the biomass is not destroyed during the pyrolysis stage. The contribution of different pores with different radius is taken into account using an effectiveness factor...... during the entire conversion process. This model is used to analyze the steam gasification process of biomass char of centimeter sizes. The results from the present multi-pore model are in better agreement with experimental data than those from a corresponding single pore model. Since the multi......-pore model accommodates the detailed intra-particle transport, it is a useful basis toward developing a more predictive model for biomass char gasification....

  4. Gasification as an alternative method for the destruction of sulfur containing waste (ChemChar process)

    Energy Technology Data Exchange (ETDEWEB)

    Medcalf, B.D.; Manahan, S.E. [Univ. of Missouri, Columbia, MO (United States). Dept. of Chemistry; Larsen, D.W. [Univ. of Missouri, St. Louis, MO (United States). Dept. of Chemistry

    1998-12-31

    The behavior of a non-incinerative reductive thermal cocurrent flow gasification process (ChemChar Process) when used to treat representative sulfur compounds is reported. Gasification of 2,3-benzenedisulfonic acid, thiomorpholine, and sulfuric acid converts the sulfur in these compounds to H{sub 2}S, OCS, and elemental sulfur. The H{sub 2}S and OCS are released in the synthesis with the gas product from which they can be scrubbed, with the elemental sulfur being deposited on the char matrix. No production of sulfur dioxide was detected. Gasified sulfur products recovered amounted to 89--114% of the total sulfur present in the sulfur compounds gasified, although exact mass balances could not be obtained due to the sulfur present in the char.

  5. A solid state NMR investigation of char forming processes in polymer degradation

    CERN Document Server

    Dick, C M

    2002-01-01

    A detailed knowledge of the condensed phase chemistry occurring in polymers exposed to elevated temperatures is crucial to understanding the behaviour of polymers exposed to fire. This is particularly true when trying to reduce polymer flammability by means of promoting char-forming reactions. Until recently, however, structural information on highly crosslinked chars and their precursors has been difficult to obtain, and as a consequence many degradation workers have merely labelled degradation residues as 'intractable'. However, the application of solid state NMR techniques developed in our laboratories for the structural characterisation of coals has provided a considerable insight into the structure and chemistry of polymer chars formed under both oxidative and non-oxidative conditions. A series of polymers including poly(vinyl chloride), poly(vinyl acetate), polyurethanes, polychloropene, cis and trans polyisoprene have been studied. These polymers have been used to describe the application of quantitati...

  6. Charring temperatures are driven by the fuel types burned in a peatland wildfire

    Directory of Open Access Journals (Sweden)

    Victoria A. Hudspith

    2014-12-01

    Full Text Available Peatlands represent a globally important carbon store; however, the human exploitation of this ecosystem is increasing both the frequency and severity of fires on drained peatlands. Yet, the interactions between the hydrological conditions (ecotopes, the fuel types being burned, the burn severity, and the charring temperatures (pyrolysis intensity remain poorly understood. Here we present a post-burn assessment of a fire on a lowland raised bog in Co. Offaly, Ireland (All Saints Bog. Three burn severities were identified in the field (light, moderate, and deeply burned, and surface charcoals were taken from 17 sites across all burn severities. Charcoals were classified into two fuel type categories (either ground or aboveground fuel and the reflectance of each charcoal particle was measured under oil using reflectance microscopy. Charcoal reflectance shows a positive relationship with charring temperature and as such can be used as a temperature proxy to reconstruct minimum charring temperatures after a fire event. Resulting median reflectance values for ground fuels are 1.09 ± 0.32%Romedian, corresponding to estimated minimum charring temperatures of 447°C ± 49°C. In contrast, the median charring temperatures of aboveground fuels were found to be considerably higher, 646°C ± 73°C (3.58 ± 0.77%Romedian. A mixed-effects modelling approach was used to demonstrate that the interaction effects of burn severity, as well as ecotope classes, on the charcoal reflectance is small compared to the main effect of fuel type. Our findings reveal that the different fuel types on raised bogs are capable of charring at different temperatures within the same fire, and that the pyrolysis intensity of the fire on All Saints Bog was primarily driven by the fuel types burning, with only a weak association to the burn severity or ecotope classes.

  7. Chemical characterization of chars developed from thermochemical treatment of Kentucky bluegrass seed screenings.

    Science.gov (United States)

    Griffith, Stephen M; Banowetz, Gary M; Gady, David

    2013-08-01

    Seed mill screenings would be a considerable biofeedstock source for bioenergy and char production. Char produced from the gasification of residues resulting from cleaning of grass seed and small grains could be recycled to a cropping system as a soil amendment if chemical characterization determined that the gasification process had not produced or concentrated deleterious chemical or physical factors that might harm the environment, crop growth or yield. Previous reports have shown that char derived from the pyrolysis of a variety of biomass feedstocks has potential to enhance soil quality by pH adjustment, mineral amendment, and improved soil porosity. The objective of this research was to characterize char produced from Kentucky bluegrass seed mill screenings (KBss) by a small-scale gasification unit, operated at temperatures between 600 and 650°C, with respect to polycyclic aromatic hydrocarbons, selected heavy metals, as well as other physical and chemical characteristics, and determine its suitability for agricultural application as a soil amendment. We utilized KBss as a model for seed and grain-cleaning residues with the understanding that chemical and physical characteristics of char produced by gasification or other cleaning residues may differ based on soil and environmental conditions under which the crops were produced. Our results support the hypothesis that KBss char could be applied in a cropping system without toxic environmental consequences and serve multiple purposes, such as; recycling critical plant macro- and micro-nutrients back to existing cropland, enhancing soil carbon sequestration, managing soil pH, and improving water holding capacity. Crop field trails need to be implemented to further test these hypotheses.

  8. Considerations Based on Reaction Rate on Char Gasification Behavior in Two-stage Gasifier for Biomass

    Science.gov (United States)

    Taniguchi, Miki; Nishiyama, Akio; Sasauchi, Kenichi; Ito, Yusuke; Akamatsu, Fumiteru

    In order to develop a small-scale gasifier in which biomass can be converted to energy with high efficiency, we planned a gasification process that consists of two parts: pyrolysis part (rotary kiln) and gasification part (downdraft gasifier). We performed fundamental experiments on gasification part and discussed the appropriate conditions such as air supply location, air ratio, air temperature and hearth load. We considered the results by calculating reaction rates of representative reactions on char gasification part and found that water gas reaction is dominant in the reduction area and its behavior gives important information to decide the adequate length of the char layer.

  9. The CharXive Challenge. Regulation of global carbon cycles by vegetation fires

    CERN Document Server

    Ball, R

    2010-01-01

    It is an open, but not unanswerable, question as to how much atmospheric CO2 is sequestered globally by vegetation fires. In this work I conceptualise the question in terms of the general CharXive Challenge, discuss a mechanism by which thermoconversion of biomass may regulate the global distribution of carbon between reservoirs, show how suppression of vegetation fires by human activities may increase the fraction of carbon in the atmospheric pool, and pose three specific CharXive Challenges of crucial strategic significance to our management of global carbon cycles.

  10. Microwave Assisted Hydrolysis of Holocellulose Catalyzed with Sulfonated Char Derived from Lignin-Rich Residue

    Directory of Open Access Journals (Sweden)

    Kui Wang

    2015-01-01

    Full Text Available A microwave assisted green process has been developed for production of sugars through liquefying holocellulose catalyzed with sulfonated char derived from the lignin-rich residue produced during pretreatment of lignocellulose. Various reaction parameters including the hydrolysis temperature, hydrolysis time, catalyst content, and the ratio of water to feedstock were evaluated. The maximum sugars yield of 82.6% (based on the dry mass of holocellulose was obtained under the optimum reaction conditions. The sulfonated char showed superior catalytic performance to that of dilute sulfuric acid in converting holocellulose into sugars under microwave irradiation.

  11. ENHANCING ASPHALT RHEOLOGICAL BEHAVIOR AND AGING SUSCEPTIBILITY USING BIO-CHAR AND NANO-CLAY

    OpenAIRE

    2014-01-01

    The life expectancy of Asphalt Binder (AB) has been negatively impacted by the harsh bombardment of UV rays. UV rays cause asphalt to oxidize faster, which results in deterioration of asphalt rheological characteristics that can lead to pavement distresses. This study investigates the impact of bio-char and nano-clay of asphalt rheological properties. Two nano scale materials were used for this study were nano-clay and bio-char. Nano-clay (Cloisite 30B) is a naturally occurring inorganic mine...

  12. Comparison of high temperature chars of wheat straw and rice husk with respect to chemistry, morphology and reactivity

    DEFF Research Database (Denmark)

    Trubetskaya, Anna; Jensen, Peter Arendt; Jensen, Anker Degn

    2016-01-01

    Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at hightemperatures(1000e1500) C. The collected char was analyzed using X-ray diffractometry, N2-adsorption,scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid-statenucle......Fast pyrolysis of wheat straw and rice husk was carried out in an entrained flow reactor at hightemperatures(1000e1500) C. The collected char was analyzed using X-ray diffractometry, N2-adsorption,scanning electron microscopy, particle size analysis with CAMSIZER XT, 29Si and 13C solid......-statenuclear magnetic resonance spectroscopy and thermogravimetric analysis to investigate the effect ofinorganic matter on the char morphology and oxygen reactivity. The silicon compounds were dispersedthroughout the turbostratic structure of rice husk char in an amorphous phase with a low meltingtemperature (z730 C......), which led to the formation of a glassy char shell, resulting in a preserved particlesize and shape of chars. The high alkali content in the wheat straw resulted in higher char reactivity,whereas the lower silicon content caused variations in the char shape from cylindrical to near...

  13. Reactivity of chars prepared from the pyrolysis of a Victorian lignite under a wide range of conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wu, H.; Mody, D.; Li, C.; Hayashi, J.; Chiba, T. [Monash University, Vic. (Australia). CRC for Clean Power from Lignite, Dept. of Chemical Engineering

    2000-07-01

    A Loy Yang lignite sample was pyrolysed under a wide range of experimental conditions using a wire-mesh reactor, a fluidised-bed reactor, a drop-tube reformer and a thermogravimetric analyser (TGA). The reactivity of these char samples in CO{sub 2} and air was measured in the TGA as well as in the fluidised-bed reactor. A sample prepared by the physical impregnation of NaCl into the lignite was also used in order to investigate the effect of NaCl in the lignite on the reactivity of the resulting char. Our experimental results indicate that, due to the volatilisation of a substantial fraction of Na in the lignite substrate during pyrolysis, the true catalytic activity of the Na in the lignite substrate should be evaluated by measuring the sodium content in the char after pyrolysis. The char reactivity measured in situ in the fluidised-bed reactor was compared with that of the same char measured separately in the TGA after re-heating the char sample to the same temperature as that in the fluidised-bed. It was found that the re-heating of the char in the TGA reduced the char reactivity.

  14. Clean, premium-quality chars: Demineralized and carbon enriched. Quarterly report, September 1, 1991--Novemer 30, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.

    1992-01-03

    The goal of this project is to develop a bench-scale procedure to produce clean, desulfurized, premium-quality chars from the Illinois basin coals. This goal is achieved by utilizing the effective capabilty of smectites in combination with methane to manipulate the char yields. The major objectives are: to determine the optimum water- ground particle size for the maximum reduction of pyrite and minerals by the selective-bitumen agglomeration process; to evaluate the type of smectite and its interlamellar cation which enhances the premium-quality char yields; to find the mode of dispersion of smectites in clean coal which retards the agglomeration of char during mild gasification; to probe the conditions that maximize the desulfurized clean-char yields under a combination of methane+oxygen or helium+oxygen; to characterize and accomplish a material balance of chars, liquids, and gases produced during mild gasification; to identify the conditions which reject dehydrated smectites from char by the gravitational separation technique; and to determine the optimum seeding of chars with polymerized maltene for flammability and transportation.

  15. The influence of fine char particles burnout on bed agglomeration during the fluidized bed combustion of a biomass fuel

    Energy Technology Data Exchange (ETDEWEB)

    Scala, Fabrizio; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, CNR, P.le V. Tecchio, 80-80125 Naples (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le V. Tecchio, 80-80125 Naples (Italy)

    2003-11-15

    The combustion of biomass char in a bubbling fluidized bed is hereby addressed, with specific reference to the influence that the combustion of fine char particles may exert on ash deposition and bed agglomeration phenomena. Experiments of steady fluidized bed combustion (FBC) of powdered biomass were carried out with the aim of mimicking the postcombustion of attrited char fines generated in the fluidized bed combustion of coarse char. Experimental results showed that the char elutriation rate is much smaller than expected on the basis of the average size of the biomass powder and of the carbon loading in the combustor. Samples of bed material collected after prolonged operation of the combustor were characterized by scanning electron microscopy (SEM)-EDX analysis and revealed the formation of relatively coarse sand-ash-carbon aggregates. The phenomenology is consistent with the establishment of a char phase attached to the bed material as a consequence of adhesion of char fines onto the sand particles. Combustion under sound-assisted fluidization conditions was also tested. As expected, enhancement of fines adhesion on bed material and further reduction of the elutriation rate were observed. Experimental results are interpreted in the light of a simple model which accounts for elutriation of free fines, adhesion of free fines onto bed material and detachment of attached fines by attrition of char-sand aggregates. Combustion of both free and attached char fines is considered. The parameters of the model are assessed on the basis of the measured carbon loadings and elutriation rates. Model computations are directed to estimate the effective size and the peak temperature of char-sand aggregates. The theoretical estimates of the effective aggregate size match fairly well those observed in the experiments.

  16. Preference for cannibalism and ontogenetic constraints in competitive ability of piscivorous top predators.

    Science.gov (United States)

    Byström, Pär; Ask, Per; Andersson, Jens; Persson, Lennart

    2013-01-01

    Occurrence of cannibalism and inferior competitive ability of predators compared to their prey have been suggested to promote coexistence in size-structured intraguild predation (IGP) systems. The intrinsic size-structure of fish provides the necessary prerequisites to test whether the above mechanisms are general features of species interactions in fish communities where IGP is common. We first experimentally tested whether Arctic char (Salvelinus alpinus) were more efficient as a cannibal than as an interspecific predator on the prey fish ninespine stickleback (Pungitius pungitius) and whether ninespine stickleback were a more efficient competitor on the shared zooplankton prey than its predator, Arctic char. Secondly, we performed a literature survey to evaluate if piscivores in general are more efficient as cannibals than as interspecific predators and whether piscivores are inferior competitors on shared resources compared to their prey fish species. Both controlled pool experiments and outdoor pond experiments showed that char imposed a higher mortality on YOY char than on ninespine sticklebacks, suggesting that piscivorous char is a more efficient cannibal than interspecific predator. Estimates of size dependent attack rates on zooplankton further showed a consistently higher attack rate of ninespine sticklebacks compared to similar sized char on zooplankton, suggesting that ninespine stickleback is a more efficient competitor than char on zooplankton resources. The literature survey showed that piscivorous top consumers generally selected conspecifics over interspecific prey, and that prey species are competitively superior compared to juvenile piscivorous species in the zooplankton niche. We suggest that the observed selectivity for cannibal prey over interspecific prey and the competitive advantage of prey species over juvenile piscivores are common features in fish communities and that the observed selectivity for cannibalism over interspecific prey has

  17. Oxy-fuel combustion of millimeter-sized coal char: Particle temperatures and NO formation

    DEFF Research Database (Denmark)

    Brix, Jacob; Navascués, Leyre Gómez; Nielsen, Joachim Bachmann;

    2013-01-01

    In this work, differences in particle temperature and NO yield during char oxidation in O2/N2 and O2/CO2 atmospheres, respectively, have been examined. A laboratory scale fixed bed reactor, operated isothermally at 1073 K, was used for combustion of millimeter-sized lignite and bituminous coal ch...

  18. Derivation of heat value of coke/char from proximate analysis

    Energy Technology Data Exchange (ETDEWEB)

    Roy, R.R.P. (and others)

    From experimental data on high-, medium- and low-temperature cokes or chars, the following formulae were derived: gross CV (kcal/kg) 80(FC) + 76(VM); hydrogen content 0.224(VM). All values are on the air-dried basis.

  19. Modeling the temperature in coal char particle during fluidized bed combustion

    Energy Technology Data Exchange (ETDEWEB)

    Vasilije Manovic; Mirko Komatina; Simeon Oka [University of Belgrade, Belgrade (Serbia)

    2008-05-15

    The temperatures of a coal char particle in hot bubbling fluidized bed (FB) were analyzed by a model of combustion. The unsteady model includes phenomena of heat and mass transfer through a porous char particle, as well as heterogeneous reaction at the interior char surface and homogeneous reaction in the pores. The parametric analysis of the model has shown that above 550{sup o}C combustion occurs under the regime limited by diffusion. The experimental results of temperature measurements by thermocouple in the particle center during FB combustion at temperatures in the range 590-710{sup o}C were compared with the model predictions. Two coals of different rank were used: lignite and brown coal, with particle size in the range 5-10 mm. The comparisons have shown that the model can adequately predict the histories of temperatures in char particles during combustion in FB. In the first order, the model predicts the influence of the particle size, coal rank (via porosity), and oxygen concentration in its surroundings. 53 refs., 6 figs., 2 tabs.

  20. Quantitative Analysis of Graphene Sheet Content in Wood Char Powders during Catalytic Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    Yan-Jia Liou; Wu-Jang Huang

    2013-01-01

    The quantitative characterization of the graphene sheet content in carbon-containing materials is arguable and has not yet been developed.The authors report on a feasible method to characterize graphene sheet content quantitatively in pyrolized carbon materials using an X-ray diffraction (XRD) spectrometer.A direct carbonation at 300 ℃ followed by catalytic pyrolysis (heat-treatment temperature was set at 700-1400 ℃)under a vacuum condition was used for turning wood waste into pyrolized wood char powders.The graphene content in the samples was calculated through an analysis of full width at half maximum (FWHM) of the carbon (100) crystal plane at around 42°-43° in XRD.Results showed that the FWHM and the calculated graphene sheet content of pyrolized wood char powders depended on the heat-treatment temperature,and the FWHM of wood char powder with well-developed graphene sheets (100%) was determined to be 5.0.In addition,the trend to 100% graphene sheet-contained pyrolized carbon powder was obtained at a heattreatment temperature of 2700 ℃.The resistivity of the wood char powder with 100% graphene sheets was predicted to be 0.01 Ω cm,close to our experimental data of 0.012 and 0.006 Ω cm for commercial graphite and graphene products,respectively.

  1. Synthesis and characterization of resorcinol-formaldehyde resin chars doped by zinc oxide

    Science.gov (United States)

    Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Oranska, Olena I.; Urubkov, Iliya V.; Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga

    2014-06-01

    Polycondensation polymerization of resorcinol-formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol-formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10-40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20-130 nm in diameter and 1-3 μm in length. At a small content of zinc acetate (1 mol per 100-500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

  2. Synthesis and characterization of resorcinol–formaldehyde resin chars doped by zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Gun’ko, Vladimir M., E-mail: vlad_gunko@ukr.net [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Bogatyrov, Viktor M.; Oranska, Olena I. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Urubkov, Iliya V. [Kurdyumov Institute of Metal Physics, 36 Vernadsky Boulevard, 03142 Kyiv (Ukraine); Leboda, Roman; Charmas, Barbara; Skubiszewska-Zięba, Jadwiga [Faculty of Chemistry, Maria Curie-Skłodowska University, 20031 Lublin (Poland)

    2014-06-01

    Polycondensation polymerization of resorcinol–formaldehyde (RF) mixtures in water with addition of different amounts of zinc acetate and then carbonization of dried gels are studied to prepare ZnO doped chars. Zinc acetate as a catalyst of resorcinol–formaldehyde polycondensation affects structural features of the RF resin (RFR) and, therefore, the texture of chars prepared from Zn-doped RFR. The ZnO doped chars are characterized using thermogravimetry, low temperature nitrogen adsorption/desorption, Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM). At a relatively high content of zinc acetate (1 mol per 10–40 mol of resorcinol) in the reaction mixture, the formation of crystallites of ZnO (zincite) occurs in a shape of straight nanorods of 20–130 nm in diameter and 1–3 μm in length. At a small content of zinc acetate (1 mol per 100–500 mol of resorcinol), ZnO in composites is XRD amorphous and does not form individual particles. The ZnO doped chars are pure nanoporous at a minimal ZnO content and nano-mesoporous or nano-meso-macroporous at a higher ZnO content.

  3. Ultrasonic Characterisation of Epoxy Resin/Polyethylene Terephthalate (PET Char Powder Composites

    Directory of Open Access Journals (Sweden)

    Imran ORAL

    2016-11-01

    Full Text Available This study is carried out in order to determine the elastic properties of the Epoxy Resin (ER / Polyethylene terephthalate (PET Char Powder Composites by ultrasonic wave velocity measurement method. Plastic waste was recycled as raw material for the preparation of epoxy composite materials. The supplied chars were mixed with epoxy resin matrix at weight percentages of 10 %, 20 % and 30 % for preparing ER/PET Char Powder (PCP composites. The effect of PET char powder on the elastic properties of ER/PCP composites were investigated by ultrasonic pulse-echo method. According to the obtained results, the composition ratio of 80:20 is the most appropriate composition ratio, which gave the highest elastic constants values for ER/PCP composites. On the other hand, the best electrical conductivity value was obtained for 70:30 composition ratio. It was observed that ultrasonic shear wave velocity correlated more perfectly than any other parameters with hardness.DOI: http://dx.doi.org/10.5755/j01.ms.22.4.12190

  4. EFFECT OF CALCIUM ADDITION ON THE DEFLUORIDATION CAPACITY OF BONE CHAR

    DEFF Research Database (Denmark)

    Jacobsen, P.; Dahi, Elian

    1997-01-01

    Dosage of small amounts of calcium chloride to fluoride water prior to contact with bone char which has already been saturated with fluoride is shown to provide an additional fluoride removal capacity. The additionally obtained removal capacity increases with slower filtration velocities and incr...

  5. Microanalysis of vitrous char and associated polymers: reference and ancient assemblages

    Science.gov (United States)

    Allue, E.; Bonnamy, S.; Courty, M. M.; Gispert I Guirado, F.

    2012-12-01

    Formation of vitrous char that occur in ancient charcoal assemblages have remained unsolved. Laboratory experiments refuted vitrification to resulting from high temperature charring of green or resinous wood. This puzzling problem has been refreshed by showing the association to the charcoal and vitrous char of plastics that were originally supposed to only be produced by petroleum industry. Extraction of similar polymers within geological glassy products from cosmic airbursts has suggested impact processes to possibly forming the carbonaceous polymorphs. The pulverisation at the ground in the Angles village (French Eastern Pyrenees) following the 2011 August 2nd high altitude meteor explosion of exotic debris with vitrous char and polymers, just alike the puzzling ones of the geological and archaeological records, has provided potential reference materials. We present here their microanalysis by Environmental SEM with EDS, Raman micro-spectrometry and FTIR, XRD, TEM, ICP-MS and isotope analyses. The characterization helps elucidating how the carbonaceous polymorphs formed by transient heating and transient high pressure of atmospheric aerosols. Under TEM the vesicular, dense, vitrous char show high structural organization with a dense pattern of nano-sized graphitized domains, metals and mineral inclusions. The coupled Raman-ESEM has allowed identifying a complex pattern at micro scales of ordered "D" peak at 1320-1350 cm-1 and the graphitic, ordered peak at 1576-1590 cm-1, in association to amorphous and poorly graphitic ordered carbon. The later occurs within plant cells that have been extracted from the dense vitrous char by performing controlled combustion under nitrogen up to 1000°C. In contrast, the brittle, vesicular vitrous char and the polymers encountered at the rear of the pulverised airburst debris reveal to be formed of agglutinated micro spherules of amorphous carbon with rare crystallized carbon nano-domains and scattered mineral inclusions. They

  6. Feeding habits of the alien brook trout Salvelinus fontinalis and the native brown trout Salmo trutta in Czech mountain streams

    Directory of Open Access Journals (Sweden)

    Horká Petra

    2017-01-01

    Full Text Available Quantifying patterns of prey resource use is fundamental to identify mechanisms enabling the coexistence of related fish species. Trophic interactions between the native brown trout, Salmo trutta, and the introduced brook trout, Salvelinus fontinalis, were studied monthly from May to October in three mountain streams in Central Europe (Czech Republic. To evaluate whether the feeding habits differ between separated and coexisting populations of these species, one locality where both species coexist, and two allopatric populations of either species were studied. Across the study period, the mean stomach fullness of fish varied, being highest in spring and declining through autumn. The diet overlap (Schoener's overlap index between the species increased through the studied season (from 54.5% in July to 81.5% in October. In allopatry, both species had nearly the same feeding habits. However, in sympatry, brook trout consumed higher proportion of terrestrial invertebrates, while brown trout showed no changes either in the proportions of aquatic and terrestrial prey utilized or in the selectivity for prey categories in comparison to allopatric conditions. The dietary shift observed for brook trout, but not for brown trout, suggests that brown trout is a stronger competitor in the studied sympatric locality, leading the brook trout to change its feeding habits to reduce interspecific competition.

  7. Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

    Science.gov (United States)

    Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge

    2013-01-01

    Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

  8. New insight into the spawning behavior of lake trout, Salvelinus namaycush, from a recovering population in the Laurentian Great Lakes

    Science.gov (United States)

    Binder, Thomas R.; Thompson, Henry T.; Muir, Andrew M.; Riley, Stephen C.; Marsden, J. Ellen; Bronte, Charles R.; Krueger, Charles C.

    2015-01-01

    Spawning behavior of lake trout, Salvelinus namaycush, is poorly understood, relative to stream-dwelling salmonines. Underwater video records of spawning in a recovering population from the Drummond Island Refuge (Lake Huron) represent the first reported direct observations of lake trout spawning in the Laurentian Great Lakes. These observations provide new insight into lake trout spawning behavior and expand the current conceptual model. Lake trout spawning consisted of at least four distinct behaviors: hovering, traveling, sinking, and gamete release. Hovering is a new courtship behavior that has not been previously described. The apparent concentration of hovering near the margin of the spawning grounds suggests that courtship and mate selection might be isolated from the spawning act (i.e., traveling, sinking, and gamete release). Moreover, we interpret jockeying for position displayed by males during traveling as a unique form of male-male competition that likely evolved in concert with the switch from redd-building to itinerant spawning in lake trout. Unlike previous models, which suggested that intra-sexual competition and mate selection do not occur in lake trout, our model includes both and is therefore consistent with evolutionary theory, given that the sex ratio on spawning grounds is skewed heavily towards males. The model presented in this paper is intended as a working hypothesis, and further revision may become necessary as we gain a more complete understanding of lake trout spawning behavior.

  9. Life history differences between fat and lean morphs of lake charr (Salvelinus namaycush) in Great Slave Lake, Northwest Territories, Canada

    Science.gov (United States)

    Hansen, Michael J.; Nate, Nancy A.; Chavarie, Louise; Muir, Andrew M.; Zimmerman, Mara S.; Krueger, Charles C.

    2016-01-01

    Life history characteristics (size, age, plumpness, buoyancy, survival, growth, and maturity) were compared between fat and lean morphs of lake charr Salvelinus namaycush in Great Slave Lake, Canada, to determine if differences may reflect effects of resource polymorphism. Lake charr were sampled using graded-mesh gill nets set in three depth strata. Of 236 lake charr captured, 122 were a fat morph and 114 were a lean morph. Males and females did not differ from each other in any attributes for either fat or lean morphs. The fat morph averaged 15 mm longer, 481 g heavier, and 4.7 years older than the lean morph. The fat morph averaged 26% heavier and 48% more buoyant at length than the lean morph. Survival of the fat morph was 1.7% higher than that of the lean morph. The fat morph grew at a slower annual rate to a shorter asymptotic length than the lean morph. Fat and lean morphs matured at similar lengths and ages. We concluded that the connection between resource polymorphism and life histories in lean versus fat lake charr suggests that morph-specific restoration objectives may be needed in lakes where lake charr diversity is considered to be a restoration goal.

  10. The effect of chars and their water extractable organic carbon (WEOC) fractions on atrazine adsorption-desorption processes

    Science.gov (United States)

    Cavoski, I.; Jablonowski, N.; Burauel, P.; Miano, T.

    2012-04-01

    Chars are carbonaceous material produced from different type of biomass by pyrolysis. They are known as highly effective adsorbents for atrazine therefore limiting its degradation and its diffusion into the aqueous phase. The aim of the present work is to study the effects of different chars and char's derived WEOC on atrazine sorption-desorption processes. The five chars been used in this study derived from: 1) fast pyrolysis from hard wood (FP1); 2) flash pyrolysis from soft wood (FP2); 3) slow pyrolysis from deciduous wood (CC); 4) gasification from deciduous wood (GC) and 5) the market, purchased as activated charcoal standard (AC). Short-term batch equilibration tests were conducted to assess the sorption-desorption behavior of 14C-labeled atrazine on the chars, with a special focus on the desorption behavior using successive dilution method with six consecutive desorption step. Chars and their WEOC were physically and chemically characterized. Results demonstrate that biomass and pyrolysis process used to produce chars affect their physical and chemical properties, and atrazine adsorption-desorption behavior. Atrazine desorption resulted from the positive and competitive interactions between WEOC and chars surfaces. WEOC pool play important role in atrazine adsorption-desorption behavior. FP1 and FP2 with higher concentration of WEOC showed higher desorption rates, whereas GC, CC and AC with insignificant WEOC concentration strongly adsorb atrazine with low desorption rates. According to our results, when high WEOC pools chars are concerned, an increase in atrazine desorption can be observed but further studies would help in confirming the present results.

  11. Influence of molecular structure and adsorbent properties on sorption of organic compounds to a temperature series of wood chars.

    Science.gov (United States)

    Lattao, Charisma; Cao, Xiaoyan; Mao, Jingdong; Schmidt-Rohr, Klaus; Pignatello, Joseph J

    2014-05-01

    Chars from wildfires and soil amendments (biochars) are strong adsorbents that can impact the fate of organic compounds in soil, yet the effects of solute and adsorbent properties on sorption are poorly understood. We studied sorption of benzene, naphthalene, and 1,4-dinitrobenzene from water to a series of wood chars made anaerobically at different heat treatment temperatures (HTT) from 300 to 700 °C, and to graphite as a nonporous, unfunctionalized reference adsorbent. Peak suppression in the NMR spectrum by sorption of the paramagnetic relaxation probe TEMPO indicated that only a small fraction of char C atoms lie near sorption sites. Sorption intensity for all solutes maximized with the 500 °C char, but failed to trend regularly with N2 or CO2 surface area, micropore volume, mesopore volume, H/C ratio, O/C ratio, aromatic fused ring size, or HTT. A model relating sorption intensity to a weighted sum of microporosity and mesoporosity was more successful. Sorption isotherm linearity declined progressively with carbonization of the char. Application of a thermodynamic model incorporating solvent-water and char-graphite partition coefficients permitted for the first time quantification of steric (size exclusion in pores) and π-π electron donor-acceptor (EDA) free energy contributions, relative to benzene. Steric hindrance for naphthalene increases exponentially from 9 to 16 kJ/mol (∼ 1.6-2.9 log units of sorption coefficient) with the fraction of porosity in small micropores. π-π EDA interactions of dinitrobenzene contribute -17 to -19 kJ/mol (3-3.4 log units of sorption coefficient) to sorption on graphite, but less on chars. π-π EDA interaction of naphthalene on graphite is small (-2 to 2 kJ/mol). The results show that sorption is a complex function of char properties and solute molecular structure, and not very predictable on the basis of readily determined char properties.

  12. CHAR CRYSTALLINE TRANSFORMATIONS DURING COAL COMBUSTION AND THEIR IMPLICATIONS FOR CARBON BURNOUT

    Energy Technology Data Exchange (ETDEWEB)

    ROBERT H. HURT

    1998-09-08

    Recent work at Sandia National Laboratories, Imperial College, and the U.K. utility PowerGen, has identified an important mechanism believed to have a large influence on unburned carbon levels from pulverized coal-fired boilers. That mechanism is char carbon crystalline rearrangements on subsecond times scales at temperatures of 1800 - 2500 K, which lead to char deactivation in the flame zones of furnaces. The so-called thermal annealing of carbons is a well known phenomenon, but its key role in carbon burnout has only recently been appreciated, and there is a lack of quantitative data in this time/temperature range. In addition, a new fundamental tool has recently become available to study crystalline transformations, namely high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars. Motivated by these new developments, this University Coal Research project has been initiated with the following two goals:  to determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history.  to characterize the effect of this thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis. Work is currently underway on the following three tasks: Task 1 Experimental technique development. The goal of this task is to develop and demonstrate an apparatus and procedure for measuring transient, high-temperature, thermal deactivation of coal chars. While peak gas temperatures in boilers are often in the range 1800 - 2000 K, peak particle temperatures can be much higher due to high rates of heat release at the particle surface due to exothermic carbon oxidation. The prototype transient heat treatment apparatus is based on an inert-gas purged graphite-rod sample holder that is subjected to rapid Joule heating to

  13. Effect of torrefaction on the properties of rice straw high temperature pyrolysis char: Pore structure, aromaticity and gasification activity.

    Science.gov (United States)

    Chen, Handing; Chen, Xueli; Qin, Yueqiang; Wei, Juntao; Liu, Haifeng

    2017-03-01

    The influence of torrefaction on the physicochemical characteristics of char during raw and water washed rice straw pyrolysis at 800-1200°C is investigated. Pore structure, aromaticity and gasification activity of pyrolysis chars are compared between raw and torrefied samples. For raw straw, BET specific surface area decreases with the increased torrefaction temperature at the same pyrolysis temperature and it approximately increases linearly with weight loss during pyrolysis. The different pore structure evolutions relate to the different volatile matters and pore structures between raw and torrefied straw. Torrefaction at higher temperature would bring about a lower graphitization degree of char during pyrolysis of raw straw. Pore structure and carbon crystalline structure evolutions of raw and torrefied water washed straw are different from these of raw straw during pyrolysis. For both raw and water washed straw, CO2 gasification activities of pyrolysis chars are different between raw and torrefied samples.

  14. Nitric oxide reduction over biomass and coal chars under fluidized bed combustion conditions: the role of thermal annealing

    Energy Technology Data Exchange (ETDEWEB)

    Piero Salatino; Anna Di Somma; Roberto Solimene; Riccardo Chirone [Universita degli Studi di Napoli Federico II, Napoli (Italy). Dipartimento di Ingegneria Chimica

    2008-07-01

    The de-NOx potential of biomass-and waste-derived fuels candidate for cofiring with coal is assessed. The experimental procedure is based on operation of a bench scale fluidized bed reactor where NO-doped nitrogen is contacted with batches of the fuel. A second type of experiment has been purposely designed to assess the extent of thermodeactivation of biogenous fuels, i.e. the loss of reactivity toward the NOx-char reaction as char is annealed for pre-set times at temperatures typical of fluidized bed combustion. A simple phenomenological model is developed to shed light on the basic features of the interaction between heterogeneous char-NOx reaction and thermal annealing of the char. Results are discussed in the light of the potential exploitation of synergistic effects on NOx emission associated with cofiring with coal. 21 refs., 8 figs., 1 tab.

  15. Upgrading the rice husk char obtained by flash pyrolysis for the production of amorphous silica and high quality activated carbon.

    Science.gov (United States)

    Alvarez, Jon; Lopez, Gartzen; Amutio, Maider; Bilbao, Javier; Olazar, Martin

    2014-10-01

    The overall valorization of rice husk char obtained by flash pyrolysis in a conical spouted bed reactor (CSBR) has been studied in a two-step process. Thus, silica has been recovered in a first step and the remaining carbon material has been subjected to steam activation. The char samples used in this study have been obtained by continuous flash pyrolysis in a conical spouted bed reactor at 500°C. Extraction with Na2CO3 allows recovering 88% of the silica contained in the rice husk char. Activation of the silica-free rice husk char has been carried out in a fixed bed reactor at 800°C using steam as activating agent. The porous structure of the activated carbons produced includes a combination of micropores and mesopores, with a BET surface area of up to 1365m(2)g(-1) at the end of 15min.

  16. Morphological changes during oxidation of a single char particle. Quarterly progress report, April 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    d`Amore, M. [Salerno Univ. (Italy). Dept. of Chemical and Food Engineering; Tognotti, L. [Pisa Univ. (Italy). Dept. of Chemical Engineering; Sarofim, A.F. [Massachusetts Inst. of Tech., Cambridge, MA (United States). Dept. of Chemical Engineering

    1992-12-31

    In this study, the changes with conversion in morphology of a carbon char in the temperature range 500--1200 K are followed by using an electrodynamic balance (EDB) (Spjut et al., 1985; Dudek, 1988; Bar-ziv et al., 1989). This device allows one to measure in situ, over temperature range wider than in other apparatuses, mass, diameter, density, surface area, rate of reaction and temperature for a single, suspended submillimeter particle. By following with the EDB the changes in the char as it reacts, it is possible to study the influence of the porous texture on the reaction behavior and shed some light on the contribution by micropores to the reaction in the chemical kinetic controlled regime.

  17. Synthesis and Application of a Novel Polyamide Charring Agent for Halogen-Free Flame Retardant Polypropylene

    Directory of Open Access Journals (Sweden)

    Jie Liu

    2013-01-01

    Full Text Available A novel charring agent, poly(p-ethylene terephthalamide (PETA, for halogen-free flame retardant polypropylene was synthesized by using p-phthaloyl chloride (TPC and ethylenediamine through solution polycondensation at low temperature, and the effects of PETA on flame retardance of polypropylene (PP/IFR systems were studied. The experimental results showed that PETA could considerably enhance the fire retardant performance as proved by evidence of the increase of limiting oxygen index (LOI values, the results of UL-94 tests, and cone calorimeter tests (CCT. Fourier transform infrared spectroscopy (FTIR and scanning electron microscope (SEM demonstrated that an appropriate amount of PETA could react with PP/IFR system to form cross-link network; a more compact char layer could be formed which was responsible for the improved thermal and flame retardant properties of PP/IFR systems. However, the superfluous amount of PETA would play the negative role.

  18. Hydrogen Production From Crude Bio-oil and Biomass Char by Electrochemical Catalytic Reforming

    Institute of Scientific and Technical Information of China (English)

    Xing-long Li; Shen Ning; Li-xia Yuan; Quan-xin Li

    2011-01-01

    We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method.The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass.The product gas was a mixed gas containing 72%H2,26%CO2,1.9%CO,and a trace amount of CH4.It was observed that adding biomass char (a by-product of pyrolysis of biomass) could remarkably increase the absolute H2 yield (about 20%-50%).The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H2O.In addition,the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

  19. Production of Low-Phosphorus Molten Iron from High-Phosphorus Oolitic Hematite Using Biomass Char

    Science.gov (United States)

    Tang, Huiqing; Qi, Tengfei; Qin, Yanqi

    2015-09-01

    In this study, an energy-saving and environmentally friendly method to produce low-phosphorus molten iron from high-phosphorus oolitic hematite was experimentally investigated and theoretically analyzed. The results indicate that biomass char is a suitable reducing agent for the proposed method. In the direct reduction stage, the ore-char briquette reached a metallization degree of 80-82% and a residual carbon content of 0.1-0.3 mass%. Under the optimized condition, phosphorus remained in the gangue as calcium phosphate. In the melting separation stage, phosphorus content ([%P]) in molten iron could be controlled by introducing a Na2CO3 additive, and the phosphorus behavior could be predicted using ion molecular coexistence theory. Molten iron with [%P] less than 0.3 mass% was obtained from the metallic briquettes with the aforementioned quality by introducing 2-4% Na2CO3 and the iron recovery rate was 75-78%.

  20. Hydrogen Production From Crude Bio-oil and Biomass Char by Electrochemical Catalytic Reforming

    Science.gov (United States)

    Li, Xing-long; Ning, Shen; Yuan, Li-xia; Li, Quan-xin

    2011-08-01

    We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method. The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass. The product gas was a mixed gas containing 72%H2, 26%CO2, 1.9%CO, and a trace amount of CH4. It was observed that adding biomass char (a by-product of pyrolysis of biomass) could remarkably increase the absolute H2 yield (about 20%-50%). The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H2O. In addition, the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

  1. Time resolved quantitative imaging of charring in materials at temperatures above 1000 K

    Science.gov (United States)

    Böhrk, Hannah; Jemmali, Raouf

    2016-07-01

    A device is presented allowing for in situ investigation of chemically changing materials by means of X-ray imaging. A representative cork ablator sample, additionally instrumented with thermocouples, is encapsulated in an evacuated cell heating a sample surface with a heat flux of 230 kW/m2. The images show the sample surface and the in-depth progression of the char front dividing the char layer from the virgin material. Correlating the images to thermocouple data allows for the deduction of a reaction temperature. For the representative cork ablator investigated at the present conditions, the progression rate of the pyrolysis layer is determined to 0.0285 mm/s and pyrolysis temperature is 770 or 737 K, depending on the pre-existing conditions. It is found that the novel device is ideally suited for volume process imaging.

  2. Characterization of adsorption of aqueous arsenite and arsenate onto charred dolomite in microcolumn systems.

    Science.gov (United States)

    Salameh, Yousef; Al-Muhtaseb, Ala'a H; Mousa, Hasan; Walker, Gavin M; Ahmad, Mohammad N M

    2014-01-01

    In this work, the removal of arsenite, As(III), and arsenate, As(V), from aqueous solutions onto thermally processed dolomite (charred dolomite) via microcolumn was evaluated. The effects of mass of adsorbent (0.5-2 g), initial arsenic concentration (50-2000 ppb) and particle size (dolomite in a microcolumn were investigated. It was found that the adsorption of As(V) and As(III) onto charred dolomite exhibited a characteristic 'S' shape. The adsorption capacity increased as the initial arsenic concentration increased. A slow decrease in the column adsorption capacity was noted as the particle size increased from>0.335 to 0.710-2.00 mm. For the binary system, the experimental data show that the adsorption of As(V) and As(III) was independent of both ions in solution. The experimental data obtained from the adsorption process were successfully correlated with the Thomas Model and Bed Depth Service Time Model.

  3. Effects of catalytic mineral matter on CO/CO sub 2 ratio, temperature and burning time for char combustion

    Energy Technology Data Exchange (ETDEWEB)

    Longwell, J.P.; Sarofim, A.F.; Lee, Chun-Hyuk.

    1990-01-01

    In this program we are measuring the CO{sub 2}/CO ratio for both catalyzed and uncatalyzed chars over a wide range of temperature. These results will then be used to develop predictive models for char temperature and burning rates. In this report progress on modeling particle temperature under conditions where ignition occurs is reported. A comparison of preliminary modeling results with experimental results is also reported. 11 refs., 4 figs.

  4. Modeling of single char combustion, including CO oxidation in its boundary layer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C.H.; Longwell, J.P.; Sarofim, A.F.

    1994-10-25

    The combustion of a char particle can be divided into a transient phase where its temperature increases as it is heated by oxidation, and heat transfer from the surrounding gas to an approximately constant temperature stage where gas phase reaction is important and which consumes most of the carbon and an extinction stage caused by carbon burnout. In this work, separate models were developed for the transient heating where gas phase reactions were unimportant and for the steady temperature stage where gas phase reactions were treated in detail. The transient char combustion model incorporates intrinsic char surface production of CO and CO{sub 2}, internal pore diffusion and external mass and heat transfer. The model provides useful information for particle ignition, burning temperature profile, combustion time, and carbon consumption rate. A gas phase reaction model incorporating the full set of 28 elementary C/H/O reactions was developed. This model calculated the gas phase CO oxidation reaction in the boundary layer at particle temperatures of 1250 K and 2500 K by using the carbon consumption rate and the burning temperature at the pseudo-steady state calculated from the temperature profile model but the transient heating was not included. This gas phase model can predict the gas species, and the temperature distributions in the boundary layer, the CO{sub 2}/CO ratio, and the location of CO oxidation. A mechanistic heat and mass transfer model was added to the temperature profile model to predict combustion behavior in a fluidized bed. These models were applied to data from the fluidized combustion of Newlands coal char particles. 52 refs., 60 figs.

  5. Structural analysis of char by Raman spectroscopy: Improving band assignments through computational calculations from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Matthew W.; Dallmeyer, Ian; Johnson, Timothy J.; Brauer, Carolyn S.; McEwen, Jean-Sabin; Espinal, Juan F.; Garcia-Perez, Manuel

    2016-04-01

    Raman spectroscopy is a powerful tool for the characterization of many carbon 27 species. The complex heterogeneous nature of chars and activated carbons has confounded 28 complete analysis due to the additional shoulders observed on the D-band and high intensity 29 valley between the D and G-bands. In this paper the effects of various vacancy and substitution 30 defects have been systematically analyzed via molecular modeling using density functional 31 theory (DFT) and how this is manifested in the calculated gas-phase Raman spectra. The 32 accuracy of these calculations was validated by comparison with (solid-phase) experimental 33 spectra, with a small correction factor being applied to improve the accuracy of frequency 34 predictions. The spectroscopic effects on the char species are best understood in terms of a 35 reduced symmetry as compared to a “parent” coronene molecule. Based upon the simulation 36 results, the shoulder observed in chars near 1200 cm-1 has been assigned to the totally symmetric 37 A1g vibrations of various small polyaromatic hydrocarbons (PAH) as well as those containing 38 rings of seven or more carbons. Intensity between 1400 cm-1 and 1450 cm-1 is assigned to A1g 39 type vibrations present in small PAHs and especially those containing cyclopentane rings. 40 Finally, band intensity between 1500 cm-1 and 1550 cm-1 is ascribed to predominately E2g 41 vibrational modes in strained PAH systems. A total of ten potential bands have been assigned 42 between 1000 cm-1 and 1800 cm-1. These fitting parameters have been used to deconvolute a 43 thermoseries of cellulose chars produced by pyrolysis at 300-700 °C. The results of the 44 deconvolution show consistent growth of PAH clusters with temperature, development of non-45 benzyl rings as temperature increases and loss of oxygenated features between 400 °C and 46 600 °C

  6. Fixed-bed adsorption study of methylene blue onto pyrolytic tire char

    Science.gov (United States)

    Makrigianni, Vassiliki; Giannakas, Aris; Papadaki, Maria; Albanis, Triantafyllos; Konstantinou, Ioannis

    2016-04-01

    In this work, the adsorption efficiency of acid treated pyrolytic tire char to cationic methylene blue (MB) dye adsorption from aqueous solutions was investigated by fixed-bed adsorption column experiments. The effects of the initial dye concentration (10 - 40 mg L-1) and feed flow rate (50 - 150 mL min -1) with a fixed bed height (15 cm) were studied in order to determine the breakthrough characteristics of the adsorption system. The Adams-Bohart, Yoon-Nelson and Thomas model were applied to the adsorption of MB onto char at different operational conditions to predict the breakthrough curves and to determine the characteristic parameters of the column. The results showed that the maximum adsorbed quantities decreased with increasing flow rate and increased with increasing initial MB concentration. Breakthrough time and exhaustion time increased with decreasing inlet dye concentration and flow rate. In contrast with Adams-Bohart model, Yoon-Nelson model followed by Thomas model were found more suitable to describe the fixed-bed adsorption of methylene blue by char. The correlation coefficient values R2 for both models at different operating conditions are higher than 0.9 and the low average relative error values provided very good fittings of experimental data at different operating conditions. Higher adsorption capacity of 3.85 mg g -1 was obtained at 15 cm of adsorbent bed height, flow rate of 100 mL min -1and initial MB concentration of 40 mg L-1. Although that activated carbons exhibited higher adsorption capacities in the literature, acid-treated pyrolytic tire char was found to be considerably efficient adsorbent for the removal of MB dye column taking into account the advantages of the simpler production process compared to activated carbons, as well as, the availability of waste tire feedstock and concurrent waste tire management.

  7. Bone char surface modification by nano-gold coating for elemental mercury vapor removal

    Energy Technology Data Exchange (ETDEWEB)

    Assari, Mohamad javad [Department of Environmental & Occupational Health, Faculty of Medical Sciences, Tarbiat Modares university, Tehran (Iran, Islamic Republic of); Rezaee, Abbas, E-mail: rezaee@modares.ac.ir [Department of Environmental & Occupational Health, Faculty of Medical Sciences, Tarbiat Modares university, Tehran (Iran, Islamic Republic of); Rangkooy, Hossinali [Occupational Health Department, Faculty of Health, Jondishapor Medical Sciences University, Ahvaz (Iran, Islamic Republic of)

    2015-07-01

    Highlights: • A novel nanocomposite including bone char and gold nanoparticle was developed for capture of Hg{sup 0} vapor. • EDS and XRD results confirm the presence of nano-gold on the surface of the bone char support. • The majority of the pores were found to be in the mesoporous range. • The dynamic capacity of 586 μg/g was obtained for Hg{sup 0} vapor. - Abstract: The present work was done to develop a novel nanocomposite using bone char coated with nano-gold for capture of elemental mercury (Hg{sup 0}) from air. The morphologies, structures, and chemical constitute of the prepared nanocomposite were evaluated by UV–VIS–NIR, dynamic light-scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infra-red (FTIR) spectroscopy, and energy dispersive X-ray spectroscopy (EDS). The capture performance of nanocomposite was evaluated in a needle trap for mercury vapor. An on-line setup based on cold vapor atomic absorption spectrometry (CVAAS) was designed for Hg{sup 0} determination. Dynamic capacity of nanocomposite for Hg{sup 0} was shown high efficient operating capacity of 586.7 μg/g. As temperature increases, the dynamic adsorption capacity of the nanocomposite was decreased, which are characteristics of physicosorption processes. It was found that the surface modification of bone char with nano-gold has various advantages such as high operating dynamic adsorption capacity and low cost preparation. It was also demonstrated that the developed nanocomposite is suitable for on-line monitoring of Hg{sup 0}. It could be applied for the laboratory and field studies.

  8. Mixed Waste Treatment Using the ChemChar Thermolytic Detoxification Technique

    Energy Technology Data Exchange (ETDEWEB)

    Kuchynka, D.J.

    1997-01-01

    This R and D program addresses the treatment of mixed waste employing the ChemChar Thermolytic Detoxification process. Surrogate mixed waste streams will be treated in a four inch diameter, continuous feed, adiabatic reactor with the goal of meeting all regulatory treatment levels for the contaminants in the surrogates with the concomitant production of contaminant free by-products. Successful completion of this program will show that organic contaminants in mixed waste surrogates will be converted to a clean, energy rich synthesis gas capable of being used, without further processing, for power or heat generation. The inorganic components in the surrogates will be found to be adsorbed on a macroporous coal char activated carbon substrate which is mixed with the waste prior to treatment. These contaminants include radioactive metal surrogate species, RCRA hazardous metals and any acid gases formed during the treatment process. The program has three main tasks that will be performed to meet the above objectives. The first task is the design and construction of the four inch reactor at Mirage Systems in Sunnyvale, CA. The second task is production and procurement of the activated carbon char employed in the ChemChartest runs and identification of two surrogate mixed wastes. The last task is testing and operation of the reactor on char/surrogate waste mixtures to be performed at the University of Missouri. The deliverables for the project are a Design Review Report, Operational Test Plan, Topical Report and Final Report. This report contains only the results of the design and construction carbon production-surrogate waste identification tasks.Treatment of the surrogate mixed wastes has just begun and will not be reported in this version of the Final Report. The latter will be reported in the final version of the Final Report.

  9. Determination of reactivity parameters of model carbons, cokes and flame-chars

    DEFF Research Database (Denmark)

    Sørensen, Lasse Holst; Gjernes, Erik; Jessen, Thomas

    1996-01-01

    Reactivity profiles are defined and measured with thermogravimetry for a dense metallurgical Longyear coke, a polymer-derived porous active carbon, Carboxen 1000, and three flame-chars, Illinois #6, Pittsburgh #8 and New Mexico Blue #1. For each sample it is found that the reactivity profile can ...... reactivity measure is used to rank fuels with very different structural profiles, at varying levels of burnout, temperature and oxygen partial pressure. Keyword: TGA,Reactivity,Coal...

  10. Intraspecific variation in thermal tolerance and acclimation capacity in brook trout (Salvelinus fontinalis): physiological implications for climate change.

    Science.gov (United States)

    Stitt, Bradley C; Burness, Gary; Burgomaster, Kirsten A; Currie, Suzanne; McDermid, Jenni L; Wilson, Chris C

    2014-01-01

    Cold-water fishes are becoming increasingly vulnerable as changing thermal conditions threaten their future sustainability. Thermal stress and habitat loss from increasing water temperatures are expected to impact population viability, particularly for inland populations with limited adaptive resources. Although the long-term persistence of cold-adapted species will depend on their ability to cope with and adapt to changing thermal conditions, very little is known about the scope and variation of thermal tolerance within and among conspecific populations and evolutionary lineages. We studied the upper thermal tolerance and capacity for acclimation in three captive populations of brook trout (Salvelinus fontinalis) from different ancestral thermal environments. Populations differed in their upper thermal tolerance and capacity for acclimation, consistent with their ancestry: the northernmost strain (Lake Nipigon) had the lowest thermal tolerance, while the strain with the most southern ancestry (Hill's Lake) had the highest thermal tolerance. Standard metabolic rate increased following acclimation to warm temperatures, but the response to acclimation varied among strains, suggesting that climatic warming may have differential effects across populations. Swimming performance varied among strains and among acclimation temperatures, but strains responded in a similar way to temperature acclimation. To explore potential physiological mechanisms underlying intraspecific differences in thermal tolerance, we quantified inducible and constitutive heat shock proteins (HSP70 and HSC70, respectively). HSPs were associated with variation in thermal tolerance among strains and acclimation temperatures; HSP70 in cardiac and white muscle tissues exhibited similar patterns, whereas expression in hepatic tissue varied among acclimation temperatures but not strains. Taken together, these results suggest that populations of brook trout will vary in their ability to cope with a

  11. Evolution and origin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in Canada's Great Bear Lake.

    Science.gov (United States)

    Harris, L N; Chavarie, L; Bajno, R; Howland, K L; Wiley, S H; Tonn, W M; Taylor, E B

    2015-01-01

    Range expansion in north-temperate fishes subsequent to the retreat of the Wisconsinan glaciers has resulted in the rapid colonization of previously unexploited, heterogeneous habitats and, in many situations, secondary contact among conspecific lineages that were once previously isolated. Such ecological opportunity coupled with reduced competition likely promoted morphological and genetic differentiation within and among post-glacial fish populations. Discrete morphological forms existing in sympatry, for example, have now been described in many species, yet few studies have directly assessed the association between morphological and genetic variation. Morphotypes of Lake Trout, Salvelinus namaycush, are found in several large-lake systems including Great Bear Lake (GBL), Northwest Territories, Canada, where several shallow-water forms are known. Here, we assess microsatellite and mitochondrial DNA variation among four morphotypes of Lake Trout from the five distinct arms of GBL, and also from locations outside of this system to evaluate several hypotheses concerning the evolution of morphological variation in this species. Our data indicate that morphotypes of Lake Trout from GBL are genetically differentiated from one another, yet the morphotypes are still genetically more similar to one another compared with populations from outside of this system. Furthermore, our data suggest that Lake Trout colonized GBL following dispersal from a single glacial refugium (the Mississippian) and support an intra-lake model of divergence. Overall, our study provides insights into the origins of morphological and genetic variation in post-glacial populations of fishes and provides benchmarks important for monitoring Lake Trout biodiversity in a region thought to be disproportionately susceptible to impacts from climate change.

  12. Fine-scale population structure and riverscape genetics of brook trout (Salvelinus fontinalis) distributed continuously along headwater channel networks

    Science.gov (United States)

    Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.

    2011-01-01

    Linear and heterogeneous habitat makes headwater stream networks an ideal ecosystem in which to test the influence of environmental factors on spatial genetic patterns of obligatory aquatic species. We investigated fine-scale population structure and influence of stream habitat on individual-level genetic differentiation in brook trout (Salvelinus fontinalis) by genotyping eight microsatellite loci in 740 individuals in two headwater channel networks (7.7 and 4.4 km) in Connecticut, USA. A weak but statistically significant isolation-by-distance pattern was common in both sites. In the field, many tagged individuals were recaptured in the same 50-m reaches within a single field season (summer to fall). One study site was characterized with a hierarchical population structure, where seasonal barriers (natural falls of 1.5–2.5 m in height during summer base-flow condition) greatly reduced gene flow and perceptible spatial patterns emerged because of the presence of tributaries, each with a group of genetically distinguishable individuals. Genetic differentiation increased when pairs of individuals were separated by high stream gradient (steep channel slope) or warm stream temperature in this site, although the evidence of their influence was equivocal. In a second site, evidence for genetic clusters was weak at best, but genetic differentiation between individuals was positively correlated with number of tributary confluences. We concluded that the population-level movement of brook trout was limited in the study headwater stream networks, resulting in the fine-scale population structure (genetic clusters and clines) even at distances of a few kilometres, and gene flow was mitigated by ‘riverscape’ variables, particularly by physical barriers, waterway distance (i.e. isolation-by-distance) and the presence of tributaries.

  13. Estimates of lake trout (Salvelinus namaycush) diet in Lake Ontario using two and three isotope mixing models

    Science.gov (United States)

    Colborne, Scott F.; Rush, Scott A.; Paterson, Gordon; Johnson, Timothy B.; Lantry, Brian F.; Fisk, Aaron T.

    2016-01-01

    Recent development of multi-dimensional stable isotope models for estimating both foraging patterns and niches have presented the analytical tools to further assess the food webs of freshwater populations. One approach to refine predictions from these analyses is to include a third isotope to the more common two-isotope carbon and nitrogen mixing models to increase the power to resolve different prey sources. We compared predictions made with two-isotope carbon and nitrogen mixing models and three-isotope models that also included sulphur (δ34S) for the diets of Lake Ontario lake trout (Salvelinus namaycush). We determined the isotopic compositions of lake trout and potential prey fishes sampled from Lake Ontario and then used quantitative estimates of resource use generated by two- and three-isotope Bayesian mixing models (SIAR) to infer feeding patterns of lake trout. Both two- and three-isotope models indicated that alewife (Alosa pseudoharengus) and round goby (Neogobius melanostomus) were the primary prey items, but the three-isotope models were more consistent with recent measures of prey fish abundances and lake trout diets. The lake trout sampled directly from the hatcheries had isotopic compositions derived from the hatchery food which were distinctively different from those derived from the natural prey sources. Those hatchery signals were retained for months after release, raising the possibility to distinguish hatchery-reared yearlings and similarly sized naturally reproduced lake trout based on isotopic compositions. Addition of a third-isotope resulted in mixing model results that confirmed round goby have become an important component of lake trout diet and may be overtaking alewife as a prey resource.

  14. Sibship reconstruction for inferring mating systems, dispersal and effective population size in headwater brook trout (Salvelinus fontinalis) populations

    Science.gov (United States)

    Kanno, Yoichiro; Vokoun, Jason C.; Letcher, Benjamin H.

    2011-01-01

    Brook trout Salvelinus fontinalis populations have declined in much of the native range in eastern North America and populations are typically relegated to small headwater streams in Connecticut, USA. We used sibship reconstruction to infer mating systems, dispersal and effective population size of resident (non-anadromous) brook trout in two headwater stream channel networks in Connecticut. Brook trout were captured via backpack electrofishing using spatially continuous sampling in the two headwaters (channel network lengths of 4.4 and 7.7 km). Eight microsatellite loci were genotyped in a total of 740 individuals (80–140 mm) subsampled in a stratified random design from all 50 m-reaches in which trout were captured. Sibship reconstruction indicated that males and females were both mostly polygamous although single pair matings were also inferred. Breeder sex ratio was inferred to be nearly 1:1. Few large-sized fullsib families (>3 individuals) were inferred and the majority of individuals were inferred to have no fullsibs among those fish genotyped (family size = 1). The median stream channel distance between pairs of individuals belonging to the same large-sized fullsib families (>3 individuals) was 100 m (range: 0–1,850 m) and 250 m (range: 0–2,350 m) in the two study sites, indicating limited dispersal at least for the size class of individuals analyzed. Using a sibship assignment method, the effective population size for the two streams was estimated at 91 (95%CI: 67–123) and 210 (95%CI: 172–259), corresponding to the ratio of effective-to-census population size of 0.06 and 0.12, respectively. Both-sex polygamy, low variation in reproductive success, and a balanced sex ratio may help maintain genetic diversity of brook trout populations with small breeder sizes persisting in headwater channel networks.

  15. pH preference and avoidance responses of adult brook trout Salvelinus fontinalis and brown trout Salmo trutta.

    Science.gov (United States)

    Fost, B A; Ferreri, C P

    2015-03-01

    The pH preferred and avoided by wild, adult brook trout Salvelinus fontinalis and brown trout Salmo trutta was examined in a series a laboratory tests using gradual and steep-gradient flow-through aquaria. The results were compared with those published for the observed segregation patterns of juvenile S. fontinalis and S. trutta in Pennsylvania streams. The adult S. trutta tested showed a preference for pH 4·0 while adult S. fontinalis did not prefer any pH within the range tested. Salmo trutta are not found in Pennsylvania streams with a base-flow pH pH well above 4·0. Adult S. trutta displayed a lack of avoidance at pH below 5·0, as also reported earlier for juveniles. The avoidance pH of wild, adult S. fontinalis (between pH 5·5 and 6·0) and S. trutta (between pH 6·5 and 7·0) did not differ appreciably from earlier study results for the avoidance pH of juvenile S. fontinalis and S. trutta. A comparison of c.i. around these avoidance estimates indicates that avoidance pH is similar among adult S. fontinalis and S. trutta in this study. The limited overlap of c.i. for avoidance pH values for the two species, however, suggests that some S. trutta will display avoidance at a higher pH when S. fontinalis will not. The results of this study indicate that segregation patterns of adult S. fontinalis and S. trutta in Pennsylvania streams could be related to pH and that competition with S. trutta could be mediating the occurrence of S. fontinalis at some pH levels.

  16. Temperature Trends in Coal Char Combustion under Oxy-fuel Conditions for the Determination of Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Samira [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hecht, Ethan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2014-08-01

    Oxy-fuel combustion technology with carbon capture and storage could significantly reduce global CO2 emissions, a greenhouse gas. Implementation can be aided by computational fluid dynamics (CFD) simulations, which require an accurate understanding of coal particle kinetics as they go through combustion in a range of environments. To understand the kinetics of pulverized coal char combustion, a heated flow reactor was operated under a wide range of experimental conditions. We varied the environment for combustion by modifying the diluent gas, oxygen concentration, gas flow rate, and temperature of the reactor/reacting gases. Measurements of reacting particle temperatures were made for a sub-bituminous and bituminous coal char, in environments with CO2 or N2 as the diluent gas, with 12, 24, and 36 vol-% oxygen concentration, at 50, 80, 100, and 200 standard liters per minute flowing through the reactor, reactor temperatures of 1200, 1400 K, at pressures slightly above atmospheric. The data shows consistent increasing particle temperature with increased oxygen concentration, reactor temperature and higher particle temperatures for N2 diluent than CO2. We also see the effects of CO2 gasification when different ranks of coal are used, and how the reduction in the temperature due to the CO2 diluent is greater for the coal char that has higher reactivity. Quantitative measurements for temperature are not yet complete due to ongoing calibration of detection systems.

  17. Preparation of Bamboo Chars and Bamboo Activated Carbons to Remove Color and COD from Ink Wastewater.

    Science.gov (United States)

    Hata, Motohide; Amano, Yoshimasa; Thiravetyan, Paitip; Machida, Motoi

    2016-01-01

    Bamboo chars and bamboo activated carbons prepared by steam activation were applied for ink wastewater treatment. Bamboo char at 800 °C was the best for the removal of color and chemical oxygen demand (COD) from ink wastewater compared to bamboo chars at 300 to 700 °C due to higher surface area and mesopore volume. Bamboo activated carbon at 600 °C (S600) was the best compared to bamboo activated carbon at 800 °C (S800), although S800 had larger surface area (1108 m(2)/g) than S600 (734 m(2)/g). S600 had higher mesopore volume (0.20 cm(3)/g) than S800 (0.16 cm(3)/g) and therefore achieved higher color and COD removal. All bamboo activated carbons showed higher color and COD removal efficiency than commercial activated carbon. In addition, S600 had the superior adsorption capacity for methylene blue (0.89 mmol/g). Therefore, bamboo is a suitable material to prepare adsorbents for removal of organic pollutants.

  18. Characterization of red mud-epoxy intumescent char using surface imaging and micro analysis

    Energy Technology Data Exchange (ETDEWEB)

    Arogundade, A. I., E-mail: ajiunolorioba@gmail.com; Megat-Yusoff, P. S. M., E-mail: puteris@petronas.com.my; Faiz, A. [Department of Mechanical Engineering, Universiti Tecknologi Petronas (Malaysia); Bhat, A. H. [Department of Fundamental and Applied Science, Universiti Tecknologi Petronas (Malaysia)

    2015-07-22

    In this study, red mud (RM), an oxide waste was proposed as reinforcing, synergistic filler for the traditional epoxy intumescent coating (IC). 5.5 wt% of acid-modified and unmodified red mud were introduced into the basic intumescent formulation of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). In order to predict effect of modification on its suitability, Field emission electron scanning microscopy and Fourier transform infra red were used to obtain detailed characteristics such as the cell size, pore distribution, homogeneity and chemical composition of the red mud-epoxy carbonaceous char. Both acid-modified and unmodified RM-filled ICs produced chars with smaller and more closely packed cells compared to chars from the unfilled coating. Both coating types had hard carbonaceous metal phosphate coverings that could act as heat barriers. The unmodified red mud was found to be antagonistic to the intumescent action with an expansion of only 2 times the initial thickness. The leached, low iron-red mud produced an expansion of 15 times the initial thickness, but possessed a hollow interior. From these findings, it may be deduced that while acid leaching of red mud may improve intumescent expansion, it would be necessary to optimize the percent filler loading to improve residual mass.

  19. Characterization of red mud-epoxy intumescent char using surface imaging and micro analysis

    Science.gov (United States)

    Arogundade, A. I.; Megat-Yusoff, P. S. M.; Bhat, A. H.; Faiz, A.

    2015-07-01

    In this study, red mud (RM), an oxide waste was proposed as reinforcing, synergistic filler for the traditional epoxy intumescent coating (IC). 5.5 wt% of acid-modified and unmodified red mud were introduced into the basic intumescent formulation of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL). In order to predict effect of modification on its suitability, Field emission electron scanning microscopy and Fourier transform infra red were used to obtain detailed characteristics such as the cell size, pore distribution, homogeneity and chemical composition of the red mud-epoxy carbonaceous char. Both acid-modified and unmodified RM-filled ICs produced chars with smaller and more closely packed cells compared to chars from the unfilled coating. Both coating types had hard carbonaceous metal phosphate coverings that could act as heat barriers. The unmodified red mud was found to be antagonistic to the intumescent action with an expansion of only 2 times the initial thickness. The leached, low iron-red mud produced an expansion of 15 times the initial thickness, but possessed a hollow interior. From these findings, it may be deduced that while acid leaching of red mud may improve intumescent expansion, it would be necessary to optimize the percent filler loading to improve residual mass.

  20. Holocene linkages between char, soot, biomass burning and climate from Lake Daihai, China

    Science.gov (United States)

    Han, Y. M.; Marlon, J. R.; Cao, J. J.; Jin, Z. D.; An, Z. S.

    2012-12-01

    Black or elemental carbon (EC), including soot and char, are byproducts of anthropogenic fossil-fuel and biomass burning, and also of wildfires. EC, and particularly soot, strongly affects atmospheric chemistry and physics and thus radiative forcing; it can also alter regional climate and precipitation. Pre-industrial variations in EC as well as its source areas and controls however, are poorly known. Here we use a lake-sediment EC record from China to reconstruct Holocene variations in soot (combustion emissions formed via gas-to-particle conversion processes) and char (combustion residues from pyrolysis) measured with a thermal/optical method. Comparisons with sedimentary charcoal records (i.e., particles measured microscopically), climate and population data are used to infer variations in biomass burning and its controls. During the Holocene, positive correlations are observed between EC and an independent index of regional biomass burning. Negative correlations are observed between EC and monsoon intensity, and tree cover inferred from arboreal pollen percentages. Abrupt declines in temperature are also linked with widespread declines in fire. Our results 1) confirm the robustness of a relatively new method for reconstructing variations in EC; 2) document variations in regional biomass burning; 3) support a strong climatic control of biomass burning throughout the Holocene; and 4) indicate that char levels are higher today than at any time during the Holocene.

  1. Effects of Bio-char on Soil Microbes in Herbicide Residual Soils

    Directory of Open Access Journals (Sweden)

    WANG Gen-lin

    2015-10-01

    Full Text Available Effects of biological carbon (bio-char on soil microbial community were studied by pot experiments simulating long residual herbicide residues in soil environment, which clarifed the improvement of biochar and its structural properties on soil microenvironment. The results showed that fungi and actinomycetes had the same effect tendency within 0~0.72 mg·kg-1 in clomazone residue which increased the role of stimulation with crop growth process prolonged, especially in high residue treatment, but strong inhibitory effect on bacteria community was occured early which returned to normal until sugar beet growth to fiftieth day. Soil fungi community decreased with bio-char adding, but had no significant difference with the control. When clomazone residue in soil was below 0.24 mg·kg-1, soil actinomycetes community was higher than control without bio-char, bacteria increased first and then reduced after adding carbon as below 0.12 mg·kg-1. Biochar was ‘deep hole’ structure containing C, O, S and other elements. The results showed that a certain concentration clomazone residue in soil would stimulate soil fungi and actinomycetes to grow. After adding the biochar, the inhibition effect of high herbicides residual on bacterial would be alleviated.

  2. Pyrolysis of hornbeam (Carpinus betulus L.) sawdust: Characterization of bio-oil and bio-char.

    Science.gov (United States)

    Moralı, Uğur; Yavuzel, Nazan; Şensöz, Sevgi

    2016-12-01

    Slow pyrolysis of hornbeam (Carpinus betulus L.) sawdust was performed to produce bio-oil and bio-char. The operational variables were as follows: pyrolysis temperature (400-600°C), heating rate (10-50°Cmin(-1)) and nitrogen flow rate (50-150cm(3)min(-1)). Physicochemical and thermogravimetric characterizations of hornbeam sawdust were performed. The characteristics of bio-oil and bio-char were analyzed on the basis of various spectroscopic and chromatographic techniques such as FTIR, GC-MS, 1H NMR, SEM, BET. Higher heating value, density and kinematic viscosity of the bio-oil with maximum yield of 35.28% were 23.22MJkg(-1), 1289kgm(-3) and 0.6mm(2)s(-1), respectively. The bio-oil with relatively high fuel potential can be obtained from the pyrolysis of the hornbeam sawdust and the bio-char with a calorific value of 32.88MJkg(-1) is a promising candidate for solid fuel applications that also contributes to the preservation of the environment.

  3. Sampling large geographic areas for rare species using environmental DNA: a study of bull trout Salvelinus confluentus occupancy in western Montana.

    Science.gov (United States)

    McKelvey, K S; Young, M K; Knotek, W L; Carim, K J; Wilcox, T M; Padgett-Stewart, T M; Schwartz, M K

    2016-03-01

    This study tested the efficacy of environmental DNA (eDNA) sampling to delineate the distribution of bull trout Salvelinus confluentus in headwater streams in western Montana, U.S.A. Surveys proved fast, reliable and sensitive: 124 samples were collected across five basins by a single crew in c. 8 days. Results were largely consistent with past electrofishing, but, in a basin where S. confluentus were known to be scarce, eDNA samples indicated that S. confluentus were more broadly distributed than previously thought.

  4. Stable Carbon Isotopic Fractionation in Smoke and Char Produced During Biomass Burning

    Science.gov (United States)

    Wang, Y.; Hsieh, Y.

    2006-12-01

    Stable isotopic ratio of carbon has been used extensively as a tracer of carbon sources in the environment. It has been documented that burning of C4 grasses resulted in significant depletion of C13 in the charcoal while burning of wood and C3 grass did not. This study was initiated to investigate the stable carbon isotopic fractionation of the smoke and char produced during biomass burnings. Samples of Juncus romerianus (C3 salt marsh grass) and Spartina alterniflora (C4 salt marsh grass), Eremochloa ophiuroides (centipede, a C4 lawn grass) and woody debris of a pine forest were colleted and burned in open air fire place. The particulate matter with diameters less than 2.5 micron (PM2.5) emitted from the burning was collected using a PM sampler. The original biomass, PM2.5, black C in PM2.5 and char (ash) were analyzed for their C, N and S thermograms using a multi-elemental scanning thermal analyzer and their stable C isotopic ratios were measured using an EA-IRMS. The results indicate that burning of wood and C3 grass did not produce significant C isotopic fractionation in PM2.5, black C in PM2.5 and char with respect to the original material. However, there was a significant C13-depletion in PM2.5 (-6.2 per mil), black C in PM2.5 (-4.6 per mil) and chars (-4.6 per mil) produced by burning of the C4 centipede grass; whereas the C4 Spartina salt marsh grass produced a C13-depletion in PM2.5 (-2.3 per mil) and black C in PM2.5 (-3.6 per mil), and a slight C13-enrichment in char (0.5 per mil). The isotope fractionation associated with burning of C4 vegetation is probably dependent on species and burning conditions and warrant further study.

  5. 共热解过程对褐煤焦和生物质焦氧化特性的影响%Effect of co-pyrolysis process on the oxidation reactivity of lignite char and biomass char

    Institute of Scientific and Technical Information of China (English)

    郭沛; 赵慧明; 贾挺豪; 王美君; 常丽萍

    2015-01-01

    Ximeng lignite and cornstalk were used as the feedstock to prepare lignite char, biomass char and co-pyrolysis char with different blending ratios in a fixed bed reactor with temperature-programmed pyrolysis. The pore and chemical structure of char samples were characterized and the ash composition was analyzed. The oxidation reactivity of the mixtures of lignite char/cornstalk char with different blending ratios and the co-pyrolysis char of lignite and cornstalk with corresponding blending ratios were investigated by the isothermal thermogravimetry at 450℃, aimed at the effect of co-pyrolysis process on the char reactivity. The results show that there are obvious influences on the char structures through secondary reactions during co-pyrolysis process, leading to the char reactivity decrease. Especially with the cornstalk proportion less than 50%, these influences are more significant due to a large number of volatiles from cornstalk during co-pyrolysis enhancing the secondary reactions between the volatile and nascent char, prompting parts of organic structure less than 5 rings turn into the larger organic structure. For the char samples with cornstalk proportion above 50%, the catalytic effect of alkaline and alkaline earth metal in biomass char plays a dominating role, especially the effect of potassium, resulting in the weaker effects of secondary reactions on the structure and oxidation reactivity of the char samples.%以锡盟褐煤和玉米秸秆为原料,利用固定床程序升温热解的方法制备了褐煤焦、生物质焦以及褐煤和生物质不同混合比例的共热解焦样,并进行了孔结构和化学结构的表征以及其灰成分分析。采用等温热重法在450℃下考察褐煤焦和生物质焦的混合样与其相同比例的共热解焦样的氧化活性,对比分析共热解过程对焦样反应活性的影响。实验结果表明,共热解过程中的二次反应对焦样结构有着明显的影响,进一步导

  6. Suprasubduction volcanic rocks of the Char ophiolite belt, East Kazakhstan: new geochemical and first geochronological data

    Science.gov (United States)

    Safonova, Inna; Simonov, Vladimir; Seltmann, Reimar; Yamamoto, Shinji; Xiao, Wenjiao

    2016-04-01

    The Char ophiolite belt is located in the western Central Asian Orogenic Belt, a world largest accretionary orogen, which has evolved during more than 800 Ma. The Char belt formed during Kazakhstan - Siberia collision. It has been known for hosting fragments of Late Devonian-Early Carboniferous oceanic crust, MORB, OPB and OIB, of the Paleo-Asian Ocean (Safonova et al., 2012). The Char is surrounded by two Paleozoic island-arc terranes: Zharma-Saur in the west and Rudny Altai in the east, however, until recent times, no island-arc units have been found within it. We were the first to find island-arc units as tectonic sheets occurring adjacent to those consisting of oceanic rocks. In places, island-arc andesites cut oceanic basalts. The Char volcanic and subvolcanic rocks of a probable suprasubduction origin are basalt, microgabbro, dolerite, andesite, tonalite and dacite. The mafic to andesitic volcanics possessing low TiO2 (0.85 wt.%av.) and show MgO vs. major elements crystallization trends suggesting two magma series: tholeiitic and calc-alkaline. The tholeiitic varieties are less enriched in incompatible elements then the calc-alkaline ones. Two samples are high-Mg and low-Ti andesibasalts similar to boninites. The rocks possess moderately LREE enriched rare-earth element patterns and are characterized by negative Nb anomalies present on the multi-element spectra (Nb/Lapm = 0.14-0.47; Nb/Thpm = 0.7-1.6).The distribution of rare-earth elements (La/Smn = 0.8-2.3, Gd/Ybn = 0.7-1.9) and the results of geochemical modeling in the Nb-Yb system suggest high degrees of melting of a depleted harzburgite-bearing mantle source at spinel facies depths. Fractional crystallization of clinopyroxene, plagioclase and opaque minerals also affected the final composition of the volcanic rocks. Clinopyroxene monomineral thermometry indicates crystallization of melts at 1020-1180°C. Melt inclusion composition based numerical calculations show that primary melts were derived at 1350

  7. Carbonisation of bagasse in a fixed bed reactor: influence of process variables on char yield and characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Katyal, S.; Thambimuthu, K.; Valix, M. [University of Sydney (Australia). Dept. of Chemical Engineering

    2003-04-01

    Carbonisation experiments on samples of sugar cane bagasse were conducted in a static fixed bed reactor to determine the effect of process variables such as temperature, heating rate, inert sweep gas flow rate and particle size on the yield and composition of solid product char. Experiments were performed to the final temperatures of 250-700{sup o}C with heating rates from 5 to 30{sup o}C/min with nitrogen sweep gas flow rate of 350 cc/min. Additional tests were aimed at studying the effect of different flow rates of nitrogen sweep gas from 0 to 700 cc/min during carbonization and different particle size fractions of bagasse. The results showed that as the carbonisation temperature was increased, the yield of char decreased. The reduction in yield was rapid up to a final temperature of 500{sup o}C and was slower thereafter. The yield of char was relatively insensitive to the changes in heating rate and particle size. Increasing the sweep gas flow rate to 350 cc/min reduced the yield of char. It appears the presence of inert sweep gas reduced secondary reactions which promoted char formation. The proximate analysis of the char suggests that fixed carbon and ash content increased with temperature. The char obtained at temperatures higher than 500{sup o}C have high carbon content and is suitable as renewable fuel and for other applications. The carbonization of bagasse has the potential to produce environmental friendly fuels and can assist in reducing deforestation for the production of charcoal. (Author)

  8. Bull trout (Salvelinus confluentus) movement in relation to water temperature, season, and habitat features in Arrowrock Reservoir, Idaho, 2012

    Science.gov (United States)

    Maret, Terry R.; Schultz, Justin E.

    2013-01-01

    Acoustic telemetry was used to determine spring to summer (April–August) movement and habitat use of bull trout (Salvelinus confluentus) in Arrowrock Reservoir (hereafter “Arrowrock”), a highly regulated reservoir in the Boise River Basin of southwestern Idaho. Water management practices annually use about 86 percent of the reservoir water volume to satisfy downstream water demands. These practices might be limiting bull trout habitat and movement patterns. Bull trout are among the more thermally sensitive coldwater species in North America, and the species is listed as threatened throughout the contiguous United States under the Endangered Species Act. Biweekly water-temperature and dissolved-oxygen profiles were collected by the Bureau of Reclamation at three locations in Arrowrock to characterize habitat conditions for bull trout. Continuous streamflow and water temperature also were measured immediately upstream of the reservoir on the Middle and South Fork Boise Rivers, which influence habitat conditions in the riverine zones of the reservoir. In spring 2012, 18 bull trout ranging in total length from 306 to 630 millimeters were fitted with acoustic transmitters equipped with temperature and depth sensors. Mobile boat tracking and fixed receivers were used to detect released fish. Fish were tagged from March 28 to April 20 and were tracked through most of August. Most bull trout movements were detected in the Middle Fork Boise River arm of the reservoir. Fifteen individual fish were detected at least once after release. Water surface temperature at each fish detection location ranged from 6.0 to 16.2 degrees Celsius (°C) (mean=10.1°C), whereas bull trout body temperatures were colder, ranging from 4.4 to 11.6°C (mean=7.3°C). Bull trout were detected over deep-water habitat, ranging from 8.0 to 42.6 meters (m) (mean=18.1 m). Actual fish depths were shallower than total water depth, ranging from 0.0 to 24.5 m (mean=6.7 m). The last bull trout was

  9. 生物质半焦的催化气化动力学特性%Catalytic gasification kinetics of biomass semi-char

    Institute of Scientific and Technical Information of China (English)

    肖瑞瑞; 杨伟; 于广锁

    2013-01-01

    The reaction kinetics of straw catalytic gasification was investigated in a thermogravimetric analyzer. Also the catalytic gasification of char from co-gasification of petroleum coke and biomass was studied. A modified random pore model was used to correlate the relationship between gasification rate and carbon conversion rate. The apparent activation energy and pre-exponential factors of biomass with different catalysts were obtained. The results indicated that the gasification activity of biomass semi-char with catalysts was enhanced apparently. The catalytic activity order of different chars was found to be K-char>Ca-char> Mg-char>raw-char>acid washing-char. The increase of the gasification rate of petroleum coke blended with biomass indicated that the gasification reaction is enhanced by biomass char. The apparent activation energy order of different chars in gasification is K-charchar. The activation energy of petroleum coke gasification dropped if blended with biomass char.%采用恒温热重分析法对稻草的催化气化反应动力学进行了研究,同时研究了生物质对石油焦气化的催化作用.采用修正随机孔模型对气化反应转化速率与转化率的关系进行了拟合计算,得到生物质焦气化的活化能和指前因子.结果表明,加入催化剂后半焦的气化反应活性增大,活性顺序为:加入K+半焦>加入Ca2+半焦>加入Mg2+半焦>原半焦>酸洗后半焦,表明了生物质焦能明显提高石油焦的气化活性.不同半焦气化的活化能大小顺序为:加入K+半焦<加入Ca2+半焦<加入Mg2+半焦<原半焦<酸洗后半焦,表明了生物质半焦的加入能降低石油焦气化的活化能.

  10. Use of the Rigor Mortis Process as a Tool for Better Understanding of Skeletal Muscle Physiology: Effect of the Ante-Mortem Stress on the Progression of Rigor Mortis in Brook Charr (Salvelinus fontinalis).

    Science.gov (United States)

    Diouf, Boucar; Rioux, Pierre

    1999-01-01

    Presents the rigor mortis process in brook charr (Salvelinus fontinalis) as a tool for better understanding skeletal muscle metabolism. Describes an activity that demonstrates how rigor mortis is related to the post-mortem decrease of muscular glycogen and ATP, how glycogen degradation produces lactic acid that lowers muscle pH, and how…

  11. Determination of the intrinsic reactivities for carbon dioxide gasification of rice husk chars through using random pore model.

    Science.gov (United States)

    Gao, Xiaoyan; Zhang, Yaning; Li, Bingxi; Zhao, Yijun; Jiang, Baocheng

    2016-10-01

    Rice husk is abundantly available and environmentally friendly, and char-CO2 gasification is of great importance for the biomass gasification process. The intrinsic reaction rates of carbon dioxide gasification with rice husk chars derived from different pyrolysis temperatures were investigated in this study by conducting thermogravimetric analysis (TGA) measurements. The effects of gasification temperature and reactant partial pressure on the char-CO2 gasification were investigated and the random pore model (RPM) was used to determine the intrinsic kinetic parameters based on the experimental data. The results obtained from this study show that the activation energy, reaction order and pre-exponential factor varied in the ranges of 226.65-232.28kJ/mol, 0.288-0.346 and 2.38×10(5)-2.82×10(5)1/sPa(n) for the rice husk chars pyrolyzed at 700-900°C, respectively. All the determination coefficients between the RPM predictions and experimental results were higher than 0.906, indicating the RPM is reliable for determining and evaluating the intrinsic reactivities of rice husk chars.

  12. Effect of Kaolin Clay and Alumina on Thermal Performance and Char Morphology of Intumescent fire retardant coating

    Directory of Open Access Journals (Sweden)

    aziz Hammad

    2014-07-01

    Full Text Available Intumescent fire retardant coating (IFRC have been developed by using ammonium polyphosphate, expandable graphite, melamine, boric acid, kaolin clay and alumina as fillers bound together with epoxy resin and cured with the help of curing agent. Five different formulations were developed with and without using fillers. Cured samples were burned in furnace at 500°C for 2h for char expansion. Bunsen burner test was performed for 1h using UL-94 vertical burning test to investigate the thermal performance of IFRC. The resultant char obtained after burning of coated samples were characterized by using field emission scanning electron microscopy for char morphology. Char composition was analyzed by using fourier transform infrared spectroscopy. Thermogravimetric analysis was carried out to investigate the residual weight of coating. Results showed that formulation with 0.5 weight % of kaolin clay and 0.5 weight % of alumina provide best thermal performance, uniform and multi-porous char structure with high anti-oxidation property.

  13. A Study on the Applicability of Kinetic Models for Shenfu Coal Char Gasification with CO2 at Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Jinsheng Gao

    2009-07-01

    Full Text Available In this paper, measurements of the CO2 gasification kinetics for two types of Shenfu coal chars, which were respectively prepared by slow and rapid pyrolysis at temperatures of 950 °C and 1,400 °C, were performed by an isothermal thermo-gravimetric analysis under ambient pressure and elevated temperature conditions. Simultaneously, the applicability of the kinetic model for the CO2 gasification reaction of Shenfu coal chars was discussed. The results showed: (i the shrinking un-reacted core model was not appropriate to describe the gasification reaction process of Shenfu coal chars with CO2 in the whole experimental temperature range; (ii at the relatively low temperatures, the modified volumetric model was as good as the random pore model to simulate the CO2 gasification reaction of Shenfu coal chars, while at the elevated temperatures, the modified volumetric model was superior to the random pore model for this process; (iii the integral expression of the modified volumetric model was more favorable than the differential expression of that for fitting the experimental data. Moreover, by simply introducing a function: A = A★exp(ft, it was found that the extensive model of the modified volumetric model could make much better predictions than the modified volumetric model. It was recommended as a convenient empirical model for comprehensive simulation of Shenfu coal char gasification with under conditions close to those of entrained flow gasification.

  14. The effect of temperature and heating rate on char properties obtained from solar pyrolysis of beech wood.

    Science.gov (United States)

    Zeng, Kuo; Minh, Doan Pham; Gauthier, Daniel; Weiss-Hortala, Elsa; Nzihou, Ange; Flamant, Gilles

    2015-04-01

    Char samples were produced from pyrolysis in a lab-scale solar reactor. The pyrolysis of beech wood was carried out at temperatures ranging from 600 to 2000°C, with heating rates from 5 to 450°C/s. CHNS, scanning electron microscopy analysis, X-ray diffractometry, Brunauer-Emmett-Teller adsorption were employed to investigate the effect of temperature and heating rate on char composition and structure. The results indicated that char structure was more and more ordered with temperature increase and heating rate decrease (higher than 50°C/s). The surface area and pore volume firstly increased with temperature and reached maximum at 1200°C then reduced significantly at 2000°C. Besides, they firstly increased with heating rate and then decreased slightly at heating rate of 450°C/s when final temperature was no lower than 1200°C. Char reactivity measured by TGA analysis was found to correlate with the evolution of char surface area and pore volume with temperature and heating rate.

  15. Flat-flame burner studies of pulverized-coal combustion. Experimental results on char reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Peck, R.E.; Shi, L.

    1996-12-01

    Structure of laminar, premixed pulverized-coal flames in a 1-D reactor has been studied with emphasis on char reactivity. A 1.1-meter-long tube furnace accommodated high-temperature environments and long residence times for the laminar flames produced by a flat-flame, coal-dust burner. Experiments were conducted at different operating conditions (fuel type/size, fuel-air ratio). Measurements included solid sample composition, major gas species and hydrocarbon species concentrations, and gas- and particle-phase line-of-sight temperatures at different axial locations in flames. Degree of char burnout increased with coal volatiles content and decreased with coal particle size. Combustion in furnace was in oxidizer-deficient environment and higher burnout was achieved as the fuel-air ratio neared stoichiometric. For 0-45 {mu}m particles most of the fixed carbon mass loss occurred within 5 cm of the furnace inlet, and char reaction was slow downstream due to low oxidizer concentrations. Fixed carbon consumption of the 45-90 {mu}m particles generally was slower than for the small particles. About 40%-80% of the fixed carbon was oxidized in the furnace. Primary volatiles mass loss occurred within the first 4.5 cm, and more than 90% of the volatiles were consumed in the flames. The flames stabilized in the furnace produced less CH{sub 4} and H{sub 2} in the burnt gas than similar unconfined flames. NO concentrations were found to decrease along the furnace and to increase with decreasing fuel/air ratio. Temperature measurement results showed that gas-phase temperatures were higher than solid-phase temperatures. Temperatures generally decreased with decreasing volatiles content and increased as the equivalence ratio approached one. The results can be used to interpret thermochemical processes occurring in pulverized-coal combustion. (au) 15 refs.

  16. Inverse Heat Conduction Methods in the CHAR Code for Aerothermal Flight Data Reconstruction

    Science.gov (United States)

    Oliver, A. Brandon; Amar, Adam J.

    2016-01-01

    Reconstruction of flight aerothermal environments often requires the solution of an inverse heat transfer problem, which is an ill-posed problem of determining boundary conditions from discrete measurements in the interior of the domain. This paper will present the algorithms implemented in the CHAR code for use in reconstruction of EFT-1 flight data and future testing activities. Implementation details will be discussed, and alternative hybrid-methods that are permitted by the implementation will be described. Results will be presented for a number of problems.

  17. Measurements and modeling of pulverized fuel char in an entrained flow reactor

    Science.gov (United States)

    Kebria, Mazdak

    In recent years, the combustion zone of utility boilers were modified for NOx control and this made the task of maintaining low residual carbon levels in boiler fly ash much more difficult. To predict the relationships between boiler operating conditions and residual carbon-in-ash, there is a need for improvements in determining the appropriate char reactivity to use in simulating coal-fired combustors and in relating this reactivity to unburned coal characteristics. To aid in this effort, a tubular, downward-fired, refractory-lined, laminar entrained flow reactor (EFR) was built to provide a pilot scale environment with 2 seconds residence time for studying coal combustion. Using a commercial CFD code (FLUENT), a three dimensional numerical model of coal burning in the EFR was created to evaluate common char burnout kinetic modeling approaches. EFR experimental data was obtained for operating conditions adjusted to reproduce particle Lagrangian temperature and oxygen concentration time histories typically found in coal-fired utility boilers. The radial temperature profiles were measured at different axial locations in the EFR with a suction pyrometer and thermocouples. The temperature distribution in the reactor agreed well with the simulations. A gas analyzer with a quenching probe was used to measure the oxygen distribution to similarly confirm oxygen distribution in the EFR. A semi-isokinetic particulate sampling probe was used to extract ash samples at different heights in the reactor to measure the evolution of loss on ignition (LOI). Measured LOI values were used to validate the model against predicted values. Reaction kinetics rates in the model were adjusted to bring agreement between calculated LOI and the measured values from the experimental results. The LOI predictions by kinetic-diffusion and CBK model are very similar at the late stage of char burnout. The results indicate that we can achieve sufficient accuracy for the prediction of final carbon

  18. Char BC amendments for soil and sediment amelioration: BC quantification and field pilot trials

    Science.gov (United States)

    Cornelissen, G.; Braendli, R. C.; Eek, E.; Henriksen, T.; Hartnik, T.; Breedveld, G. D.

    2008-12-01

    Background Activated char BC binds organic contaminants and possibly mercury so strongly that their bioaccumulation and transport to other environmental compartments are reduced. The advantages of black carbon amendment over many other remediation methods include i) it can be used as an in situ risk reduction method, ii) the price is low, and iii) it overcomes significant controversies associated with disposal of dredged and excavated materials. In this study BC amendment is used in pilot trials in the field for soil and sediment amelioration. Quantification of amended char BC Two methods for char BC quantification were tested: i) chemothermal oxidation (CTO) at a range of temperatures and ii) wet chemical oxidation with a potassium dichromate/sulfuric acid solution. The amount of BC amended to three soils was accurately determined by CTO at 375°C. For two sediments, much of the BC disappeared during combustion at 375°C, which could probably be explained by catalytic effects caused by sediment constituents such as metals, mineral oxides and salts. Attempts to avoid these effects through rinsing with acid before combustion did not result in higher char BC recoveries. CTO at lower temperatures (325-350°C) was a feasible alternative for one of the sediments. Wet oxidation with potassium dichromate/sulfuric acid proved to effectively function for BC quantification in sediments, since almost complete BC recovery (81-92 %) was observed for both sediments, while the amount of organic carbon remaining was low (5-16 %). Field pilots Earlier, we showed the effectiveness of BC amendment in the laboratory. In the laboratory it was shown that BC amendments (2 %) reduced freely dissolved porewater concentrations (factor of 10-50) and bioaccumulation (factor of 5). This presentation will describe 50 × 50 m pilot field trials in Norway (2007-2008): Trondheim Harbor (sediment) and Drammen (soil). The presentation will focus on physical monitoring (distribution of BC in the

  19. Importance of fragmentation on the steady state combustion of wood char in a bubbling fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Pinho, Carlos [Universidade do Porto (CEFT/FEUP), Porto (Portugal). Faculdade de Engenharia. Centro de Estudos de Fenomenos de Transporte], E-mail: ctp@fe.up.pt

    2010-07-01

    A simple mathematical model for the analysis of the steady state behavior of a bubbling fluidized bed burner is presented, with the main intention of evaluating the importance of the primary fragmentation of fuel particles on the performance of this type of burners. This model has pedagogical advantages because of its simplicity and easiness of application to the analysis of realistic situations. The model is based upon the classical models used for the study of batch combustion processes in fluidized bed reactors. Experimental data from studies of fluidized bed combustion of portuguese vegetable chars are used to support the analysis of the performance of a 1 m diameter fluidized bed combustor. (author)

  20. Prediction and validation of burnout curves for Goettelborn char using reaction kinetics determined in shock tube experiments

    Energy Technology Data Exchange (ETDEWEB)

    Moors, J.H.J.; Banin, V.E.; Haas, J.H.P.; Weber, R.; Veefkind, A. [Eindhoven University of Technology, Eindhoven (Netherlands). Dept. of Applied Physics

    1999-01-01

    Using a shock tube facility the combustion characteristics of pulverised char ({lt} 10 {mu}m) were measured. A prediction was made for the burnout behaviour of a commercial sized char particle (75-90 {mu}m) in different ambient conditions using a `pseudo kinetic` approach. In this approach the kinetic rate of a surface containing micro pores is determined and these `pseudo kinetics` are then applied to the larger particle not taking into account the micro pores. Comparison of the predictions with measurements done with an isothermal plug flow reactor showed this approach to be valid within experimental error for low burnout. A linear decrease of the kinetic reaction rate with burnout is shown to predict the burnout behaviour in the complete range of burnout. A possible explanation for this linear decrease could be a growing fraction of non-combustible material in the char particles during burnout. 11 refs., 6 figs., 2 tabs.

  1. Carbon Sequestration and Nitrogen Mineralization in Soil Cooperated with Organic Composts and Bio-char During Corn (Zea mays) Cultivation

    Science.gov (United States)

    Shin, Joung-Du; Lee, Sun-Ill; Park, Wu-Gyun; Choi, Yong-Su; Hong, Seong-Gil; Park, Sang-Won

    2014-05-01

    Objectives of this study were to estimate the carbon sequestration and to evaluate nitrogen mineralization and nitrification in soils cooperated with organic composts and bio-char during corn cultivation. For the experiment, the soil used in this study was clay loam types, and application rates of chemical fertilizer and bio-char were recommended amount after soil test and 2 % to soil weight, respectively. The soil samples were periodically taken at every 15 day intervals during the experimental periods. The treatments were consisted of non-application, cow manure compost, pig manure compost, swine digestate from aerobic digestion system, their bio-char cooperation. For the experimental results, residual amount of inorganic carbon was ranged from 51 to 208kg 10a-1 in soil only cooperated with different organic composts. However it was estimated to be highest at 208kg 10a-1 in the application plot of pig manure compost. In addition to bio-char application, it was ranged from 187.8 to 286kg 10a-1, but was greatest accumulated at 160.3kg 10a-1 in the application plot of cow manure compost. For nitrogen mineralization and nitrification rates, it was shown that there were generally low in the soil cooperated with bio-char compared to the only application plots of different organic composts except for 71 days after sowing. Also, they were observed to be highest in the application plot of swine digestate from aerobic digestion system. For the loss of total inorganic carbon (TIC) by run-off water, it was ranged from 0.18 to 0.36 kg 10a-1 in the different treatment plots. Also, with application of bio-char, total nitrogen was estimated to be reduced at 0.42(15.1%) and 0.38(11.8%) kg 10a-1 in application plots of the pig manure compost and aerobic digestate, respectively.

  2. Arsenic(V) biosorption by charred orange peel in aqueous environments.

    Science.gov (United States)

    Abid, Muhammad; Niazi, Nabeel Khan; Bibi, Irshad; Farooqi, Abida; Ok, Yong Sik; Kunhikrishnan, Anitha; Ali, Fawad; Ali, Shafaqat; Igalavithana, Avanthi Deshani; Arshad, Muhammad

    2016-01-01

    Biosorption efficiency of natural orange peel (NOP) and charred orange peel (COP) was examined for the immobilization of arsenate (As(V)) in aqueous environments using batch sorption experiments. Sorption experiments were carried out as a function of pH, time, initial As(V) concentration and biosorbent dose, using NOP and COP (pretreated with sulfuric acid). Arsenate sorption was found to be maximum at pH 6.5, with higher As(V) removal percentage (98%) by COP than NOP (68%) at 4 g L(-1) optimum biosorbent dose. Sorption isotherm data exhibited a higher As(V) sorption (60.9 mg g(-1)) for COP than NOP (32.7 mg g(-1)). Langmuir model provided the best fit to describe As(V) sorption. Fourier transform infrared spectroscopy and scanning electron microscopy combined with energy dispersive X-ray spectroscopy analyses revealed that the -OH, -COOH, and -N-H surface functional groups were involved in As(V) biosorption and the meso- to micro-porous structure of COP sequestered significantly (2-times) higher As(V) than NOP, respectively. Arsenate desorption from COP was found to be lower (10%) than NOP (26%) up to the third regeneration cycle. The results highlight that this method has a great potential to produce unique 'charred' materials from the widely available biowastes, with enhanced As(V) sorption properties.

  3. Study of nonisothermal reduction of iron ore-coal/char composite pellet

    Science.gov (United States)

    Dutta, S. K.; Ghosh, A.

    1994-01-01

    Cold-bonded composite pellets, consisting of iron ore fines and fines of noncoking coal or char, were prepared by steam curing at high pressure in an autoclave employing inorganic binders. Dry compressive strength ranged from 200 to 1000 N for different pellets. The pellets were heated from room temperature to 1273 K under flowing argon at two heating rates. Rates of evolution of product gases were determined from gas Chromatographie analysis, and the temperature of the sample was monitored by thermocouple as a function of time during heating. Degree of reduction, volume change, and compressive strength of the pellets upon reduction were measured subsequently. Degree of reduction ranged from 46 to 99 pct. Nonisothermal devolatilization of coal by this procedure also was carried out for comparison. It has been shown that a significant quantity (10 to 20 pct of the pellet weight) of extraneous H2O and CO2 was retained by dried pellets. This accounted for the generation of additional quantities of H2 and CO during heating. Carbon was the major reductant, but reduction by H2 also was significant. Ore-coal and ore-char composites exhibited a comparable degree of reduction. However, the former showed superior postreduction strength due to a smaller amount of swelling upon reduction.

  4. Utilization of palm oil sludge through pyrolysis for bio-oil and bio-char production.

    Science.gov (United States)

    Thangalazhy-Gopakumar, Suchithra; Al-Nadheri, Wail Mohammed Ahmed; Jegarajan, Dinesh; Sahu, J N; Mubarak, N M; Nizamuddin, S

    2015-02-01

    In this study, pyrolysis technique was utilized for converting palm oil sludge to value added materials: bio-oil (liquid fuel) and bio-char (soil amendment). The bio-oil yield obtained was 27.4±1.7 wt.% having a heating value of 22.2±3.7 MJ/kg and a negligible ash content of 0.23±0.01 wt.%. The pH of bio-oil was in alkaline region. The bio-char yielded 49.9±0.3 wt.%, which was further investigated for sorption efficiency by adsorbing metal (Cd(2+) ions) from water. The removal efficiency of Cd(2+) was 89.4±2%, which was almost similar to the removal efficiency of a commercial activated carbon. The adsorption isotherm was well described by Langmuir model. Therefore, pyrolysis is proved as an efficient tool for palm oil sludge management, where the waste was converted into valuable products.

  5. Advanced char burnout models for the simulation of pulverized coal fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    T. Severin; S. Wirtz; V. Scherer [Ruhr-University, Bochum (Germany). Institute of Energy Plant Technology (LEAT)

    2005-07-01

    The numerical simulation of coal combustion processes is widely used as an efficient means to predict burner or system behaviour. In this paper an approach to improve CFD simulations of pulverized coal fired boilers with advanced coal combustion models is presented. In simple coal combustion models, first order Arrhenius rate equations are used for devolatilization and char burnout. The accuracy of such simple models is sufficient for the basic aspects of heat release. The prediction of carbon-in-ash is one aspect of special interest in the simulation of pulverized coal fired boilers. To determine the carbon-in-ash levels in the fly ash of coal fired furnaces, the char burnout model has to be more detailed. It was tested, in how far changing operating conditions affect the carbon-in-ash prediction of the simulation. To run several test cases in a short time, a simplified cellnet model was applied. To use a cellnet model for simulations of pulverized coal fired boilers, it was coupled with a Lagrangian particle model, used in CFD simulations, too. 18 refs., 5 figs., 5 tabs.

  6. Char crystalline transformations during coal combustion and their implications for carbon burnout

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.H.

    1999-03-11

    Residual, or unburned carbon in fly ash affects many aspects of power plant performance and economy including boiler efficiency, electrostatic precipitator operation, and ash as a salable byproduct. There is a large concern in industry on the unburned carbon problem due to a variety of factors, including low-NOx combustion system and internationalization of the coal market. In recent work, it has been found that residual carbon extracted from fly ash is much less reactive than the laboratory chars on which the current kinetics are based. It has been suggested that thermal deactivation at the peak temperature in combustion is a likely phenomenon and that the structural ordering is one key mechanism. The general phenomenon of carbon thermal annealing is well known, but there is a critical need for more data on the temperature and time scale of interest to combustion. In addition, high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars, has become available. Motivated by these new developments, this University Coal Research project has been initiated with the following goals: to determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history; and to characterize the effect of this thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis.

  7. Char crystalline transformations during coal combustion and their implications for carbon burnout

    Energy Technology Data Exchange (ETDEWEB)

    Hurt, R.H.

    1999-07-07

    Residual, or unburned carbon in fly ash affects many aspects of power plant performance and economy including boiler efficiency, electrostatic precipitator operation, and ash as a salable byproduct. There is a large concern in industry on the unburned carbon problem due to a variety of factors, including low-NOx combustion system and internationalization of the coal market. In recent work, it has been found that residual carbon extracted from fly ash is much less reactive than the laboratory chars on which the current kinetics are based. It has been suggested that thermal deactivation at the peak temperature in combustion is a likely phenomenon and that the structural ordering is one key mechanism. The general phenomenon of carbon thermal annealing is well known, but there is a critical need for more data on the temperature and time scale of interest to combustion. In addition, high resolution transmission electron microscopy (HRTEM) fringe imaging, which provides a wealth of information on the nature and degree of crystallinity in carbon materials such as coal chars, has become available. Motivated by these new developments, this University Coal Research project has been initiated with the following goals: (1) To determine transient, high-temperature, thermal deactivation kinetics as a function of parent coal and temperature history. (2) To characterize the effect of the thermal treatment on carbon crystalline structure through high-resolution transmission electron microscopy and specialized, quantitative image analysis.

  8. Key parameters influencing the NOx reduction process by low-cost char pellets: An overview

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Soriano-Mora; A. Bueno-Lopez; A. Garcia-Garcia; R. Perry; C.E. Snape [University of Alicante, Alicante (Spain). Dept. of Inorganic Chemistry

    2007-07-01

    High potassium content char briquettes prepared from a bituminous coal have shown to be remarkably selective towards NOx reduction by the carbon contained within them. For the present work, it was decided to pursue the preparation of a number of pelletised formulations as well as testing reaction temperatures and lifetime tests. Low-cost carbon feedstocks were selected for pellet preparation (a metallurgical coke breeze, petroleum coke fines and a medium temperature domestic coke), two coals (an anthracite and a high volatile bituminous coal), a scrap tyre pyrolysis char and a carbon concentrate from PFA. Pellets were prepared from a solid mixture containing 65% of air-dried carbon, 30% potassium hydroxide and 5% of cashew nut shell liquid as binder. The results show that good and constant values of NOx reduction are kept after 2 hours of reaction as well as satisfactory selectivity factors (up to 0.45). This parameter is highly dependent on potassium content of the samples and on reaction temperature. The most efficient pellets in terms of high selectivity and high amount of NOx reduced were analysed under lifetime tests at 400{sup o}C. Very encouraging results were obtained showing that high values of NOx conversions (well above O{sub 2} conversions), long lifetimes, no uncontrolled increase in sample temperature and very low CO emissions, (leading to an optimum sample efficiency) were observed throughout lifetime tests. 4 refs., 4 figs., 5 tabs.

  9. Biochemical stability of sewage sludge chars and their impact on soil organic matter of a Mediterranean Cambisol

    Science.gov (United States)

    Paneque, Marina; María De la Rosa, José; Aragón, Carlos; Kern, Jürgen; Knicker, Heike

    2016-04-01

    Transformation of sewage sludge (SS) into char achieves sludge hygienisation, which is necessary prior its application into agricultural soils. The pyrolysis of SS increases its stability in a degree which depends on the thermal treatment used. Thus, chars produced by using hydrothermal carbonization are typically more stable than normal soil organic matter (SOM), but less stable than chars from dry pyrolysis (Libra et al., 2011). Addition of highly-recalcitrant SS-chars to soil will likely increase its carbon sequestration potential; however the fertilizing properties of SS may be compromised due to its alteration during the pyrolysis. The main goal of this work was to investigate the biochemical recalcitrance of two 13C-enriched SS-chars once applied in a Mediterranean Cambisol as well as to evaluate their impact on the SOM quality and carbon stability. Thus, we studied the distribution of 13C between plants and soil after the addition of the 13C-enriched chars (2 atm%) to the soil. Therefore, we performed a greenhouse incubation experiment, using a Mediterranean Cambisol as matrix and tested the following treatments: control (soil alone), raw SS, SS-hydrochar, SS-pyrochar. The SS was produced in a pilot-scale waste-water plant and enriched with 13C by the addition of 13C-glucose during the treatment. The amendment was only applied to the upper 2 cm of the soil matrix where it accounted for 5% of its dry weight. Per pot, 25 seeds of Lolium perenne were sowed and incubated under controlled conditions. The biomass production as well as the concentration of 13C in leaves and roots was determined after 1, 2 and 5 months. The partitioning of the 13C between soil and plant and its transformation into bioavailable forms were monitored by stable isotopic mass spectrometry. The 13C-enrichment of the chars allowed the use of solid-state 13C NMR spectroscopy as a means for the detection of chemical alterations of the chars during their aging. Libra J., Ro K., Kammann C

  10. Ignition Properties of Thermally Thin Plastics: The Effectiveness of Non-Competitive Char Formation in Reducing Flammability

    OpenAIRE

    Nelson, M. I.; Brindley, J.; McIntosh, A. C.

    2002-01-01

    The retardancy effect of char formation upon the flammability of thermally thin products is investigated. The char is formed in a single-step non-competitive scheme and is assumed to be thermally stable. The criterion for ignition is that of a critical mass flux of volatiles from the solid into the gas phase. Both steady-state and transient formulations of the model are considered. In the high activation energy limit the critical heat flux efficiency in the steady-state model is p...

  11. Shape-controlled Synthesis of Activated Bio-chars by Surfactant-templated Ionothermal Carbonization in Acidic Ionic Liquid and Activation with Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Feng Guo

    2014-04-01

    Full Text Available Shape-controlled bio-chars were synthesized in two steps: (i ionothermal carbonization of biomass (e.g., glucose, cellulose, lignin, and bamboo at low temperatures (150 to 180 °C in an acidic ionic liquid (IL, and (ii subsequent activation with carbon dioxide at higher temperature (500 °C. Acidic IL was used as both the medium and catalyst for advanced carbon materials production. During the first step the primary structures of spherical particles were obtained. The surfactants sodium dodecyl sulfonate (SDS, ethylene glycol (EG, and sodium oleate (SO were also used to modify the surface morphology of bio-chars and activated bio-chars. After the second step, the primary structures of bio-chars were still preserved or improved. The Brunauer-Emmett-Teller surface area and the pore diameter of activated bio-chars were 289 to 469 m2/g and 3.5 to 3.6 nm, respectively. Scanning electron microscope and transmission electron microscope images show that after modification of bio-chars with SDS, EG, and SO, activated bio-char particles agglomerated into rod-like (~200 nm diameter, nano-membrane (~70 nm thickness, and spherical (~200 nm morphologies, respectively. The morphology of activated bio-chars was easily controlled during the synthesis, which is important for the exploitation of their peculiar properties and unique applications.

  12. Mid-infrared diffuse reflectance spectroscopic examination of charred pine wood, bark, cellulose, and lignin: Implications for the quantitative determination of charcoal in soils

    Science.gov (United States)

    Reeves, J. B.; McCarty, G.W.; Rutherford, D.W.; Wershaw, R. L.

    2008-01-01

    Fires in terrestrial ecosystems produce large amounts of charcoal that persist in the environment and represent a substantial pool of sequestered carbon in soil. The objective of this research was to investigate the effect of charring on mid-infrared spectra of materials likely to be present in forest fires in order to determine the feasibility of determining charred organic matter in soils. Four materials (cellulose, lignin, pine bark, and pine wood) and char from these materials, created by charring for various durations (1 to 168 h) and at various temperatures (200 to 450 ??C), were studied. Mid-infrared spectra and measures of acidity (total acids, carboxylic acids, lactones, and phenols as determined by titration) were determined for 56 different samples (not all samples were charred at all temperatures/durations). Results showed spectral changes that varied with the material, temperature, and duration of charring. Despite the wide range of spectral changes seen with the differing materials and length/temperature of charring, partial least squares calibrations for total acids, carboxylic acids, lactones, and phenols were successfully created (coefficient of determination and root mean squared deviation of 0.970 and 0.380; 0.933 and 0.227; 0.976 and 0.120; and 0.982 and 0.101 meq/g, respectively), indicating that there is a sufficient commonality in the changes to develop calibrations without the need for unique calibrations for each specific material or condition of char formation. ?? 2008 Society for Applied Spectroscopy.

  13. SiteChar - Workflow for fit-for-purpose characterisation of CO2 storage sites in Europe

    NARCIS (Netherlands)

    Delprat-Jannaud, F.; Pearce, J.; Neele, F.; Akhurst, M.; Nielsen, C.; Mazurowski, M.; Lothe, A.; Volpi, V.; Brunsting, S.

    2014-01-01

    The FP7 SiteChar project has examined the entire site characterization chain, from the initial feasibility studies through to the final stage of application for a storage permit, on the basis of criteria defined by the relevant European legislation, highlighting important issues and recommendations

  14. Fuel, fire and heat: an experimental approach to highlight the potential of studying ash and char remains from archaelological contexts

    NARCIS (Netherlands)

    Braadbaart, F.; Poole, I.; Huisman, H.D.J.; Os, B. van

    2012-01-01

    As in traditional societies today ancient societies probably selected different fuels to meet specific heat requirements. Char and ash, the end products of fire, are often found in abundance in archaeological contexts. These end products can provide information regarding (i) the original fuel resour

  15. Are forestation, bio-char and landfilled biomass adequate offsets for the climate effects of burning fossil fuels?

    NARCIS (Netherlands)

    Reijnders, L.

    2009-01-01

    Forestation and landfilling purpose-grown biomass are not adequate offsets for the CO2 emission from burning fossil fuels. Their permanence is insufficiently guaranteed and landfilling purpose-grown biomass may even be counterproductive. As to permanence, bio-char may do better than forests or landf

  16. Effects of rice husks and their chars from hydrothermal carbonization on the germination rate and root length of Lepidium sativum

    Science.gov (United States)

    Kern, Jürgen; Mukhina, Irina; Dicke, Christiane; Lanza, Giacomo; Kalderis, Dimitrios

    2015-04-01

    Currently, char substrates gain a lot of interest, since they are being discussed as a component in growing media, which may become one option for the replacement of peat. Among different thermal conversion processes of biomass hydrothermal carbonization (HTC) has been found to produce chars with similar acidic pH values like peat. The question however is, if these hydrochars, which may contain toxic phenolic compounds are suitable to be introduced as a new substitute for peat in horticulture. In this study rice husk were hydrothermally carbonized at 200° C for 6 hours, yielding in hydrochars containing organic contaminants such as phenols and furfurals, which may affect plants and soil organisms. We investigated potential toxic effects on the germination rate and the root length of cress salad (Lepidium sativum) in four fractions: i) soil control, ii) raw rice husk + soil, iii) unwashed rice char + soil and iv) acetone/water washed rice char + soil. It could be shown that phenols and furfurals, which were removed from the hydrochar after washing by 80 to 96% did not affect the germination rate and the root length of the cress plants. The lowest germination rate and root length were found in the soil control, the highest in the non-washed hydrochar treatment, indicating a fertilization effect and growth stimulation of cress salad by hydrochar. If this result can be confirmed for other target and non-target organisms in future studies, a new strategy for the production of growing media may be developed.

  17. Adsorption of zinc ions on bone char using helical coil-packed bed columns and its mass transfer modeling

    DEFF Research Database (Denmark)

    Moreno-Pérez, J.; Bonilla-Petriciolet, A.; Rojas-Mayorga, C. K.

    2016-01-01

    char can be attributed to an ion-exchange mechanism. In summary, helical coil columns appear to be a feasible configuration for large-scale adsorption systems with high flow rates where a significant reduction on purification system size can be obtained without compromising the adsorbent performance....

  18. SYNERGISTIC EFFECTS OF NOVOLAC-BASED CHAR FORMER WITH A PHOSPHORUS/NITROGEN-CONTAINING FLAME RETARDANT IN POLYAMIDE 6

    Institute of Scientific and Technical Information of China (English)

    Wei-cheng Xiong; Li Chen; De-yi Wang; Fei Song; Yu-zhong Wang

    2012-01-01

    The synergistic effect of phosphorus oxynitride (PON) with a novolac-based char former modified by salification (NA-metal salt) on the flame retardance of polyamide 6 (PA6) was investigated.For this purpose,various flame-retardant PA6 systems were melt-compounded with PON,PON/NA,PON/NA-V2O5 and PON/NA-Fe2O3,and their flame retardance was evaluated by measuring the limiting oxygen index (LOI) values and UL-94 vertical burning ratings.The results showed that,compared with the PA6/PON/NA system,the combination of two char formers (NA-V2O5,NA-Fe2O3) with PON could obviously improve the char formation and flame retardance of PA6.The flame retardance and cone calorimetric analyses showed the stronger synergism as well as the better flame retardant performance of PON/NA-Fe2O3 flame retardant system.The effects of different char formers on the flame retardance and thermal stability of this system were also discussed.

  19. Chars from gasification of coal and pine activated with K2CO3: acetaminophen and caffeine adsorption from aqueous solutions.

    Science.gov (United States)

    Galhetas, Margarida; Mestre, Ana S; Pinto, Moisés L; Gulyurtlu, Ibrahim; Lopes, Helena; Carvalho, Ana P

    2014-11-01

    The high carbon contents and low toxicity levels of chars from coal and pine gasification provide an incentive to consider their use as precursors of porous carbons obtained by chemical activation with K2CO3. Given the chars characteristics, previous demineralization and thermal treatments were made, but no improvement on the solids properties was observed. The highest porosity development was obtained with the biomass derived char (Pi). This char sample produced porous materials with preparation yields near 50% along with high porosity development (ABET≈1500m(2)g(-1)). For calcinations at 800°C, the control of the experimental conditions allowed the preparation of samples with a micropore system formed almost exclusively by larger micropores. A mesopore network was developed only for samples calcined at 900°C. Kinetic and equilibrium acetaminophen and caffeine adsorption data, showed that the processes obey to a pseudo-second order kinetic equation and to the Langmuir model, respectively. The results of sample Pi/1:3/800/2 outperformed those of the commercial carbons. Acetaminophen adsorption process was ruled by the micropore size distribution of the carbons. The caffeine monolayer capacities suggest a very efficient packing of this molecule in samples presenting monomodal micropore size distribution. The surface chemistry seems to be the determinant factor that controls the affinity of caffeine towards the carbons.

  20. Determination of char combustion kinetics parameters: Comparison of point detector and imaging-based particle-sizing pyrometry

    Science.gov (United States)

    Schiemann, Martin; Geier, Manfred; Shaddix, Christopher R.; Vorobiev, Nikita; Scherer, Viktor

    2014-07-01

    In this study, the char burnout characteristics of two German coals (a lignite and a high-volatile bituminous coal) were investigated using two different experimental configurations and optical techniques in two distinct laboratories for measurement of temperature and size of burning particles. The optical diagnostic hardware is quite different in the two systems, but both perform two-color pyrometry and optical sizing measurements on individual particles burning in isolation from each other in high-temperature laminar flows to characterize the char consumption kinetics. The performance of the specialized systems is compared for two different combustion atmospheres (with 6.6 and 12 vol.% O2) and gas temperatures between 1700 and 1800 K. The measured particle temperatures and diameters are converted to char burning rate parameters for several residence times during the course of the particles' burnout. The results confirm that comparable results are obtained with the two configurations, although higher levels of variability in the measured data were observed in the imaging-based pyrometer setup. Corresponding uncertainties in kinetics parameters were larger, and appear to be more sensitive to systematic measurement errors when lower oxygen contents are used in the experiments. Consequently, burnout experiments in environments with sufficiently high O2 contents may be used to measure reliable char burning kinetics rates. Based on simulation results for the two coals, O2 concentrations in the range 10%-30% are recommended for kinetic rate measurements on 100 μm particles.

  1. Anadromous char as an alternate food choice to marine animals: A synthesis of Hg concentrations, population features and other influencing factors

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Marlene S., E-mail: marlene.evans@ec.gc.ca [Environment Canada, Water Science and Technology Directorate, 11 Innovation Blvd., Saskatoon SK S7N 3H5 (Canada); Muir, Derek C.G. [Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Rd., Burlington, ON L7R 4A6 (Canada); Keating, Jonathan [Environment Canada, Water Science and Technology Directorate, 11 Innovation Blvd., Saskatoon SK S7N 3H5 (Canada); Wang, Xiaowa [Environment Canada, Water Science and Technology Directorate, 867 Lakeshore Rd., Burlington, ON L7R 4A6 (Canada)

    2015-03-15

    This study was conducted to confirm sporadic measurements made over the late 1970s to the early 1990s which determined that mercury (Hg) concentrations were low in anadromous char across Arctic and subarctic Canada including northern Québec and Labrador. Over 2004–2013, anadromous char populations across northern Canada were investigated at 20 sites for Hg concentrations and life history characteristics. Hg concentrations were extremely low in anadromous char muscle, typically < 0.05 μg/g (wet weight) and, at each location, generally increased with fish length, age and nitrogen isotope (δ{sup 15}N) ratio and decreased with condition factor and %lipid; correlations with carbon isotope (δ{sup 13}C) ratio were inconsistent. Location and year were significant variables influencing Hg concentrations over the study area; longitude and latitude also were significant influencing variables. Char length, weight, age, condition factor and lipid content explained additional variance. A tendency towards higher Hg concentrations with increasing latitude may be partially related to decreasing growth of char towards the north. However, Hg concentrations in char were positively correlated with growth rates suggesting that Hg concentrations in char also were higher in the more productive study areas, including to the west where mainland riverine inputs of terrestrial carbon, nutrients, and Hg were greater. The data base for assessing time trends in char was limited by the small number of years investigated at most locations, variable fish size across years, small sample size, etc. Where temporal trends were detected, they were of increase on the long term (1970s, 1980s or early 1990s to the present) but of decrease on the short term (early 2000s to present) with Nain (Labrador) showing the converse pattern. Higher Hg concentrations were also related to lower condition factor and cooler springs. Hg concentrations in anadromous char are compared with other terrestrial, aquatic

  2. Preparation and Photocatalytic Activity of TiO2/Fine Char for Removal of Rhodamine B

    Directory of Open Access Journals (Sweden)

    Mingjie Ma

    2015-01-01

    Full Text Available TiO2/fine char (FC photocatalyst was prepared via sol-gel method with tetrabutyl titanate as the precursor and FC as the carrier. The structural property of TiO2/FC photocatalyst was investigated by X-ray diffraction (XRD and scanning electron microscopy (SEM, and the photocatalytic activity of TiO2/FC was evaluated by photocatalytic degradation of rhodamine B (RhB aqueous solution under UV light irradiation. The results showed that TiO2 was successfully coated on the surface of FC, and the TiO2/FC photocatalyst had better photocatalytic efficiency and stability for degradation of RhB under UV light illumination as compared to that of the pure TiO2 and FC. The study provided a novel way for the application of FC to the photocatalytic degradation of organic wastes.

  3. Characteristics of flame spread over the surface of charring solid combustibles at high altitude

    Institute of Scientific and Technical Information of China (English)

    LI Jie; JI Jie; ZHANG Ying; SUN JinHua

    2009-01-01

    To explore the characteristics of flame spread over the surface of charring solid combustibles at high altitude, the whitewood with uniform texture was chosen to conduct a series of experiments in Lhasa and Hefei, with altitude of 3658 m and 50 m respectively. Several parameters, including the flame height, flame spread rate, flame temperature, surface temperature, were measured on samples with different width and inclinations. A quantitative analysis of flame spread characteristics over sample surface at high altitude was performed. Results showed that, in the environment of lower pressure and oxygen concentration at high altitude, the flame height and flame spread rate over sample surface decreased, but the flame temperature increased slightly. However, with increasing of sample width, the relative difference between the flame spread rates at different altitudes decreased.

  4. Kinetic models comparison for steam gasification of coal/biomass blend chars.

    Science.gov (United States)

    Xu, Chaofen; Hu, Song; Xiang, Jun; Yang, Haiping; Sun, Lushi; Su, Sheng; Wang, Baowen; Chen, Qindong; He, Limo

    2014-11-01

    The non-isothermal thermogravimetric method (TGA) was applied to different chars produced from lignite (LN), sawdust (SD) and their blends at the different mass ratios in order to investigate their thermal reactivity under steam atmosphere. Through TGA analysis, it was determined that the most prominent interaction between sawdust and lignite occurred at the mass ratio of sawdust/lignite as 1:4, but with further dose of more sawdust into its blends with lignite, the positive interaction deteriorated due to the agglomeration and deactivation of the alkali mineral involved in sawdust at high steam gasification temperature. Through systematic comparison, it could be observed that the random pore model was the most suitable among the three gas-solid reaction models adopted in this research. Finally, rational kinetic parameters were reached from these gas-solid reaction models, which provided a basis for design and operation of the realistic system of co-gasification of lignite and sawdust in this research.

  5. Towards user-friendly spelling with an auditory brain-computer interface: the CharStreamer paradigm.

    Directory of Open Access Journals (Sweden)

    Johannes Höhne

    Full Text Available Realizing the decoding of brain signals into control commands, brain-computer interfaces (BCI aim to establish an alternative communication pathway for locked-in patients. In contrast to most visual BCI approaches which use event-related potentials (ERP of the electroencephalogram, auditory BCI systems are challenged with ERP responses, which are less class-discriminant between attended and unattended stimuli. Furthermore, these auditory approaches have more complex interfaces which imposes a substantial workload on their users. Aiming for a maximally user-friendly spelling interface, this study introduces a novel auditory paradigm: "CharStreamer". The speller can be used with an instruction as simple as "please attend to what you want to spell". The stimuli of CharStreamer comprise 30 spoken sounds of letters and actions. As each of them is represented by the sound of itself and not by an artificial substitute, it can be selected in a one-step procedure. The mental mapping effort (sound stimuli to actions is thus minimized. Usability is further accounted for by an alphabetical stimulus presentation: contrary to random presentation orders, the user can foresee the presentation time of the target letter sound. Healthy, normal hearing users (n = 10 of the CharStreamer paradigm displayed ERP responses that systematically differed between target and non-target sounds. Class-discriminant features, however, varied individually from the typical N1-P2 complex and P3 ERP components found in control conditions with random sequences. To fully exploit the sequential presentation structure of CharStreamer, novel data analysis approaches and classification methods were introduced. The results of online spelling tests showed that a competitive spelling speed can be achieved with CharStreamer. With respect to user rating, it clearly outperforms a control setup with random presentation sequences.

  6. Clean, premium-quality chars: Demineralized and carbon enriched. Final technical report, September 1, 1991--August 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T. [Southern Illinois Univ., Carbondale, IL (United States)

    1992-12-31

    The overall objective of this two-year project is to evaluate methods of preparing demineralized and carbon enriched chars from Minois Basin coal. There are two processing steps: physical cleaning of the coal and devolatilization of coal under different environments (He, H{sub 2}, He/O{sub 2}, CH{sub 4}, and CH{sub 4}/O{sub 2}) to form chars. Also, as-received and clean coal samples were mixed with hectorite, Ca-montmorillonite, and kaolinite to evaluate the potential effects of these clays on chars yield and agglomeration during devolatilization processes. Three different techniques were used: thermogravimetric analysis, differential thermogravimetric analysis, differential scanning calorimetry (DSC), and in-situ diffuse reflectance FTIR (ISDR-FTIR). Thermogravimetric measurements showed that reactive gases (except He) dissolve in the softened coal. Also, these gases convert some of the coal mineral matter into catalyst by chemical reduction and oxidation. Coal reactivity increases by adding clays because they may be catalyst for methane activation, may prevent coal agglomeration, and may modify the geometric structure of the coal surface. DSC measurements show that clean coal devolatilizes at a lower temperature than as-received sample and preoxidation lowers the devolatilization temperature. Additionally, kaolinite addition increase yields of chars from IBC-102 coal in He. In-situ diffuse reflectance FTIR experiments show that thermal decomposition of coal either increases -CH{sub 3}, content in char or alters the physical structure of -CH{sub 3}. Also, phenol groups of the coal play an important role in cross-linkage the coal structure when coal is thermally treated.

  7. Evaluation of Infrasound and Strobe Lights to Elicit Avoidance Behavior in Juvenile Salmon and Char.

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Robert, P.; Neitzel, Duane A.; Amidan, Brett G.

    1999-02-01

    Experimental tests were conducted using hatchery reared and wild juvenile chinook salmon Oncorhynchus tshawytscha, eastern brook trout Salvelinus fontinalis, and rainbow trout O. mykiss to determine specific behavior responses to infrasound (<20 Hz) and flashing strobe lights. Caged fish were acclimated in a static test tank and their behavior was recorded using low light cameras. Species specific behavior was characterized by measuring movements of the fish within the cage as well as observing startle and habituation responses. Wild chinook salmon (40-45 mm) and hatchery reared chinook salmon (45-50mm) exhibited avoidance responses when initially exposed to a 10 Hz volume displacement source. Rainbow and eastern brook trout (25-100 mm) did not respond with avoidance or other behaviors to infrasound. Habituation to the infrasound source was evident for chinook salmon during repeated exposures. Wild and hatchery chinook displayed a higher proportion of movement during the initial exposures to infrasound when the acclimation period in the test tank was 2-3 h as compared to a 12-15 h acclimation period. A flashing strobe light produced higher and more consistent movement rates in wild chinook (60% of the tests); hatchery reared chinook salmon (50%) and rainbow trout (80%). No measurable movement or other responses was observed for eastern brook trout. Little if any habituation was observed during repeated exposures to strobe lights. Results from this study indicate that consistent repeatable responses can be elicited from some fish using high intensity strobe lights under a controlled laboratory testing. The specific behaviors observed in these experiments might be used to predict how fish might react to low frequency sound and strobe lights in a screening facility. Because sub-yearling salmonids and resident species are susceptible from becoming entrained at water diversion structures we conducted tests in conjunction with our evaluation of juvenile fish screening

  8. Investigation on the catalytic effects of AAEM during steam gasification and the resultant char reactivity in oxygen using Shengli lignite at different forms

    Institute of Scientific and Technical Information of China (English)

    Jianxin Mi; Ningbo Wang; Mingfeng Wang; Pengju Huo; Dan Liu

    2015-01-01

    The purpose of this study is to investigate the catalytic effects of alkali and alkaline earth metallic species (AAEM) on char conversion during the gasification in steam and the changes in ex-situ char reactivity in oxygen after the gasification in steam using different forms (i.e. H-form, Na-form) of Shengli brown coal. The surface area, AAEM concentration and carbon crystallite of chars were obtained to understand the change in char reactivity. It was found that not only Na concentration and carbon structure were the main factors governing the char reactivity in the atmosphere of steam and oxygen, but also they interacted each other. The presence of Na could facilitate the formation of disordering carbon structure in char, and the amorphous carbon structure would in turn affect the distribution of Na and thus its catalytic performance. The surface area and pore volume had very little relationship with the char’s reactivity. Addi-tionally, the morphology of chars from different forms of coals were observed using scanning electron microscope (SEM).

  9. Quantum chemical study on the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process

    Institute of Scientific and Technical Information of China (English)

    Zheng-cheng WEN; Zhi-hua WANG; Jun-hu ZHOU; Ke-fa CEN

    2009-01-01

    Quantum chemical simulation was used to investigate the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process. Both NO-char and NO-NaYK reactions were considered as three-step processes in this calculation. Based on geometry optimizations made using the UB3LYP/6-31 G(d) method, the activation energies of NO-char and NO-Na/K reactions were calculated using the QC1SD(T)/6-3 i 1G(d, p) method; Results showed that the activation energy of the NO-Na/K reaction (107.9/82.0 kJ/mol) was much lower than that of the NO-char reaction (245.1 kJ/mol). The reactions of NaO/KO and Na2P/K2O reduced by char were also studied, and their thermodynamics were calculated using the UB3LYP/6-31G(d) method; Results showed that both Na and K can be refreshed easily and rapidly by char at high temperature during the coal rebuming process. Based on the calculations and analyses, the catalytic mechanism of Na/K on NO-char het-erogeneous reactions during the coal reburning process was clarified.

  10. Persistent organic pollutants in biota samples collected during the Ymer-80 expedition to the Arctic

    Directory of Open Access Journals (Sweden)

    Henrik Kylin

    2015-10-01

    Full Text Available During the 1980 expedition to the Arctic with the icebreaker Ymer, a number of vertebrate species were sampled for determination of persistent organic pollutants. Samples of Arctic char (Salvelinus alpinus, n=34, glaucous gull (Larus hyperboreus, n=8, common eider (Somateria mollissima, n=10, Brünnich's guillemot (Uria lomvia, n=9, ringed seal (Pusa hispida, n=2 and polar bear (Ursus maritimus, n=2 were collected. With the exception of Brünnich's guillemot, there was a marked contamination difference of birds from western as compared to eastern/northern Svalbard. Samples in the west contained a larger number of polychlorinated biphenyl (PCB congeners and also polychlorinated terphenyls, indicating local sources. Brünnich's guillemots had similar pollutant concentrations in the west and east/north; possibly younger birds were sampled in the west. In Arctic char, pollutant profiles from lake Linnévatn (n=5, the lake closest to the main economic activities in Svalbard, were similar to profiles in Arctic char from the Shetland Islands (n=5, but differed from lakes to the north and east in Svalbard (n=30. Arctic char samples had higher concentrations of hexachlorocyclohexanes (HCHs than the marine species of birds and mammals, possibly due to accumulation via snowmelt. Compared to the Baltic Sea, comparable species collected in Svalbard had lower concentrations of PCB and dichlorodiphenyltrichloroethane (DDT, but similar concentrations indicating long-range transport of hexachlorobenzene, HCHs and cyclodiene pesticides. In samples collected in Svalbard in 1971, the concentrations of PCB and DDT in Brünnich's guillemot (n=7, glaucous gull (n=2 and polar bear (n=2 were similar to the concentrations found in 1980.

  11. The role of nano-sized manganese coatings on bone char in removing arsenic(V) from solution: Implications for permeable reactive barrier technologies.

    Science.gov (United States)

    Liu, Jing; He, Lile; Dong, Faqin; Hudson-Edwards, Karen A

    2016-06-01

    Although the removal of arsenic(V) (As(V)) from solution can be improved by forming metal-bearing coatings on solid media, there has been no research to date examining the relationship between the coating and As(V) sorption performance. Manganese-coated bone char samples with varying concentrations of Mn were created to investigate the adsorption and desorption of As(V) using batch and column experiments. Breakthrough curves were obtained by fitting the Convection-Diffusion Equation (CDE), and retardation factors were used to quantify the effects of the Mn coatings on the retention of As(V). Uncoated bone char has a higher retention factor (44.7) than bone char with 0.465 mg/g of Mn (22.0), but bone char samples with between 5.02 mg/g and 14.5 mg/g Mn have significantly higher retention factors (56.8-246). The relationship between retardation factor (Y) and Mn concentration (X) is Y = 15.1 X + 19.8. Between 0.2% and 0.6% of the sorbed As is desorbed from the Mn-coated bone char at an initial pH value of 4, compared to 30% from the uncoated bone char. The ability of the Mn-coated bone char to neutralize solutions increases with increased amounts of Mn on the char. The results suggest that using Mn-coated bone char in Permeable Reactive Barriers would be an effective method for remediating As(V)-bearing solutions such as acid mine drainage.

  12. 生物质焦表面形貌SEM研究%Study on surface of biomass chars by scanning electron microscopy

    Institute of Scientific and Technical Information of China (English)

    林晓芬; 张军; 尹艳山; 盛昌栋

    2011-01-01

    The surface of biomass chars was studied using Scanning Electron Microscopy. The study shows that, the surface coarseness of biomass char is enhanced after pyrolysis, and both the special surface area and the porosity of the char increase. The surface characteristics are determined by the kinds of the biomass chars. There are hackle protuberances on the rice shell char surface, but little pores opening to the surface. There are irregular pores on the leaf char surface. Many pores on the cornstalk char surface are like honeycomb, and many pores on the cotton stalk char surface are cottony. The pyrolysis temperature has little effect on the surface characteristics of biomass chars.%采用扫描电镜对生物质焦的表面形貌进行研究.扫描电镜实验结果表明,生物质在制焦后,表面粗糙度提高,比表面积增大,孔隙更加发达.焦样表面形貌的特征主要是由生物质种类决定的,在扫描电镜下,稻壳焦样表面有锯齿状不规则的突起,但是开口在表面的孔很少:树叶焦样表面有不规则的孔:玉米杆焦样有如同蜂窝状的表面结构,表面孔十分丰富;棉花杆焦样有着絮状的表面结构,表面孔也较明显.热解温度对焦样表面形貌的影响不大.

  13. 生物质焦分形维数计算%CALCULATION OF FRACTAL DIMENSIONS OF BIOMASS CHARS

    Institute of Scientific and Technical Information of China (English)

    林晓芬; 张军; 尹艳山; 盛昌栋

    2011-01-01

    Based on the porosity structure measured by mercury porosimeter.the fractal dimensions of biomass chars have been calculated by two fractal models. The fractal dimensions based on Menger sponge model and thermodynamics are 2.7-3.1 and 2.7-2.9, respectively. The results show that the model based on thermodynamics depicts the porosity of biomass char more appropriate than the Menger sponge model. The results also show that the kinds of the biomass chars have an effect on the fractal dimensions, and totally the leaf chars have bigger fractal dimensions than the rice shell chars. The average pore diameters have an effect on the fractal dimensions. And the fractal dimensions of one biomass char decrease while the average pore diameters increase generally.%采用压汞法的实验数据,计算两种分形模型下生物质焦样的分形维数.其中根据Menger海绵模型计算得到的分形维数Dm的值在2.7~3.1之间,基于热力学关系的分形模型计算得到的分形维数Dr的值在2.7~2.9之间.分析认为第二种模型更好的描述了焦样的孔隙结构,Dr的值比Dm的值更为合理.实验结果表明,分形维数与生物质种类有关,树叶焦样的分形维数整体上大于稻壳焦样的分形维数.生物质焦样的平均孔径与分形维数有关.总的来看,同一生物质焦样的分形维数随着平均孔径的增大而减小.

  14. Removal of Methylene Blue Dye from Synthetic Wastewater with Bone Char

    Directory of Open Access Journals (Sweden)

    Gh Ghanizadeh

    2009-09-01

    Full Text Available "n "n "nBackgrounds and Objectives: Dyes  are  organic  materials  with  complex structures, toxic,  carcinogenic, teratogenic,nonbiodegredable properties and!the most!important pollutants of textile industrial wastewaters. The goal of this study was to survey the feasibility application of bone char (BC as a sorbent for the  of methylene blue (MB from synthetic wastewater.The sub goals of the research!were to determine!the adsorption isotherm, !effects of primary concentration of dye, adsorbent!dose, contact!time, and pH for the adsorption of MB with BC."nMaterials and Methods: BC was prepared under laboratory conditions by using of electrical furnace at 400°C for 2h. The prepared BC was crushed and pulverized by standard ASTM sieves with range of 10-16mesh(1.18-2mm.The  chemical composition  and  solid  structure  of BC was  analyzed using X-ray diffraction(XRD and  scanning  electronic  microscopy (SEM. Measurement  of  the surface area was carried out by N2 gas via BET isotherm and Belsorb software. The concentration of dye was measured by photometric!method (663nm."nResults: Predominant!compositionof BC is calcium hydroxyl apatite (Ca5 (PO43OH with 14m2/g surface area. The results of this study showed that increasing of primary concentration of dye, adsorbent dose and pH (5 to12 would lead to increasing of adsorption/removal of MB dye.Equilibration of dye adsorption was reached at lapse of 2h andoptimum pH for adsorption of MB with BC found in the rage of 8.5-12.Adsorption of MB witht BC complies witht freundlich isotherm(R2:0.99."nConclusion: Bone char is a cheap component that can be used as an adsorbent in water and wastewater treatment. Based on optimum pH of 8.5-12 found for the removal of MB and the fact that many of textile!industrial wastewaters have an alkaline pH, this adsorbent can be!used for the removal of dyes from these wastewaters.

  15. How do the poor handle money? What do the financial diaries of char dwellers tell us about financial inclusion?

    Directory of Open Access Journals (Sweden)

    Kuntala Lahiri-Dutt

    2013-05-01

    Full Text Available Derived from livelihoods surveys and ethnographic material about people living on the chars, or river islands, in deltaic lower Bengal, this paper illustrates the complex, diverse and ingenious ways that the poor manage money. These islands constitute some of the most vulnerable housing locations of some of the poorest communities; state services and facilities do not reach the chars because they are not listed as land in revenue records. It demonstrates that the poor live in a diverse economy where community spirit, family assistance and trust play roles equally important to markets. In doing so, it puts forth a grounded-in-the-field, evidence-based, critique of the slogan ‘financial inclusion’ that has gained prominence in recent years.

  16. Clean, premium-quality chars: Demineralized and carbon enriched. [Quarterly] technical report, March 1, 1993--May 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T.; Myszka, E. [Southern Illinois Univ., Carbondale, IL (United States)

    1993-09-01

    The overall objective of this two-year project is to evaluate methods of preparing demineralized and carbon enriched chars from Illinois Basin coals. There are two processing steps: physical cleaning of the coal and devolatilization under different environments to form chars. Two differents techniques were used, in-situ Diffuse Reflectance FTIR measurements and BTU measurements. Experiments were performed with coals IBC-101, 102, and 104 as received and after cleaning. DR-FTIR spectrums helped to explain the possible existing chemical bonds in the coal structure as well as their changes during drying and mild pyrolysis. Drying coal causes hydrogen bonds between water and coal to be broken. Liquids produced above 500{degrees}C are much higher in aromatic content, thus, effectively reducing the concentration of aliphatic groups in the overall liquid yield. BTU values of coals after methane treatment are higher than after helium treatment.

  17. Clean, premium-quality chars: Demineralized and carbon enriched. Technical report, December 1, 1992--February 28, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T.; Myszka, E. [Southern Illinois Univ., Carbondale, IL (United States); Banerjee, D. [Institute of Gas Technology, Chicago, IL (United States)

    1993-05-01

    The overall objective of this two-year project is to evaluate methods of preparing demineralized and carbon enriched chars from Illinois Basin coals. There are two processing steps: physical cleaning of the coal and devolatilization under different environments to form chars. Two different techniques were used: BET surface area analyzer and in-situ Diffuse Reflectance FTIR. Experiments were performed with coals IBC-101, 102, and 104 as received and after cleaning. It was found that the cleaning not only removes the minerals but has changed also the porous structure of the coals. DR-FTIR spectrums helped to explain the possible existing chemical bonds in the coal structure as well as their changes during drying and mild pyrolysis.

  18. Combustion of char-coal waste pellets for high efficiency and low NO{sub x}. Technical report, September 1--November 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Rajan, S. [Southern Illinois Univ., Carbondale, IL (United States)

    1994-12-31

    Illinois coals are prime candidates for use in Integrated Gasification Combined Cycle (IGCC) plants because of their high volatility and good char reactivity. In these plants, partial gasification of the coal in the presence of limestone eliminates the major portion of the sulfur species in the product gases, which are used as fuel for the topping cycle. The char produced is high in ash content, the major portion of which is calcium sulfide. It is also low in volatiles and of low density, compared to the parent coal. The economic success of the gasification route depends on the subsequent utilization of the residual char for raising steam for use in a Rankine cycle bottoming plant and/or preheating the air to the gasifier. Fluidized bed combustion of the char appears an attractive way of utilizing the char. Areas of concern in the fluidized bed combustion of the high ash, low volatility char are: attainment of high carbon conversion efficiencies; reduction of oxides of nitrogen emissions; reduction/elimination of corrosive chlorine species; reduction/elimination of sodium and other alkali species; and efficient usage of the calcium present in the ash to reduce sulfur compounds. The aim of the present project is to investigate ways of improving the carbon conversion efficiency, sulfur capture efficiency and NO{sub x} reduction during the fluidized bed combustion by pelletizing the low density char with coal and coal wastes using cornstarch or wood lignin as binder. During this first quarter, the parent coals and the chars to be tested have been analyzed. Particle size distributions have been measured. Sample pellets have been made evaluation of their properties.

  19. Pyrolysis-GC/MS of charred purified condensed tannin: towards identification of tannin-derived black carbon in environmental samples

    Science.gov (United States)

    Kaal, Joeri; Nierop, Klaas G. J.; Kraal, Peter; Preston, Caroline M.

    2010-05-01

    Tannins account for a significant proportion of plant biomass and are therefore a possible source of Black C in the charred remains from wildfires. Nonetheless, in contrast with other major biocomponents such as lignin and cellulose, the thermal degradation of tannins has not been investigated in laboratory charring experiments. We used pyrolysis-GC/MS to investigate the effects of furnace charring (30 min at fixed temperatures up to 600 °C under limited oxygen supply) on the degradation of pure condensed tannin (CT) isolated from Corsican pine (Pinus nigra) needles. The experiments showed a rapid loss (at 300 °C and higher) of the pyrogallol moieties of the B-ring of prodelphinidin-type CT, due to dehydroxylation. The relative abundance of catechols (from procyanidin-type CT) decreased at 350 °C and higher temperatures. This led to the formation of phenols that were strongly enriched between 300 and 400 °C. At higher temperatures, further dehydroxylation caused a decline in contributions of phenols producing a series of monocyclic aromatics ((alkyl)benzenes) and condensation of aromatics produced polycyclic aromatic hydrocarbons (PAHs), i.e. the typical pyrolysis fingerprint of strongly charred biomass. We conclude that (i) the thermal degradation of CT can be successfully monitored by pyrolysis-GC/MS, (ii) thermal degradation of CT is characterized by dehydroxylation of phenolic groups and condensation of aromatics that increase with temperature and (iii) CT-derived Black C may be recognized by catechol enrichments at low temperatures and possibly (relative) abundance of phenol and biphenyl at higher levels of thermal breakdown. Applying the same method to natural charcoal from gorse bushfires indicated that pyrolysis-GC/MS fingerprinting may allow for tannin identification in environmental Black C samples.

  20. Pyrolysis-GC-MS analysis of the formation and degradation stages of charred residues from lignocellulosic biomass

    OpenAIRE

    González-Vila, Francisco Javier; Tinoco, Pilar; Almendros Martín, Gonzalo; Martín Martínez, Francisco

    2001-01-01

    The structural transformations undergone by lignocellulosic biomass (freeze-dried rye grass, Lolium rigidum) subjected to progressive isothermal heating (burning at 350°C under oxidizing conditions for 30, 45, 60, 75, and 90 s) have been monitored by Curie-point pyrolysis-gas chromatographymass spectrometry (Py-GC-MS). The pyrograms suggest that even charred residues after severe heating (carbon loss ca. 50%) still contain substantial concentrations of some resistant plant structural componen...

  1. Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process.

    Directory of Open Access Journals (Sweden)

    Mariano Ucchesu

    Full Text Available The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that occurred in archaeological contexts. In addition, several carbonisation trials on modern wild and cultivated grape seeds were performed using a muffle furnace. For comparison with archaeological materials, modern grape seed samples were obtained using seven different temperatures of carbonisation ranging between 180 and 340ºC for 120 min. Analysing the grape seed size and shape by computer vision techniques, and applying the stepwise linear discriminant analysis (LDA method, discrimination of the wild from the cultivated charred grape seeds was possible. An overall correct classification of 93.3% was achieved. Applying the same statistical procedure to compare modern charred with archaeological grape seeds, found in Sardinia and dating back to the Early Bronze Age (2017-1751 2σ cal. BC, allowed 75.0% of the cases to be identified as wild grape. The proposed method proved to be a useful and effective procedure in identifying, with high accuracy, the charred grape seeds found in archaeological sites. Moreover, it may be considered valid support for advances in the knowledge and comprehension of viticulture adoption and the grape domestication process. The same methodology may also be successful when applied to other plant remains, and provide important information about the history of domesticated plants.

  2. Predictive Method for Correct Identification of Archaeological Charred Grape Seeds: Support for Advances in Knowledge of Grape Domestication Process

    Science.gov (United States)

    Ucchesu, Mariano; Orrù, Martino; Grillo, Oscar; Venora, Gianfranco; Paglietti, Giacomo; Ardu, Andrea; Bacchetta, Gianluigi

    2016-01-01

    The identification of archaeological charred grape seeds is a difficult task due to the alteration of the morphological seeds shape. In archaeobotanical studies, for the correct discrimination between Vitis vinifera subsp. sylvestris and Vitis vinifera subsp. vinifera grape seeds it is very important to understand the history and origin of the domesticated grapevine. In this work, different carbonisation experiments were carried out using a hearth to reproduce the same burning conditions that occurred in archaeological contexts. In addition, several carbonisation trials on modern wild and cultivated grape seeds were performed using a muffle furnace. For comparison with archaeological materials, modern grape seed samples were obtained using seven different temperatures of carbonisation ranging between 180 and 340ºC for 120 min. Analysing the grape seed size and shape by computer vision techniques, and applying the stepwise linear discriminant analysis (LDA) method, discrimination of the wild from the cultivated charred grape seeds was possible. An overall correct classification of 93.3% was achieved. Applying the same statistical procedure to compare modern charred with archaeological grape seeds, found in Sardinia and dating back to the Early Bronze Age (2017–1751 2σ cal. BC), allowed 75.0% of the cases to be identified as wild grape. The proposed method proved to be a useful and effective procedure in identifying, with high accuracy, the charred grape seeds found in archaeological sites. Moreover, it may be considered valid support for advances in the knowledge and comprehension of viticulture adoption and the grape domestication process. The same methodology may also be successful when applied to other plant remains, and provide important information about the history of domesticated plants. PMID:26901361

  3. Behavioural and physiological responses of brook trout Salvelinus fontinalis to midwinter flow reduction in a small ice-free mountain stream.

    Science.gov (United States)

    Krimmer, A N; Paul, A J; Hontela, A; Rasmussen, J B

    2011-09-01

    This study presents an experimental analysis of the effects of midwinter flow reduction (50-75%, reduction in discharge in 4 h daily pulses) on the physical habitat and on behaviour and physiology of overwintering brook trout Salvelinus fontinalis in a small mountain stream. Flow reduction did not result in significant lowering of temperature or formation of surface or subsurface ice. The main findings were (1) daily movement by S. fontinalis increased (c. 2·5-fold) during flow reduction, but was limited to small-scale relocations (banks were the preferred habitat and availability of these habitats was reduced during flow reduction. (3) Although both experimental and reference fish did lose mass and condition during the experiment, no effects of flow reduction on stress indicators (blood cortisol or glucose) or bioenergetics (total body fat, water content or mass loss) were detected, probably because access to the preferred type of cover remained available. Like other salmonids, S. fontinalis moves little and seeks physical cover during winter. Unlike many of the more studied salmonids, however, this species overwinters successfully in small groundwater-rich streams that often remain ice-free, and this study identifies undercut banks as the critical winter habitat rather than substratum cover.

  4. Perturbation in protein expression of the sterile salmonid hybrids between female brook trout Salvelinus fontinalis and male masu salmon Oncorhynchus masou during early spermatogenesis.

    Science.gov (United States)

    Zheng, Liang; Senda, Yoshie; Abe, Syuiti

    2013-05-01

    Most males and females of intergeneric hybrid (BM) between female brook trout (Bt) Salvelinus fontinalis and male masu salmon (Ms) Oncorhynchus masou had undeveloped gonads, with abnormal germ cell development shown by histological examination. To understand the cause of this hybrid sterility, expression profiles of testicular proteins in the BM and parental species were examined with 2-DE coupled with MALDI-TOF/TOF MS. Compared with the parental species, more than 60% of differentially expressed protein spots were down-regulated in BM. A total of 16 up-regulated and 48 down-regulated proteins were identified in BM. Up-regulated were transferrin and other somatic cell-predominant proteins, whereas down-regulated were some germ cell-specific proteins such as DEAD box RNA helicase Vasa. Other pronouncedly down-regulated proteins included tubulins and heat shock proteins that are supposed to have roles in spermatogenesis. The present findings suggest direct association of the observed perturbation in protein expression with the failure of spermatogenesis and the sterility in the examined salmonid hybrids.

  5. Differential growth in estuarine and freshwater habitats indicated by plasma IGF1 concentrations and otolith chemistry in Dolly Varden Salvelinus malma.

    Science.gov (United States)

    Bond, M H; Beckman, B R; Rohrbach, L; Quinn, T P

    2014-11-01

    This study employed a combination of otolith microchemistry to indicate the recent habitat use, and plasma concentrations of the hormone insulin-like growth factor 1 (IGF1) as an index of recent growth rate, to demonstrate differences in growth and habitat use by Dolly Varden Salvelinus malma occupying both freshwater and estuarine habitats in south-west Alaska. Extensive sampling in all habitats revealed that fish had higher IGF1 levels in estuarine compared to lake habitats throughout the summer, and that the growth rates in different habitats within the estuary varied seasonally. In addition, otolith microchemistry indicated differentiation in estuarine habitat use among individual S. malma throughout summer months. Although growth in the estuary was higher than in fresh water in nearly all sites and months, the benefits and use of the estuarine habitats varied on finer spatial scales. Therefore, this study further illustrates the diverse life histories of S. malma and indicates an evaluation of the benefits of marine waters needs to include sub-estuary scale habitat use.

  6. [Developmental abnormalities in salmonids (Salmonidae) under the conditions of large-scale volcanic pollution of their spawning ground (using dolly varden Salvelinus malma as an example)].

    Science.gov (United States)

    Esin, E V

    2015-01-01

    Rivers originating from the areas of active volcanism in Kamchatka serve a spawning ground for anadromous and resident populations of dolly varden (Salvelinus malma). In some cases, watercourses with a long-term continuous spawning of S. malma are subjected to chronic pollution with dissolved toxicants and suspended mineral particles. The revealed development conditions range from background ("clean" rivers) to critical (most "polluted" rivers). Medium pollution leads to the development of hatchlings with abnormalities in the ethmoidal head segment, lower jaw, operculum, lobes of the paired fins, and axial skeleton (up to 40% of all specimens). Delayed ossification of skeletal elements takes place. Abnormalities in the development of spinous processes occur more often (up to 49-55% compared to 25-30% in the background areas). The average number of asymmetries per specimen.(in four bilateral structures) increases from 1.1-1.4 to 1.7- 2.5. Similar developmental abnormalities have been registered in underyearlings, both anadromous and resident, influenced by various pollutant combinations. While fish continue to grow, some of them die because of abnormalities; thus, their frequency in 3-year-old specimens nears the background one. Upon extreme pollution, deviant specimens are sampled at earlier developmental stages and characterized by a lower frequency of morphological abnormalities.

  7. Sustainable development of tyre char-based activated carbons with different textural properties for value-added applications.

    Science.gov (United States)

    Hadi, Pejman; Yeung, Kit Ying; Guo, Jiaxin; Wang, Huaimin; McKay, Gordon

    2016-04-01

    This paper aims at the sustainable development of activated carbons for value-added applications from the waste tyre pyrolysis product, tyre char, in order to make pyrolysis economically favorable. Two activation process parameters, activation temperature (900, 925, 950 and 975 °C) and residence time (2, 4 and 6 h) with steam as the activating agent have been investigated. The textural properties of the produced tyre char activated carbons have been characterized by nitrogen adsorption-desorption experiments at -196 °C. The activation process has resulted in the production of mesoporous activated carbons confirmed by the existence of hysteresis loops in the N2 adsorption-desorption curves and the pore size distribution curves obtained from BJH method. The BET surface area, total pore volume and mesopore volume of the activated carbons from tyre char have been improved to 732 m(2)/g, 0.91 cm(3)/g and 0.89 cm(3)/g, respectively. It has been observed that the BET surface area, mesopore volume and total pore volume increased linearly with burnoff during activation in the range of experimental parameters studied. Thus, yield-normalized surface area, defined as the surface area of the activated carbon per gram of the precursor, has been introduced to optimize the activation conditions. Accordingly, the optimized activation conditions have been demonstrated as an activation temperature of 975 °C and an activation time of 4 h.

  8. Radiocarbon dating of charred human bone remains preserved in urns excavated from medieval Buddhist cemetery in Japan

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Toshio, E-mail: nakamura@nendai.nagoya-u.ac.j [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Sagawa, Shinichi; Yamada, Tetsuya [Gangoji Institute for Research of Cultural Properties, Nakain, Nara 630-8392 (Japan); Kanehara, Masaaki [School of Science Education, Nara University of Education, Takabatake, Nara 630-8528 (Japan); Tsuchimoto, Norio [Ichinomiya City Museum, Yamato, Ichinomiya 491-0922 (Japan); Minami, Masayo [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Omori, Takayuki [Graduate School of Environmental Studies, Nagoya University, Chikusa, Nagoya 464-8602 (Japan); Okuno, Mitsuru [Faculty of Science, Fukuoka University, Jonan, Fukuoka 814-0180 (Japan); Ohta, Tomoko [Center for Chronological Research, Nagoya University, Chikusa, Nagoya 464-8602 (Japan)

    2010-04-15

    For a preliminary test of {sup 14}C dating of cremated human remains, we have collected charred bone and wood-charcoal fragments from cremated remains contained in cinerary urns that had been excavated from medieval Buddhist cemetery at the Hoenji temple in Aichi prefecture, central Japan. More than 230 urn vessels were discovered from the excavated area of ca. 14 m wide and 14 m long. The identification of charred bone or charcoal fragments among the remains was performed by observation of surface appearance, inspection of fine structures by a microscope, bubble formation during the HCl treatments in preparing target material for AMS {sup 14}C dating, carbon and nitrogen contents, delta{sup 13}C and delta{sup 15}N values of the fragments. All {sup 14}C ages obtained for the samples that were identified as charred bone remains were almost consistent with the archeological age estimated based on typological analysis of respective urns. On the other hand, some {sup 14}C ages for the remains identified as wood charcoal, which had been produced from firewood or a wooden coffin during the cremation, were not consistent with archeological estimation, shifting toward older {sup 14}C ages, most probably as the result of old wood effect.

  9. Removal of elemental Mercury from flue gas using wheat straw chars modified by K2FeO4 reagent.

    Science.gov (United States)

    Zhou, Jianfei; Liu, Yangxian; Pan, Jianfeng

    2017-02-17

    In this article, wheat straw (WS) char, a common agricultural waste and renewable biomass, was pyrolyzed and then modified by K2FeO4 reagent to develop an efficient sorbent for removal of Hg(0) from flue gas. Brunauer-Emmett-Teller, scanning electron microscopy with energy spectrum and X-ray diffraction (XRD) were employed to characterize the sorbents. The effects of K2FeO4 loading, reaction temperature, Hg(0) inlet concentration and concentrations of gas mixtures O2, NO and SO2 in flue gas on Hg(0) removal were investigated in a fixed-bed reactor. The results show that K2FeO4-impregnation can improve pore structure of WS char and produce new active sites, which significantly enhance Hg(0) removal. Increasing Hg(0) inlet concentration significantly decreases Hg(0) removal efficiency. O2 in flue gas promotes Hg(0) oxidation by replenishing the oxygen groups on the surface of modified chars. The presence of NO obviously promotes Hg(0) removal since it can oxidize Hg(0) to Hg(NO3)2. SO2 in flue gas significantly decreases Hg(0) removal efficiency due to the competition adsorption between SO2 and Hg(0). The increase in reaction temperature has a dual impact on Hg(0) removal.

  10. Pyrolysis-GC-MS analysis of the formation and degradation stages of charred residues from lignocellulosic biomass.

    Science.gov (United States)

    González-Vila, F J; Tinoco, P; Almendros, G; Martin, F

    2001-03-01

    The structural transformations undergone by lignocellulosic biomass (freeze-dried rye grass, Lolium rigidum) subjected to progressive isothermal heating (burning at 350 degrees C under oxidizing conditions for 30, 45, 60, 75, and 90 s) have been monitored by Curie-point pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). The pyrograms suggest that even charred residues after severe heating (carbon loss ca. 50%) still contain substantial concentrations of some resistant plant structural components. Several trends were observed when monitoring the relative concentrations of the different groups of pyrolysis compounds released during successive charring stages: (i) the tetrapyrrole moiety of chlorophylls is rapidly destroyed as indicated by the decreasing yields of pyrroles and pyrrolines, whereas the phytol backbone is comparatively more resistant, leading to phytadienes after dehydration and reduction; (ii) the increasing yields of imidazoles from progressively heated samples (maximum at 45 s stage) suggest accumulation of newly formed nitrogen-containing compounds that may survive natural fires; (iii) the lignin backbone shows a relative resistance, the yields of aromatic products pointing to progressive demethoxylation; and, (iv) a selective accumulation of recalcitrant alkyl material occurred, which is interpreted as the result of thermal condensation of hydrocarbons and fatty acids into macromolecular materials in the charred residue. In terms of the intensity of the isothermal heating, the yields of the different classes of alkyl compounds follow the order phytadienes < fatty acids < alkanes < wax esters < sterols.

  11. Sorption of apolar and polar organic contaminants by waste tire rubber and its chars in single- and bi-solute systems

    Energy Technology Data Exchange (ETDEWEB)

    Lian Fei; Huang Fang; Chen Wei [College of Environmental Science and Engineering, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Nankai University, Tianjin 300071 (China); Xing Baoshan [Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003 (United States); Zhu Lingyan, E-mail: zhuly@nankai.edu.cn [College of Environmental Science and Engineering, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Nankai University, Tianjin 300071 (China)

    2011-04-15

    Single- and bi-solute sorption of organic compounds [1,3-dichlorbenzene (DCB), 1,3-dinitrobenzene (DNB) and 2,4-dichlorophenol (DCP)] on ground tire rubber and its chars was studied. The chars were prepared by pyrolyzing tire rubber at different temperatures (200-800 deg. C). Their surface area, aromaticity and hydrophobicity increase greatly with pyrolytic temperature, and the polymeric phase is partly converted into a condensed phase. The sorption of DNB and DCP increases with pyrolytic temperature and is characterized by a transition from a partition dominant to an adsorption dominant process. However, the sorption of DCB linearly decreases with the pyrolytic temperature. The enhanced adsorption of DNB and DCP on carbonized phase is primarily attributed to nonhydrophobic interactions such as {pi}-{pi} electron-donor-acceptor interactions and/or H bonding. The higher partition of DCB to polymeric phase is attributed to its high hydrophobicity. Competitive sorption between DCB and DCP on the tire chars is highly dependent on dissociation of the latter. - Research highlights: > Tire chars consist of dual sorptive domains, i.e., partition and adsorption. > High hydrophobicity of apolar organic contaminant promotes its partition into polymeric phase. > Polar aromatic contaminants show high adsorption on carbonized phase with specific interactions. > Dissociation of ionzable organic chemical heavily influences its sorption on tire chars. - The partition and adsorption of organic contaminants on waste tire chars are highly dependent on the hydrophobicity, polarity and dissociation of solutes.

  12. Estimation of surface heat flux for ablation and charring of thermal protection material

    Science.gov (United States)

    Qian, Wei-qi; He, Kai-feng; Zhou, Yu

    2016-07-01

    Ablation of the thermal protection material of the reentry hypersonic flight vehicle is a complex physical and chemical process. To estimate the surface heat flux from internal temperature measurement is much more complex than the conventional inverse heat conduction problem case. In the paper, by utilizing a two-layer pyrogeneration-plane ablation model to model the ablation and charring of the material, modifying the finite control volume method to suit for the numerical simulation of the heat conduction equation with variable-geometry, the CGM along with the associated adjoint problem is developed to estimate the surface heat flux. This estimation method is verified with a numerical example at first, the results show that the estimation method is feasible and robust. The larger is the measurement noise, the greater is the deviation of the estimated result from the exact value, and the measurement noise of ablated surface position has a significant and more direct influence on the estimated result of surface heat flux. Furthermore, the estimation method is used to analyze the experimental data of ablation of blunt Carbon-phenolic material Narmco4028 in an arc-heater. It is shown that the estimated surface heat flux agrees with the heating power value of the arc-heater, and the estimation method is basically effective and potential to treat the engineering heat conduction problem with ablation.

  13. Surface modification of bone char for removal of formaldehyde from air

    Science.gov (United States)

    Rezaee, Abbas; Rangkooy, Hosseinali; Jonidi-Jafari, Ahmad; Khavanin, Ali

    2013-12-01

    The aim of this study was to evaluate the adsorption performance of bone char (BC) modified with acetic acid for formaldehyde removal from polluted air. The porous structure, surface characteristics and functional groups involved in formaldehyde adsorption were determined using the Brunauer-Emmett-Teller (BET) method, scanning electron microscope (SEM) equipped with energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that the modified BC has a higher specific surface area than the original BC. The maximum surface area of the modified BC was 118.58 m2/g. The FTIR spectrum of modified BC indicated that the hydroxyl and carboxyl groups on the BC surface played a significant role in the adsorption of formaldehyde by modified BC. The breakthrough, equilibrium time and adsorption capacity of modified BC were greater than the original BC. Moreover, the results showed that at initial concentrations of 20, 50, 100 and 200 mg/L, the equilibrium times for BC and modified BC were 85, 75, 65 and 45 min and 95, 85, 70 and 50 min, respectively. It seems that the formaldehyde adsorption capacity of modified BC depends on both physical and chemical properties. These results showed that modified BC can be used as an efficient adsorbent for formaldehyde removal.

  14. Supercritical water gasification of Eucalyptus grandis and related pyrolysis char: Effect of feedstock composition.

    Science.gov (United States)

    Louw, Jeanne; Schwarz, Cara E; Burger, Andries J

    2016-09-01

    Eucalyptus grandis (E. grandis) wood and char products derived from pyrolysis of E. grandis wood, were gasified in supercritical water at 450°C - with and without the use of a homogeneous (K2CO3) and heterogeneous (Ni/Al2O3-SiO2) catalyst. Gas yields and gasification efficiencies were measured experimentally and compared to calculated thermodynamic equilibrium values, specifically considering the effects of the O/C ratio and volatile matter content of the feed material. Thermodynamically, feed material with lower O/C ratios (0.22) typically resulted in higher CH4 yields (30mol/kgfeed,dry) and gasification efficiencies (188%). However, experimentally, feed material with lower O/C ratios and lower volatile matter resulted in the lowest CH4 yields and gasification efficiencies. Furthermore, a linear relationship between the carbon efficiency (CE) and both the volatile matter content and O/C ratio of the feed material was found to hold true in both catalytic and non-catalytic experiments.

  15. Comparison of phosphorus recovery from incinerated sewage sludge ash (ISSA) and pyrolysed sewage sludge char (PSSC).

    Science.gov (United States)

    Kleemann, Rosanna; Chenoweth, Jonathan; Clift, Roland; Morse, Stephen; Pearce, Pete; Saroj, Devendra

    2017-02-01

    This research compares and contrasts the physical and chemical characteristics of incinerator sewage sludge ash (ISSA) and pyrolysis sewage sludge char (PSSC) for the purposes of recovering phosphorus as a P-rich fertiliser. Interest in P recovery from PSSC is likely to increase as pyrolysis is becoming viewed as a more economical method of sewage sludge thermal treatment compared to incineration. The P contents of ISSA and PSSC are 7.2-7.5% and 5.6%, respectively. Relative to the sludge, P concentrations are increased about 8-fold in ISSA, compared to roughly 3-fold in PSSC. Both PSSC and ISSA contain whitlockite, an unusual form of calcium phosphate, with PSSC containing more whitlockite than ISSA. Acid leaching experiments indicate that a liquid/solid ratio of 10 with 30min contact time is optimal to release PO4-P into leachate for both ISSA and PSSC. The proportion of P extracted from PSSC is higher due to its higher whitlockite content. Heavy metals are less soluble from PSSC because they are more strongly incorporated in the particles. The results suggest there is potential for the development of a process to recover P from PSSC.

  16. Adsorption of SO2 on bituminous coal char and activated carbon fiber

    Science.gov (United States)

    DeBarr, Joseph A.; Lizzio, Anthony A.; Daley, Michael A.

    1997-01-01

    The SO2 adsorption behaviors of activated carbons produced from Illinois coal and of commercially prepared activated carbon fibers (ACFs) were compared. There was no relation between surface area of coal-based carbons and SO2 adsorption, whereas adsorption of SO2 on the series of ACFs was inversely proportional to N2 BET surface area. Higher surface area ACFs had wider pores and adsorbed less SO2; thus, pore size distribution is thought to play a significant role in SO2 adsorption for these materials. Oxidation with HNO3 and/or H2SO4, followed by heat treatment at 700−925°C to remove carbon−oxygen complexes, resulted in increased SO2 adsorption for both coal chars and ACFs. This behavior was explained by an increase in the available number of free sites, previously occupied by oxygen and now available for SO2 adsorption. The use of nitrogen-containing functional groups on ACFs of proper pore size shows promise for further increasing SO2 adsorption capacities. Knowledge of the relationship among the number of free sites, pore size, and surface chemistry on corresponding SO2 adsorption should lead to the development of more efficient adsorbents prepared from either coal or ACFs.

  17. The SiteChar approach to efficient and focused CO2 storage site characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Neele, F.; Nepveu, M.; Hofstee, C.; Wollenweber, J. [TNO, P.O. Box 80015, NL-3508 TA Utrecht (Netherlands); Delprat-Jannaud, F.; Vincke, O.; Battani, A.; Baroni, A.; Garcia, B. [IFPEN, Rueil-Malmaison (France); Volpi, V. [OGS, Trieste (Italy); Lothe, A. [SINTEF Petroleum Research, Trondheim (Norway); Brunsting, S. [Energy research Centre of the Netherlands, ECN Policy Studies, Amsterdam (Netherlands); Pearce, J. [BGS, Nottingham (United Kingdom)

    2013-05-01

    Carbon Capture and Storage (CCS) is one of the solutions that can significantly reduce CO2 during the transition from fossil fuel-based energy to an energy system based on renewable energy sources. Recent studies point out that sufficient storage capacity in saline aquifers and depleted gas fields is available to permanently store several decades worth of current CO2 emissions. Nevertheless, a significant hurdle for the post-demonstration phase of CCS development is the lack of proven and tested storage reservoirs. One of the goals of the EU FP7 SiteChar project is to develop an efficient site characterisation workflow, to support the development of the numerous storage sites that will be needed for large-scale deployment of CCS. The workflow is designed to address all aspects of safe and secure storage required by the EU Storage Directive. The links between the Storage Directive requirements and the site characterisation workflow are described in detail. The workflow is currently being applied to five sites suitable for CCS across Europe. A final version of the workflow will be published early 2014.

  18. Surface modification of bone char for removal of formaldehyde from air

    Energy Technology Data Exchange (ETDEWEB)

    Rezaee, Abbas, E-mail: rezaee@modares.ac.ir [Environmental Health Department, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Rangkooy, Hosseinali [Environmental Health Department, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of); Occupational Health Department, Faculty of Health, Jondishapor Medical Sciences University, Ahvaz (Iran, Islamic Republic of); Jonidi-Jafari, Ahmad; Khavanin, Ali [Environmental Health Department, Faculty of Medical Sciences, Tarbiat Modares University, Tehran (Iran, Islamic Republic of)

    2013-12-01

    The aim of this study was to evaluate the adsorption performance of bone char (BC) modified with acetic acid for formaldehyde removal from polluted air. The porous structure, surface characteristics and functional groups involved in formaldehyde adsorption were determined using the Brunauer–Emmett–Teller (BET) method, scanning electron microscope (SEM) equipped with energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR), respectively. It was found that the modified BC has a higher specific surface area than the original BC. The maximum surface area of the modified BC was 118.58 m{sup 2}/g. The FTIR spectrum of modified BC indicated that the hydroxyl and carboxyl groups on the BC surface played a significant role in the adsorption of formaldehyde by modified BC. The breakthrough, equilibrium time and adsorption capacity of modified BC were greater than the original BC. Moreover, the results showed that at initial concentrations of 20, 50, 100 and 200 mg/L, the equilibrium times for BC and modified BC were 85, 75, 65 and 45 min and 95, 85, 70 and 50 min, respectively. It seems that the formaldehyde adsorption capacity of modified BC depends on both physical and chemical properties. These results showed that modified BC can be used as an efficient adsorbent for formaldehyde removal.

  19. Factors affecting biotic mercury concentrations and biomagnification through lake food webs in the Canadian high Arctic

    Energy Technology Data Exchange (ETDEWEB)

    Lescord, Gretchen L., E-mail: glescord@gmail.com [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kidd, Karen A. [University of New Brunswick/Canadian Rivers Institute, 100 Tucker Park Rd, Saint John, NB E2L 4A6 (Canada); Kirk, Jane L. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada); O' Driscoll, Nelson J. [Acadia University, 15 University Ave, Wolfville, NS B4P 2R6 (Canada); Wang, Xiaowa; Muir, Derek C.G. [Environment Canada, Aquatic Contaminants Research Division, 867 Lakeshore Rd, Burlington, ON L7S 1A1 (Canada)

    2015-03-15

    In temperate regions of Canada, mercury (Hg) concentrations in biota and the magnitude of Hg biomagnification through food webs vary between neighboring lakes and are related to water chemistry variables and physical lake features. However, few studies have examined factors affecting the variable Hg concentrations in landlocked Arctic char (Salvelinus alpinus) or the biomagnification of Hg through their food webs. We estimated the food web structure of six high Arctic lakes near Resolute Bay, Nunavut, Canada, using stable carbon (δ{sup 13}C) and nitrogen (δ{sup 15}N) isotopes and measured Hg (total Hg (THg) in char, the only fish species, and methylmercury (MeHg) in chironomids and zooplankton) concentrations in biota collected in 2010 and 2011. Across lakes, δ{sup 13}C showed that benthic carbon (chironomids) was the dominant food source for char. Regression models of log Hg versus δ{sup 15}N (of char and benthic invertebrates) showed positive and significant slopes, indicting Hg biomagnification in all lakes, and higher slopes in some lakes than others. However, no principal components (PC) generated using all water chemistry data and physical characteristics of the lakes predicted the different slopes. The PC dominated by aqueous ions was a negative predictor of MeHg concentrations in chironomids, suggesting that water chemistry affects Hg bioavailability and MeHg concentrations in these lower-trophic-level organisms. Furthermore, regression intercepts were predicted by the PCs dominated by catchment area, aqueous ions, and MeHg. Weaker relationships were also found between THg in small char or MeHg in pelagic invertebrates and the PCs dominated by catchment area, and aqueous nitrate and MeHg. Results from these high Arctic lakes suggest that Hg biomagnification differs between systems and that their physical and chemical characteristics affect Hg concentrations in lower-trophic-level biota. - Highlights: • Mercury (Hg) in Arctic char and invertebrates

  20. Different characteristics of char and soot in the atmosphere and their ratio as an indicator for source identification in Xi'an, China

    Directory of Open Access Journals (Sweden)

    Y. M. Han

    2010-01-01

    Full Text Available Numerous definitions and analytical techniques for elemental (or black carbon (EC have been published in the scientific literature, but still no generally accepted interdisciplinary definition exists. EC is not a single chemical compound, but is mainly composed of two parts of carbon contents: combustion residues from pyrolysis and combustion emissions formed via gas-to-particle conversion. Accordingly EC is subdivided into two classes: char and soot. Char is defined as carbonaceous materials obtained by heating organic substances and formed directly from pyrolysis, or as an impure form of graphitic carbon obtained as a residue when carbonaceous material is partially burned or heated with limited access of air. Soot is defined as only those carbon particles that form at high temperature via gas-phase processes. Since the different classes of EC have different chemical and physical properties, their optical light-absorbing properties differ, so that it is essential to differentiate them in the environment. The thermal optical reflectance (TOR method was used to differentiate between char-EC and soot-EC according to its stepwise thermal evolutional oxidation of different carbon fractions under different temperatures and atmosphere. Char-EC and soot-EC are operationally defined as EC1-OP and EC2+EC3 (EC1, EC2 and EC3 corresponding to carbon fractions evolved at 550, 700 and 800 °C in a 98% He/2% O2 atmosphere, respectively, respectively. One year of observations of the daily and seasonal variations of carbonaceous particles were conducted in Xi'an, China in 2004 to demonstrate the different characteristics of char and soot in the atmosphere. Total carbon (TC, organic carbon (OC, EC and char-EC showed similar seasonal trends, with high concentrations in winter and low concentrations in summer, while soot-EC revealed relatively small seasonal variations, with maximum concentration (1.85±0.72 μg m−3 in spring and minimum

  1. Behavior of mineral matters in Chinese coal ash melting during char-CO{sub 2}/H{sub 2}O gasification reaction

    Energy Technology Data Exchange (ETDEWEB)

    Xiaojiang Wu; Zhongxiao Zhang; Guilin Piao; Xiang He; Yushuang Chen; Nobusuke Kobayashi; Shigekatsu Mori; Yoshinori Itaya [University of Shanghai for Science & Technology, Shanghai (China). Department of Power Engineering

    2009-05-15

    The typical Chinese coal ash melting behavior during char-CO{sub 2}/H{sub 2}O gasification reaction was studied by using TGA, XRD, and SEM-EDX analysis. It was found that ash melting behavior during char gasification reaction is quite different from that during coal combustion process. Far from the simultaneously ash melting behavior during coal combustion, the initial melting behavior of ash usually occurs at a middle or later stage of char-CO{sub 2}/H{sub 2}O reaction because of endothermic reaction and more reactivity of char gasification reaction as compared with that of mineral melting reactions in ash. In general, the initial melting temperature of ash is as low as 200-300 K below the deformation temperature (T{sub def}) of ash with ASTM test. The initial molten parts in ash are mainly caused by iron bearing minerals such as wustite and iron-rich ferrite phases under gasification condition. Along with the proceeding of ash melting, the melting behavior appears to be accelerated by the presence of calcium to form eutectic mixtures in the FeO-SiO{sub 2}-Al{sub 2}O{sub 3} and CaO-SiO{sub 2}-Al{sub 2}O{sub 3} system. The different states of iron are the dominant reason for different melting behaviors under gasification and combustion conditions. Even under both reducing conditions, the ash fusion temperature (AFT) of coal under char-CO{sub 2} reaction is about 50-100 K lower than that under char-H{sub 2}O reaction condition. The main reason of that is the higher content of CO under char-CO{sub 2} reaction, which can get a lower ratio of Fe{sup 3+}/{Sigma}Fe in NaO-Al{sub 2}O{sub 3}-SiO{sub 2}-FeO melts. 38 refs., 8 figs., 4 tabs.

  2. Performance prediction and validation of equilibrium modeling for gasification of cashew nut shell char

    Directory of Open Access Journals (Sweden)

    M. Venkata Ramanan

    2008-09-01

    Full Text Available Cashew nut shell, a waste product obtained during deshelling of cashew kernels, had in the past been deemed unfit as a fuel for gasification owing to its high occluded oil content. The oil, a source of natural phenol, oozes upon gasification, thereby clogging the gasifier throat, downstream equipment and associated utilities with oil, resulting in ineffective gasification and premature failure of utilities due to its corrosive characteristics. To overcome this drawback, the cashew shells were de-oiled by charring in closed chambers and were subsequently gasified in an autothermal downdraft gasifier. Equilibrium modeling was carried out to predict the producer gas composition under varying performance influencing parameters, viz., equivalence ratio (ER, reaction temperature (RT and moisture content (MC. The results were compared with the experimental output and are presented in this paper. The model is quite satisfactory with the experimental outcome at the ER applicable to gasification systems, i.e., 0.15 to 0.30. The results show that the mole fraction of (i H2, CO and CH4 decreases while (N2 + H2O and CO2 increases with ER, (ii H2 and CO increases while CH4, (N2 + H2O and CO2 decreases with reaction temperature, (iii H2, CH4, CO2 and (N2 + H2O increases while CO decreases with moisture content. However at an equivalence ratio less than 0.15, the model predicts an unrealistic composition and is observed to be non valid below this ER.

  3. Linking Pyrogenic Organic Matter Reactivity in Soil to its Charring Temperature and Wood Source

    Science.gov (United States)

    Filley, T. R.; Gibson, C. D.; Hatton, P. J.; Dastmalchi, K.; Chatterjee, S.; Nadelhoffer, K. J.; Stark, R. E.; Bird, J.

    2014-12-01

    Understanding the link between the chemical and structural properties of pyrogenic organic matter (PyOM) and its subsequent reactivity in soil is critical to predict how future increases in forest fire frequency and intensity will affect C and N cycling. Herein, we present results from a laboratory incubation that investigated the effects of wood species and charring temperature on the decomposition of PyOM and native soil organic carbon (SOC) dynamics in a sandy soil from a northern temperate forest (University of Michigan Biological Station, Pellston, MI, USA). PyOM was produced from highly 13C/15N-labeled red maple (RM; Acer rubrum) and jack pine (JP; Pinus banksania) at 0 (native wood), 200, 300, 450 and 600 °C. PyOM amendments to soil were at 11 % total soil C. After 3 months of this ongoing incubation, 13CO2 evolution indicates that both pyrolysis temperature and species played a significant role in PyOM and native SOC mineralization. For both species, PyOM-C mineralization decreased with increasing temperature and PyOM ≥200 °C additions decreased SOC mineralization relative to controls.. In addition, PyOM-C mineralization of RM-derived PyOM was enhanced relative to JP-derived PyOM at temperatures Soils with added RM-derived PyOM exhibited significantly lower SOC mineralization at 300 and 450 °C than from JP-derived PyOM additions. These results highlighting interactive temperature and species effects are consistent with our detailed spectroscopic, elemental and isotope analysis of the PyOM samples across this pyrolysis gradient, which shows significant physicochemical changes at 300 °C for JP and between 300 and 450 °C for RM. Efforts will be made in this paper to link PyOM structural and chemical properties to the PyOM and native SOC turnover rates.

  4. Assessing the impacts of river regulation on native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats in the upper Flathead River, Montana, USA

    Science.gov (United States)

    Muhlfeld, Clint C.; Jones, Leslie A.; Kotter, D.; Miller, William J.; Geise, Doran; Tohtz, Joel; Marotz, Brian

    2012-01-01

    Hungry Horse Dam on the South Fork Flathead River, Montana, USA, has modified the natural flow regimen for power generation, flood risk management and flow augmentation for anadromous fish recovery in the Columbia River. Concern over the detrimental effects of dam operations on native resident fishes prompted research to quantify the impacts of alternative flow management strategies on threatened bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats. Seasonal and life‐stage specific habitat suitability criteria were combined with a two‐dimensional hydrodynamic habitat model to assess discharge effects on usable habitats. Telemetry data used to construct seasonal habitat suitability curves revealed that subadult (fish that emigrated from natal streams to the river system) bull trout move to shallow, low‐velocity shoreline areas at night, which are most sensitive to flow fluctuations. Habitat time series analyses comparing the natural flow regimen (predam, 1929–1952) with five postdam flow management strategies (1953–2008) show that the natural flow conditions optimize the critical bull trout habitats and that the current strategy best resembles the natural flow conditions of all postdam periods. Late summer flow augmentation for anadromous fish recovery, however, produces higher discharges than predam conditions, which reduces the availability of usable habitat during this critical growing season. Our results suggest that past flow management policies that created sporadic streamflow fluctuations were likely detrimental to resident salmonids and that natural flow management strategies will likely improve the chances of protecting key ecosystem processes and help to maintain and restore threatened bull trout and westslope cutthroat trout populations in the upper Columbia River Basin.

  5. Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams. Final Report 1992.

    Energy Technology Data Exchange (ETDEWEB)

    Underwood, Keith D.

    1995-01-01

    The goal of this two year study was to determine if supplementation with hatchery reared steelhead trout (Oncorhynchus mykiss) and spring chinook salmon (O. tshawytscha) negatively impacted wild native bull trout (Salvelinus confluentus) through competitive interactions. Four streams with varying levels of fish supplementation activity were sampled in Southeast Washington. Tasks performed during this study were population density, relative abundance, microhabitat utilization, habitat availability, diet analysis, bull trout spawning ground surveys, radio telemetry of adult bull trout, and growth analysis. Results indicate that bull trout overlapped geographically with the supplemented species in each of the study streams suggesting competition among species was possible. Within a stream, bull trout and the supplemented species utilized dissimilar microhabitats and microhabitat utilization by each species was the same among streams suggesting that there was no shifts in microhabitat utilization among streams. The diet of bull trout and O. mykiss significantly overlapped in each of the study streams. The stream most intensely supplemented contained bull trout with the slowest growth and the non-supplemented stream contained bull trout with the fastest growth. Conversely, the stream most intensely supplemented contain steelhead with the fastest growth and the non-supplemented stream contained steelhead with the slowest growth. Growth indicated that bull trout may have been negatively impacted from supplementation, although other factors may have contributed. At current population levels, and current habitat quantity and quality, no impacts to bull trout as a result of supplementation with hatchery reared steelhead trout and spring chinook salmon were detected. Project limitations and future research recommendations are discussed.

  6. Assessing the influence of migration barriers and feeding ecology on total mercury concentrations in Dolly Varden (Salvelinus malma) from a glaciated and non-glaciated stream.

    Science.gov (United States)

    Cyr, Andrew; Sergeant, Christopher J; Lopez, Juan Andres; O'Hara, Todd

    2017-02-15

    Assimilation of mercury (Hg) into food webs is directly influenced by ecological factors such as local habitat characteristics, species feeding behavior, and movement patterns. Total Hg concentrations ([THg]) in biota from Subarctic latitudes are driven both by broad spatial processes such as long-range atmospheric transport and more local influences such as biovectors and geology. Thus, even relatively pristine protected lands such as national parks are experiencing Hg accumulation. We analyzed [THg] and stable isotopes of carbon (δ(13)C) and nitrogen (δ(15)N) in 104 Dolly Varden (Salvelinus malma) collected from two rivers in southeastern Alaska, upstream and downstream of apparent anadromous migration barriers in watersheds with and without glacial coverage. To assess the potential magnitude of marine-derived THg returning to freshwater, we analyzed [THg] in ten adult pink salmon from each study system. There were no differences in Dolly Varden mean [THg] between sites after the data were standardized for fork length, but unadjusted [THg] varied relative to fish size and δ(15)N values. While previous studies generally show that [THg] increases with higher δ(15)N values, we found that Dolly Varden below migration barriers and foraging on salmon eggs had the highest δ(15)N values among all sampled individuals, but the lowest [THg]. Dolly Varden residing below anadromous barriers had δ(13)C values consistent with marine influence. Since salmon eggs typically have low [Hg], our results suggest that abundant salmon populations and the dietary subsidy they provide may reduce the annual exposure to [Hg] in egg-eating stream fishes such as Dolly Varden. In addition to identifying a suitable species for freshwater Hg monitoring in southeastern Alaska, our study more broadly implies that river characteristics, location within a river, fish size, and feeding ecology are important factors influencing Hg accumulation.

  7. The effects of total dissolved solids on egg fertilization and water hardening in two salmonids--Arctic Grayling (Thymallus arcticus) and Dolly Varden (Salvelinus malma).

    Science.gov (United States)

    Brix, Kevin V; Gerdes, Robert; Curry, Nathan; Kasper, Amanda; Grosell, Martin

    2010-04-15

    Previous studies have indicated that salmonid fertilization success may be very sensitive to elevated concentrations of total dissolved solids (TDS) with effects at concentrations as low as 250mgl(-1) being reported. However, interpretation of these studies is complicated by poor control performance and variable concentration response relationships. To address this, a series of experiments were performed to evaluate TDS effects on Arctic Grayling (Thymallus arcticus) and Dolly Varden (Salvelinus malma) fertilization success and identify possible mechanisms for previously observed test variability and any observed effects of TDS. Results indicate that some of the experiments reported here were likely confounded by extended milt holding times prior to experiment initiation. Milt holding times >6h were shown to significantly reduce control fertilization and corresponding concentration response relationships were variable. When milt holding time was minimized during fertilization experiments, consistent control performance with >90% control fertilization was achieved and consistent concentration response relationships were observed for both species examined. Experiments performed under these conditions indicate that Arctic Grayling and Dolly Varden fertilization success is not sensitive to elevated TDS with EC20s (concentration causing 20% effect) of >2782 and >1817mgl(-1) (the highest concentrations tested), respectively. However, TDS was shown to significantly affect embryo water absorption during the water hardening phase immediately following fertilization. The lowest observable effect concentrations (LOECs) for this endpoint were 1402 and 964mgl(-1) for Arctic Grayling and Dolly Varden, respectively. The effect of reduced embryo turgidity, due to impaired water absorption, on resistance to mechanical damage under real world conditions needs further investigation in order to understand the implications of this observed effect.

  8. An ecological risk assessment of the acute and chronic toxicity of the herbicide picloram to the threatened bull trout (salvelinus confluentus) and the rainbow trout (onchorhyncus mykiss)

    Science.gov (United States)

    Fairchild, J.F.; Feltz, K.P.; Sappington, L.C.; Allert, A.L.; Nelson, K.J.; Valle, J.

    2009-01-01

    We conducted acute and chronic toxicity studies of the effects of picloram acid on the threatened bull trout (Salvelinus confluentus) and the standard coldwater surrogate rainbow trout (Oncorhynchus mykiss). Juvenile fish were chronically exposed for 30 days in a proportional flow-through diluter to measured concentrations of 0, 0.30, 0.60, 1.18, 2.37, and 4.75 mg/L picloram. No mortality of either species was observed at the highest concentration. Bull trout were twofold more sensitive to picloram (30-day maximum acceptable toxic concentration of 0.80 mg/L) compared to rainbow trout (30-day maximum acceptable toxic concentration of 1.67 mg/L) based on the endpoint of growth. Picloram was acutely toxic to rainbow trout at 36 mg/L (96-h ALC50). The acute:chronic ratio for rainbow trout exposed to picloram was 22. The chronic toxicity of picloram was compared to modeled and measured environmental exposure concentrations (EECs) using a four-tiered system. The Tier 1, worst-case exposure estimate, based on a direct application of the current maximum use rate (1.1 kg/ha picloram) to a standardized aquatic ecosystem (water body of 1-ha area and 1-m depth), resulted in an EEC of 0.73 mg/L picloram and chronic risk quotients of 0.91 and 0.44 for bull trout and rainbow trout, respectively. Higher-tiered exposure estimates reduced chronic risk quotients 10-fold. Results of this study indicate that picloram, if properly applied according to the manufacturer's label, poses little risk to the threatened bull trout or rainbow trout in northwestern rangeland environments on either an acute or a chronic basis. ?? 2008 Springer Science+Business Media, LLC.

  9. Study on Char Forming Properties of ABS Flame Retarded by EG%可膨胀石墨阻燃ABS分解成炭性能研究

    Institute of Scientific and Technical Information of China (English)

    王志伟; 李荣勋; 周兵; 刘光烨

    2011-01-01

    The char forming properties of EG were studied by observing its macrostructure and microstructure. The thermogravimetric processes of EG and ABS/EG were studied by TG. The microstructure of flame-retardant ABS/EG was studied by SEM. The results show that EG has special "worm" structure after expansion, which imparts size effect and load effect to char layer of EG; flame-retardant ABS/EG can form compact and high temperature resistant char layer,which has heat insulation effect and oxygen insulation effect; the porous char layer structure can improve the structure stability of flame-retardant ABS/EG; the load catalyzing effect of EG char layer accelerates thermo-oxidation degradation and char crosslinking formation of ABS,meanwhile the char layer of EG can protect the char products of ABS, so it can increase the practical amount of char residue.%通过观测可膨胀石墨(EG)的宏观和微观结构,探讨了EG的分解成炭性能,利用热失重分析仪研究了EG与EG阻燃ABS的热失重行为,并采用扫描电镜观察了EG阻燃ABS膨胀炭层的微观结构.结果表明:EG自身膨胀后具有独特的"蠕虫"状结构,使EG炭层具有尺寸效应和负载作用;EG阻燃ABS形成了致密,耐高温的膨胀炭层,发挥隔氧、隔热作用,并且炭层呈现多孔的发泡堆砌结构,结构稳定性提高;EG膨胀炭层的负载值化作用促进了ABS的热氧降解反应和交联成炭反应,同时EG炭层能够保护ABS成炭产物,提高实际残炭量.

  10. Integrated production/use of ultra low-ash coal, premium liquids and clean char. [Quarterly] technical report, March 1, 1993--May 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, C.W.; Carlson, S.L. [Illinois State Geological Survey, Champaign, IL (United States); Fatemi, M. [Amoco Research Center, Naperville, IL (United States); Snoeyink, V.L.; Feizoulof, C.A. [Illinois Univ., Urbana, IL (United States); Klavetter, E. [Sandia National Labs., Albuquerque, NM (United States)

    1993-09-01

    Tests this quarter showed the adsorption efficiency of an oxidized activated ChemCoal{trademark} (OACC) char for removing volatile organic compounds (VOCs) from spiked water is higher than for unoxidized activated char (ACC). OACC destroyed (or reacted with) a higher percentage of VOCs when loaded char was heated quickly to 850{degrees}C. This was expected based on the OACC`s superiority as an elimination catalyst. Aromatic VOCs appeared to be adsorbed on the chars more readily than the chlorinated ones but the multichlorinated VOCs appeared to be adsorbed more strongly. The performance of two oxidized carbons (OST3-9 and OACC chars) for the removal of the VOCs from two industrial waste waters spiked with VOCs appeared similar. The more active catalyst, OST3-9 appeared more effective than OACC in destroying the adsorbed materials. A series of carbons having differing levels of oxygen on the surface was prepared by desorbing oxygen from the surface placed there by nitric acid oxidation. Tests revealed that the capacity to adsorb 2-nitrophenol increased as the outgassing temperature was increased. This indicates that PNP adsorption is increased as surface oxygen is removed from the carbon.

  11. Utilization of CO2 and biomass char derived from pyrolysis of Dunaliella salina: the effects of steam and catalyst on CO and H2 gas production.

    Science.gov (United States)

    Yang, Chao; Jia, Lishan; Su, Shuai; Tian, Zhongbiao; Song, Qianqian; Fang, Weiping; Chen, Changping; Liu, Guangfa

    2012-04-01

    Biomass char, by-product of Dunaliella salina pyrolysis at a final pyrolysis temperature of 500°C, was used as feedstock material in this study. The reactions of biomass char with CO(2) were performed in a fixed-bed reactor to evaluate the effect of temperature and steam on the CO(2) conversion, CO yield and gas composition. The CO(2) conversion and CO yield without steam and catalyst reached about 61.84% and 0.99mol/(mol CO(2)) at 800°C, respectively. Steam and high temperature led to high CO(2) conversion. A new approach for improving H(2) was carried out by using biomass char and Au/Al(2)O(3) catalyst, which combined steam gasification of biomass char and water gas shift reaction, and the H(2) concentration was 1.8 times higher than without catalyst. The process not only mitigated CO(2) emission and made use of residual biomass char, but also created renewable source.

  12. The Research Status on Preparation and Application of Biomass Activated Char%生物质活性半焦制备及应用研究现状

    Institute of Scientific and Technical Information of China (English)

    周卫红; 白斌; 李兰兰; 徐安壮

    2015-01-01

    该文分析了生物半焦制备过程中热解温度、热解速率等条件对生物半焦吸附性能的影响。结果表明随热解温度升高,比表面积及孔隙结构呈现先增大后减小趋势,快速热解获得比慢速热解更好孔隙结构。通过活化和脱灰方式对半焦进行改性,改性后的半焦具有更好的吸附性能,也称为活性半焦。生物质活性半焦用于处理染料废水和烟气脱汞等。%The effects of pyrolysis temperature, pyrolysis rate and other conditions on the activity of biomass char in the process of biomass char preparation were analyzed. The results showed that surface area and pore structure firstly increased and then decreased with the increase of the pyrolysis temperature. The pore structure was better under quickly pyrolysis than slowly pyrolysis. Biomass char can have the better adsorbability by modified and deashing that was called activated char. Biomass activated char were applied on dye wastewater treatment and flue gas demercuration.

  13. Structural features of resorcinol-formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics

    Science.gov (United States)

    Gun'ko, Vladimir M.; Bogatyrov, Viktor M.; Turov, Vladimir V.; Leboda, Roman; Skubiszewska-Zięba, Jadwiga; Urubkov, Iliya V.

    2013-10-01

    Products of resorcinol-formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (Cw = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if Cw = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp3 C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.

  14. Structural features of resorcinol–formaldehyde resin chars and interfacial behavior of water co-adsorbed with low-molecular weight organics

    Energy Technology Data Exchange (ETDEWEB)

    Gun’ko, Vladimir M., E-mail: vlad_gunko@ukr.net [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Bogatyrov, Viktor M.; Turov, Vladimir V. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, 03164 Kyiv (Ukraine); Leboda, Roman; Skubiszewska-Zięba, Jadwiga [Faculty of Chemistry, Maria Curie-Skłodowska University, 20031 Lublin (Poland); Urubkov, Iliya V. [Kurdyumov Institute of Metal Physics, 36 Vernadsky Boulevard, 03142 Kyiv (Ukraine)

    2013-10-15

    Products of resorcinol–formaldehyde resin carbonization (chars) are characterized by different morphology (particle shape and sizes) and texture (specific surface area, pore volume and pore size distribution) depending on water content during resin polymerization. At a low amount of water (C{sub w} = 37.8 wt.%) during synthesis resulting in strongly cross-linked polymers, carbonization gives nonporous particles. An increase in the water content to 62.7 wt.% results in a nano/mesoporous char, but if C{sub w} = 73.3 wt.%, a char is purely nanoporous. Despite these textural differences, the Raman spectra of all the chars are similar because of the similarity in the structure of their carbon sheets with a significant contribution of sp{sup 3} C atoms. However, the difference in the spatial organization of the carbon sheet stacks in the particles results in the significant differences in the textural and morphological characteristics and in the adsorption properties of chars with respect to water, methane, benzene, hydrogen, methylene chloride, and dimethylsulfoxide.

  15. Pyrolysis of waste animal fats in a fixed-bed reactor: Production and characterization of bio-oil and bio-char

    Energy Technology Data Exchange (ETDEWEB)

    Ben Hassen-Trabelsi, A., E-mail: aidabenhassen@yahoo.fr [Centre de Recherche et de Technologies de l’Energie (CRTEn), Technopôle Borj-Cédria, B.P 95, 2050, Hammam Lif (Tunisia); Kraiem, T. [Centre de Recherche et de Technologies de l’Energie (CRTEn), Technopôle Borj-Cédria, B.P 95, 2050, Hammam Lif (Tunisia); Département de Géologie, Université de Tunis, 2092, Tunis (Tunisia); Naoui, S. [Centre de Recherche et de Technologies de l’Energie (CRTEn), Technopôle Borj-Cédria, B.P 95, 2050, Hammam Lif (Tunisia); Belayouni, H. [Département de Géologie, Université de Tunis, 2092, Tunis (Tunisia)

    2014-01-15

    Highlights: • Produced bio-fuels (bio-oil and bio-char) from some animal fatty wastes. • Investigated the effects of main parameters on pyrolysis products distribution. • Determined the suitable conditions for the production of the maximum of bio-oil. • Characterized bio-oils and bio-chars obtained from several animal fatty wastes. - Abstract: Several animal (lamb, poultry and swine) fatty wastes were pyrolyzed under nitrogen, in a laboratory scale fixed-bed reactor and the main products (liquid bio-oil, solid bio-char and syngas) were obtained. The purpose of this study is to produce and characterize bio-oil and bio-char obtained from pyrolysis of animal fatty wastes. The maximum production of bio-oil was achieved at a pyrolysis temperature of 500 °C and a heating rate of 5 °C/min. The chemical (GC–MS analyses) and spectroscopic analyses (FTIR analyses) of bio-oil showed that it is a complex mixture consisting of different classes of organic compounds, i.e., hydrocarbons (alkanes, alkenes, cyclic compounds…etc.), carboxylic acids, aldehydes, ketones, esters,…etc. According to fuel properties, produced bio-oils showed good properties, suitable for its use as an engine fuel or as a potential source for synthetic fuels and chemical feedstock. Obtained bio-chars had low carbon content and high ash content which make them unattractive for as renewable source energy.

  16. Intensification of adsorption process by using the pyrolytic char from waste tires to remove chromium(Ⅵ) from wastewater

    Institute of Scientific and Technical Information of China (English)

    ZHOU Jie; YANG Yong-rong

    2004-01-01

    Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char(PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr(Ⅵ) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution / concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon(CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C-OH, C=O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(Ⅵ) ion are weaker than that of CAC, which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr(Ⅵ) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr(Ⅵ) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr(Ⅵ) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr(Ⅵ) removal. The adsorption of Cr(Ⅵ) has been identified as pseudo-second- order kinetics. The rate constants of adsorption have been evaluated.

  17. Potential of aeration flow rate and bio-char addition to reduce greenhouse gas and ammonia emissions during manure composting.

    Science.gov (United States)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-02-01

    Aeration is an important factor influencing CO2, CH4, N2O and NH3 emissions from the composting process. Both CH4 and N2O are potent greenhouse gases (GHG) of high importance. Here, we examined the effects of high and low aeration rates together with addition of barley straw with and without bio-char on GHG and NH3 emissions from composting cattle slurry and hen manure in small-scale laboratory composters. Depending on treatment, cumulative C losses via CO2 and CH4 emissions accounted for 11.4-22.5% and 0.004-0.2% of initial total carbon, while N losses as N2O and NH3 emissions comprised 0.05-0.1% and 0.8-26.5% of initial total nitrogen, respectively. Decreasing the flow rate reduced cumulative NH3 losses non-significantly (by 88%) but significantly increased CH4 losses (by 51%) from composting of cattle slurry with barley straw. Among the hen manure treatments evaluated, bio-char addition to composting hen manure and barley straw at low flow rates proved most effective in reducing cumulative NH3 and CH4 losses. Addition of bio-char in combination with barley straw to hen manure at both high and low flow rates reduced total GHG emissions (as CO2-equivalents) by 27-32% compared with barley straw addition alone. Comparisons of flow rates showed that low flow could be an alternative strategy for reducing NH3 losses without any significant change in N2O emissions, pointing to the need for well-controlled composting conditions if gaseous emissions are to be minimised.

  18. Intensification of adsorption process by using the pyrolytic char from waste tires to remove chromium (VI) from wastewater.

    Science.gov (United States)

    Zhou, Jie; Yang, Yong-Rong

    2004-01-01

    Pyrolysis has the potential of transforming waste into valuable recyclable products. Pyrolytic char (PC) is one of the most important products from the pyrolysis of used tires. One of the most significant applications for pyrolytic char recovered is used for the removal of Cr(VI) in the wastewater effluent to control waste by waste. The surface chemistry properties of surface element distribution/concentration and chemical structure were examined for the pyrolytic char and the commercial activated carbon (CAC) respectively. The results showed that surfaces of PC possesses a large amount of ester and hydrocarbon graft, whereas there are mainly carbon functional components of C-OH, C=O and COOH on the surface of CAC. Therefore the surface electronegativity of PC is lower than that of CAC in the water. The repulsive interactions between the surfaces of PC and the negatively charged Cr(VI) ion are weaker than that of CAC, which results in an intensification of the adsorption process by the utilization of PC. The adsorption isotherms of Cr(VI) ion on the two kinds of carbons were determined experimentally. The larger adsorption amount on the PC in the case of Cr(VI) may be attributed mainly to its special surface micro-chemical environment. The mechanism of the removal Cr(VI) from aqueous solution was assumed to be the integration of adsorption and redox reaction. The adsorption was the rate-controlled step for Cr(VI) removal. The adsorption of Cr(VI) was identified as pseudo-second-order kinetics. The rate constants of adsorption were evaluated.

  19. Impact of charring on cereal grain characteristics: linking prehistoric manuring practice to 15N signatures in archaeobotanical material

    DEFF Research Database (Denmark)

    Kanstrup, Marie; Thomsen, Ingrid Kaag; Mikkelsen, Peter Hambro;

    2012-01-01

    . However, despite attempts to deliberately tamper and distort the grain δ15N signature, the changes observed in this study were too small to be of any consequences for the archaeobotanical applicability of the method. Thus the isotope method offers unique evidence about prehistoric manuring practice....... in either a systematic or substantial way and conclude that manuring most likely will be detectable in archaeobotanical charred grains. As certain within-grain variability in δ15N existed, especially in the intensively manured grains, the resolution of this kind of information should be carefully considered...

  20. Effect of coal rank and mineral matter on gasification reactivity of coal char treated at high temperature; Netsushorishita sekitan char no gas ka tokusei ni taisuru tanshu oyobi kobutsushitsu no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, K.; Takei, H.; Harano, A.; Takarada, T. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    In the wide range from brown coal to anthracite, an investigation was made of effects of heat treatment on physical/chemical properties and of coal rank dependence. For the experiment, 12 kinds of coal samples were used, and for heat treatment, the fluidized bed heated by the electric furnace and the infrared-ray gold image furnace were used. To examine characteristics of the heat-treated coal char, conducted were oxygen gasification, TPD measurement, XRD measurement, alkali metal measurement, and pore distribution measurement. The following were obtained from the experiment. The gasification reaction rate of the char heat-treated in the temperature range between 900{degree}C to 1700{degree}C decreases with a rise of the temperature of heat treatment, and the degree of decrease in the rate depends on coal rank. The order of gasification rate between coal ranks depends on the temperature of heat treatment, and the lower the heat treatment temperature is, the more largely the gasification rate is influenced by catalysis of mineral matters included in the coal. As causes of the decrease in gasification rate associated with the rise in temperature of heat treatment, indicated were release of alkali metal having catalysis and decrease of active sites by carbonaceous crystallinity. 6 figs.

  1. Study on product distributions and char morphology during rapid co-pyrolysis of platanus wood and lignite in a drop tube fixed-bed reactor.

    Science.gov (United States)

    Meng, Haiyu; Wang, Shuzhong; Chen, Lin; Wu, Zhiqiang; Zhao, Jun

    2016-06-01

    The rapid co-pyrolytic behavior of platanus wood and Pingzhuang lignite was explored in a drop tube fixed-bed reactor under nitrogen atmosphere. Synergistic effects were evaluated using the deviations between experimental and predicted values of product yields and gas components. Surface morphology of residual chars were also investigated applying the scanning electron microscopy technique (SEM). This study found that the experimental values of gas volume yields were greater than the predicted, and the maximum gas volume yield exhibited with 50% biomass blending ratio at 1000°C. Positive or negative synergistic effects happened in gas components at different blending ratios and temperatures. The SEM results indicated that the differences of char surface morphology were evident. The fractal dimensions of residual chars increased with increasing biomass blending ratio, which may improve their gasification or combustion reactivity. The change in product yields and gas components was attributed to the secondary reactions and tar cracking.

  2. Coal combustion science: Task 1, Coal char combustion: Task 2, Fate of mineral matter. Quarterly progress report, July--September 1993

    Energy Technology Data Exchange (ETDEWEB)

    Hardesty, D.R. [ed.; Hurt, R.H.; Davis, K.A.; Baxter, L.L.

    1994-07-01

    Progress reports are presented for the following tasks: (1) kinetics and mechanisms of pulverized coal char combustion and (2) fate of inorganic material during coal combustion. The objective of Task 1 is to characterize the combustion behavior of selected US coals under conditions relevant to industrial pulverized coal-fired furnaces. In Sandia`s Coal Combustion Laboratory (CCL), optical techniques are used to obtain high-resolution images of individual burning coal char particles and to measure, in situ, their temperatures, sizes, and velocities. Detailed models of combustion transport processes are then used to determine kinetic parameters describing the combustion behavior as a function of coal type and combustion environment. Partially reacted char particles are also sampled and characterized with advanced materials diagnostics to understand the critical physical and chemical transformations that influence reaction rates and burnout times. The ultimate goal of the task is the establishment of a data base of the high temperature reactivities of chars from strategic US coals, from which important trends may be identified and predictive capabilities developed. The overall objectives for task 2 are: (1) to complete experimental and theoretical investigation of ash release mechanisms; (2) to complete experimental work on char fragmentation; (3) to establish the extent of coal (as opposed to char) fragmentation as a function of coal type and particle size; (4) to develop diagnostic capabilities for in situ, real-time, qualitative indications of surface species composition during ash deposition, with work continuing into FY94; (5) to develop diagnostic capabilities for in situ, real-time qualitative detection of inorganic vapor concentrations; and (6) to conduct a literature survey on the current state of understanding of ash deposition, with work continuing into FY94.

  3. 生物质快速热裂解炭的分析及活化研究%Characterization and Activation of Pyrolytic Char from Fast Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    尹倩倩; 王树荣

    2013-01-01

    采用化学(KOH)方法对两种具有代表性的生物质原料(花梨木和稻壳)的快速热裂解固体产物-热解炭进行了活化,并采用氮吸附、X射线衍射(XRD)、傅里叶红外光谱分析(FTIR)和扫描电镜(SEM)技术测试了热解炭的结构特性、表面特性以及物理化学性质.结果表明,这两种热解炭经过活化后可以获得许多优良的性质,固定碳含量增加,灰分含量减少.同时,活化后BET比表面积迅速增大,超过1100m2/g,而且热解炭的石墨化程度都有所加深.热解炭通过活化过程可以实现其高品质利用,有利于生物质热裂解技术的工业化发展.%The pyrolytic chars from fast pyrolysis of rosewood and rice husk have been activated with KOH solvent. The texture and structure, surface properties and physico-chemical properties of the pyrolytic chars have been characterized by N2 physisorption, X-ray diffraction (XRD), Fourier transform infrared spectroscopy ( FTIR) and Scanning electron microscope ( SEM). Compared with the original pyrolytic chars, the activated chars had higher fixed carbon content and lower ash content. The BET surface area increased beyond 1100m /g after activation. Moreover,the activated chars had higher graphitization degree. Through this activation process, high grade utilization of pyrolytic char will be achieved, as will benefit the industrialization of biomass fast pyrolysis technology.

  4. Measurements of Gasification Characteristics of Coal and Char in CO2-Rich Gas Flow by TG-DTA

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2013-01-01

    Full Text Available Pyrolysis, combustion, and gasification properties of pulverized coal and char in CO2-rich gas flow were investigated by using gravimetric-differential thermal analysis (TG-DTA with changing O2%, heating temperature gradient, and flow rate of CO2-rich gases provided. Together with TG-DTA, flue gas generated from the heated coal, such as CO, CO2, and hydrocarbons (HCs, was analyzed simultaneously on the heating process. The optimum O2% in CO2-rich gas for combustion and gasification of coal or char was discussed by analyzing flue gas with changing O2 from 0 to 5%. The experimental results indicate that O2% has an especially large effect on carbon oxidation at temperature less than 1100°C, and lower O2 concentration promotes gasification reaction by producing CO gas over 1100°C in temperature. The TG-DTA results with gas analyses have presented basic reference data that show the effects of O2 concentration and heating rate on coal physical and chemical behaviors for the expected technologies on coal gasification in CO2-rich gas and oxygen combustion and underground coal gasification.

  5. Odor and VOC Emissions from Pan Frying of Mackerel at Three Stages: Raw, Well-Done, and Charred

    Directory of Open Access Journals (Sweden)

    Jeong-Hyeon Ahn

    2014-11-01

    Full Text Available Many classes of odorants and volatile organic compounds that are deleterious to our wellbeing can be emitted from diverse cooking activities. Once emitted, they can persist in our living space for varying durations. In this study, various volatile organic compounds released prior to and during the pan frying of fish (mackerel were analyzed at three different cooking stages (stage 1 = raw (R, stage 2 = well-done (W, and stage 3 = overcooked/charred (O. Generally, most volatile organic compounds recorded their highest concentration levels at stage 3 (O, e.g., 465 (trimethylamine and 106 ppb (acetic acid. In contrast, at stage 2 (W, the lowest volatile organic compounds emissions were observed. The overall results of this study confirm that trimethylamine is identified as the strongest odorous compound, especially prior to cooking (stage 1 (R and during overcooking leading to charring (stage 3 (O. As there is a paucity of research effort to measure odor intensities from pan frying of mackerel, this study will provide valuable information regarding the management of indoor air quality.

  6. Modeling the Pyrolysis and Combustion Behaviors of Non-Charring and Intumescent-Protected Polymers Using “FiresCone”

    Directory of Open Access Journals (Sweden)

    Long Shi

    2015-10-01

    Full Text Available A mathematical model, named FiresCone, was developed to simulate the pyrolysis and combustion processes of different types of combustible materials, which also took into account both gas and solid phases. In the present study, some non-charring and intumescent-protected polymer samples were investigated regarding their combustion behaviors in response to pre-determined external heat fluxes. The modeling results were validated against the experimental outcomes obtained from a cone calorimeter. The predicted mass loss rates of the samples were found to fit reasonably well with the experimental data collected under various levels of external irradiation. Both the experimental and modeling results showed that the peak mass loss rate of the non-charring polymer material occurred near the end of burning, whereas for the intumescent-protected polymer it happed shortly after the start of the experiment. “FiresCone” is expected to act as a practical tool for the investigation of fire behavior of combustible materials. It is also expected to model fire scenarios under complicated conditions.

  7. Effect of sewage sledge and their bio-char on some soil qualities in Second year cropping

    Science.gov (United States)

    fathi dokht, hamed; Movahedi Naeini, Seyed Alireza; Dordipor, Esmaeil; mirzanejad, moujan

    2016-04-01

    Bio char (BC) application as a soil amendment has achieved much interest and has been found that considerably improves soil nutrient status and crop yields on poor soils. However, information on the effect of BC on illitic soils in temperate climates is still insufficient. The primary objective in this study was to assess the influence of sewage sledge and their bio-char on the soil physical properties, nutrient status and plant production in Second year cropping. The result may also provide a reference for the use of biochars as a solution in agricultural waste management when sludge with considerable load of pathogens are involved. Soybean was already grown one year and will be repeated one more year with same treatments. The investigated soil properties included soil water content and mechanical resistance, pH, electrical conductivity (EC), calcium- acetate-lactate (CAL)-extractable P (PCAL) and K (KCAL), C, N, and nitrogen-supplying potential (NSP). The results show soil water content, potassium uptake and plant yield were increased. Heating sludge removed all pathogens and soybean yield was increased by 7%.

  8. Potential of aeration flow rate and bio-char addition to reduce greenhouse gas and ammonia emissions during manure composting

    DEFF Research Database (Denmark)

    Chowdhury, Md Albarune; de Neergaard, Andreas; Jensen, Lars Stoumann

    2014-01-01

    Aeration is an important factor influencing CO2, CH4, N2O and NH3 emissions from the composting process. Both CH4 and N2O are potent greenhouse gases (GHG) of high importance. Here, we examined the effects of high and low aeration rates together with addition of barley straw with and without bio......-char on GHG and NH3 emissions from composting cattle slurry and hen manure in small-scale laboratory composters. Depending on treatment, cumulative C losses via CO2 and CH4 emissions accounted for 11.4-22.5% and 0.004-0.2% of initial total carbon, while N losses as N2O and NH3 emissions comprised 0.......05-0.1% and 0.8-26.5% of initial total nitrogen, respectively. Decreasing the flow rate reduced cumulative NH3 losses non-significantly (by 88%) but significantly increased CH4 losses (by 51%) from composting of cattle slurry with barley straw. Among the hen manure treatments evaluated, bio-char addition...

  9. Preparation and characterisation of raw chars and physically activated carbons derived from marine Posidonia oceanica (L.) fibres

    Energy Technology Data Exchange (ETDEWEB)

    Ncibi, M.C., E-mail: ncibi_mc@yahoo.com [Laboratoire de chimie, Institut Superieur Agronomique, Chott Meriem 4042, Sousse (Tunisia); Unite de Recherche ' Chimie Appliquee et Environnement' , EPAM Sousse 4000 (Tunisia); Laboratoire COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France); Jeanne-Rose, V. [Laboratoire COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France); Mahjoub, B. [Laboratoire de chimie, Institut Superieur Agronomique, Chott Meriem 4042, Sousse (Tunisia); Unite de Recherche ' Chimie Appliquee et Environnement' , EPAM Sousse 4000 (Tunisia); Jean-Marius, C. [Laboratoire COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France); Lambert, J.; Ehrhardt, J.J. [Laboratoire de Chimie Physique et Microbiologie pour l' Environnement, UMR 7564 CNRS, Universites de Nancy, 405, rue de Vandoeuvre, F 56600 Villers-les-Nancy cedex (France); Bercion, Y. [Groupe de Technologie des Surfaces et Interfaces (GTSI), EA 2432, Faculte des Sciences Exactes et Naturelles, Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France); Seffen, M. [Laboratoire de chimie, Institut Superieur Agronomique, Chott Meriem 4042, Sousse (Tunisia); Unite de Recherche ' Chimie Appliquee et Environnement' , EPAM Sousse 4000 (Tunisia); Gaspard, S. [Laboratoire COVACHIMM, EA 3592 Universite des Antilles et de la Guyane, BP 250, 97157 Pointe a Pitre Cedex, Guadeloupe (France)

    2009-06-15

    Industrial valorisation of low cost and renewable biomass as raw precursor of activated carbon for environmental applications is an interesting alternative to costly commercial activated carbons. In this study, the possible use of Mediterranean, Posidonia oceanica fibrous biomass, as a precursor for chars and physically activated carbons, is investigated. Firstly, the raw marine material was chemically and biochemically characterised throughout dry-basis elemental, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) analysis. Then, several P. oceanica chars were prepared and characterised under different pyrolysis times and temperatures. In addition, physically activated carbons (PACs) were produced via water steam flow under various activation periods. The results showed that the pyrolysis induces the creation of pores at different levels with respect to the involved temperature. Thereafter, the physical activation tends to enhance the development of the porous structure. In that issue, the performed Brunauer-Emmett-Teller (BET) and Barrett-Joiner-Halenda (BJH) analysis revealed that the prepared PACs have a mainly mesoporous inner morphology with a varying fraction of micropores.

  10. Reconstruction of Biomass Combustion History Using Soot, Char, and Polycyclic Aromatic Hydrocarbons at Linsley Pond, Conn, USA

    Science.gov (United States)

    Yan, B.; Han, Y.; Peteet, D. M.

    2013-12-01

    Biomass burning has become recognized as one of key elements of climate change. The occurrence of fires is a complex function of climate, moisture, vegetation and landscape type. Fires impact environments in multiple ways, e.g., increase in soil erosion, change of vegetation type, and increase in nutrient levels in soils and lakes that receive runoff from burned areas. Sediment cores that contain an archive of deposition of combustion products can help reconstruct the history of past fires. In this study, alkylated PAHs and black carbon (char and soot) were used to explore the paleofire history reflected in a sediment core collected from Linsley Pond, Connecticut (41°18'N, 72 °45'W). Biomass type and combustion levels of these fires and whether they occurred locally or regionally can be derived from these indicators. Such details, together with other paleoenvironmental indicators recorded in sediment cores (e.g., pollen, macrofossils, and LOI) helped unravel the environmental conditions before and after fires. Alkanes, PAHs, alkylated PAHs, and the ratio of soot to char indicate that in the Younger Dryas, fire occurred at a relatively low temperature (i.e. smoldering), followed by an abrupt increase of flaming combustion of softwood (white pine) at the Holocene boundary. Our paleofire data supports the previous interpretations of a shift towards a warm and dry climate in the southern New England region at this time.

  11. Clean, premium-quality chars: Demineralized and carbon enriched. Final technical report, 1 September, 1992--31 August, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.V.; Malhotra, V.M.; Wiltowski, T. [Southern Illinois Univ., Carbondale, IL (United States)

    1993-12-31

    The overall objective of this two-year project was to evaluate methods of preparing demineralized and carbon enriched chars from Illinois Basin coals. The two processing steps, physical cleaning and devolatilization under different environments, led to the following results. Cleaning coal incompletely removes mineral matter which decreases catalytic activity and increases micropore structure. Water forms hydrogen bonds to oxygen functional groups in coal, and during drying, coals undergo structural changes which affect mild gasification. When methane reacts wit coal, devolatilization and carbon deposition occur, the rates of which depend on temperature and amount of ash. Thermal decomposition of IBC-101 coal starts at 300 C, which is much lower than previously believed, but maximum yields of liquids occur at 500 C for IBC-101 coal and at 550 C for IBC-102 coal. Aliphatic-to-aromatic ratios increase with increasing pyrolysis temperatures to 300 C and then decrease; therefore, liquids formed during gasification of 550 C or higher contain mainly aromatic compounds. Btu values of chars are higher after methane treatment than after helium treatment.

  12. Toxaphene in the aquatic environment of Greenland.

    Science.gov (United States)

    Vorkamp, Katrin; Rigét, Frank F; Dietz, Rune

    2015-05-01

    The octa- and nonachlorinated bornanes (toxaphene) CHBs 26, 40, 41, 44, 50 and 62 were analysed in Arctic char (Salvelinus alpinus), shorthorn sculpin (Myoxocephalus scorpius), ringed seal (Pusa hispida) and black guillemot eggs (Cepphus grylle) from Greenland. Despite their high trophic level, ringed seals had the lowest concentrations of these species, with a Σ6Toxaphene median concentration of 13-20 ng/g lipid weight (lw), suggesting metabolisation. The congener composition also suggests transformation of nona- to octachlorinated congeners. Black guillemot eggs had the highest concentrations (Σ6Toxaphene median concentration of 971 ng/g lw). Although concentrations were higher in East than in West Greenland differences were smaller than for other persistent organic pollutants. In a circumpolar context, toxaphene had the highest concentrations in the Canadian Arctic. Time trend analyses showed significant decreases for black guillemot eggs and juvenile ringed seals, with annual rates of -5 to -7% for Σ6Toxaphene. The decreases were generally steepest for CHBs 40, 41 and 44.

  13. Modelling turnover of Cs-137 in two subarctic salmonid ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Nordlinder, S.; Bergstroem, U. (Studsvik AB, Ecosafe, Nykoeping (Sweden)); Hammar, J. (Institute of Freshwater Research, Drottningholm (Sweden) Uppsala Univ. (Sweden). Dept. of Zoology); Notter, M. (Swedish Environmental Protection Agency, Solna (Sweden))

    1993-01-01

    The turnover of cesium-137 was simulated in two categories of subarctic, alpine lake ecosystems - a natural lake with Gammarus lacustris as major fish prey and a lake reservoir with introduced Mysis relicta as a new fish-food organism. The resulting concentrations of Cs-137 in two salmonid species - Arctic char (Salvelinus alpinus) and brown trout (Salmo trutta) - were calculated using a multi-compartment model. Observed data were taken from a major case study evaluating the distribution, pathways and major transport mechanisms of Chernobyl cesium through northern lake ecosystems in 1986-90. The aim of this study was to design a specific conceptual model for calculation of the levels of Cs-137 in fish from simple lake ecosystems, which could be adopted for other more complex types of lakes. A multi-compartment model of the ecosystem was designed and the equations were solved with the BIOPATH-code. The uncertainty of the results due to the uncertainty of input values was examined using the PRISM-system. The model gave good correlations to measured data for Cs-137 in water, zooplankton, macro invertebrates and fish in both lakes. The predicted levels in sediments were, however, considerably lower than the observed values. The inflow of Cs-137 from the drainage area to the two lakes was identified as the main contributor to the uncertainty of the long-term prognoses. 33 refs, 6 figs, 3 tabs.

  14. Stunning fish with CO2 or electricity: contradictory results on behavioural and physiological stress responses.

    Science.gov (United States)

    Gräns, A; Niklasson, L; Sandblom, E; Sundell, K; Algers, B; Berg, C; Lundh, T; Axelsson, M; Sundh, H; Kiessling, A

    2016-02-01

    Studies that address fish welfare before slaughter have concluded that many of the traditional systems used to stun fish including CO2 narcosis are unacceptable as they cause avoidable stress before death. One system recommended as a better alternative is electrical stunning, however, the welfare aspects of this method are not yet fully understood. To assess welfare in aquaculture both behavioural and physiological measurements have been used, but few studies have examined the relationship between these variables. In an on-site study aversive behaviours and several physiological stress indicators, including plasma levels of cortisol and ions as well as blood physiological variables, were compared in Arctic char (Salvelinus alpinus) stunned with CO2 or electricity. Exposure to water saturated with CO2 triggered aversive struggling and escape responses for several minutes before immobilization, whereas in fish exposed to an electric current immobilization was close to instant. On average, it took 5 min for the fish to recover from electrical stunning, whereas fish stunned with CO2 did not recover. Despite this, the electrically stunned fish had more than double the plasma levels of cortisol compared with fish stunned with CO2. This result is surprising considering that the behavioural reactions were much more pronounced following CO2 exposure. These contradictory results are discussed with regard to animal welfare and stress physiological responses. The present results emphasise the importance of using an integrative and interdisciplinary approach and to include both behavioural and physiological stress indicators in order to make accurate welfare assessments of fish in aquaculture.

  15. Consistency in trophic magnification factors of cyclic methyl siloxanes in pelagic freshwater food webs leading to brown trout.

    Science.gov (United States)

    Borgå, Katrine; Fjeld, Eirik; Kierkegaard, Amelie; McLachlan, Michael S

    2013-12-17

    Cyclic volatile methyl siloxanes (cVMS) concentrations were analyzed in the pelagic food web of two Norwegian lakes (Mjøsa, Randsfjorden), and in brown trout (Salmo trutta) and Arctic char (Salvelinus alpinus) collected in a reference lake (Femunden), in 2012. Lakes receiving discharge from wastewater treatment plants (Mjøsa and Randsfjorden) had cVMS concentrations in trout that were up to 2 orders of magnitude higher than those in Femunden, where most samples were close to the limit of quantification (LOQ). Food web biomagnification of cVMS in Mjøsa and Randsfjorden was quantified by estimation of trophic magnification factors (TMFs). TMF for legacy persistent organic pollutants (POPs) were analyzed for comparison. Both decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) biomagnified with TMFs of 2.9 (2.1-4.0) and 2.3 (1.8-3.0), respectively. Octamethylcyclotetrasiloxane (D4) was below the LOQ in the majority of samples and had substantially lower biomagnification than for D5 and D6. The cVMS TMFs did not differ between the lakes, whereas the legacy POP TMFs were higher in Mjøsa than inRandsfjorden. Whitefish had lower cVMS bioaccumulation compared to legacy POPs, and affected the TMF significance for cVMS, but not for POPs. TMFs of D5 and legacy contaminants in Lake Mjøsa were consistent with those previously measured in Mjøsa.

  16. Integrated production/use of ultra low-ash coal, premium liquids and clean char. Interim final technical report, 1 September, 1992--31 August, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, C.W.; Carlson, S.L. [Illinois State Geological Survey, Champaign, IL (United States); Fatemi, M. [Amoco Research Center, Naperville, IL (United States); Snoeyink, V.L.; Feizoulof, C.A. [Univ. of Illinois, Urbana, IL (United States); Klavetter, E. [Sandia National Labs., Albuquerque, NM (United States)

    1993-12-31

    The ultimate objective of this project is to attain high-value, coal-derived products, especially varieties of char, from Illinois coal. The chars (carbons) made in this study, because of their special properties, could become the marketable materials having the highest value in the product set. Tests this quarter followed up on an unexpected correlation of surface properties of a variety of oxidized carbons with adsorption phenomena. Additional oxidized carbons were made at the ISGS and tests to establish the reproducibility of results were begun. Work will be continued through December on a no-cost extension.

  17. Effects of Pressure on the Properties of Coal Char Under Gasification Conditions at High Initial Heating Rates

    Science.gov (United States)

    Shurtz, Randy Clark

    The effects of elevated pressure and high heating rates on coal pyrolysis and gasification were investigated. A high-pressure flat-flame burner (HPFFB) was designed and built to conduct these studies. The HPFFB was designed to provide an environment with laminar, dispersed entrained flow, with particle heating rates of ˜105 K/s, pressures of up to 15 atm, and gas temperatures of up to 2000 K. Residence times were varied from 30 to 700 ms in this study. Pyrolysis experiments were conducted at particle heating rates of ˜10 5 K/s and maximum gas temperatures of ˜1700 K at pressures of 1 to 15 atm. A new coal swelling correlation was developed that predicts the effects of heating rate, pressure, and coal rank on the swelling ratio at heating rates above ˜104 K/s. A coal swelling rank index system based on 13C-NMR chemical structural parameters was devised. The empirical swelling model requires user inputs of the coal ultimate and proximate analyses and the use of a transient particle energy balance to predict the maximum particle heating rate. The swelling model was used to explain differences in previously reported bituminous coal swelling ratios that were measured in facilities with different heating rates. Char gasification studies by CO2 were conducted on a subbituminous coal and 4 bituminous coals in the HPFFB. Pressures of 5, 10, and 15 atmospheres were used with gas compositions of 20, 40, and 90 mole % CO2. Gas conditions with peak temperatures of 1700 K to 2000 K were used, which resulted in char particle temperatures of 1000 K to 1800 K. Three gasification models were developed to fit and analyze the gasification data. A simple 1 st--order model was used to show that the measured gasification rates were far below the film-diffusion limit. The other two models, designated CCK and CCKN, were based on three versions of the CBK models. CCKN used an nth--order kinetic mechanism and CCK used a semi-global Langmuir-Hinshelwood kinetic mechanism. The two CCK

  18. 煤焦与生物质焦CO2共气化特性及分布活化能研究%Investigation on the Co-gasification of Coal Char With Biomass Char and the Distributed Activation Energy

    Institute of Scientific and Technical Information of China (English)

    高正阳; 胡佳琪; 郭振; 王星久; 吴小芳

    2011-01-01

    对煤焦、秸秆焦、木屑焦3种焦样及其掺混焦样进行了CO2气氛的共气化热重试验,研究了各焦样在不同催化剂添加条件下的气化特性,并对各种样品在反应过程中的分布活化能进行了计算与分析.研究结果表明:煤焦、秸秆焦、木屑焦3种焦样中煤焦的反应性显然较差;对于煤焦和秸秆焦,Na盐的催化效果优于Ca盐;对于木屑焦,Ca盐的催化效果更显著.Na盐与Ca盐的添加均可使秸秆焦气化反应速率显著增加,但反应所需温度的下降却不显著.在木屑焦中添加Na盐与Ca盐后,气化反应所需温度的下降比秸秆焦显著.对于煤焦,添加催化剂首先使气化所需温度显著下降,反应速率并不显著增加;但进一步增加催化剂,则主要使反应速率提高,反应所需温度不再显著下降.在反应过程中,各样品的分布活化能均表现出先升后降的趋势.样品中灰分的存在有助于焦样在热天平内气化反应的充分进行.%Thermo gravimetric analyzer (TGA) experiments for gasification of sawdust char, wheat straw char and coal char and co-gasification of their mixtures in CO2 atmosphere were conducted. Characteristics of the gasification with and without catalysts were investigated. Kinetics of char gasification was studied employing distributed activation energy model (DAEM). Experimental data indicate that coal char is apparently less active among these three kinds of char. And catalytic effect of Na salts on the gasification of coal char or straw char is greater than Ca slats while Ca salts function as better catalysts to the gasification of sawdust char. Both Na salts and Ca salts have the ability to significantly accelerate the reaction rate of straw char gasification, but none of them would significantly reduce the onset temperatures of these reactions. When Na salts or Ca salts were added into sawdust char, drop of the onset temperature is larger than that can be observed in the

  19. Integrated production/use of ultra low-ash coal, premium liquids and clean char. Technical report, December 1--February 28, 1993

    Energy Technology Data Exchange (ETDEWEB)

    en; Kruse, C.W.; Carlson, S.L. [Illinois Dept. of Energy and Natural Resources, Springfield, IL (United States). Geological Survey; Fatemi, M. [Amoco Research Center, Naperville, IL (United States); Snoeyink, V.L.; Feizoulof, C.A. [Illinois Univ., Urbana, IL (United States); Klavetter, E. [Sandia National Labs., Albuquerque, NM (United States); Banerjee, D.D. [Illinois Clean Coal Inst., Carterville, IL (United States)

    1993-05-01

    The objective of this research is to invert the conventional scale of values normally assigned to products of coal utilization processes and make special coal chars (carbons) that, because of their special properties, can be among the most marketable materials in the product slate. Reconstruction of a continuous feed charring oven of the type used at the ISGS in 1979 was completed and its operation has been tested on an Illinois No. 6 coal. Pounds of per hour can be processed with this device and it accepts coal of all particle sizes. Effects on char properties related to the depth of the bed charred can be studied in this oven. Attempts are continuing to develop and prove procedures for comparing the catalyst activity of oxidized activated carbons. In the new studies, dehydrochlorination reactions were carried out in the gas phase and they were applied to alkyl chlorides less reactive than the tertiary chlorides used previously. Adsorption studies show the capacity of carbons made in this study, as measured by the Freundlich equation, have significantly less capacity than that of AR000, a commercially available activated carbon manufactured from bituminous coal.

  20. 基于XPS的纤维素热解焦表面结构分析%Surface Structure of Pyrolytic Char of Cellulose Based on XPS Analysis

    Institute of Scientific and Technical Information of China (English)

    王鹏; 张坚; 陈振国; 张彪; 龚勋; 徐明厚

    2015-01-01

    以XPS为主要分析手段,以管式炉和金属网为反应器,在300,℃不同热解时间下制备焦,利用XPS表征两种反应器制备的焦及水洗后的焦样的表面结构差异,进而分析挥发分与焦的二次反应对纤维素热解焦结构的影响。研究结果表明,纤维素在一次反应过程中生成了C=O双键。%In this paper,XPS is taken as the main means of analysis,and char is prepared in metal mesh reactor and horizon tube furnace reactor by heating cellulose at 300,℃. The surface structure of char in two reactors and of the char-washed samples is analyzed by XPS and the differences are made clear. Further,the impact of secondary reac-tions between volatile and char on the surface structure of cellulose is analyzed. The bond of C=O may be produced at the condition of minimized secondary reactions.

  1. Investigation of biomasses and chars obtained from pyrolysis of different biomasses with solid-state 13C and 23Na nuclear magnetic resonance spectroscopy

    NARCIS (Netherlands)

    Link, S.; Arvelakis, S.; Spliethoff, H.; Waard, de P.; Samoson, A.

    2008-01-01

    A number of biomass samples (reed, pine pellets, Douglas fir wood chips, wheat straw, peach stones, and olive residue), pretreated biomass samples (leached wheat straw, leached peach stones, and leached olive residue), as well as their chars obtained by pyrolysis using different heating rates (5, 10

  2. Study on demetalization of sewage sludge by sequential extraction before liquefaction for the production of cleaner bio-oil and bio-char.

    Science.gov (United States)

    Leng, Lijian; Yuan, Xingzhong; Shao, Jianguang; Huang, Huajun; Wang, Hou; Li, Hui; Chen, Xiaohong; Zeng, Guangming

    2016-01-01

    Demetalization of sewage sludge (SS) by sequential extraction before liquefaction was implemented to produce cleaner bio-char and bio-oil. Demetalization steps 1 and 2 did not cause much organic matter loss on SS, and thus the bio-oil and bio-char yields and the compositions of bio-oils were also not affected significantly. However, the demetalization procedures resulted in the production of cleaner bio-chars and bio-oils. The total concentrations and the acid soluble/exchangeable fraction (F1 fraction, the most toxic heavy metal fraction) of heavy metals (Cu, Cr, Pb, Zn, and Cd) in these products were significantly reduced and the environmental risks of these products were also relived considerably compared with those produced from raw SS, respectively. Additionally, these bio-oils had less heavy fractions. Demetalization processes with removal of F1 and F2 fractions of heavy metals would benefit the production of cleaner bio-char and bio-oil by liquefaction of heavy metal abundant biomass like SS.

  3. Promotion of hydrogen-rich gas and phenolic-rich bio-oil production from green macroalgae Cladophora glomerata via pyrolysis over its bio-char.

    Science.gov (United States)

    Norouzi, Omid; Jafarian, Sajedeh; Safari, Farid; Tavasoli, Ahmad; Nejati, Behnam

    2016-11-01

    Conversion of Cladophora glomerata (C. glomerata) as a Caspian Sea's green macroalgae into gaseous, liquid and solid products was carried out via pyrolysis at different temperatures to determine its potential for bio-oil and hydrogen-rich gas production for further industrial utilization. Non-catalytic tests were performed to determine the optimum condition for bio-oil production. The highest portion of bio-oil was retrieved at 500°C. The catalytic test was performed using the bio-char derived at 500°C as a catalyst. Effect of the addition of the algal bio-char on the composition of the bio-oil and also gaseous products was investigated. Pyrolysis derived bio-char was characterized by BET, FESEM and ICP method to show its surface area, porosity, and presence of inorganic metals on its surface, respectively. Phenols were increased from 8.5 to 20.76area% by the addition of bio-char. Moreover, the hydrogen concentration and hydrogen selectivity were also enhanced by the factors of 1.37, 1.59 respectively.

  4. Analysis of Hydrogen Generation through Thermochemical Gasification of Coconut Shell Using Thermodynamic Equilibrium Model Considering Char and Tar

    Science.gov (United States)

    Rupesh, Shanmughom; Muraleedharan, Chandrasekharan; Arun, Palatel

    2014-01-01

    This work investigates the potential of coconut shell for air-steam gasification using thermodynamic equilibrium model. A thermodynamic equilibrium model considering tar and realistic char conversion was developed using MATLAB software to predict the product gas composition. After comparing it with experimental results the prediction capability of the model is enhanced by multiplying equilibrium constants with suitable coefficients. The modified model is used to study the effect of key process parameters like temperature, steam to biomass ratio, and equivalence ratio on product gas yield, composition, and heating value of syngas along with gasification efficiency. For a steam to biomass ratio of unity, the maximum mole fraction of hydrogen in the product gas is found to be 36.14% with a lower heating value of 7.49 MJ/Nm3 at a gasification temperature of 1500 K and equivalence ratio of 0.15. PMID:27433487

  5. Corn stalks char from fast pyrolysis as precursor material for preparation of activated carbon in fluidized bed reactor.

    Science.gov (United States)

    Wang, Zhiqi; Wu, Jingli; He, Tao; Wu, Jinhu

    2014-09-01

    Corn stalks char from fast pyrolysis was activated by physical and chemical activation process in a fluidized bed reactor. The structure and morphology of the carbons were characterized by N2 adsorption and SEM. Effects of activation time and activation agents on the structure of activation carbon were investigated. The physically activated carbons with CO2 have BET specific surface area up to 880 m(2)/g, and exhibit microporous structure. The chemically activated carbons with H3PO4 have BET specific surface area up to 600 m(2)/g, and exhibit mesoporous structure. The surface morphology shows that physically activated carbons exhibit fibrous like structure in nature with long ridges, resembling parallel lines. Whereas chemically activated carbons have cross-interconnected smooth open pores without the fibrous like structure.

  6. Analysis of Hydrogen Generation through Thermochemical Gasification of Coconut Shell Using Thermodynamic Equilibrium Model Considering Char and Tar.

    Science.gov (United States)

    Rupesh, Shanmughom; Muraleedharan, Chandrasekharan; Arun, Palatel

    2014-01-01

    This work investigates the potential of coconut shell for air-steam gasification using thermodynamic equilibrium model. A thermodynamic equilibrium model considering tar and realistic char conversion was developed using MATLAB software to predict the product gas composition. After comparing it with experimental results the prediction capability of the model is enhanced by multiplying equilibrium constants with suitable coefficients. The modified model is used to study the effect of key process parameters like temperature, steam to biomass ratio, and equivalence ratio on product gas yield, composition, and heating value of syngas along with gasification efficiency. For a steam to biomass ratio of unity, the maximum mole fraction of hydrogen in the product gas is found to be 36.14% with a lower heating value of 7.49 MJ/Nm(3) at a gasification temperature of 1500 K and equivalence ratio of 0.15.

  7. Reprodução do papagaio charão, Amazona pretrei (Aves: Psittacidae em cativeiro.

    Directory of Open Access Journals (Sweden)

    Dionisio Link

    2009-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 O papagaio charão, Amazona pretrei (Temminck, 1830 pode ser reproduzido em cativeiro. O viveiro deve ser amplo para que o comportamento de acasalamento e reprodução seja o mais semelhante ao ambiente natural. Os casais deve ficar isolados de outros exemplares da mesma espécie e de outras aves. A alimentação deve ser colocada a uma certa altura do solo. O ninho deve ter dimensões que permitam à fêmea boas condições de oviposição e choco e, aos filhotes, proteção durante o período que ficam no ninho. A fase imatura é de aproximadamente dois anos.

  8. Investigations of Bull Trout (Salvelinus Confluentus), Steelhead Trout (Oncorhynchus Mykiss), and Spring Chinook Salmon (O. Tshawytscha) Interactions in Southeast Washington Streams : 1991 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Steven W.

    1992-07-01

    Bull trout (Salvelinus confluentus) are native to many tributaries of the Snake River in southeast Washington. The Washington Department of Wildlife (WDW) and the American Fisheries Society (AFS) have identified bull trout as a species of special concern which means that they may become threatened or endangered by relatively, minor disturbances to their habitat. Steelhead trout/rainbow trout (Oncorhynchus mykiss) and spring chinook salmon (O.tshawytscha) are also native to several tributaries of the Snake river in southeast Washington. These species of migratory fishes are depressed, partially due to the construction of several dams on the lower Snake river. In response to decreased run size, large hatchery program were initiated to produce juvenile steelhead and salmon to supplement repressed tributary stocks, a practice known as supplementation. There is a concern that supplementing streams with artificially high numbers of steelhead and salmon may have an impact on resident bull trout in these streams. Historically, these three species of fish existed together in large numbers, however, the amount of high-quality habitat necessary for reproduction and rearing has been severely reduced in recent years, as compared to historic amounts. The findings of the first year of a two year study aimed at identifying species interactions in southeast Washington streams are presented in this report. Data was collected to assess population dynamics; habitat utilization and preference, feeding habits, fish movement and migration, age, condition, growth, and the spawning requirements of bull trout in each of four streams. A comparison of the indices was then made between the study streams to determine if bull trout differ in the presence of the putative competitor species. Bull trout populations were highest in the Tucannon River (supplemented stream), followed by Mill Creek (unsupplemented stream). Young of the year bull trout utilized riffle and cascade habitat the most in all

  9. Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal. Part IV. Catalytic effects of NaCl and ion-exchangeable Na in coal on char reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Dimple Mody Quyn; Hongwei Wu; Jun-ichiro Hayashi; Chun-Zhu Li, [Monash University, Monash, Vic. (Australia). CRC for Clean Power from Lignite, Department of Chemical Engineering

    2003-03-01

    The purpose of this study is to investigate the catalytic effects of Na as NaCl or as sodium carboxylates ( COONa) in Victorian brown coal on the char reactivity. A Na-exchanged coal and a set of NaCl-loaded coal samples prepared from a Loy Yang brown coal were pyrolysed in a fluidised-bed/fixed-bed reactor and in a thermogravimetric analyser (TGA). The reactivities of the chars were measured in air at 400{sup o}C using the TGA. The experimental data indicate that the Na in coal as NaCl and as sodium carboxylates ( COONa) had very different catalytic effects on the char reactivity. It is the chemical form and dispersion of Na in char, not in coal, that govern the catalytic effects of Na. For the Na-form (Na-exchanged) coal, the char reactivity increased with increasing pyrolysis temperature from 500 to 700{sup o}C and then decreased with pyrolysis temperature from 700 to 900{sup o}C. The increase in reactivity with pyrolysis temperature (500 700{sup o}C) is mainly due to the changes in the relative distribution of Na in the char matrix and on the pore surface. For the NaCl-loaded coals, when Cl was released during pyrolysis or gasification, the Na originally present in coal as NaCl showed good catalytic effects for the char gasification. Otherwise, Cl would combine with Na in the char to form NaCl during gasification, preventing Na from becoming an active catalyst. Controlling the pyrolysis conditions to favour the release of Cl can be a promising way to transform NaCl in coal into an active catalyst for char gasification. 38 refs., 5 figs.

  10. Caracterização dos produtos líquidos e do carvão da pirólise de serragem de eucalipto Characterization of liquid products and char from the pyrolysis of eucalyptus sawdust

    Directory of Open Access Journals (Sweden)

    Ayrton F. Martins

    2007-08-01

    Full Text Available This study proposes the low temperature pyrolysis as an alternative conversion process for residual biomass and for obtaining gaseous, liquid and solid chemical feedstocks. Using a bench electrical pyrolysis oven, four product fractions from eucalyptus sawdust were obtained: a gaseous one, two liquid (aqueous and oily, and a solid residue (char. These products were characterized by different analytical methods. The liquid fractions showed themselves as potential sources for input chemicals. The residual char revealed appreciable adsorption capability. The process demonstrated good efficiency, generating at least two fractions of great industrial interest: bio oil and char.

  11. Co-pyrolysis behaviour and kinetic of two typical solid wastes in China and characterisation of activated carbon prepared from pyrolytic char.

    Science.gov (United States)

    Ma, Yuhui; Niu, Ruxuan; Wang, Xiaona; Wang, Qunhui; Wang, Xiaoqiang; Sun, Xiaohong

    2014-11-01

    This is the first study on the co-pyrolysis of spent substrate of Pleurotus ostreatus and coal tar pitch, and the activated carbon prepared from the pyrolytic char. Thermogravimetry (TG) analysis was carried out taking spent substrate, coal tar pitch and spent substrate-coal tar pitch mixture. The activation energies of pyrolysis reactions were obtained via the Flynn-Wall-Ozawa and Kissinger-Akahira-Sunose methods. The kinetic models were determined by the master-plots method. The activated carbons were characterised by N2-adsorption, Fourier transform infrared spectroscopy and X-ray diffraction. Experimental results demonstrated a synergistic effect happened during co-pyrolysis, which was characterised by a decreased maximum decomposition rate and an enhanced char yield. The average activation energies of the pyrolysis reactions of spent substrate, coal tar pitch and the mixture were 115.94, 72.92 and 94.38 kJ mol(-1) for the Flynn-Wall-Ozawa method, and 112.17, 65.62 and 89.91 kJ mol(-1) for the Kissinger-Akahira-Sunose method. The reaction model functions were f(α) = (1-α)(3.42), (1-α)(1.72) and (1-α)(3.07) for spent substrate, coal tar pitch and the mixture, respectively. The mixture char-derived activated carbon had a Brunauer-Emmett-Teller surface area up to 1337 m(2) g(-1) and a total pore volume of 0.680 cm(3) g(-1). Mixing spent substrate with coal tar pitch led to the creation of more micropores and a higher surface area compared with the single spent substrate and coal tar pitch char. Also, the mixture char-derived activated carbon had a higher proportion of aromatic stacking. This study provides a reference for the utilisation of spent substrate and coal tar pitch via co-pyrolysis, and their pyrolytic char as a promising precursor of activated carbon.

  12. 热解过程中生物质半焦比热容的测定%Determination of specific heat capacity of biomass char during pyrolysis

    Institute of Scientific and Technical Information of China (English)

    陈群; 庞任重; 陈熙; 杨锐明; 禚玉群; 陈昌和

    2014-01-01

    The specific heat capacities of chars during primary pyrolysis of biomass with different conversion and the heat capacities of virgin biomass were determined.The ratio method was employed to measure the specific heat capacities of two biomass samples and their pyrolyzed chars through thermogravimetry and differential scanning calorimetry ( TG-DSC).A mathematical model was developed to calculate values of specific heat of chars.The results show that the specific heat capacitei s of the two biomass samples and their derived chars increase linearly within 60~200℃.The values oft he specific heat capacity fo the chars are lower than those fo the virgin biomass samples.The specific heat of chars decreases as the extent of pyrolysis increases.The calculated specific heat capacities from the developed mathematical model are quite close to those me asured by TG-DSC analyses eb twe n 150~200℃.%采用热重-差示量热扫描法( TG-DSC)测量了生物质和一次热解焦炭及不同转化率下半焦的比热容,建立了计算半焦比热容的数学模型并与实验测量结果进行了对比。结果表明,生物质样品和热解焦炭的比热容在60~200℃随温度升高而线性增大。生物质焦炭的比热容低于生物质样品的比热容,从60℃时的1.2 J/(g· K)增大到200℃附近的1.8~2.0 J/(g· K)。生物质半焦比热容随热解转化率的提高而降低。由半焦比热容数学模型计算得到的结果在接近150~200℃时与实验测定的半焦比热容数值基本一致。

  13. 生物质新生半焦与冷态半焦CO2气化活性差异分析%Comparative Investigation of the CO2 Gasification Characteristics of Biomass In-situ Char and Ex-situ Char

    Institute of Scientific and Technical Information of China (English)

    易秋明; 刘华财; 阴秀丽; 吴创之

    2015-01-01

    以稻秆和松木为原料,采用恒温热重法对生物质新生半焦与冷态半焦的 CO2气化特性进行了对比研究。通过酸洗脱灰和对脱灰原料添加金属催化剂,分别从半焦结构和催化剂的角度探讨两种半焦气化反应性差异的成因,并采用混合模型进行了动力学分析。结果表明:新生半焦气化反应性明显大于冷态半焦。在冷却再升温过程中,半焦残留的有机官能团发生了进一步的断裂和重组,析出挥发分并生成更稳定的芳香结构;另一方面,半焦中金属催化剂晶型发生变化,金属元素与碳基质形成了更稳定的联接,使其催化活性减弱。新生半焦与冷态半焦气化反应活化能相差不大,但指前因子相差较大,这与两种半焦表面气化活性位点的数目有关。%The CO2 gasification characteristics of in-situ char and ex-situ char of biomass were comparatively investigated by using rice straw and pine as samples. Effects of char structure and metal catalyst on difference of the char gasification reactivity were explored by acid-washing and catalyst loading, respectively. Kinetic analysis was conducted with a hybrid model. The results show that, gasification reactivity of in-situ char is significantly higher than that of ex-situ char. During the process of cooling and reheating, the organic functional groups in char undergo further breakage and recombination, leading to volatilization and more stable aromatic structures. Besides, the morphology of metal catalyst is changed and more stable linkage may be formed between metal and char matrix, which deactivate the catalyst. Activation energy of the in-situ char and the ex-situ char are slightly different from each other, while the pre-exponential factors differ widely, which can be attributed to the numbers of active spot on char surface.

  14. SiteChar. Characterisation of European CO2 storage. Deliverable 8.4. Quantitative social site characterisations

    Energy Technology Data Exchange (ETDEWEB)

    Brunsting, S.; Mastop, E.A. [ECN Policy Studies, Energy research Centre of the Netherlands ECN, Amsterdam (Netherlands); Kaiser, M.; Zimmer, R. [Unabhaengiges Institut fuer Umweltfragen UfU, Berlin (Germany)

    2013-06-15

    This report describes the results of the last stage of the in-depth social site characterisation activities at two prospective CCS sites as part of the SiteChar project: a CCS onshore site and a CCS offshore site. The onshore site is the Zalecze and Zuchlow site application (Poland - WP5) and the offshore site is the North Sea Moray Firth site (UK - WP3). This deliverable describes the results from a repeated quantitative measurement of local awareness, knowledge, and perceptions of CCS at both sites using representative surveys. For comparison and discussion of all SiteChar WP8 results we refer to the final summary report D8.5. The 2nd survey showed some interesting results. First of all, awareness of CCS was still very low. While in the UK around half of the respondents had at least heard of local plans for CCS, in Poland this was only 21%. It seems that awareness in the UK was mostly induced by specific plans in the area that were abandoned in the course of the SiteChar project. Second, it seems that on the whole the local publics were rather positive about CCS. Most respondents expected a positive impact of CCS on the region. In the UK, arguments for that were mainly economic, while in Poland arguments were mainly related to environmental concerns. Although there are some worries about risks of leakage, especially at the onshore site in Poland, people think that authorities will properly regulate CCS and monitor the safety of CCS. Expectations were mostly that it would be good for the country and that it will help reach international targets for CO2 reduction and buy time to develop renewable energy. Respondents seemed uncertain about the costs of using CCS and whether the technique is ready for widespread use. Especially in Poland people seemed to agree that CCS is essential for tackling climate change. Most differences between the two sites may be attributed to the proximity of the site to the local community. The Polish site is onshore and therefore much

  15. CO2 GASIFICATION REACTIVITY OF BROWN COAL CHAR%一种褐煤热解煤焦的CO2气化反应特性

    Institute of Scientific and Technical Information of China (English)

    范冬梅; 张海霞; 朱治平; 吕清刚

    2012-01-01

    Based on the step utilization of brown coal pyrolysis, partial gasification, and residual carbon combustion, a brown coal from Shigouyi Coal Mine in Ningxia was chosen as research object to produce the rapid and slow coal chars at temperature of 700 ℃-950 ℃ in a hori- zontal tube furnace. The effect of pyrolysis conditions on carbon microcrystal structure and BET surface area of chars was investigated. The carbon dioxide gasification reactivity was analyzed by thermogravimetric-mass spectrometric technology, and different evolution indexes were used to characterize the reactivity of chars. It is found that the gasification rate of Shigouyi chars increases by more than 50% with the temperature increasing by 50 ℃. When the pyrolysis temperature rises, the carbon microcrystal structure of coal chars becomes more orderly and the BET surface area decreases. However, the gasification reactivity is mainly controlled by gasification temperature. The gasification reactivity of rapid pyrolyzed coal char is better than that of slow pyrolyzed coal char, and the difference between them become greater as gasification temperature rises. Average specific reaction rates of both rapid and slow pyrolyzed chars have a linear relationship with reaction index.%针对褐煤的热解-部分气化-残炭燃烧梯级利用工艺,以宁夏石沟驿褐煤为原料,采用水平管式炉在700℃~950℃温度范围内分别制备快速和慢速热解煤焦,考察了煤焦微晶结构和比表面积随制焦条件的变化.利用热重-质谱联用技术研究煤焦CO2气化反应特性,并采用不同评价指标对煤焦气化活性进行了表征.结果表明:气化温度每升高50℃,煤焦CO2气化反应速率增加50%以上;热解温度升高,虽然煤焦微晶结构的有序化程度加深,比表面积减小,但煤焦CO2气化反应活性主要受气化温度影响;快速热解煤焦的CO2气化反应活性高于慢速热解煤焦,二者的差异随着气化温度升

  16. The influence of gene-environment interactions on GHR and IGF-1 expression and their association with growth in brook charr, Salvelinus fontinalis (Mitchill

    Directory of Open Access Journals (Sweden)

    Blier Pierre

    2007-12-01

    Full Text Available Abstract Background Quantitative reaction norm theory proposes that genotype-by-environment interaction (GxE results from inter-individual differences of expression in adaptive suites of genes in distinct environments. However, environmental norms for actual gene suites are poorly documented. In this study, we investigated the effects of GxE interactions on levels of gene transcription and growth by documenting the impact of rearing environment (freshwater vs. saltwater, sex and genotypic (low vs. high estimated breeding value EBV effects on the transcription level of insulin-like growth factor (IGF-1 and growth hormone receptor (GHR in brook charr (Salvelinus fontinalis. Results Males grew faster than females (μ♀ = 1.20 ± 0.07 g·d-1, μ♂ = 1.46 ± 0.06 g·d-1 and high-EBV fish faster than low-EBV fish (μLOW = 0.97 ± 0.05 g·d-1, μHIGH = 1.58 ± 0.07 g·d-1; p FW = 1.52 ± 0.07 g·d-1, μSW = 1.15 ± 0.06 g·d-1, yet GHR mRNA transcription level was significantly higher in saltwater than in freshwater (μSW = 0.85 ± 0.05, μFW = 0.61 ± 0.05. The ratio of actual growth to units in assayed mRNA ('individual transcript efficiency', iTE; g·d-1·u-1 also differed among EBV groups (μLOW = 2.0 ± 0.24 g·d-1·u-1; μHIGH = 3.7 ± 0.24 g·d-1·u-1 and environments (μSW = 2.0 ± 0.25 g·d-1·u-1; μFW = 3.7 ± 0.25 g·d-1·u-1 for GHR. Males had a lower iTE for GHR than females (μ♂ = 2.4 ± 0.29 g·d-1·u-1; μ♀ = 3.1 ± 0.23 g·d-1·u-1. There was no difference in IGF-1 transcription level between environments (p > 0.7 or EBV groups (p > 0.15 but the level of IGF-1 was four times higher in males than females (μ♂ = 2.4 ± 0.11, μ♀ = 0.58 ± 0.09; p ♂ = 1.3 ± 0.59 g·d-1·u-1; μ♀ = 3.9 ± 0.47 g·d-1·u-1, salinities (μSW = 2.3 ± 0.52 g·d-1·u-1; μFW = 3.7 ± 0.53 g·d-1·u-1 and EBV-groups (μLOW = 2.4 ± 0.49 g·d-1·u-1; μHIGH = 3.8 ± 0.49 g·d-1·u-1. Interaction between EBV-group and environment was detected for

  17. Integrated production/use of ultra low-ash coal, premium liquids and clean char. Final technical report, September 1, 1991--August 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, C.W.; Carlson, S.L. [Illinois State Geological Survey, Champaign, IL (United States); Snoeyink, V.L.; Feizoulof, C.; Assanis; Syrimis, M. [Illinois Univ., Urbana (United States); Fatemi, S.M. [Amoco, Naperville, IL (United States)

    1992-12-31

    The objective of this research is to invert the conventional scale of values for products of coal utilization processes by making coal chars (carbons) that, because of their unique properties, are the most valuable materials in the product slate. A unique type of coal-derived carbon studied in this project is oxidized activated coal char having both adsorptive and catalyst properties. Major program elements were (a) preparation and characterization of materials (b) characterization of carbons and catalyst testing (c) completion of diesel engine testing of low-ash coal and (d) initiation of a two-year adsorption study. Materials prepared were (a) two low-ash coal samples one via ChemCoal processing of IBC-109 and the other by acid dissolution of IBC-109`s mineral matter, (b) coal char (MG char), (c) activated low-ash carbon (AC), (d) oxidized activated carbon (OAC). Amoco continued its support with state-of-the art analytical capabilities and development of catalyst testing procedures. Diesel engine tests were made with low ash coal dispersed in diesel fuel at solid loadings of 20% and 35%. The slurry was successfully burned in cylinder 2 of a two-cylinder diesel engine, after modifications of the engine`s fuel injection system. The higher speed proved to be more favorable but the slurry burned with a slightly improved thermal and combustion efficiency at both speeds with respect to diesel fuel alone. Adsorption studies included preparation of seven base-line carbon samples and their characterization, including their N{sub 2} BET surface areas and apparent densities. Paranitrophenol (PNP) adsorption isotherms were determined for the six controls. Oxidation of carbon with nitric acid decreases activated carbon`s PNP adsorption capacity while air oxidation increases adsorption capacity.

  18. Searching for long-term trends in prehistoric manuring practice. δ15N analyses of charred cereal grains from the 4th to the 1st millennium BC

    DEFF Research Database (Denmark)

    Kanstrup, Marie; Holst, M.K.; Jensen, Peter Mose;

    2014-01-01

    -base-acid) induced an average δ15N offset of 0.7‰ (pre-treated sample > non pre-treated sample). This has not previously been reported. Methodological advancements are needed to remedy this issue and provide consensus about appropriate pre-treatment of grain samples from archaeological sites. We conclude that N......-isotope analysis of charred cereal grains constitutes a new and direct source of information about prehistoric manuring practice....

  19. Reactivity to CO{sub 2} of chars prepared in O{sub 2}/N{sub 2} and O{sub 2}/CO{sub 2} mixtures for pulverized coal injection (PCI) in blast furnace in relation to char petrographic characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Pohlmann, Juliana G.; Osorio, Eduardo; Vilela, Antonio C.F. [Iron and Steelmaking Laboratory, UFRGS, Porto Alegre (Brazil); Borrego, Angeles G. [Instituto Nacional del Carbon, CSIC, Oviedo (Spain)

    2010-12-01

    Pulverized coal injection (PCI) is employed in blast furnace tuyeres in order to increase the injection rate without increasing the amount of unburned char inside the stack. When coal is injected with air in the region of tuyeres, the resolidified char will burn in an atmosphere with progressively lower oxygen content and higher CO{sub 2} concentration. In this study, an experimental approach comprising refiring has been followed to separate the combustion process into two distinct devolatilization and combustion steps. A drop tube furnace (DTF) operating at 1300 C in an atmosphere with low oxygen concentration was used to simulate devolatilization and then the char was refired into DTF at the same temperature under two different atmospheres O{sub 2}/N{sub 2} (typical combustion) and O{sub 2}/CO{sub 2} (oxy-combustion) with the same oxygen concentration. Coal injection was also performed under a higher oxygen concentration in both typical combustion and oxy-combustion atmospheres. The fuels tested comprised a petroleum coke and coals ranging in rank from high to low volatile bituminous, currently used for PCI injection. Specific surface areas, reactivity to CO{sub 2} and char petrography have been used to chars characterization. The morphology and appearance of the chars generated under oxy-fuel (O{sub 2}/CO{sub 2}) and conventional combustion (O{sub 2}/N{sub 2}) conditions with similar amount of oxygen were similar for each parent coal. Vitrinite-rich particles generated cenospheres with anisotropic optical texture increasing in size with increasing coal rank, whereas inertinite yielded a variety of morphologies and optical textures. The apparent reactivity to CO{sub 2} measured at high temperature (1000 C) tended to increase with burnout reflecting the operation under a regime controlled by internal diffusion in which surface area also increased. This may have a significant effect in the reactivity to CO{sub 2} of the chars inside the stack of the blast furnace

  20. Properties and Developments of Combustion and Gasification of Coal and Char in a CO2-Rich and Recycled Flue Gases Atmosphere by Rapid Heating

    Directory of Open Access Journals (Sweden)

    Zhigang Li

    2012-01-01

    Full Text Available Combustion and gasification properties of pulverized coal and char have been investigated experimentally under the conditions of high temperature gradient of order 200°C·s−1 by a CO2 gas laser beam and CO2-rich atmospheres with 5% and 10% O2. The laser heating makes a more ideal experimental condition compared with previous studies with a TG-DTA, because it is able to minimize effects of coal oxidation and combustion by rapid heating process like radiative heat transfer condition. The experimental results indicated that coal weight reduction ratio to gases followed the Arrhenius equation with increasing coal temperature; further which were increased around 5% with adding H2O in CO2-rich atmosphere. In addition, coal-water mixtures with different water/coal mass ratio were used in order to investigate roles of water vapor in the process of coal gasification and combustion. Furthermore, char-water mixtures with different water/char mass ratio were also measured in order to discuss the generation ratio of CO/CO2, and specified that the source of Hydrocarbons is volatile matter from coal. Moreover, it was confirmed that generations of CO and Hydrocarbons gases are mainly dependent on coal temperature and O2 concentration, and they are stimulated at temperature over 1000°C in the CO2-rich atmosphere.

  1. Mercury adsorption performance by modified mulberry twig chars%改性桑树枝焦对模拟烟气中汞的吸附性能

    Institute of Scientific and Technical Information of China (English)

    树童; 卢平; 何楠; 王秦超

    2013-01-01

    Several mulberry twig (MT) chars were prepared by conventional pyrolysis, steam activation, and impregnation with H2O2, ZnCl2 and NaCl. Adsorption performance of mercury in a simulated flue gas by MT chars were studied in a bench-scale fixed bed absorber, and the effects of steam activation, impregnation agent, adsorption temperature, and the composition of simulated flue gas, etc. on mercury adsorption performance were analyzed. The results indicated that steam activation could significantly increase surface areas of MT pyrolysis chars. Impregnation with H2O2 can further improve surface areas of steam activated MT chars and its pore structure. However, impregnation with ZnCl2 and NaCl led to decrease of surface areas, D-R micro-pore and total pore volume of MT chars in some extent. The mercury adsorption capacities of MT chars impregnated with 10% and 30% H2O2 were 2. 02 and 1. 77 times of that for steam activated MT char, respectively, and that of MT char impregnated with ZnCl2 was a little better than that impregnated with NaCl at the same impregnation concentration. The performance of mercury adsorption enhanced with increase of ZnCl2 concentration for modified MT char. The mercury adsorption for MT600-A-ZnCl2 (5 % ) was 29.55μg·g-1,3.37 times of that for steam activated MT char. At temperature of 60-120℃, the mercury adsorption efficiency and capacity of MT chars impregnated with H2O2 decreased with increase of adsorption temperature. However, the capacity of MT chars impregnated with ZnCl2 showed an increase trend at first and then decrease, and its optimum adsorption temperature was 90℃. SO2 and NO in the simulated flue gas showed adverse effect on mercury adsorption. Both mercury adsorption efficiency and capacity decreased slightly with increase of SO2 and NO concentration.%采用固定床热解、蒸汽活化和改性剂(H2O2、ZnCl2和NaCl)浸渍等方法制得不同的桑树枝焦.在固定床吸附实验台上,研究了蒸汽活化、改性剂

  2. Pyrolysis of waste animal fats in a fixed-bed reactor: production and characterization of bio-oil and bio-char.

    Science.gov (United States)

    Ben Hassen-Trabelsi, A; Kraiem, T; Naoui, S; Belayouni, H

    2014-01-01

    Several animal (lamb, poultry and swine) fatty wastes were pyrolyzed under nitrogen, in a laboratory scale fixed-bed reactor and the main products (liquid bio-oil, solid bio-char and syngas) were obtained. The purpose of this study is to produce and characterize bio-oil and bio-char obtained from pyrolysis of animal fatty wastes. The maximum production of bio-oil was achieved at a pyrolysis temperature of 500 °C and a heating rate of 5 °C/min. The chemical (GC-MS analyses) and spectroscopic analyses (FTIR analyses) of bio-oil showed that it is a complex mixture consisting of different classes of organic compounds, i.e., hydrocarbons (alkanes, alkenes, cyclic compounds...etc.), carboxylic acids, aldehydes, ketones, esters,...etc. According to fuel properties, produced bio-oils showed good properties, suitable for its use as an engine fuel or as a potential source for synthetic fuels and chemical feedstock. Obtained bio-chars had low carbon content and high ash content which make them unattractive for as renewable source energy.

  3. An integrated process for hydrogen-rich gas production from cotton stalks: The simultaneous gasification of pyrolysis gases and char in an entrained flow bed reactor.

    Science.gov (United States)

    Chen, Zhiyuan; Zhang, Suping; Chen, Zhenqi; Ding, Ding

    2015-12-01

    An integrated process (pyrolysis, gas-solid simultaneous gasification and catalytic steam reforming) was utilized to produce hydrogen-rich gas from cotton stalks. The simultaneous conversion of the pyrolysis products (char and pyrolysis gases) was emphatically investigated using an entrained flow bed reactor. More carbon of char is converted into hydrogen-rich gas in the simultaneous conversion process and the carbon conversion is increased from 78.84% to 92.06% compared with the two stages process (pyrolysis and catalytic steam reforming). The distribution of tar components is also changed in this process. The polycyclic aromatic compounds (PACs) of tar are converted into low-ring compounds or even chain compounds due to the catalysis of char. In addition, the carbon deposition yield over NiO/MgO catalyst in the steam reforming process is approximately 4 times higher without the simultaneous process. The potential H2 yield increases from 47.71 to 78.19g/kg cotton stalks due to the simultaneous conversion process.

  4. Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

    Institute of Scientific and Technical Information of China (English)

    Nurul A. Yunus; Mohd H. Ani; Hamzah M. Salleh; Rusila Z. A. Rashid; Tomohiro Akiyama; Hadi Purwanto; Nur E. F. Othman

    2014-01-01

    Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the mag-netization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was par-tially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic proper-ties.

  5. Effect of reduction roasting by using bio-char derived from empty fruit bunch on the magnetic properties of Malaysian iron ore

    Science.gov (United States)

    Yunus, Nurul A.; Ani, Mohd H.; Salleh, Hamzah M.; Rashid, Rusila Z. A.; Akiyama, Tomohiro; Purwanto, Hadi; Othman, Nur E. F.

    2014-04-01

    Beneficiation of Malaysian iron ore is becoming necessary as iron resources are depleting. However, the upgrading process is challenging because of the weak magnetic properties of Malaysian iron ore. In this study, bio-char derived from oil palm empty fruit bunch (EFB) was utilized as an energy source for reduction roasting. Mixtures of Malaysian iron ore and the bio-char were pressed into briquettes and subjected to reduction roasting processes at 873-1173 K. The extent of reduction was estimated on the basis of mass loss, and the magnetization of samples was measured using a vibrating sample magnetometer (VSM). When reduced at 873 K, the original goethite-rich ore was converted into hematite. An increase in temperature to 1073 K caused a significant conversion of hematite into magnetite and enhanced the magnetic susceptibility and saturation magnetization of samples. The magnetic properties diminished at 1173 K as the iron ore was partially reduced to wustite. This reduction roasting by using the bio-char can assist in upgrading the iron ore by improving its magnetic properties.

  6. Interaction of molten salts with a semi-anthracite char at 743 K. Influence on the gasification in air

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Serrano, V.; Alfaro-Dominguez, M.; Higes-Rolando, F.J. [Universidad de Extremadura, Badajoz (Spain). Dept. de Quimica Inorganica; Martin-Aranda, M.; Rojas-Cervantes, M.L.; Lopez-Peinado, A.J. [Universidad Nacional de Educacion a Distancia (UNED), Madrid (Spain). Dept. de Quimica Inorganica

    1997-12-31

    The treatments of a semi-anthracite char (AC) with molten salts followed by washing of the intermediate products with distilled water as a rule produce an increase in the surface area of micropores (S{sub mi}) and in the mean equivalent pore diameter (MEPD), which is greater for AC-MgO. The variation of MEPD is only slight for AC-CaO and AC-CoO. The reactivity of the carbon in air at 823 K enhances for a number of samples but especially for AC-CaO and AC-MgO. Washing with HCl generally results in a small increase in S{sub mi} and in a more uniform MEPD. The reactivity of the carbon decreases for most samples including AN and AC. This suggests that mineral components of the starting materials and chemical species present in distilled waterwashed samples (i.e. metal oxides in excess and reaction products of molten salts with the mineral fraction of AC) are catalytically active and that their removal from such samples occurs by washing with HCl. The presence of catalytic species seems to be greater for AC-MgO and AC-CaO than for the other samples. (orig.)

  7. Bio-oil and bio-char from low temperature pyrolysis of spent grains using activated alumina.

    Science.gov (United States)

    Sanna, Aimaro; Li, Sujing; Linforth, Rob; Smart, Katherine A; Andrésen, John M

    2011-11-01

    The pyrolysis of wheat and barley spent grains resulting from bio-ethanol and beer production respectively was investigated at temperatures between 460 and 540 °C using an activated alumina bed. The results showed that the bio-oil yield and quality depend principally on the applied temperature where pyrolysis at 460 °C leaves a bio-oil with lower nitrogen content in comparison with the original spent grains and low oxygen content. The viscosity profile of the spent grains indicated that activated alumina could promote liquefaction and prevent charring of the structure between 400 and 460 °C. The biochar contains about 10-12% of original carbon and 13-20% of starting nitrogen resulting very attractive as a soil amendment and for carbon sequestration. Overall, value can be added to the spent grains opening a new market in bio-fuel production without the needs of external energy. The bio-oil from spent grains could meet about 9% of the renewable obligation in the UK.

  8. Effect of Seed Sludge Quality using Oil Palm Empty Fruit Bunch (OPEFB Bio-Char for Composting

    Directory of Open Access Journals (Sweden)

    Wan Aizuddin Wan Razali

    2014-03-01

    Full Text Available In this study, a comparison between oil palm empty fruit bunch (OPEFB composting using palm oil mill effluent bio-char solution (POMEBS aerobic sludge and palm oil mill effluent (POME anaerobic sludge was reported. A set of experiments was designed by central composite design (CCD using response surface methodology (RSM to statistically evaluate the POMEBS aerobic sludge as microbial seeding. The bacteria count of POMEBS aerobic sludge (3.7×106 CFU/mL at the optimum point was higher than that of POME anaerobic sludge (2.5×105 CFU/mL. Denaturing gradient gel electrophoresis (DGGE and Fourier transform infrared spectroscopy (FTIR were also performed. A rotary drum composter was then used to compost OPEFB with POMEBS aerobic sludge and POME anaerobic sludge, separately. Thermogravimetric analysis (TGA showed that composting OPEFB with POMEBS aerobic sludge had a higher degradation rate compared to composting OPEFB with POME anaerobic sludge. In addition, the final N:P:K values for composting OPEFB with POMEBS aerobic and POME anaerobic sludge were 3.7:0.8:6.2 and 1.5:0.3:3.4, respectively. POMEBS aerobic sludge improved the composting process and compost quality.

  9. Preparation and properties of biomass char for ironmaking%炼铁用生物质焦的制备及其性能

    Institute of Scientific and Technical Information of China (English)

    胡正文; 张建良; 左海滨; 李净; 刘征建; 杨天钧

    2012-01-01

    采用两种不同的升温制度对生物质进行碳化,碳化温度选为300、400、500、600和700℃,保温时间分别为30、60和90min.利用扫描电镜及热重分析仪对所得生物质焦的成分、微观结构及燃烧性能等进行分析,并研究了制备条件对生物质焦的产率及与CO2反应性的影响.结果表明,生物质焦具有与煤不同的典型管状或片状结构,其N、S、灰分、碱金属含量及燃烧性能优于煤炭,适合用作炼铁过程的还原剂和发热剂,以替代部分煤粉和焦炭.综合考虑,炼铁用生物质焦的最佳制备条件是,采用恒温加热模式将生物质加热至500℃进行碳化,并保温30min.%Raw biomass was carbonized by two different heating patterns to produce biomass char at 400, 500, 600 and 700 ℃ for 30, 60 and 90 min. The composition, microstructure, and combustibility of the derived biomass char were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TG-DTG). The effects of preparing conditions on the biomass cbar's yield and reactivity for reacting with CO2 were studied. It is shown that the biomass char has typical duct structure or sheet structure, which is different from coal. The contents of N, S, ash and alkali metals in the biomass char are much lower, but its combustibility is better than coal samples, suitable for using as a reducing agent and a heating agent in ironmaking to partially replace coal and coke. The opti- mum preparing condition of biomass char for ironmaking is to carbonize raw biomass by a constant temperature heating pattern at 500 ℃ for 30 min.

  10. Effects of Pyrolysis Temperature on Characteristics of Biomass Char%热解温度对生物质半焦特征的影响

    Institute of Scientific and Technical Information of China (English)

    鲁许鳌; 冉旭; 郑小龙; 阎维平

    2012-01-01

    Mechanism-based pyrolysis experiments were carried out on rice husk and straw, during which physicochemical properties of the char were studied using TG, SEM, EDX and XDR, such as the pore structure, slagging characteristics, migration of chlorine and sulfur, and crystalline phase of the inorganic compound, etc. Results show that the pore structure of biomass char changes a lot at 500-800 ℃. When the pyrolysis temperature gets up to 1 000 ℃, the convex side of rice husk char will appear in melting state, while the straw char in melting and bounding condition. Most remaining of chlorine and sulfur will precipitate from the char at 800-1 000 ℃. The phase changes greatly and amorphous inorganic compound appears at a final pyrolysis temperature of 1 000 ℃ in the process of rice husk and straw pyrolysis.%对稻壳和稻秸进行了机理性热解试验,并采用TG、SEM、EDS和XDR方法研究和分析了半焦的孔隙结构、结渣特性、氯和硫元素迁移和无机化合物晶相等物化特性的变化规律.结果表明:在500~800℃,生物质热解半焦孔隙结构的变化较大.当热解温度为1000℃时,稻壳半焦的凸面呈现熔融现象,稻秸半焦呈现熔融黏结现象.在800~1000℃,半焦中剩余的氯和硫大部分会析出;在稻壳和稻秸热解过程中,当终温为1000℃时,物相发生较大变化并且出现非晶态的无机化合物.

  11. 不同温度热解残余生物质半焦对磷的吸附%Phosphate Adsorption of Residual Biomass Char by Pyrolysis

    Institute of Scientific and Technical Information of China (English)

    彭峰; 何丕文

    2011-01-01

    [ Objective ] The aim was to study adsorption of phosphorus in water by residual biomass char. [ Method ] The adsorption kinetics and isotherm of phosphate by biomass char obtained at different temperatures were studied. The pseudo first-order, pseudo second-order, intra-particle diffusion models and Langmuir, Freundlich isotherm models were employed to fit experimental data. [ Result ] The results showed that the adsorption of phosphate followed the pseudo second-order kinetics model and the equilibrium adsorption capacity and adsorption rate increased with the increasing of pyrolysis temperature. The adsorption isotherm was described by Freundlich model, which suggested that multiple processes controlled the serption of phosphate by biomass char. The adsorption activation energy of biomass chars at different temperatures were 10.86, 11.27 and 10.95 kJ/mol, which indicated that it belonged to physics adsorption. [ Conlusion ] The biomass char was approved that it had a good effect on adsorbing phosphate .%[目的]研究生物质热解制备生物油的残余半焦对水中磷的吸附性能.[方法]研究了不同温度(550、650和750 ℃)热解半焦吸附磷的动力学和等温线,分别采用准一级、准二级和颗粒内扩散3种模型及Langmuir、Freundlich等温吸附方程对实验数据进行拟合.[结果]结果表明准二级动力学模型能较好描述磷在半焦表面的吸附行为,平衡吸附量和吸附速率随着热解温度的升高而增加.此外,等温吸附过程能较好地用Freundlich吸附等温线方程描述,表明磷在半焦表面的吸附受多种机制影响.3种温度下热解所得半焦对磷的吸附活化能分别为10.86、11.27和10.95 kJ/mol,说明该吸附过程主要为物理吸附.[结论]生物质热解半焦对水中磷具有良好的吸附去除效果.

  12. 松木焦CO2气氛催化气化特性研究%STUDY ON CATALYTIC GASIFICATION CHARACTERISTICS OF PINE CHAR WITH CO2

    Institute of Scientific and Technical Information of China (English)

    蒲舸; 原志文; 郝功涛

    2013-01-01

    生物质焦CO2气化主要是通过气化剂CO2和焦中的碳发生反应,从而制取得到高纯度可燃气CO.采用热重分析法研究不同过渡金属催化剂(Ni,Ce,Fe和Cr)以及不同气化温度下松木焦在30% CO2气氛下的气化特性,采用n级反应模型并利用ABSW微分法,计算出高温段710℃~990℃松木焦催化气化动力学参数.结果表明,随着气化温度的升高,反应完成的时间缩短,气化温度达到850℃以上,才能有较高的反应速率,添加4种过渡金属对气化均有明显的促进作用.其催化效果由高到低依次为:Ni,Ce,Fe和Cr.采用n级反应模型可以很好地拟合高温段的实验数据.%Biomass char gasification with CO2 can produce high purity CO through the reaction of gasification agent CO2 with carbon in char. The effects of four transition metal catalysts (Ni, Ce, Fe and Cr) and four different gasification temperature on gasication of pine char were studied under 30% CO2 condition by using gravimetric analysis. And then the nth level reaction model was applied to calculate the kinetic parameters of catalytic gasification for pine char from 710℃ to 990 °C by ABSW differential method. The results indicated that with the increase of gasification temperature, the reaction time was obviously shortened. When the gasification temperature reached up to 850℃ , high reaction rate can be obtained. Moreover, the gasification reactivity of pine char with CO2 was significantly improved through the addition of four different transition metal catalysts. The order of catalytic activity from high to low was Ni, Ce, Fe and Cr. According to this study, it was found that the experimental data agreed better with the nth level reaction model at high temperature range.

  13. Effects of pyrolysis pressure on the properties and gasification reactivities of biomass chars%热解压力对生物质焦结构及气化反应性能的影响

    Institute of Scientific and Technical Information of China (English)

    丁亮; 张永奇; 黄戒介; 王志青; 房倚天

    2014-01-01

    Biomass chars were prepaer d under different pyrolysis pressurse in a pressurized fixed bed reactor. The evolution of chemical composition and physical structure of the biomass chars with the change of pyrolysis pressure were observed by BET, XRD, CHNS elemental analyzer and ICP-AES.The reactivit se of biomass c hars were evaluated by a thermgo ravimetric analyzer.The results show tah t the yields of biomsa s chars increase w ith ni creasing pyrlo ysis pressure, but reach a plateau above 1.0 MPa.With increasing pyrolysis pres ure C content in biomass chars icn reases, whiel H content and BET surface aread ecrease.The degree of graphitization of corn stalk char and sawdust char increases with increasing pyrolysis pressure, while thta of rice huks char shows almost no dependence on pyrolysis pressure.The average gasification rates of corn stalk char and sawdust char all decrease with increasing pyrolysis pressure, while pyrolysis pressure has little influence on the gasification rate of rice husk char.Compared the evolution of BETs urface area and carbon crystallti e structure of biomass chars with biomass char gasification rate, it shows that the difference of carbon crystallite structure of biomass chars, which was brought out by the change of pyrolysis pressure, mainly contributes to the difference of gasification rate of biomass chars prepared under different pyrolysis pressures.%利用加压固定床反应器、吸附仪、X射线衍射仪、元素分析仪、电感耦合等离子原子发射光谱仪等考察了热解压力对生物质半焦(以下简称半焦)产率、物化结构、元素组成的影响规律。同时,利用热天平对不同热解压力下所制半焦的气化行为进行了考察。结果表明,随热解压力升高,半焦产率增大,当压力升至1.0 MPa后,半焦产率基本不变;半焦中C元素含量随热解压力的升高而增加,而H元素含量和BET比表面积则减小;此外,随热解压力升高,

  14. Effect of char from municipal solid waste on pyrolysis oil%城市生活垃圾热解焦对热解焦油的影响

    Institute of Scientific and Technical Information of China (English)

    任善普; 宋强; 张蒙蒙; 舒新前

    2016-01-01

    The effect of char from Municipal Soild Waste (MSW) on pyrolysis oil was explored by means of a fixed bed reactor and gas charomatography-mass spectrometer (GC-MS).The products distribution and compounds of pyrolysis oil were investigated and analyzed.The result shown that when the temperature increased to 600 ℃,the yield of pyrolysis oil was 38.38%.When the char added up to 30%,the yield of pyrolysis oil reduced to 31.79%,the oxygen-carbon ratio of pyrolysis oil fallen from 0.20 to 0.10 and calorific value increased from 30.24 MJ/kg to 35.81 MJ/kg.The catalytic effect of char on pyrolysis oil was reduced when the ratios of char above 30%.When the char added up to 30%,the contact of the alcohols and carboxylic acids of pyrolysis oil were decreased by 19.18% and 13.73% respectively and the content of the esters and fatty hydrocarbons were increased by 27.69% and 5.63% respectively.The quality of pyrolysis oil improved by adding 30% char and the pyrolysis oil achieve heavy oil lightening.%为研究城市生活垃圾热解焦对城市生活垃圾热解焦油的影响,采用固定床对添加不同比例的城市生活垃圾热解焦的城市生活垃圾进行热解实验.实验结果表明:未添加热解焦时,城市生活垃圾热解焦油产率为38.38%;当热解焦添加比例为30%时,焦油产率为31.79%,焦油中的O/C由0.20下降到0.10,焦油热值由30.24 MJ/kg升高到35.81 MJ/kg;当热解焦添加量超过30%时,热解焦对热解焦油品质的改善作用减弱.利用GC-MS对热解焦油分析发现,热解焦添加比例为30%时,热解焦油中醇类和羧酸类分别下降了19.18%和13.73%,酯类和脂肪烃类分别增加了27.69%和5.63%.热解焦明显改善了热解焦油的品质,实现了一定程度的轻质化.

  15. Adding the combination of CNTs and MoS{sub 2} into halogen-free flame retarding TPEE with enhanced the anti-dripping behavior and char forming properties

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, Yuhua; Li, Maolin; Zhang, Luchong; Zhang, Xuewei; Zhu, Songwei; Wu, Wei, E-mail: wuwei@ecust.edu.cn

    2015-08-10

    Highlights: • Introduction the combination of the CNTs and MoS{sub 2} into P–N flame retarding TPEE. • Binary synergists for P–N flame retardants in TPEE. • Increase of char yield and form the stable carbonaceous char. - Abstract: In this paper, the nanocomposites thermoplastic polyester-ether elastomer (TPEE) with phosphorus–nitrogen (P–N) flame retardants, carbon nanotubes (CNTs) and molybdenum disulfide (MoS{sub 2}) was prepared by melt blending. TPEE containing P–N flame retardant, CNTs and MoS{sub 2} achieved UL94 V-0 rating due to the better barrier effect of the special structure. The structure was supported by the result of rheological properties. The thermal stability was studied by thermal gravimetric analysis (TGA) and char residue characterization was investigated by SEM–EDX measurements. The results demonstrated that the combination of CNTs and MoS{sub 2} results in the increase of char yield and the formation of the thermally stable char which can effectively prevent in the dripping behavior during the burning process.

  16. Experimental Study on Adsorption Characteristics of SO2 and NO Using Biomass-pyrolysis Chars%生物质热解焦吸附模拟烟气中SO2和NO的实验研究

    Institute of Scientific and Technical Information of China (English)

    卢平; 陆飞; 树童; 王秦超

    2012-01-01

    以麦秆、稻秆、棉花秆、玉米秆和稻壳等5种生物质原料为对象,在热解温度Tp=673~1 073 K范围内,采用快速热解和慢速热解方式制备了生物质焦,利用固定床吸附反应装置研究了焦粒粒径、热解温度、热解速率、烟气组成、吸附反应温度和生物质种类等因素对生物质焦吸附模拟烟气中SO2、NO的影响.结果表明:生物质焦对SO2的吸附效率和吸附量随着生物质焦粒径的减小而增加,但其增加趋势逐步减小.随着热解温度升高,生物质焦对SO2的吸附效率和吸附量均呈现先上升后下降的趋势.快速热解生物质焦对SO2和NO的单独吸附效率和吸附量均高于慢速热解焦.生物质焦对SO2和NO的吸附效率和吸附量均随着吸附反应温度的升高而下降.生物质焦对SO2吸附能力显著优于吸附NO的能力,模拟烟气中SO2组分对NO吸附具有显著促进作用.SO2和NO同时吸附时,WS-RP873型生物质焦对SO2的吸附量较单独吸附时减少了22.3%,但其对NO吸附量却提高了112%.在Tp=873 K快速热解条件下,各种生物质焦对SO2吸附量顺序为麦秆焦>玉米秆焦>稻秆焦>稻壳焦>棉花秆焦,对NO吸附量顺序为麦秆焦>稻秆焦>玉米秆焦>稻壳焦>棉花秆焦.%Biomass-pyrolysis chars were prepared under rapid pyrolysis and slow pyrolysis at pyrolysis temperature (Tp) of 673-1073 K from five kinds of biomass named wheat straw, rice straw, cotton stalk, maize stalk and rice husk. The effects of biomass char particle size, pyrolysis temperature, pyrolysis rate, composition of the simulated flue gas, adsorption reaction temperature, and biomass type on adsorption characteristics of SO2 and NO by using biomass-pyrolysis chars were carried out experimentally in a fixed-bed reactor. The results indicate that adsorption efficiency and adsorption capacity of SO2 over biomass-pyrolysis chars increase with decreasing the particle size of biomass chars

  17. 可扩展的字符命令实现机制研究%Implemention of Scalable Char Command Programming

    Institute of Scientific and Technical Information of China (English)

    李加洋; 吴文江; 韩建起

    2011-01-01

    General CNC system only provides G-code programming which lacks of flexibility and single scalability way. In order to enrich its programming mechanism and Improve CNC s scalability, this paper puts to use the custom sequence of syntax element analysis and propose a char command programming mechanism for Lantian CNC. The char command programming mechanism is very easy to extend. The advantage of the mechanism is that it allows the interpreter to add a char command without modificating the source code for lexical and syntax analysis. Users just need to make a little change on configuration file and all change can be realized Automatically. The paper also designs and implements the configuration files, configuration files parser, command parser and detailed introduces the three modules' achievement.%一般数控系统仅提供了G代码编程,缺少灵活性,扩展方式单一.为了丰富数控系统的编程机制,提高系统的可扩展性,采用自定义的语法元素分析序列方式,提出了一种易于扩展的用于蓝天数控系统的字符命令编程机制,该机制使得添加字符命令的解释工作可以在无需修改词法和语法分析源代码的情况下,通过配置文件实现.设计实现了配置文件,配置文件解析器以及命令解析器三个模块,并对这三个模块功能是实现做了详细的介绍.

  18. 生物质炭催化裂解焦油的性能研究%Study on biomass char on catalytic pyrolysis performance of tar

    Institute of Scientific and Technical Information of China (English)

    尤占平; 由世俊; 李宪莉; 焦永刚; 韩鹏

    2011-01-01

    In a tubular reactor,the catalytic performance of biomass char on tar cracking were studied. Dolomite and quartz sand were also tested for the comparison. Through analysis and comparisons on conversion rate of tar, pyrolysis products, pyrolysis gas composition and kinetic parameters, it could be known that biomass char, as the catalyst of tar, could realize the highest conversion rate of tar, the largest proportion of gas in pyrolysis products, the more proportion of combustible gas in pyrolysis gases and the lowest kinetic parameters among three catalytic materials used in the study. The catalytic performance of biomass char is significantly superior than that of quartz sand and slightly better than that of dolomite, so it is an efficient catalyst for tar cracking.%采用管式反应器研究了生物质炭作为焦油裂解催化剂的性能,选用白云石和石英砂作对比试验.通过对焦油转换率、裂解产物、裂解气气体组分和动力学参数的分析对比可知:在所选用的3种材料中,生物质炭作为催化剂的焦油转化率最高,裂解产物中气体所占比重最大,且可燃气体的组分较高,反应动力学参数最小.生物质炭的催化性能显著高于石英砂,稍好于白云石,是一种高效的焦油裂解催化剂.

  19. Modification of Coal Char-loaded TiO2 by Sulfonation and Alkylsilylation to Enhance Catalytic Activity in Styrene Oxidation with Hydrogen Peroxide as Oxidant

    Directory of Open Access Journals (Sweden)

    Mukhamad Nurhadi

    2017-04-01

    Full Text Available The modified coal char from low-rank coal by sulfonation, titanium impregnation and followed by alkyl silylation possesses high catalytic activity in styrene oxidation. The surface of coal char was undergone several steps as such: modification using concentrated sulfuric acid in the sulfonation process, impregnation of 500 mmol titanium(IV isopropoxide and followed by alkyl silylation of n-octadecyltriclorosilane (OTS. The catalysts were characterized by X-ray diffraction (XRD, IR spectroscopy, nitrogen adsorption, and hydrophobicity. The catalytic activity of the catalysts has been examined in the liquid phase styrene oxidation by using aqueous hydrogen peroxide as oxidant. The catalytic study showed the alkyl silylation could enhance the catalytic activity of Ti-SO3H/CC-600(2.0. High catalytic activity and reusability of the o-Ti-SO3H/CC-600(2.0 were related to the modification of local environment of titanium active sites and the enhancement the hydrophobicity of catalyst particle by alkyl silylation. Copyright © 2017 BCREC GROUP. All rights reserved Received: 24th May 2016; Revised: 11st October 2016; Accepted: 18th October 2016 How to Cite: Nurhadi, M. (2017. Modification of Coal Char-loaded TiO2 by Sulfonation and Alkylsilylation to Enhance Catalytic Activity in Styrene Oxidation with Hydrogen Peroxide as Oxidant. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (1: 55-61 (doi:10.9767/bcrec.12.1.501.55-61 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.12.1.501.55-61

  20. Reactivity of lignite chars with CO sub 2. Influence of mineral matter. Reactividad de semicoques de lignitos con CO sub 2; Influencia de la materia mineral

    Energy Technology Data Exchange (ETDEWEB)

    Adanez, J.; Diego, L.F. de (Instituto de Carboquimica, Zaragoza (Spain))

    1990-01-01

    The gasification reaction C + CO{sub 2} was studied using chars obtained from three lignites from the Teruel basin. Working conditions for the reactivity determination were: 900 to 1000{degree}C, atmospheric pressure, in a fluidized bed differential reactor. The kinetic model which best describes the progress of the reaction was found, corresponds to homogeneous model. Also the catalytic effect of mineral matter over gasification reaction was studied. It was found that the experimental results best fit to the homogeneous model without deactivation (k{sub d} 0) and moreover increasing the apparent kinetic reaction constant. 18 refs., 7 figs., 4 tabs.

  1. Tonalites and plagiogranites of the Char suture-shear zone in East Kazakhstan:Implications for the Kazakhstan-Siberia collision

    Institute of Scientific and Technical Information of China (English)

    M.L. Kuibida; I.Yu. Safonova; P.V. Yermolov; A.G. Vladimirov; N.N. Kruk; S. Yamamoto

    2016-01-01

    The paper presents first UePb zircon ages and geochemical data from Carboniferous granitoids (tonalites and plagiogranites) of the Char sutureeshear zone in East Kazakhstan, which is located in the north-western Central Asian Orogenic Belt (CAOB). The study included analysis of geological setting, major and trace elements, and rock petrogenesis. The Char tonalites and plagiogranites occur as NW-striking linear chains inside Visean serpentinite mélange. Petrographycally, the tonalites show signs of syntec-tonic deformation, and the plagiogranites are less deformed suggesting their later intrusion. The tonalites yielded a LA-ICP-MS zircon age of ca. 323 Ma, i.e. exactly at the boundary between the early and late Carboniferous. Compositionally, the tonalites and plagiogranites are characterized, respectively, by high SiO2 (67e70 and 73e74 wt.%) and Al2O3 (17e19 and 14e15 wt.%), Sr/Y>40 and low Yb ¼ 0.2e0.5 ppm. Their multi-element patterns show clear Nb-Ta negative anomalies. The low Nb/Ta ratios (7e15) and Zr (114e191 ppm) suggest a MORB-type protolith (amphibolite) with subchondritic Nb/Ta (8e17) and low Zr (1e72 ppm). The low contents of K and Rb suggest weak assimilation of the melts by island arc felsic crust. The subchondritic Nb/Ta ratios exclude their derivation by the melting of subducted/dehydrated MORB. We argue that the Char high-Al tonalites and plagiogranites formed by the melting of hydrated MORB at the base of the mafic lower crust at pressures of 10e15 kbar. The occurrences of the Char tonalites and plagiogranites inside the Visean serpentinite mélange overlapped by Serpukhovian con-glomerates, their alignment parallel to deformation zones, and their geochemical features suggest their origin by the melting of mafic lower crust in relation to the collision of the Siberian and Kazakhstan continents.

  2. PIV measurement of char powders motion in laminar entrained flow reactor%层流炉反应管内炭粉颗粒运动的PIV试验

    Institute of Scientific and Technical Information of China (English)

    王娜娜; 易维明; 刘珠伟; 柏雪源

    2011-01-01

    In order to study the movements of char powders in laminar entrained flow reactor, a transparent experimental apparatus was designed for Particle Image Velocimetry(PIV) measurement of flow field.The velocities of char powders whose mesh size was between 100 to 120 were investigated by PIV at the different flow rates of 1.0-2.5 m3/h.The results indicated that the axial velocity of char powers in the pipe center was very small near the outlet, subsequently rapidly reached the maximum and then decreased.The axial velocity at the center of pipe reached a maximum in the region within 1.8-123.8 mm.The axial velocity distribution was a parabola-like curve along the radius.The relationship between Re and the dimensionless residential time of char powders was obtained finally.%为了研究炭粉颗粒在层流炉反应管内的运动规律,按照1:1比例设计制造了一套透明玻璃试验装置用于PIV流场测量.分别在4种不同的主气流量下,对粒径为100~120目的炭粉颗粒在反应管内的速度场进行了PIV无接触测量.结果表明,在反应管中心处,开始时,炭粉颗粒的轴向速度在下料口附近很小,然后迅速增加到最大值,而后以此速度运动一段距离后,速度开始减小.在约1.8~123.8 mm段,炭粉颗粒的轴向速度在管道中心处为最大.轴向速度沿径向成类似抛物线状分布;通过对测量数据的分析计算,获得了管内气流雷诺数与炭粉颗粒停留时间(无量纲处理后)的关联式.

  3. Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production.

    Directory of Open Access Journals (Sweden)

    Gerard Cornelissen

    Full Text Available Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns, also avoiding use of external fuel for start-up.A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57, average surface areas (11 to 215 m2 g-1, low EPA16-PAHs (2.3 to 6.6 mg kg-1 and high CECs (43 to 217 cmolc/kg(average for all feedstocks, mainly woody shrubs were obtained, in compliance with the European Biochar Certificate (EBC.Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks; CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10 = 11 ± 15, total products of incomplete combustion (PIC = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (p<0.05 lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2.With benefits such as high quality biochar, low emission, no need for start-up fuel, fast pyrolysis time and, importantly, easy and cheap

  4. Linking charring temperature and wood source to the structure and degradation rates of pyrogenic organic matter in soil

    Science.gov (United States)

    Hatton, P.; Dastmalchi, K.; Chatterjee, S.; Auclerc, A.; Le Moine, J.; Filley, T. R.; Nadelhoffer, K. J.; Stark, R.; Bird, J. A.

    2013-12-01

    Fire is a major controller of forest C cycling by releasing CO2 to the atmosphere and by contributing pyrogenic organic matter (PyOM or biochar) to soils. Recent studies have shown that much of fire-derived PyOM may turn over in soils at century time scales. Two likely controllers of the chemical structure of PyOM and its resulting decay rate are pyrolysis temperature and the source biomass. However, we know little of how these two factors determine the chemical structure and bioreactivity of the resulting PyOM. To gain further insight into controls on the structure and fate of PyOM, we examined two species of dual-labeled (13C/15N), wood-based PyOM (Pinus banksiana and Acer rubrum) made with 5 pyrolysis temperatures (0, 200, 300, 450, 600 °C) using solid state nuclear magnetic resonance, isotopic and elemental composition (C, H, O, and N), and differential scanning calorimetry. In addition, we are investigating the fate of a subset of these PyOM materials applied to forest soils in a long-term field study located at the University of Michigan Biological Station in Pellston, MI, USA. We will present data of the loss of PyOM C as CO2 and DOC during the first year in situ. We found complementary lines of evidence for a facile removal of cellulose and hemicellulose and a progressive alteration of nitrogenous moieties across the charring gradient for wood-derived PyOM of both tree species as temperature was increased from 0 to 600 °C. Our NMR results show a significant species by pyrolysis temperature interaction on PyOM chemical structure with considerably less condensation for Acer- than Pinus-derived PyOM at 300 °C. In the first year after addition to soil, Acer-derived PyOM pyrolyzed at 450 °C mineralized faster than Pinus-derived PyOM pyrolyzed at 450 °C. Increasing pyrolysis temperatures for Pinus-derived PyOM also resulted in slower CO2 mineralization rates during the first year of field decay. These results relate pyrolysis temperature to the resulting Py

  5. Influence of silica on physicochemical characteristic of modified bio-chars%SiO2对改性生物质焦理化特性的影响

    Institute of Scientific and Technical Information of China (English)

    冯烨; 米铁; 张雄; 杨海平; 王贤华; 张世红; 陈汉平

    2014-01-01

    To study the effect of SiO2 on the physicochemical characteristic of modified biochar, bio-chars were obtained at 600℃in a vertical furnace from a pyrolysis of rice straw, cotton stalk, and rice husk. Bio-chars were activated at different temperatures (400, 600, 800, and 1 000℃) in a gaseous NH3 and/or CO2 atmosphere. The variation of chemical properties, the CO2 adsorption capacities, and the physicochemical properties linked with an ash analysis of different raw chars and modified chars were investigated. An X-ray fluorescence (EARGE Ⅲ, EDAX Inc.) and an ion chromatograph (ICS-90, Dionex) were used according to the national standard of GB/T1574 to analyze the ash composition of pyrolytic biochars. The content of SiO2 in rice husk char (87.47%) was the highest among the studied samples, followed by rice straw and cotton stalk chars, which were 51.99%and 18.21%, respectively. However, according to the proximate analysis of biomass raw materials, the proportion of ash in rice straw and rice husk was about 2-3 times of that of cotton stalk, therefore, the amount of SiO2 retained in rice husk and rice straw was nearly 15 times and 4-5 times of that in cotton stalk, respectively. The production and modification of biomass chars were carried out in a self-designed vertical furnace reaction system which included two parts: A gas generating zone and a modification reaction zone. The modification reaction zone mainly consisted of a stainless steel reactor (inner diameter 38 mm, outer diameter 40mm, and height 600 mm) and a temperature programmed furnace.A Fourier transform infrared spectrum analyzer (VERTEX70, Bruker) was used to analyze the variation of chemical properties and surface functional groups of biochars before and after NH3 modification at different temperatures. And the Fourier transform infrared spectra of the corresponding biomass raw materials linked with a proximate and ultimate analysis were also presented to compare with that of chars and modified

  6. Dynamic Energy Budgets and Bioaccumulation: A Model for Marine Mammals and Marine Mammal Populations

    Science.gov (United States)

    2006-06-01

    Birnbaum, and M. DeVito. 2005. Comparison of the use of a physiologically based pharmacokinetic model and a classical pharmacokinetic model for dioxin ...status on biomarker responses to PCB in the arctic charr (Salvelinus alpinus). Aquatic Toxicology 44:233-244, Kann, L. M., and K. Wishner. 1995...description of the tissue distribution and enzyme-inducing properties of 2,3,7,8-tetrachlorodibenzo-p- dioxin in the rat. Toxicology and Applied

  7. Hydrogen-rich gas production by steam gasification of char from biomass fast pyrolysis in a fixed-bed reactor: influence of temperature and steam on hydrogen yield and syngas composition.

    Science.gov (United States)

    Yan, Feng; Luo, Si-yi; Hu, Zhi-quan; Xiao, Bo; Cheng, Gong

    2010-07-01

    Steam gasification experiments of biomass char were carried out in a fixed-bed reactor. The experiments were completed at bed temperature of 600-850 degrees C, a steam flow rate of 0-0.357 g/min/g of biomass char, and a reaction time of 15min. The aim of this study is to determine the effects of bed temperature and steam flow rate on syngas yield and its compositions. The results showed that both high gasification temperature and introduction of proper steam led to higher yield of dry gas and higher carbon conversion efficiency. However, excessive steam reduced gas yield and carbon conversion efficiency. The maximum dry gas yield was obtained at the gasification temperature of 850 degrees C and steam flow rate of 0.165 g/min/g biomass char.

  8. Integrated production/use of ultra low-ash coal, premium liquids and clean char. Technical report, March 1, 1992--May 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Kruse, C.W.; Carlson, S.L. [Illinois State Geological Survey, Champaign, IL (United States); Snoeyink, V.L.; Feizoulof, C.; Assanis, D.N.; Syrimis, M. [Illinois Univ., Urbana, IL (United States); Fatemi, S.M. [Amoco Research Center, Naperville, IL (United States)

    1992-10-01

    The first step in the envisioned integrated, multi-product approach for utilizing Illinois coal is the production of ultra low-ash coal. Subsequent steps would convert low-ash coal to high-value products through mild gasification, char activation, and oxidation reactions. Approximately eight pounds of low-ash coal has been obtained from the crude reactor slurry produced for us at the University of North Dakota Energy and Environmental Research Center (UNDEERC). After treatment to remove the remaining meta-cresol, this material will be subjected to mild gasification. Low-ash mild gasification char will be activated and a catalyst surface will be added by oxidation. A 20% coal: 80% diesel fuel slurry was tested in cylinder two of a two-cylinder, diesel engine after the necessary modifications in the engine`s fuel injection system were made. Four tests indicated that the coal successfully substitutes for diesel fuel in the slurry. The fuel burns in the cylinder, with slightly improved thermal and combustion efficiency. The tests were performed at 1800 rpm and 2200 rpm and 75% load. The change in the surface properties of Calgon F-400 commercial activated carbon caused by several treatments were examined by X-ray Photoelectron Spectroscopy (XPS).

  9. Application of noncatalytic gas-solid reactions for a single pellet of changing size to the modeling of fluidized-bed combustion of coal char containing sulfur

    Energy Technology Data Exchange (ETDEWEB)

    Rehmat, A.; Saxena, S.C.; Land, R.H.

    1980-09-01

    A mechanistic model is developed for coal char combustion, with sulfur retention by limestone or dolomite sorbent, in a gas fluidized bed employing noncatalytic single pellet gas-solid reactions. The shrinking core model is employed to describe the kinetics of chemical reactions taking place on a single pellet; changes in pellet size as the reaction proceeds are considered. The solids are assumed to be in back-mix condition whereas the gas flow is regarded to be in plug flow. Most char combustion occurs near the gas distributor plate (at the bottom of the bed), where the bubbles are small and consequently the mass transfer rate is high. For such a case, the analysis is considerably simplified by ignoring the bubble phase since it plays an insignificant role in the overall rate of carbon conversion. Bubble-free operation is also encounterd in the turbulent regime, where the gas flow is quite high and classical bubbles do not exist. Formulation of the model includes setting up heat and mass balance equations pertaining to a single particle (1) exposed to a varying reactant concentration along the height of the bed and (2) whose size changes during reaction. These equations are then solved numerically to account for particles of all sizes in the bed in obtaining the overall carbon conversion efficiency and resultant sulfur retention. In particular, the influence on sorbent requirement of several fluid-bed variables such as oxygen concentration profile, particle size, reaction rate for sulfation reaction, and suflur adsorption efficiency are examined.

  10. Influence of reaction conditions and the char separation system on the production of bio-oil from radiata pine sawdust by fast pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun Ju; Park, Young-Kwon; Kim, Joo Sik [Faculty of Environmental Engineering, University of Seoul, 90 Jeonnong-Dong, Dondaemun-Gu, Seoul 130-743 (Korea)

    2008-08-15

    Radiata pine sawdust was pyrolyzed in a bubbling fluidized bed equipped with a char separation system. The influence of the reaction conditions on the production of bio-oil was investigated through the establishment of mass balance, and the examination of the products' chemical and physical characteristics. The optimal reaction temperature for the production of bio-oil was between 673 and 723 K, and the yield was above 50 wt.% of the product. An optimal feed size also existed. In a particle with a size that was less than 0.3 mm, the bio-oil yield decreased due to overheating, which led to gas formation. A higher flow rate and feeding rate were found to be more effective for the production of bio-oil, but did not significantly affect it. The main compounds of bio-oil were phenolics, including cresol, guaiacol, eugenol, benzendiol and their derivatives, ketones, and aldehydes. In addition, high-quality bio-oils, which contained less than 0.005 wt.% of solid, no ash and low concentrations of alkali and alkaline earth metals, were produced due to the char removal system. (author)

  11. Influence of modified biomass char on releases characteristics of volatiles during pyrolysis of cotton stalk%改性生物质炭对棉秆热解挥发分析出特性的影响

    Institute of Scientific and Technical Information of China (English)

    刘慧慧; 邹俊; 邓勇; 杨海平; 王贤华; 陈汉平

    2016-01-01

    The biomass char has an important influence on the release of volatile during the fast pyrolysis processes due to its complex structure features and the presence of inorganic minerals. Furthermore, as inherent catalysts, the large content of salts in biomass promotes the char to react with volatile. Thus this study aims to investigate the influence of char and inorganic salts on the volatile-char interactions. Experiments were conducted on a two-stage system with the same temperature of 500℃. Char pretreatments i.e. acid washing and salts (NaCl, KCl, MgCl2 and FeCl3) impregnating were introduced. Volatile derived from cotton stalk pyrolysis got reaction under the presence of fresh char with different mass. The condensed bio-oil obtained from the pyrolysis with and without the catalysts (cotton stalk char) was characterized by the GC-MS (gas chromatograph - mass spectrometer) analyses. The non-condensed pyrolysis gas via the filter and drier was characterized by the GC. The results indicated that: with the increasing of the mass of cotton stalk char, its ability of promoting the secondary cracking of pyrolysis volatile became stronger. As a result, the liquid bio-oil yield decreased from 56.70% to 51.32%, while the yield of small molecular gases continued to increase from 17.88% to 22.13%. When the dosage of the cotton stalk char was 2.0 g, the highest gas yield of 22.1% was obtained. When the cotton stalk char was added in the pyrolysis, the acids, aldehydes and lipid content declined sharply. It is deduced that the cotton stalk char plays an inhibiting effect in the formation of them. At the same time, this inhibiting effect is conducive to the formation of more phenols. After deliming, semi-coke group structure will weaken the inhibition of the formation of acids in the volatile. Likewise, the capacity of phenolic enrichment is also reduced. The cotton stalk loaded with metal chloride enhanced the semi-coke’s effects on the volatile catalytic cracking and

  12. Gasification rea ctivity of biomass char with oxygen carrier CuO%生物质半焦/铜基载氧体气化反应特性研究

    Institute of Scientific and Technical Information of China (English)

    冉景煜; 张松; 秦昌雷; 禹建功; 付范萱; 杨琳

    2014-01-01

    Ca lculations of reactions between biomass char and oxygen carriersC uOw ere conducted via the method of Gibbs free energy minimization.The effect of temperature, mass ration of oxygen carrier/biomass char and pressure on the gasification of biomass char was examined. The reactions were experimetn ally investigated usinght ermogravimetric analysis and scanning electron microscopy (SEM).The results show that when using CuO as oxygen carrier in chemical looping gasification ( CLG) of biomass char, the conversion rate of biomass char is improved with increasing reaction temperature.The oxygen carrier CuO starts to sinter when the raect ion temperature is above 750℃.The ad dition of ox ygen carrier has the best enhancement on the CLG of biomass char with mass ratio of biomass char/CuO being 1∶6.It is also found that the increase of rae ction pressure would inhibit the CLG fo biomass chars.%通过吉布斯自由能最小化法对生物质半焦与载氧体CuO之间的反应进行热力学计算,研究温度、载氧体量及压力对生物质半焦化学链气化的影响。同时采用热重分析及扫描电镜等技术手段对生物质半焦/载氧体CuO的反应特性进行了实验研究。结果表明,载氧体CuO能有效促进生物质半焦的气化,随着反应温度的升高,生物质半焦气化效率提高,但当温度超过750℃,CuO载氧体开始出现烧结现象;其半焦/载氧体CuO的化学链气化最佳质量比为1∶6。研究也发现,反应压力的增加对生物质半焦的化学链气化有一定的抑制作用。

  13. Characterization of biomass char and its mercury adsorption performance%生物质焦的表征及其吸附烟气中汞的研究

    Institute of Scientific and Technical Information of China (English)

    尹建军; 段钰锋; 王运军; 王卉; 冒咏秋; 韦红旗

    2012-01-01

    选用四种生物质即稻杆(RS)、稻壳(RH)、松木屑(WC)和棉花杆(CS)制备了生物质焦,利用N2吸附/脱附和傅里叶变换红外光谱(FT-IR)仪,对制备的生物质焦的孔隙结构和表面化学性质进行了表征,分析生物质种类和制焦条件对生物质焦性质的影响.在固定床汞吸附实验台上研究了生物质焦的脱汞性能.结果表明,随着热解温度的升高,生物质焦的比表面积、微孔容积、分形维数等参数有先增大后减小的趋势.WC600、RS600、RH600均有较好的孔结构特性;热解温度升高,生物质焦表面官能团的数量和种类随之减少.不同生物质制备的焦样表面官能团的数量和种类差异较大.其中,RH600和RS600的表面官能团的种类比较丰富,而且含量相对较多.但WC600和CS600表面的官能团种类和数量都很少.生物质焦的单位汞吸附容量与其分形维数以及微孔容积之间并非简单的依附关系,其吸附能力还受含氧官能团等其他因素的影响.%Four biomass of rice straw (RS), rice husk (RH), wood chips (WC) and cotton straw (CS) were chosen to prepare biomass chars which characterized by nitrogen adsorption/desorption and Fourier transform infrared spectroscopy (FT-IR). The influence of biomass type and pyrolysis temperature on pore structure and surface chemical properties of the chars was investigated. Mercury adsorption experiments were carried out in a fixed-bed reactor. The results show that specific surface area, micro-pore volume and fractal dimension of the biomass chars increase firstly and then decrease with increase of the pyrolysis temperature. With the pyrolysis temperature increasing, both the quantity and sorts of the superficial functional groups on the biomass chars reduce and they are dependent greatly on the biomass sorts. Both the superficial functional groups and contents of RH600 and RS600 are more abundant than that of WC600 and CS600. It is not simply direct

  14. 生物质热解焦对模拟烟气中汞吸附特性的实验研究%Experimental Study of Mercury Adsorption Characteristics of Biomass-pyrolysis Chars in the Simulated Flue Gas

    Institute of Scientific and Technical Information of China (English)

    树童; 王秦超; 卢平

    2012-01-01

    Different kinds of biomass-pyrolysis chars were prepared from four kinds of biomass named mulberry twig (MT) , nut shell (NS) , wheat straw (WS) , and rice husk (RH) in a fixed-bed pyrolysis reactor. The specific surface areas and pore structure parameters were measured by a surface area analyzer. The mercury adsorption characteristics of the biomass-pyrolysis chars were carried out in a fixed-bed adsorption reactor. The effects of biomass type, pyrolysis temperature, adsorption temperature and initial mercury concentration on mercury adsorption characteristics were investigated. The results indicated that: ( 1 ) At the same conditions of pyrolysis and adsorption reaction, the adsorption char- acteristics of NS char were the best, MT char and WS chars were in middle, and RS char was the worst. (2) At the py- rolysis temperatures of 400℃- 600℃, biomass chars pyrolyzed at 600℃ showed the best adsorption characteristics, and biomass chars pyrolyzed at 400℃ performed the worst adsorption characteristics. ( 3 ) The unit mercury adsorption capacity of biomass-pyrolysis chars decreased with increasing the adsorption temperature significantly at the adsorption temperature of 60℃-120℃. (4) The unit adsorption capacity of biomass-pyrolysis chars decreased slightly with increasing initial mercury concentration at the initial mercury concentration of 13.5 μg/m3 - 38.1 μg/m3.%以桑树枝、核桃壳、麦秆和稻秆4种生物质为原料,利用固定床热解实验台制备不同的生物质热解焦,采用比表面积与孔隙度分析仪测量了生物质热解焦的比表面积及其孔隙结构参数.利用固定床吸附实验装置,研究了生物质种类、热解温度、吸附温度及汞初始浓度等因素对模拟烟气中汞吸附性能的影响.结果表明:(1)在相同的热解和吸附条件下,核桃壳热解焦的吸附效果最好,其次是桑树枝热解焦和麦秆热解焦,稻秆热

  15. Enantiomer-specific biomagnification of alpha-hexachlorocyclohexane and selected chiral chlordane-related compounds within an Arctic marine food web.

    Science.gov (United States)

    Hoekstra, Paul F; O'Hara, Todd M; Karlsson, Heidi; Solomon, Keith R; Muir, Derek C

    2003-10-01

    Concentrations of achiral and chiral organochlorine contaminants (OCs), including hexachlorocyclohexane isomers (HCH), chlordane congeners (cis- and trans-chlordane, cis- and trans-nonachlor, MC5, MC7, and U82), and related metabolites (oxychlordane [OXY] and heptachlor exo-epoxide [HEPX]), were quantified in seawater (100 L; n = 6) and biota from the coastal Beaufort-Chukchi Seas food web near Barrow (AK, USA). The biota included zooplankton (Calanus spp.; n = 5), fish species such as arctic cod (Boreogadus saida; n = 10), arctic char (Salvelinus alpinus; n = 3), and marine mammals including bowhead whales (Balaena mysticetus; liver: n = 23; blubber: n = 40), beluga whales (Delphinapterus leucas; blubber: n = 20), ringed seals (Phoca hispida; blubber: n = 20), and bearded seals (Erignathus barbatus; blubber: n = 7). The food web magnification factors (FWMFs) for HCHs and chlordane compounds ranged from 0.5 (gamma-HCH) to 6.5 (HEPX) and were expected based on known recalcitrance and biotransformation of OCs. The enantiomer fractions (EFs) of all chiral OCs were near racemic (EF = 0.50) in the seawater, zooplankton, and all fish analyzed. In contrast, the EFs for most OCs analyzed were nonracemic (EF # 0.50) in the marine mammals blubber (range: 0.09-0.79) because of enantiomer-specific biotransformation and (or) accumulation. However, EF values were not significantly correlated with isotopically determined trophic level. The EFs for all chiral OCs (except alpha-HCH) in bowhead whale liver closely approximated the values in zooplankton, suggesting that the accumulation of chiral OCs from prey into this cetacean is not enantiomer specific. However, the modification of EFs from bowhead liver to blubber suggests that this species has the ability to enantioselectively biotransform and accumulate several chiral OC compounds.

  16. Risk Assessment-Led Characterisation of the SiteChar UK North Sea Site for the Geological Storage of CO2

    Directory of Open Access Journals (Sweden)

    Akhurst Maxine

    2015-04-01

    Full Text Available Risk assessment-led characterisation of a site for the geological storage of CO2 in the UK northern North Sea was performed for the EU SiteChar research project as one of a portfolio of sites. Implementation and testing of the SiteChar project site characterisation workflow has produced a ‘dry-run’ storage permit application that is compliant with regulatory requirements. A site suitable for commercial-scale storage was characterised, compatible with current and future industrial carbon dioxide (CO2 sources in the northern UK. Pre-characterisation of the site, based on existing information acquired during hydrocarbon exploration and production, has been achieved from publicly available data. The project concept is to store captured CO2 at a rate of 5 Mt per year for 20 years in the Blake Oil Field and surrounding Captain Sandstone saline aquifer. This commercial-scale storage of 100 Mt CO2 can be achieved through a storage scenario combining injection of CO2 into the oil field and concurrent water production down-dip of the field. There would be no encroachment of supercritical phase CO2 for more than two kilometres beyond the field boundary and no adverse influence on operating hydrocarbon fields provided there is pressure management. Components of a storage permit application for the site are presented, developed as far as possible within a research project. Characterisation and technical investigations were guided by an initial assessment of perceived risks to the prospective site and a need to provide the information required for the storage permit application. The emphasis throughout was to reduce risks and uncertainty on the subsurface containment of stored CO2, particularly with respect to site technical performance, monitoring and regulatory issues, and effects on other resources. The results of selected risk assessment-led site characterisation investigations and the subsequent risk reassessments are described together with their

  17. Measurement of gas species, temperatures, char burnout, and wall heat fluxes in a 200-MW{sub e} lignite-fired boiler at different loads

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhengqi; Jing, Jianping; Liu, Guangkui; Chen, Zhichao; Liu, Chunlong [School of Energy Science and Engineering, Harbin Institute of Technology, 92, West Dazhi Street, Harbin 150001 (China)

    2010-04-15

    We measured various operational parameters of a 200-MW{sub e}, wall-fired, lignite utility boiler under different loads. The parameters measured were gas temperature, gas species concentration, char burnout, component release rates (C, H and N), furnace temperature, heat flux, and boiler efficiency. Cold air experiments of a single burner were conducted in the laboratory. A double swirl flow pulverized-coal burner has two ring recirculation zones that start in the secondary air region of the burner. With increasing secondary air flow, the air flow axial velocity increases, the maximum values for the radial velocity, tangential velocity, and turbulence intensity all increase, and there are slight increases in the air flow swirl intensity and the recirculation zone size. With increasing load gas, the temperature and CO concentration in the central region of burner decrease, while O{sub 2} concentration, NO{sub x} concentration, char burnout, and component release rates of C, H, and N increase. Pulverized-coal ignites farther into the burner, in the secondary air region. Gas temperature, O{sub 2} concentration, NO{sub x} concentration, char burnout and component release rates of C, H, and N all increase. Furthermore, CO concentration varies slightly and pulverized-coal ignites closer. In the side wall region, gas temperature, O{sub 2} concentration, and NO{sub x} concentration all increase, but CO concentration varies only slightly. In the bottom row burner region the furnace temperature and heat flux increase appreciably, but the increase become more obvious in the middle and top row burner regions and in the burnout region. Compared with a 120-MW{sub e} load, the mean NO{sub x} emission at the air preheater exits for 190-MW{sub e} load increases from 589.5 mg/m{sup 3} (O{sub 2} = 6%) to 794.6 mg/m{sup 3} (O{sub 2} = 6%), and the boiler efficiency increases from 90.73% to 92.45%. (author)

  18. 脱灰生物质焦的催化气化反应及动力学%Catalytic gasification reaction and kinetics of deashing biomass char

    Institute of Scientific and Technical Information of China (English)

    张建良; 李净; 胡正文; 付亚清; 左海滨

    2013-01-01

    The physical structure and chemical composition of deashing biomass char coated with potash, as well as its gasification reaction with CO2 were investigated by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometry (EDS) and thermal gravimetry. Experimental data were processed with both the homogeneous model and the shrinking unreacted-core model, and kinetic parameters were obtained for the gasification reaction. It is found that there is an obvious catalytic effect of potash on the gasification reaction. This catalysis improves the overall reaction rate and shortens the reaction time. As the potash content increases from 0%to 4%, more adhering catalytic points, rich in kalium, can be detected on the biomass char surface, and the activation energy of the gasification reaction decreased gradually with increasing potash content. Compared with the shrinking unreacted-core model, the homegeneous model is more suitable for describing the gasification reaction of deashing biomass char with CO2 due to its extremely low ash content.%利用扫描电镜-能谱仪及热重分析仪研究了添加钾盐催化剂的脱灰生物质焦的物理结构、化学成分及其与CO2的气化反应,并分别采用均相模型和收缩未反应核模型对实验数据进行处理,得到动力学参数。研究发现钾盐对脱灰生物质焦-CO2气化反应有明显催化作用,可提高整体反应速率,并减少反应时间。随着钾盐的增加(质量分数在0%∼4%的范围内),附着在生物质焦表面的富钾催化点增多,催化作用逐渐增大,反应的活化能逐渐降低。由于(脱灰)生物质焦的灰分含量很低,与未反应核模型相比,均相模型更适合于描述生物质焦-CO2的气化反应过程。

  19. EXPERIMENTAL RESEARCH ON TAR CATALYTIC CRACKING OVER BIOMASS CHAR%生物质炭催化裂解焦油的实验研究

    Institute of Scientific and Technical Information of China (English)

    尤占平; 由世俊; 李宪莉; 郝长生; 焦永刚

    2011-01-01

    通过实验方法研究了生物质炭对生物质热解焦油的催化特性.通过分析焦油裂解率在催化剂及其重量、蒸汽加入量和加入方式、氮气流量等条件下的变化可知:在蒸汽条件下,生物质炭对焦油有显著的催化裂解效果,最高焦油转化率可达96.1%.通过对实验条件下裂解产物、裂解气体积分数的分析可知,生物质炭和蒸汽可以促进热解产物里面的可凝结相转化为不可凝结的气体,并且导致气体组分体积分数的变化.裂解气中氢气产量增加较快,最高可达裂解气体积的50.2%.%The catalytic pyrolysis characteristics of biomass char on tar from biomass pyrolysis were studied by experiments. Through analyzing the change of tar conversion rate under conditions like catalyst and its weight, amount and adding methods of steam, nitrogen flow etc, conclusion can be drawn that biomass char has remarkable effects in tar catalytic cracking under steam conditions. The maximum tar conversion rate can be of 96.1%. Through the studies of pyrolysis yields and volume fraction of pyrolysis gas under experimental conditions, it can be known that biomass char and steam can promote condensable liquid changing into uncondensable gas and lead to volume fraction changes of pyrolysis gas composition. The yield of hydrogen increases rapidly with the maximum output up to 50.2% of pyrolysis gas volume.

  20. A first step towards identification of tannin-derived black carbon: Conventional pyrolysis (Py–GC–MS) and thermally assisted hydrolysis and methylation (THM–GC–MS) of charred condensed tannins

    NARCIS (Netherlands)

    Kaal, J.; Nierop, K.G.J.; Kraal, P.; Preston, C.M.

    2012-01-01

    Tannins account for a significant proportion of plant biomass and are likely to contribute to the residues formed by incomplete biomass combustion (black carbon, BC). Nonetheless, the molecular properties of thermally modified tannins have not been investigated in laboratory charring experiments. We