WorldWideScience
1

Pt/Al?O?-catalytic deoxygenation for upgrading of Leucaena leucocephala-pyrolysis oil.  

Science.gov (United States)

The aim of this study was to improve the quality of bio-oil produced from the pyrolysis of Leucaena leucocephala trunks via catalytic deoxygenation using Pt/Al2O3 (Pt content=1.32% (w/w)). The minimum molar ratio of oxygen/carbon (O/C) at 0.14 was achieved when the amount of catalyst was 10% (w/w, bio-oil) and was applied under 4 bar of initial nitrogen pressure at 340C for 1h. The reaction mechanism of the catalytic deoxygenation, in terms of reforming, water-gas shift and dehydration reactions, was proposed. To consider the effect of different biomass types on the efficiency of catalytic deoxygenation, the bio-oils obtained from the pyrolysis of sawdust, rice straw and green microalgae were likewise evaluated for direct comparison. PMID:23648762

Payormhorm, Jiraporn; Kangvansaichol, Kunn; Reubroycharoen, Presert; Kuchonthara, Prapan; Hinchiranan, Napida

2013-07-01

2

Thermal deoxygenation of graphite oxide at low temperature  

Science.gov (United States)

Synthesis of graphene via the deoxygenation of the graphite oxide (GO) is a method for the large-scale production of this nanomaterial possessing exceptional mechanical, electrical and translucent properties. Graphite oxide sheet contains at least four different oxygen atoms connected to the Csp3 and Csp2 atoms of the sheet in the form of hydroxyl, epoxy, carboxyl or carbonyl groups. Some of these functional groups are located at the surface but others situated at the edges of the platelets. To obtain the graphene nanoplatelets or the few-layer graphene the oxygen functionalities must be removed. Exfoliation and deoxygenation can be accomplished by the use of chemical reductants or heat. Thermal deoxygenation as greener and simpler approach is more preferable over chemical reduction approach. Usually a considerable mass loss of GO observed upon heating at temperatures starting at 200 C and is attributed to the deoxygenation process. In order to avoid the defects of the obtained graphene sheets it is very important to find the methods for lowering the deoxygenation temperature of GO. Herein, we have investigated the way treatment of the Hummer's synthesis product with acetone and methyl tert-butyl ether under ultrasonication in order to lower the thermal stability of the graphite oxide and its deoxygenation temperature. The obtained results indicate that treatment of the graphite oxide with solvents mentioned above substantially reduces the reduction and exfoliation temperature (130 C) under ambient atmosphere. The investigation of the composition of evolved gases by hyphenated Pyr/GC/MS method at different experimental conditions under helium atmosphere shows that without the expected H2O, CO and CO2 also sulphur dioxide and acetone has been released.

Kampars, V.; Legzdina, M.

2015-03-01

3

EPR study of deoxygenated high-temperature superconductors  

International Nuclear Information System (INIS)

High-Tc superconductors are EPR silent but on a little deoxygenation of the high-Tc materials and their constituents, they yield rich but complex spectra. Spectra of (1) CuO, (2) BaCuO2, (3) CaCuO2, (4) Y2Cu2O5, (5) La2CuO4, (6) La2-xMxCuO4 (M = Sr, Ba), (7)Y based-123, (8)Bi based-2201, 2212, 2223, (9) Tl based-2223 and (10) Hg based-1212,1223 have been studied. One thing common to all these materials is the CuO2 plane which gets fragmented on deoxygenation and the inherent antiferromagnetic coupling is partially destroyed which results in the appearance of the spectra. Very big fragments do not give any spectra because the original AF order probably remains intact in them. It is expected that when the fragments become magnetically isolated from the bulk, they produce EPR spectra. Most of the spectra have been analyzed and their spin-Hamiltonian parameters determined. The spectra of these species vary a little in terms of g-value and fine-structure splitting constant from sample to sample or even in the same sample and this may be attributed to some extra oxygen attachments retained with these species. Most frequently occurring species is the Cu-tetramer, (CuO)4. As (CuO)4 represents the unit cell of the all important two-dimensional CuO2 plane of the high- Tc materials, its spectra igh- Tc materials, its spectra have been argued to provide some clue to the mechanism of high-Tc superconductivity. The tetramer (CuO)4 is a four one-half spin system and is essentially 16-fold degenerate by Heisenberg isotropic exchange, it is split into 6 components: one pentet, three triplets and two singlets. In superconductors the pentet appears to be the ground state and in the non-superconducting constituents the singlets seem to form the ground state as revealed by the temperature variation studies. In the case of La1.854Sr0.146CuO4 we have found the signature of quantum stripe formation. The high-Tc superconductivity theories involving spin bag, anti ferromagnetic spin fluctuations and magnons can be explained on the basis of Cu-tetramers

4

Low-temperature, selective catalytic deoxygenation of vegetable oil in supercritical fluid media.  

Science.gov (United States)

The effects of supercritical fluids on the production of renewable diesel-range hydrocarbons from natural triglycerides were investigated. Various supercritical fluids, which included CO2 (scCO2 ), propane (scC3 H8 ) and n-hexane (scC6 H14 ), were introduced with H2 and soybean oil into a fixed-bed reactor that contained pre-activated CoMo/?-Al2 O3 . Among these supercritical fluids, scC3 H8 and scC6 H14 efficiently allowed the reduction of the reaction temperature by as much as 50 C as a result of facilitated heat and mass transfer and afforded similar yields to reactions in the absence of supercritical fluids. The compositional analyses of the gas and liquid products indicated that the addition of scC3 H8 during the hydrotreatment of soybean oil promoted specific deoxygenation pathways, decarbonylation and decarboxylation, which consumed less H2 than the hydrodeoxygenation pathway. As a result, the quantity of H2 required to obtain a high yield of diesel-range hydrocarbons could be reduced to 57 % if scC3 H8 was used. As decarboxylation and decarbonylation are mildly endothermic reactions, the reduced heat transfer resistance in scC3 H8 may drive the deoxygenation reaction to thermodynamically favourable pathways. PMID:24339322

Kim, Seok Ki; Lee, Hong-Shik; Hong, Moon Hyun; Lim, Jong Sung; Kim, Jaehoon

2014-02-01

5

Pyrolysis of biomass. Rapid pyrolysis at high temperature. Slow pyrolysis for active carbon preparation.  

OpenAIRE

Pyrolysis of biomass consists of heating solid biomass inthe absence of air to produce solid, liquid and gaseous fuels.In the first part of this thesis rapid pyrolysis of wood(birch) and some agricultural residues (olive waste, sugarcanebagasse and wheat straw in untreated and in pelletized form) athigh temperature (800C?1000C) is studied ina free fall reactor at pilot scale. These conditions are ofinterest for gasification in fluidized beds. Of main interestare the gas and char yields a...

Zanzi, Rolando

2001-01-01

6

Experimental study on low temperature pyrolysis of forestry residues  

Energy Technology Data Exchange (ETDEWEB)

Biomass low temperature pyrolysis is a thermo-chemical treatment method that is earmarked by an pyrolysis temperature ranging from 200 to 300 C (under anoxic, heating rates {<=} 50 C/min). This paper investigates the low temperature pyrolysis properties of the raw biomass, including mulberry branch and wood chips, which collected from Jiangsu, China was carried out in a self-designed continuous pyrolysis facility. The experiments were carried out at pyrolysis temperatures of 250 {proportional_to} 300 C and residence time of 10 {proportional_to} 30 min. The results show that the mass yield of mulberry branch charcoal decreased with the increasing of the pyrolysis temperature and residence time, and the pyrolysis temperature has a significant effect on low temperature pyrolysis than the residence time. The fixed carbon and elemental carbon content of the biomass charcoals increased and volatile matters, hydrogen and oxygen contents of biomass charcoals decreased with the increasing of the pyrolysis temperature and residence time, which results in the decreasing of H/C and O/C ratios. The energy density continues to increase with increase in the pyrolysis temperature and residence time. After the pre-treatment, the biomass charcoal compared with raw biomass gained a high energy density and the improvement of hydrophobicity (OH groups are responsible for hydrogen bonding with water). SEM micrographs of mulberry branch and mulberry branch charcoals show that the porosity and the degree of thermal degradation increase with increasing of the pyrolysis temperature. After based on a systematic consideration, the operating condition of 275 C and 10 min was recommended.

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

2013-07-01

7

Theoretical Study of the Thermal Decomposition of Carboxylic Acids at Pyrolysis Temperature  

Energy Technology Data Exchange (ETDEWEB)

Carboxylic acids are important in the processing of biomass into renewable fuels and chemicals. They are formed from the pretreatment and pyrolysis of hemicellulose biopolymers and are released from the decomposition of sugars. They result from the deconstruction of polyhydroxyalkanoates (bacterial carbon storage polymers) from fatty acids derived from algae, bacteria, and oil crops. The thermal deoxygenation of carboxylic acids is an important step in the conversion of biomass into aliphatic hydrocarbons suitable for use in renewable biofuels and as petrochemical replacements. Decarboxylation, a primary decomposition pathway under pyrolysis conditions, represents an ideal conversion process, because it eliminates two atoms of oxygen for every carbon atom removed. Problematically, additional deoxygenation processes exist (e.g. dehydration) that are in direct competition with decarboxylation and result in the formation of reactive and more fragmented end products. To better understand the competition between decarboxylation and other deoxygenation processes and to gain insight into possible catalysts that would favor decarboxylation, we have investigated the mechanisms and thermochemistry of the various unimolecular and bimolecular deoxygenation pathways for a family of C1-C4 organic acids using electronic structure calculations at the M06-2X/6-311++G(2df,p) level of theory.

Clark, J. M.; Robichaud, D. J.; Nimlos, M. R.

2013-01-01

8

Pressurized pyrolysis of rice husk in an inert gas sweeping fixed-bed reactor with a focus on bio-oil deoxygenation.  

Science.gov (United States)

The pyrolysis of rice husk was conducted in a fixed-bed reactor with a sweeping nitrogen gas to investigate the effects of pressure on the pyrolytic behaviors. The release rates of main gases during the pyrolysis, the distributions of four products (char, bio-oil, water and gas), the elemental compositions of char, bio-oil and gas, and the typical compounds in bio-oil were determined. It was found that the elevation of pressure from 0.1MPa to 5.0MPa facilitated the dehydration and decarboxylation of bio-oil, and the bio-oils obtained under the elevated pressures had significantly less oxygen and higher calorific value than those obtained under atmospheric pressure. The former bio-oils embraced more acetic acid, phenols and guaiacols. The elevation of pressure increased the formation of CH4 partially via the gas-phase reactions. An attempt is made in this study to clarify "the pure pressure effect" and "the combined effect with residence time". PMID:25463787

Qian, Yangyang; Zhang, Jie; Wang, Jie

2014-12-01

9

Ecotoxicological characterization of biochars: role of feedstock and pyrolysis temperature.  

Science.gov (United States)

Seven contrasting feedstocks were subjected to slow pyrolysis at low (300 or 350C) and high temperature (550 or 600C), and both biochars and the corresponding feedstocks tested for short-term ecotoxicity using basal soil respiration and collembolan reproduction tests. After a 28-d incubation, soil basal respiration was not inhibited but stimulated by additions of feedstocks and biochars. However, variation in soil respiration was dependent on both feedstock and pyrolysis temperature. In the last case, respiration decreased with pyrolysis temperature (r=-0.78; ppyrolysis temperature. Strong inhibition was only observed in uncharred food waste and resulting biochars. Inhibition effects were probably linked to high soluble Na and NH4 concentrations when both feedstocks and biochars were considered, but mostly to soluble Na when only biochars were taken into account. The general lack of toxicity of the set of slow pyrolysis biochars in this study at typical field application rates (?20 Mg ha(-1)) suggests a low short-term toxicity risk. At higher application rates (20-540 Mg ha(-1)), some biochars affected collembolan reproduction to some extent, but only strongly in the food waste biochars. Such negative impacts were not anticipated by the criteria set in currently available biochar quality standards, pointing out the need to consider ecotoxicological criteria either explicitly or implicitly in biochar characterization schemes or in management recommendations. PMID:25647370

Domene, X; Enders, A; Hanley, K; Lehmann, J

2015-04-15

10

Pyrolysis temperature influences ameliorating effects of biochars on acidic soil.  

Science.gov (United States)

The biochars were prepared from straws of canola, corn, soybean, and peanut at different temperatures of 300, 500, and 700 C by means of oxygen-limited pyrolysis.Amelioration effects of these biochars on an acidic Ultisol were investigated with incubation experiments, and application rate of biochars was 10 g/kg. The incorporation of these biochars induced the increase in soil pH, soil exchangeable base cations, base saturation, and cation exchange capacity and the decrease in soil exchangeable acidity and exchangeable Al. The ameliorating effects of biochars on acidic soil increased with increase in their pyrolysis temperature. The contribution of oxygen-containing functional groups on the biochars to their ameliorating effects on the acidic soil decreased with the rise in pyrolysis temperature, while the contribution from carbonates in the biochars changed oppositely. The incorporation of the biochars led to the decrease in soil reactive Al extracted by 0.5mol/L CuCl2, and the content of reactive Al was decreased with the increase in pyrolysis temperature of incorporated biochars. The biochars generated at 300 C increased soil organically complexed Al due to ample quantity of oxygen-containing functional groups such as carboxylic and phenolic groups on the biochars, while the biochars generated at 500 and 700 C accelerated the transformation of soil exchangeable Al to hydroxyl-Al polymers due to hydrolysis of Al at higher pH. Therefore, the crop straw-derived biochars can be used as amendments for acidic soils and the biochars generated at relatively high temperature have great ameliorating effects on the soils. PMID:24078274

Wan, Qing; Yuan, Jin-Hua; Xu, Ren-Kou; Li, Xing-Hui

2014-02-01

11

Catalytic pyrolysis of palm kernel shell waste in a fluidized bed.  

Science.gov (United States)

The catalytic pyrolysis of palm kernel shell was investigated in a fluidized bed with zsm-5 and equilibrium FCC (Ecat) catalysts. Catalytic pyrolysis oil yields were remarkably reduced and gas yields were increased due to the higher catalytic reaction of primary volatiles compared to non-catalytic pyrolysis. Char yields were affected by temperature and the pore structure of the catalysts. The pyrolysis oil was characterized by lower H/C and O/C molar ratios due to aromatization and deoxygenation of volatiles by the catalysts. The catalytic pyrolysis oils contained more oxygen and nitrogen and less sulfur than petroleum oils. The oils had a high concentration of nitriles, with a carbon number distribution similar to fatty acids. The catalytic pyrolysis oils featured high nitriles yield with Ecat and high aromatics yield in the light fraction with zsm-5, due to characteristics of the catalyst. The catalytic pyrolysis oils showed potentials as feedstocks for bio-diesel and chemicals. PMID:25006017

Kim, Sung Won; Koo, Bon Seok; Lee, Dong Hyun

2014-09-01

12

Deoxygenation of methanol over ZSM-5 in a high-pressure catalytic pyroprobe  

Energy Technology Data Exchange (ETDEWEB)

Deoxygenation is a critical step in making hydrocarbon-rich biofuels from biomass constituents. Although the thermal effects of oxygenate aromatization have been widely reported, the effect of pressure on this critical reaction has not yet been closely investigated, one primary reason being the unavailability of a reactor that can pyrolyze oxygenates, especially those in solid form, under pressurized conditions. Here, the first of a series of studies on how oxygenates behave when catalytically pyrolyzed under elevated pressure and temperature conditions is reported. Methanol, the simplest alcohol, was selected as the candidate to study the chemical phenomena that occur under pressurized catalytic pyrolysis. The reactions were carried out over the shape-selective catalyst ZSM-5 (SiO{sub 2}/Al{sub 2}O{sub 3}=30) under varying pressure (0 to 2.0684 MPa (300 psi) in 0.3447 MPa (50 psi) increments) and temperature (500 to 800 C in 50 C increments) conditions. Benzene, toluene, ethyl benzene, and xylenes (BTEX) were analyzed as the deoxygenated products of the reaction. The results indicate that the reactor pressure significantly affects deoxygenated product composition. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Gunawardena, D.A.; Fernando, S.D. [Texas A and M University, Department of Biological and Agricultural Engineering, College Station, TX (United States)

2011-02-15

13

Effects of pyrolysis temperature and heating time on biochar obtained from the pyrolysis of straw and lignosulfonate.  

Science.gov (United States)

In this study, the effects of pyrolysis temperature and heating time on the yield and physicochemical and morphological properties of biochar obtained from straw and lignosulfonate were investigated. As pyrolysis temperature increased, pH, ash content, carbon stability, and total content of carbon increased while biochar yield, volatile matter, total content of hydrogen, oxygen, nitrogen and sulfur decreased. The data from scanning electron microscope image and nuclear magnetic resonance spectra indicated an increase in porosity and aromaticity of biochar produced at a high temperature. The results showed that feedstock types could also influence characteristics of the biochar with absence of significant effect on properties of biochar for heating time. PMID:25435066

Zhang, Jie; Liu, Jia; Liu, Rongle

2015-01-01

14

Characterization of slow pyrolysis biochars: effects of feedstocks and pyrolysis temperature on biochar properties.  

Science.gov (United States)

Biochars are increasingly used as soil amendment and for C sequestration in soils. The influence of feedstock differences and pyrolysis temperature on biochar characteristics has been widely studied. However, there is a lack of knowledge about the formation of potentially toxic compounds that remain in the biochars after pyrolysis. We investigated biochars from three feedstocks (wheat straw, poplar wood, and spruce wood) that were slowly pyrolyzed at 400, 460, and 525C for 5 h (straw) and 10 h (woodchips), respectively. We characterized the biochars' pH, electrical conductivity, elemental composition (by dry combustion and X-ray fluorescence), surface area (by N adsorption), water-extractable major elements, and cation exchange capacity (CEC). We further conducted differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffractometry to obtain information on the biochars' molecular characteristics and mineralogical composition. We investigated trace metal content, total polycyclic aromatic hydrocarbon (PAH) content, and PAH composition in the biochars. The highest salt (4.92 mS cm) and ash (12.7%) contents were found in straw-derived biochars. The H/C ratios of biochars with highest treatment temperature (HTT) 525C were 0.46 to 0.40. Surface areas were low but increased (1.8-56 m g) with increasing HTT, whereas CEC decreased (162-52 mmol kg) with increasing HTT. The results of DSC and FTIR suggested a loss of labile, aliphatic compounds during pyrolysis and the formation of more recalcitrant, aromatic constituents. X-ray diffractometry patterns indicated a mineralogical restructuring of biochars with increasing HTT. Water-extractable major and trace elements varied considerably with feedstock composition, with trace elements also affected by HTT. Total PAH contents (sum of EPA 16 PAHs) were highly variable with values up to 33.7 mg kg; irrespective of feedstock type, the composition of PAHs showed increasing dominance of naphthalene with increasing HTT. The results demonstrate that biochars are highly heterogeneous materials that, depending on feedstock and HTT, may be suitable for soil application by contributing to the nutrient status and adding recalcitrant C to the soil but also potentially pose ecotoxicological challenges. PMID:22751041

Kloss, Stefanie; Zehetner, Franz; Dellantonio, Alex; Hamid, Raad; Ottner, Franz; Liedtke, Volker; Schwanninger, Manfred; Gerzabek, Martin H; Soja, Gerhard

2012-01-01

15

Evolution of volatile products from oil shales by temperature-programmed pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Temperature-programmed pyrolysis of Beypazari (Turkey) and Timahdit (Morocco) oil shales was investigated. The maximum product evolution temperatures were determined for each sample. n-Paraffins and 1-olefins in the pyrolysis products were classified by carbon number. The effect of kerogen types on the distribution of n-paraffins and 1-olefins was also investigated. 13 refs., 4 figs., 2 tabs.

Ballice, L.; Yuksel, M.; Saglam, M.; Schulz, H. [University of Ege, Izmir (Turkey). Dept. of Chemical Engineering

1996-03-01

16

MICROSTRUCTURE DEVELOPMENT OF CHARS DERIVED FROM HIGH-TEMPERATURE PYROLYSIS OF BARLEY (HORDEUM VULGARE L.) HULLS  

Science.gov (United States)

Chars derived from pyrolysis of biomass can be a potential source of fuel or a valuable co product. Depending on the pyrolysis time and exposure temperature, the surfaces and interfaces developed can result in their use as physical or chemical absorption or adsorption materials for metals, catalys...

17

A granular-biomass high temperature pyrolysis model based on the Darcy flow  

Science.gov (United States)

We established a model for the chemical reaction kinetics of biomass pyrolysis via the high-temperature thermal cracking of liquid products. We divided the condensable volatiles into two groups, based on the characteristics of the liquid prdoducts., tar and biomass oil. The effects of temperature, residence time, particle size, velocity, pressure, and other parameters on biomass pyrolysis and high-temperature tar cracking were investigated numerically, and the results were compared with experimental data. The simulation results showed a large endothermic pyrolysis reaction effect on temperature and the reaction process. The pyrolysis reaction zone had a constant temperature period in several layers near the center of large biomass particles. A purely physical heating process was observed before and after this period, according to the temperature index curve.

Guan, Jian; Qi, Guoli; Dong, Peng

2015-03-01

18

Formate-assisted pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The present invention provides, among other thing, methods for creating significantly deoxygenated bio-oils form biomass including the steps of providing a feedstock, associating the feedstock with an alkali formate to form a treated feedstock, dewatering the treated feedstock, heating the dewatered treated feedstock to form a vapor product, and condensing the vapor product to form a pyrolysis oil, wherein the pyrolysis oil contains less than 30% oxygen by weight.

DeSisto, William Joseph; Wheeler, Marshall Clayton; van Heiningen, Adriaan R. P.

2015-03-17

19

Microwave and Conventional Pyrolysis of Coffee Hulls at Different Temperatures for a Hydrogen Rich Gas  

OpenAIRE

Microwave and Conventional Pyrolysis of Coffee Hulls at Different Temperatures for a Hydrogen Rich Gas. The paper reports the comparison of using a microwave and a conventional furnace to do the pysolysis of the coffee hulls.

Menendez, Angel; Fernandez, Yolanda; Dominguez, Antonio; Pis, Juan; Valente Nabais, Joao; Carrott, Peter; Carrott, Manuela

2006-01-01

20

Yield and Characteristics of Pyrolysis Products Obtained from Schizochytrium limacinum under Different Temperature Regimes  

Directory of Open Access Journals (Sweden)

Full Text Available Pyrolysis-gas chromatographic mass spectrometry (Py-GC/MS was used to determine the yield and chemical composition of the pyrolysis products of Schizochytrium limacinum. The pyrolysis was carried out by varying the temperature from 300 C to 800 C. It was found that the main decomposition temperature of Schizochytrium limacinum was 428.16 C, at which up to 66.5% of the mass was lost. A further 18.7% mass loss then occurred in a relatively slow pace until 760.2 C due to complete decomposition of the ash content of Schizochytrium limacinum. The pyrolysis of Schizochytrium limacinum at 700 C produced the maximum yield (67.7% of pyrolysis products compared to 61.2% at 400 C. While pollutants released at 700 C (12.3% was much higher than that of 400 C (2.1%. Higher temperature will lead to more pollutant (nitrogen compounds and PAHs release, which is harmful to the environment. Considering the reasonably high yield and minimum release of pollutants, a lower pyrolysis temperature (400 C was found to be optimum for producing biofuel from Schizochytrium limacinum.

Renjie Dong

2013-07-01

21

Cellulose-hemicellulose and cellulose-lignin interactions in wood pyrolysis at gasification temperature  

Energy Technology Data Exchange (ETDEWEB)

Cellulose-hemicellulose and cellulose-lignin interactions during pyrolysis at gasification temperature (800 C) were investigated with various cellulose samples mixed with hemicellulose (glucomannan or xylan) or milled wood lignin. Significant interactions were observed in cellulose-lignin pyrolysis; lignin inhibited the thermal polymerization of levoglucosan formed from cellulose and enhanced the formation of the low molecular weight products from cellulose with reduced yield of char fraction; cellulose reduced the secondary char formation from lignin and enhanced the formation of some lignin-derived products including guaiacol, 4-methyl-guaiacol and 4-vinyl-guaiacol. Comparatively weak interactions were also observed in cellulose-hemicellulose pyrolysis. Finally, factors influencing the wood pyrolysis at gasification temperature are discussed. (author)

Hosoya, T.; Kawamoto, H.; Saka, S. [Graduate School of Energy Science, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

2007-08-15

22

Total recycling of CCA treated wood waste by low-temperature pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

A system to turn a potentially harmful stream of solid waste into a set of substreams with either commercial value or highly concentrated residual streams is presented. The waste which is considered is metal impregnated (in particular Chromated Copper Arsenate (CCA) treated) wood waste and timber, such as telephone poles, railway sleepers, timber from landscape and cooling towers, wooden silos, hpo-poles, cable drums and wooden playground equipment. These waste streams sum up to several 100,000 tons of material per year currently to be dumped in every major country of the european Community (EC). Technologies need to be developed to reduce this CCA treated wood waste, such that all of the metals are contained in a marketable product stream, and the pyrolysis gases and/or pyrolysis liquid are used to their maximum potential with respect to energy recuperation. Pyrolyzing the CCA treated wood waste may be a good solution to the growing disposal problem since low temperatures and no oxidizing agents are used, which result in lower loss of metals compared to combustion. An experimental labscale pyrolysis system has been developed to study the influence of the pyrolysis temperature and the duration of the pyrolysis process on the release of metals and the mass reduction. The macrodistribution and microdistribution of the metals in the solid pyrolysis residue is studied using Inductively coupled Plasma mass Spectrometry (ICP-MS) and Scanning Electron Microscopy coupled with Energy Dispersive X-ray Analysis (SEM-EDXA). Furthermore, a complete mass balance is calculated over the pyrolysis system. Based on these results a semi-industrial pyrolysis system has been developed consisting of three stages: grinding, packed bed pyrolysis and metal separation. Special types of equipment have been developed to carry out the three stages. A new grinding system has been developed, based on a crushing mechanism rather than a cutting mechanism.

Helsen, L.; Bulck, E. van den [Katholieke Univ. Leuven, Heverlee (Belgium). Dept. of Mechanical Engineering; Hery, J.S. [Beaumartin S.A., Gradignan (France)

1998-12-31

23

Catalytic pyrolysis of biomass: Effects of pyrolysis temperature, sweeping gas flow rate and MgO catalyst  

International Nuclear Information System (INIS)

Cotton seed, as a biomass source, is pyrolysed in a tubular fixed-bed reactor under various sweeping gas (N2) flow rates at different pyrolysis temperatures. In the non-catalytic work, the maximum bio-oil yield was attained as 48.30% at 550 oC with a sweeping gas flow rate of 200 mL min-1. At the optimum conditions, catalytic pyrolysis of biomass samples was performed with various amounts of MgO catalyst (5, 10, 15, and 20 wt.% of raw material). Catalyst addition decreased the quantity of bio-oil yet increased the quality of bio-oil in terms of calorific value, hydrocarbon distribution and removal of oxygenated groups. It was observed that increasing the amount of catalyst used, decreased the oil yields while increased the gas and char yields. Bio-oils obtained at the optimum conditions were separated into aliphatic, aromatic and polar sub-fractions. After the application of column chromatography, bio-oils were subjected into elemental, FT-IR and 1H NMR analyses. Aliphatic sub-fractions of bio-oils were analyzed by GC-MS. It was deduced that the fuel obtained via catalytic pyrolysis mainly consisted of lower weight hydrocarbons in the diesel range. Finally, obtained results were compared with petroleum fractions and evaluated as a potential source for liquid fuels.

24

Analytical pyrolysis mass spectrometry: new vistas opened by temperature-resolved in-source PYMS  

Science.gov (United States)

Analytical pyrolysis mass spectrometry (PYMS) is introduced and its applications to the analysis of synthetic polymers, biopolymers, biomacromolecular systems and geomacromolecules are critically reviewed. Analytical pyrolysis inside the ionisation chamber of a mass spectrometer, i.e. in-source PYMS, gives a complete inventory of the pyrolysis products evolved from a solid sample. The temperature-resolved nature of the experiment gives a good insight into the temperature dependence of the volatilisation and pyrolytic dissociation processes. Chemical ionisation techniques appear to be especially suitable for the analysis of oligomeric fragments released in early stages of the pyrolysis of polymer systems. Large oligomeric fragments were observed for linear polymers such as cellulose (pentadecamer), polyhydroxyoctanoic acid (tridecamer) and polyhydroxybutyric acid (heneicosamer). New in-source PYMS data are presented on artists' paints, the plant polysaccharides cellulose and xyloglucan, several microbial polyhydroxyalkanoates, wood and enzyme-digested wood, biodegraded roots and a fossil cuticle of Miocene age. On-line and off-line pyrolysis chromatography mass spectrometric approaches are also discussed. New data presented on high temperature gas chromatography--mass spectrometry of deuterio-reduced permethylated pyrolysates of cellulose lead to a better understanding of polysaccharide dissociation mechanisms. Pyrolysis as an on-line sample pretreatment method for organic macromolecules in combination with MS techniques is a very challenging field of mass spectrometry. Pyrolytic dissociation and desorption is not at all a chaotic process but proceeds according to very specific mechanisms.

Boon, Jaap J.

1992-09-01

25

Fluctuations between conformational substrates in deoxygenated myoglobin  

International Nuclear Information System (INIS)

Nuclear gamma resonace experiments on crystals of deoxygenated sperm whale myoglobin were performed at temperatures between 4.2 K and 300 K. Above 190 K the 2>-values start to increase very rapidly with temperature indicating fluctuation processes between conformational substates within the molecule. Large areas around the iron atom take part in these fluctuations. Below 200 K, the myoglobin molecules become frozen in various conformational substates. Above 200 K, fluctuations with a characteristic time of 10-7s are important. (orig.)

26

Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces  

Science.gov (United States)

The selective deoxygenation of aldehydes and alcohols without cleaving the Csbnd C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or ?2(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo2C, as well as the effect of the furan ring on the selective deoxygenation of the Cdbnd O and Csbnd OH bonds.

Xiong, Ke; Yu, Weiting; Chen, Jingguang G.

2014-12-01

27

A review of the toxicity of biomass pyrolysis liquids formed at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

The scaleup of biomass fast pyrolysis systems to large pilot and commercial scales will expose an increasingly large number of personnel to potential health hazards, especially during the evaluation of the commercial use of the pyrolysis condensates. Although the concept of fast pyrolysis to optimize liquid products is relatively new, low-temperature pyrolysis processes have been used over the aeons to produce charcoal and liquid by-products, e.g., smoky food flavors, food preservatives, and aerosols containing narcotics, e.g., nicotine. There are a number of studies in the historical literature that concern the hazards of acute and long-term exposure to smoke and to the historical pyrolysis liquids formed at low temperatures. The reported toxicity of smoke, smoke food flavors, and fast pyrolysis oils is reviewed. The data found for these complex mixtures suggest that the toxicity may be less than that of the individual components. It is speculated that there may be chemical reactions that take place that serve to reduce the toxicity during aging. 81 refs.

Diebold, J P [Thermalchemie, Inc., Lakewood, CO (United States)

1997-04-01

28

Effect of pyrolysis temperature on composition, surface properties and thermal degradation rates of Brazil Nut shells.  

Science.gov (United States)

Changes in chemical and surface characteristics of Brazil Nut shells (Bertholletia excelsa) due to pyrolysis at different temperatures (350 degrees C, 600 degrees C, 850 degrees C) were examined. For this purpose, proximate and ultimate analyses, physical adsorption measurements of N2 (-196 degrees C) and CO, (25 degrees C) as well as samples visualisation by scanning electronic microscopy (SEM) were performed. Appreciable differences in the residue characteristics, depending markedly on the pyrolysis temperature, were observed. Release of volatile matter led to the development of pores of different sizes. Progressive increases in micropore development with increasing pyrolysis temperature took place, whereas a maximum development of larger pores occurred at 600 degrees C. Furthermore, kinetics measurements of Brazil Nut shells pyrolysis from ambient temperature up to 900 degrees C were performed by non-isothermal thermogravimetric analysis. A model taking into account the significant changes in the residue during pyrolysis, through an increase in the activation energy with temperature and solid conversion, were found to properly fit the kinetics data over the wide range of degradation investigated. PMID:11315805

Bonelli, P R; Della Rocca, P A; Cerrella, E G; Cukierman, A L

2001-01-01

29

Pyrolysis Oil from the Fruit and Cake of Jatropha curcas Produced Using a Low Temperature Conversion (LTC Process: Analysis of a Pyrolysis Oil-Diesel Blend  

Directory of Open Access Journals (Sweden)

Full Text Available Background: The LTC process is a technique that consists of heating solid residues at a temperature of 380oC - 420oC in an inert atmosphere and their products are evaluated individually: these products include pyrolysis oil, pyrolytic char, gas and water. The objective of this study was to compare the effects of the use of oils obtained by pyrolysis of Jatropha curcas as an additive for diesel in different proportions. Results: A Low Temperature Conversion (LTC process carried out on samples of Jatropha curcas fruit and generated pyrolysis oil, pyrolyic char, gas and aqueous fractions in relative amounts of 23, 37, 16 and 14% [w/w] respectively for Jatropha curcas fruit and 19, 47, 12 and 22% [w/w] respectively for Jatropha curcas cake. The oil fractions were analyzed by FTIR, 1H NMR, 13C NMR, GCMS and physicochemical analysis. The pyrolysis oil was added to final concentrations of 2, 5, 10 and 20% [w/w] to commercial diesel fuel. The density, viscosity, sulfur content and flash point of the mixtures were determined. Conclusions: The results indicated that the addition of the pyrolysis oil maintained the mixtures within the standards of the diesel directive, National Petroleum Agency (ANP no 15, of 19. 7. 2006, with the exception of the viscosity of the mixtures containing 20% pyrolysis oil.

Monique Kort-Kamp Figueiredo

2011-07-01

30

The influence of temperature and heating rate on the slow pyrolysis of biomass  

Energy Technology Data Exchange (ETDEWEB)

The slow pyrolysis of biomass in the form of pine wood was investigated in a static batch reactor at pyrolysis temperatures from 300 to 720{sup o}C and heating rates from 5 to 80 K min{sup -1}. The compositions and properties of the derived gases, pyrolytic oils and solid char were determined in relation to pyrolysis temperatures and heating rates. In addition, the wood and the major components of the wood - cellulose, hemicellulose and lignin - were pyrolysed in a thermogravimetric analyser (TGA) under the same experimental conditions as in the static batch reactor. The static batch reactor results showed that as the pyrolysis temperature was increased, the percentage mass of solid char decreased, while gas and oil products increased. There was a small effect of heating rate on product yield. The lower temperature regime of decomposition of wood showed that mainly H{sub 2}O, CO{sub 2} and CO were evolved and at the higher temperature regime, the main decomposition products were oil, H{sub 2}O, H{sub 2}, hydrocarbon gases and lower concentrations of CO and CO{sub 2}. Fourier transformation infra-red spectroscopy and elemental analysis of the oils showed they were highly oxygenated. The TGA results for wood showed two main regimes of weight loss, the lower temperature regime could be correlated with the decomposition of hemicellulose and the initial stages of cellulose decomposition whilst the upper temperature regime correlated mainly with the later stages of cellulose decomposition. Lignin thermal decomposition occurred throughout the temperature range of pyrolysis. (author)

Williams, P.T.; Besler, Serpil [Leeds Univ. (United Kingdom). Dept. of Fuel and Energy

1996-10-01

31

Effects of pyrolysis temperature on the physicochemical properties of empty fruit bunch and rice husk biochars.  

Science.gov (United States)

Biochar has received great attention recently due to its potential to improve soil fertility and immobilize contaminants as well as serving as a way of carbon sequestration and therefore a possible carbon sink. In this work, a series of biochars were produced from empty fruit bunch (EFB) and rice husk (RH) by slow pyrolysis at different temperatures (350, 500, and 650C) and their physicochemical properties were analysed. The results indicate that porosity, ash content, electrical conductivity (EC), and pH value of both EFB and RH biochars were increased with temperature; however, yield, cation exchange capacity (CEC), and H, C, and N content were decreased with increasing pyrolysis temperature. The Fourier transform IR spectra were similar for both RH and EFB biochars but the functional groups were more distinct in the EFB biochar spectra. There were reductions in the amount of functional groups as pyrolysis temperature increased especially for the EFB biochar. However, total acidity of the functional groups increased with pyrolysis temperature for both biochars. PMID:24643171

Claoston, N; Samsuri, A W; Ahmad Husni, M H; Mohd Amran, M S

2014-04-01

32

Trichloroethylene adsorption by pine needle biochars produced at various pyrolysis temperatures.  

Science.gov (United States)

In this study, pine needles were converted to biochar (BC) at different pyrolysis temperatures of 300, 500, and 700 C to sorb trichloroethylene (TCE), and the changes in BC properties with each temperature were evaluated. Pyrolysis temperature showed a pronounced effect on BC properties. Decreases in molar H/C and O/C ratios resulted from removing O- and H-containing functional groups with increasing temperature, and produced high aromaticity and low polarity BCs. BCs produced at higher temperature showed greater TCE removal efficiency from water due to their high surface area, micro-porosity, and carbonized extent. The performance of various BCs for TCE removal was assessed by the Freundlich, Langmuir, Temkin, and Dubinin-Radushkevich adsorption models, among which the Temkin and Dubinin-Radushkevich models best described TCE adsorption onto various BCs, indicating prevailing sorption mechanism as pore-filling. PMID:23838320

Ahmad, Mahtab; Lee, Sang Soo; Rajapaksha, Anushka Upamali; Vithanage, Meththika; Zhang, Ming; Cho, Ju Sik; Lee, Sung-Eun; Ok, Yong Sik

2013-09-01

33

Effects of Feedstock and Pyrolysis Temperature on Biochar Adsorption of Ammonium and Nitrate  

Science.gov (United States)

Biochar produced by pyrolysis of biomass can be used to counter nitrogen (N) pollution. The present study investigated the effects of feedstock and temperature on characteristics of biochars and their adsorption ability for ammonium N (NH4+-N) and nitrate N (NO3?-N). Twelve biochars were produced from wheat-straw (W-BC), corn-straw (C-BC) and peanut-shell (P-BC) at pyrolysis temperatures of 400, 500, 600 and 700C. Biochar physical and chemical properties were determined and the biochars were used for N sorption experiments. The results showed that biochar yield and contents of N, hydrogen and oxygen decreased as pyrolysis temperature increased from 400C to 700C, whereas contents of ash, pH and carbon increased with greater pyrolysis temperature. All biochars could sorb substantial amounts of NH4+-N, and the sorption characteristics were well fitted to the Freundlich isotherm model. The ability of biochars to adsorb NH4+-N followed: C-BC>P-BC>W-BC, and the adsorption amount decreased with higher pyrolysis temperature. The ability of C-BC to sorb NH4+-N was the highest because it had the largest cation exchange capacity (CEC) among all biochars (e.g., C-BC400 with a CEC of 38.3 cmol kg?1 adsorbed 2.3 mg NH4+-N g?1 in solutions with 50 mg NH4+ L?1). Compared with NH4+-N, none of NO3?-N was adsorbed to biochars at different NO3? concentrations. Instead, some NO3?-N was even released from the biochar materials. We conclude that biochars can be used under conditions where NH4+-N (or NH3) pollution is a concern, but further research is needed in terms of applying biochars to reduce NO3?-N pollution. PMID:25469875

Gai, Xiapu; Wang, Hongyuan; Liu, Jian; Zhai, Limei; Liu, Shen; Ren, Tianzhi; Liu, Hongbin

2014-01-01

34

Pyrolysis and gasification of coal at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

The macropore structure of chars is a major factor in determining their reactivity during the gasification stage. The major objectives of this contract were to (a) quantify by direct measurements the effect of pyrolysis conditions of the macropore structure, and (b) establish how the macropores affected the reactivity pattern, the ignition behavior and the fragmentation of the char particles during gasification in the regime of strong diffusional limitations. Results from this project provide much needed information on the factors that affect the quality of the solid products (chars) of coal utilization processes (for example, mild gasification processes). The reactivity data will also provide essential parameters for the optimal design of coal gasification processes. (VC)

Zygourakis, K.

1992-02-10

35

Catalytic pyrolysis of biomass for biofuels production  

Energy Technology Data Exchange (ETDEWEB)

Fast pyrolysis bio-oils currently produced in demonstration and semi-commercial plants have potential as a fuel for stationary power production using boilers or turbines but they require significant modification to become an acceptable transportation fuel. Catalytic upgrading of pyrolysis vapors using zeolites is a potentially promising method for removing oxygen from organic compounds and converting them to hydrocarbons. This work evaluated a set of commercial and laboratory-synthesized catalysts for their hydrocarbon production performance via the pyrolysis/catalytic cracking route. Three types of biomass feedstocks; cellulose, lignin, and wood were pyrolyzed (batch experiments) in quartz boats in physical contact with the catalysts at temperature ranging from 400 C to 600 C and catalyst-to-biomass ratios of 5-10 by weight. Molecular-beam mass spectrometry (MBMS) was used to analyze the product vapor and gas composition. The highest yield of hydrocarbons (approximately 16 wt.%, including 3.5 wt.% of toluene) was achieved using nickel, cobalt, iron, and gallium-substituted ZSM-5. Tests performed using a semi-continuous flow reactor allowed us to observe the change in the composition of the volatiles produced by the pyrolysis/catalytic vapor cracking reactions as a function of the catalyst time-on-stream. The deoxygenation activity decreased with time because of coke deposits formed on the catalyst. (author)

French, Richard; Czernik, Stefan [National Bioenergy Center, National Renewable Energy Laboratory, 1617 Cole Blvd., Golden, CO 80401 (United States)

2010-01-15

36

Preparation of Organic/Inorganic Membrane by PDMS Low-temperature Pyrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available The organic/inorganic membranes were prepared via low-temperature pyrolysis of polymers. Firstly, polymeric membranes were prepared by dip-coating method using PDMS as the precursor and stainless steel as the support. Then they were pyrolyzed at 350-480C under inert atmosphere. The effects of preparation conditions on the gas separation performance of the organic/inorganic membranes were investigated. Chemical structure changes of PDMS in the pyrolysis process were studied by TG and FT-IR. The morphology of organic/inorganic membrane was characterized by SEM. The results showed that the organic/inorganic membranes with good gas separation performance could be successfully prepared by low-temperature pyrolysis of PDMS. The membrane retains part flexibility of PDMS, and presents good thermostability and high gas permselectivity. The gas separation performance and membrane layer structure of organic/inorganic membranes are greatly affected by the preparation conditions such as the PDMS concentration, coating times, pyrolysis temperature and properties of support. The gas separation performances prepared under the optimum condition are that the O2 permeation flux of 21.2 GPU(1 GPU=7.50110-12m3(STP/(m2?s?Pa and O2/N2 selectivity of 2.28.

YU Jiao-Zhu, LI Lin, JIN Xin, DING Ling-Hua, WANG Tong-Hua

2014-02-01

37

Recycling of automobile shredder residue with a microwave pyrolysis combined with high temperature steam gasification  

International Nuclear Information System (INIS)

Presently, there is a growing need for handling automobile shredder residues - ASR or 'car fluff'. One of the most promising methods of treatment ASR is pyrolysis. Apart of obvious benefits of pyrolysis: energy and metals recovery, there is serious concern about the residues generated from that process needing to be recycled. Unfortunately, not much work has been reported providing a solution for treatment the wastes after pyrolysis. This work proposes a new system based on a two-staged process. The ASR was primarily treated by microwave pyrolysis and later the liquid and solid products become the feedstock for the high temperature gasification process. The system development is supported within experimental results conducted in a lab-scale, batch-type reactor at the Royal Institute of Technology (KTH). The heating rate, mass loss, gas composition, LHV and gas yield of producer gas vs. residence time are reported for the steam temperature of 1173 K. The sample input was 10 g and the steam flow rate was 0.65 kg/h. The conversion reached 99% for liquids and 45-55% for solids, dependently from the fraction. The H2:CO mol/mol ratio varied from 1.72 solids and 1.4 for liquid, respectively. The average LHV of generated gas was 15.8 MJ/N m3 for liquids and 15 MJ/N m3 for solids fuels.

38

Recycling of automobile shredder residue with a microwave pyrolysis combined with high temperature steam gasification.  

Science.gov (United States)

Presently, there is a growing need for handling automobile shredder residues--ASR or "car fluff". One of the most promising methods of treatment ASR is pyrolysis. Apart of obvious benefits of pyrolysis: energy and metals recovery, there is serious concern about the residues generated from that process needing to be recycled. Unfortunately, not much work has been reported providing a solution for treatment the wastes after pyrolysis. This work proposes a new system based on a two-staged process. The ASR was primarily treated by microwave pyrolysis and later the liquid and solid products become the feedstock for the high temperature gasification process. The system development is supported within experimental results conducted in a lab-scale, batch-type reactor at the Royal Institute of Technology (KTH). The heating rate, mass loss, gas composition, LHV and gas yield of producer gas vs. residence time are reported for the steam temperature of 1173 K. The sample input was 10 g and the steam flow rate was 0.65 kg/h. The conversion reached 99% for liquids and 45-55% for solids, dependently from the fraction. The H(2):CO mol/mol ratio varied from 1.72 solids and 1.4 for liquid, respectively. The average LHV of generated gas was 15.8 MJ/Nm(3) for liquids and 15 MJ/Nm(3) for solids fuels. PMID:20580160

Donaj, Pawel; Yang, Weihong; B?asiak, W?odzimierz; Forsgren, Christer

2010-10-15

39

Recycling of automobile shredder residue with a microwave pyrolysis combined with high temperature steam gasification  

Energy Technology Data Exchange (ETDEWEB)

Presently, there is a growing need for handling automobile shredder residues - ASR or 'car fluff'. One of the most promising methods of treatment ASR is pyrolysis. Apart of obvious benefits of pyrolysis: energy and metals recovery, there is serious concern about the residues generated from that process needing to be recycled. Unfortunately, not much work has been reported providing a solution for treatment the wastes after pyrolysis. This work proposes a new system based on a two-staged process. The ASR was primarily treated by microwave pyrolysis and later the liquid and solid products become the feedstock for the high temperature gasification process. The system development is supported within experimental results conducted in a lab-scale, batch-type reactor at the Royal Institute of Technology (KTH). The heating rate, mass loss, gas composition, LHV and gas yield of producer gas vs. residence time are reported for the steam temperature of 1173 K. The sample input was 10 g and the steam flow rate was 0.65 kg/h. The conversion reached 99% for liquids and 45-55% for solids, dependently from the fraction. The H{sub 2}:CO mol/mol ratio varied from 1.72 solids and 1.4 for liquid, respectively. The average LHV of generated gas was 15.8 MJ/N m{sup 3} for liquids and 15 MJ/N m{sup 3} for solids fuels.

Donaj, Pawel, E-mail: pawel@mse.kth.se [Division of Energy and Furnace Technology, Royal Institute of Technology, Brinellvagen 23, SE-100 44 Stockholm (Sweden); Yang, Weihong; Blasiak, Wlodzimierz [Division of Energy and Furnace Technology, Royal Institute of Technology, Brinellvagen 23, SE-100 44 Stockholm (Sweden); Forsgren, Christer [Stena Metall AB, Gothenburg (Sweden)

2010-10-15

40

PYROLYSIS OF EMPTY FRUIT BUNCHES: INFLUENCE OF TEMPERATURE ON THE YIELDS AND COMPOSITION OF GASEOUS PRODUCT  

Directory of Open Access Journals (Sweden)

Full Text Available With the increasing concern on fossil fuel depletion and environmental problems, the utilization of renewable biomass resources is expected to play an important role in the future. Biomass can be converted into a variety of fuels and chemicals by different processes; one of which is pyrolysis that has been subjected to extensive research in recent years. In this study, pyrolysis of oil palm Empty Fruit Bunches (EFB was investigated using a quartz fluidised-fixed bed reactor. The effects of pyrolysis temperatures on the yields and composition of gaseous products were investigated. The temperatures of pyrolysis used were in the range of 300-600C. The gaseous products from pyrolysis of (EFB were analyzed using a dual-channel micro-GC with Thermal Conductivity Detector (TCD. The highest and lowest gas yields obtained were 42.98 and 31.55% at 600 and 300C, respectively. The gases detected were Carbon Monoxide (CO, carbon dioxide (CO2, Methane (CH4, Ethane (C2H6 and Ethylene (C2H4. At 300 and 400C, the gas mixture comprised mainly CO2 (20% and CO (20%. Other gases such as CH4, C2H4 and C2H6 only evolved at higher temperature starting from 400C with the yield of the latter two gases in very low concentration.

Mohamad Azri Sukiran

2014-01-01

41

Evaluating the effects of temperature on pressurized pyrolysis of Nannochloropsis oculata based on products yields and characteristics  

International Nuclear Information System (INIS)

Highlights: N. oculata is a suitable feedstock for pyrolysis due to high volatile matter. Temperature effects on product yields and properties during pressurized pyrolysis. Algal bio-oil has high energy content and has similar composition as diesel fuel. Suitability of char as a fuel was based on Van Krevelen diagram. Gas from pyrolysis of N. oculata has high percentage of combustible hydrocarbons. - Abstract: Biofuels derived from pyrolysis of microalgae can be potential alternatives for petroleum-derived fuels. Pyrolysis is an easily controllable thermochemical conversion process that yields energy fuels such as bio-oil, char and combustible gases. Microalgae is a very promising feedstock for this process since it has high lipid content, grows faster than lignocellulosic biomass, has high productivity and high photosynthetic efficiency. Several reaction parameters including temperature could affect the yield and quality of biofuels from pyrolysis. This paper aimed to evaluate the effect of temperature during pyrolysis of Nannochloropsis oculata using a pressurized fixed-bed batch-type reactor. Based on the results, the distribution of the products significantly varied with pyrolysis temperature, and the pyrolysis process can be manipulated to favor one of its products. Bio-oil with high heating value (HHV) of about 38 MJ/kg, due to its high carbon (76wt%) and hydrogen (11wt%) contents, and low oxygen content (7wt%), can be produced from N. oculata. It also consists mainly of saturated (34.95%) and unsaturated aliphatics (34.43%), and aromatics (14.19%) ranging from C8 to C21, which is comparable to diesel fuel. The HHV of the char (27 MJ/kg) and gas (27 MJ/m3) were also relatively high. Based on their heating values (HHV) and compositions, the char, bio-oil and gas produced from pyrolysis of N. oculata can be potentially used as alternative sources of energy. Mass and energy conversion efficiencies of the process were also estimated to be approximately equal to 76% and 68%, respectively

42

Evolution of volatile products from Goynuk (Turkey) oil shales by temperature-programmed pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

It is reported that a fixed-bed reactor was used to pyrolyse small samples of oil shale particles under an inert gas flow (argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperatures and time intervals. The pyrolysis products were analysed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. The maximum volatile product evolution temperature was {approximately} 440{degree}C. The aliphatic hydrocarbon content of the pyrolysis products was characterized and classified by carbon number. In addition, the performance of the experimental system was assessed by a carbon balance. The recovery of total organic carbon as organic volatile products, CO{sub 2} and coke was determined. 9 refs., 7 figs., 2 tabs.

Ballice, L.; Yuksel, M.; Saglam, M.; Schulz, H. [University of Ege, Izmir (Turkey). Dept. of Chemical Engineering

1997-04-01

43

Effect of final pyrolysis temperature on the mechanical and thermal properties of carbon foams reinforced by aluminosilicate  

Energy Technology Data Exchange (ETDEWEB)

Carbon foams with phenolic resin as precursor and aluminosilicate as reinforcement were prepared at different final pyrolysis temperatures. The microstructures, mechanical and thermal properties of the foams were investigated by scanning electron microscopy, mechanical testing and the laser flash method, respectively. The results show that the cells are mainly open with incomplete cell membranes, and the alumninosilicate particles are located in cell walls. The surface of cell openings becomes rougher as the final pyrolysis temperature increases. The ultimate compressive strength increases from 0.45 to 1.74 MPa when increasing the final pyrolysis temperature from 1100 to 1550 Degree-Sign C. The thermal conductivity ranged from 0.37 to 0.52 W m{sup -1} K{sup -1} at room temperature and decreases with increasing the final pyrolysis temperature. The occurrence of the mullite phase plays a key role in the changes of the mechanical properties and thermal conductivity of the foams.

Wu, Xiaowen, E-mail: xwwu@cugb.edu.cn [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China); Fang, Minghao; Mei, Lefu; Luo, Bingcheng [School of Materials Science and Technology, China University of Geosciences, Beijing 100083 (China)

2012-12-15

44

Tar-free fuel gas production from high temperature pyrolysis of sewage sludge  

International Nuclear Information System (INIS)

Highlights: High temperature pyrolysis of sewage sludge was efficient for producing tar-free fuel gas. Complete tar removal and volatile matter release were at elevated temperature of 1300 C. Sewage sludge was converted to residual solid with high ash content. 72.60% of energy conversion efficiency for gas production in high temperature pyrolysis. Investment and costing for tar cleaning were reduced. - Abstract: Pyrolysis of sewage sludge was studied in a free-fall reactor at 10001400 C. The results showed that the volatile matter in the sludge could be completely released to gaseous product at 1300 C. The high temperature was in favor of H2 and CO in the produced gas. However, the low heating value (LHV) of the gas decreased from 15.68 MJ/N m3 to 9.10 MJ/N m3 with temperature increasing from 1000 C to 1400 C. The obtained residual solid was characterized by high ash content. The energy balance indicated that the most heating value in the sludge was in the gaseous product

45

Pyrolysis characteristics of integrated circuit boards at various particle sizes and temperatures  

International Nuclear Information System (INIS)

A pyrolysis method was employed to recycle the metals and brominated compounds blended into printed circuit boards. This research investigated the effect of particle size and process temperature on the element composition of IC boards and pyrolytic residues, liquid products, and water-soluble ionic species in the exhaust, with the overall goal being to identify the pyrolysis conditions that will have the least impact on the environment. Integrated circuit (IC) boards were crushed into 5-40 mesh (0.71-4.4 mm), and the crushed particles were pyrolyzed at temperatures ranging from 200 to 500 deg. C. The thermal decomposition kinetics were measured by a thermogravimetric (TG) analyzer. The composition of pyrolytic residues was analyzed by Energy Dispersive X-ray Spectrometer (EDS), Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). In addition, the element compositions of liquid products were analyzed by ICP-AES and ICP-MS. Pyrolytic exhaust was collected by a water-absorption system in an ice-bath cooler, and IC analysis showed that the absorbed solution comprised 11 ionic species. Based on the pyrolytic kinetic parameters of TG analysis and pyrolytic residues at various temperatures for 30 min, the effect of particle size was insignificant in this study, and temperature was the key factor for the IC board pyrolysis. Two stages of decomposition were found for IC board pyrolysis under nitrogen atmosor IC board pyrolysis under nitrogen atmosphere. The activation energy was 38-47 kcal/mol for the first-stage reaction and 5.2-9.4 kcal/mol for the second-stage reaction. Metal content was low in the liquid by-product of the IC board pyrolysis process, which is an advantage in that the liquid product could be used as a fuel. Brominate and ammonium were the main water-soluble ionic species of the pyrolytic exhaust. A plan for their safe and effective disposal must be developed if the pyrolytic recycling process is to be applied to IC boards

46

Growth Temperature Effect on Carbon Nano tubes Formation by Spray Pyrolysis Method  

International Nuclear Information System (INIS)

Carbon nano tubes has been produced by using spray pyrolysis method with no carrier gas. Carbon nano tubes were formulated from a mixture a ferrocene and benzene with certain ratio and then the mixture were injected by the sprayer into the furnace. Growth temperature was optimized in the range of 650 until 850 oC to get the high quality of carbon nano tubes. These were characterized by Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX). (author)

47

Temperature dependence of ZnO rods produced by ultrasonic spray pyrolysis method  

International Nuclear Information System (INIS)

Zinc oxide (ZnO) microrods were prepared at different substrate temperatures by ultrasonic spray pyrolysis technique on glass substrates. The X-ray diffraction patterns show that obtained rods are composed of wurtzite-type and mainly grow along the [0 0 2] direction. Scanning electron microscope images show that the diameters of ZnO rods and the distances among the rods increase with increasing substrate temperature. In addition, the optical measurements reveal that transmittance and the band gap energies of films increase with increasing substrate temperature

48

Biomass Pyrolysis: Comments on Some Sources of Confusions in the Definitions of Temperatures and Heating Rates  

Directory of Open Access Journals (Sweden)

Full Text Available Biomass pyrolysis is usually characterized on the basis of temperature and heating rate. Unfortunately, these parameters are badly defined in processing reactors as well as in laboratory devices. From the results of simplified models, the present paper points out the significant mistakes that can be made when assuming that the actual temperature and heating rate of reacting biomass particles are the same as those of the external heating medium. The difficulties in defining these two parameters are underlined in both cases of a heat source temperature supposed to be constant or to increase with time.

Jacques Ld

2010-04-01

49

Low-temperature pyrolysis of CCA-treated wood. Thermogravimetric analysis  

Energy Technology Data Exchange (ETDEWEB)

A thermo-analytical study of untreated and chromated copper arsenate (CCA) treated wood samples is performed in order to obtain a better understanding of the low-temperature pyrolysis of CCA-treated wood waste in an inert atmosphere. The type of wood used in this study is Pinus sylvestris sapwood. The influence of the presence of CCA and the heating rate on the pyrolytic behaviour of wood samples is studied, as well as the release of volatile compounds and metals (Cr, Cu, As) during the pyrolysis process. This paper shows that CCA has a significant influence on the thermal behaviour of wood samples, which is more pronounced the higher the CCA concentration of the sample is. The temperature at the onset of pyrolysis, as well as the temperature where the maximum rate of decomposition occurs, are lowered by the CCA treatment. The final char yield (including the metals) is higher and the rate of weight loss is much more peaked for CCA-treated wood. It could be postulated that the CCA compounds act as promotors of the pyrolysis reactions favouring the formation of char. For higher heating rates, there is a shift of the DTG peak to higher temperatures for both untreated and CCA-treated wood samples. Within the accuracy of the evolved gas analysis (EGA) method applied, it is observed that the presence of CCA does not significantly influence the type and relative amount of measured volatiles. The volatilisation of metal compounds is shown to be strongly dependent on temperature and residence time of the wood sample at a given temperature. A critical point (10 min at 400C) exists, below which the release of Cr and Cu is negligible and the release of As is below 10%. Above this critical point (longer times at 400C), there is a dramatic increase in metal release for all three metals. The CCA concentration itself also has an influence in the sense that higher concentrations in the original sample give higher relative concentrations of metals in the resulting pyrolysis residue

Helsen, L.; Van den Bulck, E. [Department of Mechanical Engineering, Katholieke Universiteit Leuven, Celestijnenlann 300A, 3001 Heverlee (Belgium); Mullens, S.; Mullens, J. [Laboratory of Inorganic and Physical Chemistry, Limburgs Universitair Centrum, Gebouw D, 3590 Diepenbeek (Belgium)

1999-09-01

50

Screening acidic zeolites for catalytic fast pyrolysis of biomass and its components  

Science.gov (United States)

Zeolites have been shown to effectively promote cracking reactions during pyrolysis resulting in highly deoxygenated and hydrocarbon-rich compounds and stable pyrolysis oil product. Py/GC-MS was employed to study the catalytic fast pyrolysis of lignocellulosic biomass samples comprising oak, corn...

51

Fuel and fuel blending components from biomass derived pyrolysis oil  

Science.gov (United States)

A process for the conversion of biomass derived pyrolysis oil to liquid fuel components is presented. The process includes the production of diesel, aviation, and naphtha boiling point range fuels or fuel blending components by two-stage deoxygenation of the pyrolysis oil and separation of the products.

McCall, Michael J.; Brandvold, Timothy A.; Elliott, Douglas C.

2012-12-11

52

Microstructure development of chars derived from high-temperature pyrolysis of barley (Hordeum vulgare L.) hulls  

Energy Technology Data Exchange (ETDEWEB)

Fast pyrolysis of biomass is a thermochemical conversion process that provides an economic production of pyrolysis oils/bio-oils. The process also results in a residual solid residue, char, that comprises carbon and mineral ash that can be a potential source of fuel or a valuable co-product. Depending on the exposure time and temperature, pyrolysis can increase the interfacial surface areas of the residual char thereby enhancing its absorptive capacity. Char residues can be used for physical or chemical absorption and as catalyst support or base material for fertilizers. The reactions that occur during char combustion or gasification are heterogeneous hence the reaction rates are microstructure dependent. Ashes from biomass derived chars can be high either in calcium or silica with the latter exceeding 90% levels in certain grain hull residues. Depending on the microstructural transformations which occur during thermal degradation of the biomass, silica-laden ashes can be a potential source of pozzolan for the construction industry. In this study, the microstructure of the chars derived from fast pyrolysis of barley-hull was studied using environmental scanning electron microscopy under low vacuum conditions. The results indicate a gradual increase in convoluted microstructure related to the superficial organization of epidermal cells, including stomata and trichomes that eventually assume the form of various morphotypes of phytoliths. Characterization of the temporal events of high temperature evolution of the hull microstructure provides practical implications of its combustion reactivities and also provides information useful for predicting potential masonry applications for the resulting ash. 18 refs., 8 figs., 3 tabs.

A.A. Boateng; P.H. Cooke; K.B. Hicks [US Department of Agriculture, Wyndmoor, PA (United States). Agriculture Research Service, Eastern Regional Research Center

2007-03-15

53

Hydrogen production from biomass pyrolysis gas via high temperature steam reforming process  

International Nuclear Information System (INIS)

Full text: The aim of this work has been undertaken as part of the design of continuous hydrogen production using the high temperature steam reforming process. The steady-state test condition was carried out using syngas from biomass pyrolysis, whilst operating at high temperatures between 600 and 1200 degree Celsius. The main reformer operating parameters (e.g. temperature, resident time and steam to biomass ratio (S/B)) have been examined in order to optimize the performance of the reformer. The operating temperature is a key factor in determining the extent to which hydrogen production is increased at higher temperatures (900 -1200 degree Celsius) whilst maintaining the same as resident time and S/B ratio. The effects of exhaust gas composition on heating value were also investigated. The steam reforming process produced methane (CH4) and ethylene (C2H4) between 600 to 800 degree Celsius and enhanced production ethane (C2H6) at 700 degree Celsius. However carbon monoxide (CO) emission was slightly increased for higher temperatures all conditions. The results show that the use of biomass pyrolysis gas can produce higher hydrogen production from high temperature steam reforming. In addition the increasing reformer efficiency needs to be optimized for different operating conditions. (author)

54

Pyrolysis temperature induced changes in characteristics and chemical composition of biochar produced from conocarpus wastes.  

Science.gov (United States)

Conocarpus wastes were pyrolyzed at different temperatures (200800 C) to investigate their impact on characteristics and chemical composition of biochars. As pyrolysis temperature increased, ash content, pH, electrical conductivity, basic functional groups, carbon stability, and total content of C, N, P, K, Ca, and Mg increased while biochar yield, total content of O, H and S, unstable form of organic C and acidic functional groups decreased. The ratios of O/C, H/C, (O + N)/C, and (O + N + S)/C tended to decrease with temperature. The data of Fourier transformation infrared indicate an increase in aromaticity and a decrease in polarity of biochar produced at a high temperature. With pyrolysis temperature, cellulose loss and crystalline mineral components increased, as indicated by X-ray diffraction analysis and scanning electron microscope images. Results suggest that biochar pyrolized at high temperature may possess a higher carbon sequestration potential when applied to the soil compared to that obtained at low temperature. PMID:23376202

Al-Wabel, Mohammad I; Al-Omran, Abdulrasoul; El-Naggar, Ahmed H; Nadeem, Mahmoud; Usman, Adel R A

2013-03-01

55

Composition of liquid products from rapid pyrolysis of Datong coal at different temperature  

Energy Technology Data Exchange (ETDEWEB)

The composition of liquid products from rapid pyrolysis of Datong bituminous coal was examined by on-line GC-MS analysis. The characteristics of liquid products derived from low temperature as well as high temperature pyrolysis were comparatively evaluated. The effects of temperature, ranging from 530[degree]C to 950[degree]C, on main liquid compositions were investigated. Above 600[degree]C, the yield of long chain aliphatic hydrocarbon (mostly C[sub 7] to C[sub 22]n-alkane) decreased due to further cracking of aliphatic chains. Benzene yield increased with increasing temperature and this trend was more pronounced when the temperature was above 700[degree]C. Maximum production of toluene, xylene or trimethylbenzene occurred around 800[degree]C. While xylene and trimethylbenzene disappeared at above 950[degree] relatively small amount of toluene remained. Styrene yield slightly changed above 800[degree]C. The yields of phenol, cresol and methyldihydroxybenzene increased proportionally with temperature when it was below 800[degree]C. Xylenol yield began to decrease at 700[degree]C. Cresol, xylenol and creosorcinol were absent at 950[degree]C. The effects of temperature on the yields of naphthalene and methylnaphthalene were similar to those on benzene and methylbenzene respectively. Dimethylnaphthalene and trimethylnaphthalene achieved maximal yield at approximately 600[degree]C and 800[degree]C respectively. 12 refs., 2 figs., 3 tabs.

Wang, J.; Wang, F.; Yan, Y.; Wei, Y.

1993-12-01

56

Solvent-extractable polycyclic aromatic hydrocarbons in biochar: influence of pyrolysis temperature and feedstock.  

Science.gov (United States)

Despite the increasing agricultural use of biochar as a way of combining the utilization of biomass for energy production with the removal of CO(2) from the atmosphere, it is not known how variations in pyrolysis temperature and feedstock type affect concentration and composition of polycyclic aromatic hydrocarbons (PAHs) that inevitably form and associate with biochar. To close this knowledge gap, we quantified 11 unsubstituted three- to five-ring PAHs as well as alkylated forms of phenanthrene and anthracene in grass and wood chars produced in 100 C increments across a temperature range (100 to 700 C). Our results show that solvent-extractable PAH concentrations in biochars produced at heat treatment temperatures (HTTs) of 400 and 500 C greatly exceed those observed at higher and lower temperature, supporting a low HTT solid-phase formation mechanism operable at temperatures commonly used for industrial biochar production. The maximum extractable yield of 'pyrolytic' unsubstituted PAHs for grass (22 ?g g(-1) at HTT = 500 C) greatly exceeds the value for wood (5.9 ?g g(-1)). Moreover, PAH signatures (e.g., total monomethylphenanthrene to phenanthrene ratios, MP/P ~2-3) at intermediate temperatures (400 C) resemble those of fossil oils rather than that commonly attributed to pyrolytic products. Further research is needed to characterize the PAH evolution in modern pyrolysis reactors and assess the fate of biochar-bound PAHs in soils and sediments. Various commonly applied PAH ratios and indicator compounds show promise as markers for specific feedstock materials and pyrolysis conditions of biochars in environmental systems. PMID:22844988

Keiluweit, Marco; Kleber, Markus; Sparrow, Margaret A; Simoneit, Bernd R T; Prahl, Fredrick G

2012-09-01

57

Substrate Temperature Effects on Tin Oxide Films Prepared by Spray Pyrolysis  

International Nuclear Information System (INIS)

Indium-doped tin oxide films were prepared by spray pyrolysis technique at different substrate temperatures ranging from 400-525 degree C. texture coefficients for (200) and (112) reflections of tetragonal Sn O2 were calculated. The surface morphology of the prepared films was revealed by using scanning electron microscope. A dendrite structure was observed in the films deposited at substrate temperature = 525 degree C. The obtained sheet resistance results were correlated with those obtained from x-ray diffraction analysis and scanning electron microscope. 3 figs., 1 tab

58

Zinc Oxide Thin-Film Transistors Fabricated at Low Temperature by Chemical Spray Pyrolysis  

Science.gov (United States)

We report the electrical behavior of undoped zinc oxide thin-film transistors (TFTs) fabricated by low-temperature chemical spray pyrolysis. An aerosol system utilizing aerodynamic focusing was used to deposit the ZnO. Polycrystalline films were subsequently formed by annealing at the relatively low temperature of 140C. The saturation mobility of the TFTs was 2 cm2/Vs, which is the highest reported for undoped ZnO TFTs manufactured below 150C. The devices also had an on/off ratio of 104 and a threshold voltage of -3.5 V. These values were found to depend reversibly on measurement conditions.

Jeong, Yesul; Pearson, Christopher; Lee, Yong Uk; Winchester, Lee; Hwang, Jaeeun; Kim, Hongdoo; Do, Lee-Mi; Petty, Michael C.

2014-11-01

59

Room temperature ferromagnetism in Co doped ZnO thin film grown using spray pyrolysis  

Science.gov (United States)

Co doped ZnO thin films were prepared using spray pyrolysis. XRD results confirm the absence of metallic Co clusters or any other phase different from wurtzite-type ZnO. UV-VIS studies show that the band edge of ZnO films is red-shifted with Co doping. Room temperature ferromagnetism has been observed in ZnCoO films. The field dependence of magnetization (M-H) curve measured at room temperature using SQUID magnetometer exhibits the clear ferromagnetism (FM).

Thakur, Vikas; Verma, Urvashi; Verma, U. P.; Rajaram, P.

2013-06-01

60

Influence of pyrolysis temperature on characteristics and heavy metal adsorptive performance of biochar derived from municipal sewage sludge.  

Science.gov (United States)

To investigate systematically the influence of pyrolysis temperature on properties and heavy metal adsorption potential of municipal sludge biochar, biophysical dried sludge was pyrolyzed under temperature varying from 500C to 900C. The biochar yield decreased with the increase in pyrolysis temperature, while the ash content retained mostly, thus transforming the biochars into alkaline. The structure became porous as the temperature increased, and the concentrations of surface functional group elements remained low. Despite the comparatively high content of heavy metal in the biochar, the leaching toxicity of biochars was no more than 20% of the Chinese standard. In the batch experiments of cadmium(II) adsorption, the removal capacity of biochars improved under higher temperature, especially at 800C and 900C even one order of magnitude higher than that of the commercial activated carbon. For both energy recovery and heavy metal removal, the optimal pyrolysis temperature is 900C. PMID:24835918

Chen, Tan; Zhang, Yaxin; Wang, Hongtao; Lu, Wenjing; Zhou, Zeyu; Zhang, Yuancheng; Ren, Lulu

2014-07-01

61

Influence of fast pyrolysis temperature on biochar labile fraction and short-term carbon loss in a loamy soil  

International Nuclear Information System (INIS)

Production of bio-oil, gas and biochar from pyrolysis of biomass is considered a promising technology for combined production of bioenergy and recalcitrant carbon (C) suitable for sequestration in soil. Using a fast pyrolysis centrifuge reactor (PCR) the present study investigated the relation between fast pyrolysis of wheat straw at different reactor temperatures and the short-term degradability of biochar in soil. After 115 days incubation 3-12% of the added biochar-C had been emitted as CO2. On average, 90% of the total biochar-C loss occurred within the first 20 days of the experiment, emphasizing the importance of knowing the biochar labile fraction when evaluating a specific biochars C sequestration potential. The pyrolysis temperature influenced the outputs of biochar, bio-oil and syngas significantly, as well as the stability of the biochar produced. Contrary to slow pyrolysis a fast pyrolysis process may result in incomplete conversion of biomass due to limitations to heat transfer and kinetics. In our case chemical analysis of the biochars revealed unconverted cellulosic and hemicellulosic fractions, which in turn were found to be proportional with the short-term biochar degradation in soil. As these labile carbohydrates are rapidly mineralized, their presence lowers the biochar-C sequestration potential. By raising the pyrolysis temperature, biochar with none or low contents of these fractions can be produced, but this will be on the expense of the biochar quantity. The yield of CO2 neutral bio-oil is the other factor to optimize when adjusting the pyrolysis temperature settings to give the overall greatest climate change mitigation effect.

62

Influence of fast pyrolysis temperature on biochar labile fraction and short-term carbon loss in a loamy soil  

DEFF Research Database (Denmark)

Production of bio-oil, gas and biochar from pyrolysis of biomass is considered a promising technology for combined production of bioenergy and recalcitrant carbon (C) suitable for sequestration in soil. Using a fast pyrolysis centrifuge reactor (PCR) the present study investigated the relation between fast pyrolysis of wheat straw at different reactor temperatures and the short-term degradability of biochar in soil. After 115 days incubation 312% of the added biochar-C had been emitted as CO2. On average, 90% of the total biochar-C loss occurred within the first 20 days of the experiment, emphasizing the importance of knowing the biochar labile fraction when evaluating a specific biochars C sequestration potential. The pyrolysis temperature influenced the outputs of biochar, bio-oil and syngas significantly, as well as the stability of the biochar produced. Contrary to slow pyrolysis a fast pyrolysis process may result in incomplete conversion of biomass due to limitations to heat transfer and kinetics. In our case chemical analysis of the biochars revealed unconverted cellulosic and hemicellulosic fractions, which in turn were found to be proportional with the short-term biochar degradation in soil. As these labile carbohydrates are rapidly mineralized, their presence lowers the biochar-C sequestration potential. By raising the pyrolysis temperature, biochar with none or low contents of these fractions can be produced, but this will be on the expense of the biochar quantity. The yield of CO2 neutral bio-oil is the other factor to optimize when adjusting the pyrolysis temperature settings to give the overall greatest climate change mitigation effect.

Bruun, Esben; Hauggaard-Nielsen, Henrik

2011-01-01

63

Carbon crystallization during high-temperature pyrolysis of coals and the enhancement by calcium  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of five coals has been carried out at 1000-1350{sup o}C and different heating rates with fixed-bed and free-fall reactors to examine carbon structures in devolatilized chars. The X-ray diffraction measurements show the formation of crystallized carbon with turbostratic structures, depending strongly on coal type and severity of pyrolysis. The proportion of the carbon with low rank coals decreases by demineralization with acid washing but contrarily increases by subsequent addition of Ca{sup 2+} ions, irrespective of heating rate, and a small amount of 0.5-1 wt % Ca works efficiently. It is thus likely that Ca{sup 2+} ions naturally present as ion-exchanged forms in low rank coals determine dominantly the extent of carbon crystallization at higher temperatures. The Ca added is transformed to fine particles of CaO upon pyrolysis, and a larger amount of CO is formed in the presence of the Ca. A mechanism for the Ca-enhanced carbon crystallization is discussed in terms of solid-solid interactions between CaO particles and amorphous carbon. 23 refs., 9 figs., 1 tab.

Naoto Tsubouchi; Chunbao Xu; Yasuo Ohtsuka [Tohoku University, Sendai (Japan). Research Center for Sustainable Materials Engineering, Institute of Multidisciplinary Research for Advanced Materials

2003-10-01

64

Influence of Pyrolysis Temperature and Heating Rate in the Fabrication of Carbon Membrane: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Despite its brittleness and relatively high fabrication cost, the excellent performance of carbon membrane in gas separation outweighs such limitations. The carbon-based membranes have the capability to perform specific gas separations when compared to other types of membranes or any conventional separation technology that based on cryogenic, adsorption or absorption mechanisms. Basically, carbon membrane is a derivation of its polymeric precursor membrane. The derivation refers to the pyrolysis process of the polymeric membrane that turns it into a carbon membrane. During the process, the polymeric membrane undergoes a controlled thermal treatment and at the same time, inert atmosphere is continuously generated to remove any oxidizing agents. This process is proven to be highly critical and challenging because it determines the final pore structure and its corresponding performances of the carbon membrane. Heating rate and pyrolysis temperature are part of the pyrolysis process and the most tuned parameters to obtain a very fine carbon membrane according to an intended application-based performance. These parameters have been reported numerously for their significant impacts on the fabrication of carbon membranes and this paper provides the review.

M.A.T. Jaya

2014-01-01

65

Epitaxial thick film of YBCO by high temperature spray pyrolysis for coated conductors  

International Nuclear Information System (INIS)

YBCO thick films have been synthesized using a low cost spray pyrolysis method. We used an all nitrate precursor approach to grow epitaxial HTS oxide film on SrTiO3 (0 0 1) substrate at a high deposition rate and at high temperature (over 800 deg. C). In these experiments thick YBCO films (?m) were grown in situ at 850 deg. C within 4 min; the final sintering process is performed at the same temperature for 2 h under oxygen atmosphere before low temperature oxygen loading. X-ray diffraction results (?-2? scans and ? scans) show that the films have not only a strong c-axis texture (mis-orientation ?0.4 deg.) but also a sharp in-plane biaxial orientation (mis-orientation is ?1.4 deg.). The critical temperature (Tc) was 91 K and the critical current density (Jc) higher than 1.4x106 A/cm2 (at 77 K, 0 T), while film thickness is over 1 ?m. Spray pyrolysis is a promising technique for coated conductors

66

Formation of PAH and soot during acetylene pyrolysis at different gas residence times and reaction temperatures  

International Nuclear Information System (INIS)

The formation of polycyclic aromatic hydrocarbons (PAH) and soot from the pyrolysis of acetylene was studied, taking into account the influence of the operating conditions, such as gas residence time and temperature. The influence of gas residence time was considered between 1.28 and 3.88 s for the experiments carried out under different temperatures from 1073 to 1223 K. The total PAH was calculated as the addition of PAH concentration found in different locations, namely adsorbed on soot and on the reactor walls, and at the outlet gas stream. The relationship between the PAH concentrations and their carcinogenic equivalence sum (KE) was also evaluated. The results obtained showed that temperature and residence time have a high influence on pyrolysis products, especially on the PAH concentration adsorbed on soot, which exhibited the highest KE in all cases studied. -- Highlights: ? This study analyses the influence of gas residence time and reaction temperature on PAH and soot formation. ? The present work develops an analytical method for PAH-priorities quantification. ? A major amount of PAH adsorbed on soot is found under every evaluated condition. ? High PAH concentration does not necessarily involve more dangerous effects.

67

Nitrogen enrichment potential of biochar in relation to pyrolysis temperature and feedstock quality.  

Science.gov (United States)

Nitrogen (N) enrichment of biochar from both inorganic and organic waste N sources has the potential to add economic and environmental value through its use as a slow release N fertilizer. We investigated the sorption of N by, and its release from, biochar made at pyrolysis temperatures of 400, 500 and 600C from three feedstocks: poultry litter (PL with a carbon (C) to N ratio (C:N) of 14), softwood chips of spruce-pine-fir (SPF with a C:N of 470), and a 50:50 mixture of PL and SPF (PL/SPF). The prepared biochars were enriched with ammonium nitrate (AN) and urea ammonium nitrate (UAN). PL biochars had the lowest C content (50-56% C), but the highest pH (9.3-9.9), electrical conductivity (EC, 780-960dSm(-1)), cation exchange capacity (CEC, 40-46cmolkg(-1)), and N content (3.3-4.5%). While N content and hydrogen (H) to C atomic ratio (H:C) decreased with increasing pyrolysis temperature irrespective of the feedstock used, both pH and EC slightly increased with pyrolysis temperature for all feedstocks. The PL and SPF biochars showed similar H:C and also similar N sorption and N release at all pyrolysis temperatures. These biochars sorbed up to 5% N by mass, irrespective of the source of N. However, PL/SPF biochar performed poorly in sorbing N from either AN or UAN. Biochar H:C was found to be unrelated to N sorption rates, suggesting that physical adsorption on active surfaces was the main mechanism of N sorption in these biochars. There were minor differences between N sorbed from NO3-N and NH4-N among different biochars. Very small amounts of sorbed N (0.2-0.4mgNg(-1) biochar) was released when extracted with 1M KCl solution, indicating that the retained N was strongly held in complex bonds, more so for NH4-N because the release of NO3-N was 3-4 times greater than that of NH4-N. NH4-N sorption far exceeded the effective CEC of the biochars, thereby suggesting that most of the sorption may be due to physical entrapment of NH4(+) in biochar pores. The results of this study suggest that biochar can be used to remove excess N from poultry and dairy manure and be a good mitigation option for reducing N leaching and gaseous losses. PMID:25621388

Jassal, Rachhpal S; Johnson, Mark S; Molodovskaya, Marina; Black, T Andrew; Jollymore, Ashlee; Sveinson, Kelly

2015-04-01

68

Physical properties of ZnO thin films deposited at various substrate temperatures using spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Zinc oxide (ZnO) thin films have been deposited with various substrate temperatures by spray pyrolysis technique onto glass substrates. X-ray diffraction (XRD) results showed the random growth orientation of the crystallites and the presence of the wurtzite phase of ZnO. The x-ray photoelectron spectroscopy (XPS) measurements reveal the presence of Zn{sup 2+} and chemisorbed oxygen in ZnO thin films. Atomic force micrograms (AFM) revealed a granular, polycrystalline morphology for the films. The grain size is found to increase as the substrate temperature increases. All films exhibit a transmittance of about 85% in the visible region. The photoluminescence (PL) measurements indicated that the intensity of emission peaks significantly varying with substrate temperature. Electrical resistivity has been found to decrease; while the carrier concentration increases with substrate temperature.

Prasada Rao, T., E-mail: prasadview@gmail.co [Advanced Materials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli-620015 (India); Santhosh Kumar, M.C., E-mail: santhoshmc@yahoo.co [Advanced Materials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli-620015 (India); Safarulla, A. [Advanced Materials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli-620015 (India); Ganesan, V.; Barman, S.R. [UGC-DAE Consortium for Scientific Research, Indore-452001 (India); Sanjeeviraja, C. [School of Physics, Alagappa University, Karaikudi-630003 (India)

2010-05-01

69

Physical properties of ZnO thin films deposited at various substrate temperatures using spray pyrolysis  

International Nuclear Information System (INIS)

Zinc oxide (ZnO) thin films have been deposited with various substrate temperatures by spray pyrolysis technique onto glass substrates. X-ray diffraction (XRD) results showed the random growth orientation of the crystallites and the presence of the wurtzite phase of ZnO. The x-ray photoelectron spectroscopy (XPS) measurements reveal the presence of Zn2+ and chemisorbed oxygen in ZnO thin films. Atomic force micrograms (AFM) revealed a granular, polycrystalline morphology for the films. The grain size is found to increase as the substrate temperature increases. All films exhibit a transmittance of about 85% in the visible region. The photoluminescence (PL) measurements indicated that the intensity of emission peaks significantly varying with substrate temperature. Electrical resistivity has been found to decrease; while the carrier concentration increases with substrate temperature.

70

Characterization of bio-oil and biochar from high-temperature pyrolysis of sewage sludge.  

Science.gov (United States)

The influence of temperature (550-850C) on the characteristics of bio-oil and biochar from the pyrolysis of sewage sludge (SS) in a horizontal tube reactor was investigated. Results showed that when the pyrolysis temperature increased from 550C to 850C, the yield of bio-oil decreased from 26.16% (dry ash-free basis) to 20.78% (dry ash-free basis). Main components of bio-oil were phenols, esters, cholests, ketones, amides, indoles, and nitriles. Besides, the elevated heating rate of 25C/min was demonstrated to favour the complete combustion of bio-oil. Moreover, caused by the increase in temperature, the yield of biochar decreased from 54.9 to 50.6wt%, Brunauer-Emmet-Teller surface area increased from 48.51 to 81.28?m(2)/g. Furthermore, pH was increased from 5.93 of SS to 7.15-8.96 of biochar. The negative ?-potential was also strengthened (-13.87 to -11.30?mV) and principal functional groups on the surface of biochar were -OH, C=O, C=C, -NO2, and S=O. PMID:25518986

Chen, Hongmei; Zhai, Yunbo; Xu, Bibo; Xiang, Bobin; Zhu, Lu; Qiu, Lei; Liu, Xiaoting; Li, Caiting; Zeng, Guangming

2015-02-01

71

Flame temperature trends in reacting vanadium and tungsten ethoxide fluid sprays during CO2-laser pyrolysis  

Science.gov (United States)

We observe the "invisible-to-the-naked-eye" flames of tungsten and vanadium ethoxide aerosols when ignited at moderate laser excitation (0emission is seen in the visible range whether by the visible region cameras or by spectroscopy. The emissivity of the precursor solution measured was 0.80 and 0.75 for tungsten and vanadium ethoxide, respectively. The spectral emissivities of the tungsten and vanadium ethoxide flames measured using FTIR-spectrometer were used to calculate the pyrolysis flame temperature at various laser intensities and wavelengths. New energy balance equations have been derivedthe transient temperature one extended from Haggerty-Cannon equation and the other based on standard resonance analysis. Fitting these models to experimental data reveals that only small amounts (1.33% and 4.32%, respectively) of the laser power are used in the pyrolysis of the precursor ethoxide aerosols into the desired oxide nanostructures. The low levels of specific heat capacity values obtained in these sprays suggest that these are electronic heat capacities rather than lattice heat capacities; enthalpies are also obtained. The experimental temperature-laser power trends observed were in agreement with previous findings from Tenegal et al. (Chem. Phys. Lett. 335:155, 2001). The damping coefficients, and hence the saturation intensities confirm that the vanadium containing precursor liquid is harder to dissociate into final products than the tungsten precursor as observed experimentally.

Mwakikunga, B. W.; Mudau, A. E.; Brink, N.; Willers, C. J.

2011-11-01

72

Release of fuel-bound nitrogen in biomass during high temperature pyrolysis and gasification  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis and gasification of two biomass feedstocks with significantly different fuel-bound nitrogen (FBN) content were investigated to determine the effect of operating conditions on the partitioning of FBN among gas species. Experiments were performed in a bench-scale, indirectly-heated, fluidized bed reactor. Data were obtained over a range of temperatures and equivalence ratios representative of commercial biomass gasification processes. An assay of all major nitrogenous components of the gasification products was performed for the first time, providing a clear accounting of the evolution of FBN. Results indicate that: (1) NH{sub 3} is the dominant nitrogenous gas species produced during pyrolysis of biomass; (2) the majority of FBN is converted to NH{sub 3} or N{sub 2} during gasification; relative levels of NH{sub 3} and N{sub 2} are determined by thermochemical reactions which are affected strongly by temperature; (3) N{sub 2} appears to be produced from NH{sub 3} in the gas phase.

Zhou, J.; Masutani, S.M.; Ishimura, D.M.; Turn, S.Q.; Kinoshita, C.M. [Univ. of Hawaii, Honolulu, HI (United States)

1997-12-31

73

Formation of brominated pollutants during the pyrolysis and combustion of tetrabromobisphenol A at different temperatures  

International Nuclear Information System (INIS)

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant worldwide. A detailed examination of the degradation products emitted during thermal decomposition of TBBPA is presented in the study. Runs were performed in a laboratory furnace at different temperatures (650 and 800C) and in different atmospheres (nitrogen and air). More than one hundred semivolatile compounds have been identified by GC/MS, with special interest in brominated ones. Presence of HBr and brominated light hydrocarbons increased with temperature and in the presence of oxygen. Maximum formation of PAHs is observed at pyrolytic condition at the higher temperature. High levels of 2,4-, 2,6- and 2,4,6- bromophenols were found. The levels of polybrominated dibenzo-p-dioxins and furans have been detected in the ppm range. The most abundant isomers are 2,4,6,8-TeBDF in pyrolysis and 1,2,3,7,8-PeBDF in combustion. These results should be considered in the assessment of thermal treatment of materials containing brominated flame retardants. - Highlights: Decomposition of a brominated flame retardant is performed in a laboratory furnace. Both pyrolysis and combustion at two different temperatures are studied. Brominated organic compounds such as Br-dioxins and furans are analysed. Main product of decomposition is HBr, accounting for ca. 50%. Very high and dangerous levels of PBDD/Fs and precursors (bromophenols) are detected. - TBBPA mainly decomposes to give HBr and brominated hydrocarbons at high temperature, but high levels of bromophenols and polybrominated dibenzo-p-dioxins and furans are also produced

74

Pyrolysis behaviors of wood and its constituent polymers at gasification temperature  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis behavior of wood at gasification temperature (800 C) was investigated focusing on the behaviors of the wood constituent polymers [cellulose, hemicellulose (glucomannan and xylan) and lignin (milled wood lignin)]. Tar compositions (iso-propanol-soluble and water-soluble tar fractions), which were characterized with GPC, GC-MS, GC-FID (oxime-TMS analysis), capillary electrophoresis and {sup 1}H NMR analysis, were quite different between wood polysaccharides and lignin. Furthermore, comparison of the tar- and secondary char-forming behaviors indicated that comparatively stable primary tar from wood polysaccharides undergo secondary reactions including carbonization after condensation at the reactor wall with lower temperature than their boiling points, while that primary tar from lignin is more reactive to give the vapor phase carbonization products during volatilization. (author)

Hosoya, T.; Kawamoto, H.; Saka, S. [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan)

2007-03-15

75

RELATION BETWEEN MECHANICAL PROPERTIES AND PYROLYSIS TEMPERATURE OF PHENOL FORMALDEHYDE RESIN FOR GAS SEPARATION MEMBRANES  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000C, together with closure of mesopores and macropores. Samples cured and pyrolyzed at 1000C pronounced hysteresis of desorption branch. The ultimate bending strength was measured using a four-point arrangement that is more suitable for measuring of brittle materials. The chevron notch technique was used for determination the fracture toughness. The results for mechanical properties indicated that phenol-formaldehyde resin pyrolyzates behaved similarly to ceramic materials. The data obtained for the material can be used for calculating the technical design of gas separation membranes.

MONIKA UPOV

2012-03-01

76

Classification of volatile products evolved during temperature-programmed co-pyrolysis of Turkish oil shales with low density polyethylene  

Energy Technology Data Exchange (ETDEWEB)

Temperature programmed co-pyrolysis of Turkish oil shales with LDPE was investigated. The aim of this research was determine the volatile product distribution and product evolution rate of coprocessing of oil shale with LDPE. A series co-pyrolysis operation was performed with oil shale and LDPE using a 1:3, 1:1, 3:1 total carbon ratio of oil shale to plastic. A fixed bed reactor was used to pyrolyse small sample of oil shale and LDPE mixture under an inert gas flow (Argon). A special sampling technique was used for collecting organic products eluted from the reactor at different temperature and time intervals. The co-pyrolysis products were analysed by capillary gas chromatography and the total product evolution rate was investigated as a function of temperature and time. n-Paraffins and 1-olefins in aliphatic fraction of pyrolysis products was determined. The assessments were based on incorporating the results on temperature-programmed pyrolysis of oil shale and LDPE. The effect of coprocessing of oil shale with LDPE was determined by calculating the difference between the experimental and the hypothetical mean value of conversion of total organic carbon into volatile products. The effect of kerogen type of oil shale on co-pyrolysis operation was also investigated. Conversion into volatile hydrocarbons was found to be lower with increasing LDPE ratio in oil shale-LDPE system while C{sub 16+} hydrocarbons and the amount of coke deposit were higher in the presence of LDPE. 10 refs., 8 figs., 10 tabs.

Ballice, L.; Yuksel, M.; Saglam, M.; Reimert, R.; Schulz, H. [University of Ege, Izmir (Turkey). Dept. of Chemical Engineering

1998-10-01

77

Formation of hydrogen chloride during temperature-programmed pyrolysis of coals with different ranks  

Energy Technology Data Exchange (ETDEWEB)

The evolution of HCl during pyrolysis of 16 coals with different ranks at a heating rate of 10 C/min has been studied with an online monitoring method. Approximately 50%-95% of total chlorine is converted to HCl up to 800{sup o}C, and the remainder is mostly retained in the char, which leads to a strong reverse correlation between the two. As the sum of Na and Ca naturally present in coal increases, the amount of HCl tends to decrease. The temperature dependence of the rate of HCl evolved differs with each coal and shows at least four peaks at 280, 360, 480, and 580{sup o}C. The former two peaks are present for two coals alone, whereas the higher temperature HCl formation at {>=}450{sup o}C is common for almost all of the coals. The HCl peaks at 280 and 360{sup o}C are considerably small by water washing. When model chlorine compounds added to activated carbon, such as hydrated NaCl, hydrated CaCl{sub 2}, and organic hydrochlorides, are pyrolyzed in the same manner as above, HCl formation occurs dominantly between 250 and 450{sup o}C in every case. The pretreatment of a brown coal char with HCl at 500{sup o}C and subsequent temperature-programmed desorption (TPD) measurement up to 950{sup o}C suggest that HCl reacts with the nascent char upon pretreatment to form several types of Cl functional forms, from which the HCl desorption takes place at 450-750{sup o}C upon TPD. The HCl evolved at {lt}450{sup o}C during pyrolysis may arise from water-soluble Cl functional groups in coal, whereas the HCl formation at 450{sup o}C observed for almost all of the coals may proceed through a mechanism involving secondary reactions of HCl evolved at a lower temperature. 18 refs., 9 figs., 3 tabs.

Naoto Tsubouchi; Shinya Ohtsuka; Yoshihiro Nakazato; Yasuo Ohtsuka [Tohoku University, Sendai (Japan). Research Center for Sustainable Materials Engineering, Institute of Multidisciplinary Research for Advanced Materials

2005-04-01

78

Low temperature pyrolysis of coal or oil shale in the presence of calcium compounds  

Science.gov (United States)

A coal pyrolysis technique or process is described in which particulate coal is pyrolyzed in the presence of about 5 to 21 wt. % of a calcium compound selected from calcium oxide, calcined (hydrate) dolomite, or calcined calcium hydrate to produce a high quality hydrocarbon liquid and a combustible product gas which are characterized by low sulfur content. The pyrolysis is achieved by heating the coal-calcium compound mixture at a relatively slow rate at a temperature of about 450.degree. to 700.degree. C. over a duration of about 10 to 60 minutes in a fixed or moving bed reactor. The gas exhibits an increased yield in hydrogen and C.sub.1 -C.sub.8 hydrocarbons and a reduction in H.sub.2 S over gas obtainable by pyrolyzing cola without the calcium compound. The liquid product obtained is of a sufficient quality to permit its use directly as a fuel and has a reduced sulfur and oxygen content which inhibits polymerization during storage.

Khan, M. Rashid (Morgantown, WV)

1988-01-01

79

Indium oxide thin-film transistors processed at low temperature via ultrasonic spray pyrolysis.  

Science.gov (United States)

The use of ultrasonic spray pyrolysis is demonstrated for the growth of polycrystalline, highly uniform indium oxide films at temperatures in the range of 200-300 C in air using an aqueous In(NO3)3 precursor solution. Electrical characterization of as-deposited films by field-effect measurements reveals a strong dependence of the electron mobility on deposition temperature. Transistors fabricated at ?250 C exhibit optimum performance with maximum electron mobility values in the range of 15-20 cm(2) V (-1) s(-1) and current on/off ratio in excess of 10(6). Structural and compositional analysis of as-grown films by means of X-ray diffraction, diffuse scattering, and X-ray photoelectron spectroscopy reveal that layers deposited at 250 C are denser and contain a reduced amount of hydroxyl groups as compared to films grown at either lower or higher temperatures. Microstructural analysis of semiconducting films deposited at 250 C by high resolution cross-sectional transmission electron microscopy reveals that as-grown layers are extremely thin (?7 nm) and composed of laterally large (30-60 nm) highly crystalline In2O3 domains. These unique characteristics of the In2O3 films are believed to be responsible for the high electron mobilities obtained from transistors fabricated at 250 C. Our work demonstrates the ability to grow high quality low-dimensional In2O3 films and devices via ultrasonic spray pyrolysis over large area substrates while at the same time it provides guidelines for further material and device improvements. PMID:25490965

Faber, Hendrik; Lin, Yen-Hung; Thomas, Stuart R; Zhao, Kui; Pliatsikas, Nikos; McLachlan, Martyn A; Amassian, Aram; Patsalas, Panos A; Anthopoulos, Thomas D

2015-01-14

80

Influence of pyrolysis temperature on biochar property and function as a heavy metal sorbent in soil.  

Science.gov (United States)

While a large-scale soil amendment of biochars continues to receive interest for enhancing crop yields and to remediate contaminated sites, systematic study is lacking in how biochar properties translate into purported functions such as heavy metal sequestration. In this study, cottonseed hulls were pyrolyzed at five temperatures (200, 350, 500, 650, and 800 C) and characterized for the yield, moisture, ash, volatile matter, and fixed carbon contents, elemental composition (CHNSO), BET surface area, pH, pHpzc, and by ATR-FTIR. The characterization results were compared with the literature values for additional source materials: grass, wood, pine needle, and broiler litter-derived biochars with and without post-treatments. At respective pyrolysis temperatures, cottonseed hull chars had ash content in between grass and wood chars, and significantly lower BET surface area in comparison to other plant source materials considered. The N:C ratio reached a maximum between 300 and 400 C for all biomass sources considered, while the following trend in N:C ratio was maintained at each pyrolysis temperature: wood?cottonseed hull?grass?pine needle?broiler litter. To examine how biochar properties translate into its function as a heavy metal (NiII, CuII, PbII, and CdII) sorbent, a soil amendment study was conducted for acidic sandy loam Norfolk soil previously shown to have low heavy metal retention capacity. The results suggest that the properties attributable to the surface functional groups of biochars (volatile matter and oxygen contents and pHpzc) control the heavy metal sequestration ability in Norfolk soil, and biochar selection for soil amendment must be made case-by-case based on the biochar characteristics, soil property, and the target function. PMID:21348519

Uchimiya, Minori; Wartelle, Lynda H; Klasson, K Thomas; Fortier, Chanel A; Lima, Isabel M

2011-03-23

81

Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas  

International Nuclear Information System (INIS)

Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 ?m): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

82

Temperature and Thickness Effects on Electrical Properties of InP Films Deposited by Spray Pyrolysis  

International Nuclear Information System (INIS)

InP film samples are prepared by spray pyrolysis technique using aqueous solutions of InCl3 and Na2HPO4, which are atomized with compressed air as carrier gas onto glass substrates at 500 C with different thicknesses of the films. The structural properties of the samples are determined by x-ray diffraction (XRD). It is found that the crystal structure of the InP films is polycrystalline hexagonal. The orientations of all the obtained films are along the c-axis perpendicular to the substrate. The electrical measurements of the samples are obtained by dc four-probe technique on rectangular-shape samples. The effects of temperature on the electrical properties of the InP films are studied in detail

83

Low oxygen biomass-derived pyrolysis oils and methods for producing the same  

Energy Technology Data Exchange (ETDEWEB)

Low oxygen biomass-derived pyrolysis oils and methods for producing them from carbonaceous biomass feedstock are provided. The carbonaceous biomass feedstock is pyrolyzed in the presence of a catalyst comprising base metal-based catalysts, noble metal-based catalysts, treated zeolitic catalysts, or combinations thereof to produce pyrolysis gases. During pyrolysis, the catalyst catalyzes a deoxygenation reaction whereby at least a portion of the oxygenated hydrocarbons in the pyrolysis gases are converted into hydrocarbons. The oxygen is removed as carbon oxides and water. A condensable portion (the vapors) of the pyrolysis gases is condensed to low oxygen biomass-derived pyrolysis oil.

Marinangeli, Richard; Brandvold, Timothy A; Kocal, Joseph A

2013-08-27

84

Kinetics of petroleum generation by programmed-temperature closed-versus open-system pyrolysis  

Science.gov (United States)

Bulk petroleum generation by programmed-temperature pyrolysis of immature ( Rr = 0.48%) Posidonia (Toarcian) Shale samples at heating rates of 0.1, 0.7, and 5.0 K/min has been studied comparatively under open- and closed-system conditions, using the microscale sealed vessel (MSSV) technique in the latter case. The comparison of formation rates required a differentiation (vs. temperature) of closed-system cumulative product evolution profiles. The kinetic analysis assuming twenty-five first order parallel reactions with activation energies regularly spaced between 46 and 70 kcal/mol and a single preexponential factory yielded the same value of A = 1.08 10 16 min -1 and very similar petroleum potential vs. activation energy distributions centered around 54 kcal/mol in both cases. In particular, both approaches turned out to be in excellent agreement with respect to predicting temperature ranges of oil and gas formation under geological heating conditions. This is in contrast to the case of petroleum yield assessment which appears to be more system-dependent.

Schenk, H. J.; Horsfield, B.

1993-02-01

85

Effect of temperature during the spray pyrolysis synthesis of silver nanopowder  

International Nuclear Information System (INIS)

We report the results of the synthesis and characterization of Ag, AgO, AgNO3 nanopowders or mixtures of them, obtained by spray pyrolysis technique. An aqueous solution of AgNO3 with a concentration of 0.2 mol/L was sprayed through a horizontal tubular furnace where the solvent was evaporated and pyrolytic reaction occurs producing AgNO3, AgO and Ag particles. The synthesis was made at 500, 600 and 700 oC. The obtained material was analyzed by Transmission Electron Microscopy, and the optimal temperature to obtain particles of around 10 nm was 600 oC. The X-rays and Electron Diffraction analysis determined the coexistence of the phases of Ag, AgO and AgNO3, whereas the measurement of x-rays fluorescence the presence of Ag was detected. The solution concentration and the carrier flow, the temperature and the temperature gradient in the furnace influence in the phase and size of the particle.. (author)

86

Performance of a biological deoxygenation process for ships' ballast water treatment under very cold water conditions.  

Science.gov (United States)

Water deoxygenation is listed among the promising on-board treatment technologies to treat ships' ballast waters to reduce the risk of species transfer. We assessed the performance of a yeast-based bioreactive deoxygenation process in very cold water (waters. Experiments using two treatment levels (0.5% and 1% v/v) were conducted in large-volume (4.5m(3)) tanks over 19 days at mean temperature of 1.5C. Time to hypoxia varied between 10.3 and 16 days, being slightly higher than the predicted time of 9.8 days from previous empirical relationships. Water deoxygenation was achieved when yeast density exceeded 510(5) viable cellsmL(-1) and variation in time to hypoxia was mainly explained by difference in yeast growth. There was no oxycline and no significant difference in yeast density over the 2-m deep water column. Results from six bioassays indicated weak toxic response of treated waters at the 1.0% level, but no potential toxic response at the 0.5% treatment level. Results confirmed that the potential application of a yeast-based deoxygenation process for treating ships' ballast waters extended over the range of water temperature typically encountered during most shipping operational conditions. Time to reach full deoxygenation may however be limiting for universal application of this treatment which should be preferably used for ships making longer voyages in cold environments. There was no evidence that biological deoxygenation at low temperature did increase toxicity risk of treated waters to impede their disposal at the time of discharge. PMID:24345863

de Lafontaine, Yves; Despatie, Simon-Pierre

2014-02-15

87

Short-Term Effect of Feedstock and Pyrolysis Temperature on Biochar Characteristics, Soil and Crop Response in Temperate Soils  

OpenAIRE

At present, there is limited understanding of how biochar application to soil could be beneficial to crop growth in temperate regions and which biochar types are most suitable. Biochars (two feedstocks: willow, pine; three pyrolysis temperatures: 450 C, 550 C, 650 C) effect on nitrogen (N) availability, N use efficiency and crop yield was studied in northwestern European soils using a combined approach of process-based and agronomic experiments. Biochar labile carbon (C) fractions we...

Victoria Nelissen; Greet Ruysschaert; Dorette Mller-Stver; Samuel Bod; Jason Cook; Frederik Ronsse; Simon Shackley; Pascal Boeckx; Henrik Hauggaard-Nielsen

2014-01-01

88

Short-Term Effect of Feedstock and Pyrolysis Temperature on Biochar Characteristics, Soil and Crop Response in Temperate Soils  

Directory of Open Access Journals (Sweden)

Full Text Available At present, there is limited understanding of how biochar application to soil could be beneficial to crop growth in temperate regions and which biochar types are most suitable. Biochars (two feedstocks: willow, pine; three pyrolysis temperatures: 450 C, 550 C, 650 C effect on nitrogen (N availability, N use efficiency and crop yield was studied in northwestern European soils using a combined approach of process-based and agronomic experiments. Biochar labile carbon (C fractions were determined and a phytotoxicity test, sorption experiment, N incubation experiment and two pot trials were conducted. Generally, biochar caused decreased soil NO3? availability and N use efficiency, and reduced biomass yields compared to a control soil. Soil NO3? concentrations were more reduced in the willow compared to the pine biochar treatments and the reduction increased with increasing pyrolysis temperatures, which was also reflected in the biomass yields. Woody biochar types can cause short-term reductions in biomass production due to reduced N availability. This effect is biochar feedstock and pyrolysis temperature dependent. Reduced mineral N availability was not caused by labile biochar C nor electrostatic NH4+/NO3? sorption. Hence, the addition of fresh biochar might in some cases require increased fertilizer N application to avoid short-term crop growth retardation.

Victoria Nelissen

2014-01-01

89

Short-Term Effect of Feedstock and Pyrolysis Temperature on Biochar Characteristics, Soil and Crop Response in Temperate Soils  

DEFF Research Database (Denmark)

At present, there is limited understanding of how biochar application to soil could be beneficial to crop growth in temperate regions and which biochar types are most suitable. Biochars (two feedstocks: willow, pine; three pyrolysis temperatures: 450 C, 550 C, 650 C) effect on nitrogen (N) availability, N use efficiency and crop yield was studied in northwestern European soils using a combined approach of process-based and agronomic experiments. Biochar labile carbon (C) fractions were determined and a phytotoxicity test, sorption experiment, N incubation experiment and two pot trials were conducted. Generally, biochar caused decreased soil NO3? availability and N use efficiency, and reduced biomass yields compared to a control soil. Soil NO3? concentrations were more reduced in the willow compared to the pine biochar treatments and the reduction increased with increasing pyrolysis temperatures, which was also reflected in the biomass yields. Woody biochar types can cause short-term reductions in biomass production due to reduced N availability. This effect is biochar feedstock and pyrolysis temperature dependent. Reduced mineral N availability was not caused by labile biochar C nor electrostatic NH4+/NO3? sorption. Hence, the addition of fresh biochar might in some cases require increased fertilizer N application to avoid short-term crop growth retardation.

Nelissen, Victoria; Ruysschaert, Greet

2014-01-01

90

Chemical spray pyrolysis of ?-In2S3 thin films deposited at different temperatures  

Science.gov (United States)

In2S3 thin films were deposited onto indium tin oxide-coated glass substrates by chemical spray pyrolysis while keeping the substrates at different temperatures. The structures of the sprayed In2S3 thin films were characterized by X-ray diffraction (XFD). The quality of the thin films was determined by Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy were used to explore the surface morphology and topography of the thin films, respectively. The optical band gap was determined based on optical transmission measurements. The indium sulfide phase exhibited a preferential orientation in the (0, 0, 12) crystallographic direction according to the XRD analysis. The phonon vibration modes determined by Raman spectroscopy also confirmed the presence of the In2S3 phase in our samples. According to SEM, the surface morphologies of the films were free of defects. The optical band gap energy varied from 2.82 eV to 2.95 eV.

Sall, Thierno; Mar Soucase, Bernab; Mollar, Miguel; Hartitti, Bouchaib; Fahoume, Mounir

2015-01-01

91

PYROLYSIS OF EMPTY FRUIT BUNCHES: INFLUENCE OF TEMPERATURE ON THE YIELDS AND COMPOSITION OF GASEOUS PRODUCT  

OpenAIRE

With the increasing concern on fossil fuel depletion and environmental problems, the utilization of renewable biomass resources is expected to play an important role in the future. Biomass can be converted into a variety of fuels and chemicals by different processes; one of which is pyrolysis that has been subjected to extensive research in recent years. In this study, pyrolysis of oil palm Empty Fruit Bunches (EFB) was investigated using a quartz fluidised-fixed bed reactor. The effects of p...

Mohamad Azri Sukiran; Loh Soh Kheang; Nasrin Abu Bakar; Choo Yuen May

2014-01-01

92

Mechanisms of dioxin formation from the high-temperature pyrolysis of 2-bromophenol.  

Science.gov (United States)

Brominated hydrocarbons are the most commonly used flame retardants. Materials containing brominated hydrocarbons are frequently disposed in municipal and hazardous waste incinerators as well as being subjected to thermal reaction in accidental fires. This results in the potential for formation of brominated dioxins and other hazardous combustion byproducts. In contrast to chlorinated hydrocarbons, the reactions of brominated hydrocarbons have been studied only minimally. As a model brominated hydrocarbon that may form brominated dioxins, we studied the homogeneous, gas-phase pyrolytic thermal degradation of 2-bromophenol in a 1-cm i.d., fused-silica flow reactor at a concentration of 90 ppm, with a reaction time of 2.0 s, and over a temperature range of 300 to 1000 degrees C. Observed products included dibenzo-p-dioxin (DD), 1-monobromodibenzo-p-dioxin (1-MBDD), 4-monobromodibenzofuran (4-MBDF), dibenzofuran (DF), naphthalene, bromonaphthalene, 2,4- and 2,6-dibromophenol, phenol, bromobenzene, and benzene. These results are compared and contrasted with previous results reported for 2-chlorophenol. At temperatures lower than 700 degrees C, formation of 2-bromophenoxyl radical, which decomposes through CO elimination to form a bromocyclopentadienyl radical, forms naphthalene and 2-bromonaphthalene through radical recombination/rearrangement reactions. However, unlike the results for 2-chlorophenol, where naphthalene is the major product, DD becomes the major product for the pyrolysis of 2-bromophenol. The formation of DD and 1-MBDD are attributed to radical-radical reactions involving 2-bromophenoxyl radical with the carbon- (bromine) centered radical and the carbon- (hydrogen) centered radical mesomers of 2-bromophenoxyl radical, respectively. The potential product, 4,6-dibromodibenzofuran (4,6-DBDF) for which the analogous product, 4,6-dichlorodibenzofuran (4,6 DCDF), was observed in the oxidation of 2-chlorophenol, was not detected. This is attributed to the pyrolytic conditions of our experiments (e.g., shorter reaction times and higher temperatures) that favor reaction intermediates that form DD and 1-MBDD. PMID:14717166

Evans, Catherine S; Dellinger, Barry

2003-12-15

93

Deoxygenation of the Baltic Sea during the last century.  

Science.gov (United States)

Deoxygenation is a global problem in coastal and open regions of the ocean, and has led to expanding areas of oxygen minimum zones and coastal hypoxia. The recent expansion of hypoxia in coastal ecosystems has been primarily attributed to global warming and enhanced nutrient input from land and atmosphere. The largest anthropogenically induced hypoxic area in the world is the Baltic Sea, where the relative importance of physical forcing versus eutrophication is still debated. We have analyzed water column oxygen and salinity profiles to reconstruct oxygen and stratification conditions over the last 115 y and compare the influence of both climate and anthropogenic forcing on hypoxia. We report a 10-fold increase of hypoxia in the Baltic Sea and show that this is primarily linked to increased inputs of nutrients from land, although increased respiration from higher temperatures during the last two decades has contributed to worsening oxygen conditions. Although shifts in climate and physical circulation are important factors modulating the extent of hypoxia, further nutrient reductions in the Baltic Sea will be necessary to reduce the ecosystems impacts of deoxygenation. PMID:24706804

Carstensen, Jacob; Andersen, Jesper H; Gustafsson, Bo G; Conley, Daniel J

2014-04-15

94

Deoxygenation of Lake Ikeda, Japan  

Science.gov (United States)

Lake Ikeda (Kagoshima prefecture, Japan) is a deep lake with a maximum depth of 233 m. Monitoring data of lake Ikeda exist since 1975. We have analyzed the long-term variability in the water conditions of Lake Ikeda. Recently, Lake Ikeda has exhibited the phenomenon of incomplete overturning because of climate warming. The concentrations of DO (dissolved oxygen) in the deepest parts of the lake have reduced. This phenomenon was observed to have started in the 1980s, and gradually, the deepest parts of the lake became anoxic. Later, the anoxic layer became thicker. Currently, winter mixing in Lake Ikeda reaches to depths of only 100 m. According to our simple estimation, the total volume of oxygen in Lake Ikeda will reduce from approximately 70% in the mid-1980s to 40% by the end of 2010. In addition to this phenomenon, the oxygen concentration appears to vary with several years oscillations. The depths to which mixing occurs depends on the severity of the winter, such as the air temperature during the winter season. The mixing period generally occurs in February; hence, the limnological year is considered to start in February. During our analysis period, the total DO mass showed high values in 1996, 2001, and 2003. Air temperature data obtained for regions near Lake Ikeda (the station name is Ibusuki) are used to clarify the cause of the high DO mass values in the three abovementioned years. During the period prior to the occurrence of the high DO mass in February 1996, i.e., in December 1995 and January 1996, the air temperature was low. Similarly, in 2001 and 2003, the air temperature was low in January (one month before the high DO mass was observed). In January 2001 and 2003, the AO (Atlantic Oscillation) index was negative. When the AO index is negative, there tends to be a greater movement of cold polar air into mid-latitudinal regions including Japan (Yamakawa, 2005). This movement induced a low air temperature in Ibusuki, and consequently, a high DO mass was observed in Lake Ikeda. On the other hand, the AO index was negative in December 1995 and January 1996. In addition, the WP (Western Pacific) index was also negative in the winter of 1995/96. When the WP index is negative, Japan experiences a cold winter (Koide and Kodera, 1999; Yasunaka and Hanawa, 2008). Therefore, the combination of the negative phase of AO and the negative phase of WP led to the occurrence of cold surges near Lake Ikeda, which in turn resulted in the high DO mass in February 1996. When DO concentration in the deep layer of the lake becomes higher caused winter mixing, we observe also a reduction in the DO concentration in the surface layer. The DO concentration in the surface layer sometimes decreased to 70%. In future, once Lake Ikeda will deep mixing during very cold winters, the DO concentration in the surface water might reduce largely.

Nagata, R.; Hasegawa, N.

2010-12-01

95

Synthesis and characterization of ZnO nano and micro structures grown by low temperature spray pyrolysis and vapor transport.  

Science.gov (United States)

In this work we present a systematic study of ZnO micro and nanostructures grown by spray pyrolysis (SP) and by physical vapour transport (PVT) on glass and c-sapphire substrates at low temperatures. Optimised growth conditions have allowed to obtain homogeneous ZnO nanolayers composed of quasi-spherical nanoparticles in the range 2 to 8 nm by spray pyrolysis, while by PVT the selected growth conditions allow to produce a wide variety of morphologies (tripods, grains, arrows and wires) of nano and microsize dimension. Grazing incidence X-ray diffraction, field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and energy dispersive X-ray spectroscopy (EDX) were used as characterization techniques in the investigation of structural, morphological and compositional nature of these nanostructures in relation with the growth method. PMID:22962824

Agouram, S; Bushiri, M J; Montenegro, D N; Reig, C; Martnez-Toms, M C; Muoz-Sanjos, V

2012-08-01

96

Kinetics of Increased Deformability of Deoxygenated Sickle Cells upon Oxygenation  

OpenAIRE

We have examined the kinetics of changes in the deformability of deoxygenated sickle red blood cells when they are exposed to oxygen (O2) or carbon monoxide. A flow-channel laser diffraction technique, similar to ektacytometry, was used to assess sickle cell deformability after mixing deoxygenated cells with buffer that was partially or fully saturated with either O2 or carbon monoxide. We found that the deformability of deoxygenated sickle cells did not regain its optimal value for several s...

Huang, Zhi; Hearne, Leigh; Irby, Cynthia E.; King, S. Bruce; Ballas, Samir K.; Kim-shapiro, Daniel B.

2003-01-01

97

Catalytic Oxidation and Deoxygenation of Renewables with Rhenium Complexes  

OpenAIRE

Transformation of renewables has received major research interest in recent years, opening up completely new research areas, in particular in the field of oxidation and deoxygenation. For the oxidation reaction, rhenium complexes, in particular methyltrioxorhenium, are well known for their potential as catalysts, but they are also potent catalysts for the deoxygenation reaction. The application of organometallic rhenium complexes in both the oxidation and deoxygenation reactions using a broad...

Korstanje, T. J.; Klein Gebbink, R. J. M.

2012-01-01

98

Temperature dependent grain-size and microstrain of CdO thin films prepared by spray pyrolysis method  

International Nuclear Information System (INIS)

CdO thin films on glass substrate were prepared by home built spray pyrolysis unit from aqueous solution of Cd(CH3COO)2.2H2O at different substrate temperatures. X-ray diffraction (XRD) studies indicate the formation of polycrystalline cubic CdO phase with preferential orientation along (111) plane. X-ray line broadening technique is adopted to study the effect of substrate temperature on microstructural parameters such as grain size and microstrain. Scanning electron microscopy (SEM) shows that the film prepared at 250 deg C consists of spherical shape grains with size in nanometer range and is comparable with the XRD studies. (author)

99

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

Science.gov (United States)

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 2000C, with heating rates from 5 to 450C/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 50C/s). The surface area and pore volume firstly increased with temperature and reached maximum at 1200C then reduced significantly at 2000C. Besides, they firstly increased with heating rate and then decreased slightly at heating rate of 450C/s when final temperature was no lower than 1200C. 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. PMID:25686544

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

2015-04-01

100

Lead retention by broiler litter biochars in small arms range soil: impact of pyrolysis temperature.  

Science.gov (United States)

Phosphorus-rich manure biochar has a potential for stabilizing Pb and other heavy metal contaminants, as well as serving as a sterile fertilizer. In this study, broiler litter biochars produced at 350 and 650 C were employed to understand how biochar's elemental composition (P, K, Ca, Mg, Na, Cu, Pb, Sb, and Zn) affects the extent of heavy metal stabilization. Soil incubation experiments were conducted using a sandy, slightly acidic (pH 6.11) Pb-contaminated (19906 mg kg(-1) total Pb primarily as PbCO(3)) small arms range (SAR) soil fraction (biochar. The Pb stabilization in pH 4.9 acetate buffer reached maximum at lower (2-10 wt %) biochar amendment rate, and 350 C biochar containing more soluble P was better able to stabilize Pb than the 650 C biochar. The 350 C biochar consistently released greater amounts of P, K, Mg, Na, and Ca than 650 C biochar in both unbuffered (pH 4.5 sulfuric acid) and buffered (pH 4.9 acetate) systems, despite 1.9-4.5-fold greater total content of the 650 C biochar. Biochars, however, did not influence the total extractable Pb over three consecutive equilibration periods consisting of (1) 1 week in pH 4.5 sulfuric acid (simulated leaching by rainfall), (2) 1 week in pH 4.9 acetate buffer (standard solution for toxicity characteristic leaching procedure), and (3) 1 h in pH 1.5 glycine at 37 C (in vitro bioaccessibility procedure). Overall, lower pyrolysis temperature was favorable for stabilizing Pb (major risk driver of SAR soils) and releasing P, K, Ca, and other plant nutrients in a sandy acidic soil. PMID:22548418

Uchimiya, Minori; Bannon, Desmond I; Wartelle, Lynda H; Lima, Isabel M; Klasson, K Thomas

2012-05-23

101

The influence of temperature on the yields of compounds existing in bio-oils obtained from biomass samples via pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The influence of temperature on the compounds existing in liquid products obtained from biomass samples via pyrolysis were examined in relation to the yield and composition of the product bio-oils. The product liquids were analysed by a gas chromatography mass spectrometry combined system. The bio-oils were composed of a range of cyclopentanone, methoxyphenol, acetic acid, methanol, acetone, furfural, phenol, formic acid, levoglucosan, guaiacol and their alkylated phenol derivatives. Thermal depolymerization and decomposition of biomass structural components, such as cellulose, hemicelluloses, lignin form liquids and gas products as well as a solid residue of charcoal. The structural components of the biomass samples mainly affect the pyrolytic degradation products. A reaction mechanism is proposed which describes a possible reaction route for the formation of the characteristic compounds found in the oils. The supercritical water extraction and liquefaction partial reactions also occur during the pyrolysis. Acetic acid is formed in the thermal decomposition of all three main components of biomass. In the pyrolysis reactions of biomass: water is formed by dehydration; acetic acid comes from the elimination of acetyl groups originally linked to the xylose unit; furfural is formed by dehydration of the xylose unit; formic acid proceeds from carboxylic groups of uronic acid; and methanol arises from methoxyl groups of uronic acid. (author)

Demirbas, Ayhan [Sila Science, Trabzon (Turkey)

2007-06-15

102

The effects of calcination temperature on the electrochemical performance of LiMnPO4 prepared by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

Research highlights: ? Carbon-coated LiMnPO4 cathode materials were prepared by ultrasonic spray pyrolysis. ? The effects of calcinations temperature on the microstructure and electrochemical performance of C-LiMnPO4 were investigated. ? X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that the calcination temperature had a strong influence on the morphology and crystallite size of the prepared final powder, and therefore the subsequent electrochemical performance of the material. ? The C-LiMnPO4 powders prepared at 650 oC exhibited excellent electrochemical performance with a discharge capacity of 118 mAh g-1. - Abstract: Carbon-coated LiMnPO4 powders were prepared by ultrasonic spray pyrolysis. The effects of calcination temperature on the microstructure and electrochemical performance of C-LiMnPO4 were investigated. X-ray diffraction (XRD) studies showed that the crystallite size varied with calcination temperature. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that the calcination temperature had a strong influence on the morphology of the prepared final powder, and therefore the subsequent electrochemical performance of the material. The C-LiMnPO4 powders prepared at 650 oC exhibited excellent electrochemical performance with a dictrochemical performance with a discharge capacity of 118 mAh g-1.

103

Ship board testing of a deoxygenation ballast water treatment.  

Science.gov (United States)

A ship board trial of a deoxygenation method for treating ballast water was carried out during a voyage from Southampton (United Kingdom) to Manzanillo (Panama). A nutrient solution added to two ballast tanks encouraged bacterial growth, resulting in a gradual change to an anoxic environment. Samples were taken from two treated tanks and two untreated tanks to assess changes in the abundance and viability of zooplankton, phytoplankton and bacteria. The work was carried out before the International Maritime Organization (IMO) standard was agreed so only a broad indication of whether the results achieved the standard was given. For the zooplankton, the standard would have been achieved within 5 or 7 days but the phytoplankton results were inconclusive. The biological efficacy was the result of the combination of several factors, including the treatment, pump damage and an increase in the water temperature during the voyage. PMID:17574278

McCollin, Tracy; Quilez-Badia, Gemma; Josefsen, Kjell D; Gill, Margaret E; Mesbahi, Ehsan; Frid, Chris L J

2007-08-01

104

Effect of stress on optical band gap of ZnO thin films with substrate temperature by spray pyrolysis  

International Nuclear Information System (INIS)

Zinc oxide (ZnO) thin films have been deposited with various substrate temperatures by spray pyrolysis method onto glass substrates. The effects of substrate temperature on the crystallization behavior and optical properties of the films have been studied. The evolution of strain and stress effects in ZnO thin films on glass substrate has been studied using X-ray diffraction. The films deposited at low substrate temperature have large compressive stress of 1.77 GPa, which relaxed to 1.47 GPa as the substrate temperature increased to 450 deg. C. Optical parameters such as optical transmittance, reflectance, dielectric constant, refractive index and energy band gap have been studied and discussed with respect to substrate temperature. All films exhibit a transmittance of about 85% in the visible region. It was found that the compressive stress in the films causes a decrease in the optical band gap.

105

Pyrolysis temperature-dependent changes in dissolved phosphorus speciation of plant and manure biochars  

Science.gov (United States)

Pyrolysis of plant and animal wastes produces a complex mixture of phosphorus species in amorphous, semi-crystalline, and crystalline inorganic phases, organic (char) components, and within organo-mineral complexes. In order to understand the solubility of different phosphorus species, plant (cotto...

106

Effects of Biochar Feedstock and Pyrolysis Temperature on Growth of Corn, Soybean, Lettuce and Carrot  

Science.gov (United States)

Biochar, the carbon-rich material remaining after pyrolysis (low oxygen) of cellulosic feedstocks, has the potential as a soil amendment to sequester carbon, improve soil water-holding capacity, and increase nutrient retention thereby enhancing soil conditions to benefit plant gr...

107

ReaxFF molecular dynamics simulations of the initial pyrolysis mechanism of unsaturated triglyceride.  

Science.gov (United States)

To understand the impact of C?=?C double bonds in acyl chains of unsaturated triglycerides on the reaction mechanism and product composition in their initial pyrolysis process, ReaxFF molecular dynamics simulations were carried out using a molecular model, trilinolenin, at temperatures of 2000, 2250, and 2500 K. Analyses indicated that the observed pyrolysis mechanisms of unsaturated triglyceride are nearly identical to the saturated triglyceride, and the pyrolysis products also include alkanes, alkenes, alkadienes, aromatics, oxygenated species, CO?, and H?. The formation of intermediates and products is a sequential process. Three C--O bonds in trilinolenin molecule are usually successive dissociated first, leading to the formation of unsaturated C?H? radical and straight-chain C??H??O? (RCOO) radicals. Following that, the deoxygenated alkenyl chain is produced through decarboxylation of RCOO??radicals with consequent release of CO?. The resulting hydrocarbon radicals undergo a variety of disproportionation, isomerization, and hydrogen-transfer reactions, yielding straight and branched-chain hydrocarbons. It was found that the scission of C--O bond and decarboxylation should preferentially occur before the cleavage of the C--C bond ? to the C?=?C bond in the initial decomposition process of unsaturated trilinolenin. In addition, the formation of cyclic hydrocarbons could proceed through intramolecular cyclization mechanisms, including non-radical electrocyclic, biradical cyclization and cyclization of alkenyl radical, which are inconsistent with previously proposed bimolecular Diels-Alder addition mechanisms. More rapid pyrolysis of trilinolenin would occur at higher temperatures without significantly affecting the apparent reaction mechanisms of trilinolenin pyrolysis in the considered temperature range. Aromatic ring structures are observed to be stable after formation and do not decay within the 500 ps simulation period. PMID:24567153

Zhang, Zhiqiang; Yan, Kefeng; Zhang, Jilong

2014-03-01

108

Effect of substrate temperature on structure and optical properties of Co3O4 films prepared by spray pyrolysis technique  

Science.gov (United States)

Polycrystalline Co3O4 films of spinel cubic phase were prepared by spray pyrolysis on amorphous substrate. The deposition time was kept constant (30min) with variable ranges of substrate temperature (573-723 K). The structural and optical properties of films were studied. The average crystallite size calculated by Scherrer's equation was found to increase as substrate temperature increased. Very small particle size was achieved. Even at the highest deposition temperature, the size did not exceed 11.6nm. The average crystallite size obtained from AFM photos was ranged in from 182 to 248nm which reveals the presence of agglomerates. Optical data were recorded in the wavelength range 300-2500nm. A considerable difference in transmittance was observed for films prepared at different substrate temperatures. The absorption coefficient was measured and then correlated with the photon energy to estimate the energy gap, which was the value of the spinel phase with a direct transition

Abbas, S. Z.; Aboud, A. A.; Irfan, M.; Alam, S.

2014-06-01

109

Preconversion catalytic deoxygenation of phenolic functional groups. Quarterly technical progress report, October 1--December 31, 1995  

Energy Technology Data Exchange (ETDEWEB)

Recent research in the author`s laboratory has established the viability of the catalytic deoxygenation of phenols by Co monoxide. The deoxygenation of phenols is a problem of both fundamental and practical importance. The deoxygenation of phenols to arenes is a conceptually simple, yet a very difficult chemical transformation to achieve. The phenolic C-O bond energy of 103 kcal/mol is as strong as a benzene C-H bond and over 10 kcal/mol stronger than the C-O bonds of methanol or ethanol. Catalytic hydrodeoxygenation (HDO) of phenols over sulfided Mo/{gamma}-Al{sub 2}O{sub 3}, Ni-Mo/{gamma}-Al{sub 2}O{sub 3}, Co-Mo/{gamma}-Al{sub 2}O{sub 3} or other supported metal oxide catalysts can be achieved, at exceedingly high hydrogen pressures and temperature. Arene ring hydrogenation generally competes effectively with hydrodeoxygenation, and was found to occur an order of magnitude faster than HDO. As a consequence, most of the hydrogen is consumed in hydrogenation of the aromatic rings. HDO catalysts are easily poisoned. The inefficiency of catalysts for phenol deoxygenation in the presence of hydrogen can be attributed to the absence of a low energy mechanistic pathway for the hydrogenolysis of the strong phenol C-O bond. The authors are currently studying new transition metal catalysts for the efficient and selective deoxygenation of phenols using the Co/Co{sub 2} couple to remove phenolic oxygen atoms. The paper describes recent results on the mechanism of Co insertion into metal-oxygen bonds of phenoxides.

Kubiak, C.P.

1996-07-01

110

Nitrogen release during high temperature pyrolysis of coals and catalytic role of calcium in N{sub 2} formation  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of 10 coals with carbon contents of less than 80 wt%(daf) has been studied with a fixed bed quartz reactor to examine mainly nitrogen release from char-N without volatile matters. When temperature is raised from 1000 to 1350{degree}C, N{sub 2} yield increases but char-N decreases for all the coals used. There is a strong reverse correlation between N{sub 2} and char-N, which points out that most of N{sub 2} arises from char-N via solid phase reactions. NH{sub 3} is also formed from char-N at high temperatures of {ge} 1000{degree}C. In the pyrolysis of low rank coals, demineralization by HCl washing increases yields of tar-N, HCN and char-N, but decreases NH{sub 3} and N{sub 2}. The addition of 3 wt% Ca to the demineralized coals shows almost the reverse effect. The XRD measurements after pyrolysis at 1000 1350{degree}C reveal that the Ca exists predominantly as CaO with the average crystallite size of 25 65 nm and promotes carbon crystallization. As the extent of crystallized carbon increases, N{sub 2} yield increases remarkably. It is likely that the highly dispersed CaO catalyzes efficiently conversion reactions of char-N to N{sub 2} in the process of carbon crystallization. The reaction mechanism is discussed in term of interactions between CaO particles and char-N. 18 refs., 10 figs., 5 tabs.

Tsubouchi, N.; Ohtsuka, Y. [Tohoku University, Sendai (Japan). Institute of Multidisciplinary Research for Advanced Materials, Research Center for Sustainable Materials Engineering

2002-12-01

111

Effect of demineralization on yield and composition of the volatile products evolved from temperature-programmed pyrolysis of Beypazari (Turkey) Oil Shale  

Energy Technology Data Exchange (ETDEWEB)

In this study, the effect of the mineral matter of Beypazari Oil Shale on the conversion of organic carbon of oil shale into volatile hydrocarbon, polycyclic aromatic hydrocarbons (asphaltenes, preasphaltenes) and carbon in solid residue was investigated. Kerogen was isolated by successive HCl, HNO{sub 3} and HF treatments. A series of temperature-programmed pyrolysis operation was performed with raw Beypazari Oil Shale, and each product of every demineralization process. A carbon balance of the pyrolysis process was established by determination of the recovery of total organic carbon as organic products, and carbon remaining in the reactor because of the coking reactions. The removal of the material soluble in HCl washing affected the conversion of organic materials in the pyrolysis reactions. Alkali and alkaline earth metal cations affect the reactivity of oil shales and the leaching of these mineral matters with HCl caused a slightly decrease in the conversion to volatile hydrocarbons. The removal of pyrites with HNO{sub 3} did not affect the reactivity of the organic material in pyrolysis. But, removal of the material soluble in HF increased the conversion in pyrolysis reactions. It can be explained by the inhibitive effect of the silicate minerals. Complete removal of mineral matrix and isolation of kerogen increased the driving force for heat transfer since more heat was transferred from outside towards the inside of the oil shale particles, thus pyrolysis reaction might have occurred with ease and diffusion limitation might have decreased due to absence of mineral matrix.

Ballice, Levent [University of Ege, Faculty of Engineering, Department of Chemical Engineering, 35100 Bornova, Izmir (Turkey)

2005-03-25

112

Hydrogen-rich gas production from waste plastics by pyrolysis and low-temperature steam reforming over a ruthenium catalyst  

International Nuclear Information System (INIS)

Operating conditions for low-temperature pyrolysis and steam reforming of plastics over a ruthenium catalyst were investigated. In the range studied, the highest gas and lowest coke fractions for polystyrene (PS) with a 60 g h-1 scale, continuous-feed, two-stage gasifier were obtained with a pyrolyzer temperature of 673 K, steam reforming temperature of 903 K, and weight hourly space velocity (WHSV) of 0.10 g-sample g-catalyst-1 h-1. These operating conditions are consistent with optimum conditions reported previously for polypropylene. Our results indicate that at around 903 K, the activity of the ruthenium catalyst was high enough to minimize the difference between the rates of the steam reforming reactions of the pyrolysates from polystyrene and polypropylene. The proposed system thus has the flexibility to compensate for differences in chemical structures of municipal waste plastics. In addition, the steam reforming temperature was about 200 K lower than the temperature used in a conventional Ni-catalyzed process for the production of hydrogen. Low-temperature steam reforming allows for lower thermal input to the steam reformer, which results in an increase in thermal efficiency in the proposed process employing a Ru catalyst. Because low-temperature steam reforming can be also expected to reduce thermal degradation rates of the catalyst, the pyrolysis-steam reforming process with a Ru catalyst has the potential for use in small-sclyst has the potential for use in small-scale production of hydrogen-rich gas from waste plastics that can be used for power generation.

113

Liquefaction of beypazari oil shale by pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Beypazari oil shale was subjected to conventional and free falling pyrolysis at different temperatures to investigate optimum liquefaction temperatures. The oils obtained were characterized by GC, 1HNMR, IR and size exclusion chromatography to follow the molecular changes induced by the pyrolysis. Free falling pyrolysis gave the maximum degree of conversion of 61.9% at 873 K, whereas conventional pyrolysis gave a degree of conversion of 50.5% at 773 K. Conventional pyrolysis gave less n-alkenes-1 than that obtained from free falling pyrolysis at similar temperature. Polymerization reactions are predominant during conventional pyrolysis due to the longer reaction time. In contrast to conventional pyrolysis, more cracking reactions occurred during the free falling pyrolysis.

Olukcu, Nuray [Petrochemical Technology Department, Dokuz Eylul University, IMYO, 35150 Izmir (Turkey); Yanik, Jale; Saglam, Mehmet; Yuksel, Mithat [Department of Chemistry, Ege University, 35100 Izmir (Turkey)

2002-07-01

114

Effect of the flame temperature on the characteristics of zirconium oxide fine particle synthesized by flame assisted spray pyrolysis  

Science.gov (United States)

Zirconium oxide fine particles were synthesized by flame assisted spray pyrolysis using zirconium chloride solution as precursor. Propane gas and air were used as a fuel and an oxidizer, respectively. The ratio of flow rate of oxidizer and fuel was maintained constant at 10:1 to ensure a complete combustion. Increasing fuel flow rate led to the increase of temperature distribution in the flame reactor. The intensity of XRD patterns increased with temperature and precursor concentration. Phase composition of zirconium oxide produced by this process consisted of monoclinic and tetragonal phases. The volume fraction of monoclinic phase of zirconium oxide increased with temperature and precursor concentration. The morphology particles observed by SEM resulted in spherical particles with size in the submicron range depending on the precursor concentration.

Widiyastuti, W.; Machmudah, Siti; Nurtono, Tantular; Winardi, Sugeng

2013-09-01

115

Modeling of biomass pyrolysis  

International Nuclear Information System (INIS)

The fuels used in industry and power sector for the last two decades have become expensive. As a result renewable energy source have been emerging increasingly important, of these, biomass appears to be the most applicable in the near future. The pyrolysis of biomass plays a key role amongst the three major and important process generally encountered in a gas producer, namely, pyrolysis, combustion and reduction of combustion products. Each biomass has its own pyrolysis characteristics and this important parameters must be known for the proper design and efficient operation of a gasification system. Thermogravimetric analysis has been widely used to study the devolatilization of solid fuels, such as biomass. It provides the weight loss history of a sample heated at a predetermined rate as a function of time and temperature. This paper presents the experimental results of modelling the weight loss curves of the main biomass components i.e. cellulose, hemicellulose and lignin. Thermogravimetric analysis of main components of biomass showed that pyrolysis is first order reaction. Furthermore pyrolysis of cellulose and hemicelluloe can be regarded as taking place in two stages, for while lignin pyrolysis is a single stage process. This paper also describes the Thermogravimetric Analysis (TGA) technique to predict the weight retained during pyrolysis at any temperature, for number of biomass species, such as cotton stalk, bagasse ad graoundnut shell. (author)d graoundnut shell. (author)

116

Pyrolysis of Coal  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a review of relevant literature on coal pyrolysis.Pyrolysis, as a process technology, has received considerable attention from many researchers because it is an important intermediate stage in coal conversion.Reactions parameters as the temperature, pressure, coal particle size, heating rate, soak time, type of reactor, etc. determine the total carbon conversion and the transport of volatiles and therebythe product distribution. Part of the possible environmental pollutants could be removed by optimising the pyrolysis conditions. Therefore, this process will be subsequently interesting for coal utilization in the future

Ra?enovi?, A.

2006-07-01

117

Study of hydrazine deoxygenation under the condition of steam generator wet lay up  

International Nuclear Information System (INIS)

The method of hydrazine deoxygenation catalysed by hydroquinone under the condition of Steam Generator (SG) wet lay up is discussed. The results show that the temperature, the using dosages of both hydroquinone as catalyst and hydrazine have an influence on the rate and the efficiency of deoxygenation. When the quantity of hydrazine is 6 times as much as the concentration of dissolved oxygen, the quantity of hydroquinone is slightly more than 10 ?g/L and the temperature is at 35 degree C, the content of dissolved oxygen can be below 100 ?g/L. When the quantity of hydroquinone is more than 50 ?g/L, the content of dissolved oxygen can be below 100 ?g/L after 3 minutes and below 10 ?g/L after 20 minutes

118

Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360?C contained zinc oxynitrides, CO{sub 3}, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500?C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140?C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4??10{sup 17}?eV{sup ?1}?cm{sup ?3} due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm{sup 2}/V s, the subthreshold slope was 0.3 V dec{sup ?1}, and an on-set close to the ideal value of 0?V was achieved.

Ortel, Marlis; Balster, Torsten; Wagner, Veit [School of Engineering and Science, Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany)

2013-12-21

119

Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis  

Science.gov (United States)

Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360 C contained zinc oxynitrides, CO3, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500 C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140 C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4 1017 eV-1 cm-3 due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm2/V s, the subthreshold slope was 0.3 V dec-1, and an on-set close to the ideal value of 0 V was achieved.

Ortel, Marlis; Balster, Torsten; Wagner, Veit

2013-12-01

120

Chemical composition and temperature dependent performance of ZnO-thin film transistors deposited by pulsed and continuous spray pyrolysis  

International Nuclear Information System (INIS)

Zinc oxide thin film transistors (TFTs) deposited by continuous and pulsed spray pyrolysis were investigated to analyze process kinetics which make reduction of process temperature possible. Thus, fluid mechanics, chemical composition, electrical performance, and deposition and annealing temperature were systematically analyzed. It was found that ZnO layers continuously deposited at 360?C contained zinc oxynitrides, CO3, and hydro carbonate groups from pyrolysis of basic zinc acetate. Statistically, every second wurtzite ZnO unit cell contained an impurity atom. The purity and performance of the ZnO-TFTs increased systematically with increasing deposition temperature due to an improved oxidation processes. At 500?C the zinc to oxygen ratio exceeded a high value of 0.96. Additionally, the ZnO film was not found to be in a stabilized state after deposition even at high temperatures. Introducing additional subsequent annealing steps stabilizes the film and allows the reduction of the overall thermal stress to the substrate. Further improvement of device characteristics was obtained by pulsed deposition which allowed a more effective transport of the by-products and oxygen. A significant reduction of the deposition temperature by 140?C was achieved compared to the same performance as in continuous deposition mode. The trap density close to the Fermi energy could be reduced by a factor of two to 4??1017?eV?1?cm?3 due to the optimized combustion process on the surface. The optimization of the deposition processes made the fabrication of TFTs with excellent performance possible. The mobility was high and exceeded 12 cm2/V s, the subthreshold slope was 0.3 V dec?1, and an on-set close to the ideal value of 0?V was achieved

121

On the application of hydrazine for deoxygenation of WWER primary circuit water coolant during oritages  

International Nuclear Information System (INIS)

Possibility and conditions of effective hydrazine usage for correction of coolant composition of the WWER first circuit during outages for decreasing water corrosivity was considered. Experimental investigations have confirmed possibility of hydrazine usage for deoxygenation of the irradiated water which interacts with nitrates and nitrites formed as a result of ammonia oxidation. Taking account of catalytic effect of ionizing radiation, coolant treatment with hydrazine during outages may be performed at low temperature

122

Bench-Scale Design of a Low-Temperature Pyrolysis and Steam Reforming System for the Treatment of Uranium-Bearing Spent TBP  

International Nuclear Information System (INIS)

Spent TBP, a combustible waste solvent, is not readily incinerated due to problems associated with condensation of phosphoric acid. A two-stage pyrolysis system that consists of a low-temperature pyrolysis at ? 450 .deg. C and a higher-temperature steam-assisted pyrolysis at ? 800 .deg .C has been proposed as an alternative oxidation technology for the destruction of spent TBP. Off-gas from this two-stage pyrolysis system includes various unburned hydrocarbons (UHCs) as well as complete-steam reforming products, CO and H2, which should be substantially oxidized prior to emission into the atmosphere. Catalytic oxidation is considered as an advantageous and safe treatment method for UHCs. A Pt-based honeycomb monolith is considered to be an effective combustion catalyst for UHCs. Numerous studies on platinum monolith honeycomb reactors have focused on catalytic combustion of a single fuel. The present study investigated the catalytic oxidation of a mixture of various UHCs from the proposed two-stage pyrolysis of waste TBP, in a platinum monolith honeycomb reactor. A wide ranging parametric model study was performed to establish proper conditions of a platinum monolith honeycomb reactor for the bench-scale system design

123

Study of surface cleaning methods and pyrolysis temperatures on nanostructured carbon films using x-ray photoelectron spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of diblock copolymers are of interest for a variety of electrical/electronic applications due to their chemical inertness, high-temperature insensitivity, very high surface area, and tunable electrical resistivity over a wide range [Kulkarni et al., Synth. Met. 159, 177 (2009)]. Because of their high porosity and associated high specific surface area, controlled surface cleaning studies are important for fabricating electronic devices from these films. In this study, quantification of surface composition and surface cleaning studies on ns-C films synthesized by carbonization of diblock copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) at two different temperatures were carried out. X-ray photoelectron spectroscopy was used for elemental analysis and to determine the efficacy of various surface cleaning methods for ns-C films and to examine the polymer residues in the films. The in-situ surface cleaning methods included HF vapor treatment, vacuum annealing, and exposure to UV-ozone. Quantitative analysis of high-resolution XPS scans showed 11 at. % nitrogen was present in the films pyrolyzed at 600 Degree-Sign C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 Degree-Sign C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen subpeaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic clusters, suggesting higher graphitization with increasing pyrolysis temperature. Of the surface cleaning methods investigated, in-situ annealing of the films at 300 Degree-Sign C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

Kerber, Pranita; Porter, Lisa M.; McCullough, Lynne A.; Kowalewski, Tomasz; Engelhard, Mark; Baer, Donald [Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Chemistry Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 (United States); Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

2012-11-15

124

Effects of pyrolysis temperature on soybean stover- and peanut shell-derived biochar properties and TCE adsorption in water.  

Science.gov (United States)

Conversion of crop residues into biochars (BCs) via pyrolysis is beneficial to environment compared to their direct combustion in agricultural field. Biochars developed from soybean stover at 300 and 700 C (S-BC300 and S-BC700, respectively) and peanut shells at 300 and 700 C (P-BC300 and P-BC700, respectively) were used for the removal of trichloroethylene (TCE) from water. Batch adsorption experiments showed that the TCE adsorption was strongly dependent on the BCs properties. Linear relationships were obtained between sorption parameters (K(M) and S(M)) and molar elemental ratios as well as surface area of the BCs. The high adsorption capacity of BCs produced at 700 C was attributed to their high aromaticity and low polarity. The efficacy of S-BC700 and P-BC700 for removing TCE from water was comparable to that of activated carbon (AC). Pyrolysis temperature influencing the BC properties was a critical factor to assess the removal efficiency of TCE from water. PMID:22721877

Ahmad, Mahtab; Lee, Sang Soo; Dou, Xiaomin; Mohan, Dinesh; Sung, Jwa-Kyung; Yang, Jae E; Ok, Yong Sik

2012-08-01

125

Leidenfrost temperature related CVD-like growth mechanism in ZnO-TFTs deposited by pulsed spray pyrolysis  

Science.gov (United States)

Zinc oxide thin films were prepared by pulsed spray pyrolysis (SP) from aqueous zinc acetate precursor solution. The deposition behavior of the solution with regard to the pool boiling curve of the solvent was investigated to gain insights of the deposition mechanism which leads to homogeneous and reproducible ZnO layers. The Leidenfrost effect was found to play an important role since the Leidenfrost temperature has to be exceeded to form high quality layers. It is concluded that 3D nucleation of ZnO nano-crystals takes place out of the gaseous phase by a CVD-like process on ITO as well as on SiO2 substrates. Crystal orientation and surface roughness of the zinc oxide layer are found to depend strongly on the substrate. An increasing grain size with film thickness is observed. These findings were utilized to fabricate and investigate the semiconducting properties of the films in ZnO thin film transistors (TFTs). The mobility exceeded 12 cm2 V-1 s-1, the on-set was at 1 V and the on-off current ratio was found to be higher than 108. Hence the morphology and the electrical parameters of the ZnO films deposited by pulsed spray pyrolysis from non-toxic aqueous zinc acetate solution above the Leidenfrost point show excellent properties for electronic applications.

Ortel, Marlis; Wagner, Veit

2013-01-01

126

Effect of gamma-ray irradiation on the deoxygenation of salt-containing water using hydrazine  

International Nuclear Information System (INIS)

In spent fuel pools at the Fukushima Daiichi nuclear power plant, hydrazine was added to salt-containing water in order to reduce dissolved oxygen. Hydrazine is known to reduce dissolved oxygen in high-temperature pure water, but its deoxygenation behavior in salt-containing water at ambient temperature in the presence of radiation is unknown. Deoxygenation using hydrazine in salt-containing water was thus investigated using a 60Co gamma-ray source and artificial seawater at room temperature. Water samples containing a small amount of hydrazine were irradiated at dose rates of 100 - 10,000 Gy/h. The concentration of dissolved oxygen in the water samples was measured before and after irradiation. Notably, a decrease in the dissolved oxygen was only observed after irradiation, and the dissolved oxygen concentration decreased with increasing dose rate and irradiation time. The rate of decrease in the amount of dissolved oxygen using hydrazine was slow in the presence of salts. Kinetic considerations suggested that the deoxygenation of the salt-containing water exposed to gamma-ray irradiation using hydrazine was suppressed by chloride ions. (author)

127

Room-temperature ferromagnetism in Sn1-xMnxO2 nanocrystalline thin films prepared by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

Sn1-xMnxO2 (x=0.01-0.05) thin films were synthesized on quartz substrate using an inexpensive ultrasonic spray pyrolysis technique. The influence of doping concentration and substrate temperature on structural and magnetic properties of Sn1-xMnxO2 thin films was systematically investigated. X-ray diffraction (XRD) studies of these films reflect that the Mn3+ ions have substituted Sn4+ ions without changing the tetragonal rutile structure of pure SnO2. A linear increase in c-axis lattice constant has been observed with corresponding increase in Mn concentration. No impurity phase was detected in XRD patterns even after doping 5 at% of Mn. A systematic change in magnetic behavior from ferromagnetic to paramagnetic was observed with increase in substrate temperature from 500 to 700 deg. C for Sn1-xMnxO2 (x=0.01) films. Magnetic studies reveal room-temperature ferromagnetism (RTFM) with 3.61x10-4 emu saturation magnetization and 92 Oe coercivity in case of Sn1-xMnxO2 (x=0.01) films deposited at 500 deg. C. However, paramagnetic behavior was observed for the films deposited at a higher substrate temperature of 700 deg. C. The presence of room-temperature ferromagnetism in these films was observed to have an intrinsic origin and could be obtained by controlling the substrate temperature and Mn doping g the substrate temperature and Mn doping concentration.

128

Explosion protection in furnaces for combined pyrolysis and low-temperature gasification; Explosionsschutz an Schwelgas-Pyrolyse-Oefen  

Energy Technology Data Exchange (ETDEWEB)

Metal racks used in varnishing plants must be cleansed before reuse. There are several techniques for doing this, e.g. mechanical stripping of the varnish (sand blasting, high-pressure water jets), chemical removal, and thermal removal (fluidized bed and pyrolysis/low-temperature gasification). The residues are classified as toxic waste. Since the coming into force of the Technical Rule on Waste Management in 1990, the thermal processes have gained an economic advantage, owing to the low volume of residues and the minimisation of emissions by post-combustion of the pyrolysis gases. The article goes into detail about the available stripping processes, post-combustion processes and emission reduction measures. The mechanisms of low-temperature carbonisation and combustion re described in consideration of the type and volume of the varnish to be removed, the process temperatures and the conversion rates if inertisation measures are carried out at the same time. The causes of explosions and the resulting explosion protection concepts are discussed. (orig.) [Deutsch] Metallische Lackiergehaenge aus Lackieranlagen muessen fuer ihre Wiederverwendung von den anhaftenden Lackrueckstaenden gesaeubert werden. Hierzu kommen verschiedene Entlackungsverfahren zur Anwendung, z.B. die mechanische Entlackung (Sandstrahlen, Wasserstrahlhochdruckreinigung), die chemische Entlackung (Abbeiztechnik) und die thermische Entlackung (Wirbelbett- und Pyrolyse-Schwelgaskammerverfahren). Die verbleibenden Rueckstaende muessen als Sondermuell entsorgt werden. Mit Inkrafttreten der TA Abfall 1990 haben die thermischen Verfahren wegen der Reduzierung des anfallenden Volumens an Sondermuell und der Optimierung des Emissionsschutzes durch Verbrennen der entstehenden Pyrolyse-Schwelgase in der der Wirbelbett- bzw. Schwelgaskammer nachgeschalteten thermischen Nachverbrennung an wirtschaftlicher Bedeutung gewonnen. Im Beitrag werden die verschiedenen Verfahrensweisen der thermischen Entlackung erlaeutert, und es wird auf die angewendeten Nachverbrennungsverfahren und die Emissionsminimierung eingegangen. Darueber hinaus zeigt er die in den Anlagen zeitlich ablaufenden Verschwelungs- und Verbrennungsmechanismen unter Beruecksichtigung der Art und Menge des zu verschwelenden Lackes, der zu fahrenden Prozesstemperaturen und -umsetzungen bei gleichzeitiger Durchfuehrung von Inertisierungsmassnahmen auf. Die Explosionsursachen und die daraus abzuleitenden Explosionsschutzkonzepte werden diskutiert. (orig.)

Redeker, T. [IBExU, Inst. fuer Sicherheitstechnik GmbH, Freiberg (Germany); Zimmermann, K. [IBExU, Inst. fuer Sicherheitstechnik GmbH, Freiberg (Germany); Brandes, E. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)

1996-10-01

129

Influence of pyrolysis temperature and heating rate on the production of bio-oil and char from safflower seed by pyrolysis, using a well-swept fixed-bed reactor  

Energy Technology Data Exchange (ETDEWEB)

In this study, fast pyrolysis of safflower seed (Carthamus tinctorius L.) was investigated with the aim to study the product distribution and their chemical compositions and to identify optimum process conditions for maximizing the bio-oil yield. Experiments were performed in a well-swept resistively heated fixed-bed reactor under nitrogen atmosphere. The maximum oil yield of 54% was obtained at the final pyrolysis temperature of 600 C, sweeping gas flow rate of 100 cm{sup 3} min{sup -} {sup 1} and heating rate of 300 C min{sup -} {sup 1} in a fixed-bed reactor. The elemental analysis and calorific value of the bio-oil were determined and compared with diesel fuel and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques (IR, GC/MS, simulated distillation). The char was characterized by elemental, BET surface area and SEM analyses. (author)

Onay, Ozlem [Porsuk Vocational School, Anadolu University, 26470 Eskisehir (Turkey)

2007-05-15

130

Effect of Substrate Temperature on the Growth of Polycrystalline ZnS Thin Films Prepared by Spray Pyrolysis Technique  

Directory of Open Access Journals (Sweden)

Full Text Available ZnS thin films on glass substrate have been prepared by home built spray pyrolysis technique at 220, 250 and 280C. Aqueous solution of 50 mL containing zinc acetate dihydrate and thiourea salts of 1:1 M is sprayed as fine mist at a pressure of 2 kg cm-2 with flow rate of 3 mL min-1 on preheated glass substrate. Film obtained at 220C found to be amorphous and polycrystalline at 250 and 280C with preferential orientation along (111 plane. X-ray line broadening technique is utilized to determine the grain size and microstrain of the ZnS film. Compositional studies indicate the presence of oxygen for the film prepared at 250C. The effect of substrate temperature on crystalline structure, surface morphology and composition were analyzed and reported.

R. Chandiramouli

2012-01-01

131

Hydrotreating of fast pyrolysis oils from protein-rich pennycress seed presscake  

Science.gov (United States)

The fast pyrolysis oils produced from proteinaceous biomass, such as pennycress presscake differ significantly from those produced from biomass with mostly lignocellulosic composition. Those from proteinaceous biomass tend to be deoxygenated, contain more nitrogen, be less acidic and be more stable...

132

Temperature dependence of the photoluminescence spectra of CdS: In thin films prepared by the spray pyrolysis technique  

Energy Technology Data Exchange (ETDEWEB)

Indium doped cadmium sulfide thin films (CdS:In) are prepared by the spray pyrolysis technique on glass substrates using a home-made spraying system at a substrate temperature T{sub s}=490 C. The photoluminescence (PL) spectra are recorded at different temperatures in the range 24160 K. Two broad peaks were observed; a strong one in the visible region centered on E?2.0 eV and a weak one in the infrared region centered on E?1.06 eV. The first one is deconvoluted into two Gaussian peaks corresponding to the yellow and red bands, and the second one is deconvoluted into one Gaussian peak corresponding to the infrared band. A strong quenching of the PL intensity with temperature is observed after T=60 K for the yellow and infrared bands and after T=90 K for the red band. The activation energy E{sub a} was estimated by using the Arrhenius plot for the different bands. The estimated values for the three bands lie in the range E{sub a}?23.427.3 meV. The peak positions of the yellow and red bands are red-shifted after T=90 K, while the peak position of the infrared band is blue shifted in the whole temperature range. The full width at half maximum (FWHM) for the three bands increases with temperature. According to these findings the three bands are explained in terms of bound excitons. -- Highlights: The photoluminescence (PL) of sprayed CdS:In thin films is recorded at different temperatures. The PL spectrum is deconvoluted to three Gaussian peaks corresponding to yellow, red and infrared bands. The decrease of the PL intensity with temperature for these bands has similar behaviors. The yellow and red bands are red-shifted with temperature, but the infrared band is blue-shifted. From the Arrhenius plots the activation energy is estimated.

Ikhmayies, Shadia J., E-mail: shadia_ikhmayies@yahoo.com [Al Isra University, Faculty of Information Technology, Department of Basic Sciences-Physics, Amman 16197 (Jordan); Ahmad-Bitar, Riyad N., E-mail: riyad_b@yahoo.com [University of Jordan, Faculty of Science, Physics Department, Amman 1192 (Jordan)

2013-10-15

133

Temperature dependence of the photoluminescence spectra of CdS: In thin films prepared by the spray pyrolysis technique  

International Nuclear Information System (INIS)

Indium doped cadmium sulfide thin films (CdS:In) are prepared by the spray pyrolysis technique on glass substrates using a home-made spraying system at a substrate temperature Ts=490 C. The photoluminescence (PL) spectra are recorded at different temperatures in the range 24160 K. Two broad peaks were observed; a strong one in the visible region centered on E?2.0 eV and a weak one in the infrared region centered on E?1.06 eV. The first one is deconvoluted into two Gaussian peaks corresponding to the yellow and red bands, and the second one is deconvoluted into one Gaussian peak corresponding to the infrared band. A strong quenching of the PL intensity with temperature is observed after T=60 K for the yellow and infrared bands and after T=90 K for the red band. The activation energy Ea was estimated by using the Arrhenius plot for the different bands. The estimated values for the three bands lie in the range Ea?23.427.3 meV. The peak positions of the yellow and red bands are red-shifted after T=90 K, while the peak position of the infrared band is blue shifted in the whole temperature range. The full width at half maximum (FWHM) for the three bands increases with temperature. According to these findings the three bands are explained in terms of bound excitons. -- Highlights: The photoluminescence (PL) of sprayed CdS:In thin films is recorded at different temperatures. The PL spectrum is deconvoluted to three Gaussian peaks corresponding to yellow, red and infrared bands. The decrease of the PL intensity with temperature for these bands has similar behaviors. The yellow and red bands are red-shifted with temperature, but the infrared band is blue-shifted. From the Arrhenius plots the activation energy is estimated

134

The impacts of pyrolysis temperature and feedstock type on biochar properties and the effects of biochar application on the properties of a sandy loam  

Science.gov (United States)

The production of biochar and its application to soil has the potential to make a significant contribution to climate change mitigation whilst simultaneously improving soil fertility, crop yield and soil water-holding capacity. Biochar is produced from various biomass feedstock materials at varying pyrolysis temperatures, but relatively little is known about how these parameters affect the properties of the resultant biochars and their impact on the properties of the soils to which they are subsequently applied. Salix viminalis, M. giganteus and Picea sitchensis feedstocks were chipped then sieved to 2 - 5 mm, oven dried to constant weight, then pyrolyzed at 350, 500, 600 and 800 C in a nitrogen-purged tube furnace. Biochar yields were measured by weighing the mass of each sample before and after pyrolysis. Biochar hydrophobicity was assessed by using a goniometer to measure water-droplet contact-angles. Cation-exchange-capacity (CEC) was measured using the ammonium acetate method. Biochars were also produced in a rotary kiln from softwood pellets at 400, 500, 600 and 700 C then ground to 0.4 - 1 mm and applied to a sandy loam at a rate of 50 g kg-1. Bulk densities of these soil-biochar mixtures were measured on a tapped, dry, basis. The water-holding-capacity (WHC) of each mixture was measured gravimetrically following saturation and free-draining. The filter paper method was used to assess how pyrolysis temperature influences the effect of biochar application on matric suction. For all feedstocks, large decreases in biochar yield were observed between the pyrolysis temperatures of 350 C and 500 C. For Salix viminalis and M. giganteus feedstocks, subsequent reductions in the yield with increasing pyrolysis temperature were much lower. There were significant differences in hydrophobicity between biochars produced from different biomass and mean biochar hydrophobicity decreased with increasing pyrolysis temperature for all feedstocks. Results for CEC and WHC measurements will also be presented. With water contents of 0.04, 0.08 and 0.16 cm3 cm-3, the mean matric suctions of a sandy loam were higher when biochar was added. However, the differences were only statistically significant at a water content of 0.16 cm3 cm-3, where biochar produced at 500 C had the highest suction. Biochar additions always lowered the mean bulk density of a sandy loam, but there were significant differences in the extent to which biochars produced at different temperatures did this. Biochar yields and hydrophobicity vary according to feedstock type and decrease with increasing pyrolysis temperature. Application of biochar can significantly reduce bulk density but the extent of this effect varies according to the pyrolysis temperature at which the biochar is produced. Pyrolysis temperature can have a significant influence on how biochars affect soil suction. Acknowledgements: This study was funded by a UK Natural Environment Research Council (NERC) Doctoral Training Grant: NE/H525154/1.

Aston, Steve; Doerr, Stefan; Street-Perrott, Alayne

2013-04-01

135

High-temperature pyrolysis of blended animal manures for producing renewable energy and value-added biochar  

Science.gov (United States)

In this study, we used a commercial pilot-scale, skid-mounted pyrolysis reactor system to produce combustible gas and biochar at 620C from three sources (chicken litter, swine solids, mixture of swine solids with rye grass). Pyrolysis of swine solids produced gas with the greatest higher heating va...

136

High-temperature pyrolysis of blended animal manures for producing renewable energy and value-added biochar  

Science.gov (United States)

In this study, we used a commercial pilot-scale pyrolysis reactor system to produce combustible gas and biochar at 620 degrees Celsium from three sources (chicken litter, swine solids, mixture of swine solids with rye grass). Pyrolysis of swine solids produced gas with the greatest higher heating va...

137

Reproducible pyrolysis-gas chromatography of micro-organisms with solid stationary phases and isothermal oven temperatures.  

Science.gov (United States)

Eight solid stationary phases were examined for their suitability for pyrolysis-gas chromatography (Py-GC) of micro-organisms. With temperature programming these phases offered little advantage over the traditional liquid phase Carbowax 20M, but at an isothermal analysis temperature of 100 degrees C their use solved many technical problems. Pyrograms were produced containing small numbers of baseline-resolved peaks which eluted within 8 to 25 min. Four to six specimens per hour could be examined with two pyrolysers attached to one chromatograph oven. When a control organism was used to derive normalized results, pyrograms were reproducible with a second column and a second pyrolyser, suggesting that inter-laboratory reproducibility may be possible. Five different bacterial genera were well discriminated and some differentiation was achieved between different isolates of Streptococcus mutans, but similarity between pyrograms with was unrelated to orthodox taxonomic grouping. The best discrimination was achieved with Chromosorb 104, followed by Chromosorb 101 and Tenax-GC. With solid phases and isothermal oven temperatures Py-GC is a promising technique for microbial identification. PMID:7320702

French, G L; Phillips, I; Chinn, S

1981-08-01

138

The Effect of Substrate Temperature on Superconducting Properties of YBCO Films Prepared by Spray Pyrolysis Method using Metal Nitrate Precursors  

International Nuclear Information System (INIS)

YBCO films have been synthesized using a spray pyrolysis method. We used nitrates of Y, Ba, Cu as precursors. Deposition was made on LaAlO3 (100) single crystal substrate by spraying the mist of aqueous precursor solution generated by a concentric nozzle. The distance between concentric nozzle and substrate was 15 cm. C-axis oriented films were obtained at deposition temperature of 740 - 800 degrees C and working pressure of 20 Torr. Oxygen partial pressure was 3 Torr and substrate was transported with the speed ranging from 0.23 cm/min to 0.7 cm/min by reel to reel. Scanning electron microscope (SEM) and X-ray diffraction (XRD) observation revealed that films are smooth and highly textured with (001) planes parallel to substrate. Highest critical current density (Jc) was 1.38 MA/cm2 at 77K and self-field for the film with a thickness of 0.5 ?m prepared at a substrate temperature of 780 degrees C and PO2 = 3 Torr . The effect of temperature on the microstructure and YBCO phase formation will be discussed.

139

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

Energy Technology Data Exchange (ETDEWEB)

A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and show to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hyrdocarbons into hydrocarbons removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christpher P; Boldingh, Edwin P

2013-12-17

140

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

Energy Technology Data Exchange (ETDEWEB)

A new family of coherently grown composites of TUN and IMF zeotypes has been synthesized and shown to be effective catalysts for catalytic pyrolysis of biomass. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.n+R.sub.rQ.sub.qAl.sub.1-xE.sub.xSi.sub.yO.s- ub.z where M represents zinc or a metal or metals from Group 1, Group 2, Group 3 or the lanthanide series of the periodic table, R is an A,.OMEGA.-dihalosubstituted paraffin such as 1,4-dibromobutane, Q is a neutral amine containing 5 or fewer carbon atoms such as 1-methylpyrrolidine and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-39 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2014-10-07

141

Temperature dependent structural, luminescent and XPS studies of CdO:Ga thin films deposited by spray pyrolysis  

International Nuclear Information System (INIS)

Research highlights: ? The CdO:Ga thin films seems an alternative to traditional TCO materials used in photovoltaic applications. This work deals the effect of deposition temperature on sprayed CdO:Ga films with respect to the structural, luminescent and XPS studies. ? The crystalline quality of the GCO films improves with deposition temperature. ? The oxygen vacancies are responsible for n-type conductivity and green emission. ? The minimum resistivity, highest carrier concentration and mobility are 1.9 x 10-4 ? cm, 11.7 x 1021 cm-3 and 27.64 cm2 V-1 s-1, respectively. - Abstract: The structural, compositional, photoluminescent and XPS properties of CdO:Ga thin films deposited at temperatures ranging from 275 to 350 oC, using spray pyrolysis are reported. X-ray diffraction characterization of as-deposited GCO thin films reveals that films are of cubic structure with a (2 0 0) preferred orientation. The crystalline quality of the GCO films improves and the grain size increases with deposition temperature. The EDS analyses confirm oxygen deficiency present in the film and are responsible for n-type conductivity. The photoluminescence spectra demonstrated that the green emission peaks of CdO thin films are centered at 482 nm. The relative intensity of these peaks is strongly dependent on the deposition temperature. Oxygen vacancies are dominant luminescent centers for green emission inent centers for green emission in CdO thin films. The XPS measurement shows the presence of Cd, Ga, O and C elements and confirms that CdO:Ga films are cadmium-rich.

142

Effects of working temperature and carbon diffusion on the microstructure of high pressure heat-resistant stainless steel tubes used in pyrolysis furnaces during service condition  

International Nuclear Information System (INIS)

Highlights: ? Microstructure of HP tubes used in pyrolysis furnaces during service condition was studied. ? Two major phases, namely chromium and niobium carbides, existed in HP tubes in as-cast conditions. ? Temperature and carbon diffusion influence the composition and volume fraction of secondary precipitates. ? Chromium and niobium carbides were transformed to M23C6 and G-phase respectively during service. -- Abstract: In the present study, high pressure heat-resistant cast stainless steels (HP steels) modified with niobium and titanium were investigated in as-cast conditions and after being used in pyrolysis furnaces. Life span of the studied specimens obtained from pyrolysis furnace was 5 years. Microstructural changes were studied via scanning electron microscopy (SEM) equipped with energy dispersive spectrum (EDS), optical microscopy (OM), and X-ray diffraction (XRD). The effect of temperature and carbon diffusion on the microstructure, chromium-rich carbides, the NbC transformation to G-phase and other precipitates formed during service condition were discussed. The results showed that two major phases, namely chromium and niobium carbides, existed in the as-cast specimens. Temperature and carbon diffusion influenced the composition and volume fraction of secondary precipitates. Chromium and niobium carbides were transformed to M23C6 and G-phase respectively during service. Higher working temperatures do not always cause coarsening of precipitates. However, factors such as decarburization and carbon diffusion have important roles, too.

143

Application of biochar from sewage sludge to plant cultivation: Influence of pyrolysis temperature and biochar-to-soil ratio on yield and heavy metal accumulation.  

Science.gov (United States)

Applying biochar products from sewage sludge (SS) pyrolysis as soil amendment for plant cultivation was investigated in this study with special attention paid to heavy metal accumulation in the plants when pyrolysis temperature and biochar-to-soil mass ratio (C:S) were changed. Biochar obtained at four different temperatures were adopted as soil amendment for Allium sativum L. garlic plant cultivation. Experimental results revealed that biochars were rich in nutrient contents and they improved garlic yields. Although contents of heavy metals including As, Zn, Pb, Ni, Cd, Cr and Cu, etc. were elevated in the biochars compared to local soil, they fell within the acceptable limits for land application and SS is a suitable biochar resource, especially biochar produced at 450C had rich micropores, relatively stable functional groups in structure and rugged surface to contact well with soil, conducive to its usage as a biochar. The garlic grew faster when planted in the biochar-amended soil and had higher final dry matter yields than those planted in the reference soil, especially biochar produced at 450C corresponding to the highest final yields. The C:S ratio related to the highest garlic yields changed when the pyrolysis temperature was changed and this ratio was 1:4 for the biochar produced at 450C. General heavy metal accumulation in the garlic occurred only for the most enriched Zn and Cu, and mainly in the roots & bulbs; in addition this bioaccumulation was increasing as leaching from biochar increased but not increasing with C:S ratio. The garlic planted in soil amended with biochar of 450C contained the lowest level of heavy metals compared to other biochars. Those results indicated that heavy metal accumulation in plants can be inhibited through proper pyrolysis temperature choice and prevention of heavy metal leaching from the SS biochar. PMID:24582602

Song, X D; Xue, X Y; Chen, D Z; He, P J; Dai, X H

2014-08-01

144

Improved superconducting properties of MgB2 thin films fabricated by ultrasonic spray pyrolysis method at high temperature  

Science.gov (United States)

High quality MgB2 superconducting thin films have been successfully prepared by 2.4 MHz ultrasonic spray pyrolysis (USP) system on single crystal Al2O3 (0 0 1) substrates. The microstructure, electrical and magnetic properties of approximately 500-600 nm thick films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) in conjunction with the energy dispersive X-ray analysis (EDX), resistance versus temperature (R-T) and magnetization measurements (M-H) under different magnetic fields and transport critical current density (Jc). Films were first heat treated in situ in the spraying chamber with an extra Mg powder during deposition to compensate excess evaporation of Mg from the films and then additionally heat treated in Ar atmosphere at 700 C for a short time. According to the results obtained, orientation on any particular direction for the crystal growth was not seen. Homogeneous, highly dense and highly smooth surface morphology and low resistance have been achieved under optimum conditions. Optimally treated films exhibited relatively high transport critical current density of 2.37 105 A cm-2. These results have been also compared with the Jcmag results calculated from the M-H curves. The electrical resistance property of the best samples was obtained to be 39.5 and 37.4 K for Tc and Tzero, respectively.

Yakinci, M. Eyyuphan; Yakinci, Z. Deniz; Aksan, M. Ali; Balci, Yakup

2012-12-01

145

Low temperature growth of highly crystallized ZnO:Al films by ultrasonic spray pyrolysis from acetylacetone salt  

International Nuclear Information System (INIS)

High-quality ZnO:Al films were deposited on glass substrates at a relatively low temperature of 300 deg. C by ultrasonic spray pyrolysis. Zn(acac)2 and Al(acac)3 acted as zinc and aluminum source, which dissolved in ethanol-water solution. The influences of aluminum concentration and vacuum annealing on microstructure, electrical and optical properties were investigated by XRD, SEM, EDS, four-point probe and visible spectroscopy. The experimental results shown that ZnO:Al films exhibit stronger (1 0 1) preferred orientation and have lenticular-like grain morphology. The resistivity as low as 4.3 x 10-1 ? cm for as-deposited films was obtained at the 4 at.% doping concentration, which can be decreased to 10-2 ? cm level by post-deposited vacuum annealing. The average transmittance of as-deposited films was nearly 80% in the visible range, and that of 4 at.% doped ZnO films reduced to 60% after vacuum annealing at 550-600 deg. C.

146

Refine pyrolysis tested at Goldshoefe  

Energy Technology Data Exchange (ETDEWEB)

Low temperature refuse pyrolysis provides a way of disposing of various types of waste and generating power while avoiding problems with organic pollutants and toxic metals. Kraftwert Union have been testing the concept in a pilot plant in Goldshoefe, FRG.

Berwein, H.-J.; Aurin, G.

1987-02-01

147

GLC analysis of temperature effects on furfural production during pyrolysis of black cherry  

Energy Technology Data Exchange (ETDEWEB)

Thermal degradation of black cherry (Prunus serotina Ehrh.) was conducted in an inert atmosphere at temperatures ranging from 250/sup 0/ to 1000/sup 0/C. The volatiles produced during carbonization were condensed in a liquid nitrogen trap and separated by steam distillation after which they were extracted with ether. This fraction was analyzed by gas-liquid chromatography (GLC) using a 4-mm (inside diameter) by 1.83-m-long glass column packed with 10 percent methyl silicone fluid. The GLC column temperature was programed from 40/sup 0/ to 240/sup 0/C at a rate of 12.5/sup 0/C per minute. Using this GLC temperature program, three chromatograms from each carbonization temperature were obtained and the furfural peak was identified and quantitatively analyzed. As carbonization temperature increased from 250/sup 0/ to 500/sup 0/C, the amount of furfural in the condensate also increased. The condensate chromatograms show that considerably more compounds are formed at temperatures above 320/sup 0/C than at 250/sup 0/C. The chromatograms from the temperature range of 500/sup 0/ to 1000/sup 0/C showed little change in the number of compounds detected. Regression analysis revealed relationships between carbonization temperature, mass of the condensate, and mass of furfural per original mass of wood.

Barnes, D.P.; Blankenhorn, P.R.; Murphey, W.K.

1979-10-01

148

GLC analysis of temperature effects on furfural production during pyrolysis of black cherry  

Energy Technology Data Exchange (ETDEWEB)

Thermal degradation of black cherry (Prunus serotina Ehrh.) was conducted in an inert atmosphere at temperatures ranging from 250/sup 0/ to 1000/sup 0/C. The volatiles produced during carbonization were condensed in a liquid nitrogen trap and separated by steam distillation after which they were extracted with ether. This fraction was analyzed by gas-liquid chromatography (GLC) using a 4-mm (inside diameter) by 1.83-m-long glass column packed with 10 percent methyl silicone fluid. The GLC column temperature was programed from 40/sup 0/ to 240/sup 0/C at a rate of 12.5/sup 0/C per minute. Using this GLC temperature program, three chromatograms from each carbonization temperature were obtained and the furfural peak was identified and quantitatively analyzed. As carbonization temperature increased from 250/sup 0/ to 500/sup 0/C, the amount of furfural in the condensate also increased. The condensate chromatograms show that considerably more compounds are formed at temperatures above 320/sup 0/C than at 250/sup 0/C. The chromatograms from the temperature range of 500/sup 0/ to 1000/sup 0/C showed little change in the number of compounds detected. Regression analysis revealed relationships between carbonization temperature, mass of the condensate, and mass of furfural per original mass of wood. 3 figures, 4 tables.

Barnes, D.P.; Blankenhorn, P.R.; Murphey, W.K.

1979-10-01

149

GlC analysis of temperature effects on furfural production during pyrolysis of black cherry  

Energy Technology Data Exchange (ETDEWEB)

Thermal degradation of black cherry (Prunus serotina Ehrh.) was conducted in an inert atmosphere at temperatures ranging from 250 degrees to l000 degrees Celcius. The volatiles produced during carbonization were condensed in a liquid nitrogen trap and separated by steam distillation after which they were extracted with ether. This fraction was analyzed by gas-liquid chromatography (GLC) using a 4 mm (inside diameter) by 1.83 m long glass column packed with l0 percent methyl silicone fluid. The (GLC) column temperature was programed from 40 degrees to 240 degrees at a rate of l2.5 degrees Celcius per minute. Using this GLC temperature program, three chromatograms from each carbonization temperature were obtained and the furfural peak was identified and quantitatively analyzed. As carbonization temperature increased from 250 degrees at 500 degrees Celcius, the amount of furfural in the condensate also increased. The condensate chromatograms show that considerably more compounds are formed at temperatures above 320 degrees Celcius. The chromatograms from the temperature range of 500 degrees to l000 degrees showed little change in the number of compounds detected. Regression analysis revealed relationships between carbonization temperature, mass of the condensate, and mass furfural per original mass of wood.

Barnes D.P.; Blankenhorn, P.R.; Murphey, W.K.

1979-10-01

150

Flash pyrolysis at high temperature of ligno-cellulosic biomass and its components - production of synthesis gas; Pyrolyse flash a haute temperature de la biomasse ligno-cellulosique et de ses composes - production de gaz de synthese  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis is the first stage of any thermal treatment of biomass and governs the formation of synthesis gas for the production of electricity, hydrogen or liquid fuels. The objective of this work is to establish a link between the composition of a biomass and its pyrolysis gas. We study experimental flash pyrolysis and fix the conditions in which quantities of gas are maximal, while aiming at a regime without heat and mass transfer limitations (particles about 100 {mu}m): temperature of 950 C and residence time of about 2 s. Then we try to predict gas yields of any biomass according to its composition, applicable in this situation where thermodynamic equilibrium is not reached. We show that an additivity law does not allow correlating gas yields of a biomass with fractions of cellulose, hemi-cellulose and lignin contained in this biomass. Several explanations are suggested and examined: difference of pyrolytic behaviour of the same compound according to the biomass from which it is extracted, interactions between compounds and influence of mineral matter. With the aim of industrial application, we study pyrolysis of millimetric and centimetric size particles, and make a numerical simulation of the reactions of pyrolysis gases reforming. This simulation shows that the choice of biomass affects the quantities of synthesis gas obtained. (author)

Couhert, C

2007-11-15

151

High-Temperature Jet Spray Reactor for the Preparation of Rare Earth Oxides by Pyrolysis: Computer Simulation  

Science.gov (United States)

A new type of high-temperature jet spray pyrolysis (SP) reactor is investigated in this article as part of studies on the preparation of rare earth oxides at Northeastern University (NEU), Shenyang, China. The jet spray reactor examined here is a horizontal, tubular reactor conveying the hot products of the combustion of methane and oxygen with a converging-diverging jet section in an arrangement that provides for inspiration of LaCl3 solution to pyrolyze to La2O3 with the hot gas. The present article is concerned with a computer simulation using a computational fluid dynamic model to develop the velocity, temperature, and pressure profiles in the jet reactor since direct measurement is difficult. The article includes brief comments on a room-temperature model designed to examine the flow characteristics of the jet SP reactor. It was found that the velocity decreased at first, and then it increased near the jet throat. The highest velocity occurred at the throat of jet SP reactor where the LaCl3 enters the unit. Along the reactor axis, the temperature decreases with distance from the gas inlet. The lowest temperature zone was near the wall before the throat of the reactor due to wall heat losses. The temperature was estimated to be close to 1700 K at the throat of the reactor, and it was about 1300 K toward the exit of the reactor. It was shown that a reaction would take place mainly in the throat and in the vicinity of first contact between gas and induced spray. A negative pressure was produced as gas passes through the converging-diverging throat of the jet SP reactor that causes the LaCl3 solution to enter the throat of the reactor. While the investigations of this type of reactor are at an early stage, the results look promising. NEU continues to investigate this approach for the preparation of La2O3 based on high-temperature testwork and physical modeling techniques.

Zhao, Qiu-yue; Lv, Chao; Zhang, Zi-mu; Dou, Zhi-he; Zhang, Ting-an; Liu, Yan; Lv, Guo-zhi

2014-09-01

152

Conventional and fast pyrolysis of automobile shredder residues (ASR).  

Science.gov (United States)

This work aims at comparing performance and product yields in conventional pyrolysis and fast pyrolysis of automotive shredded residues. In both processes, carbon conversion to gaseous and liquid products was more than 80%. Gas production was maximised in conventional pyrolysis (about 35% by weight of the initial ASR weight), while fast pyrolysis led to an oil yield higher than 55%. Higher heating values (HHV) of both conventional pyrolysis gas and fast pyrolysis oil increased from 8.8 to 25.07 MJ/Nm3 and from 28.8 and 36.27 MJ/kg with increasing pyrolysis temperature. PMID:15288301

Zolezzi, Marcello; Nicolella, Cristiano; Ferrara, Sebastiano; Iacobucci, Cesare; Rovatti, Mauro

2004-01-01

153

Catalytic pyrolysis of polyethylene  

Energy Technology Data Exchange (ETDEWEB)

The influence of zeolite catalytic upgrading of the pyrolysis gases derived from the pyrolysis of polyethylene has been investigated. The yield and composition of the derived hydrocarbon gases and oils have been investigated in terms of the temperature of the catalyst. Polyethylene was pyrolysed in a fixed bed reactor and the pyrolysis gases passed to a secondary reactor containing Y-zeolite or zeolite ZSM-5 catalyst. The polyethylene was pyrolysed at 500C and the temperature of the catalyst bed was 400, 450, 500, 550 or 600C. The oils consisted of mainly aliphatic compounds represented by alkadiene, alkene and alkane hydrocarbons and their branched chain derivatives. The uncatalysed pyrolysis oil also contained low concentrations of aromatic hydrocarbons. After catalysis there was a marked increase in the concentration of aromatic compounds in the oil, which further increased in concentration as the temperature of catalysis was raised. The single ring compounds consisted of mainly toluene, ethylbenzene and xylenes and the two and three ring compounds were mainly, naphthalene and phenanthrene and their methyl derivatives. The Y-zeolite produced significantly greater concentration of aromatic hydrocarbons in the derived oils compared to when zeolite ZSM-5 catalyst was used.

Bagri, Ranbir; Williams, Paul T. [Department of Fuel and Energy, The University of Leeds, LS2 9JT Leeds (United Kingdom)

2002-03-01

154

Temperature-dependent benzoic acid elimination mechanisms in pyrolysis of (-)-cocaine  

Scientific Electronic Library Online (English)

Full Text Available The thermal elimination of benzoic acid from (-)-cocaine is shown to be temperature-dependent. In the temperature range of 200-500 C only a trans-elimination is observed leading to methylecgonidine. Above ca. 500 C a second mechanism, the cis-elimination, comes up yielding a novel alkaloid methyli [...] soecgonidine which has been characterized by means of mass spectrometry. At 600 C the cis-elimination predominates. The trans-elimination is postulated a two-step process consisting of a 1,7- and a 1,5-hydrogen shift. The chemistry of cocaine base smoking is explained using the theory of chemical activation.

Michal, Novk.

155

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

Energy Technology Data Exchange (ETDEWEB)

A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula Na.sub.nM.sub.m.sup.k+T.sub.tAl.sub.1-xE.sub.xSi.sub.yO.sub.z where "n" is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, "m" is the mole ratio of M to (Al+E), "k" is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-44 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2013-12-17

156

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

Science.gov (United States)

A new family of aluminosilicate zeolites designated UZM-44 has been synthesized. These zeolites are represented by the empirical formula. Na.sub.nM.sub.m.sup.k+T.sub.tAl.sub.1-xE.sub.xSi.sub.yO.sub.z where "n" is the mole ratio of Na to (Al+E), M represents a metal or metals from zinc, Group 1, Group 2, Group 3 and or the lanthanide series of the periodic table, "m" is the mole ratio of M to (Al+E), "k" is the average charge of the metal or metals M, T is the organic structure directing agent or agents, and E is a framework element such as gallium. The process involves contacting a carbonaceous biomass feedstock with UZM-44 at pyrolysis conditions to produce pyrolysis gases comprising hydrocarbons. The catalyst catalyzes a deoxygenation reaction converting oxygenated hydrocarbons into hydrocarbons and removing the oxygen as carbon oxides and water. A portion of the pyrolysis gases is condensed to produce low oxygen biomass-derived pyrolysis oil.

Nicholas, Christopher P; Boldingh, Edwin P

2014-04-29

157

Influence of deposition temperature (T {sub s}), air flow rate (f) and precursors on cathodoluminescence properties of ZnO thin films prepared by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Semiconducting metal oxide such as ZnO films were prepared by the spray pyrolysis technique on glass substrates. The cathodoluminescence properties of these films were investigated with respect to deposition temperature (T {sub s}) and air flow rate (f). The luminescent films had a polycrystalline hexagonal wurtzite-type structure. Cathodoluminescence intensity was critically dependent on substrate temperature and spray rate. The best films had three emissions: near ultra-violet (UV) band gap peak at 382 nm, a blue-green emission at 520 nm and a red emission at 672 nm. These films were deposited at optimum condition: T {sub s}=450 deg C and f=5 ml/min.

El Hichou, A. [Laboratoire de Microscopies et d' Etude des Nanostructures, Universite de Reims, UFR Sciences exactes, LMEN, Equipe d' Accueil No. 3799, B.P. 138, 21 rue Clement Ader, 51685 Reims cedex2 (France) and Departement de physique, Faculte des Sciences et Techniques Gueliz, Universite Cadi Ayyad, B.P. 549 Marrakech, Marocco (Morocco)]. E-mail: elhichou@fstg-marrakech.ac.ma; Addou, M. [Lab. d' Optoelectronique et de Physico-Chimie des materiaux, Faculte des Sciences, Universite Ibn Tofail, B.P. 133, Kenitra, Marocco (Morocco); Ebothe, J. [Laboratoire de Microscopies et d' Etude des Nanostructures, Universite de Reims, UFR Sciences exactes, LMEN, Equipe d' Accueil No. 3799, B.P. 138, 21 rue Clement Ader, 51685 Reims cedex2 (France); Troyon, M. [Laboratoire de Microscopies et d' Etude des Nanostructures, Universite de Reims, UFR Sciences exactes, LMEN, Equipe d' Accueil No. 3799, B.P. 138, 21 rue Clement Ader, 51685 Reims cedex2 (France)

2005-06-15

158

Influence of deposition temperature (T s), air flow rate (f) and precursors on cathodoluminescence properties of ZnO thin films prepared by spray pyrolysis  

International Nuclear Information System (INIS)

Semiconducting metal oxide such as ZnO films were prepared by the spray pyrolysis technique on glass substrates. The cathodoluminescence properties of these films were investigated with respect to deposition temperature (T s) and air flow rate (f). The luminescent films had a polycrystalline hexagonal wurtzite-type structure. Cathodoluminescence intensity was critically dependent on substrate temperature and spray rate. The best films had three emissions: near ultra-violet (UV) band gap peak at 382 nm, a blue-green emission at 520 nm and a red emission at 672 nm. These films were deposited at optimum condition: T s=450 deg C and f=5 ml/min

159

Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal  

Energy Technology Data Exchange (ETDEWEB)

Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500/sup 0/C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by n.m.r., and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars.

Furimsky, E.; Ciavaglia, L.A.; MacPhee, J.A.; Nandi, B.N.; Vancea, L.

1983-04-01

160

Effect of oxidation on the chemical nature and distribution of low-temperature pyrolysis products from bituminous coal  

Energy Technology Data Exchange (ETDEWEB)

Two bituminous coals, a high volatile Eastern Canadian and a medium volatile Western Canadian, were used to investigate the effect of oxidation on yields and chemical composition of gases, liquids and chars produced during coal pyrolysis. Pyrolysis experiments were performed at 500 C using the Fischer assay method. Mild oxidation of coals resulted in a decrease of liquid hydrocarbon yields. Further coal oxidation increased the proportion of aromatic carbon in liquid products as determined by N.M.R. and also increased the content of oxygen in liquid products. The content of oxygen in chars was markedly lower than in corresponding coals. An attempt is made to explain reactions occurring during oxidation and subsequent pyrolysis of coal on the basis of differences in chemical composition of gases, liquids and chars. (19 refs.)

Furimsky, E.; MacPhee, J.A.; Vancea, L.; Ciavaglia, L.A.; Nandi, B.N.

1983-04-01

161

Copyrolysis of Seyitomer-lignite and safflower seed: influence of the blending ratio and pyrolysis temperature on product yields and oil characterization  

Energy Technology Data Exchange (ETDEWEB)

Pyrolytic behaviors of biomass/coal mixtures were investigated under a heating rate of 7{sup o}C min{sup -1}, over a range of pyrolysis temperatures between 400 and 700{sup o}C, and the blending ratio of coal in mixtures was varied between 0 and 100 wt %. The results indicated that considerable synergistic effects were observed during the copyrolysis in a fixed-bed reactor leading to an increase in the oil yield at lower than coal blending ratios of 33%. At the lower blending coal ratio conditions, the oil yields are higher than the expected ones, calculated as the sum of oil fractions produced by pyrolysis of each separated component. The maximum pyrolysis oil yield of 39.5% was obtained with 5% of lignite mixed with safflower seed. The obtained oils are characterized by Fourier transform infrared spectroscopy, {sup 1}H nuclear magnetic resonance, gas chromatography mass spectrometry, and elemental analysis. These findings can potentially help to understand and predict the behavior of coal/biomass blends in practical liquefaction systems. 33 refs., 8 figs., 4 tabs.

Ozlem Onay; Evren Bayram; O. Mete Kockar [Anadolu University, Eskisehir (Turkey). Porsuk Vocational School

2007-09-15

162

Effect of low-temperature oxidation on the pyrolysis and combustion of whole oil  

International Nuclear Information System (INIS)

Low-temperature oxidation (LTO) of the Fosterton crude oil mixed with its reservoir sand has been investigated in a tubular reactor. Reservoir sand saturated with 15 wt% of crude oil (20.5o API gravity) was subjected to air injection at low-temperature (220 oC) for a period of time (17 h and 30 min), resulting in the formation of an oxygenated hydrocarbon fuel. The vent gases were analyzed for the content of CO, CO2, and oxygen and the residue was analyzed to determine the elemental composition and calorific value. The presence of LTO region was verified from the values of apparent H/C ratio. In addition, thermal behavior and combustion kinetics of the residue was investigated using thermogravimetric analysis (TGA). TG involves both non-isothermal and isothermal analysis and kinetic data was derived from isothermal studies. The general model for nth order reaction was used to obtain the kinetic parameters of the coke oxidation reaction. The activation energy, frequency factor and order of the reactions were determined using the model.

163

Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique  

International Nuclear Information System (INIS)

Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO3 (H2O)2 was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into ?-MoO3. The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO3 films' sensitivity was analyzed for CO and H2O in the temperature range 160 to 360 K; the results indicate that CO and H2O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H2O. - Highlights: ? A low cost technique is used which produces good material. ? Thin films are prepared using ammonium molybdate tetra hydrated. ? The control of the physical properties of the samples could be done. ? A calculation method is proposed to determine the material optical properties. ? The MoO3 thin films prepared by spray pyrolysis could be used as gas syrolysis could be used as gas sensor.

164

Decrease of bulk pinning strength in deoxygenated YBCO single crystals  

International Nuclear Information System (INIS)

We measured the first and third harmonics of the complex AC susceptibility in YBCO single crystals with different oxygen contents (6.5 ? x ? 7). The amplitude of the AC field was varied in presence of an external dc field both applied parallel to the c-axis of the crystals. We give evidence that deoxygenation leads to a reduction of the bulk pinning strength and consequently to a stronger contribution of geometrical barriers. These results support the recently reported investigations showing that deoxygenation makes the YBCO crystals more anisotropic reducing the effective bulk pinning for quasi two-dimensional vortices. We also show measurements for the same crystals with the AC field applied perpendicular to the c-axis. (orig.)

165

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs.

Chun, Ung Kyung [Korea Electric Power Research Insititute, Taejon (Korea, Republic of)

1997-12-31

166

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin  

International Nuclear Information System (INIS)

Pyrolysis may be an important pretreatment step before vitrification in a cold crucible melter (CCM). During vitrification of organic resin the carbon or other remaining residues may harm the performance of the cold crucible melter of the eventual stability of the final glass product. Hence, it is important to reduce or prevent such harmful waste from entry into the cold crucible melter. Pretreatment with pyrolysis will generally provide volume reduction resulting in less amount of solid waste that needs to be handled by the CCM; in addition, the pyrolytic processes may breakdown much of the complex organics causing release through volatilization resulting in less carbon and other harmful substances. Hence, KEPRI has undertaken studies on the pyrolysis and oxidative pyrolysis of organic ion exchange resin. Pyrolysis and oxidative pyrolysis were examined with TGA and a tube furnace. TGA results for pyrolysis with the flow of nitrogen indicate that even after pyrolyzing from room temperature to about 900 deg C, a significant mass fraction of the original cationic resin remains, approximately 46 %. The anionic resin when pyrolytically heated in a flow of nitrogen only, from room temperature to about 900 deg C, produced a final residue mass fraction of about 8 percent. Oxidation at a ratio of air to nitrogen, 1:2, reduced the cationic resin to 5.3% when heated at 5 C/min. Oxidation of anionic resin at the same ratio and same heating rate left almost no solid residue. Pyrolysis (e.g. nitrogen-only environment) in the tube furnace of larger samples relative to the TGA produced very similar results to the TGA. The differences may be attributed to the scale effects such as surface area exposure to the gas stream, temperature distributions throughout the resin, etc. (author) 7 refs., 7 figs

167

Biochar carbon stability in a clayey soil as a function of feedstock and pyrolysis temperature.  

Science.gov (United States)

The stability of biochar carbon (C) is the major determinant of its value for long-term C sequestration in soil. A long-term (5 year) laboratory experiment was conducted under controlled conditions using 11 biochars made from five C3 biomass feedstocks (Eucalyptus saligna wood and leaves, papermill sludge, poultry litter, cow manure) at 400 and/or 550 C. The biochars were incubated in a vertisol containing organic C from a predominantly C4-vegetation source, and total CO(2)-C and associated ?(13)C were periodically measured. Between 0.5% and 8.9% of the biochar C was mineralized over 5 years. The C in manure-based biochars mineralized faster than that in plant-based biochars, and C in 400 C biochars mineralized faster than that in corresponding 550 C biochars. The estimated mean residence time (MRT) of C in biochars varied between 90 and 1600 years. These are conservative estimates because they represent MRT of relatively labile and intermediate-stability biochar C components. Furthermore, biochar C MRT is likely to be higher under field conditions of lower moisture, lower temperatures or nutrient availability constraints. Strong relationships of biochar C stability with the initial proportion of nonaromatic C and degree of aromatic C condensation in biochar support the use of these properties to predict biochar C stability in soil. PMID:23013285

Singh, Bhupinder Pal; Cowie, Annette L; Smernik, Ronald J

2012-11-01

168

Kinetics of Increased Deformability of Deoxygenated Sickle Cells upon Oxygenation  

Science.gov (United States)

We have examined the kinetics of changes in the deformability of deoxygenated sickle red blood cells when they are exposed to oxygen (O2) or carbon monoxide. A flow-channel laser diffraction technique, similar to ektacytometry, was used to assess sickle cell deformability after mixing deoxygenated cells with buffer that was partially or fully saturated with either O2 or carbon monoxide. We found that the deformability of deoxygenated sickle cells did not regain its optimal value for several seconds after mixing. Among density-fractionated cells, the deformability of the densest fraction was poor and didn't change as a function of O2 pressure. The deformability of cells from the light and middle fraction increased when exposed to O2 but only reached maximum deformability when equilibrated with supraphysiological O2 concentrations. Cells from the middle and lightest fraction took several seconds to regain maximum deformability. These data imply that persistence of sickle cell hemoglobin polymers during circulation in vivo is likely, due to slow and incomplete polymer melting, contributing to the pathophysiology of sickle cell disease. PMID:14507701

Huang, Zhi; Hearne, Leigh; Irby, Cynthia E.; King, S. Bruce; Ballas, Samir K.; Kim-Shapiro, Daniel B.

2003-01-01

169

Catalytic pyrolysis of biomass in a fluidized bed reactor  

Energy Technology Data Exchange (ETDEWEB)

Liquid, solid and gaseous fuels or fuel precursors can be produced from biomass through pyrolysis, which in essence is the thermal degradation of an organis material. The fuels can be used as such in stationary power plants. Upgrading of the liquid bio-oil is required for application in mobile diesel or gasoline engines. besides the use as a fuel, valuable chemicals can be extracted from the bio-oil. The thesis focuses on the upgrading of biomass derived pyrolysis vapours over various zeolite catalysis in fluidized bed reactors. Fluidized bed reactors were designed and constructed for the catalytic pyrolysis experiments. The first reactor set-up applied zeolites as a bed material in the pyrolysis reactor. In this way, the heat for the pyrolysis reactions was obtained by the preheated zeolites, simultaneously upgrading of the pyrolysis vapoursoccurred. The operation and screening of catalyst in the first reactor set-up was challenging. Therefore, a new dual-fluidized bed reactor was designed, where the two reactors, easier operation of the pyrolysis and catalytic reactor coud be established. De-oxygenation reactions of pine wood pyrolysis vapours over diverse zeolites, which are microporoous crystalline aluminosilicates, with differnt structures and acidities used in the presence of a binder and optinally functionalized with metals, were carried out in the present work. The zeolite structures of beta, Y, ZSM-5, ferrierite and mordenite were tested. Different acidities of the beta zeolite, having silica to alumina ratios of 25, 150 and 300, were also applied in the experiments. The effect of bentonite as a binder was tested for beta and ZSM-5 structure. Iron modification through ion-exchage was performed on beta, Y and ferrierite materials, which were further tested as catalysts in the pyrolysis of biomass. Besides testing different catalysts, conventional thermal pyrolysis of various biomass and model compounds was investigated. Pine wood, two types of beet pulp, cellulose and the hemicellulose galactoglucomannan were used as raw materials. The chemical composition of the bio-oil is affected to a great extent by the choice of raw material. The pine wood bio-oils had a large number of different phenolics, originating from the lignin polymer. Otherwise, the bio-oils from the different raw materials had a large number of different oxygenated organics such as furan derivatives, but also non-cyclic molecules like acetic acid and hydroxyacetone. De-oxygenation over zeolites was confirmed by an increased water formation and higher CO to CO{sub 2} ratios. The spent zeolites could be regenerated by burning away the formed coke, and the surface area and aciduty of the zeolites were regained. (orig.)

Aho, A.

2009-07-01

170

Effect of substrate temperature on electrical, structural, optical and cathodoluminescent properties of In2O3-Sn thin films prepared by spray pyrolysis  

International Nuclear Information System (INIS)

Tin doped indium oxide thin films In2O3-Sn, have been deposited on glass substrate at various temperatures (723, 748 and 773 K), using spray pyrolysis techniques. The optimal substrate temperature to obtain films of high crystallographic quality was 773 K. For this temperature, the electrical resistivity is in the order of 3x10-4 ? cm and the average optical transmission in the visible region is larger than 95%. The films were polycrystalline, crystallize in a cubic structure of the bixbyite Mn2O3 (I) type, and are preferentially orientated along the (400) direction. The cathodoluminescence spectra of In2O3-Sn thin films taken at room temperature, present two emission peaks, the first one at 410 nm corresponding to indirect band gap emission and the second one at 650 nm is related to oxygen deficiencies acting as defects

171

Preparation of fluorine-doped tin oxide films at low substrate temperature by an advanced spray pyrolysis technique, and their characterization  

International Nuclear Information System (INIS)

Indispensable fluorine-doped tin oxide thin films were prepared on glass substrates by an advanced spray pyrolysis technique at low substrate temperature, with stannic chloride (SnCl4.5H2O) and ammonium fluoride (NH4F) as precursors. The films were grown at different substrate temperatures varied in the range of 523613 K. The influence of the substrate temperature on the structural, morphological, optical and electrical properties of the films has been investigated. XRD studies show that all the films are polycrystalline and have a tetragonal crystal structure. The films deposited at the 613 K substrate temperature exhibit the lowest sheet resistance (17.82 ?) with optical transmittance of ?75% (at 550 nm). Hall-effect measurements showed that the films are heavily doped degenerate semiconductors with n-type electrical conductivity

172

Hydrous pyrolysis of pole treating chemicals: (a) initital measurement of hydrous pyrolysis rates for napthalene and pentachlorophenol; (b) solubility of flourene at temperatures up to 150{degrees}C  

Energy Technology Data Exchange (ETDEWEB)

The temperature dependencies of the hydrous pyrolysis/oxidation (HPO) aqueous phase oxidation reactions of naphthalene and pentachlorophenol have been determined for phosphate buffered systems using Dickson-type reaction vessels. The HPO experimental temperatures ranged from 114{degrees}C to 148{degrees}C for naphthalene and 114{degrees}C to 137{degrees}C for pentachlorophenol. The loss of the organic species was used to determine activation energies of 95.8 kJ/mole for naphthalene oxidation and 84.8 kJ/mole for pentachlorophenol oxidation. Aqueous concentrations of target compounds and reaction intermediates were determined by gas chromatography and compound identification was verified by gas chromatography - mass spectrometry. During the experiments the pollutants were completely mineralized, as indicated by a stoichiometric production of inorganic carbon in the case of naphthalene and inorganic carbon and chloride in the case of pentachlorophenol. HPO of pentachlorophenol produced 2,3,5,6- tetrachlorophenol as an intermediate, whereas no intermediates amenable by GC were observed during the HPO of naphthalene. Measurements of the aqueous solubility of florin in an unbuffered solution have been made covering the temperature range from 20{degrees}C to 150{degrees}C. There is very good agreement between this data set and data previously published covering the lower temperature range (20{degrees}C to 75{degrees}C). Extension of the solubility measurements to higher temperatures covers the in situ temperatures achievable during field application of HPO and demonstrated a nearly exponential rise in aqueous solubility as a function of temperature, with a 10 fold increase in aqueous florin solubility going from 75{degrees}C to 125{degrees}C and a 20 fold increase in going from 75{degrees}C to 150{degrees}C.

Leif, R. N., LLNL

1997-11-15

173

Pyrolsis of waste paper: characterization and composition of pyrolysis oil  

Energy Technology Data Exchange (ETDEWEB)

This article presents the results of an experimental study of waste paper pyrolysis in tubular furnace pyrolysis equipment. Pyrolysis of waste paper has been conducted in different pyrolysis temperatures and heating rates to investigate the product distribution and yields of pyrolysis products. The pyrolysis oil was characterized by elemental analysis and various chromatographic and spectroscopic techniques, which are HPLC, 1 H NMR, FTIR, and UV. The results of spectroscopic and chromatographic analysis show that there are four main different compounds in bio-oil: anhydrosugars, carboxyl compounds, carbonyl compounds and aromatic compounds. (Author)

Li, Lin; Zhang, Hongxun; Zhuang, Xuliang [Chinese Academy of Science, Beijing (China). Lab. of Environmental Biotechnology

2005-07-15

174

Structural and optical properties of nanostructural V2O5 thin films deposited by spray pyrolysis technique: Effect of the substrate temperature  

International Nuclear Information System (INIS)

V2O5 thin films were deposited on glass substrates by spray pyrolysis technique. The variation in the structural and optical properties with a variation in the substrate temperature was investigated by means of X-ray diffraction (XRD) and UVvis spectrophotometer. XRD was used to reveal the possible orientations of crystallites in the films prepared at different substrate temperatures ranging from 200 C to 550 C. The results showed that by increasing the temperature, the films grew along the (001) direction with an orthorhombic structure. The crystallite size was calculated using the Scherrer equation and observed that it increased with elevating the substrate temperature to 450 C, but decreased when further increasing it. The highest transmittance was achieved when films were deposited at 550 C. The absorption edge was estimated by using the Tauc plot. In the range 350 C550 C, a shift of the absorption edge from 2.5 eV to 2.8 eV was observed due to the formation of chemical bonds at the V2O5 filmsubstrate interface at high substrate temperatures (>450 C). Field emission scanning electron microscopy showed that nanorods were formed when depositing at 500 C. We conclude that by altering the substrate temperature the size of crystallites can be well controlled. - Highlights: ? Spray pyrolysis technique was used. ? We have synthesized highly oriented nanocrystalline V2O5 films. ? By altering the substrate temperature the size of crystallites can be well controlled. ? The highest transmittance was achieved when films were deposited at 550 C. ? Scanning electron microscopy showed that nanorods were formed when depositing at 500 C

175

The development of the method of low-temperature peat pyrolysis on the basis of alumosilicate catalytic system  

Energy Technology Data Exchange (ETDEWEB)

The catalytic pyrolysis of peat was investigated over several iron-containing zeolites of different structure (Beta, Y, Mordenite, ZSM-5) and SiO{sub 2}/Al{sub 2}O{sub 3} molar ratios at 410{sup o}C in a batch mode. The overall activity of iron-containing catalysts was similar, being however significantly higher than activity of parent materials. Additionally, iron-modified zeolites afforded higher ethene and propene selectivity than corresponding proton forms.

E.M. Sulman; V.V. Alferov; Y.Y. Kosivtsov; A.I. Sidorov; O.S. Misnikov; A.E. Afanasiev; N. Kumar; D. Kubicka; J. Agullo; T. Salmi; D.Y. Murzin [Tver State University, Tver (Russian Federation)

2007-11-01

176

Influence of pyrolysis temperature on fracture response in SiOC based composites reinforced by basalt woven fabric.  

Czech Academy of Sciences Publication Activity Database

Ro?. 34, ?. 14 (2014), s. 3389-3398. ISSN 0955-2219 R&D Projects: GA ?R GAP107/12/2445; GA Mk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 ; RVO:67985891 ; RVO:61389013 Keywords : Fracture behaviour * CMCs * Pyrolysis * Basalt fibre * Polysiloxane Subject RIV: JL - Materials Fatigue, Friction Mechanics; JI - Composite Materials (USMH-B); JH - Ceramics, Fire-Resistant Materials and Glass (UMCH-V) Impact factor: 2.307, year: 2013

Chlup, Zden?k; ?ern, Martin; Strachota, Adam; Sucharda, Zbyn?k; Halasov, Martina; Dlouh, Ivo

2014-01-01

177

Kinetic investigation of wood pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The objective of this investigation was to determine the kinetics of the primary reactions of wood pyrolysis. A new experimental method was developed which enabled us to measure the rate of gas, tar, and char production while taking into account the temperature variations during the wood heating up. The experimental method developed did not require any sophisticated instruments. It facilitated the collection of gas, tar and residue (unreacted wood and char) as well as accurate measurement of the temperature inside the wood sample. Expressions relating the kinetic parameters to the measured variables were derived. The pyrolysis kinetics was investigated in the range of 300 to 400/sup 0/C at atmospheric pressure and under nitrogen atmosphere. Reaction temperature and mass fractions of gas, tar, and residue were measured as a function of time. Assuming first-order reactions, the kinetic parameters were determined using differential method. The measured activation energies of wood pyrolysis to gas, tar, and char were 88.6, 112.7, and 106.5 kJ/mole, respectively. These kinetic data were then used to predict the yield of the various pyrolysis products. It was found that the best prediction was obtained when an integral-mean temperature obtained from the temperature-time curve was used as reaction temperature. The pyrolysis products were analyzed to investigate the influence of the pyrolysis conditions on the composition. The gas consisted mainly of carbon dioxide, carbon monoxide, oxygen, and C/sub 3//sup +/-compounds. The gas composition depended on reaction time as well as reactor temperature. The tar analysis indicated that the tar consisted of about seven compounds. Its major compound was believed to be levoglucosan. Elemental analysis for the char showed that the carbon content increased with increasing temperature.

Thurner, F.; Mann, U.; Beck, S. R.

1980-06-01

178

Pyrolysis process for producing fuel gas  

Science.gov (United States)

Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

2007-01-01

179

Pyrolysis processing for solid waste resource recovery  

Science.gov (United States)

Solid waste resource recovery in space is effected by pyrolysis processing, to produce light gases as the main products (CH.sub.4, H.sub.2, CO.sub.2, CO, H.sub.2O, NH.sub.3) and a reactive carbon-rich char as the main byproduct. Significant amounts of liquid products are formed under less severe pyrolysis conditions, and are cracked almost completely to gases as the temperature is raised. A primary pyrolysis model for the composite mixture is based on an existing model for whole biomass materials, and an artificial neural network models the changes in gas composition with the severity of pyrolysis conditions.

Serio, Michael A. (Inventor); Kroo, Erik (Inventor); Wojtowicz, Marek A. (Inventor); Suuberg, Eric M. (Inventor)

2007-01-01

180

A two-dimensional hybrid with molybdenum disulfide nanocrystals strongly coupled on nitrogen-enriched graphene via mild temperature pyrolysis for high performance lithium storage  

Science.gov (United States)

A novel 2D hybrid with MoS2 nanocrystals strongly coupled on nitrogen-enriched graphene (MoS2/NGg-C3N4) is realized by mild temperature pyrolysis (550 C) of a self-assembled precursor (MoS3/g-C3N4-H+/GO). With rich active sites, the boosted electronic conductivity and the coupled structure, MoS2/NGg-C3N4 achieves superior lithium storage performance.A novel 2D hybrid with MoS2 nanocrystals strongly coupled on nitrogen-enriched graphene (MoS2/NGg-C3N4) is realized by mild temperature pyrolysis (550 C) of a self-assembled precursor (MoS3/g-C3N4-H+/GO). With rich active sites, the boosted electronic conductivity and the coupled structure, MoS2/NGg-C3N4 achieves superior lithium storage performance. Electronic supplementary information (ESI) available: Photo images, Zeta potential, additional SEM, TEM, HRTEM and AFM images, XRD, FTIR, TGA under N2, TGA under air, pore size distribution, additional XPS are presented. N doping conditions, cycling/rate performances are listed in tables. See DOI: 10.1039/c4nr05519e

Tang, Yanping; Wu, Dongqing; Mai, Yiyong; Pan, Hao; Cao, Jing; Yang, Chongqing; Zhang, Fan; Feng, Xinliang

2014-11-01

181

Controlled air pyrolysis incinerator  

International Nuclear Information System (INIS)

An advanced controlled air pyrolysis incinerator has been researched, developed and placed into commercial operation for both radioactive and other combustible wastes. Engineering efforts cocentrated on providing an incinerator which emitted a clean, easily treatable off-gas and which produced a minimum amount of secondary waste. Feed material is continuously fed by gravity into the system's pyrolysis chamber without sorting, shredding, or other such pretreatment. Metal objects, liquids such as oil and gasoline, or solid products such as resins, blocks of plastic, tire, animal carcasses, or compacted trash may be included along with normal processed waste. The temperature of the waste is very gradually increased in a reduced oxygen atmosphere. Volatile pyrolysis gases are produced, tar-like substances are cracked and the resulting product, a relatively uniform, easily burnable material, is introduced into the combustion chamber. Steady burning is thus accomplished under easily controlled excess air conditions with the off-gasthen passing through a simple dry clean-up system. Gas temperatures are then reduced by air dilution before passing through final HEPA filters. Both commercial and nuclear installations have been operated with the most recent application being the central incinerator to service West Germany's nuclear reactors

182

Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: influence of lapse time of reaction.  

Science.gov (United States)

Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 degrees C) and high (400 degrees C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 degrees C was firstly aromatic products and then olefin products, while at 400 degrees C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 degrees C) and 83 min (at 400 degrees C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was concluded that the characteristics of liquid product on the pyrolysis of plastic mixtures were strongly influenced by lapse time of reaction and degradation temperature. PMID:16513339

Lee, Kyong-Hwan; Shin, Dae-Hyun

2007-01-01

183

Characteristics of liquid product from the pyrolysis of waste plastic mixture at low and high temperatures: Influence of lapse time of reaction  

International Nuclear Information System (INIS)

Pyrolysis of a waste plastic mixture (high-density polyethylene: low-density polyethylene: polypropylene: polystyrene = 3:2:3:1) into a liquid product was carried out in a stirred semi-batch reactor at low (350 deg. C) and high (400 deg. C) temperatures. The effect of lapse time of reaction in the reactor and also degradation temperature on the characteristics of the liquid product from pyrolysis of the mixture was investigated. Liquid products were described by cumulative amount distribution, paraffin, olefin, naphthene and aromatic (PONA) distribution and molecular weight distribution. Their characteristic was quite differed with a lapse time of reaction and also at a low and high degradation temperatures, because of the different physicochemical properties of the plastic types in the mixture. With increase of lapse time of reaction, the order for the main products in PONA components obtained at 350 deg. C was firstly aromatic products and then olefin products, while at 400 deg. C the order was firstly aromatic products, then olefin products and finally paraffin products. The experiments also showed from the molecular weight distribution of liquid PONA components that the paraffin and olefin products had a wide distribution by mainly random scission of polymer, but in the case of olefin products were produced by an end-chain scission mechanism as well as random scission mechanism, as evidenced by much more light olefin products. This phenomenon was evident at a highcts. This phenomenon was evident at a higher degradation temperature. Also, both the light olefin and naphthene products with a molecular weight of around 120, as a main product, showed a similar trend as a function of lapse time, which had a maximum fraction at 343 min (at 350 deg. C) and 83 min (at 400 deg. C). Among PONA components, the highest concentrations of aromatic products were obtained with a molecular weight of around 100 at the fastest lapse time of reaction, regardless of degradation temperature. It was concluded that the characteristics of liquid product on the pyrolysis of plastic mixtures were strongly influenced by lapse time of reaction and degradation temperature

184

Structural and photoluminescence characterization of SnO2: F thin films deposited by advanced spray pyrolysis technique at low substrate temperature  

International Nuclear Information System (INIS)

Fluorine doped tin oxide (FTO) thin films were deposited on glass substrates, at different substrate temperatures using advanced spray pyrolysis technique. X-ray diffraction studies showed that the crystallinity of the thin films increased with increasing substrate temperature. FESEM and AFM studies support the conclusions drawn from X-ray diffraction studies. X-ray photoelectron studies confirm oxygen deficiency in formation of the FTO nanocrystallites. The photoluminescence of the FTO films were investigated. It was found that, room temperature photoluminescence spectra are dominated by oxygen vacancies and exhibit a rich violet photoluminescence band about ?404 nm with an extensively feeble red emission about 700 nm. The Photoluminescence intensity varies with the substrate temperature. The photoemission position is observed to be independent of substrate temperature. -- Highlights: ? Photoluminescent FTO thin films were deposited at low substrate temperatures. ? Influence of substrate temperature on the PL characteristics was studied. ? The samples are polycrystalline with a cassiterite tetragonal crystal structure. ? The room temperature UV/violet PL emission was dominated by the oxygen vacancies. ? PL efficiency is optimum at 613 K substrate temperature

185

Effect of the substrate temperature on the physical properties of molybdenum tri-oxide thin films obtained through the spray pyrolysis technique  

Energy Technology Data Exchange (ETDEWEB)

Polycrystalline molybdenum tri-oxide thin films were prepared using the spray pyrolysis technique; a 0.1 M solution of ammonium molybdate tetra-hydrated was used as a precursor. The samples were prepared on Corning glass substrates maintained at temperatures ranging between 423 and 673 K. The samples were characterized through micro Raman, X-ray diffraction, optical transmittance and DC electrical conductivity. The species MoO{sub 3} (H{sub 2}O){sub 2} was found in the sample prepared at a substrate temperature of 423 K. As the substrate temperature rises, the water disappears and the samples crystallize into {alpha}-MoO{sub 3}. The optical gap diminishes as the substrate temperature rises. Two electrical transport mechanisms were found: hopping under 200 K and intrinsic conduction over 200 K. The MoO{sub 3} films' sensitivity was analyzed for CO and H{sub 2}O in the temperature range 160 to 360 K; the results indicate that CO and H{sub 2}O have a reduction character. In all cases, it was found that the sensitivity to CO is lower than that to H{sub 2}O. - Highlights: Black-Right-Pointing-Pointer A low cost technique is used which produces good material. Black-Right-Pointing-Pointer Thin films are prepared using ammonium molybdate tetra hydrated. Black-Right-Pointing-Pointer The control of the physical properties of the samples could be done. Black-Right-Pointing-Pointer A calculation method is proposed to determine the material optical properties. Black-Right-Pointing-Pointer The MoO{sub 3} thin films prepared by spray pyrolysis could be used as gas sensor.

Martinez, H.M. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Torres, J., E-mail: njtorress@unal.edu.co [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Lopez Carreno, L.D. [Grupo de Materiales con Aplicaciones Tecnologicas, Departamento de Fisica Universidad Nacional de Colombia sede Bogota (Colombia); Rodriguez-Garcia, M.E. [Departamento de Nanotecnologia, Centro de Fisica Aplicada y Tecnologia Avanzada, Universidad Nacional Autonoma de Mexico, Campus Juriquilla, Queretaro, Qro., Mexico (Colombia)

2013-01-15

186

Effect of temperature on structural, optical and photoluminescence properties of polycrystalline CuInS{sub 2} thin films prepared by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Copper indium disulphide (CuInS{sub 2}), is a good absorber material for photovoltaic applications. In this work, CuInS{sub 2} is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS{sub 2} thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS{sub 2} films. The XRD patterns confirm the well defined single phase composition of CuInS{sub 2} films grown from 300 to 350 deg. C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS{sub 2} thin films with chalcopyrite structure. D{sub 2d} point symmetry group is associated with the CuInS{sub 2} crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS{sub 2} films is found to be in the order of 10{sup 5}-10{sup 6} cm{sup -1} in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS{sub 2} polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.

Mahendran, C. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu (India); Suriyanarayanan, N., E-mail: esnsuri@yahoo.co.i [Department of Physics, Government College of Technology, Coimbatore 641 013, Tamil Nadu (India)

2010-04-15

187

Effect of temperature on structural, optical and photoluminescence properties of polycrystalline CuInS 2 thin films prepared by spray pyrolysis  

Science.gov (United States)

Copper indium disulphide (CuInS 2), is a good absorber material for photovoltaic applications. In this work, CuInS 2 is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS 2 thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS 2 films. The XRD patterns confirm the well defined single phase composition of CuInS 2 films grown from 300 to 350 C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS 2 thin films with chalcopyrite structure. D 2d point symmetry group is associated with the CuInS 2 crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS 2 films is found to be in the order of 10 5-10 6 cm -1 in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS 2 polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.

Mahendran, C.; Suriyanarayanan, N.

2010-04-01

188

Effect of temperature on structural, optical and photoluminescence properties of polycrystalline CuInS2 thin films prepared by spray pyrolysis  

International Nuclear Information System (INIS)

Copper indium disulphide (CuInS2), is a good absorber material for photovoltaic applications. In this work, CuInS2 is deposited by chemical spray pyrolysis on heated glass substrates. It is observed that the film growth temperature and the ion ratio Cu/In affects the structural and optical properties of CuInS2 thin films. This paper presents the effect of temperature on the growth (for the ion ratio Cu/In=1.25), optical and photoluminescence properties of sprayed CuInS2 films. The XRD patterns confirm the well defined single phase composition of CuInS2 films grown from 300 to 350 deg. C (at Cu/In=1.25) as optimum temperature for depositing well defined crystallites along (1 1 2) oriented CuInS2 thin films with chalcopyrite structure. D2d point symmetry group is associated with the CuInS2 crystallites with energy gap of 1.53 eV at room temperature. The chemical nature and the presence of additional phases are discussed based on the EDAX measurements. The absorption coefficient of sprayed CuInS2 films is found to be in the order of 105-106 cm-1 in the UV-visible region and the optical band gap decreases with increase in temperature. Defects-related photoluminescence properties are also discussed. CuInS2 polycrystalline films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of copper (II) chlm the aqueous solutions of copper (II) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.

189

Time resolved pyrolysis of char  

DEFF Research Database (Denmark)

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 slow heating in direct combination with mass spectrometry, gas chromatography/mass spectrometry and flame ionization detection, respectively. Characteristic ions derived from the flash pyrolysis-gas chromatography/mass spectrometry data enable the release of volatiles to be time and, hence, temperature resolved.

Egsgaard, Helge; Ahrenfeldt, Jesper

190

Effect of Substrate Temperature on the Growth of Polycrystalline ZnS Thin Films Prepared by Spray Pyrolysis Technique  

OpenAIRE

ZnS thin films on glass substrate have been prepared by home built spray pyrolysis technique at 220, 250 and 280C. Aqueous solution of 50 mL containing zinc acetate dihydrate and thiourea salts of 1:1 M is sprayed as fine mist at a pressure of 2 kg cm-2 with flow rate of 3 mL min-1 on preheated glass substrate. Film obtained at 220C found to be amorphous and polycrystalline at 250 and 280C with preferential orientation along (111) plane. X-ray line broadening technique is utilized to de...

Chandiramouli, R.; Jeyaprakash, B. G.; Balamurugan, D.

2012-01-01

191

Direct Synthesis of Fe3C-Functionalized Graphene by High Temperature Autoclave Pyrolysis for Oxygen Reduction  

DEFF Research Database (Denmark)

We present a novel approach to direct fabrication of few-layer graphene sheets with encapsulated Fe3C nanoparticles from pyrolysis of volatile non-graphitic precursors without any substrate. This one-step autoclave approach is facile and potentially scalable for production. Tested as an electrocatalyst, the graphene-based composite exhibited excellent catalytic activity towards the oxygen reduction reaction in alkaline solution with an onset potential of ca. 1.05 V (vs. the reversible hydrogen electrode) and a half-wave potential of 0.83 V, which is comparable to the commercial Pt/C catalyst.

Hu, Yang; Jensen, Jens Oluf

2014-01-01

192

A new approach for reduction of methylene green withascorbic acid by de-oxygenation through carbondioxide  

Directory of Open Access Journals (Sweden)

Full Text Available Reduction kinetics of the methylene green (MG with ascorbic acid (AA in acidic medium at ?max 660 nm was monitored through visible spectrophotomtry in absence and presence of sodium carbonate. CO2 release through reaction of sodium carbonate and oxalic acid, created deoxygenated atmosphere for reduction of dye which greatly boosted the reaction rate. Initially slow reaction in presence of atmospheric oxygen proceeded rapidly when sodium carbonate was added. The reaction followed fractional order kinetics with AA and zero order kinetics with MG. The rate of reaction shows no linear dependence on [H+] concentration as an acidic medium. The rate of reaction is directly related with the elevated concentration of salt, which suggests that the two same charged species are involved in the rate determining step. Secondary reactions at elevated temperature showed complex kinetics.

Rafia Azmat

2011-07-01

193

PYROLYSIS OF TOBACCO RESIDUE: PART 1. THERMAL  

OpenAIRE

The pyrolysis of two types of tobacco residue was carried out at different pyrolysis temperatures between 300 and 600 C and a residence time of 1 h in a nitrogen atmosphere. The effect of pyrolysis temperature on the product distributions was investigated and the composition of the bio-oils identified. The variation in product distribution depended on both the temperature and the type of tobacco residues. The maximum liquid yields were obtained at 400C for one sample and at 500C for the...

Akalin, Mehmet K.; Selhan Karagz

2011-01-01

194

Analysis of pyrolysis products of methamphetamine.  

Science.gov (United States)

This study examined the pyrolysis products of d-methamphetamine (d-MA) and the pyrolysis mechanism. A sealed glass tube, in which MA-HCl was placed, was wrapped with pyrolysis-foil and heated at the Curie point of the pyrolysis-foil. The pyrolysis products of MA were detected by gas chromatography-mass spectrometry and liquid chromatography-electrospray ionization-mass spectrometry. MA-d(3)-HCl, in which all the hydrogen atoms of N-methyl group of MA were substituted with deuterium atoms, was pyrolyzed to investigate the transformation of a methyl group of MA. Amphetamine (AM) and dimethylamphetamine (DMA) were produced via demethylation and methylation reactions, respectively, at temperatures above 315 degrees C. The demethylation and methylation reactions were the major pyrolysis processes at temperatures below 358 degrees C. At temperatures above 315 degrees C, the reaction of DMA with a methyl group eliminated from the methylamino group of MA resulted in the formation of benzylethyltrimethylammonium (BEMA). This transformation reveals that demethylation and methylation reactions occur in the form of a methyl cation. The thermal degradation of BEMA, the abstraction of a proton at the beta-position and the elimination of a trimethylamine, produced allylbenzene, cis-beta-methylstyrene, and trans-beta-methylstyrene at temperatures above 315 degrees C. At temperatures above 445 degrees C, the optical isomers, or l-isomers of AM, MA, and DMA, were produced as pyrolysis products. PMID:15538957

Sato, Motoyasu; Hida, Minemasa; Nagase, Hisamitsu

2004-01-01

195

Transportation fuels from biomass via fast pyrolysis and hydroprocessing  

Energy Technology Data Exchange (ETDEWEB)

Biomass is a renewable source of carbon, which could provide a means to reduce the greenhouse gas impact from fossil fuels in the transportation sector. Biomass is the only renewable source of liquid fuels, which could displace petroleum-derived products. Fast pyrolysis is a method of direct thermochemical conversion (non-bioconversion) of biomass to a liquid product. Although the direct conversion product, called bio-oil, is liquid; it is not compatible with the fuel handling systems currently used for transportation. Upgrading the product via catalytic processing with hydrogen gas, hydroprocessing, is a means that has been demonstrated in the laboratory. By this processing the bio-oil can be deoxygenated to hydrocarbons, which can be useful replacements of the hydrocarbon distillates in petroleum. While the fast pyrolysis of biomass is presently commercial, the upgrading of the liquid product by hydroprocessing remains in development, although it is moving out of the laboratory into scaled-up process demonstration systems.

Elliott, Douglas C.

2013-09-21

196

Optimization of multi-stage pyrolysis  

International Nuclear Information System (INIS)

Pyrolysis process is considered as a beneficial option in waste treatment largely due to the products generated and the energy recovery when compared to other methods. In the conventional pyrolysis process, heat is continually supplied to the reactor until the final pyrolysis temperature is attained. The reactor is then maintained isothermally at this temperature until the pyrolysis is completed. This technique does not take into consideration the mechanism of the pyrolysis which involves both exothermic and endothermic reaction and the opportunity of gaining some processing benefits is often ignored. Multi-stage pyrolysis which is an approach to carry out pyrolysis with multiple heating stages in order to gain certain processing benefits has been introduced in our earlier works. 22.5% energy reduction was achieved in our past work with a 100% increase in completion time. This work therefore proposes the optimization of the operating parameters in multi-stage pyrolysis in order to limit the increase in completion time and also reduces the overall energy. This innovative approach can achieve a range of 24.7%37.9% reduction in energy usage with 37%50% increase in completion time depending on the heating rate for each heating stages. This approach has also been used for charcoal production

197

High electron mobility thin-film transistors based on Ga2O3 grown by atmospheric ultrasonic spray pyrolysis at low temperatures  

Science.gov (United States)

We report on thin-film transistors based on Ga2O3 films grown by ultrasonic spray pyrolysis in ambient atmosphere at 400-450 C. The elemental, electronic, optical, morphological, structural, and electrical properties of the films and devices were investigated using a range of complementary characterisation techniques, whilst the effects of post deposition annealing at higher temperature (700 C) were also investigated. Both as-grown and post-deposition annealed Ga2O3 films are found to be slightly oxygen deficient, exceptionally smooth and exhibit a wide energy bandgap of 4.9 eV. Transistors based on as-deposited Ga2O3 films show n-type conductivity with the maximum electron mobility of 2 cm2/V s.

Thomas, Stuart R.; Adamopoulos, George; Lin, Yen-Hung; Faber, Hendrik; Sygellou, Labrini; Stratakis, Emmanuel; Pliatsikas, Nikos; Patsalas, Panos A.; Anthopoulos, Thomas D.

2014-09-01

198

Potential method for gas production: high temperature co-pyrolysis of lignite and sewage sludge with vacuum reactor and long contact time.  

Science.gov (United States)

Lignite and sewage sludge were co-pyrolyzed in a vacuum reactor with high temperature (900C) and long contact time (more than 2h). Beneficial synergetic effect on gas yield was clearly observed. Gas yield of blend fuel was evidently higher than that of both parent fuels. The gas volume yield, gas lower heating value (LHV), fixed carbon conversion and H2/CO ratio were 1.42 Nm(3)/kg(blend fuel), 10.57 MJ/Nm(3), 96.64% and 0.88% respectively, which indicated this new method a feasible one for gas production. It was possible that sewage sludge acted as gasification agents (CO2 and H2O) and catalyst (alkali and alkaline earth metals) provider during co-pyrolysis, promoting CO2-char and H2O-char gasification which, as a result, invited the improvement of gas volume yield, gas lower heating value and fixed carbon conversion. PMID:25542402

Yang, Xiao; Yuan, Chengyong; Xu, Jiao; Zhang, Weijiang

2015-03-01

199

High electron mobility thin-film transistors based on Ga{sub 2}O{sub 3} grown by atmospheric ultrasonic spray pyrolysis at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

We report on thin-film transistors based on Ga{sub 2}O{sub 3} films grown by ultrasonic spray pyrolysis in ambient atmosphere at 400450?C. The elemental, electronic, optical, morphological, structural, and electrical properties of the films and devices were investigated using a range of complementary characterisation techniques, whilst the effects of post deposition annealing at higher temperature (700?C) were also investigated. Both as-grown and post-deposition annealed Ga{sub 2}O{sub 3} films are found to be slightly oxygen deficient, exceptionally smooth and exhibit a wide energy bandgap of ?4.9?eV. Transistors based on as-deposited Ga{sub 2}O{sub 3} films show n-type conductivity with the maximum electron mobility of ?2?cm{sup 2}/V s.

Thomas, Stuart R., E-mail: s.thomas09@imperial.ac.uk, E-mail: thomas.anthopoulos@imperial.ac.uk; Lin, Yen-Hung; Faber, Hendrik; Anthopoulos, Thomas D., E-mail: s.thomas09@imperial.ac.uk, E-mail: thomas.anthopoulos@imperial.ac.uk [Department of Physics, Blackett Laboratory, Imperial College London, London SW7 2BW (United Kingdom); Adamopoulos, George [Department of Engineering, Engineering Building, Lancaster University, Bailrigg, Lancaster LA1 4YR (United Kingdom); Sygellou, Labrini [Institute of Chemical Engineering and High Temperature Processes (ICEHT), Foundation of Research and Technology Hellas (FORTH), Stadiou Strasse Platani, P.O. Box 1414, Patras GR-265 04 (Greece); Stratakis, Emmanuel [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), Heraklion 71003 (Greece); Materials Science and Technology Department, University, of Crete, Heraklion 71003 (Greece); Pliatsikas, Nikos; Patsalas, Panos A. [Laboratory of Applied Physics, Department of Physics, Aristotle University of Thessaloniki, Thessaloniki GR-54124 (Greece)

2014-09-01

200

Effects of synthesis conditions on Curie temperature of La0.75Sr0.25MnO3 fine particles formed by ultrasonic spray pyrolysis  

Science.gov (United States)

Manganese perovskite La0.75Sr0.25MnO3 (LSM) fine particles were synthesized by an ultrasonic spray pyrolysis method at various synthesis temperatures (Ts), reaction times (tr), and source solution concentrations (Ctotal) to clarify the effects of these synthesis conditions on their Curie temperature Tc and maximum particle temperature attained by magnetic heating at Thmax. At constant Ctotal, the Tc of synthesized LSM particles was increased from 288.6 to 363.5 K (15.6 to 90.5 C) by increasing Ts from 1073 to 1627 K (800 to 1400 C), and was increased from 281.8 to 339 K (8.89 to 66 C) by increasing tr from 2.4 to 19 s. When the AC magnetic field was applied, the particles generated heat, and the particle temperature Th increased with time for t < about 2 min, and then attained constant Thmax near Tc. Thmax increased with increasing Tc. The LSM particles produced at Ts = 1213 K, Ctotal = 0.5 mol L-1, and tr = 9.4 s had Thmax = 316.6 K (43.6 C), which is within the temperature range of 316-318 K (43-45 C) for hyperthermia therapy for cancer.

Kinoshita, Takuya; Furuyabu, Takamitsu; Adachi, Motoaki

2014-10-01

201

Pyrolysis and gasification of coal at high temperatures. Final technical report, September 15, 1987--September 14, 1991  

Energy Technology Data Exchange (ETDEWEB)

The macropore structure of chars is a major factor in determining their reactivity during the gasification stage. The major objectives of this contract were to (a) quantify by direct measurements the effect of pyrolysis conditions of the macropore structure, and (b) establish how the macropores affected the reactivity pattern, the ignition behavior and the fragmentation of the char particles during gasification in the regime of strong diffusional limitations. Results from this project provide much needed information on the factors that affect the quality of the solid products (chars) of coal utilization processes (for example, mild gasification processes). The reactivity data will also provide essential parameters for the optimal design of coal gasification processes. (VC)

Zygourakis, K.

1992-02-10

202

Effect of Annealing Temperature on Structural, Optical and Electrical Properties of Pure CdS Thin Films Deposited by Spray Pyrolysis Technique  

Directory of Open Access Journals (Sweden)

Full Text Available

Effect of annealing temperature on the properties of CdS thin films are carried out in this work. Nanocrystalline cadmium sulphide (CdS thin films were prepared using spray pyrolysis deposition (SPD technique and the structural, optical and electrical properties were investigated for different annealing temperature (as deposited, 300, 400 & 500 C. The surface morphology and compositional properties studied by SEM and EDX respectively. The crystal structure of CdS thin film was studied by X-ray diffraction. The crystallite size and lattice constant of SPD CdS thin films were investigated. The optical parameters such as transmittance, absorption coefficient and energy band gap of the films with thermal annealing temperature was investigated by UV/VIS spectrophotometer. The variation of band gap values of CdS thin film samples were found to be in the range of 2.51 to 2.8 eV. Electrical resistivity measurements were carried out in fourprobe Vander Pauw method at different temperature. So CdS films may be a good candidate for suitable application in various optoelectronic devices.

2012-12-01

203

FAST PYROLYSIS OF ENZYMATIC/MILD ACIDOLYSIS LIGNIN FROM MOSO BAMBOO  

OpenAIRE

The characteristics of enzymatic/mild acidolysis lignin (EMAL) isolated from moso bamboo were investigated using pyrolysis-gas chromato-graphy/mass spectrometry (Py-GC/MS). Pyrolysis temperature as a factor on products was studied, and the pyrolysis mechanism was inferred with respect to the dominating products. Research results showed that pyrolysis products derived from EMAL pyrolysis were mainly heterocyclic (2,3-dihydrobenzofuran), phenols, esters, and a minor amount of acetic acid. Pyrol...

Rui Lou; Shu-bin Wu; Gao-jin Lv

2010-01-01

204

Slow pyrolysis of pistachio shell  

Energy Technology Data Exchange (ETDEWEB)

In this study, pistachio shell is taken as the biomass sample to investigate the effects of pyrolysis temperature on the product yields and composition when slow pyrolysis is applied in a fixed-bed reactor at atmospheric pressure to the temperatures of 300, 400, 500, 550, 700{sup o}C. The maximum liquid yield was attained at about 500-550{sup o}C with a yield of 20.5%. The liquid product obtained under this optimum temperature and solid products obtained at all temperatures were characterized. As well as proximate and elemental analysis for the products were the basic steps for characterization, column chromatography, FT-IR, GC/MS and SEM were used for further characterization. The results showed that liquid and solid products from pistachio shells show similarities with high value conventional fuels. 31 refs., 9 figs., 1 tab.

Esin Apaydin-Varol; Ersan Putun; Ayse E. Putun [Anadolu University, Eskisehir (Turkey). Department of Chemical Engineering

2007-08-15

205

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

DEFF Research Database (Denmark)

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 temperature varied in the range 673?1673 K for slow pyrolysis and between 873 and 1573 K for fast pyrolysis. The chars were oxidized in a thermogravimetric analyzer and the mass loss data were used to determine char oxidation reactivity. Char yield from fast pyrolysis (104?105 K/s) was as low as 1 to 6% on a dry ash free basis, whereas it was about 15?17% for slow pyrolysis (10?20 K/min); char yield decreased as pyrolysis temperature increased. During fast pyrolysis wood particles underwent melting, yet to different extents for the two investigated fuels: pine wood produced chars of porous spherical particles, whereas beech sawdust chars showed a somewhat less drastic change of morphology with respect to the parent fuel. Char produced by low heating rate pyrolysis fully retained the original fibrous structure of wood. Fast pyrolysis chars were significantly more reactive than slow pyrolysis chars; moreover, char oxidation reactivity decreased as pyrolysis temperature increased. The amount and composition of the ash forming matter of the wood fuels seems to play an important role in determining the differences in char yield, morphology and reactivity.

Dall'Ora, Michelangelo; Jensen, Peter Arendt

2008-01-01

206

Effects of torrefaction and densification on switchgrass pyrolysis products  

Energy Technology Data Exchange (ETDEWEB)

Abstract The pyrolysis behaviors of four types of pretreated switchgrass (torrefied at 230 and 270 C, densification, and torrefaction at 270 C followed by densification) were studied at three temperatures (500, 600, 700 C) using a pyroprobe attached to a gas chromatogram mass spectroscopy (Py-GC/MS). The torrefaction of switchgrass improved its oxygen to carbon ratio and energy content. Contents of anhydrous sugars and phenols in pyrolysis products of torrefied switchgrass were higher than those in pyrolysis products of raw switchgrass. As the torrefaction temperature increased from 230 to 270 C, the contents of anhydrous sugars and phenols in pyrolysis products increased whereas content of guaiacols decreased. High pyrolysis temperature (600 and 700 C as compared to 500 C) enhanced decomposition of lignin and anhydrous sugars, leading to increase in phenols, aromatics and furans. Densification enhanced depolymerization of cellulose and hemicellulose during pyrolysis.

Yang, Z; Sarkar, M; Kumar, A; Jaya Shankar Tumuluru; R.L. Huhnke

2014-10-01

207

Effects of torrefaction and densification on switchgrass pyrolysis products.  

Science.gov (United States)

The pyrolysis behaviors of four types of pretreated switchgrass (torrefied at 230 and 270C, densification, and torrefaction at 270C followed by densification) were studied at three temperatures (500, 600, 700C) using a pyroprobe attached to a gas chromatogram mass spectroscopy (Py-GC/MS). The torrefaction of switchgrass improved its oxygen to carbon ratio and energy content. Contents of anhydrous sugars and phenols in pyrolysis products of torrefied switchgrass were higher than those in pyrolysis products of raw switchgrass. As the torrefaction temperature increased from 230 to 270C, the contents of anhydrous sugars and phenols in pyrolysis products increased whereas content of guaiacols decreased. High pyrolysis temperature (600 and 700C as compared to 500C) enhanced decomposition of lignin and anhydrous sugars, leading to increase in phenols, aromatics and furans. Densification enhanced depolymerization of cellulose and hemicellulose during pyrolysis. PMID:25463807

Yang, Zixu; Sarkar, Madhura; Kumar, Ajay; Tumuluru, Jaya Shankar; Huhnke, Raymond L

2014-12-01

208

Role of substrate temperature on the properties of Na-doped ZnO thin film nanorods and performance of ammonia gas sensors using nebulizer spray pyrolysis technique  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Na-doped ZnO films deposited on glass by nebulizer spray pyrolysis (NSP) method. NSP method for large area coatings and good results as compared with other methods. HR-SEM studies reveal the formation of Na-doped ZnO films consisting of nano-rods. Na-doped ZnO films ensure their stability and suitability for gas sensors. -- Abstract: Sodium doped zinc oxide (Na:ZnO) thin films were deposited on glass substrates at substrate temperatures 300, 400 and 500 C by a novel nebulizer spray method. X-ray diffraction shows that all the films are polycrystalline in nature having hexagonal structure with high preferential orientation along (0 0 2) plane. High resolution SEM studies reveal the formation of Na-doped ZnO films having uniformly distributed nano-rods over the entire surface of the substrates at 400 C. The complex impedance of the ZnO nano-rods shows two distinguished semicircles and the diameter of the arcs got decreased in diameter as the temperature increases from 170 to 270 C and thereafter slightly increased.

Mariappan, R., E-mail: marijpr@gmail.com [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu (India); Department of Physics, Adhiyamaan College of Engineering, Hosur 635 109, Tamilnadu (India); Ponnuswamy, V.; Suresh, R. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu (India); Suresh, P. [Materials Research Centre, Indian Institute of Science, Bangalore 560 012 (India); Chandra Bose, A. [Department of Physics, National Institute of Technology, Tiruchirappalli 620 015, Tamil Nadu (India); Ragavendar, M. [Department of Physics, KPR Institute of Engineering and Technology, Coimbatore 641 407, Tamil Nadu (India)

2014-01-05

209

Role of substrate temperature on the properties of Na-doped ZnO thin film nanorods and performance of ammonia gas sensors using nebulizer spray pyrolysis technique  

International Nuclear Information System (INIS)

Highlights: Na-doped ZnO films deposited on glass by nebulizer spray pyrolysis (NSP) method. NSP method for large area coatings and good results as compared with other methods. HR-SEM studies reveal the formation of Na-doped ZnO films consisting of nano-rods. Na-doped ZnO films ensure their stability and suitability for gas sensors. -- Abstract: Sodium doped zinc oxide (Na:ZnO) thin films were deposited on glass substrates at substrate temperatures 300, 400 and 500 C by a novel nebulizer spray method. X-ray diffraction shows that all the films are polycrystalline in nature having hexagonal structure with high preferential orientation along (0 0 2) plane. High resolution SEM studies reveal the formation of Na-doped ZnO films having uniformly distributed nano-rods over the entire surface of the substrates at 400 C. The complex impedance of the ZnO nano-rods shows two distinguished semicircles and the diameter of the arcs got decreased in diameter as the temperature increases from 170 to 270 C and thereafter slightly increased

210

Pyrolysis of composite plastic waste.  

Science.gov (United States)

Several different composite plastics were pyrolysed in a fixed bed reactor at final temperatures between 350 and 800 degrees C. The composites studied were polyester, phenolic, epoxy, vinylester, polypropylene and PET resins, reinforced with glass and/or carbon fibre. The product yields of oil gas and solid residue were determined together with a detailed composition of the derived gases. There was evidence to suggest that calcium carbonate filler, present in the polyester and phenolic composites, decomposed to form carbon dioxide at 800 degrees C, which was subsequently involved in char gasification reactions. Polyester, phenolic and epoxy composites generated highly aromatic, oxygenated condensable products. There was no noticeable correlation between the composition of these products and the final pyrolysis temperature. The tensile strength of recovered glass fibre was lower than that of virgin fibre and decreased markedly as the final pyrolysis temperature increased from 650 to 800 degrees C. PMID:12803257

Cunliffe, A M; Jones, N; Williams, P T

2003-05-01

211

Behavior of sulfur during coal pyrolysis  

Science.gov (United States)

The behavior of sulfur in Illinois coals during pyrolysis was evaluated by thermogravimetry/ Fourier transform-infrared spectroscopy (TG/FT-IR) techniques. SO2, COS, and H2S were major gaseous sulfur-containing products observed during coal pyrolysis. The release rates of the gaseous sulfur species showed several peaks within the temperature ranges, which were due to the emission of different forms of sulfur in coal. ?? 1994.

Shao, D.; Hutchinson, E.J.; Heidbrink, J.; Pan, W.-P.; Chou, C.-L.

1994-01-01

212

Vacuum pyrolysis of automobile shredder residues  

Energy Technology Data Exchange (ETDEWEB)

A research program was undertaken to evaluate the overall performance of a vacuum pyrolysis process applied to the treatment of Automobile Shredder Residues (ASR). North American and European ASR samples were tested. Vacuum pyrolysis experiments were carried out in the temperature range of 496-536C and a total pressure of approx. 1-5 kPa. Pyrolysis product yields averaged 52.5 wt.% solid residue, 27.7 wt.% organic liquids, 13.3 wt.% pyrolytic water and 6.6 wt.% pyrolysis gas. Composition of ASR feedstocks and pyrolysis products has been thoroughly characterized. After pyrolysis, ASR volume and weight were reduced 5x and 1.8x, respectively. It was possible to readily recover 14 wt.% of useful metals remaining in the solid residues; the material left over can be safely landfilled. Pyrolytic gas and oil can be used as heating fuels. The heavy fraction of the oil (>400C) can be added to road bitumens in order to improve their performance. The total oil also represents a challenging matrix for various purposes. The vacuum pyrolysis technology can be seen as an alternative to landfill and incineration.

Roy, C.; Chaala, A. [Institut Pyrovac Inc., Parc technologique du Quebec metropolitain, 333, rue Franquet, Sainte-Foy, G1P 4C7 Quebec (Canada)

2001-05-01

213

Pyrolysis of spent ion-exchanger resins  

Energy Technology Data Exchange (ETDEWEB)

Initial tests have shown that ion exchangers (IEX) can be decomposed by pyrolysis with very good results, yielding an inert and chemically resistant product. No additives are necessary. The main constituent of the product, the pyrolysis residues or ash, is carbon. It has been discovered that the entire radioactive inventory remains in the pyrolysis residues during pyrolysis of the IEX. This is achieved by relatively low process temperatures that prevent highly volatile nuclides such as the caesium nuclides from passing into the gaseous phase. Sintered metal filters in pyrolysis plant ensure that even the radioactivity bonded to the dust remains in the pyrolysis residues. In addition to the radionuclides, the main constituents of the residue are carbon from the original polystyrene matrix and sulphur from the functional groups. The pyrolysis residues form a flowable solid material and not a melt. It is thus easy to handle and can be compacted or cemented, depending on the requirements for interim and permanent storage. Any further constituents such as inorganic filter materials or even other organic materials do not interfere with the process, they are dried, calcined or also pyrolysed. (orig.)

Slametschka, Rainer; Braehler, Georg [NUKEM Technologies GmbH (Germany)

2012-11-01

214

Derivation of hydrous pyrolysis kinetic parameters from open-system pyrolysis  

Science.gov (United States)

Kinetic information is essential to predict the temperature, timing or depth of hydrocarbon generation within a hydrocarbon system. The most common experiments for deriving kinetic parameters are mainly by open-system pyrolysis. However, it has been shown that the conditions of open-system pyrolysis are deviant from nature by its low near-ambient pressure and high temperatures. Also, the extrapolation of heating rates in open-system pyrolysis to geological conditions may be questionable. Recent study of Lewan and Ruble shows hydrous-pyrolysis conditions can simulate the natural conditions better and its applications are supported by two case studies with natural thermal-burial histories. Nevertheless, performing hydrous pyrolysis experiment is really tedious and requires large amount of sample, while open-system pyrolysis is rather convenient and efficient. Therefore, the present study aims at the derivation of convincing distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data. Our results unveil that there is a good correlation between open-system Rock-Eval parameter Tmax and the activation energy (Ea) derived from hydrous pyrolysis. The hydrous pyrolysis single Ea can be predicted from Tmax based on the correlation, while the frequency factor (A0) is estimated based on the linear relationship between single Ea and log A0. Because the Ea distribution is more rational than single Ea, we modify the predicted single hydrous pyrolysis Ea into distributed Ea by shifting the pattern of Ea distribution from open-system pyrolysis until the weight mean Ea distribution equals to the single hydrous pyrolysis Ea. Moreover, it has been shown that the shape of the Ea distribution is very much alike the shape of Tmax curve. Thus, in case of the absence of open-system Ea distribution, we may use the shape of Tmax curve to get the distributed hydrous pyrolysis Ea. The study offers a new approach as a simple method for obtaining distributed hydrous pyrolysis Ea with only routine open-system Rock-Eval data, which will allow for better estimating hydrocarbon generation.

Tseng, Yu-Hsin; Huang, Wuu-Liang

2010-05-01

215

An investigation on substrate temperature and copper to sulphur molar ratios on optical and electrical properties of nanostructural CuS thin films prepared by spray pyrolysis method  

International Nuclear Information System (INIS)

Copper sulphide (CuS) thin films have been deposited on glass substrates by spray pyrolysis method using an aqueous solutions of copper (II) acetate and thiourea with different Cu to S molar ratios (0.33 and 0.43) at various substrate temperatures of 260, 285 and 310 C. The structural, optical and electrical characterizations have been carried out using XRD, UV-Vis. transmittance/reflectance, PL spectra and Hall effect measurements. These characterizations indicated the formation of a CuS single phase (covellite) with polycrystalline nature with preferred orientation along (1 0 2) plane, except one with amorphous nature. Optical studies showed that the deposited layers have a relatively high absorption coefficient (5 104 to 1 105 cm-1) in the visible range, with an effective optical band gap of ?2.4-2.6 eV. The Hall effect data showed that all the grown samples have a degenerate p-type conductivity with a hole concentration of ?1.8 1020 to 1.7 1021 cm-3.

216

Orientation-dependent low field magnetic anomalies and room-temperature spintronic material Mn doped ZnO films by aerosol spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: Optical microscopy images of Mn doped ZnO films deposited for 20 min. Highlights: MnZnO films showing transparent spherical bubbles were synthesized by ASP. LFMA phenomenon was observed for these films. A relatively novel reversal magnetic feature to that of LFMA was observed. Ferromagnetic to paramagnetic transition due to Mn doping was observed. Angular dependence analysis showed evidence of magnetic anisotropy present. -- Abstract: High quality un-doped and Mn-doped ZnO films deposited by a simple aerosol spray pyrolysis technique for 20 and 30 min were studied using electron paramagnetic resonance (EPR), X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques. EPR analysis showed novel observation of low field microwave absorption (LFMA) on the manganese (Mn) doped zinc oxide (ZnO) films at various Mn concentrations. The results showed a peculiar behavior, reversal signal to that of LFMA. These findings also demonstrated that these films contain ferromagnetism at room temperature with possible applications in spintronics. Angular dependence measurements were found to induce magnetic transition from ferromagnetism to paramagnetism. Structural analysis showed that the undertaken materials are in wurtzite structures. The light absorption edge of MnZnO films red shifted which enhanced the observed ferromagnetism. The direct modulation of the band gap caused by MnZnO substitution is responsible for the red shift effect in absorption edge of ZnO.

Nkosi, S.S. [CSIR-National Laser Centre, 626 Meiring Naude Rd, Brummeria, Pretoria 0001 (South Africa); School of Physics, University of Witwatersrand, Private Bag X3, Johannesburg 2030 (South Africa); Kortidis, I. [Institute of Electronic Structure and Laser, Foundation for Research and Technology, Hellas, P.O. Box 1527, 71110 Heraklion, Crete (Greece); Motaung, D.E., E-mail: dmotaung@csir.co.za [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001 (South Africa); Malgas, G.F. [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001 (South Africa); Department of Physics, University of the Western Cape, Private Bag X17, Bellville, 7535 (South Africa); Keartland, J.; Sideras-Haddad, E. [School of Physics, University of Witwatersrand, Private Bag X3, Johannesburg 2030 (South Africa); Forbes, A. [CSIR-National Laser Centre, 626 Meiring Naude Rd, Brummeria, Pretoria 0001 (South Africa); School of Physics, University of Witwatersrand, Private Bag X3, Johannesburg 2030 (South Africa); Mwakikunga, B.W., E-mail: bmwakikunga@csir.co.za [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001 (South Africa); Sinha-Ray, S. [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria 0001 (South Africa); Kiriakidis, G. [Institute of Electronic Structure and Laser, Foundation for Research and Technology, Hellas, P.O. Box 1527, 71110 Heraklion, Crete (Greece)

2013-12-05

217

Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing  

Science.gov (United States)

We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

Motaung, D. E.; Mhlongo, G. H.; Kortidis, I.; Nkosi, S. S.; Malgas, G. F.; Mwakikunga, B. W.; Ray, S. Sinha; Kiriakidis, G.

2013-08-01

218

Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing  

Energy Technology Data Exchange (ETDEWEB)

We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

Motaung, D.E., E-mail: dmotaung@csir.co.za [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P. O. Box 395, Pretoria 0001 (South Africa); Mhlongo, G.H., E-mail: gmhlongo@csir.co.za [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P. O. Box 395, Pretoria 0001 (South Africa); Kortidis, I. [Transparent Conductive Materials Lab, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, 100N. Plastira str., Vassilika Vouton, 70013 Heraklion, Crete (Greece); Nkosi, S.S., E-mail: skosi@csir.co.za [CSIR-National Laser Centre, 626 Meiring Naude Rd, Brummeria, Pretoria 0001 (South Africa); School of Physics, University of Witwatersrand, Private Bag X3, Johannesburg 2030 (South Africa); Malgas, G.F.; Mwakikunga, B.W.; Ray, S.Sinha [DST/CSIR Nanotechnology Innovation Centre, National Centre for Nano-Structured Materials, Council for Scientific and Industrial Research, P. O. Box 395, Pretoria 0001 (South Africa); Kiriakidis, G., E-mail: kiriakid@iesl.forth.gr [Transparent Conductive Materials Lab, Institute of Electronic Structure and Laser, Foundation for Research and Technology Hellas, 100N. Plastira str., Vassilika Vouton, 70013 Heraklion, Crete (Greece); University of Crete, Department of Physics, 710 03 Heraklion, Crete (Greece)

2013-08-15

219

Strong room-temperature ultraviolet emission from nanocrystalline ZnO and ZnO:Ag films grown by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

Nanocrystalline ZnO and ZnO:Ag films have been deposited on Si (1 0 0) substrates by ultrasonic spray pyrolysis (USP) technique under ambient atmosphere. Among pure ZnO films, the sample deposited at 500 oC with spray rate of 0.15 ml/min has the strongest near-band edge (NBE) ultraviolet emission (378 nm) observed in the room-temperature photoluminescence (RT PL) measurement. Its PL intensity ratio (R) of the UV emission to the deep-level emission has a largest value of 470 and the full-width at half-maximum (FWHM) of UV peak has a smallest value of 10 nm (87 meV). Moreover, RT PL spectra show that compared with undoped ZnO, the UV emission intensity of ZnO:Ag films (with the Ag:Zn atomic ratio = 3% in the precursor solution) is even markedly enhanced and the R increases to the value of at least 700. However, a silver phase is detected and the UV luminescence becomes weak for ZnO:Ag films after the annealing at 700 oC in air for 1 h.

220

Preparation and characterization of nanostructures of in-doped ZnO films deposited by chemically spray pyrolysis: Effect of substrate temperatures  

Science.gov (United States)

We deposited undoped (ZnO) and indium-doped ZnO (IZO) films onto glass substrate via ultrasonic spray pyrolysis technique. The variation in structural, surface morphology, electrical, optical and photoluminescent properties as a function of substrate temperature is investigated. X-rays pattern confirms that as-synthesized IZO phase is grown along a (002) preferential plane. Nanosized grains (<50 nm) are determined by X-ray analysis. Morphology of as-grown films shows broadened nanostructures which have grown along c-axis and nanostructures are found to be smooth (RMS60 nm). Study by spectrophotometer reveals that the as-grown films are highly transparent in the visible and IR spectra (T 88%), and that the bandgap is slightly narrowed (3.17 eV). Electrical measurements confirm the enhancement of conductivity, ? < 1 ? cm, due to indium incorporation into the starting solution. An electron concentration of 1017 cm-3 and a mobility of 3 cm2/Vs are found for IZO films grown at 400 C. The photoluminescence analysis demonstrates strong yellow (2.1 eV) and blue (2.8 eV) light and weak green (2.3 eV) emissions.

Benhaliliba, M.; Benouis, C. E.; Mouffak, Z.; Ocak, Y. S.; Tiburcio-Silver, A.; Aida, M. S.; Garcia, A. A.; Tavira, A.; Sanchez Juarez, A.

2013-11-01

221

An investigation on substrate temperature and copper to sulphur molar ratios on optical and electrical properties of nanostructural CuS thin films prepared by spray pyrolysis method  

Energy Technology Data Exchange (ETDEWEB)

Copper sulphide (CuS) thin films have been deposited on glass substrates by spray pyrolysis method using an aqueous solutions of copper (II) acetate and thiourea with different Cu to S molar ratios (0.33 and 0.43) at various substrate temperatures of 260, 285 and 310 Degree-Sign C. The structural, optical and electrical characterizations have been carried out using XRD, UV-Vis. transmittance/reflectance, PL spectra and Hall effect measurements. These characterizations indicated the formation of a CuS single phase (covellite) with polycrystalline nature with preferred orientation along (1 0 2) plane, except one with amorphous nature. Optical studies showed that the deposited layers have a relatively high absorption coefficient (5 Multiplication-Sign 10{sup 4} to 1 Multiplication-Sign 10{sup 5} cm{sup -1}) in the visible range, with an effective optical band gap of {approx}2.4-2.6 eV. The Hall effect data showed that all the grown samples have a degenerate p-type conductivity with a hole concentration of {approx}1.8 Multiplication-Sign 10{sup 20} to 1.7 Multiplication-Sign 10{sup 21} cm{sup -3}.

Adelifard, Mehdi [Department of Physics, Shahrood University of Technology, Shahrood 316-36155 (Iran, Islamic Republic of); Eshghi, Hosein, E-mail: h_eshghi@shahroodut.ac.ir [Department of Physics, Shahrood University of Technology, Shahrood 316-36155 (Iran, Islamic Republic of); Mohagheghi, Mohamad Mehdi Bagheri [School of Physics, Damghan University, Damghan (Iran, Islamic Republic of)

2012-05-15

222

Structural and optical properties of ZnO nanostructures grown by aerosol spray pyrolysis: Candidates for room temperature methane and hydrogen gas sensing  

International Nuclear Information System (INIS)

We report on the synthesis of ZnO films by aerosol spray pyrolysis method at different deposition times. The surface morphology, crystal structure and the cross-sectional analysis of the prepared ZnO films were characterized by X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), atomic force microscopy (AFM) and high resolution transmission electron microscopy (HR-TEM). XRD analysis revealed that the ZnO films are polycrystalline in nature. Structural analysis exploiting cross-sectional TEM profile showed that the films composed of nano-particles and columnar structures growing perpendicular to the substrate. AFM revealed that the columnar structures have a higher surface roughness as compared to the nanoparticles. The effect of ZnO crystallite size and crystallinity on the gas sensing performance of hydrogen and methane gases was also evaluated. Sensing film based on ZnO nanoparticles has numerous advantages in terms of its reliability and high sensitivity. These sensing materials revealed an improved response to methane and hydrogen gases at room temperature due to their high surface area, indicating their possible application as a gas sensor.

223

Orientation-dependent low field magnetic anomalies and room-temperature spintronic material Mn doped ZnO films by aerosol spray pyrolysis  

International Nuclear Information System (INIS)

Graphical abstract: Optical microscopy images of Mn doped ZnO films deposited for 20 min. Highlights: MnZnO films showing transparent spherical bubbles were synthesized by ASP. LFMA phenomenon was observed for these films. A relatively novel reversal magnetic feature to that of LFMA was observed. Ferromagnetic to paramagnetic transition due to Mn doping was observed. Angular dependence analysis showed evidence of magnetic anisotropy present. -- Abstract: High quality un-doped and Mn-doped ZnO films deposited by a simple aerosol spray pyrolysis technique for 20 and 30 min were studied using electron paramagnetic resonance (EPR), X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques. EPR analysis showed novel observation of low field microwave absorption (LFMA) on the manganese (Mn) doped zinc oxide (ZnO) films at various Mn concentrations. The results showed a peculiar behavior, reversal signal to that of LFMA. These findings also demonstrated that these films contain ferromagnetism at room temperature with possible applications in spintronics. Angular dependence measurements were found to induce magnetic transition from ferromagnetism to paramagnetism. Structural analysis showed that the undertaken materials are in wurtzite structures. The light absorption edge of MnZnO films red shifted which enhanced the observed ferromagnetism. The direct modulation of the band gap caused by MnZnO substitution is responsible for the red shift effect in absorption edge of ZnO

224

Effect of temperature on structural, optical and photoluminescence properties of antimony (Sb) doped polycrystalline CuInS2 thin films prepared by spray pyrolysis  

International Nuclear Information System (INIS)

Copper indium disulphide (CuInS2) is an absorber material for solar cell and photovoltaic applications. By suitably doping CuInS2 thin films with dopants such as Zn, Cd, Na, Bi, Sn, N, P and As its structural, optical, photoluminescence properties and electrical conductivities could be controlled and modified. In this work, Sb (0.01 mole (M)) doped CuInS2 thin films are grown in the temperature range 300-400 deg. C on heated glass substrates. It is observed that the film growth temperature, the ion ratio (Cu/In = 1.25) and Sb-doping affects the structural, optical and photoluminescence properties of sprayed CuInS2 films.The XRD patterns confirm that the Sb-doping suppresses the growth of CuInS2 polycrystalline thin films along (1 1 2) preferred plane and in other characteristic planes. The EDAX results confirm the presence of Cu, In, S and Sb. About 60% of light transmission occurs in the wavelength range 350-1100 nm. The absorption coefficient (?) is found to be in the order of 105 cm-1. The band gap energy increases as the temperature increases from 300-400 deg. C (1.35-1.40 eV). SEM photographs depict that large sized crystals of Sb-doped CuInS2 (1 ?m) are formed on the surface of the films. Well defined sharp blue and green band emissions are exhibited by Sb-doped CuInS2 thin films. Defects-related photoluminescence emissions are discussed. These Sb-doped CuInS2 thin films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of CuCl2, InCl3, SC(NH2)2 and SbCl3 on heated glass substrates.

225

PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST  

OpenAIRE

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...

Xian-Hua Wang; Han-Ping Chen; Xue-Jun Ding; Hai-Ping Yang; Shi-Hong Zhang; Ying-Qiang Shen

2009-01-01

226

Fast Pyrolysis of Lignin Using a Pyrolysis Centrifuge Reactor  

DEFF Research Database (Denmark)

Fast pyrolysis of lignin from an ethanol plant was investigated on a lab scale pyrolysis centrifuge reactor (PCR) with respect to pyrolysis temperature, reactor gas residence time, and feed rate. A maximal organic oil yield of 34 wt % dry basis (db) (bio-oil yield of 43 wt % db) is obtained at temperatures of 500?550 C, reactor gas residence time of 0.8 s, and feed rate of 5.6 g/min. Gas chromatography mass spectrometry and size-exclusion chromatography were used to characterize the Chemical properties of the lignin oils. Acetic acid, levoglucosan, guaiacol, syringols, and p-vinylguaiacol are found to be major chemical components in the lignin oil. The maximal yields of 0.62, 0.67, and 0.38 wt % db were obtained for syringol, p-vinylguaiacol, and guaiacol, respectively. The reactor temperature effect was investigated in a range of 450?600 C and has a considerable effect on the observed chemical components and molecular mass distribution of the lignin oils. The obtained lignin oil has a very different components composition when compared to a beech wood oil.

Trinh, Ngoc Trung; Jensen, Peter Arendt

2013-01-01

227

Rapid quantification of biomarkers during kerogen microscale pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

A rapid, reproducible method incorporating closed system microscale pyrolysis and thermal desorption-gas chromatography/mass spectrometry has been developed and applied to the quantification of sterane biomarkers released during pyrolysis of the Messel oil shale kerogen under confined conditions. This method allows a substantial experimental concentration-time data set to be collected at accurately controlled temperatures, due to the low thermal inertia of the microscale borosilicate glass reaction vessels, which facilitates kinetic studies of biomarker reactions during kerogen microscale pyrolysis

Stott, A.W.; Abbott, G.D. [Fossil Fuels and Environmental Geochemistry NRG, The University, Newcastle-upon-Tyne (United Kingdom)

1995-02-01

228

PRONOUNCED MUSCLE DEOXYGENATION DURING SUPRAMAXIMAL EXERCISE UNDER SIMULATED HYPOXIA IN SPRINT ATHLETES  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study was to determine whether acute hypoxia alters the deoxygenation level in vastus lateralis muscle during a 30 s Wingate test, and to compare the muscle deoxygenation level between sprint athletes and untrained men. Nine male track sprinters (athletic group, VO2max 62.5 4.1 ml/kg/min and 9 healthy untrained men (untrained group, VO2max 49.9 5.2 mlkg-1min-1 performed a 30 s Wingate test under simulated hypoxic (FIO2 = 0.164 and PIO2 = 114 mmHg and normoxic conditions. During the exercise, changes in oxygenated hemoglobin (OxyHb in the vastus lateralis were measured using near infrared continuous wave spectroscopy. Decline in OxyHb, that is muscle deoxygenation, was expressed as percent change from baseline. Percutaneous arterial oxygen saturation (SpO2, oxygen uptake (VO2, and ventilation (VE were measured continuously. In both groups, there was significantly greater muscle deoxygenation, lower SpO2, lower peakVO2, and higher peakVE during supramaximal exercise under hypoxia than under normoxia, but no differences in peak and mean power output during the exercise. Under hypoxia, the athletic group experienced significantly greater muscle deoxygenation, lower SpO2, greater decrement in peakVO2 and increment in peakVE during the exercise than the untrained group. When the athletic and untrained groups were pooled, the increment of muscle deoxygenation was strongly correlated with lowest SpO2 in the 30 s Wingate test under hypoxia. These results suggest that acute exposure to hypoxia causes a greater degree of peripheral muscle deoxygenation during supramaximal exercise, especially in sprint athletes, and this physiological response would be explained mainly by lower arterial oxygen saturation

Kazuo Oguri

2008-12-01

229

Fatigue life and crack growth mechanisms of the type 316LN austenitic stainless steel in 310degC deoxygenated water  

International Nuclear Information System (INIS)

The low cycle fatigue tests of the type 316LN stainless steel were conducted to investigate the cracking mechanisms in high-temperature water. The fatigue lives of the specimens tested in 310degC deoxygenated water were considerably shorter than those tested in air. For the specimens tested in 310degC deoxygenated water, the evidences for the metal dissolution such as the stream downed feature, the blunt crack shape, and the wider crack opening were observed but rather weakly. In the same specimens, the evidences for the hydrogen-induced cracking such as the coalescence of microvoids and the decrease of the dislocation spacing at the crack tip were observed rather clearly. Therefore, it is thought that the hydrogen-induced cracking is mainly responsible for the reduction in the fatigue life of the type 316LN stainless steel in 310degC deoxygenated water while the effect of metal dissolution is less significant. The hydrogen-induced cracking is more pronounced in the slower strain rates. This behavior is in accordance with the larger reduction in the fatigue life at the slower strain rates. Furthermore, the fatigue life and the dislocation spacing show the minimum value in the strain rate range from 0.008 to 0.04%/s, which indicates the existence of the critical strain rate. (author)

230

Pyrolysis and Gasification  

OpenAIRE

Pyrolysis and gasification include processes that thermally convert carbonaceous materials into products such as gas, char, coke, ash, and tar. Overall, pyrolysis generates products like gas, tar, and char, while gasification converts the carboncontaining materials (e.g. the outputs from pyrolysis) into a mainly gaseous output. The specific output composition and relative amounts of the outputs greatly depend on the input fuel and the overall process configuration. Although pyroly...

Astrup, Thomas; Bilitewski, B.

2010-01-01

231

Deoxygenation of glycolaldehyde and furfural on Mo2C/Mo(100)  

Science.gov (United States)

The desire to produce fuels and chemicals in an energy conscious, environmentally sympathetic approach has motivated considerable research on the use of cellulosic biomass feedstocks. One of the major challenges facing the utilization of biomass is finding effective catalysts for the efficient and selective removal of oxygen from the highly-oxygenated, biomass-derived platform molecules. Herein, a study of the reaction pathways for the biomass-derived platform molecule furfural and biomass-derived sugar model compound glycolaldehyde provides insight into the mechanisms of hydrodeoxygenation (HDO) on a model molybdenum carbide catalyst, Mo2C/Mo(100). Using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS), it was found that the Mo2C/Mo(100) catalyst was active for selective deoxygenation of the aldehyde carbonyl by facilitating adsorption of the aldehyde in an ?2(C,O) bonding configuration. Furthermore, the catalyst showed no appreciable activity for furanic ring hydrogenation, highlighting the promise of relatively inexpensive Mo2C catalysts for selective HDO chemistry.

McManus, Jesse R.; Vohs, John M.

2014-12-01

232

Deoxygenation in surface water of lotic environment (doi:10.4136/ambi-agua.127 (Portuguese  

Directory of Open Access Journals (Sweden)

Full Text Available The mathematical models are gaining increasing importance in the evaluation and comparison of alternative management of natural water bodies. One of the difficulties of using models of water quality for oxygen is the absence of data on kinetic parameters of reactions of biochemical processes. This study aimed to evaluate the processes of temporal processing of oxygen in surface water of lotic environment. The study was conducted in the Meia Ponte River, Gois, one of the main rivers of the state. Water samples were collected in the urban area of Goinia, Goinia New District 2, which shows apparent anthropogenic interference with the natural environment. After corrected to the standard temperature of 20C, the BOD varied between 4.11 and 21.24 mg L-1 and during the process of biological oxidation, the deoxygenation coefficient (Kd20 varied from 0.12 to 1.05 d- 1, and an increase of organic matter in the dry season was observed.

Eduardo Queija de Siqueira

2010-04-01

233

Pyrolysis of waste tyres: A review  

International Nuclear Information System (INIS)

Graphical abstract: - Highlights: Pyrolysis of waste tyres produces oil, gas and char, and recovered steel. Batch, screw kiln, rotary kiln, vacuum and fluidised-bed are main reactor types. Product yields are influenced by reactor type, temperature and heating rate. Pyrolysis oils are complex and can be used as chemical feedstock or fuel. Research into higher value products from the tyre pyrolysis process is reviewed. - Abstract: Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H2, C1C4 hydrocarbons, CO2, CO and H2S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale

234

Pyrolysis of waste tyres: A review  

Energy Technology Data Exchange (ETDEWEB)

Graphical abstract: - Highlights: Pyrolysis of waste tyres produces oil, gas and char, and recovered steel. Batch, screw kiln, rotary kiln, vacuum and fluidised-bed are main reactor types. Product yields are influenced by reactor type, temperature and heating rate. Pyrolysis oils are complex and can be used as chemical feedstock or fuel. Research into higher value products from the tyre pyrolysis process is reviewed. - Abstract: Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H{sub 2}, C{sub 1}C{sub 4} hydrocarbons, CO{sub 2}, CO and H{sub 2}S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale.

Williams, Paul T., E-mail: p.t.williams@leeds.ac.uk

2013-08-15

235

PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST  

Directory of Open Access Journals (Sweden)

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 600C.

Xian-Hua Wang

2009-08-01

236

Temperature dependant physical properties of CdIn2O4 thin films grown by spray pyrolysis  

Science.gov (United States)

Transparent conducting cadmium indium oxide films (CdIn2O4) were deposited on glass substrates at temperature of 350 and 400 C. The film structure and surface morphologies were investigated as a function of temperature by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The XRD results showed the single phase formation of the material that revealed the presence of Cd2+ and In3+ in the inverse spinel related structure. The chemical compositional analysis of CdIn2O4 films was carried out by X-ray photoelectron spectroscopy (XPS). Room temperature photoluminescence (PL) measurements indicate that the annealed CdIn2O4 thin film exhibit blue shift effect. The optical band gap of CdIn2O4 film was increased from 3.08 to 3.2 eV up to 400 C.

Deokate, R. J.

2014-12-01

237

CATALYTIC FAST PYROLYSIS OF CELLULOSE MIXED WITH SULFATED TITANIA TO PRODUCE LEVOGLUCOSENONE: ANALYTICAL PY-GC/MS STUDY  

OpenAIRE

Sulfated titania (SO42-/TiO2) was prepared and used for catalytic fast pyrolysis of cellulose to produce levoglucosenone (LGO), a valuable anhydrosugar product. Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) technique was employed in this study to achieve the catalytic fast pyrolysis of cellulose and on-line analysis of the pyrolysis vapors. Experiments were performed to investigate the effects of several factors on the LGO production, i.e. pyrolysis temperature, cellulo...

Qiang Lu; Xu-Ming Zhang,; Zhi-Bo Zhang; Ying Zhang; Xi-Feng Zhu,; Chang-Qing Dong

2012-01-01

238

Pyrolysis of rubber gloves in integral pyrolysis test plant  

International Nuclear Information System (INIS)

Previously, pyrolysis of rubber gloves in laboratory study was described. In order to visualize the practical application of rubber gloves pyrolysis in terms of treating rubber gloves in medical waste, a new test plant was designed and constructed. The semi-continuous test plant was designed to accommodate rubber gloves that were not cut or shredded. The test plant has a capacity of 2kg/ hr and employed auxiliary fuel instead of the conventional electrical power for heating. The concept was based on moving bed reactor, but additional feature of sand jacket feature was also introduced in the design. Pyrolysis of the gloves was conducted at three temperatures, namely 350 degree Celsius, 400 degree Celsius and 450 degree Celsius. Oxygen presents inside of the reactor due to the combined effect of imperfect sealing and suction effect. This study addresses the performance of this test plant covering the time temperature profile, gas evolution profile and product yield. Comparison between the yield of the liquid, gas and char pyrolyzate was made against the laboratory study. It was found that the oil yield was less than the one obtained from bench scale study. Water formation was more pronounced. The presence of the oxygen also altered the tail gas composition but eliminate the sticky nature of solid residue, making it easier to handle. The chemical composition of the oil was determined and the main compounds in the oil were esters and phtalic acid. (author)and phtalic acid. (author)

239

Stochastic state-space temperature regulation of biochar production Part II: Application to manure processing via pyrolysis  

Science.gov (United States)

BACKGROUND: The concept of a designer biochar that targets the improvement of a specific soil property imposes the need for production processes to generate biochars with both high consistency and quality. These important production parameters can be affected by variations in process temperature tha...

240

SIMULATION OF OLIVE PITS PYROLYSIS IN A ROTARY KILN PLANT  

Directory of Open Access Journals (Sweden)

Full Text Available This work deals with the simulation of an olive pits fed rotary kiln pyrolysis plant installed in Southern Italy. The pyrolysis process was simulated by commercial software CHEMCAD. The main component of the plant, the pyrolyzer, was modelled by a Plug Flow Reactor in accordance to the kinetic laws. Products distribution and the temperature profile was calculated along reactor's axis. Simulation results have been found to fit well the experimental data of pyrolysis. Moreover, sensitivity analyses were executed to investigate the effect of biomass moisture on the pyrolysis process.

Giacobbe Braccio

2011-01-01

241

Plasma pyrolysis of toxic waste  

Energy Technology Data Exchange (ETDEWEB)

The comparison of technical economic indexes of different waste treatment methods and plasma pyrolysis is presented in the paper. It testifies that plasma technologies are economically expedient for these purposes. Physical prerequisites allowing realizing plasma technologies are presented. Reliable and economical (70-120 Euro per ton of treated product) plasma generation is the basic condition of the technology realization. In this connection, various types of powerful generators of dense plasma (plasmatrons) in the range from 100 kW to 3 MW and temperature of plasma jets from 2000 to 10 000 K, and also physical processes taking place in electric-discharge chambers are examined. Differences between AC and DC electric arc plasma generators are analysed. Temperature in arcs of plasma generators varies from 6000 to 20,000 K, electron concentration is n{sub e} {approx} (10{sup 14}-10{sup 19} cm{sup -3}). Specific ware of electrodes in various types of plasma generators intended for long-time operation modes is (10{sup -7}-10{sup -4}) g C{sup -1}. Physicochemical processes in plasma reactors intended for waste treatment and pyrolysis are described. Different types of technological processes on plasma treatment and pyrolysis of waste are analysed. Estimation of present situation of physical investigations and technological developments in this area and predictions for nearest future are included.

Rutberg, Ph G [Institute of Problems of Electrophysics of Russian Academy of Sciences, 18 Dvortsovaya nab., St Petersburg, 191186 (Russian Federation)

2003-06-01

242

Plasma pyrolysis of toxic waste  

International Nuclear Information System (INIS)

The comparison of technical economic indexes of different waste treatment methods and plasma pyrolysis is presented in the paper. It testifies that plasma technologies are economically expedient for these purposes. Physical prerequisites allowing realizing plasma technologies are presented. Reliable and economical (70-120 Euro per ton of treated product) plasma generation is the basic condition of the technology realization. In this connection, various types of powerful generators of dense plasma (plasmatrons) in the range from 100 kW to 3 MW and temperature of plasma jets from 2000 to 10 000 K, and also physical processes taking place in electric-discharge chambers are examined. Differences between AC and DC electric arc plasma generators are analysed. Temperature in arcs of plasma generators varies from 6000 to 20,000 K, electron concentration is ne ? (1014-1019 cm-3). Specific ware of electrodes in various types of plasma generators intended for long-time operation modes is (10-7-10-4) g C-1. Physicochemical processes in plasma reactors intended for waste treatment and pyrolysis are described. Different types of technological processes on plasma treatment and pyrolysis of waste are analysed. Estimation of present situation of physical investigations and technological developments in this area and predictions for nearest future are included

243

Analyses of residual iron in carbon nanotubes produced by camphor/ferrocene pyrolysis and purified by high temperature annealing  

Energy Technology Data Exchange (ETDEWEB)

A detailed analysis of iron-containing phases in multiwall carbon nanotube (MWCNT) powder was carried out. The MWCNTs were produced by camphor/ferrocene and purified by high temperature annealing in an oxygen-free atmosphere (N{sub 2} or VC). Thermogravimetric analysis, Moessbauer spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy enabled the evaluation of the residual iron in MWCNTs after purification. The VC treatments provided MWCNTs with a purity degree higher than 99%. Moreover, Raman spectroscopy revealed a significant improvement in graphitic ordering after thermal annealing. A brief description of the mechanism of iron removal was included. We highlight the mobility of iron atoms through graphitic sheets and the large contact angle of iron clusters formed on MWCNT surfaces at high temperatures.

Antunes, E.F., E-mail: ericafa@las.inpe.br [Instituto Tecnologico de Aeronautica (ITA), Praca Marechal Eduardo Gomes, 50, CEP 12.228-900, Sao Jose dos Campos, SP (Brazil); Instituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas, 1758, CEP 12.227-010, Sao Jose dos Campos, SP (Brazil); Resende, V.G. de; Mengui, U.A. [Instituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas, 1758, CEP 12.227-010, Sao Jose dos Campos, SP (Brazil); Cunha, J.B.M. [Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Goncalves, 9500, CEP 91.501-970, Porto Alegre, RS (Brazil); Corat, E.J.; Massi, M. [Instituto Nacional de Pesquisas Espaciais (INPE), Av. dos Astronautas, 1758, CEP 12.227-010, Sao Jose dos Campos, SP (Brazil)

2011-07-01

244

Thermogravimetric Analysis and Global Kinetics of Segregated MSW Pyrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available Municipal Solid Wastes (MSW has great potential as a clean, renewable feedstock for producing modern energy carriers through thermochemical, called pyrolysis. However, despite their enormous potential as energy sources, their thermal characteristics are still not well known. Investigations about segregated MSW slow pyrolysis behaviors have done using macro balance apparatus. Four components of segregated MSW (bamboo wastes, banana leaves wastes, snack wrap wastes and styrofoam wastes and their bleds were thermally degraded through thermogravimetry analysis and their characteristics such as pyrolysis profiles and activation energies were analysed and calculated. About 20 grams of samples pyrolysed under 100 ml/min N2 at constant heating rate 10 0C/min from room temperature to 400 0C final pyrolysis temperature which kept constant for 30 minutes. The nitrogen flow as swept gas which ensures an inert atmosphere during the pyrolysis test.In order to indenty the pyrolysis characteristics of samples, thermogravimetry analysis performed. The recorded data were weight losses and sample temperature during the pyrolisis process. The results of the research showed bamboo wastes and banana leaves wastes could be catogorized as low stability organics, while snack wrap wastes could be catagorized as polymer mixture materials and styrofoam wastes could be catagorized as plastic materials.Meanwhile the blends materials pyrolysis profiles followed the their components characteristics which signed with the peak temperature which occured. This study also found that global kinetic method could to calculate the pyrolysis activation energy

Dwi Aries Himawanto

2011-12-01

245

Effect of temperature on structural, optical and photoluminescence properties of antimony (Sb) doped polycrystalline CuInS{sub 2} thin films prepared by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Copper indium disulphide (CuInS{sub 2}) is an absorber material for solar cell and photovoltaic applications. By suitably doping CuInS{sub 2} thin films with dopants such as Zn, Cd, Na, Bi, Sn, N, P and As its structural, optical, photoluminescence properties and electrical conductivities could be controlled and modified. In this work, Sb (0.01 mole (M)) doped CuInS{sub 2} thin films are grown in the temperature range 300-400 deg. C on heated glass substrates. It is observed that the film growth temperature, the ion ratio (Cu/In = 1.25) and Sb-doping affects the structural, optical and photoluminescence properties of sprayed CuInS{sub 2} films.The XRD patterns confirm that the Sb-doping suppresses the growth of CuInS{sub 2} polycrystalline thin films along (1 1 2) preferred plane and in other characteristic planes. The EDAX results confirm the presence of Cu, In, S and Sb. About 60% of light transmission occurs in the wavelength range 350-1100 nm. The absorption coefficient ({alpha}) is found to be in the order of 10{sup 5} cm{sup -1}. The band gap energy increases as the temperature increases from 300-400 deg. C (1.35-1.40 eV). SEM photographs depict that large sized crystals of Sb-doped CuInS{sub 2} (1 {mu}m) are formed on the surface of the films. Well defined sharp blue and green band emissions are exhibited by Sb-doped CuInS{sub 2} thin films. Defects-related photoluminescence emissions are discussed. These Sb-doped CuInS{sub 2} thin films are prepared by the cost effective method of spray pyrolysis from the aqueous solutions of CuCl{sub 2}, InCl{sub 3}, SC(NH{sub 2}){sub 2} and SbCl{sub 3} on heated glass substrates.

Suriyanarayanan, N., E-mail: madurasuri2210@yahoo.co.in [Department of Physics, Government College of Technology, Coimbatore 641 013, Tamil Nadu (India); Mahendran, C. [Department of Physics, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641 020, Tamil Nadu (India)

2011-03-25

246

STEPWISE ISOTHERMAL FAST PYROLYSIS (SIFP). PART II. SIFP OF PEANUT SHELLS - ANTIFUNGAL PROPERTIES OF PHENOLIC FRACTIONS  

OpenAIRE

Pyrolysis of peanut shells was carried out using stepwise isothermal fast pyrolysis (SIFP). SIFP consists of successive isothermal fast pyrolysis reactions, where solid products obtained in the previous isothermal fast pyrolysis become the substrate of the subsequent reaction at a higher temperature. This article reports results obtained from SIFP of peanut shells between 200 and 300C using 100C intervals under vacuum (0.2 mm). The maximum yield of liquid products was obtained at 300C, ...

Jorge Daniel Prez; Isasmendi, Guadalupe L.; Rosana Alarcn; Patricia Lpez Rivilli

2011-01-01

247

Simultaneous Recovery of Organic and Inorganic Content of Paper Deinking Residue through Low-Temperature Microwave-Assisted Pyrolysis.  

Science.gov (United States)

Significant amounts of paper deinking residue (DIR) has been and is still being generated from paper deinking processes, representing both an economic and environmental burden for recycled paper mills. Our research on low-temperature (change. The obtained liquid and solid products were characterized by a variety of analytical techniques (e.g., attenuated total reflection infrared, gas chromatography-mass spectrometry, liquid-state nuclear magnetic resonance (NMR), X-ray diffraction, solid-state cross-polarization/magic-angle spinning (13)C NMR, and Bloch-decay (13)C NMR). The results reveal that the process efficiently separates the inorganic minerals as microwave residue (mainly calcite and kaolinite) from organic matter, and hence the microwave residue could be reused to produce new paper/cardboard products. The organic fraction bio-oil generated is energy-densified and rich in carbohydrates and is a potential source for valuable aromatic compounds. PMID:25590264

Zhang, Zhanrong; Macquarrie, Duncan J; Aguiar, Pedro M; Clark, James H; Matharu, Avtar S

2015-02-17

248

Pyrolysis of Phenolic Impregnated Carbon Ablator (PICA).  

Science.gov (United States)

Molar yields of the pyrolysis products of thermal protection systems (TPSs) are needed in order to improve high fidelity material response models. The volatile chemical species evolved during the pyrolysis of a TPS composite, phenolic impregnated carbon ablator (PICA), have been probed in situ by mass spectrometry in the temperature range 100 to 935 C. The relative molar yields of the desorbing species as a function of temperature were derived by fitting the mass spectra, and the observed trends are interpreted in light of the results of earlier mechanistic studies on the pyrolysis of phenolic resins. The temperature-dependent product evolution was consistent with earlier descriptions of three stages of pyrolysis, with each stage corresponding to a temperature range. The two main products observed were H2O and CO, with their maximum yields occurring at ?350 C and ?450 C, respectively. Other significant products were CH4, CO2, and phenol and its methylated derivatives; these products tended to desorb concurrently with H2O and CO, over the range from about 200 to 600 C. H2 is presumed to be the main product, especially at the highest pyrolysis temperatures used, but the relative molar yield of H2 was not quantified. The observation of a much higher yield of CO than CH4 suggests the presence of significant hydroxyl group substitution on phenol prior to the synthesis of the phenolic resin used in PICA. The detection of CH4 in combination with the methylated derivatives of phenol suggests that the phenol also has some degree of methyl substitution. The methodology developed is suitable for real-time measurements of PICA pyrolysis and should lend itself well to the validation of nonequilibrium models whose aim is to simulate the response of TPS materials during atmospheric entry of spacecraft. PMID:25490209

Bessire, Brody K; Lahankar, Sridhar A; Minton, Timothy K

2015-01-28

249

Pyrolysis technologies for municipal solid waste: a review.  

Science.gov (United States)

Pyrolysis has been examined as an attractive alternative to incineration for municipal solid waste (MSW) disposal that allows energy and resource recovery; however, it has seldom been applied independently with the output of pyrolysis products as end products. This review addresses the state-of-the-art of MSW pyrolysis in regards to its technologies and reactors, products and environmental impacts. In this review, first, the influence of important operating parameters such as final temperature, heating rate (HR) and residence time in the reaction zone on the pyrolysis behaviours and products is reviewed; then the pyrolysis technologies and reactors adopted in literatures and scale-up plants are evaluated. Third, the yields and main properties of the pyrolytic products from individual MSW components, refuse-derived fuel (RDF) made from MSW, and MSW are summarised. In the fourth section, in addition to emissions from pyrolysis processes, such as HCl, SO2 and NH3, contaminants in the products, including PCDD/F and heavy metals, are also reviewed, and available measures for improving the environmental impacts of pyrolysis are surveyed. It can be concluded that the single pyrolysis process is an effective waste-to-energy convertor but is not a guaranteed clean solution for MSW disposal. Based on this information, the prospects of applying pyrolysis technologies to dealing with MSW are evaluated and suggested. PMID:25256662

Chen, Dezhen; Yin, Lijie; Wang, Huan; He, Pinjing

2014-12-01

250

Kinetics and Mechanism of Deoxygenation Reactions over Proton-Form and Molybdenum-Modified Zeolite Catalysts  

Science.gov (United States)

The depletion of fossil fuel resources and the environmental consequences of their use have dictated the development of new sources of energy that are both sustainable and economical. Biomass has emerged as a renewable carbon feedstock that can be used to produce chemicals and fuels traditionally obtained from petroleum. The oxygen content of biomass prohibits its use without modification because oxygenated hydrocarbons are non-volatile and have lower energy content. Chemical processes that eliminate oxygen and keep the carbon backbone intact are required for the development of biomass as a viable chemical feedstock. This dissertation reports on the kinetic and mechanistic studies conducted on high and low temperature catalytic processes for deoxygenation of biomass precursors to produce high-value chemicals and fuels. Low temperature, steady state reaction studies of acetic acid and ethanol were used to identify co-adsorbed acetic acid/ethanol dimers as surface intermediates within specific elementary steps involved in the esterification of acetic acid with ethanol on zeolites. A reaction mechanism involving two dominating surface species, an inactive ethanol dimeric species adsorbed on Bronsted sites inhibiting ester formation and a co-adsorbed complex of acetic acid and ethanol on the active site reacting to produce ethyl acetate, is shown to describe the reaction rate as a function of temperature (323 -- 383 K), acetic acid (0.5 -- 6.0 kPa), and ethanol (5.0 -- 13.0 kPa) partial pressure on proton-form BEA, FER, MFI, and MOR zeolites. Measured differences in rates as a function of zeolite structure and the rigorous interpretation of these differences in terms of esterification rate and equilibrium constants is presented to show that the intrinsic rate constant for the activation of the co-adsorbed complex increases in the order FER processing of acetic acid, formic acid, or carbon dioxide with methane (CH3COOH/CH4 = 0.04-0.10, HCOOH/CH 4 = 0.01-0.03, CO2/CH4 = 0.01-0.03) on Mo/H-ZSM-5 formulations at 950 K and atmospheric pressure in an effort to couple deoxygenation and dehydrogenation reaction sequences results instead in a two-zone, stratified bed reactor configuration consisting of upstream oxygenate/CH4 reforming and downstream CH4 dehydroaromatization. X-ray absorption spectroscopy and chemical transient experiments show that molybdenum carbide is formed inside zeolite micropores during CH4 reactions. The addition of an oxygenate co-feed causes oxidation of the active molybdenum carbide catalyst while producing CO and H2 until completely converted. Forward rates of C6H6 synthesis are unperturbed by the introduction of an oxygenate co-feed after rigorously accounting for the thermodynamic reversibility caused by the H2 produced in oxygenate reforming reactions and the fraction of the active catalyst deemed unavailable for CH 4 dehydroaromatization. All effects of co-processing C1-2 oxygenates and molecular H2 with CH4 can be interpreted in terms of an approach to equilibrium. Co-processing H2O, CO2, or light (C1-2, C/Heff processing larger (C 3-5, C/Heff ? 0.25) oxygenates with CH4 results in incomplete fragmentation of the co-fed oxygenate and preferential pathways of C6H6 synthesis that exclude CH4 incorporation. This results in greater net C6H6 synthesis rates than would be predicted from observations made when co-processing C1-2 oxygenates. Catalytic technologies have served a crucial role in processing petroleum feedstocks and are faced with new challenges as the feedstock shifts to chemically diverse but renewable biomass sources. This research addresses these challenges at fundamental and applied levels as it offers t

Bedard, Jeremy William

251

Pyrolysis of flame retardant brominated polyester composites.  

Science.gov (United States)

A series of three flame retardant, thermoset polyester/styrene composite wastes were pyrolysed in a static-bed reactor. The wastes contained different proportions of brominated polyester resin. Higher char and gas yields were observed on the pyrolysis of the brominated samples than for a similar non-brominated sample. The pyrolysis gas composition showed a small, but significant influence of pyrolysis temperature and by the use of brominated resin. In all cases, over 95wt % of the bromine originally present in the composite ended up in the condensable products. Thermo-gravimetric analysis indicated that the presence of brominated polyester resins decreased the temperatures at which the main decomposition region started and the maximum rate of weight loss was observed. The global apparent activation energy of decomposition was between 83 and 97kJ mol(-1). PMID:15691195

Cunliffe, A M; Williams, P T

2004-12-01

252

CATALYTIC THERMAL DECOMPOSITION OF POLYETHYLENE BY PYROLYSIS GAS CHROMATOGRAPHY  

OpenAIRE

An experimental study of the thermal decomposition of polyethylene in an inert atmosphere has been carried out in the temperature range 300-800C using Shimadzu PYR-2A pyrolyzer for heating the sample. The method allows the accurate control and measurement of the pyrolysis temperature. The production of hydrocarbons and the corresponding monomers of these polymeric systems were monitored. The effects of variation of temperature, sample size, pyrolysis atmosphere, residence time and catalyst ...

JAN NISAR; MUKHTIAR ALI; IFTIKHAR AHMAD AWAN

2011-01-01

253

Studies on characteristics of producer gas from sewage sludge pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis experiments of sewage sludge at low and middle temperature range from 250 C to 700de;C were carried out in a {phi} 200mm laboratory fixed bed external-heat reactor. The influence of final pyrolysis temperature on product yield of gases was studied. It was found that the gases yield increased with increasing the final pyrolysis temperature. But the productive rate increased above 450 C. The results indicated the secondary pyrolysis of intermediate product occurred about 450 C. According to the analysis of NCG, the yield of CO{sub 2} was maximum at lower pyrolysis temperature but the yields of H{sub 2}, CO, CH{sub 4} were higher at elevated pyrolysis temperature and the maximum caloric value of gaseous emissions were 16712 kJ/m{sup 3}. According the TG-DTA curves the decomposition of sewage sludge had three stages. The first stage was deprivation of interstitial moisture (100 C-110 C), the second stage was the depolymerization reactions of lipid and the generation of large molecular intermediate fragments (110 C-325 C), the last stage was cracking of the large molecular and the decomposition of protein and saccharide (325 C-600 C). All the results can offer reliable base data for the application of pyrolysis technique of sewage sludge. (orig.)

Li Haiying; Zhang Guijie [Coll. of Metallurgy and Energy, Heibei Polytechnic Univ., Tangshan (China); Zhang Shuting; Chen Guanyi [School of Environment Science and Technology, Tianjin Univ., Nankai District, TJ (China)

2008-07-01

254

Biomass pyrolysis for chemicals  

OpenAIRE

Biomass Pyrolysis for Chemicals The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for materials and energy where biomass provides the only renewable source for chemicals. In a biorefinery, biomass is converted via different technologies into heat, power and various products. Here, pyrolysis (thermal degradation without added oxygen) of lignocellulosic biomass can play an important role, because it leads to ...

Wild, Paul

2011-01-01

255

Pyrolysis of waste tyres: a review.  

Science.gov (United States)

Approximately 1.5 billion tyres are produced each year which will eventually enter the waste stream representing a major potential waste and environmental problem. However, there is growing interest in pyrolysis as a technology to treat tyres to produce valuable oil, char and gas products. The most common reactors used are fixed-bed (batch), screw kiln, rotary kiln, vacuum and fluidised-bed. The key influence on the product yield, and gas and oil composition, is the type of reactor used which in turn determines the temperature and heating rate. Tyre pyrolysis oil is chemically very complex containing aliphatic, aromatic, hetero-atom and polar fractions. The fuel characteristics of the tyre oil shows that it is similar to a gas oil or light fuel oil and has been successfully combusted in test furnaces and engines. The main gases produced from the pyrolysis of waste tyres are H(2), C(1)-C(4) hydrocarbons, CO(2), CO and H(2)S. Upgrading tyre pyrolysis products to high value products has concentrated on char upgrading to higher quality carbon black and to activated carbon. The use of catalysts to upgrade the oil to a aromatic-rich chemical feedstock or the production of hydrogen from waste tyres has also been reported. Examples of commercial and semi-commercial scale tyre pyrolysis systems show that small scale batch reactors and continuous rotary kiln reactors have been developed to commercial scale. PMID:23735607

Williams, Paul T

2013-08-01

256

Thermal pyrolysis products of poly-alpha-methylstyrene  

International Nuclear Information System (INIS)

An improved process for fabrication of hollow microspheres used as innertial confinement fusion targets is the decomposable mandrel technique. Thermal gravity analysis and pyrolysis gas chromatorgraph/mass spectrometry were applied to obtaining the thermal pyrolysis behavior of poly-alpha-methylstyrene with weight-average relative molecular mass of 1.14 x 106. Ex- periment indicated that the pyrolysis temperature of poly-alpha-methylstyrene covered from 260 degree C to 320 degree C, and that of glow discharge polymer covered from 350 degree C to 420 degree C. Poly-alpha-methylstyrene degraded mostly to its monomer, alpha-methylstyrene. Tetrahydrofuran and alpha-methylstyrene dimer were found in the pyrolysis products. Tetrahydrofuran was the solvent used in preparation of poly-alpha-methylstyrene. The mass fraction of monomers was more than 99% among the pyrolysis products. (authors)

257

Syngas yield during pyrolysis and steam gasification of paper  

International Nuclear Information System (INIS)

Main characteristics of gaseous yield from steam gasification have been investigated experimentally. Results of steam gasification have been compared to that of pyrolysis. The temperature range investigated were 600-1000 C in steps of 100 C. Results have been obtained under pyrolysis conditions at same temperatures. For steam gasification runs, steam flow rate was kept constant at 8.0 g/min. Investigated characteristics were evolution of syngas flow rate with time, hydrogen flow rate and chemical composition of syngas, energy yield and apparent thermal efficiency. Residuals from both processes were quantified and compared as well. Material destruction, hydrogen yield and energy yield is better with gasification as compared to pyrolysis. This advantage of the gasification process is attributed mainly to char gasification process. Char gasification is found to be more sensitive to the reactor temperature than pyrolysis. Pyrolysis can start at low temperatures of 400 C; however char gasification starts at 700 C. A partial overlap between gasification and pyrolysis exists and is presented here. This partial overlap increases with increase in temperature. As an example, at reactor temperature 800 C this overlap represents around 27% of the char gasification process and almost 95% at reactor temperature 1000 C.

258

Preparation of solid nickel nanoparticles by large-scale spray pyrolysis of Ni(NO3)2.6H2O precursor: Effect of temperature and nickel acetate on the particle morphology  

International Nuclear Information System (INIS)

Spherical nickel nanoparticles were prepared by a large-scale spray pyrolysis process with two continuous reactors and were investigated in terms of particle-formation mechanism, surface property, particle shape, and size with changing the temperature of two continuous reactors and the type of precursor. When nickel nitrate was used as a precursor and the second reactor temperature was over 1200 deg. C, solid Ni particles were obtained, but many ultra-fine particles of less than tens nanometer were simultaneously formed via a gas-to-particle conversion mechanism. The formation of such ultra-fine particles was reduced by making hollow particles in the first reactor at 500 deg. C and thereafter densifying them in the second reactor at 1400 deg. C, but could not completely prevent. The addition of about 5-10 mol% nickel acetate instead nitrate precursor was found to be very effective to avoid the formation of such ultra-fine particles as well as producing solid particles with clean and smooth surface. On the basis of the results obtained, a mechanism of particle formation in the large-scale spray pyrolysis was proposed. Finally, spherical and solid nickel nanoparticles, which had clean surface and high density (larger than 8.4 g/cm3), were prepared from the mixed precursor (nitrate/acetate) at a residence time of about 3 s without any chemical additive

259

Comparison of products from the pyrolysis and catalytic pyrolysis of rice husks  

Energy Technology Data Exchange (ETDEWEB)

Rice husks were pyrolysed in a fluidised bed reactor at 400, 450, 500, 550 and 600{sup o}C. The rice husks were then pyrolysed at 550{sup o}C with zeolite ZSM-5 catalyst upgrading of the pyrolysis vapours at catalyst temperatures of 400, 450, 500, 550, and 600{sup o}C. The pyrolysis oils were collected in a series of condensers and cold traps and analysed to determine their yield and composition in relation to process conditions. The gases were analysed off-line by packed column gas chromatography. The pyrolysis oils before catalysis were homogeneous, of low viscosity and highly oxygenated. Polycyclic aromatic hydrocarbons (PAH) were present in the oils at low concentration and increased in concentration with increasing temperature of pyrolysis. Oxygenated compounds in the oils consisted mainly of phenols, cresols, benzenediols and guaiacol and their alkylated derivatives. In the presence of the catalyst the yield of oil was markedly reduced, although the oxygen content of the oil was reduced with the formation of coke on the catalyst. The influence of the catalyst was to convert the oxygen,in the pyrolysis oil to largely H{sub 2}O at the lower catalyst temperatures and to largely CO and CO{sub 2} at the higher catalyst temperatures. The molecular weight distribution of the oils was decreased after catalysis and further decreased with increasing temperature of catalysis. The catalysed oils were markedly increased in single ring and PAH compared to uncatalysed biomass pyrolysis oils. The concentration of aromatic and polycyclic aromatic species increased with increasing catalyst temperature. (author)

Williams, P.T.; Nugranad, N. [University of Leeds (United Kingdom). Dept. of Fuel and Energy

2000-06-01

260

Scintillation decay time and pulse shape discrimination in oxygenated and deoxygenated solutions of linear alkylbenzene for the SNO+ experiment  

Science.gov (United States)

The SNO+ liquid scintillator experiment is under construction in the SNOLAB facility in Canada. The success of this experiment relies upon accurate characterization of the liquid scintillator, linear alkylbenzene (LAB). In this paper, scintillation decay times for alpha and electron excitations in LAB with 2 g/L PPO are presented for both oxygenated and deoxygenated solutions. While deoxygenation is expected to improve pulse shape discrimination in liquid scintillators, it is not commonly demonstrated in the literature. This paper shows that for linear alkylbenzene, deoxygenation improves discrimination between electron and alpha excitations in the scintillator.

O'Keeffe, H. M.; O'Sullivan, E.; Chen, M. C.

2011-06-01

261

Scintillation decay time and pulse shape discrimination in oxygenated and deoxygenated solutions of linear alkylbenzene for the SNO+ experiment  

CERN Document Server

The SNO+ liquid scintillator experiment is under construction in the SNOLAB facility in Canada. The success of this experiment relies upon accurate characterization of the liquid scintillator, linear alkylbenzene (LAB). In this paper, scintillation decay times for alpha and electron excitations in LAB with 2 g/L PPO are presented for both oxygenated and deoxygenated solutions. While deoxygenation is expected to improve pulse shape discrimination in liquid scintillators, it is not commonly demonstrated in the literature. This paper shows that for linear alkylbenzene, deoxygenation improves discrimination between electron and alpha excitations in the scintillator.

O'Keeffe, H M; Chen, M C

2011-01-01

262

Scintillation decay time and pulse shape discrimination in oxygenated and deoxygenated solutions of linear alkylbenzene for the SNO+ experiment  

International Nuclear Information System (INIS)

The SNO+ liquid scintillator experiment is under construction in the SNOLAB facility in Canada. The success of this experiment relies upon accurate characterization of the liquid scintillator, linear alkylbenzene (LAB). In this paper, scintillation decay times for alpha and electron excitations in LAB with 2 g/L PPO are presented for both oxygenated and deoxygenated solutions. While deoxygenation is expected to improve pulse shape discrimination in liquid scintillators, it is not commonly demonstrated in the literature. This paper shows that for linear alkylbenzene, deoxygenation improves discrimination between electron and alpha excitations in the scintillator.

263

Plasma emission spectral detection for pyrolysis-gas chromatography  

Science.gov (United States)

Specific element gas chromatographic detection by plasma emission spectroscopy has been evaluated for the characterization of volatile pyrolyzates from a number of polymers containing hetero-atoms. Directly interfaced rapid-temperature rise time pyrolysis with high resolution open tubular column gas chromatography was employed. The atmospheric pressure microwave induced and sustained plasma utilizing a "Beenakker" type TM 010 cavity was applied for specific detection of phosphorus and carbon in polyphosphazene pyrolysis and for boron in carborane-silicone pyrolysis. An interfaced d.c. argon atmospheric pressure plasma was found more advantageous for the specific determination of silicon in the pyrolysis products of novel linear silarylene-siloxanes. In phosphazene pyrolysis notable differences were seen in the phosphorus content of volatiles formed on pyrolysis between polymers fluoroalkoxy and chlorophenoxy substituents. For carborane-silicones sequential volatilization followed by pyrolysis allowed the identification of residual boron containing monomers as well as pyrolyzates. Pyrolysis of the silarylene-siloxanes showed markedly differing levels of silicon content in polymers with differing aromatic backbones and different levels of vinyl substitution.

Riska, Gregory D.; Estes, Scott A.; Beyer, John O.; Uden, Peter C.

264

Microwave-assisted pyrolysis of biomass for liquid biofuels production  

DEFF Research Database (Denmark)

Production of 2nd-generation biofuels from biomass residues and waste feedstock is gaining great concerns worldwide. Pyrolysis, a thermochemical conversion process involving rapid heating of feedstock under oxygen-absent condition to moderate temperature and rapid quenching of intermediate products, is an attractive way for bio-oil production. Various efforts have been made to improve pyrolysis process towards higher yield and quality of liquid biofuels and better energy efficiency. Microwave-assisted pyrolysis is one of the promising attempts, mainly due to efficient heating of feedstock by microwave dielectric heating effects. This paper presents a state-of-the-art review of microwave-assisted pyrolysis of biomass. First, conventional fast pyrolysis and microwave dielectric heating is briefly introduced. Then microwave-assisted pyrolysis process is thoroughly discussed stepwise from biomass pretreatment to bio-oil collection. The existing efforts are summarized in a table, providing a handy overview of the activities (e.g., feedstock and pretreatment, reactor/pyrolysis conditions) and findings (e.g., pyrolysis products) of various investigations.

Yin, Chungen

2012-01-01

265

Production, characterization and reactivity studies of chars produced by the isothermal pyrolysis of flax straw  

International Nuclear Information System (INIS)

The influence of pyrolysis temperature and residence time on the char yields and resultant char characteristics were investigated in the isothermal pyrolysis of flax straw. The pyrolysis temperature was varied in the range between 300 and 500 C and reaction residence time was varied from 15 to 60 min. The char yield was found to decrease with both increasing pyrolysis temperature and residence time. The char structure and physical characteristics were thoroughly investigated by means of X-ray diffraction (XRD), temperature-programmed oxidation (TPO) and N2 physisorption techniques. The results show that the degree of porosity and graphitization increased with increasing pyrolysis temperature and time. TPO studies on the char samples corroborate well with the XRD findings and showed the presence of two types of carbon; namely, amorphous filamentous carbon and crystalline graphitic carbon. Thermogravimetric analysis (TGA) of the char was performed to understand the combustion kinetics and reactivity. Chars formed at lower pyrolysis temperatures were found to be more reactive than the chars produced at higher pyrolysis temperatures, and these findings are well supported by the TPO, TGA, N2 physisorption and XRD characterization data. Furthermore, an empirical global kinetic model was devised based on power law and used to estimate the activation energy and other kinetic parameters of both flax straw pyrolysis and char combustion processes. -- Highlights: ? The results show conditions to obtain reactive chars from pyrolysis of flax straw. ? A higher pyrolysis temperature leads to a higher amount of nonreactive chars. ? A longer reaction time leads to a higher amount of nonreactive chars. ? A lower pyrolysis temperature and a shorter residence time lead to reactive chars. ? Pyrolysis temperature has a stronger effect on char reactivity than residence time.

266

Electrocatalytic upgrading of biomass pyrolysis oils to chemical and fuel  

Science.gov (United States)

The present project's aim is to liquefy biomass through fast pyrolysis and then upgrade the resulting "bio-oil" to renewable fuels and chemicals by intensifying its energy content using electricity. This choice reflects three points: (a) Liquid hydrocarbons are and will long be the most practical fuels and chemical feedstocks because of their energy density (both mass and volume basis), their stability and relative ease of handling, and the well-established infrastructure for their processing, distribution and use; (b) In the U.S., the total carbon content of annually harvestable, non-food biomass is significantly less than that in a year's petroleum usage, so retention of plant-captured carbon is a priority; and (c) Modern technologies for conversion of sunlight into usable energy forms---specifically, electrical power---are already an order of magnitude more efficient than plants are at storing solar energy in chemical form. Biomass fast pyrolysis (BFP) generates flammable gases, char, and "bio-oil", a viscous, corrosive, and highly oxygenated liquid consisting of large amounts of acetic acid and water together with hundreds of other organic compounds. With essentially the same energy density as biomass and a tendency to polymerize, this material cannot practically be stored or transported long distances. It must be upgraded by dehydration, deoxygenation, and hydrogenation to make it both chemically and energetically compatible with modern vehicles and fuels. Thus, this project seeks to develop low cost, general, scalable, robust electrocatalytic methods for reduction of bio-oil into fuels and chemicals.

Lam, Chun Ho

267

CATALYTIC THERMAL DECOMPOSITION OF POLYETHYLENE BY PYROLYSIS GAS CHROMATOGRAPHY  

Scientific Electronic Library Online (English)

Full Text Available An experimental study of the thermal decomposition of polyethylene in an inert atmosphere has been carried out in the temperature range 300-800C using Shimadzu PYR-2A pyrolyzer for heating the sample. The method allows the accurate control and measurement of the pyrolysis temperature. The productio [...] n of hydrocarbons and the corresponding monomers of these polymeric systems were monitored. The effects of variation of temperature, sample size, pyrolysis atmosphere, residence time and catalyst on the distribution of these products were studied. As the carrier gas rapidly swept the primary products from the hot zone into the chromatographic column, so the secondary decomposition is largely eliminated and the pyrolysis products give accurate information about the nature, composition and structure of the pyrolysis material.

JAN, NISAR; MUKHTIAR, ALI; IFTIKHAR, AHMAD AWAN.

268

Pulse radiolysis of 1,2-di(?-naphthyl)ethane in deoxygenated methanol and tetrahydrofuran  

International Nuclear Information System (INIS)

Pulse radiolysis of 1,2-di(?-naphthyl)ethane (1,2-DNE) was performed in deoxygenated pure methanol and tetrahydrofuran (THF). Absorption spectra and kinetics of 1,2-DNE- in both solvents are presented. In methanol 1,2-DNE- is formed and decays by a second order reaction. No cleavage of benzylic C-C bond occurs as has been observed in the presence of alkali metals in ethers. Hence, it can be concluded that the assistance of the metal cations is necessary for the reductive bond splitting process. For comparison, 1-bromomethylnaphthalene (Br-MN) and 1,2-diphenylethane (1,2-DPE) were investigated in deoxygenated methanol and results are given. Probable reaction mechanisms are presented. (author)

269

Radical mediated deoxygenation of inositol benzylidene acetals: conformational analysis, DFT calculations, and mechanism.  

Science.gov (United States)

Xanthates of 1,3-benzylidene acetal derivatives of myo- and neo-inositols undergo dideoxygenation under Barton-McCombie conditions, as a result of intramolecular abstraction of the benzylidene acetal hydrogen and subsequent cleavage of the acetal ring. Scrutiny of structure of these bicyclic inositol derivatives shows that although the conformation of the two rings can vary depending on the configuration of the inositol ring and the phase in which the molecules are present, both the xanthates lead to the formation of the same dideoxyinositol. DFT calculations on these molecular systems suggest that neo-inositol derivatives undergo conformational change prior to radical formation while myo-inositol derivatives undergo conformational change subsequent to radical formation, during the deoxygenation reaction. A low barrier for intramolecular hydrogen transfer supports the extreme facility of this deoxygenation reaction. PMID:22316428

Gurale, Bharat P; Vanka, Kumar; Shashidhar, Mysore S

2012-04-01

270

Spatially variable deoxygenation in the Danshui River: improvement in model calibration.  

Science.gov (United States)

A modeling study of the Danshui River, Taiwan, reveals that in-stream BOD deoxygenation rates vary significantly along the river as a result of the highly variable strength of wastewater discharges, which directly reflect the effluent characteristics. A comprehensive field data gathering and lab analysis effort for the study site is presented. Results of the data analyses yielded spatially variable CBOD deoxygenation and nitrification rates, which were incorporated in a model of the river. The model results indicate significant improvement of model calibration, thus enhancing the predictive capability of the model for its use in water quality management. To maximize the benefits of pollution control for the Danshui River system and to achieve the water quality management goal, concurrent reductions of CBOD and ammonia loads, instead of phased reduction of CBOD followed by ammonia reduction, are strongly recommended by the model results. PMID:24597040

Chen, Chien-Hung; Lung, Wu-Seng; Yang, Chung-Han; Lin, Cheng-Fang

2013-12-01

271

PYROLYSIS AND COMBUSTION OF SCRAP TIRE  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper a literature review of both pyrolysis and combustion processes of scrap tires is presented. The work reports, the characteristics of materials, methods, effect of various process parameters, kinetic modelling applied to the pyrolysis and combustion of tires, characteristics of the products and emissions. From the published works results that scrap tire rubber consists of about 60 wt.% volatile organics, 30 wt.% fixed carbon and 10 wt.% ash. Elemental analysis shows that tire rubber contains approximately 80 wt.% of C, 7 wt. of H, 0.4 wt.% of N, 1.5 wt.% of S, 3 wt.% of O and 8 wt.% of ash. Thermogravimetry analysis reveals that the pyrolysis of tire rubber at atmospheric pressure starts at a temperature around 250oC and finishes at a temperature of about 550oC. Generally, more than one degradation temperature region during rubber pyrolysis is recorded. In general, by pyrolysing waste tire three fractions are obtained: solid residue (around 40 wt.%, liquid fraction (around 50 wt.% and gas fraction (around 10 wt.%. The influence of the process conditions on the amount and characteristics of individual fractions was studied by the authors only partially. The general trend is an increase in yields of liquid and gas fractions as the temperature increases. From the works devoted to tire pyrolysis, which are focussed on the generation of liquid fuel results that derived liquids are a complex mixture of organic compounds containing a lot of aromatics. This liquid can be separated into light and higher fractions. The main components of pyrolysis gases reported by various authors are as: H2, H2S, CO, CO2, CH4, C2H4, C3H6 and other light hydrocarbons. The solid residue contains carbon black, and inorganic matter. The results of kinetic modelling of scrap tire pyrolysis and combustion show large differences in the values of kinetic parameters obtained by different authors. As main pollutants from the combustion of waste tires are reported: SO2, NOx, CO and PAHs.

?. Jelemensk

2006-02-01

272

Scintillation decay time and pulse shape discrimination in oxygenated and deoxygenated solutions of linear alkylbenzene for the SNO+ experiment  

OpenAIRE

The SNO liquid scintillator experiment is under construction in the SNOLAB facility in Canada. The success of this experiment relies upon accurate characterization of the liquid scintillator, linear alkylbenzene (LAB). In this paper, scintillation decay times for alpha and electron excitations in LAB with 2 g/L PPO are presented for both oxygenated and deoxygenated solutions. While deoxygenation is expected to improve pulse shape discrimination in liquid scintillators, it is not commonly demo...

O Keeffe, Hm; O Sullivan, E.; Chen, Mc

2011-01-01

273

Pyrolysis and Gasification  

DEFF Research Database (Denmark)

Pyrolysis and gasification include processes that thermally convert carbonaceous materials into products such as gas, char, coke, ash, and tar. Overall, pyrolysis generates products like gas, tar, and char, while gasification converts the carboncontaining materials (e.g. the outputs from pyrolysis) into a mainly gaseous output. The specific output composition and relative amounts of the outputs greatly depend on the input fuel and the overall process configuration. Although pyrolysis processes in many cases also occur in gasification (however prior to the gasification processes), the overall technology may often be described as gasification only. Pyrolysis, however, can also be employed without proceeding with gasification. Gasification is by no means a novel process; in the 19th century so-called town gas was produced by the gasification of coal and for example used for illumination purposes. In Europe during World War II, wood-fueled gasifiers (or gas generators) were used to power cars during shortagesof oil-based fuels. Sparked by oil price crises in 1970s and 1980s, further development in gasification technologies focused mainly on coal as a fuel to substitute for oil-based products. Today gasification is used within a range of applications, the most important of which are conversion of coal into syngas for use as chemical feedstock or energy production; but also gasification of biomass and waste is gaining significant interest as emerging technologies for sustainable energy. From a waste management perspective, pyrolysis and gasification are of relatively little importance as an overall management option. Today, gasification is primarily used on specific waste fractions as opposed to mixed household wastes. The main commercial activity so far has been in Japan, with only limited success in Europe and North America (Klein et al., 2004). However, pyrolysis and gasification of waste are generally expected to become more widely used in the future. A main reason for this is that public perceptions of waste incineration in some countries is a major obstacle for installing new incineration capacity, but also a better ability of gasification over incineration to preserve the chemical energy of the waste is important. This chapter provides an overview of pyrolysis and gasification processes related to waste, the technology involved, energy recovery options, and important environmental aspects.

Astrup, Thomas; Bilitewski, B.

2011-01-01

274

Co-pyrolysis of polypropylene waste with Brazilian heavy oil.  

Science.gov (United States)

To evaluate the chemical recycling of plastic residues, co-pyrolysis of polypropylene (PP) waste with Brazilian crude oil was evaluated varying the temperature (400C to 500C) and the amount of PP fed to the reactor. The co-pyrolysis of plastic waste in an inert atmosphere provided around 80% of oil pyrolytic, and of these, half represent the fraction of diesel oil. This study can be used as a reference in chemical recycling of plastics, specially associated with plastics co-pyrolysis. PMID:21409698

Assumpo, Luiz C F N; Carbonell, Montserrat M; Marques, Mnica R C

2011-01-01

275

Microwave pyrolysis of microalgae for high syngas production  

OpenAIRE

[EN]The microwave induced pyrolysis of the microalga Scenedesmus almeriensis and its extraction residue was carried out at 400 and 800 C. The results show that it is possible to obtain a gas fraction with a high content (c.a. 50 vol.%) in H2 from both materials, regardless of the pyrolysis temperature. Furthermore, an outstanding syngas production and high gas yields were achieved. The maximum syngas concentration obtained was c.a. 94 vol.%, in the case of the pyrolysis of th...

Beneroso Vallejo, Daniel; Bermu?dez Mene?ndez, Jose? Miguel; Arenillas La Puente, Ana; Mene?ndez Di?az, Jose? A?ngel

2013-01-01

276

Pyrolysis and hydrolysis of mixed polymer waste comprising polyethyleneterephthalate and polyethylene to sequentially recover  

Science.gov (United States)

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent.

Evans, Robert J. (Lakewood, CO); Chum, Helena L. (Arvada, CO)

1998-01-01

277

Determination of the Deoxygenation Rates of a Residential Institution`s Wastewater  

Directory of Open Access Journals (Sweden)

Full Text Available Empirical analysis of a residential institution`s wastewater (WW for the design parameters such as carbonaceous deoxygenation rate (K and nitrogenous deoxygenation (or nitrification rate was reported in this study. Standard laboratory procedures were used in analysing the microbial activities in incubated samples in terms of dissolved oxygen requirements for carbonaceous deoxygenation and nitrification using both the daily difference method and the dimension less Fibonacci technique respectively. The BOD removal rate for Obafemi Awolowo University, Ile-Ife`s residential institutional waste was found to be 0.23/day with standard deviation of 0.036 day. Mean of the ultimate BOD of the WW was found to be 631.2 mg L-1. Likewise, the nitrification rates were found to be in the range of 0.293-0.443 day with a mean value of 0.34 day. The results show that institutional WWs are stronger than domestic WWs but less strong than some industrial waste waters such as tannery WW.

I. Adewumi

2005-01-01

278

Flash pyrolysis of jatropha oil cake in electrically heated fluidized bed reactor  

International Nuclear Information System (INIS)

Fluidized bed flash pyrolysis experiments have been conducted on a sample of jatropha oil cake to determine particularly the effects of particle size, pyrolysis temperature and nitrogen gas flow rate on the pyrolysis yields. The particle size, nitrogen gas flow rate and temperature of jatropha oil cake were varied from 0.3 to 1.18 mm, 1.25 to 2.4 m3/h and 350 to 550 oC. The maximum oil yield of 64.25 wt% was obtained at a nitrogen gas flow rate of 1.75 m3/h, particle size of 0.7-1.0 mm and pyrolysis temperature of 500 oC. The calorific value of pyrolysis oil was found to be 19.66 MJ/kg. The pyrolysis gas can be used as a gaseous fuel.

279

ENGINEERING BULLETIN: PYROLYSIS TREATMENT  

Science.gov (United States)

Pyrolysis is formally defined as chemical decomposition induced in organic materials by heat in the absence of oxygen. In practice, it is not possible to achieve a completely oxygen-free atmosphere; actual pyrolytic systems are operated with less than stoichiometric quantities of...

280

Slow Pyrolysis of Cassava Wastes for Biochar Production and Characterization  

OpenAIRE

Production of biochar from slow pyrolysis of biomass is a promising carbon negative procedure since it removes the net carbon dioxide in the atmosphere and produce recalcitrant carbon suitable for sequestration in soil. Biochar production can vary significantly with the pyrolysis parameter. This study investigated the impact of temperature and heating rate on the yield and properties of biochar derived from cassava plantations residues which are cassava stem (CS) and cassava rhizome (CR). The...

Nurhidayah Mohamed Noor; Adilah Shariff; Nurhayati Abdullah

2012-01-01

281

Thermal decomposition of polystyrene by pyrolysis gas chromatography  

International Nuclear Information System (INIS)

Pyrolysis GC method has been applied to investigate the structure and composition of polystyrene and the plastic wastes based on this polymer. The production of hydrocarbons and monomer of this polymeric system was monitored. The effect of variation of temperature (300-800 deg. C) sample size (1-10 mg), pyrolysis atmosphere (Nitrogen and Helium), residence tie (0.365-1.218 seconds) and catalyst (alumina, silica gel and zeolite) on the distribution of these prodicts were studied. (author)

282

Environmental fatigue behaviors of wrought and cast stainless steels in 310 .deg. C Deoxygenated Water  

Energy Technology Data Exchange (ETDEWEB)

Environmental fatigue behaviors of wrought type 316LN stainless steel and cast CF8M stainless steel were investigated. LCF tests were performed at fixed strain rate of 0.04%/s with 0.4%, 0.6%, 0.8%, 1.0% strain amplitudes in 310 .deg. C deoxygenated water environment. In addition, to analyze microstructure effect on fatigue behavior, low cycle fatigue tests in air environment were performed at fixed strain rate of 0.4%/s, 0.04%/s with 0.4%, 0.8% strain amplitudes. It was shown that the low cycle fatigue life of CF8M in a 310 .deg. C deoxygenated water environment was slightly longer than that of 316LN. On the other hand, the low cycle fatigue life of CF8M in a 310 .deg. C air environment was slightly shorter than that of 316LN or was similar with that of 316LN. Through OM observation and phase image analysis, it was confirmed that the ferrite content of CF8M tested in a 310 .deg. C deoxygenated water environment was larger than that of CF8M tested in a 310 .deg. C air environment. It was shown that the ferrite phase fraction of CF8M tested in 310 .deg. C deoxygenated water environment was approximately 26?28% and that of CF8M tested in air environment was approximately 10?12%. The difference of ferrite content in CF8M results in superior tensile properties as higher ferrite content. Furthermore, the difference of ferrite content in CF8M might be the cause of different result of fatigue life between CF8M and 316LN depending on environment. In this study, focused on CF8M having 26?28% ferrite content, to understand the causes of these differences in a 310 .deg. C deoxygenated water environment, fracture surface and crack morphology were observed. And material factors like microstructure, mechanical properties factors like stress behavior during fatigue life, factors by environmentally assisted cracking (EAC) like hydrogen induced cracking (HIC) and chemical compositions of both materials were analyzed. Mainly in a 310 .deg. C deoxygenated water environment, the analysis of fatigue surface was conducted at 1.0% strain amplitude, the analysis of crack sectioned area was conducted at 0.8% strain amplitude. Mainly in air environment, the analysis of fatigue surface was conducted at 0.4% strain amplitude. Through this study and analysis, it was thought that low cycle fatigue crack growth rate of CF8M would be affected by relative contribution of both barrier role of ferrite phase and acceleration role of crack linkage phenomenon or HIC. In low cycle fatigue operating relatively higher stress, it was known that the crack generally tend to avoid and propagate around hard phase. Like the preceding, this test results indicated that the barrier role such as crack avoiding is slightly greater than acceleration role such as crack linkage added HIC mechanism, resulting in slower fatigue crack growth rate by consumption of excess energy, or longer LCF lives in cast CF8M than wrought type 316LN in 310 .deg. C deoxygenated water.

Cho, Pyung Yeon

2011-02-15

283

Solid waste utilization: pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

As a part of the Integrated Community Energy System (ICES) Program, a number of technology evaluations are being prepared on various current and emerging sources of energy. This evaluation considers the use of pyrolysis as a method of producing energy from municipal solid waste. The energy can be in the form of a gas, oil, chars, or steam. Pyrolysis, the decomposition of organic matter in the absence of oxygen (or in an oxygen-deficient atmosphere), has been used to convert organic matter to other products or fuels. This process is also described as ''destructive distillation''. Four processes are described in detail: the ''Landgard'' System (Monsanto Environ-Chem Systems, Inc.); the Occidental Research Corporation Process (formerly the Garrett Research and Development Company; The ''Purox'' System (Union Carbide Corporation); and the ''Refu-Cycler'' (Hamilton Standard Corporation). ''Purox'' and ''Refu-Cycler'' produce a low-Btu gas; the Occidental process produces an oil, and the ''Landgard'' process produces steam using on-site auxiliary boilers to burn the fuel gases produced by the pyrolysis unit. Also included is a listing of other pyrolysis processes currently under development for which detailed information was not available. The evaluation provides information on the various process flowsheets, energy and material balances, product characteristics, and economics. Pyrolysis of municipal solid waste as an energy source can be considered a potential for the future; however little operational or economic information is available at this time.

Boegly, W.J. Jr.; Mixon, W.R.; Dean, C.; Lizdas, D.J.

1977-08-01

284

Flash vacuum pyrolysis of lignin model compounds  

Energy Technology Data Exchange (ETDEWEB)

Despite the extensive research into the pyrolysis of lignin, the underlying chemical reactions that lead to product formation are poorly understood. Detailed mechanistic studies on the pyrolysis of biomass and lignin under conditions relevant to current process conditions could provide insight into utilizing this renewable resource for the production of chemicals and fuel. Currently, flash or fast pyrolysis is the most promising process to maximize the yields of liquid products (up to 80 wt %) from biomass by rapidly heating the substrate to moderate temperatures, typically 500{degrees}C, for short residence times, typically less than two seconds. To provide mechanistic insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds that contain a {beta}-ether. linkage and {alpha}- or {gamma}-alcohol, which are key structural elements in lignin. The dominant products from the FVP of PhCH{sub 2}CH{sub 2}OPh (PPE), PhC(OH)HCH{sub 2}OPh, and PhCH{sub 2}CH(CH{sub 2}OH)OPh at 500{degrees}C can be attributed to homolysis of the weakest bond in the molecule (C-O bond) or 1,2-elimination. Surprisingly, the hydroxy-substituent dramatically increases the decomposition of PPE. It is proposed that internal hydrogen bonding is accelerating the reaction.

Cooney, M.J.; Britt, P.F.; Buchanan, A.C. III

1997-03-01

285

Experimental investigation of pyrolysis process of woody biomass mixture  

Science.gov (United States)

This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment, the sample mass inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650C. Average sample heating rates in the reactor were 21, 30 and 54 C/min. The sample mass before, during and after pyrolysis was determined using a digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas was achieved at the temperature slightly above 650C and ranged from 77 to 85%, while char yield ranged from 15 to 23%. Heating rate has significant influence on the pyrolytic gas and char yields. It was determined that higher pyrolysis temperatures and heating rates induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650C produced 2.4-2.72 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as woody biomass pyrolysis equipment.

Kosani?, Tijana R.; ?erani?, Mirjana B.; ?uri?, Slavko N.; Grkovi?, Vojin R.; Miloti?, Milan M.; Brankov, Saa D.

2014-06-01

286

Pyrolysis of waste plastic crusts of televisions.  

Science.gov (United States)

The disposal of waste plastic crusts of televisions is an issue that is gaining increasing interest around the world. In this investigation, the pyrolysis and catalytic cracking of the waste television crusts mainly composed of acrylonitrile--butadiene-styrene copolymer was studied. Thermogravimetric analysis was used for initial characterization of the pyrolysis of the waste plastic, but most of the investigations were carried out using a 600 mL tubing reactor. Effects of temperature, reaction time and catalyst on the pyrolysis of the waste television crusts were investigated. The results showed that the oil yield increased with increasing temperature or with prolongation of reaction time. With increasing temperature, the generating percentage of gasoline and diesel oil increased, but the heavy oil yield decreased. Zinc oxide, iron oxide and fluid catalytic cracking catalyst (FCC catalyst) were employed to perform a series of experiments. It was demonstrated that the liquid product was markedly improved and the reaction temperature decreased 100 degrees C when FCC was used. The composition ofpyrolysis oils was analysed using gas chromatography-mass spectrometry, and they contained 36.49% styrene, 19.72% benzenebutanenitrile, 12.1% alpha-methylstyrene and 9.69% dimethylbenzene. PMID:23240191

Liu, Xinmin; Wang, Zhen; Xu, Dongyan; Guo, Qingjie

2012-09-01

287

Pyrolysis of Spent Ion Exchange Resins - 12210  

International Nuclear Information System (INIS)

Organic ion exchangers (IEX) play a major and increasing role in the reactor coolant and other water purification processes. During their operation time they receive significant amounts of radioactivity, making their disposal, together with their organic nature, as medium active waste challenging. Processes applied so far do not eliminate the organic matter, which is unwanted in disposal facilities, or, if high temperatures are applied, raise problems with volatile radionuclides. NUKEM Technologies offers their well introduces process for the destruction of spent solvent (TBP), the pebble bed pyrolysis, now for the treatment of spent IEX (and other problematic waste), with the following benefits: the pyrolysis product is free of organic matter, and the operation temperature with approx. 500 deg. C keeps Cs radionuclides completely in the solid residue. (authors)

288

The Cyclic Strain Rate Dependence on Environmentally Assisted Cracking Behaviors of SA508 Gr. 1a Low Alloy Steel in 310 .deg. C Deoxygenated Water  

International Nuclear Information System (INIS)

Environmental fatigue damage is well known as a significant degradation mechanism in nuclear power plant (NPP). So, the environmental fatigue behaviors should be cautiously considered for assessment of the integrity and the safety of NPP. In result of many researches, it is reported that the reduction in fatigue life of low alloy steels (LASs) is induced by the environmentally assisted cracking (EAC) mechanisms, such as the metal dissolution and the hydrogen-induced cracking (HIC). However, since these mechanisms are usually influenced by multiple factors, there are no clear explanations about fatigue cracking behaviors in high temperature water. In this study, low cycle fatigue (LCF) tests were conducted to investigate the fatigue life of SA508 Gr. 1a LAS in 310 .deg. C deoxygenated water. Also, the fatigue surface and sectioned area were observed for evaluation of cyclic strain rate dependent EAC mechanism in high temperature water

289

Volatile Analysis by Pyrolysis of Regolith for Planetary Resource Exploration  

Science.gov (United States)

The extraction and identification of volatile resources that could be utilized by humans including water, oxygen, noble gases, and hydrocarbons on the Moon, Mars, and small planetary bodies will be critical for future long-term human exploration of these objects. Vacuum pyrolysis at elevated temperatures has been shown to be an efficient way to release volatiles trapped inside solid samples. In order to maximize the extraction of volatiles, including oxygen and noble gases from the breakdown of minerals, a pyrolysis temperature of 1400 C or higher is required, which greatly exceeds the maximum temperatures of current state-of-the-art flight pyrolysis instruments. Here we report on the recent optimization and field testing results of a high temperature pyrolysis oven and sample manipulation system coupled to a mass spectrometer instrument called Volatile Analysis by Pyrolysis of Regolith (VAPoR). VAPoR is capable of heating solid samples under vacuum to temperatures above 1300 C and determining the composition of volatiles released as a function of temperature.

Glavin, Daniel P.; Malespin, Charles; ten Kate, Inge L.; Getty, Stephanie A.; Holmes, Vincent E.; Mumm, Erik; Franz, Heather B.; Noreiga, Marvin; Dobson, Nick; Southard, Adrian E.; Feng, Steven H.; Kotecki, Carl A.; Dworkin, Jason P.; Swindle, Timothy D.; Bleacher, Jacob E.; Rice, James W.; Mahaffy, Paul R.

2012-01-01

290

Fuel-N Evolution during the Pyrolysis of Industrial Biomass Wastes with High Nitrogen Content  

OpenAIRE

In this study, sewage sludge and mycelial waste from antibiotic production were pyrolyzed in a batch scale fixed-bed reactor as examples of two kinds of typical industrial biomass wastes with high nitrogen content. A series of experiments were conducted on the rapid pyrolysis and the slow pyrolysis of these wastes in the temperature range from 500800 C to investigate the Fuel-N transformation behavior among pyrolysis products. The results showed that Fuel-N conversion to ...

Kunio Yoshikawa; Guangwen Xu; Hongfang Chen; Yin Wang

2012-01-01

291

Biomass pyrolysis processes: performance parameters and their influence on biochar system benefits  

OpenAIRE

This study focuses on performance of biomass pyrolysis processes for use in biochar systems. Objectives are to understand the range of control of such processes and how this affects potential benefits of pyrolysis biochar systems, in particular for climate change mitigation. Slow, intermediate and fast pyrolysis processes are reviewed. Product yield distributions change depending on feedstock composition and preparation, control of temperature and material flows. These allow s...

Brownsort, Peter A.

2009-01-01

292

Copper-carbon nanocomposites prepared by solid-phase pyrolysis of copper phthalocyanine  

International Nuclear Information System (INIS)

By using solid-phase pyrolysis of copper phthalocyanine we have prepared copper nanoparticles in carbon matrices. The elemental composition, structure and morphology of nanocomposites were investigated by scanning electron microscopy, energy dispersive X-ray microanalysis and X ray diffraction. Depending on the temperature and time of pyrolysis the sizes of copper nanoparticles can be varied from 10 nm to 400 nm. The structure of carbon matrices also strongly depends on the pyrolysis conditions, which allows to synthesize nanocomposites with given properties

293

Catalytic Deoxygenation of Renewable Chemicals Structure?Performance Studies  

DEFF Research Database (Denmark)

Generation of chemicals from a viable feedstock is an increasingly interesting field. One of the major issues is the high oxygen ratios in biomass. There are a multitude of ways to remove oxygen from organic molecules. This thesis deals with two topics: The dehydration of glucose into HMF and the decarbonylation of aldehydes both heterogeneous and in ionic liquids. Chapter 1 provides a walkthrough of areas such as green chemistry, ionic liquids, biomass, dehydration of glucose in ionic liquids and decarbonylation. The topics are all taking into account the current research and is subjectively chosen to provide a broad platform for the following chapters. Furthermore, the objectives for the thesis are listed here. Chapter 2 deals with the synthetic preparation of the catalysts and the catalytic setups. Chapter 3 deals with the dehydration of glucose into HMF in ionic liquids. The system was investigated thouroughly via several spectroscopic techniques. This was done in order to obtain novel information in regard to the catalytically active sites. EXAFS results showed that during the catalytic reaction, a species of the form CrCl4O2 was formed from CrCl6 in the solution. These are the predominant chromium containing species in the solution. EPR results showed the presence of a S= 1/2 spin system, and the only possible choice is radical formation. Optical absorption spectroscopy showed a change in the ligand field around the chromium. Chapter 3 also deals with the homogeneous decarbonylation of aldehydes. The investigation of the effects of the ionic liquids in the catalytically active species is investigated in depth and the system [Rh(dppp)2]Cl in BMImCl was shown to be the most active combination. The reusability of the system showed great potential. The system showed a potential to decarbonylate both aliphatic and aromatic aldehydes. Finally Chapter 3 looks at the heterogeneous decarbonylation of aldehydes, focussing on a continuous flow setup. The catalytic effect of oxidation state and ligandsphere is investigated. And the effects of temperature, solvent and substrate were under scrutiny. The catalyst decomposition was pictured by the aid of TEM and the formation of nanoparticles explained. Chapter 4 concerns the summation of the results as well as the future perspectives for the respective applications and scientific developments.

Malcho, Phillip

2014-01-01

294

Organic emissions from coal pyrolysis: mutagenic effects.  

OpenAIRE

Four different types of coal have been pyrolyzed in a laminar flow, drop tube furnace in order to establish a relationship between polycyclic aromatic compound (PAC) evolution and mutagenicity. Temperatures of 900K to 1700K and particle residence times up to 0.3 sec were chosen to best simulate conditions of rapid rate pyrolysis in pulverized (44-53 microns) coal combustion. The specific mutagenic activity (i.e., the activity per unit sample weight) of extracts from particulates and volatiles...

Braun, A. G.; Wornat, M. J.; Mitra, A.; Sarofim, A. F.

1987-01-01

295

Pyrolysis and gasification behavior of black liquor under pressurized conditions  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study has been to enhance the understanding of the processes involved in pressurized black liquor gasification. Gasification is known to occur in three stages: drying, pyrolysis and char gasification. The work presented here focuses on the pyrolysis and gasification stages. Experiments were carried out primarily in two laboratory-scale reactors. A pressurized grid heater was used to study black liquor pyrolysis under pressurized conditions. Char yields and the fate of elements in the liquor, as well as the degree of liquor swelling, were measured in this device. A pressurized thermogravimetric reactor was used to measure the rate of the char gasification process under different temperatures and pressures and in various gas atmospheres. Pyrolysis experiments were also carried out in this device, and data on swelling behavior, char yields and component release were obtained 317 refs.

Whitty, K.

1997-11-01

296

Pyrolysis, combustion and gasification characteristics of Nannochloropsis gaditana microalgae.  

Science.gov (United States)

Pyrolysis, combustion and gasification characteristics of Nannochloropsis gaditana microalgae (NG microalgae) were investigated by thermogravimetric analysis (TGA). NG microalgae pyrolysis and combustion could be divided into three main stages: dehydration, proteins and polysaccharides degradation and char decomposition. The effects of the initial sample mass, particle size and gas flow on the pyrolysis and combustion processes were studied. In addition, gasification operation conditions such as temperature, initial sample mass, particle size, sweep gas flow and steam concentration, were experimentally evaluated. The evolved gases were analyzed online using mass spectroscopy (MS). In pyrolysis and combustion processes, most of the gas products were generated at the second degradation step. N-compounds evolution was associated with the degradation of proteins. Furthermore, SO(2) release from combustion could be related to sulphated polysaccharides decomposition. The main products detected during gasification were CO(2), CO, H(2), indicating that oxidation reactions, water gas and water gas shift reactions, were predominant. PMID:23313676

Sanchez-Silva, L; Lpez-Gonzlez, D; Garcia-Minguillan, A M; Valverde, J L

2013-02-01

297

Microwave pyrolysis of microalgae for high syngas production.  

Science.gov (United States)

The microwave induced pyrolysis of the microalgae Scenedesmus almeriensis and its extraction residue was carried out at 400 and 800C. The results show that it is possible to obtain a gas fraction with a high content (c.a. 50vol.%) in H2 from both materials, regardless of the pyrolysis temperature. Furthermore, an outstanding syngas production and high gas yields were achieved. The maximum syngas concentration obtained was c.a. 94 vol.%, in the case of the pyrolysis of the residue at 800C, indicating that the production of CO2 and light hydrocarbons was minimized. The same experiments were carried out in a conventional electric furnace in order to compare the products and yields obtained. It was found that microwave induced pyrolysis gives rise not only to higher gas yields but also to greater syngas and H2 production. PMID:23871926

Beneroso, D; Bermdez, J M; Arenillas, A; Menndez, J A

2013-09-01

298

Fuel Nitrogen Evolution during Coal Pyrolysis and Gasification  

Science.gov (United States)

The morphology of fuel nitrogen in coal and its fate during pyrolysis and the nitrogen species including N2, HCN and NH3 during coal pyrolysis and gasification have been investigated to clarify the evolution mechanism of fuel nitrogen in heat treatment process. Experimental results show that the morphology of coal nitrogen in the studied Chinese raw coals generally include pyrrolic nitrogen (N-5), pyridinic nitrogen (N-6), quaternary nitrogen (N-Q) and nitrogen-oxide (N-X). Generally, nitrogen in char is transformed to volatile and more stable components during pyrolysis. Char-N is the major source of NOx precursors during temperature programmed pyrolysis in 600-800 C. N-5 and N-X in char is converted to HCN first, and HCN is then hydrogenated to NH3. N-Q in char is the main source of nitrogen gas. The major nitrogenous gas products during rapid coal pyrolysis are N2, HCN and NH3, amongst which N2 is dominant. The yields of N2 and NOx precursors, such as HCN and NH3, increase with increased pyrolysis temperature. The major gaseous nitrogenous products during coal gasification in steam include HCN, NH3 and N2. H2O is the main source of the groups containing hydrogen, which not only participates in the reaction as a gasification agent, but also has catalysis on the reaction.

Che, Defu; Liu, Yinhe; Lin, Junguang

2010-03-01

299

Pyrolysis of polystyrene - polyphenylene oxide to recover styrene and useful products  

Science.gov (United States)

A process of using fast pyrolysis in a carrier gas to convert a polystyrene and polyphenylene oxide plastic waste to a given polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components therein comprising: selecting a first temperature range to cause pyrolysis of given polystyrene and polyphenylene oxide and its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and a support and treating the feed stream with the catalyst to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of high value monomeric constituent of styrene from polystyrene and polyphenylene oxide in the first temperature range; differentially heating the feed stream at a heat rate within the first temperature range to provide differential pyrolysis for selective recovery of the high value monomeric constituent of styrene from polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components; separating the high value monomer constituent of styrene; selecting a second higher temperature range to cause pyrolysis to a different derived high value product of polyphenylene oxide from the plastic waste and differentially heating the feed stream at the higher temperature range to cause pyrolysis of the plastic into a polyphenylene oxide derived product; and separating the different derived high value polyphenylene oxide product.

Evans, Robert J. (Lakewood, CO); Chum, Helena L. (Arvada, CO)

1995-01-01

300

Pyrolysis process and apparatus  

Science.gov (United States)

This invention discloses a process and apparatus for pyrolyzing particulate coal by heating with a particulate solid heating media in a transport reactor. The invention tends to dampen fluctuations in the flow of heating media upstream of the pyrolysis zone, and by so doing forms a substantially continuous and substantially uniform annular column of heating media flowing downwardly along the inside diameter of the reactor. The invention is particularly useful for bituminous or agglomerative type coals.

Lee, Chang-Kuei (Sewell, NJ)

1983-01-01

301

Quality improvement of pyrolysis oil from waste rubber by adding sawdust.  

Science.gov (United States)

This work was aimed at improving the pyrolysis oil quality of waste rubber by adding larch sawdust. Using a 1 kg/h stainless pyrolysis reactor, the contents of sawdust in rubber were gradually increased from 0%, 50%, 100% and 200% (wt%) during the pyrolysis process. Using a thermo-gravimetric (TG) analyzer coupled with Fourier transform infrared (FTIR) analysis of evolving products (TG-FTIR), the weight loss characteristics of the heat under different mixtures of sawdust/rubber were observed. Using the pyrolysis-gas chromatography (GC)-mass spectrometry (Py-GC/MS), the vapors from the pyrolysis processes were collected and the compositions of the vapors were examined. During the pyrolysis process, the recovery of the pyrolysis gas and its composition were measured in-situ at a reaction temperature of 450 C and a retaining time of 1.2s. The results indicated that the efficiency of pyrolysis was increased and the residual carbon was reduced as the percentage of sawdust increased. The adding of sawdust significantly improved the pyrolysis oil quality by reducing the polycyclic aromatic hydrocarbons (PAHs) and nitrogen and sulfur compounds contents, resulting in an improvement in the combustion efficiency of the pyrolysis oil. PMID:25223439

Wang, Wen-liang; Chang, Jian-min; Cai, Li-ping; Shi, Sheldon Q

2014-12-01

302

Thermodynamic analysis for syngas production from volatiles released in waste tire pyrolysis  

International Nuclear Information System (INIS)

Highlights: Pyrolysis experiments have been conducted in a continuous auger reactor. Pyrolysis temperature influence on composition of both volatiles and char was studied. A process for syngas production has been proposed from the volatiles. Equivalence ratio down to 0.4 is a practical limit for syngas production. The results provide essential data prior to perform any experimental campaign. - Abstract: This paper shows the maximum limit on syngas composition obtained from volatiles released in waste tire pyrolysis when they are submitted to an airsteam partial oxidation process. Thus, from mass and energy balances and a stoichiometric equilibrium model, syngas composition and reaction temperature as well as some process parameters were predicted by varying both the equivalence ratio (ER) and the steam to fuel ratio (SF). In addition, pyrolysis experiments were performed using a continuous auger reactor, and the influence of pyrolysis temperature on composition of both volatiles and char was studied. Consequently, the resulting syngas characteristics were correlated with the pyrolysis temperature. The stoichiometric equilibrium model showed that an ER down to 0.4 is a practical limit to perform the airsteam partial oxidation process. When the process is carried out only with air, volatiles obtained at high pyrolysis temperature lead to lower reaction temperature and higher LHV of syngas in comparison with those found at low pyrolysis temperature. The H2 production is favored between 0.20 and 0.40 of ER and seems to be more influenced by the H/C ratio than by the water gas-shift reaction. On the other hand, the steam addition shows a more notable effect on the H2 production for volatiles obtained at the highest pyrolysis temperature (600 C) in agreement with the lower reaction temperature under these experimental conditions. This thermodynamic analysis provides essential data on the optimization of syngas production from volatiles released in waste tire pyrolysis prior to run any test

303

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of polycarbonate and plastic waste to recover monomers  

Science.gov (United States)

A process is described using fast pyrolysis to convert a plastic waste feed stream containing polycarbonate and ABS to high value monomeric constituents prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of a given polymer to its high value monomeric constituents prior to a temperature range that causes pyrolysis of other plastic components; selecting an acid or base catalysts and an oxide or carbonate support for treating the feed stream to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of the high value monomeric constituents of polycarbonate and ABS in the first temperature program range; differentially heating the feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituents prior to pyrolysis or other plastic components; separating the high value monomeric constituents from the polycarbonate to cause pyrolysis to a different high value monomeric constituent of the plastic waste and differentially heating the feed stream at the second higher temperature program range to cause pyrolysis of different high value monomeric constituents; and separating the different high value monomeric constituents. 68 figs.

Evans, R.J.; Chum, H.L.

1994-06-14

304

Pyrolysis pretreatment of biomass for entrained-flow gasification  

International Nuclear Information System (INIS)

The biomass for entrained-flow gasification needs to be pretreated to significantly increase its heating value and to make it more readily transportable. The pyrolysis pretreatment was conducted in a lab scale fixed-bed reactor; the reactor was heated to elevate the temperature at 5 C/min before holding at the desired pyrolysis temperature for 1.5 h a fixed time. The effects of pyrolysis temperature on the yield, composition and heating value of the gaseous, liquid and solid products were determined. The pyrolysis removed most oxygenated constituents of rice straw while significantly increased its energy density. Meantime, it changes the physical properties of biomass powders. The results show that the angle of repose, the angle of internal friction of semi-char decrease obviously; the bulk density of semi-char is bigger than that of biomass. This could favor the feeding of biomass. Considering yield and heating value of the solid semi-char product and the feeding problem, the best pyrolysis temperature was 400 C. The results of this study have confirmed the feasibility of employing pyrolyzed biomass for entrained-flow gasification; they are useful for the additional studies that will be necessary for designing an efficient biomass entrained-flow gasification system.

305

Slow Pyrolysis as a Method for the Destruction of Japanese Wireweed, Sargassum muticum  

Directory of Open Access Journals (Sweden)

Full Text Available Japanese wireweed, Sargassum muticum is an invasive species to Great Britain, which might be controlled by harvesting it for energy and chemicals. Pyrolysis is the thermal decomposition of the organic components of dry biomass by heating in the absence of air. The distribution of matter between solid, liquid and syngas depends on the biomass and the pyrolysis temperature and time. Slow pyrolysis with lower temperatures (~ 400 oC tends to produce more solid char. Pyrolysis char can be an effective soil ameliorant, a sequestration agent due to its stability or burned as a fuel. The research attempts to answer the question: Could slow pyrolysis be an energy efficient means for the destruction of Japanese wireweed and produce a potential product, biochar? A simple test rig was developed to establish the yield of biochar, biocrude and syngas from the slow pyrolysis of Sargassum muticum. An energy balance was calculated using compositional data from the analysis of the seaweed feedstock, higher heating values (HHV from bomb-calorimetry and literature values. The energy required to heat 1 kg of dry seaweed by 400 oC for slow pyrolysis was estimated at 0.5 MJ. The HHV of syngas and biocrude produced from the pyrolysis totalled 2.9 MJ. There is, therefore, sufficient energy in the biocrude and syngas fractions produced by the pyrolysis of seaweed to power the process and produce useful biochar, but insufficient energy for drying.

John J Milledge

2014-12-01

306

UVC emitting phosphors obtained by spray pyrolysis  

International Nuclear Information System (INIS)

The broadband inter-configurational (4f15d1?4f2) emission of Pr3+ doped in lanthanum orthophosphate (LaPO4) and in calcium pyrophosphate (Ca2P2O7) has been investigated under plasma excitation. The synthesis by spray pyrolysis at moderate temperature followed by a controlled annealing proves to be a very efficient way to produce good quality UVC emitting phosphor Ca1.92Pr0.04Na0.04P2O7 (? phase). The emission of this phosphor in the wavelength range 200-350 nm has been measured with a prototype device, which can be employed for anti-microbial testing. - Research Highlights: ? The Pr3+ doped orthophosphate and pyrophosphate were synthesized by spray pyrolysis. ? The dense particles present good quality UVC emitting (200-350 nm). ? The prototype device can be employed for anti-microbial testing.

307

Validation Results for Core-Scale Oil Shale Pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes a study of oil shale pyrolysis at various scales and the subsequent development a model for in situ production of oil from oil shale. Oil shale from the Mahogany zone of the Green River formation was used in all experiments. Pyrolysis experiments were conducted at four scales, powdered samples (100 mesh) and core samples of 0.75, 1 and 2.5 diameters. The batch, semibatch and continuous flow pyrolysis experiments were designed to study the effect of temperature (300C to 500C), heating rate (1C/min to 10C/min), pressure (ambient and 500 psig) and size of the sample on product formation. Comprehensive analyses were performed on reactants and products - liquid, gas and spent shale. These experimental studies were designed to understand the relevant coupled phenomena (reaction kinetics, heat transfer, mass transfer, thermodynamics) at multiple scales. A model for oil shale pyrolysis was developed in the COMSOL multiphysics platform. A general kinetic model was integrated with important physical and chemical phenomena that occur during pyrolysis. The secondary reactions of coking and cracking in the product phase were addressed. The multiscale experimental data generated and the models developed provide an understanding of the simultaneous effects of chemical kinetics, and heat and mass transfer on oil quality and yield. The comprehensive data collected in this study will help advance the move to large-scale in situ oil production from the pyrolysis of oil shale.

Staten, Josh; Tiwari, Pankaj

2015-03-01

308

Dechlorination of fuels in pyrolysis of PVC containing plastic wastes  

Energy Technology Data Exchange (ETDEWEB)

The objective of this work is the study of several dechlorination methods devoted to reduce the chlorine content of the liquids obtained in pyrolysis of PVC containing plastic wastes. A mixture of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyvinyl chloride (PVC) has been pyrolysed in a 3.5 dm{sup 3} semi-batch reactor at 500 C for 30 min. Stepwise pyrolysis carried out at several temperature and time conditions, the addition of CaCO{sub 3} for chlorine capture and a combination of both methods have been studied. Additionally, some thermogravimetric analyses have been carried out in order to establish the best conditions for PVC dehydrochlorination in the presence of other plastics. It has been proved that the application of dehydrochlorination methods plays a significant role in the characteristics of pyrolysis liquids. Stepwise pyrolysis is an effective method for reduction of the chlorine content of pyrolysis liquids; additionally, heavier hydrocarbons and lower quantity of aromatics in the liquids than in conventional pyrolysis are obtained. The addition of CaCO{sub 3} leads to the retention of a significant amount of chlorine in the solid, but more chlorine than in a conventional run is found in the liquids, which contains a higher amount of aromatics. (author)

Lopez, A.; Marco, I. de; Caballero, B.M.; Laresgoiti, M.F.; Adrados, A. [School of Engineering of Bilbao (Spain). Chemical and Environmental Engineering Dept.

2011-02-15

309

Microwave Heating Applied to Pyrolysis  

OpenAIRE

the MW pyrolysis as an original thermochemical process of materials is presented. This chapter comprises a general overview of the thermochemical and quantifying aspects of the pyrolysis process, including current application togethe with a compilation of the most frequently used materials

Ferna?ndez, Yolanda; Arenillas, Ana; Mene?ndez, J. A?ngel

2011-01-01

310

Pyrolysis of Softwood Carbohydrates in a Fluidized Bed Reactor  

Directory of Open Access Journals (Sweden)

Full Text Available In the present work pyrolysis of pure pine wood and softwood carbohydrates, namely cellulose and galactoglucomannan (the major hemicellulose in coniferous wood, was conducted in a batch mode operated fluidized bed reactor. Temperature ramping (5°C/min was applied to the heating until a reactor temperature of 460 °C was reached. Thereafter the temperature was kept until the release of non-condensable gases stopped. The different raw materials gave significantly different bio-oils. Levoglucosan was the dominant product in the cellulose pyrolysis oil. Acetic acid was found in the highest concentrations in both the galactoglucomannan and in the pine wood pyrolysis oils. Acetic acid is most likely formed by removal of O-acetyl groups from mannose units present in GGM structure.

Dmitry Yu. Murzin

2008-09-01

311

Proportions of gas, liquid, and char from pyrolysis of biomass  

Energy Technology Data Exchange (ETDEWEB)

The proportions of gas, liquid, and char obtained from pyrolysis of four materials at each of eight temperatures are discussed. At the three lowest temperatures (675, 725, 775 K), a plot of proportion char versus proportion gas is approximately a single straight line for three of the materials (hazelnut shell, tobacco stalk, yellow pine wood). A statistical model for this is proposed. (Author)

Hutchinson, T. [Macquarie Univ., Sydney (Australia). Dept. of Psychology

2005-08-15

312

RATES AND EQUILIBRIA OF DEVOLATILIZATION AND TRACE ELEMENT EVOLUTION IN COAL PYROLYSIS  

Science.gov (United States)

The report gives results of using a laminar-flow furnace to study the kinetics of devolatilization and evolution of S, As, Pb, and Hg in the pyrolysis of pulverized coal in nitrogen. Variables included pyrolysis time, reactor temperature, and coal type. Devolatilization rates and...

313

Pyrolysis and hydrolysis of mixed polymer waste comprising polyethylene-terephthalate and polyethylene to sequentially recover [monomers  

Science.gov (United States)

A process is described for using fast pyrolysis in a carrier gas to convert a plastic waste feed stream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feed stream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Evans, R.J.; Chum, H.L.

1998-10-13

314

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of phenolic resin containing waste streams to sequentially recover monomers and chemicals  

Science.gov (United States)

A process of using fast pyrolysis in a carrier gas to convert a waste phenolic resin containing feedstreams in a manner such that pyrolysis of said resins and a given high value monomeric constituent occurs prior to pyrolyses of the resins in other monomeric components therein comprising: selecting a first temperature program range to cause pyrolysis of said resin and a given high value monomeric constituent prior to a temperature range that causes pyrolysis of other monomeric components; selecting, if desired, a catalyst and a support and treating said feedstreams with said catalyst to effect acid or basic catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said first temperature program range to utilize reactive gases such as oxygen and steam in the pyrolysis process to drive the production of specific products; differentially heating said feedstreams at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantity of said high value monomeric constituent prior to pyrolysis of other monomeric components therein; separating said high value monomeric constituent; selecting a second higher temperature program range to cause pyrolysis of a different high value monomeric constituent of said phenolic resins waste and differentially heating said feedstreams at said higher temperature program range to cause pyrolysis of said different high value monomeric constituent; and separating said different high value monomeric constituent.

Chum, Helena L. (Arvada, CO); Evans, Robert J. (Lakewood, CO)

1992-01-01

315

Slow Pyrolysis of Cassava Wastes for Biochar Production and Characterization  

Directory of Open Access Journals (Sweden)

Full Text Available Production of biochar from slow pyrolysis of biomass is a promising carbon negative procedure since it removes the net carbon dioxide in the atmosphere and produce recalcitrant carbon suitable for sequestration in soil. Biochar production can vary significantly with the pyrolysis parameter. This study investigated the impact of temperature and heating rate on the yield and properties of biochar derived from cassava plantations residues which are cassava stem (CS and cassava rhizome (CR. The pyrolysis temperatures ranged from 400C to 600C while the heating rate parameter was varied from 5C/min to 25C/min. The experiment was conducted using the lab scale slow pyrolysis system. The increment of temperature and heating rate of slow pyrolysis for both cassava wastes had raised the fixed carbon content of the biochar but decreased the biochar yield. More biochar was produced at lower temperature and lower heating rate. Temperature gave more influence on the biochar yield as compared to the heating rate parameter. The highest biochar yield of more than 35 mf wt. % can be obtained from both CS and CR at 400C and heating rate of 5C/min. From the proximate analysis, the results showed that cassava wastes contain high percentage of volatile matter which is more than 80 mf wt. %. Meanwhile, the biochar produced from cassava wastes contain high percentage of fixed carbon which is about 5?8 times higher than their raw samples. This suggested that, it is a good step to convert CS and CR into high carbon biochar via slow pyrolysis process that can substantially yield more biochar, up to 37 mf wt. % in this study. Since the fixed carbon content for both CS and CR biochar produced in any studied parameter were found to be more than 75 mf wt. %, it is suggested that biochar from cassava wastes is suitable for carbon sequestration.

Nurhidayah Mohamed Noor

2012-01-01

316

Fuel-N Evolution during the Pyrolysis of Industrial Biomass Wastes with High Nitrogen Content  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, sewage sludge and mycelial waste from antibiotic production were pyrolyzed in a batch scale fixed-bed reactor as examples of two kinds of typical industrial biomass wastes with high nitrogen content. A series of experiments were conducted on the rapid pyrolysis and the slow pyrolysis of these wastes in the temperature range from 500800 C to investigate the Fuel-N transformation behavior among pyrolysis products. The results showed that Fuel-N conversion to Char-N intimately depended on the pyrolysis temperature and the yield of Char-N reduced with the increase of the pyrolysis temperature. Under the same pyrolysis conditions, Tar-N production mainly depended on complex properties of the different biomasses, including volatile matter, nitrogen content and biomass functional groups. HCN was the predominant NOx precursor in the rapid pyrolysis of biomass, whereas in the slow pyrolysis of mycelial waste, more NH3 was produced than HCN due to the additional NH3 formation through the hydrogenation reaction of Char-N, HCN and H radicals. At the same time, some part of the char was analyzed by Fourier Transform infrared spectroscopy (FTIR to get more information on the nitrogen functionality changes and the tar was also characterized by Gas Chromatography and Mass Spectrometry (GCMS to identify typical nitrogenous tar compounds. Finally, the whole nitrogen distribution in products was discussed.

Kunio Yoshikawa

2012-12-01

317

Pyrolysis and dehalogenation of plastics from waste electrical and electronic equipment (WEEE): a review.  

Science.gov (United States)

Plastics from waste electrical and electronic equipment (WEEE) have been an important environmental problem because these plastics commonly contain toxic halogenated flame retardants which may cause serious environmental pollution, especially the formation of carcinogenic substances polybrominated dibenzo dioxins/furans (PBDD/Fs), during treat process of these plastics. Pyrolysis has been proposed as a viable processing route for recycling the organic compounds in WEEE plastics into fuels and chemical feedstock. However, dehalogenation procedures are also necessary during treat process, because the oils collected in single pyrolysis process may contain numerous halogenated organic compounds, which would detrimentally impact the reuse of these pyrolysis oils. Currently, dehalogenation has become a significant topic in recycling of WEEE plastics by pyrolysis. In order to fulfill the better resource utilization of the WEEE plastics, the compositions, characteristics and dehalogenation methods during the pyrolysis recycling process of WEEE plastics were reviewed in this paper. Dehalogenation and the decomposition or pyrolysis of WEEE plastics can be carried out simultaneously or successively. It could be 'dehalogenating prior to pyrolysing plastics', 'performing dehalogenation and pyrolysis at the same time' or 'pyrolysing plastics first then upgrading pyrolysis oils'. The first strategy essentially is the two-stage pyrolysis with the release of halogen hydrides at low pyrolysis temperature region which is separate from the decomposition of polymer matrixes, thus obtaining halogenated free oil products. The second strategy is the most common method. Zeolite or other type of catalyst can be used in the pyrolysis process for removing organohalogens. The third strategy separate pyrolysis and dehalogenation of WEEE plastics, which can, to some degree, avoid the problem of oil value decline due to the use of catalyst, but obviously, this strategy may increase the cost of whole recycling process. PMID:22951495

Yang, Xiaoning; Sun, Lushi; Xiang, Jun; Hu, Song; Su, Sheng

2013-02-01

318

Pyrolysis characteristics of the mixture of printed circuit board scraps and coal powder.  

Science.gov (United States)

Thermogravimetric (TG) analysis and infrared spectroscopy were used to analyze the pyrolysis characteristics of printed circuit board scraps (PCBs), coal powder and their mixtures under nitrogen atmosphere. The experimental results show that there is a large difference between waste PCBs and coal powder in pyrolysis processing. The pyrolysis properties of the mixing samples are the result of interaction of the PCBs and coal powder, which is influenced by the content of mixture. The degree of pyrolysis and pyrolysis properties of the mixture are much better than that of the single component. The TG and the differential thermogravimetric (DTG) curves of the PCBs mixed with coal powder move towards the high-temperature zone with increasing amount of coal powder and subsequently the DTG peak also becomes wider. The Coats-Redfern integral method was used to determine the kinetic parameters of pyrolysis reaction mechanism with the different proportion of mixture. The gas of pyrolysis mainly composes of CO2, CO, H2O and some hydrocarbon. The bromide characteristic absorption peak has been detected obviously in the pyrolysis gas of PCBs. On the contrary, the absorption peak of the bromide is not obvious in pyrolysis gas of the PCBs samples adding 40% coal powder. PMID:24269060

Hao, Juan; Wang, Haifeng; Chen, Shuhe; Cai, Bin; Ge, Linhan; Xia, Wencheng

2014-10-01

319

Removal of organobromine compounds from the pyrolysis oils of flame retarded plastics using zeolite catalysts  

Energy Technology Data Exchange (ETDEWEB)

Two flame retarded plastics have been pyrolysed in the presence of two zeolite catalysts to remove the organobromine compounds from the derived pyrolysis oil. The flame retarded plastics were, acrylonitrile-butadiene-styrene (ABS) that was flame retarded with tetrabromobisphenol A and high impact polystyrene (HIPS) that was flame retarded with decabromodiphenyl ether. The two catalysts investigated were zeolite ZSM-5 and zeolite Y-Zeolite. Pyrolysis was carried out in a fixed bed reactor at a final pyrolysis temperature of 440 C. The pyrolysis gases were passed immediately to a fixed bed of the catalyst. It was found that the presence of zeolite catalysts increased the amount of gaseous hydrocarbons produced during pyrolysis but decreased the amount of pyrolysis oil produced. In addition, significant quantities of coke were formed on the surface of the catalysts during pyrolysis. The zeolite catalysts were found to reduce the formation of some valuable pyrolysis products such as styrene and cumene, but other products such as naphthalene were formed instead. The zeolite catalysts, especially Y-Zeolite, were found to be very effective at removing volatile organobromine compounds. However, they were less effective at removing antimony bromide from the volatile pyrolysis products, although some antimony bromide was found on the surfaces of the spent catalysts. (author)

Hall, William J.; Williams, Paul T. [Energy and Resources Research Institute, University of Leeds, Leeds LS2 9JT (United Kingdom)

2008-03-15

320

Rapid pyrolysis of coals in a down-flow reactor. (1). ; Rapid pyrolysis of Taiheiyo coal. Down-flow hoshiki ni yoru sekitan no kyusoku netsubunaki. (1). ; Taiheiyotan no kyusoku netsubunkai  

Energy Technology Data Exchange (ETDEWEB)

Rapid pyrolysis of Taiheiyo coal is studied on relations between conditions, product distribution and properties using the manufactured down-flow reactor which is heated by high temperature sand as a heat carrier. Char yield decreases and gas yield increases with an increase of pyrolysis temperature and length of heating section. In case of a longer length of the heating section, the secondary pyrolysis of the produced tar occurs. Rapid pyrolysis of coal finishes in a second order and the maximum pyrolysis rate depends on pyrolysis temperature. Effect of the temperature of sand as a heat carrier is not large. The calorific value of the produced char is higher than that of raw coal and combustion property is as good as raw coal. The produced gas is composed of H {sub 2}, CH {sub 4}, CO {sub 2}, CO and C {sub 2}-C {sub 4} gases, and H {sub 2} and CH {sub 4} increase, together with the secondary pyrolysis of tar. The produced gas has high calorific value of 5000 - 8500 kcal/N {sub 3}. The produced tar is high in the pyrolysis temperature and changes to aromatic since carbon increases and hydrogen and oxygen decrease, together with the secondary pyrolysis to be conspicuous. The calorific value of the produced tar is 6000 - 75000 kcal/kg. 15 refs., 11 figs., 6 tabs.

Hirosawa, K.; Morita, M. (Government Industrial Development Laboratory of Hokkaido, Sapporo (Japan))

1991-04-20

321

Flash pyrolysis fuel oil: BIO-POK  

Energy Technology Data Exchange (ETDEWEB)

Flash pyrolysis oil from Ensyn Tech., Canada and Union Fenosa, Spain was combusted with simple pressure atomisation equipment commonly used with light fuel oils in intermediate size (0.1-1 MW) boilers. With a number of modifications to the combustion system, carbon monoxide (CO) and nitrous oxide (NO{sub x}) could be reduced to acceptable levels: CO < 30 ppm and NO{sub x} < 140 ppm. Particulate emissions which were initially very high (Bacharach 4-5) were reduced (Bach. 2-3) by system changes but are still higher than from light fuel oil (Bach. <1). The modifications to the combustion system were: acid resistant progressive cavity pump, higher oil preheat temperature and higher oil pressure than for light fuel oils, refractory section between burner and boiler warmed up to at least 800 deg C. In addition, it was necessary to store pyrolysis oil samples under inert conditions to prevent oxidation and to rinse nozzles with alcohol after shutdown to prevent coking. The complexity and cost of these system modifications are considered to be too great for current grades of flash pyrolysis oil to be sold as a light fuel oil replacement. Improvements to fuel quality will be necessary. The main improvements are lowering of viscosity and improving of stability

Gust, S. [Neste Oy, Porvoo (Finland)

1995-12-31

322

Thermal Pyrolysis of Polyethylene: Kinetic Study  

Directory of Open Access Journals (Sweden)

Full Text Available

Thermogravimetric analysis (TGA was used to measure the kinetic parameters of high density polyethylene in different operating conditions i.e. heating rate and nitrogen flow rate in a non isothermal condition. The Coats-Redfern method was used to calculate the kinetic parameters. An effort was made to investigate the effect of metal particles on plastic during pyrolysis. The results suggested that aluminum powder accelerates the pyrolysis reaction by enhancing the heat transfer. In addition, the kinetic reaction of pyrolysis was studied using a semi-batch reactor in a nitrogen atmosphere under isothermal and non-isothermal conditions. A first-order decomposition reaction was assumed and the rate constant was determined using an integral method. The rate constant was measured at different temperatures and was used to calculate the apparent activation energy and the pre-exponential factor of the reaction in an isothermal condition. Kinetic parameters were measured for individual compounds with carbon numbers ranging from C9 to C50 using the semi batch reactor under isothermal condition.

Key words: Kinetic; High density polyethylene; Isothermal; Non isothermal; TGA; Semi batch reactor

Elham Khaghanikavkani

2011-09-01

323

Pyrolysis of oil sludge in a fluidised bed reactor.  

Science.gov (United States)

The oil sludge of tanker cleaning was pyrolysed in fluidised bed reactors. Three experiments were conducted in a laboratory plant and two on a technical plant. Separation of oil from the solids and distribution of the oil products were investigated at temperatures from 460 degrees C to 650 degrees C. Between 70% and 84% of the oil could be separated from the solids. Distribution of the oil products depended on the feed material and the pyrolysis conditions. The higher the temperature the more the oil was cracked into low boiling compounds. Under the conditions of pyrolysis carbon reduced gridiron to iron. Thus some solid fractions were pyrophoric and oxidised with high heat generation. Therefore the solid products have to be turned into inert substances. The fluidised bed pyrolysis is an adequate process to recycle oil sludge with high yields. PMID:11592417

Schmidt, H; Kaminsky, W

2001-10-01

324

Oil production by entrained pyrolysis of biomass and processing of oil and char  

Science.gov (United States)

Entrained pyrolysis of lignocellulosic material proceeds from a controlled pyrolysis-initiating temperature to completion of an oxygen free environment at atmospheric pressure and controlled residence time to provide a high yield recovery of pyrolysis oil together with char and non-condensable, combustible gases. The residence time is a function of gas flow rate and the initiating temperature is likewise a function of the gas flow rate, varying therewith. A controlled initiating temperature range of about 400.degree. C. to 550.degree. C. with corresponding gas flow rates to maximize oil yield is disclosed.

Knight, James A. (Atlanta, GA); Gorton, Charles W. (Atlanta, GA)

1990-01-02

325

Effect of support-active phase interactions on the catalyst activity and selectivity in deoxygenation of triglycerides.  

Czech Academy of Sciences Publication Activity Database

Ro?. 145, FEB 2014 (2014), s. 101-107. ISSN 0926-3373 R&D Projects: GA ?R GBP106/12/G015 Institutional support: RVO:61388955 Keywords : Deoxygenation * Vegetable oils * Effect of support Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.007, year: 2013

Kubi?ka, D.; Hor?ek, J.; Setni?ka, M.; Bulnek, R.; Zukal, Arnot; Kubi?kov, I.

2014-01-01

326

The role of Ni species in the deoxygenation of rapeseed oil over NiMo-alumina catalysts.  

Czech Academy of Sciences Publication Activity Database

Ro?. 397, 1-2 (2011), s. 127-137. ISSN 0926-860X Institutional research plan: CEZ:AV0Z40400503 Keywords : deoxygenation * NiMo-alumina * UV-vis Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.903, year: 2011

Priecel, P.; Kubi?ka, D.; ?apek, L.; Bastl, Zden?k; Rynek, P.

2011-01-01

327

Environmental fatigue behaviors of wrought and cast stainless steels in 310degC deoxygenated water  

International Nuclear Information System (INIS)

Environmental fatigue behaviors of wrought type 316LN stainless steel and cast CF8M stainless steel were investigated. Low cycle fatigue tests were performed in a 310degC deoxygenated water environment at a strain rate of 0.04%/s with various strain amplitudes. It was shown that the low cycle fatigue life of CF8M was slightly longer than that of 316LN. To understand the causes of the difference, fracture surface was observed and material factors like microstructure, mechanical properties, and chemical compositions of both materials were analyzed. In a duplex microstructure of CF8M, the fatigue crack growth was affected by barrier role of ferrite phase and acceleration role of microvoids in ferrite phase. Test results indicate that the former is greater than the latter, resulting in slower fatigue crack growth rate, or longer LCF lives in CF8M than in 316LN. (author)

328

Oxidative pyrolysis of solid fuels  

Energy Technology Data Exchange (ETDEWEB)

This study addresses the dependence of the rate and pattern of pyrolysis of solid fuels from the oxidizing versus inert nature of the gaseous atmosphere. A selection of four solid fuels is considered in the study, namely two plastics (polyethylene and polyethylene terephthalate), one lignocellulosic material (Robinia Pseudoacacia) and a South African bituminous coal. Fuels are pyrolyzed in a thermogravimetric apparatus at different heating rates, under inert conditions or in the presence of oxygen at different concentration.Results indicate that the action exerted by oxygen during pyrolysis depends on the nature of the fuel and on the process conditions such as heating rate and oxygen concentration. Larger heating rates and larger oxygen concentration may indeed emphasize differences between inert and oxidative pyrolysis. Further analysis is directed to check the adequacy of a power low kinetic expression to describe the dependence of the rate of oxidative pyrolysis from the level of oxygen concentration.

Senneca, Osvalda; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, C.N.R., P.le Tecchio 80, 80125 Napoli (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le Tecchio 80, 80125 Napoli (Italy)

2004-06-01

329

Pyrolysis of furan in a microreactor  

Science.gov (United States)

A silicon carbide microtubular reactor has been used to measure branching ratios in the thermal decomposition of furan, C4H4O. The pyrolysis experiments are carried out by passing a dilute mixture of furan (approximately 0.01%) entrained in a stream of helium through the heated reactor. The SiC reactor (0.66 mm i.d., 2 mm o.d., 2.5 cm long) operates with continuous flow. Experiments were performed with a reactor inlet pressure of 100-300 Torr and a wall temperature between 1200 and 1600 K; characteristic residence times in the reactor are 60-150 ?s. The unimolecular decomposition pathway of furan is confirmed to be: furan (+ M) rightleftharpoons ?-carbene or ?-carbene. The ?-carbene fragments to CH2=C=O + HC?CH while the ?-carbene isomerizes to CH2=C=CHCHO. The formyl allene can isomerize to CO + CH3C?CH or it can fragment to H + CO + HCCCH2. Tunable synchrotron radiation photoionization mass spectrometry is used to monitor the products and to measure the branching ratio of the two carbenes as well as the ratio of [HCCCH2]/[CH3C?CH]. The results of these pyrolysis experiments demonstrate a preference for 80%-90% of furan decomposition to occur via the ?-carbene. For reactor temperatures of 1200-1400 K, no propargyl radicals are formed. As the temperature rises to 1500-1600 K, at most 10% of the decomposition of CH2=C=CHCHO produces H + CO + HCCCH2 radicals. Thermodynamic conditions in the reactor have been modeled by computational fluid dynamics and the experimental results are compared to the predictions of three furan pyrolysis mechanisms. Uncertainty in the pressure-dependency of the initiation reaction rates is a possible a source of discrepancy between experimental results and theoretical predictions.

Urness, Kimberly N.; Guan, Qi; Golan, Amir; Daily, John W.; Nimlos, Mark R.; Stanton, John F.; Ahmed, Musahid; Ellison, G. Barney

2013-09-01

330

Characterization of fiber/matrix bonding strenth during the pyrolysis of CFRP to C/C composites  

OpenAIRE

The fiber/matrix bonding strength during the pyrolysis of CFRP to C/C composite was measured by single fiber push-out test with a microindentation method. The composites in their polymeric state show a high fiber/matrix bonding strength. After pyrolysis at elevated temperatures the fiber/matrix bonding strength decreases. Such result would be beneficial to the understanding of microstructure evolution mechanism during the pyrolysis of CFRP to C/C composites.

Sha, J.; Wu, G.; Dai, J.; Zhang, Y.; Hausherr, J. -m; Konschak, A.; Krenkel, W.

2011-01-01

331

Pyrolysis and co-pyrolysis of Laminaria japonica and polypropylene over mesoporous Al-SBA-15 catalyst  

Science.gov (United States)

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N2 adsorption-desorption isotherms, and NH3 temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H2O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32 wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro- d-galactitol and 1,5-anhydro- d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H2O content in bio-oil was decreased dramatically (8.93 wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis.

Lee, Hyung Won; Choi, Suek Joo; Park, Sung Hoon; Jeon, Jong-Ki; Jung, Sang-Chul; Kim, Sang Chai; Park, Young-Kwon

2014-08-01

332

Pyrolysis Modelling in a Wood Stove  

Directory of Open Access Journals (Sweden)

Full Text Available A simple empirical model for predicting the pyrolysis rate of fuel packed bed of a woodstove has been presented. The thermolytic behavior of the fuel bed has been approximated by a pseudo-first order reaction. The reaction rate constant has been determined as function of temperature. The effect of orientation of twigs in the fuel bed arrangement and twig diameter on the reaction rate constant has been analyzed. It has been concluded that the effect of twig orientation is insignificant while the peak magnitude of reaction rate constant increased with increasing twig diameter.

RAJESH GUPTA

2010-10-01

333

Pyrolysis reactor and fluidized bed combustion chamber  

Science.gov (United States)

A solid carbonaceous material is pyrolyzed in a descending flow pyrolysis reactor in the presence of a particulate source of heat to yield a particulate carbon containing solid residue. The particulate source of heat is obtained by educting with a gaseous source of oxygen the particulate carbon containing solid residue from a fluidized bed into a first combustion zone coupled to a second combustion zone. A source of oxygen is introduced into the second combustion zone to oxidize carbon monoxide formed in the first combustion zone to heat the solid residue to the temperature of the particulate source of heat.

Green, Norman W. (Upland, CA)

1981-01-06

334

Growth of polycrystalline SnS films by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Thin films of tin monosulfide (SnS) have been prepared by spray pyrolysis on Corning 7059 glass substrates with the substrate temperatures in the range 300-350 C, keeping the other deposition parameters constant. The films were characterised to evaluate the composition, structure, electrical resistivity and optical energy gap. (orig.) 10 refs.

Koteswara Reddy, N.; Ramakrishna Reddy, K.T. [Sri Venkateswara Univ., Tirupati (India). Dept. of Physics

1998-07-18

335

ANALYSIS OF VOLATILE PRODUCTS FROM THE SLOW PYROLYSIS OF COAL  

Science.gov (United States)

The report gives results of a study of the evolution of volatile matter from coals of various rank during fixed-and fluid-bed pyrolysis. The pyrolyses were performed at temperatures ranging from 400 to 1000 C and with heating rates ranging from 1.5 to 6.0 C/s. Effects of equilibr...

336

[Pyrolysis characteristics of medical waste compositions containing PVC (polyvinyl chloride)].  

Science.gov (United States)

To obtain pyrolysis characteristics of medical waste compositions containing PVC (polyvinyl chloride), thermogravimetric study of tube for transfusion (TFT) and sample collector for urine (SCFU) was carried out using the thermogravimetric analyser (TGA) with N2. The heat change in pyrolysis process was analyzed and the properties of pyrolysis residues are reported. The mathematics model with two-step and four-reaction was established to simulate the pyrolysis process. The results show that: 1) The pyrolysis mechanism of the two samples is in agreement with that of PVC. The decomposition process appears two stages in 200 - 390 degrees C and 390 - 550 degrees C, which are clearly expressed with two prominent peaks with maximum rate of weight loss at about 315 degrees C and 470 degrees C. 2) Complex ingredients in samples result in irregular and uneven shape of DTG peaks, in which plasticizer lowers the antichloration temperature and enhances the weight loss rate. 3) The model could satisfactorily describe the weight loss and differential process of TFT and SCFU. PMID:18649554

Deng, Na; Zhang, Yu-Feng; Zhao, Wei; Ma, Hong-Ting; Wei, Li-Li

2008-03-01

337

Co-pyrolysis of lignite and sugar beet pulp  

International Nuclear Information System (INIS)

Today, worldwide studies have been undertaken on the biomass usage and co-conversion of biomass and coal to seek out alternative fuels for supplying energy in an environmental friendly way. The objective of this work is to study co-pyrolysis of lignite and sugar beet pulp in 50/50 (wt./wt.) ratio of blend pellets, to elucidate their thermal behaviour under pyrolysis conditions and to assess major decomposition products in terms of their yields. A special chamber, which has enabled very fast heating rates, was used in the pyrolysis experiments carried at 600 deg. C. The results were interpreted in the light of liquid, solid and gaseous yields, resulting from thermal decomposition, and kinetics of thermogravimetric analysis. Proximate volatile matter and ash contents of the blends were different compared to those found by using individual values. Sugar beet pulp decomposed faster within a relatively narrow temperature range than lignite and underwent a significant shrinkage during pyrolysis. It was found that the chars left behind after the flash pyrolysis of these pellets at 600 deg. C have substantial amounts of volatile matter that would evolve upon further heating.

338

Pyrolysis of Softwood Carbohydrates in a Fluidized Bed Reactor  

OpenAIRE

In the present work pyrolysis of pure pine wood and softwood carbohydrates, namely cellulose and galactoglucomannan (the major hemicellulose in coniferous wood), was conducted in a batch mode operated fluidized bed reactor. Temperature ramping (5°C/min) was applied to the heating until a reactor temperature of 460 °C was reached. Thereafter the temperature was kept until the release of non-condensable gases stopped. The different raw materials gave significantly different bio-...

Dmitry Yu. Murzin; Tapio Salmi; Mikko Hupa; Bjarne Holmbom; Kari Eränen; Narendra Kumar,; Atte Aho

2008-01-01

339

Chemistry of hydrogen gas preparation by pyrolysis for the measurement of isotope ratios in hydrocarbons  

International Nuclear Information System (INIS)

The conventional oxidation/reduction preparation method for the determination of hydrogen isotope ratios in hydrocarbons suffers from being very time-consuming. A fast method in which the organic hydrogen is directly converted to hydrogen gas is highly desirable. This report discusses the chemistry involved in adapting high-temperature pyrolysis reactions for the direct conversion of organic hydrogen to hydrogen gas for isotope analysis. The report shows that high-temperature pyrolysis can be adapted to hydrogen isotope determinations provided that the organic matter contains only carbon and hydrogen atoms and that the pyrolysis technique is highly standardized

340

Pyrolysis of forestry biomass by-products in Greece  

Energy Technology Data Exchange (ETDEWEB)

This article summarizes the technical characteristics of a biomass pyrolysis pilot plant recently constructed in central Greece. It highlights the considerations involved in achieving successful pyrolysis technology and environmental and developmental goals, by reviewing technical and nontechnical barriers associated with biomass treatment technology in Greece. Data from the start-up phase of the plant operation are presented and some aspects of the process are outlined. The capacity of the plant is 1200 1450 kg hr, based on wet biomass (Arbutus Unedo) and the pyrolysis temperature is approximately 400{sup o}C. Char yield is 1418 % weight on dry basis and is of good quality consisting of 76{sup o}C with heat content 6760 kcal kg. Bio-oil includes 63% C and its heat content is 6250 kcal kg. (author)

Zabaniotou, A.A.

1999-06-01

341

Pyrolysis of forestry biomass by-products in Greece  

Energy Technology Data Exchange (ETDEWEB)

This article summarizes the technical characteristics of a biomass pyrolysis pilot plant recently constructed in central Greece. It highlights the considerations involved in achieving successful pyrolysis technology and environmental and developmental goals, by reviewing technical and nontechnical barriers associated with biomass treatment technology in Greece. Data from the start-up phase of the plant operation are presented and some aspects of the process are outlined. The capacity of the plant is 1200--1450 kg/hr, based on wet biomass (Arbutus Unedo) and the pyrolysis temperature is approximately 400 C. Char yield is 14--18% weight on dry basis and is of good quality consisting of 76% C with heat content 6760 kcal/kg. Bio-oil includes 64% C and its heat content is 6250 kcal/kg.

Zabaniotou, A.A. [Aristotle Univ. of Thessaloniki (Greece). Dept. of Chemical Engineering

1999-06-01

342

Experimental investigation of flash pyrolysis oil droplet combustion  

DEFF Research Database (Denmark)

The aim of this work is to investigate and compare the combustion behaviour of a single droplet of pyrolysis oil derived from wheat straw and heavy fossil oil in a single droplet combustion chamber. The initial oil droplet diameters were in between 500 ?m to 2500 ?m. The experiments were performed at a temperature ranging between 1000 and 1400C with an initial gas velocity of 1.6 m/s and oxygen concentration of 3%. The evolution of combustion of bio-oil droplets was recorded by a digital video camera. It was observed that the combustion behaviour of pyrolysis oil droplet differ from the heavy oil in terms both of ignition, devolatilisation and char oxidation. The pyrolysis oil is more difficult to ignite and has a shorter devolatilisation time and a longer char oxidation time. Copyright 2013, AIDIC Servizi S.r.l.

Ibrahim, Norazana; Jensen, Peter A.

2013-01-01

343

STEPWISE ISOTHERMAL FAST PYROLYSIS (SIFP. PART II. SIFP OF PEANUT SHELLS - ANTIFUNGAL PROPERTIES OF PHENOLIC FRACTIONS  

Directory of Open Access Journals (Sweden)

Full Text Available Pyrolysis of peanut shells was carried out using stepwise isothermal fast pyrolysis (SIFP. SIFP consists of successive isothermal fast pyrolysis reactions, where solid products obtained in the previous isothermal fast pyrolysis become the substrate of the subsequent reaction at a higher temperature. This article reports results obtained from SIFP of peanut shells between 200 and 300C using 100C intervals under vacuum (0.2 mm. The maximum yield of liquid products was obtained at 300C, giving around 30% of bio-oil, which contained mainly phenols and furan derivatives. On the other hand, since previous papers have reported fungicidal activity of phenols derivatives from lingo-cellulosic biomass pyrolysis, we carried out antifungal activity tests of bio oil obtained from peanut shells SIFT at 300 C. Results seem promising, at least on Sclerotium rolfsii.

Jorge Daniel Prez

2011-11-01

344

Kinetics of coal pyrolysis and devolatilization  

Energy Technology Data Exchange (ETDEWEB)

Research continued on coal pyrolysis and devolatilization. The effects of reaction process on the transient temperature history of a particle have been examined. The reaction process is found to significantly reduce the temperature gradient across a burning particle relative to a nonreactive particle. The pyrolysis process, on the other hand, does not severely affect the temperature history of a heating particle for the kinetic parameters employed. Devolatilization experiments have been performed on various size cuts on an HVA Bituminous coal in entrained flow and heated grid reactors. Weight loss measurements were made in the entrained flow reactor (EFR) and tar yields and molecular weight distributions were measured for the heated grid reactor (HGR) experiments. The results imply the initial phase of the devolatilization of the HVA Bituminous coal is heat transfer controlled because the rate of tar information and evolution is heat transfer controlled. The invariance in EFR ultimate weight loss and low pressure tar yields and characteristics with change in particle size can be explained by morphological considerations of the parent coal particles. The non-symmetric, irregular shapes of the coal particles result in an intraparticle mass distribution much nearer an interphase surface area than that of an equivalent sphere or cube. 5 refs., 37 figs., 9 tabs.

Seery, D.J.; Freihaut, J.D.; Proscia, W.M.

1991-01-01

345

Vacuum Pyrolysis and Related ISRU Techniques  

Science.gov (United States)

A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, process modeling, parts manufacturing, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a approx. l square meter Fresnel lens. This system was successfully used to vaporize quantities of approx. lg, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system With a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of approx. 10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

Cardiff, Eric H.; Pomeroy, Brian R.; Banks, Ian S.; Benz, Alexis

2007-01-01

346

Extreme warming, photic zone euxinia and sea level rise during the Paleocene/Eocene Thermal Maximum on the Gulf of Mexico Coastal Plain; connecting marginal marine biotic signals, nutrient cycling and ocean deoxygenation  

Science.gov (United States)

The Paleocene/Eocene Thermal Maximum (PETM, ~56 Ma) was a ~200 kyr episode of global warming, associated with massive injections of 13C-depleted carbon into the ocean-atmosphere system. Although climate change during the PETM is relatively well constrained, effects on marine oxygen and nutrient cycling remain largely unclear. We identify the PETM in a sediment core from the US margin of the Gulf of Mexico. Biomarker-based paleotemperature proxies (MBT/CBT and TEX86) indicate that continental air and sea surface temperatures warmed from 27-29 C to ~35 C, although variations in the relative abundances of terrestrial and marine biomarkers may have influenced the record. Vegetation changes as recorded from pollen assemblages supports profound warming. Lithology, relative abundances of terrestrial vs. marine palynomorphs as well as dinoflagellate cyst and biomarker assemblages indicate sea level rise during the PETM, consistent with previously recognized eustatic rise. The recognition of a maximum flooding surface during the PETM changes regional sequence stratigraphic interpretations, which allows us to exclude the previously posed hypothesis that a nearby fossil found in PETM-deposits represents the first North American primate. Within the PETM we record the biomarker isorenieratane, diagnostic of euxinic photic zone conditions. A global data compilation indicates that deoxygenation occurred in large regions of the global ocean in response to warming, hydrological change, and carbon cycle feedbacks, particularly along continental margins, analogous to modern trends. Seafloor deoxygenation and widespread anoxia likely caused phosphorus regeneration from suboxic and anoxic sediments. We argue that this fuelled shelf eutrophication, as widely recorded from microfossil studies, increasing organic carbon burial along continental margins as a negative feedback to carbon input and global warming. If properly quantified with future work, the PETM offers the opportunity to assess the biogeochemical effects of enhanced phosphorus regeneration, as well as the time-scales on which this feedback operates in view of modern and future ocean deoxygenation.

Sluijs, A.; van Roij, L.; Harrington, G. J.; Schouten, S.; Sessa, J. A.; LeVay, L. J.; Reichart, G.-J.; Slomp, C. P.

2013-12-01

347

Fast pyrolysis of sugarcane and cassava residues in a free-fall reactor  

International Nuclear Information System (INIS)

Fast pyrolysis of agricultural residues from sugarcane and cassava plantations was carried out in a laboratory-scale free-fall reactor unit. The objectives of this work were to investigate the effects of biomass types and pyroysis conditions, such as reactor temperature, condensation temperature, nitrogen flow rate and run duration, on pyrolysis product distribution, as well as to study the basic properties of the products. The results showed that all of the parameters affected the product distribution. The optimum reactor temperatures for maximising bio-oil yield were in the range of 350450 C. About 70 wt% of bio-oil yield could be obtained by pyrolysis of cassava stalk at a reactor temperature of 450 C and a primary condensation temperature of 10 C. It was also found that the minimum flow rate of nitrogen for obtaining high bio-oil yield was 1.5 l/min. The product characterisation showed that the bio-oil and char produced from the agricultural residues with the free-fall reactor unit were to a certain extent similar to those produced from different types of biomass with different types of pyrolysis reactor configurations. -- Highlights: ? Fast pyrolysis of sugarcane and cassava agricultural residues was carried out in a laboratory-scale free-fall reactor unit. ? The effects of process parameters on product yields were investigated. ? The process parameters included reactor temperature, condensation temperature, nitrogen flow rate and run duration. Basic properties of pyrolysis products were examined.

348

Rapid and slow pyrolysis of pistachio shell: effect of pyrolysis conditions on the product yields and characterization of the liquid product  

Energy Technology Data Exchange (ETDEWEB)

This study reports the experimental results for the pyrolysis of pistachio shell under different conditions in a tubular reactor under a nitrogen flow. For the different conditions of pyrolysis temperature, nitrogen flow rate and heating rate, pyrolysis temperature of 773 K gave the highest bio-oil yield with a value of 27.7% when the heating rate and carrier gas flow rate were chosen as 300 K min{sup -1} and 100 cm{sup 3} min{sup -1}, respectively. Column chromatography was applied to this bio-oil and its subfractions were characterized by elemental analysis, FT-IR and 1H-NMR. Aliphatic subfraction was conducted to gas chromatography-mass spectroscopy for further characterization. The results for the characterization show that using pistachio shell as a renewable source to produce valuable liquid products is applicable via pyrolysis. (Author)

Putun, Ayse E. [Department of Chemical Engineering, Anadolu University, Eskisehir 26470, (Turkey); Ozbay, Nurgul [Bozuyuk Vocational School, Anadolu University, Bozuyuk/Bilecik, (Turkey); Varol, Esin Apaydin; Uzun, Basak B.; Ates, Fuda [Department of Chemical Engineering, Anadolu University, Eskisehir 26470, (Turkey)

2006-10-30

349

Molecular characterization of vitrinite maturation as revealed by flash pyrolysis methods  

OpenAIRE

Curie-point pyrolysis - gas chromatography analyses were performed on four vitrinite concentrates of maturity levels from 0.96 %Rmax to 1.93 %Rmax. Analyses were carried out on "thermal extracts" obtained at a Curie-temperature of 358 C and on pyrolysates obtained at a Curie-temperature of 770 C. The relative concentrations of alkylphenols and alkylnaphthalenes decrease with increasing maturity. Alkylbenzenes are prominent pyrolysis products throughout the maturity interval investigated. ...

Sinninghe Damste?, J. S.; Veld, H.; Leeuw, J. W.; Fermont, W. J. J.

1994-01-01

350

Microwave pyrolysis for conversion of materials to energy : A review  

International Nuclear Information System (INIS)

Full text: The disposal of wastes in Malaysia is becoming a serious problem in many industrialized and public sectors. This is due to the high production of waste such as municipal solid waste, sludge from waste water treatment plants, agricultural waste and other used non-biodegradable products such as plastics and tyres. These wastes although are reused as compost, fuel, recycled and so on, there are still abundant left. These leftovers pose problems such as heavy metal leaching, leachates, green house gas emissions and mosquito breeding grounds. The disposal cost of these wastes sometimes can be costly at up to RM 2,200/ ton such as petroleum sludge by Kualiti Alam. Several methods have been used to convert these residues to energy via thermal treatment such as combustion, incineration and gasification. However, pyrolysis becomes one of the popular methods as the alternative to the wastes disposal recently. Not only energy (as gas) is produced, by-products such as chemical feedstock and solid absorbent can be produced. The use of microwave for pyrolysis, although relatively new for waste treatment, has several advantages compared to conventional heating. This includes easy control of the heating process, time saving, higher heating efficiency, etc. Tyre microwave pyrolysis plant in UK is known as the earliest plant using microwave technology to breakdown polymer in used tyres. Since 1990s, there are many patents for microwave pyrolysis. The processes are based on mve pyrolysis. The processes are based on microwave pyrolysis of waste include coffee hulls, wood, coal, sewage sludge, hospital waste, plastic wastes, corn cobs and rice straw. The most important factors influencing the yield of product during the pyrolysis is temperature in range from 500 to 1000 degree Celsius according to product preference. High temperature favors gas products; whereas lower temperature favors liquid products. Comparatively, microwave pyrolysis produced gas with higher hydrogen and carbon monoxide (syngas) content compared to conventional heating. Liquid product also showed considerable decrease in polycyclic aromatic hydrocarbons (PAH) production which is of known carcinogenic. Vitrification of heavy metals in solid product has also been proven. (author)

351

Low cycle fatigue behaviors of low alloy steels in 310 .deg. C deoxygenated water  

Energy Technology Data Exchange (ETDEWEB)

After low cycle fatigue tests of SA508 Gr.1a low alloy steel in 310 .deg. C deoxygenated water, the fatigue surface and the sectioned area of specimens were observed to understand the effect of the cyclic strain rate on the environmentally assisted cracking behaviors. From the fatigue crack morphologies of the specimen tested at a strain rate of 0.008 %/s, unclear ductile striations and blunt crack tip were observed. So, metal dissolution could be the main cracking mechanism of the material at the strain rate. On the other hand, on the fatigue surface of the specimen tested at strain rates of 0.04 and 0.4 %/s, the brittle cracks and the flat facets, which are the evidence of the hydrogen induced cracking, were observed. Also, the tendency of linkage between the main crack and micro-cracks was observed on the sectioned area. Therefore, the main cracking mechanism at the strain rates of 0.04 and 0.4 %/s could be the hydrogen induced cracking. Additionally, the evidence of the dissolved MnS inclusions was observed on the fatigue surface from energy dispersive x-ray spectrometer analyses. So, despite of the low sulfur content of the test material, the sulfides seem to contribute to environmentally assisted cracking of SA508 Gr.1a low alloy steel in 310 .deg. C deoxygenated water. Additionally, our experimental fatigue life data of SA508 Gr.1a low alloy steel (heat A) showed a consistent difference with statistical model produced in argon national laboratory. So, additional low cycle fatigue tests of other heat SA508 Gr.1a (heat B) and SA508 Gr.3 low alloy steels were performed to investigate the effect of material variability on fatigue behaviors of low alloy steels in 310 .deg. C deoxygenated water. In results, the fatigue lives of three low alloy steels were increased following order: SA508 Gr.1a low alloy steel - heat A, SA508 Gr.3 low alloy steel, and SA508 Gr.1a low alloy steel - heat B. From microstructure observation, the fatigue surface of SA508 Gr.1a low alloy steel - heat A showed ductile striations in ferrite phase. Also, secondary and surface crack of SA508 Gr.1a low alloy steel - heat A grew into ferrite phase and ferrite - pearlite phase boundaries. The increase in stress intensity at the pearlite crack tip by restricted strain may contribute to fatigue crack propagation along ferrite - pearlite phase boundaries. On the other hand, the fatigue surfaces of SA508 Gr.1a - heat B and SA508 Gr.3 low alloy steels showed relatively less striations due to their homogeneous carbides. And the secondary and surface cracks of SA508 Gr.1a low alloy steel - heat B and SA508 Gr.3 low alloy steel grew into ferrite phase between carbides. The homogeneous carbides could more effectively decrease the crack growth rate. Therefore, the fatigue crack growth rate in SA508 Gr.1a low alloy steel - heat A could be higher than those in SA508 Gr.1a low alloy steel - heat B and SA508 Gr.3 low alloy steel. Also, the fatigue crack growth rate of SA508 Gr.3 low alloy steel may be shorter than that SA508 Gr.1a low alloy steel - heat B due to its low ductility and high yield strength.

Jang, Hun

2008-02-15

352

Co-pyrolysis of coal with organic solids  

Energy Technology Data Exchange (ETDEWEB)

The co-pyrolysis of high volatile A bituminous coal with solid organic materials (proteins, cellulose, polyisoprene, polystyrene, polyethylene-glycolterephtalate-PEGT) at a high temperature conditions was investigated. Aim of the work was to evaluate, firstly, the changes of the texture and of the porous system of solid phase after high temperature treatment in presence of different types of macromolecular solids, secondly, properties and composition of the tar and gas. Considered organic solids are important waste components. During their co-pyrolysis the high volatile bituminous coal acts as a hydrogen donor in the temperature rank 220-480{degrees}C. In the rank 500- 1000{degrees}C the solid phase is formed. The co-pyrolysis was carried out at heating rate 3 K/min. It was found that an amount of organic solid (5-10%) affects important changes in the optical texture forms of solid phase, in the pore distribution and in the internal surface area. Transport large pores volume decreases in presence of PEGT, polystyrene and cellulose and increases in presence of proteins and polyisoprene. (image analysis measurements show that the tendency of coal to create coarse pores during co-pyrolysis is very strong and increases with increasing amount of organic solid in blend). An addition of considered materials changes the sorption ability (methylene blue test, iodine adsorption test), moreover, the reactivity of the solid phase.

Straka, P.; Buchtele, J. [Inst. of Rock Structure and Mechanics, Prague (Czechoslovakia)

1995-12-01

353

Development of advanced technologies for biomass pyrolysis  

Science.gov (United States)

The utilization of biomass resources as a renewable energy resource is of great importance in responding to concerns over the protection of the environment and the security of energy supply. This PhD research focuses on the investigation of the conversion of negative value biomass residues into value-added fuels through flash pyrolysis. Pyrolysis Process Study. A pilot plant bubbling fluidized bed pyrolyzer has been set up and extensively used to thermally crack various low or negative value agricultural, food and biofuel processing residues to investigate the yields and quality of the liquid [bio-oil] and solid (bio-char] products. Another novel aspect of this study is the establishment of an energy balance from which the thermal self-sustainability of the pyrolysis process can be assessed. Residues such as grape skins and mixture of grape skins and seeds, dried distiller's grains from bio-ethanol plants, sugarcane field residues (internal bagasse, external and whole plant) have been tested. The pyrolysis of each residue has been carried out at temperatures ranging from 300 to 600C and at different vapor residence times, to determine its pyrolysis behavior including yields and the overall energy balance. The thermal sustainability of the pyrolysis process has been estimated by considering the energy contribution of the product gases and liquid bio-oll in relation to the pyrolysis heat requirements. The optimum pyrolysis conditions have been identified in terms of maximizing the liquid blo-oil yield, energy density and content of the product blo-oil, after ensuring a self-sustainable process by utilizing the product gases and part of char or bio-oil as heat sources. Adownflow pyrolyzer has also been set up. Preliminary tests have been conducted using much shorter residence times. Bio-oil Recovery. Bio-oil recovery from the pyrolysis unit includes condensation followed by demisting. A blo-oil cyclonic condensing system is designed A nearly tangential entry forces the entering vapors and gases to spin, providing good heat transfer and driving the condensed droplets to the wall through cyclonic action. This condenser design has been successfully demonstrated for the application on the pilot fluidized bed pyrolysis unit. After condensation, a stable aerosol is also typically formed which is difficult to be efficiently captured with conventional technologies. A pilot scale helicoidal rotary demister, a novel technology for removing persistent fine bio-oil droplets from gases using dynamic centrifugal forces, has been developed. The demister uses a helicoidal element, which consists of a metal sheet wound as a spiral, designed to rotate at high speeds within a cyclone body. Larger droplets are separated as they enter the cyclone housing, while the smaller droplets are carried by the gas into the helicoidal path of the rotating element, where they are centrifuged towards the outer collecting walls and, as a result of a specially designed baffle, may flow counter-currently to the gas and are drained out from the bottom of the rotating element. The mist-free gas leaves through a channel located at the center of the spiral. This unique demister design has demonstrated a high separation efficiency when tested offline with artificial submicron mist and tested online for demisting bio-oil aerosol on the pyrolysis unit. Bio-oil Upgrading: Very often, phase separation of bio-oil occurs naturally upon condensation of the bio-oil vapors, typically through the use of cyclonic condensers. The bio-oil is separated into an organic phase and an aqueous phase. Research has been conducted on the possibility to enhance the fuel properties and energy performance of the organic phase by reducing its water content, enhancing its heating value and improving its stability. Through the use of drying agents, a remarkable reduction of water content and an increase of heating value can be achieved. Moreover, the volumetric energy density can be greatly enhanced. Besides, the energy yield of the process has also been investigated. (Abstract shortened by

Xu, Ran

354

Energy recovery from pyrolysis and gasification of mangrove  

International Nuclear Information System (INIS)

Highlights: ? The increase in reactor temperature increased the hydrogen yield and energy yield. ? The increase in reactor temperature increased the peak value of syngas flow rate. ? Cumulative yield of energy was calculated based on the time dependent results. ? Higher reactor temperatures shortened the time duration for 99% release of syngas. ? Gasification yielded more hydrogen and energy than that obtained from pyrolysis. -- Abstract: Mangrove is a biomass material that grows in wetland sea waters and is often used to produce charcoal due to its unique characteristics of long and sustained burning and negligible residue. High temperature pyrolysis has been conducted for mangrove biomass in a laboratory scale semi-batch reactor. The effect of reactor temperature on syngas yield and syngas characteristics has been investigated. Reactor temperature was varied from 600 to 900 C in 100 C intervals. The increase in reactor temperature resulted in increased syngas yield, hydrogen yield and energy yield. Evolutionary behavior of the syngas characteristics has also been investigated. The increase in reactor temperature increased the peak value of syngas flow rate, hydrogen flow rate and output power. The increase in reactor temperature decreased the time duration of pyrolysis. Cumulative yield of syngas, hydrogen and energy was calculated based on the time dependent relationship. Higher reactor temperatures shortened the time duration required for 99% release of syngas, hydrogen and energy. For example, time duration required for 99% yield of hydrogen was approximately 73 min at 600 C and only about 26 min at 900 C. Required time duration for 99% yield of energy was ?62 min at 600 C and ?15 min at 900 C. The gasification of the same material at 900 C has been carried out to determine the role of gasifying agent on the fate of material and resulting syngas properties. The results showed gasification yielded more syngas, hydrogen and energy than that obtained from pyrolysis.

355

Fast pyrolysis of lignin, macroalgae and sewage sludge  

Energy Technology Data Exchange (ETDEWEB)

Non-conventional biomass feedstock may also be applicable for fast pyrolysis processes. Among the forms of non-conventional biomasses, macroalgae, lignin (industrial residue) and sewage sludge may be attractive materials due to their low price, non-competitiveness with food crops and the possible utilization of solid wastes. Besides, a fast pyrolysis process can be used as a process to densify the biomass and produce bioslurry, a mixture of bio-oil and pyrolytic char. The bioslurry is found to be a possible feedstock for pressurized gasification plants. Thus, the aims of this project are to investigate fast pyrolysis properties of lignin, sewage sludge and macroalgae on a lab scale PCR and characterize their bio-oil properties. Bioslurry properties with respect to use as a feedstock for pressurized gasification is also investigated. Lignin and sewage sludge PCR pyrolysis provided bio-oil yields of 47 and 54 wt% daf, and oil energy recovery of 45 and 50 %, respectively. While the macroalgae PCR pyrolysis showed promising results with an organic oil yield of 65 wt% daf and an oil energy recovery of 76 %. The HHV of the lignin, sewage sludge and macroalgae oils were 29.7, 25.7 and 25.5 MJ/kg db respectively, and that are higher than that of typical bioiv oil from conventional biomasses (23-24 MJ/kg db). Almost all metals feedstock contents were contained in the chars at temperatures of 550 - 575 deg. C for lignin, sewage sludge and macroalgae PCR pyrolysis. Due to high feedstock nitrogen and sulfur contents, also a high level of nitrogen and sulfur of macroalgae and sewage sludge oils were observed compared to conventional bio-oil and this may limit their further industrial applications. The lignin char had a high proportion of small size particles, a HHV of 21 MJ/kg db and were almost free of chloride and sulfur, thus it is considered as a promising fuel for gasification or combustion; whereas macroalgae and sewage sludge chars containing high amounts of macronutrients as N, P, K, S, Mg and Ca and this could make the chars most valuable as raw materials for fertilizer production. The sewage sludge waste bulk volume (the char compared to the sludge) was reduced with 52 % by pyrolysis at 575 deg. C. It is seen that the fast pyrolysis process provides a promising method to reduce cost for landfilling and produce a bio-oil that can be used as a fuel. The pyrolysis temperature has a considerable effect on the product distributions of the lignin and sewage sludge PCR pyrolysis, as well as their bio-oil properties with respect to molecular mass distribution, identified GC-MS component compositions, water-insoluble fraction, viscosity, and HHV. A maximum of organic oil yields of lignin and sewage sludge PCR pyrolysis were obtained at optimal temperatures of 550 - 575 deg. C. In this work, the behaviors of slurry samples of wood, char and grinded char with respect to phase transitions, rheological properties, elemental composition, and energy density were investigated. Also pumping properties were investigated at temperatures of 25, 40 and 60 deg. C and the solids loading of 0 - 20 wt%. The bioslurries obtained a volume energy density of 21-23 GJ/m{sup 3} and an energy densification factor of 4.5 - 5 (when compared to beech wood). Their apparent viscosities were significantly influenced by the solid loading levels (0 - 20 wt %) and temperatures (25 - 60 deg. C). The slurry samples with 10 wt% char (having d80 of 276 {mu}m) and 20 wt% grinded char (having d80 of 118 {mu}m) were successfully pumped into a pressurized chamber (0 - 6 bar). (LN)

Trinh, N.T.

2013-04-15

356

A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid  

Energy Technology Data Exchange (ETDEWEB)

An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

Arceo, Elena; Ellman, Jonathan; Bergman, Robert

2010-05-03

357

Homocoupling versus reduction of radicals: an experimental and theoretical study of Ti(iii)-mediated deoxygenation of activated alcohols.  

Science.gov (United States)

A detailed experimental and theoretical study corroborates that the reductive deoxygenation of activated (allylic or benzylic) alcohols with excess Ti(iii) proceeds via an allyl(benzyl)-radical and allyl(benzyl)-Ti, which is protonated, regioselectively in the case of allylic derivatives. The H atom of the newly formed C-H bond in the product originates from the -OH group of the starting material. The deoxygenation of lithium alkoxides or alcohols by using 1.0 mol of Ti(iii) leads to the corresponding dimerization products in good yields. An excellent agreement with the experimental data was obtained by using a reaction kinetics simulator to discriminate between competing reactions. PMID:25665946

Prieto, Consuelo; Gonzlez Delgado, Jos A; Arteaga, Jess F; Jaraz, Martn; Lpez-Prez, Jos L; Barrero, Alejandro F

2015-03-01

358

Flash pyrolysis fuel oil: bio-pok  

Energy Technology Data Exchange (ETDEWEB)

Samples of flash pyrolysis liquid produced by Union Fenosa, Spain from pine and straw and samples produced by Ensyn of Canada from mixed hardwoods were combusted with simple pressure atomization equipment commonly used with light fuel oils in intermediate size (0.1-1 MW) boilers. With a number of modifications to the combustion system, carbon monoxide (CO) and nitrous oxide (NO{sub x}) could be reduced to acceptable levels: CO < 30 ppm and NO{sub x} < 140 ppm. Particulate emissions which were initially very high (Bacharach 4-5) were reduced (Bach. 2-3) by system improvements but are still higher than from light fuel oil (Bach. <1). The modifications to the combustion system were: refractory section between burner and boiler, acid resistant progressive cavity pump, higher liquid preheat temperature and higher pressure than for light fuel oils. The main problems with pyrolysis liquids concerns their instability or reactivity. At temperatures above 100 deg C they begin to coke, their viscosity increases during storage and oxygen from air causes skin formation. This requires that special handling procedures are developed for fuel storage, delivery and combustion systems. (orig.)

Gust, S. [Neste Oy, Porvoo (Finland)

1997-12-01

359

A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed  

Science.gov (United States)

This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250300C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes. PMID:25656294

Sun, You-Hong; Bai, Feng-Tian; L, Xiao-Shu; Li, Qiang; Liu, Yu-Min; Guo, Ming-Yi; Guo, Wei; Liu, Bao-Chang

2015-01-01

360

A Novel Energy-Efficient Pyrolysis Process: Self-pyrolysis of Oil Shale Triggered by Topochemical Heat in a Horizontal Fixed Bed  

Science.gov (United States)

This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250-300C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes.

Sun, You-Hong; Bai, Feng-Tian; L, Xiao-Shu; Li, Qiang; Liu, Yu-Min; Guo, Ming-Yi; Guo, Wei; Liu, Bao-Chang

2015-02-01

361

Bio-oil from Flash Pyrolysis of Agricultural Residues  

DEFF Research Database (Denmark)

This thesis describes the production of bio-oils from flash pyrolysis of agricultural residues, using a pyrolysis centrifugal reactor (PCR). By thermal degradation of agricultural residues in the PCR, a liquid oil, char and non-condensable gases are produced. The yield of each fraction is influenced by the reaction temperature and by feedstock ash composition. It have been the objective of the present work to investigate the influence of changed operation conditions on the yield of bio-oil, char and gas; as well as to investigate the composition and storage properties of some of the produced bio-oils. Mainly the influence of feedstock type (wheat straw, rice husk and pine wood), feedstock water content and reactor temperature on the yield of char, bio-oil and gas were investigated. The storage stability of bio-oils with respect to changes in viscosity, water content and pH were investigated for straw and pine wood oil at different temperature and residence times. Temperature plays a major role in the pyrolysis process and it determines to a high degree the fate of the final product yields and also product composition. Higher temperature favors the formation of pyrolysis gas while lower temperatures increase the yield of char. Liquid oil, however increases with temperature up to certain point and thereafter it decreases at still higher temperature due to secondary cracking of the primary products. The presence of moisture in the feed stock may also influences the pyrolysis process. The influence of reaction temperature and the moisture content on the flash pyrolysis product yield has been reported in Paper I (Chapter 2). It was observed that the presence of moisture in the wheat straw with different moisture levels of 1.5 wt. %, 6.2 wt. % and 15.0 wt. % have shown no significant effect on the pyrolysis product distribution. The fraction of bio-oil, char and gases produced from pyrolysis of straw were in the range of 40-60 wt. %, 18-50 wt. % and 5-22 wt. %, respectively, regardless of the straw moisture levels. The optimal reaction temperature for the production of bio-oil was around 525 C to 550 C for all straw moisture contents. It was investigated how differences in biomass composition influence pyrolysis products yields and the composition of char and bio-oils. Details about this investigation are explained in Paper II (Chapter 3). The used pine wood had a low ash content (0.5 wt. %), the wheat straw an intermediate ash level (6.0 wt. %) and the rice husk a high ash level (13.6 wt. %). The highest alkali content, potassium (1.53 wt. %) are present in straw and the lowest potassium content level is observed in pine wood (0.04 wt. %). The feedstocks were pyrolyzed at reactor temperatures ranging from 475 to 575 oC. It was observed that the formation of char and gas is affected by the biomass alkali content. Increasing biomass alkali content caused an increased feedstock conversion at low temperature, a lower maximum liquid organic yield temperature and a lower maximum liquid organics yield. In addition, the chemical compositions of the bio-oils and the chars of the investigated feedstocks were also analyzed. The utilization of the pyrolysis oil in static combustion equipments such as boilers and turbine have shown that the suitability of the pyrolysis oil to substitute fossil fuel. However, several limitations still arise due to the instability of the pyrolysis oil that may cause problems with transport and storage. Pyrolysis oil contains more than hundred of chemical compounds and has a wide range of volatility (different boiling points). The stability and aging of bio-oils generated by bench scale pyrolysis of wheat straw and pine wood are discussed in Paper III (Chapter 4). It was found that the bio-oil from wheat straw shows better stability compared to the bio-oil from pine wood. In addition, both bio-oils are fairly stable stored in a closed container at room temperature for up to 130 days, with no phase separation and only small changes in physical properties were observed. The combustion behavior of pyrolysis

Ibrahim, Norazana

2012-01-01

362

Quantum mechanical analysis of oxygenated and deoxygenated states of hemocyanin: theoretical clues for a plausible allosteric model of oxygen binding.  

OpenAIRE

In this work with ab initio computations, we describe relevant interactions between protein active sites and ligands, using as a test case arthropod hemocyanins. A computational analysis of models corresponding to the oxygenated and deoxygenated forms of the hemocyanin active site is performed using the Density Functional Theory approach. We characterize the electron density distribution of the binding site with and without bound oxygen in relation to the geometry, which stems out of the crys...

Fariselli, P.; Bottoni, A.; Bernardi, F.; Casadio, R.

1999-01-01

363

Tuning the Selectivity in Deoxygenation of Triglycerides Aimed at the production of Renewable Feedstocks for Ethylene Production.  

Czech Academy of Sciences Publication Activity Database

Jerusalem : -, 2009, s. 424. ISBN N. [EuropaCat IX: "Catalysis for Sustainable World ". Salamanca (ES), 30.08.2009-04.09.2009] R&D Projects: GA MPO FT-TA3/074 Institutional research plan: CEZ:AV0Z40720504 Keywords : deoxygenation * NiMo catalysts * biofuel Subject RIV: CC - Organic Chemistry http://www.certh.gr/577CC7CC.en.aspx

Kubi?ka, D.; Hor?ek, J.; Kalua, Lud?k

364

Pyrolysis oil from carbonaceous solid wastes in Malaysia  

International Nuclear Information System (INIS)

The agro-industrial sector of Malaysia produces a huge amount of oil palm and paddy rice. These generate a significant amount of renewable biomass solid wastes in the forms of oil palm shell and rice husk. Apart from this a huge quantity of scrap tyre is generated from the country's faster increasing usage of transportation vehicles like motorcycle, car, bus and lorries. These wastes are producing pollution and disposal problems affecting the environment. Besides energy is not recovered efficiently from these waste resources. From the elemental composition and thermogravimetric analysis (TGA) studies of the wastes, it appeared that the wastes could be used for pyrolysis liquid oil production. Pyrolysis at present is deemed to be a potential method for the conversion of carbonaceous solid wastes into upgraded liquid products which can either be tried for liquid fuel or value-added chemical. A fluidized bed bench scale fast pyrolysis system was employed for this thermochemical conversion process of solid wastes. Silica sand was used as fluidized bed material and nitrogen gas as the fluidising medium. The products obtained were liquid oil, solid char and gas. The liquid oil and solid char were collected separately while the gas was flared. The maximum liquid product yield was found to vary with feedstock material fluidized bed temperature. The maximum liquid product yield was found to be 58, 53 and 40 wt. % of biomass fed at fluidized bed temperature at 500, 525 and 4500C respectively for oil palm shell, scrap tyre and rice husk. The solid char yield was 25, 36 and 53 wt. % of biomass fed at the condition of maximum liquid product yield for oil palm shell, scrap tyre and rice husk respectively. The oil products were subjected to FTIR, GC and GC/MS analysis for their group composition and detailed chemical compositions. The pyrolysis oil from scrap tyre was found to contain highest percentage of pure hydrocarbons (25 wt. % of total feed) with esters and oxygenated hydrocarbons containing silicone. The phenols were found to be maximum in case of oil palm shell pyrolysis oil (35 wt. % of total feed) with organic acids, alcohol, ketones and hydrocarbons. The pyrolysis oil from rice husk contained a maximum. percentage of ketones (28 wt. % of total feed) with acids, aldehydes, alcohol, phenols and hydrocarbons. Thus, the compounds were found to be prospectful for fuel and chemicals. The physical properties of the pyrolysis oils were presented and compared with typical wood pyrolysis oil. (Author)

365

Pyrolysis of phenols from lignite semicoking tar  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of phenols from lignite semicoking tar at 750-900 {degree}C and contact time of 0.5-6.0 s was studied. The yields of pyrocarbon, pyrolysis gas, and liquid products and the group and component composition of the liquid products and pyrolysis gas were determined. The main groups of compounds in liquid products were analysed.

Platonov, V.V.; Ryltsova, S.V.; Proskuryakov, V.A.; Rozental, D.A.; Polovetskaya, O.S.; Martynov, V.Y.; Chilachava, K.B.

2000-07-01

366

Bio-oil from flash pyrolysis of agricultural residues  

Energy Technology Data Exchange (ETDEWEB)

This thesis describes the production of bio-oils from flash pyrolysis of agricultural residues, using a pyrolysis centrifugal reactor (PCR). It has been the objective of the present work to investigate the influence of changed operation conditions on the yield of bio-oil, char and gas; as well as to investigate the composition and storage properties of some of the produced bio-oils. Mainly the influence of feedstock type (wheat straw, rice husk and pine wood), feedstock water content and reactor temperature on the yield of char, bio-oil and gas were investigated. The storage stability of bio-oils with respect to changes in viscosity, water content and pH were investigated for straw and pine wood oil at different temperature and residence times. Temperature plays a major role in the pyrolysis process and it determines to a high degree the fate of the final product yields and also product composition. Higher temperature favors the formation of pyrolysis gas while lower temperatures increase the yield of char. Liquid oil, however increases with temperature up to certain point and thereafter it decreases at still higher temperature due to secondary cracking of the primary products. The presence of moisture in the feed stock may also influences the pyrolysis process. The influence of reaction temperature and the moisture content on the flash pyrolysis product yield has been reported in Paper I (Chapter 2). It was observed that the presence of moisture in the wheat straw with different moisture levels of 1.5 wt. %, 6.2 wt. % and 15.0 wt. % have shown no significant effect on the pyrolysis product distribution. The fraction of bio-oil, char and gases produced from pyrolysis of straw were in the range of 40-60 wt. %, 18-50 wt. % and 5-22 wt. %, respectively, regardless of the straw moisture levels. The optimal reaction temperature for the production of bio-oil was around 525 deg. C to 550 deg. C for all straw moisture contents. It was investigated how differences in biomass composition influence pyrolysis products yields and the composition of char and bio-oils. Details about this investigation are explained in Paper II (Chapter 3). The used pine wood had a low ash content (0.5 wt. %), the wheat straw an intermediate ash level (6.0 wt. %) and the rice husk a high ash level (13.6 wt. %). The highest alkali content, potassium (1.53 wt. %) are present in straw and the lowest potassium content level is observed in pine wood (0.04 wt. %). The feedstocks were pyrolyzed at reactor temperatures ranging from 475 to 575 deg. C. It was observed that the formation of char and gas is affected by the biomass alkali content. Increasing biomass alkali content caused an increased feedstock conversion at low temperature, a lower maximum liquid organic yield temperature and a lower maximum liquid organics yield. In addition, the chemical compositions of the bio-oils and the chars of the investigated feedstocks were also analyzed. The utilization of the pyrolysis oil in static combustion equipments such as boilers and turbine have shown that the suitability of the pyrolysis oil to substitute fossil fuel. However, several limitations still arise due to the instability of the pyrolysis oil that may cause problems with transport and storage. Pyrolysis oil contains more than hundred of chemical compounds and has a wide range of volatility (different boiling points). The stability and aging of bio-oils generated by bench scale pyrolysis of wheat straw and pine wood are discussed in Paper III (Chapter 4). It was found that the bio-oil from wheat straw shows better stability compared to the bio-oil from pine wood. In addition, both bio-oils are fairly stable stored in a closed container at room temperature for up to 130 days, with no phase separation and only small changes in physical properties were observed. The combustion behavior of pyrolysis oils derived from wheat straw and pine wood are investigated and discussed in Paper IV (Chapter 5). The investigation is done in two parts. In the first part, the technique of thermogravimetric analysis (TGA) was

Ibrahim, N.B.

2012-08-15

367

Deactivation in Continuous Deoxygenation of C18-Fatty Feedstock over Pd/Sibunit  

DEFF Research Database (Denmark)

Catalytic continuous deoxygenation of stearic acid, ethyl stearate and tristearin without any solvents was investigated using Pd/Sibunit as a catalyst in a trickle bed reactor at 300 C. The main emphasis was to investigate the effect of gas atmosphere and catalyst deactivation. In addition to liquid-phase analysis made offline by GC, also online gas-phase analysis with IR were performed. The main liquid-phase product coming from all reactants was n-heptadecane. In addition to deoxygenation, which was observed for all substrates, also C18 and C16 alkanes were formed from tristearin. The relative ratios between stearic acid, ethyl stearate and tristearin conversions to alkanes after 3 days time-on-stream were 2.8/2.3/1.0, respectively using 5 % H2/Ar as a gas atmosphere, whereas rapid catalyst deactivation occurred with all substrates under H2-lacking atmosphere. The spent catalysts specific surface area profile along the downward reactor was maximum in the middle of the catalyst beds with the highest pore shrinking in the beginning and at the end of the reactor catalyst segments in the case of stearic acid and tristearin deoxygenation whereas that decreased consecutively as ethyl stearate passed through the reactor.

Madsen, Anders Theilgaard; Rozmys?owicz, Bartosz

2013-01-01

368

Pyrolysis characteristic of tobacco stem studied by Py-GC/MS, TG-FTIR, and TG-MS  

Directory of Open Access Journals (Sweden)

Full Text Available Pyrolysis characteristics and mechanism of tobacco stem were studied by pyrolysis coupled with gas chromatography/mass spectrometry (Py-GC/MS, thermogravimetric analyzer coupled with Fourier transform infrared spectrometry, and mass spectrometry (TG-FTIR and TG-MS techniques. The composition of evolved volatiles from fast pyrolysis of tobacco stem was determined by Py-GC/MS analysis, and the evolution patterns of the major products were investigated by TG-FTIR and TG-MS. Py-GC/MS data indicated that furfural and phenol were the major products in low temperature pyrolysis, and these were generated from depolymerization of cellulose. Indene and naphthalene were the major products in high temperature pyrolysis. TG-FTIR and TG-MS results showed that CO, CO2, phenols, aldehydes, and ketones were released between 167C and 500C; at temperatures >500C, CO and CO2 were the main gaseous products.

Bei Liu

2013-02-01

369

Pyrolysis of polyolefins for increasing the yield of monomers' recovery.  

Science.gov (United States)

Pyrolysis of plastic waste is an alternative way of plastic recovery and could be a potential solution for the increasing stream of solid waste. The objective of this work was to increase the yield the gaseous olefins (monomers) as feedstock for polymerization process and to test the applicability of a commercial Ziegler-Natta (Z-N): TiCl(4)/MgCl(2) for cracking a mixture of polyolefins consisted of 46%wt. of low density polyethylene (LDPE), 30%wt. of high density polyethylene (HDPE) and 24%wt. of polypropylene (PP). Two sets of experiments have been carried out at 500 and 650C via catalytic pyrolysis (1% of Z-N catalyst) and at 650 and 730C via only-thermal pyrolysis. These experiments have been conducted in a lab-scale, fluidized quartz-bed reactor of a capacity of 1-3kg/h at Hamburg University. The results revealed a strong influence of temperature and presence of catalyst on the product distribution. The ratios of gas/liquid/solid mass fractions via thermal pyrolysis were: 36.9/48.4/15.7%wt. and 42.4/44.7/13.9%wt. at 650 and 730C while via catalytic pyrolysis were: 6.5/89.0/4.5%wt. and 54.3/41.9/3.8%wt. at 500 and 650C, respectively. At 650C the monomer generation increased by 55% up to 23.6%wt. of total pyrolysis products distribution while the catalyst was added. Obtained yields of olefins were compared with the naphtha steam cracking process and other potentially attractive processes for feedstock generation. The concept of closed cycle material flow for polyolefins has been discussed, showing the potential benefits of feedstock recycling in a plastic waste management. PMID:22093704

Donaj, Pawel J; Kaminsky, W; Buzeto, F; Yang, W

2012-05-01

370

Finite element study of nonlinear two-dimensional deoxygenated biomagnetic micropolar flow  

Science.gov (United States)

In this paper, we consider the two-dimensional fully-developed steady, viscous hydrodynamic flow of a deoxygenated biomagnetic micropolar fluid, in an ( X, Y) coordinate system. The momentum conservation equations with zero-pressure gradient are extended to incorporate the X- and Y-components of the biomagnetic body force term with appropriate boundary conditions. The equations are non-dimensionalized using a set of transformations. A finite element solution is obtained to the resulting non-dimensional model and the effects of biomagnetic number ( NH), micropolar microinertia parameter ( B) and micropolar viscosity ratio parameter ( R) on the X- and Y-direction velocity profiles and micro-rotation ( N) is studied in detail. Translational velocities ( U, V) are seen to be reduced with an increase in micropolarity ( R) and also biomagnetic effects ( NH). Conversely the velocities are increased with a rise in microinertia parameter ( B). Several special cases, e.g. Newtonian biomagnetic physiological flow, are also discussed. The model finds applications in blood flow in biomedical device technology (e.g. oxygenators), hemodynamics under strong external magnetic fields, magnetic drug carrier analysis, etc.

Bhargava, R.; Bg, O. Anwar; Sharma, S.; Zueco, J.

2010-05-01

371

Preconversion catalytic deoxygenation of phenolic functional groups. Quarterly report, January 1--March 30, 1996  

Energy Technology Data Exchange (ETDEWEB)

Over the course of the studies on catalytic deoxygenation of phenolic residues in coal by carbon monoxide, the author performed preliminary investigations into the removal of other heteroatom groups. This report describes the attempted carbonylation of phenyl amido complexes. These studies resulted in the surprisingly facile formation of amidines. The amidine group is the nitrogen analog of carboxylic acids and esters. This functional group combines the properties of an azomethane-like C=N double bond with an amide-like C-N single bond. This group, like the related allyl (C-C-C), aza-allyl (C-N-C), and carboxylato (O-C-O) groups, form a number of transition metal derivatives, with both early and late transition metals. Various bonding modes of the amidino group have been reported. However, most isolated complexes have the amidino ligand as a chelating ligand or bridging two metals. This is due to the preference of amidines to bond via the nitrogen lone pairs, in contrast to the {eta}3 bonding observed in metal-allyl complexes. The experimental section of the paper describes the synthesis of platinum complexes, X-ray diffraction data for one Pt complex, and its reaction with carbon monoxide. Results are presented on the crystal and molecular structure of a platinum complex.

Kubiak, C.P.

1996-12-31

372

Catalytic oxidative pyrolysis of spent organic ion exchange resins from nuclear power plants  

International Nuclear Information System (INIS)

The spent IX resins from nuclear power reactors are highly active solid wastes generated during operations of nuclear reactors. Catalytic oxidative pyrolysis of these resins can lead to high volume reduction of these wastes. Low temperature pyrolysis of transition metal ion loaded IX resins in presence of nitrogen was carried out in order to optimize catalyst composition to achieve maximum weight reduction. Thermo gravimetric analysis of the pyrolysis residues was carried out in presence of air in order to compare the oxidative characteristics of transition metal oxide catalysts. Copper along with iron, chromium and nickel present in the spent IX resins gave the most efficient catalyst combination for catalytic and oxidative pyrolysis of the residues. During low temperature catalytic pyrolysis, 137Cesium volatility was estimated to be around 0.01% from cationic resins and around 0.1% from anionic resins. During oxidative pyrolysis at 700 degC, nearly 10 to 40% of 137Cesium was found to be released to off gases depending upon type of resin and catalyst loaded on to it. The oxidation of pyrolytic residues at 700 degC gave weight reduction of 15% for cationic resins and 93% for anionic resins. Catalytic oxidative pyrolysis is attractive for reducing weight and volume of spent cationic resins from PHWRs and VVERs. (author)

373

Characteristics of SnO2:F Thin Films Deposited by Ultrasonic Spray Pyrolysis: Effect of Water Content in Solution and Substrate Temperature  

Directory of Open Access Journals (Sweden)

Full Text Available Fluorine doped tin oxide, SnO2:F, thin films were deposited by ultrasonic chemical spray starting from tin chloride and hydrofluoric acid. The physical characteristics of the films as a function of both water content in the starting solution and substrate temperature were studied. The film structure was polycrystalline in all cases, showing that the intensity of (200 peak increased with the water content in the starting solution. The electrical resistivity decreased with the water content, reaching a minimum value, in the order of 8 10-4 ?cm, for films deposited at 450? from a starting solution with a water content of 10 ml per 100 ml of solution; further increase in water content increased the corresponding resistivity. Optical transmittances of SnO2:F films were high, in the order of 75%, and the band gap values oscillated around 3.9 eV. SEM analysis showed uniform surface morphologies with different geometries depending on the deposition conditions. Composition analysis showed a stoichiometric compound with a [Sn/O] ratio around 1:2 in all samples. The presence of F into the SnO2 lattice was detected, within 2 at % respect to Sn.

Mario A. Snchez-Garca

2012-10-01

374

Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace  

Energy Technology Data Exchange (ETDEWEB)

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation.

Shenker, J.

1995-11-01

375

Development of a high-performance, coal-fired power generating system with a pyrolysis gas and char-fired high-temperature furnace  

International Nuclear Information System (INIS)

A high-performance power system (HIPPS) is being developed. This system is a coal-fired, combined-cycle plant that will have an efficiency of at least 47 percent, based on the higher heating value of the fuel. The original emissions goal of the project was for NOx and SOx to each be below 0.15 lb/MMBtu. In the Phase 2 RFP this emissions goal was reduced to 0.06 lb/MMBtu. The ultimate goal of HIPPS is to have an all-coal-fueled system, but initial versions of the system are allowed up to 35 percent heat input from natural gas. Foster Wheeler Development Corporation is currently leading a team effort with AlliedSignal, Bechtel, Foster Wheeler Energy Corporation, Research-Cottrell, TRW and Westinghouse. Previous work on the project was also done by General Electric. The HIPPS plant will use a high-Temperature Advanced Furnace (HITAF) to achieve combined-cycle operation with coal as the primary fuel. The HITAF is an atmospheric-pressure, pulverized-fuel-fired boiler/air heater. The HITAF is used to heat air for the gas turbine and also to transfer heat to the steam cycle. its design and functions are very similar to conventional PC boilers. Some important differences, however, arise from the requirements of the combined cycle operation

376

Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high temperature furnace (HITAF)  

Energy Technology Data Exchange (ETDEWEB)

A concept for an advanced coal-fired combined-cycle power generating system is currently being developed. The first phase of this three-phase program consists of conducting the necessary research and development to define the system, evaluate the economic and technical feasibility of the concept, and prepare an R D plan to develop the concept further. Foster Wheeler Development Corporation is leading a team ofcompanies involved in this effort. The system proposed to meet these goals is a combined-cycle system where air for a gas turbine is indirectly heated to approximately 1800[degrees]F in furnaces fired with cool-derived fuels and then directly heated in a natural-gas-fired combustor up to about 2400[degrees]F. The system is based on a pyrolyzing process that converts the coal into a low-Btu fuel gas and char. The fuelgas is a relatively clean fuel, and it is fired to heat tube surfaces that are susceptible to corrosion and problems from ash deposition. In particular, the high-temperature air heater tubes, which will need tobe a ceramic material, will be located in a separate furnace or region of a furnace that is exposed to combustion products from the low-Btu fuel gas only. A simplified process flow diagram is shown.

1992-11-01

377

Pyrolysis of a waste from the grinding of scrap tyres  

International Nuclear Information System (INIS)

Highlights: ? The pyrolysis of reinforcing fibres obtained from scrap tyres has been studied. ? The results have been compared to scrap tyre granules. ? A higher temperature is needed for the total decomposition of the fibres. ? More compounds with heteroatoms (O, N) were found in the oil from the fibres. ? Chars from the fibres exhibit lower BET surface and mesopore volume. - Abstract: The fibres that are used to reinforce tyres can be recovered as a waste in the process of grinding of scrap tyres. In this paper beneficiation through pyrolysis is studied since the fibres are made up of polymers with a small amount of rubber because the latter is difficult to separate. The experiments were performed at three temperatures (400, 550 and 900 C) in a horizontal oven. The three products gas, oil and char obtained from the pyrolysis were investigated. The composition of the gas was analyzed by means of gas chromatography. The oil was studied by gas chromatography and infrared spectroscopy. The char porous structure was determined by N2 adsorption. In addition, the topography of the chars was studied by means of scanning electron microscopy (SEM). The products resulting from the pyrolysis of the fibres were compared with those obtained from scrap rubber.

378

The effect of aromatic hydrocarbons on catalytic pyrolysis of n-hexadecane  

Energy Technology Data Exchange (ETDEWEB)

The results of the effect of aromatic hydrocarbons (ArU) (benzene, naphthaline and phenantrene) on the catalytic pyrolysis of n-hexadecane are cited. With a 1 and 5 percent benzene content in the raw material and a pyrolysis temperature of 720 to 760 degrees the output of the basic products is essentially unchanged. The same quantities of naphthaline and phenantrene reduce the output of the pyrolysis gas and ethylene. Polycyclic aromatic hydrocarbons promote an increase in the output of coke during catalytic cracking to a substantially lesser degree than with thermal cracking.

Kreynina, G.P.; Adelson, S.V.; Yefremenko, T.P.

1983-01-01

379

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products  

Science.gov (United States)

A process of using fast pyrolysis in a carrier gas to convert a plastic waste feedstream having a mixed polymeric composition in a manner such that pyrolysis of a given polymer to its high value monomeric constituent occurs prior to pyrolysis of other plastic components therein comprising: selecting a first temperature program range to cause pyrolysis of said given polymer to its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and support for treating said feed streams with said catalyst to effect acid or base catalyzed reaction pathways to maximize yield or enhance separation of said high value monomeric constituent in said temperature program range; differentially heating said feed stream at a heat rate within the first temperature program range to provide differential pyrolysis for selective recovery of optimum quantities of the high value monomeric constituent prior to pyrolysis of other plastic components; separating the high value monomeric constituents; selecting a second higher temperature range to cause pyrolysis of a different high value monomeric constituent of said plastic waste and differentially heating the feedstream at the higher temperature program range to cause pyrolysis of the different high value monomeric constituent; and separating the different high value monomeric constituent. 83 figs.

Evans, R.J.; Chum, H.L.

1994-10-25

380

Methods and apparatuses for preparing upgraded pyrolysis oil  

Science.gov (United States)

Methods and apparatuses for preparing upgraded pyrolysis oil are provided herein. In an embodiment, a method of preparing upgraded pyrolysis oil includes providing a biomass-derived pyrolysis oil stream having an original oxygen content. The biomass-derived pyrolysis oil stream is hydrodeoxygenated under catalysis in the presence of hydrogen to form a hydrodeoxygenated pyrolysis oil stream comprising a cyclic paraffin component. At least a portion of the hydrodeoxygenated pyrolysis oil stream is dehydrogenated under catalysis to form the upgraded pyrolysis oil.

Brandvold, Timothy A; Baird, Lance Awender; Frey, Stanley Joseph

2013-10-01

381

Exploratory studies on fast pyrolysis oil upgrading  

OpenAIRE

Pyrolysis oil is a dark brown liquid which can be produced in high yield from different kind of biomass sources by means of fast pyrolysis. Pyrolysis oil is considered as a promising second generation energy carrier and may play an important role in the future of "biobased economies". The energy content of pyrolysis oil is approximately half of fossil crude. Just like for crude oil, further reprocessing is necessary to arranged pyrolysis oil as fuel in e.g. combustion engines. This thesis des...

Mahfud, Farchad Husein

2007-01-01

382

Bio-oil production from pyrolysis and steam pyrolysis of soybean-cake: product yields and composition  

Energy Technology Data Exchange (ETDEWEB)

The slow pyrolysis of soybean cake in a fixed-bed reactor was investigated under three different atmospheres: static, for determining the effects of pyrolysis temperature and particle size, nitrogen and steam. The liquid yield of 33.78% was attained at 550{sup o}C pyrolysis temperature and 200 Cm{sup 3}/min sweeping gas flow rate with the soybean oil cake samples having 0.850 < D{sub p} < 1.250 mm particle size. And the liquid yield reached a maximum value of 42.79% with a steam velocity of 1.3 cm/s. Column chromatography was used to characterize the liquid product, bio-oil. The aliphatic subtractions of the oils were then analyzed by GC/MS. FTIR and {sup 1}H-NMR spectra were used to determine structural analysis of pyrolysis oils and aromatic and polar subtractions. The H/C ratios and the structure analysis of the fractions obtained from the biocrudes show that the fractions are quite similar to currently utilized transport fuels. (author)

Putun, A.E.; Apaydin, E.; Putun, E. [Anadolu University, Eskisehir (Turkey). Dept. of Chemical Engineering

2002-07-01

383

Production, properties and utilisation of pyrolysis oil  

Energy Technology Data Exchange (ETDEWEB)

In this project VTT Energy co-ordinates the EU JOULE Project `Biofuel oil for power plants and boilers` supporting the development projects of Finnish enterprises, and participates in the Pyrolysis Project of IEA Bioenergy Agreement. Presently two pyrolysis devices with capacities of 150 g/h and 1 kg/h are used for the project. Hot gas filtering tests by using one ceramic candle equipment have been carried out with the 1 kg/h device for pyrolysis oil. The solids and alkali contents of the product oil were reduced clearly. Suitable conditions are being defined for continuous hot gas filtering. A PDU device of 20 kg/h is being commissioned. The main aim of the chemical characterisation of pyrolysis oil was to develop as simple a method as possible for differentiating pyrolysis oils and for finding correlations between the characteristics and behaviour of pyrolysis oils. Pyrolysis oils produced from various raw materials (hardwood, pine, straw) were analysed and compared with each other. VTT Energy participates in the pyrolysis network (EU/PYNE) of EU, the aim of which is to collect and disseminate research results of pyrolysis studies, i.e., through a journal with a wide circulation. VTT also participates in the pyrolysis activity of IEA (PYRA), the other partners being Great Britain, EU, Canada and the United States. I.e., quality criteria and improvement, occupational safety and pyrolysis kinetics are discussed in IEA/PYRA

Sipilae, K.; Oasmaa, A.; Arpiainen, V.; Solantausta, Y.; Leppaemaeki, E.; Kuoppala, E.; Levander, J.; Kleemola, J.; Saarimaeki, P. [VTT Energy, Jyvaeskylae (Finland). Energy Production Technologies

1997-12-01

384

Bio-oil production through pyrolysis of blue-green algae blooms (BGAB): Product distribution and bio-oil characterization  

International Nuclear Information System (INIS)

Pyrolysis experiments of blue-green algae blooms (BGAB) were carried out in a fixed-bed reactor to determine the effects of pyrolysis temperature, particle size and sweep gas flow rate on pyrolysis product yields and bio-oil properties. The pyrolysis temperature, particle size and sweep gas flow rate were varied in the ranges of 300700 C, below 0.252.5 mm and 50400 mL min?1, respectively. The maximum oil yield of 54.97% was obtained at a pyrolysis temperature of 500 C, particle size below 0.25 mm and sweep gas flow rate of 100 mL min?1. The elemental analysis and calorific value of the oil were determined, and the chemical composition of the oil was investigated using gas chromatographymass spectroscopy (GCMS) technique. The analysis of bio-oil composition showed that bio-oil from BGAB could be a potential source of renewable fuel with a heating value of 31.9 MJ kg?1. - Highlights: ? Bio-oil production from pyrolysis of blue-green algae blooms in fixed bed reactor. ? Effects of pyrolysis conditions on product distribution were investigated. ? The maximum bio-oil yield reached 54.97 wt %. ? The bio-oil has high heating value and may be suitable as renewable fuel. ? Pyrolysis of algal biomass beneficial for energy recovery, eutrophication control

385

Bio-oil production from fast pyrolysis of waste furniture sawdust in a fluidized bed.  

Science.gov (United States)

The amount of waste furniture generated in Korea was over 2.4 million tons in the past 3 years, which can be used for renewable energy or fuel feedstock production. Fast pyrolysis is available for thermo-chemical conversion of the waste wood mostly into bio-oil. In this work, fast pyrolysis of waste furniture sawdust was investigated under various reaction conditions (pyrolysis temperature, particle size, feed rate and flow rate of fluidizing medium) in a fluidized-bed reactor. The optimal pyrolysis temperature for increased yields of bio-oil was 450 degrees C. Excessively smaller or larger feed size negatively affected the production of bio-oil. Higher flow and feeding rates were more effective for the production of bio-oil, but did not greatly affect the bio-oil yields within the tested ranges. The use of product gas as the fluidizing medium had a potential for increased bio-oil yields. PMID:19560915

Heo, Hyeon Su; Park, Hyun Ju; Park, Young-Kwon; Ryu, Changkook; Suh, Dong Jin; Suh, Young-Woong; Yim, Jin-Heong; Kim, Seung-Soo

2010-01-01

386

Pyrolysis of hydrocarbons in hydrogen and deuterium plasma jets Pt. 1  

International Nuclear Information System (INIS)

The pyrolysis of methane in high temperature atmospheric pressure hydrogen and deuterium plasma jets has been studied. Product distributions at different temperatures and conversion levels have been determined. The highest value for acetylene formation selectivity found was around 90%, the rest being converted practically to ethylene. All the pyrolysis product components obtained in experiments carried out in deuterium plasma contained deuterium; this finding provided for the first time the experimental proof that pyrolysis reactions of methane in a hydrogen plasma jet are of the radical type and, additionally it proved that the components of the hydrogen plasma - hydrogen atoms and molecules - play a role also as reactants in hydrocarbon plasma pyrolysis. Reaction path schemes have been developed based on the deuterium distribution found in the reaction products. (author)

387

Making Activated Carbon by Wet Pressurized Pyrolysis  

Science.gov (United States)

A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb oxides of nitrogen.

Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

2006-01-01

388

UVC emitting phosphors obtained by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The broadband inter-configurational (4f{sup 1}5d{sup 1{yields}}4f{sup 2}) emission of Pr{sup 3+} doped in lanthanum orthophosphate (LaPO{sub 4}) and in calcium pyrophosphate (Ca{sub 2}P{sub 2}O{sub 7}) has been investigated under plasma excitation. The synthesis by spray pyrolysis at moderate temperature followed by a controlled annealing proves to be a very efficient way to produce good quality UVC emitting phosphor Ca{sub 1.92}Pr{sub 0.04}Na{sub 0.04}P{sub 2}O{sub 7} ({alpha} phase). The emission of this phosphor in the wavelength range 200-350 nm has been measured with a prototype device, which can be employed for anti-microbial testing. - Research Highlights: {yields} The Pr{sup 3+} doped orthophosphate and pyrophosphate were synthesized by spray pyrolysis. {yields} The dense particles present good quality UVC emitting (200-350 nm). {yields} The prototype device can be employed for anti-microbial testing.

Caiut, J.M.A., E-mail: jmacaiut@iq.unesp.b [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CEMES/CNRS-BP 94347, 31055 Toulouse Cedex 4 (France); Institute of Chemistry, UNESP-Universidade Estadual Paulista, CP 355, Araraquara-SP 14801-970 (Brazil); Lechevallier, S.; Dexpert-Ghys, J. [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CEMES/CNRS-BP 94347, 31055 Toulouse Cedex 4 (France); Caillier, B.; Guillot, Ph. [Diagnostic des Plasmas Hors Equilibre, Universite Jean Francois Champollion, place de Verdun, 81012 Albi Cedex 9 (France)

2011-04-15

389

Controlled air batch-pyrolysis incinerator  

International Nuclear Information System (INIS)

Ontario Hydro has operated since 1977 an incineration system for low-level radioactive wastes, located at the Bruce Nuclear Power Development site. The system utilizes a controlled air batch-pyrolysis technique, in which batches of waste are pyrolized in an oxygen deficient atmosphere. Gaseous pyrolysis products are fully oxidized in an afterburner. The original design of the incineration system did not meet the operational requirements in a number of areas: typically, the duration of the burn cycle was much longer than expected, affecting the system's overall waste processing capacity; the off-gas heat exchanger was found to be unsuitable for prolonged service under high temperature cyclic service; the bag filters were blinded frequently; and the primary chamber stainless steel inner liner was permanently deformed after only a few years of operation. Design changes have been carried out throughout the system during its operating life, which stabilized the system's performance. By the end of 1985, the system processed over 1,800 t of radioac