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1

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

UK PubMed Central (United Kingdom)

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 340°C 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.

Payormhorm J; Kangvansaichol K; Reubroycharoen P; Kuchonthara P; Hinchiranan N

2013-07-01

2

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 340°C 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

2013-04-15

3

Bio-oil deoxygenation by catalytic pyrolysis: new catalysts for the conversion of biomass into densified and deoxygenated bio-oil.  

UK PubMed Central (United Kingdom)

This work proposes an innovative catalytic pyrolysis process that converts bio-refinery residues, such as spent grains, into intermediate bio-oil with improved properties compared to traditional bio-oils, which allows the use of existing crude-oil refinery settings for bio-oil upgrading into fuels. The integration of bio-oil into a crude-oil refinery would decrease the economic disadvantage of biomass compared to fossil fuels. The catalytic pyrolysis was able to produce bio-oil with a lower O and N content and high levels of aliphatics and H by using activated serpentine and olivine at 430-460 °C. The activated materials seem to be beneficial to the bio-oil energy content by increasing it from less than 20 MJ kg(-1) in the original biomass to 26 MJ kg(-1). Approximately 70-74 % of the starting energy remains in the bio-oil using activated olivine (ACOL) and activated serpentine (ACSE) at 430 °C, whereas only 52 % is retained using alumina (ALU) at the same temperature. There was a strong reduction of the O content in the bio-oils, and the deoxygenation power decreased in the following order: ACOL>ACSE>ALU. In particular, ACOL at 430-460 °C was able to reduce the O content of the bio-oil by 40 %. The oxygenated bio-oil macromolecules interact in the catalyst's active sites with the naturally present metallic species and undergo decarboxylation with the formation of C(5)-C(6) O-depleted species.

Sanna A; Andrésen JM

2012-10-01

4

Alternative means of ambient temperature deoxygenation during unit startup or outage  

Energy Technology Data Exchange (ETDEWEB)

During normal operation of a fossil-fueled generating unit, the desired level of oxygen in high purity feedwater is determined by the mode of operation. For all volatile treatment (AVT), <1 ppb oxygen has been the goal, whereas for oxygenated treatment (OT), 50-200 ppb oxygen is typical. Regardless of the mode of normal operation, deoxygenated water is generally required during startup of a unit because of the presence of contaminants. In the absence of condensate or steam supplied by an on-line unit or an auxiliary boiler, oxygenated make-up water may be all that is immediately available to fill the boiler and/or pre-boiler system. Given the current trend towards increased cycling of units and more frequent cold plant start-ups, the requirement for rapid deoxygenation at ambient temperature is expected to increase, challenging those responsible for water treatment and chemical control to meet the need as economically as possible. Although there are a number of processes that can be used for deoxygenating makeup water, most of them require additional equipment (such as a vacuum deaerator or carbon bed) or extensive modifications of the existing demineralizer system (e.g., to allow use of sulfite form anion resin). In addition, distilled water storage tanks would need to be protected from reintroduction of oxygen. A simple, inexpensive, rapid, and flexible means of deoxygenation at ambient temperature that can be used as part of a makeup water system or to process deionized water in condensate tanks, boiler, or the deaerator storage tank would enable stations to deoxygenate as needed. Circumstances within the Southern California Edison (SCE) system forced us to look more critically at existing means of deoxygenation; our efforts resulted in the eventual development of the simple, inexpensive, rapid, and flexible ambient temperature deoxygenation process sought.

Cutler, F. [Southern California Edison Co., Paramount, CA (United States)

1995-01-01

5

High temperature pyrolysis of vinylacetylene  

Science.gov (United States)

The thermal decomposition of vinylacetylene has been studied behind reflected shock waves in the temperature range 1350-1870 K at total pressures between 1.7 and 7.4 bar. Initial concentrations of the hydrogen in argon ranged between 1 to 300 ppm. The following species were measured: H-atoms by ARAS, C2H2, C4H2 and C4H4 by molecular vuv-absorption. The combination of very low initial concentrations with a sensitive detection technique allowed to perform the experiments under conditions where only very few elementary reaction steps determine the progress of reaction. It was found that C4H4 decomposes simultaneously into different product channels: C4H4-->C2H2+C2H2 k1a=3.4.1013 exp(-38820/T) s-1 C4H4+Ar-->C4H3+H+Ar k1b=1.1.1020exp(-49990/T) cm3 mol-1 s-1 C4H4-->C4H2+H2 k1c=1.3.1015exp(-47670/T) s-1. From variation of the total pressure it has been deduced that reaction pathways R1a and R1c proceed with rates not far from the high-pressure limiting values and that reaction R1b proceeds close to the low-pressure limiting rate constant values.

Braun-Unkhoff, M.; Kurz, A.; Frank, P.

1990-07-01

6

Experimental study of rapid brown coal pyrolysis at high temperature  

Energy Technology Data Exchange (ETDEWEB)

Rapid coal pyrolysis is a very important step in the early stage of combustion. Rapid pyrolysis experiments of a brown coal at high temperature have been studied on a laminar drop tube furnace. The volatile mass release measured in this study is high for low rank coal. The activation energy and pre-exponential factor of pyrolysis are 19901.22 kJ/mol and 102.71, respectively. The nitrogen distribution between volatile and char is 0.54. With the increase of temperature, the yields of NH{sub 3} decreases, while those of HCN increases, leading the value of HCN/NH{sub 3} to become larger. At high temperature, the main nitrogen- containing species of pyrolysis in volatile is HCN.

Qian, Lin; Sun, Shaozeng; Meng, Shun; Meng, Xianyu; Guo, Yangzhou [Harbin Institute of Technology, Harbin (China). Combustion Engineering Research Inst.

2013-07-01

7

Pyrolysis and gasification of coal at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

We made considerable progress towards completing the development of a thermogravimetric reactor with video microscopy imaging capabilities (TGA/VMI). The video micrOSCOPY components were designed, installed and are currently under testing. With the newly developed TGA/VNH apparatus we can directly observe macroscopic changes in the morphology of pyrolyzing particles and thermal ignitions of burning particles while simultaneously monitoring the weight of pyrolyzing or reacting samples. The systematic investigation on the effects of pyrolysis conditions and char macropore structure on char reactivity continued. Pyrolysis and gasification experiments were performed consecutively in our TGA reactor and the char reactivity patterns were measured for a wide range of temperatures (400--600[degrees]C). These conditions cover both the kinetic and the diffusion limited regimes. Our results show conclusively that chars produced at high pyrolysis heating rates (and, therefore, having a more open cellular macropore structure) are more reactive and ignite more easily than chars pyrolyzed at low heating rates. These results have been explained using theoretical models. We also investigated for the first time the effect of coal particle size and external mass transfer limitations on the reactivity patterns and ignition behavior of char particles combusted in air. Finally, we used our hot stage reactor to monitor the structural transformations occurring during pyrolysis via a video microscopy system. Pyrolysis experiments were videotaped and particle swelling and the particle ignitions were determined and analyzed using digitized images from these experiments.

Zygourakis, K.

1990-01-01

8

High-temperature pyrolysis mechanisms of coal model compounds  

Energy Technology Data Exchange (ETDEWEB)

The degradation of the carboxylic acid group has been examined with respect to potential pretreatment strategies for fossil fuel conversion processes. In one potential pretreatment strategy involving cation exchange of the carboxylic acid group, a series of benzoic acid and stearic acid salts have been chosen to model the tight'' carboxylic acids of immature fossil fuel feedstocks and have been pyrolyzed with an entrained flow reactor. Our preliminary results indicate that Group I and II salts yield primarily the parent acid. Benzoate salts also yield small amounts of benzene while the stearic acid salts give no other detectable products. In two alternative treatment strategies, esterification and anhydride preparation have also been accomplished with these compounds being subjected to the entrained flow reactor conditions. The benzoate esters give a number of products, such as benzaldehyde, benzene, and low MW gases. The formation of these compounds is extremely dependent on pyrolysis conditions and alkoxy chain length. A xenon flashlamp and an entrained flow reactor have been used to heat organic substrates to varying temperatures using different heating rates. Ultrarapid flashlamp pyrolysis (heating rate>10{sup 50}C/s) has been performed. Since the ultrarapid pyrolysis products differ from those observed with traditional heating techniques and differ from the products formed photochemically, the flashlamp pyrolysis products are attributed to high temperature thermal activation.

Penn, J.H.; Owens, W.H.

1991-01-01

9

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 temperat...

Gang Li; Yuguang Zhou; Fang Ji; Ying Liu; Benu Adhikari; Li Tian; Zonghu Ma; Renjie Dong

10

Catalytic pyrolysis of tyres: influence of catalyst temperature  

Energy Technology Data Exchange (ETDEWEB)

Two stage pyrolysis catalysis of used tyres was undertaken to upgrade the derived oil to a highly aromatic oil suitable to be used as a chemical feedstock rather than a liquid fuel. The tyres were pyrolysed in a fixed bed reactor and the evolved pyrolysis gases were passed through a secondary fixed bed reactor containing zeolite catalyst. The pyrolysis reactor was maintained at 500{degree}C and the influence of catalyst temperature between 430 and 600{degree}C on the yield and composition of the derived oils was examined. Two zeolite catalysts were examined; a Y-type zeolite catalyst and zeolite ZSM-5 catalyst of differing pore size and surface activity. The influence of the catalyst was to reduce the yield of oil with a consequent increase in the gas yield and formation of coke on the catalyst. Single ring aromatic hydrocarbons, benzene, toluene and xylenes present in the oils showed a marked increase in the presence of the catalyst. Naphthalene and alkylated naphthalenes were also analysed and showed a similar marked increase in the concentration when a catalyst was present. The Y-type zeolite catalyst of larger pore size and higher surface activity was found to produce higher concentrations of aromatic compounds compared to the ZSM-5 catalyst. Increasing the catalyst temperature resulted in significant changes in the concentration of benzene, toluene, xylenes, naphthalene and the alkylated naphthalenes. 23 refs., 11 figs., 5 tabs.

Williams, P.T.; Brindle, A.J. [University of Leeds, Leeds (United Kingdom). Department of Fuel and Energy

2002-12-01

11

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

UK PubMed Central (United Kingdom)

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 525°C 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) 525°C 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.

Kloss S; Zehetner F; Dellantonio A; Hamid R; Ottner F; Liedtke V; Schwanninger M; Gerzabek MH; Soja G

2012-07-01

12

Hardfacing of high temperature alloys for ethylene pyrolysis applications  

Energy Technology Data Exchange (ETDEWEB)

Materials of construction in an ethylene pyrolysis furnace must withstand severe conditions including high temperatures, alternating oxidizing and carburizing atmospheres, impinging coke particles, and thermal cycling. The creep, high temperature corrosion, and erosion which are experienced by furnace components can be resisted by proper materials selection. Positioned directly in the process stream, thermowells are used to monitor process temperatures. Thermowell materials of construction must be selected with the extreme process conditions in mind. As always, safety is an underlying factor. Given the highly flammable ethylene stream, thermowell failures must be prevented at any cost. No single material was found to resist both creep and erosion under existing operating conditions. However, the combination of a creep resistant base material with a wear resistant coating was found to not only prevent failures, but also greatly extend thermowell life, reducing downtime and maintenance costs. Laboratory research and actual operations data have shown a nickel based superalloy with a ceramic hardfacing to be highly cost effective in thermowell applications in resisting the combination of creep and erosion found in ethylene pyrolysis applications.

Agosta, P.; Levesque, C.; Kurlekar, A. [Vista Chemical Co., Houston, TX (United States)

1994-12-31

13

Pyrolysis and gasification of coal at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

Coals of different ranks will be pyrolyzed in a microscope hot-stage reactor using inert and reacting atmosphere. The macropore structure of the produced chars will be characterized using video microscopy and digital image processing techniques to obtain pore size distributions. Comparative studies will quantify the effect of pyrolysis conditions (heating rates, final heat treatment temperatures, particle size and inert or reacting atmosphere) on the pore structure of the devolatilized chars. The devolatilized chars will be gasified in the regime of strong intraparticle diffusional limitations using O{sub 2}/N{sub 2} and O{sub 2}/H{sub 2}O/N{sub 2}2 mixtures. Constant temperature and programmed-temperature experiments in a TCA will be used for these studies. Additional gasification experiments performed in the hot-stage reactor will be videotaped and selected images will be analyzed to obtain quantitative data on particle shrinkage and fragmentation.

Zygourakis, K.

1989-01-01

14

Effect of pyrolysis temperature and heating rate on biochar obtained from pyrolysis of safflower seed press cake.  

UK PubMed Central (United Kingdom)

Biochar is carbon-rich product generated from biomass through pyrolysis. In this study, the effects of pyrolysis temperature and heating rate on the yield and physicochemical and morphological properties of biochars obtained from safflower seed press cake were investigated. The results showed that the biochar yield and quality depend principally on the applied temperature where pyrolysis at 600 °C leaves a biochar with higher fixed carbon content (80.70%) and percentage carbon (73.75%), and higher heating value (30.27 MJ kg(-1)) in comparison with the original feedstock (SPC) and low volatile matter content (9.80%). The biochars had low surface areas (1.89-4.23 m(2)/g) and contained predominantly aromatic compounds. The biochar could be used for the production of activated carbon, in fuel applications, and water purification processes.

Ang?n D

2013-01-01

15

Effect of pyrolysis temperature and heating rate on biochar obtained from pyrolysis of safflower seed press cake.  

Science.gov (United States)

Biochar is carbon-rich product generated from biomass through pyrolysis. In this study, the effects of pyrolysis temperature and heating rate on the yield and physicochemical and morphological properties of biochars obtained from safflower seed press cake were investigated. The results showed that the biochar yield and quality depend principally on the applied temperature where pyrolysis at 600 °C leaves a biochar with higher fixed carbon content (80.70%) and percentage carbon (73.75%), and higher heating value (30.27 MJ kg(-1)) in comparison with the original feedstock (SPC) and low volatile matter content (9.80%). The biochars had low surface areas (1.89-4.23 m(2)/g) and contained predominantly aromatic compounds. The biochar could be used for the production of activated carbon, in fuel applications, and water purification processes. PMID:23211485

Ang?n, Dilek

2012-11-08

16

The high-temperature pyrolysis of 1,3-hexachlorobutadiene  

Energy Technology Data Exchange (ETDEWEB)

Comprehensive product yield determinations from the high-temperature, gas-phase pyrolysis of 1,3-hexachlorobutadiene using two fused-silica tubular flow reactors are reported. The effects of reactor surface-area-to-volume (S/V) ratio were evaluated by conducting detailed product analyses with 0.1 cm i.d. and 1.0 cm i.d. reactors. Under low S/V ratio, initial decomposition was observed at 1,023 K with formation of tetrachlorovinylacetylene, tetrachloroethene, and carbon tetrachloride, and molecular chlorine. Hexachlorobenzene, C{sub 8}Cl{sub 8}(cy), and C{sub 12}Cl{sub 8}(cy) were also observed as products at higher temperatures. Under high S/V ratio, C{sub 2}Cl{sub 4} decomposition was initiated at 873 K. In addition to the products observed under low S/V ratio, C{sub 3}Cl{sub 4}, C{sub 5}Cl{sub 6}, C{sub 12}Cl{sub 10}, and C{sub 16}C{sub 10} were also observed. As in the case of C{sub 2} chlorinated hydrocarbons the authors have studied, organic product yields were higher for the low S/V ratio experiments. Previously published detailed pyrolysis mechanisms for trichloroethene and C{sub 2}Cl{sub 4} were used to provide predictions of the high-temperature reaction behavior of C{sub 4}Cl{sub 6}. Minor revisions of the C{sub 2}Cl{sub 4} model produced reasonable agreement with observed C{sub 4}Cl{sub 6} product distributions without compromising previous agreement with C{sub 2}Cl{sub 4} product distributions. The model predictions were in better agreement with product distributions obtained using the lower S/V ratio reactor. Plausible radical-molecule addition reactions leading to C{sub 2}Cl{sub 4}, C{sub 4}Cl{sub 4}, C{sub 6}Cl{sub 6} (cy), C{sub 8}Cl{sub 8} (cy), and C{sub 12}Cl{sub 8} (cy) formation were identified with the assistance of sensitivity analysis and production rate calculations.

Taylor, P.H.; Tirey, D.A.; Dellinger, B. [Univ. of Dayton, OH (United States)

1996-07-01

17

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.

Gang Li; Yuguang Zhou; Fang Ji; Ying Liu; Benu Adhikari; Li Tian; Zonghu Ma; Renjie Dong

2013-01-01

18

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

19

Acid-, water- and high-temperature-stable ruthenium complexes for the total catalytic deoxygenation of glycerol to propane.  

UK PubMed Central (United Kingdom)

The ruthenium aqua complexes [Ru(H(2)O)(2)(bipy)(2)](OTf)(2), [cis-Ru(6,6'-Cl(2)-bipy)(2)(OH(2))(2)](OTf)(2), [Ru(H(2)O)(2)(phen)(2)](OTf)(2), [Ru(H(2)O)(3)(2,2':6',2''-terpy)](OTf)(2) and [Ru(H(2)O)(3)(Phterpy)](OTf)(2) (bipy = 2,2'-bipyridine; OTf(-) = triflate; phen = phenanthroline; terpy = terpyridine; Phterpy = 4'-phenyl-2,2':6',2''-terpyridine) are water- and acid-stable catalysts for the hydrogenation of aldehydes and ketones in sulfolane solution. In the presence of HOS(O)(2)CF(3) (triflic acid) as a dehydration co-catalyst they directly convert 1,2-hexanediol to n-hexanol and hexane. The terpyridine complexes are stable and active as catalysts at temperatures > or = 250 degrees C and in either aqueous sulfolane solution or pure water convert glycerol into n-propanol and ultimately propane as the final reaction product in up to quantitative yield. For the terpy complexes the active catalyst is postulated to be a carbonyl species [(4'-R-2,2':6',2''-terpy)Ru(CO)(H(2)O)(2)](OTf)(2) (R = H, Ph) formed by the decarbonylation of aldehydes (hexanal for 1,2-hexanediol and 3-hydroxypropanal for glycerol) generated in the reaction mixture through acid-catalyzed dehydration. The structure of the dimeric complex [{(4'-phenyl-2,2':6',2''-terpy)Ru(CO)}(2)(mu-OCH(3))(2)](OTf)(2) has been determined by single crystal X-ray crystallography (Space group P1 (a = 8.2532(17); b = 12.858(3); c = 14.363(3) A; alpha = 64.38(3); beta = 77.26(3); gamma = 87.12(3) degrees, R = 4.36 %).

Taher D; Thibault ME; Di Mondo D; Jennings M; Schlaf M

2009-10-01

20

Acid-, water- and high-temperature-stable ruthenium complexes for the total catalytic deoxygenation of glycerol to propane.  

Science.gov (United States)

The ruthenium aqua complexes [Ru(H(2)O)(2)(bipy)(2)](OTf)(2), [cis-Ru(6,6'-Cl(2)-bipy)(2)(OH(2))(2)](OTf)(2), [Ru(H(2)O)(2)(phen)(2)](OTf)(2), [Ru(H(2)O)(3)(2,2':6',2''-terpy)](OTf)(2) and [Ru(H(2)O)(3)(Phterpy)](OTf)(2) (bipy = 2,2'-bipyridine; OTf(-) = triflate; phen = phenanthroline; terpy = terpyridine; Phterpy = 4'-phenyl-2,2':6',2''-terpyridine) are water- and acid-stable catalysts for the hydrogenation of aldehydes and ketones in sulfolane solution. In the presence of HOS(O)(2)CF(3) (triflic acid) as a dehydration co-catalyst they directly convert 1,2-hexanediol to n-hexanol and hexane. The terpyridine complexes are stable and active as catalysts at temperatures > or = 250 degrees C and in either aqueous sulfolane solution or pure water convert glycerol into n-propanol and ultimately propane as the final reaction product in up to quantitative yield. For the terpy complexes the active catalyst is postulated to be a carbonyl species [(4'-R-2,2':6',2''-terpy)Ru(CO)(H(2)O)(2)](OTf)(2) (R = H, Ph) formed by the decarbonylation of aldehydes (hexanal for 1,2-hexanediol and 3-hydroxypropanal for glycerol) generated in the reaction mixture through acid-catalyzed dehydration. The structure of the dimeric complex [{(4'-phenyl-2,2':6',2''-terpy)Ru(CO)}(2)(mu-OCH(3))(2)](OTf)(2) has been determined by single crystal X-ray crystallography (Space group P1 (a = 8.2532(17); b = 12.858(3); c = 14.363(3) A; alpha = 64.38(3); beta = 77.26(3); gamma = 87.12(3) degrees, R = 4.36 %). PMID:19693757

Taher, Deeb; Thibault, Michelle E; Di Mondo, Domenico; Jennings, Michael; Schlaf, Marcel

2009-10-01

 
 
 
 
21

Pyrolysis of holm-oak wood: influence of temperature and particle size  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis of holm-oak wood sawdust was studied to determine the characteristics of the charcoal and the nature and amounts of gases produced. The temperature was varied from 300 to 900 degrees C and the wood particle size from 0.40 to 2 mm diameter. The fixed carbon content of the charcoal increased with temperature up to 700 degrees C, and then remained essentially constant. The gases produced were mainly CO, CO{sub 2}, H{sub 2} and CH{sub 4}. The rate constants and activation energies for the production of each gas were calculated assuming first order kinetics. The composition of the pyrolysis gas produced at each temperature was determined, and its heating value was calculated. Taking into consideration the quality of the charcoal and the heating value of the gases produced, it can be concluded that the optimal pyrolysis temperature is about 600 degrees C. 16 refs., 4 figs., 4 tabs.

Figueiredo, J.L.; Valenzuela, C.; Bernalte, A.; Encinar, J.M. (Centro de Engenharia Quimica (INIC), Porto (Portugal))

1989-08-01

22

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

Directory of Open Access Journals (Sweden)

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

Anchan Paethanom; Kunio Yoshikawa

2012-01-01

23

Shock tube, laser-Schlieren study of propane pyrolysis at high temperature  

Energy Technology Data Exchange (ETDEWEB)

This work was to provide an improved high temperature mechanism for propane pyrolysis, in particular a more precise rate for the initiation reaction: C/sub 3/H/sub 8/ ..-->.. C/sub 2/H/sub 5/+CH/sub 3/. Also the temperature range over which this rate has been measured was extended thus enabling the study of the falloff from the high pressure limit unimolecular rate constant. Initiation reaction rate constants for propane pyrolysis to 2300/sup 0/K. Results of k/sub 1/ show a clear pressure dependence above 1800/sup 0/K, the reaction being near second order in this range. (DP)

Al-Alami, M.Z.

1982-01-01

24

A reactive molecular dynamics study of n-heptane pyrolysis at high temperature.  

UK PubMed Central (United Kingdom)

n-Heptane is the most important straight chain paraffin in the fossil-fuel industry. In this work, pyrolysis of n-heptane at high temperature is investigated by a series of ReaxFF based reactive molecular dynamic simulations. The pyrolysis correlated intermediate reactions, important product/intermediate distributions, and corresponding kinetics behaviors are systematically analyzed at atomistic level. The results indicate that the entire pyrolysis process is radical-dominated. The unimolecular dissociation is the main pathway of n-heptane decomposition. Initiation of the decomposition is mainly through C-C bond fission. Central C-C bonds would dissociate prior to the terminal ones. Besides, the Rice-Kossiakoff theory is proved for the pyrolysis of n-heptane at the atomistic level. To give a better description of the pyrolysis behavior, some alkane related intermolecular reactions should be considered in the mechanism. The apparent activation energy extracted from the present simulations is 43.02-54.49 kcal/mol in the temperature range 2400-3000 K, which is reasonably consistent with the experimental results.

Ding J; Zhang L; Zhang Y; Han KL

2013-04-01

25

A reactive molecular dynamics study of n-heptane pyrolysis at high temperature.  

Science.gov (United States)

n-Heptane is the most important straight chain paraffin in the fossil-fuel industry. In this work, pyrolysis of n-heptane at high temperature is investigated by a series of ReaxFF based reactive molecular dynamic simulations. The pyrolysis correlated intermediate reactions, important product/intermediate distributions, and corresponding kinetics behaviors are systematically analyzed at atomistic level. The results indicate that the entire pyrolysis process is radical-dominated. The unimolecular dissociation is the main pathway of n-heptane decomposition. Initiation of the decomposition is mainly through C-C bond fission. Central C-C bonds would dissociate prior to the terminal ones. Besides, the Rice-Kossiakoff theory is proved for the pyrolysis of n-heptane at the atomistic level. To give a better description of the pyrolysis behavior, some alkane related intermolecular reactions should be considered in the mechanism. The apparent activation energy extracted from the present simulations is 43.02-54.49 kcal/mol in the temperature range 2400-3000 K, which is reasonably consistent with the experimental results. PMID:23544797

Ding, Junxia; Zhang, Liang; Zhang, Yan; Han, Ke-Li

2013-04-16

26

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; Gilberto Alves Romeiro; Raquel Vieira Santana Silva; Priscila Alvares Pinto; Raimundo Nonato Damasceno; Luiz Antonio d`Avila; Amanda P. Franco

2011-01-01

27

Statistical and steric effects on pyrene pyrolysis product distribution at high temperature  

Energy Technology Data Exchange (ETDEWEB)

Two sets of isomer products of pyrene pyrolysis at high temperatures are the six bipyrenes and their five cyclodehydrogenation products. Thermodynamic distributions of these isomer sets were computed using the AM1 semiempirical molecular model. Two properties of molecular structure, symmetry and steric hindrance associated with bonding between pyrene units, were found to govern these thermodynamic distributions. Distributions produced by pyrene pyrolysis, on the other hand, support a simple kinetic model of aryl addition and cyclodehydrogenation pathways in which reaction path degeneracy is a first-order effect and steric hindrance is of secondary importance. 10 refs., 4 figs., 2 tabs.

Mulholland, J.A.; Mukherjee, J.; Sarofim, A.F. [Georgia Institute of Technology, Atlanta, GA (United States). Environmental Engineering

1997-03-01

28

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

29

Influence of the Pyrolysis Temperature on Sewage Sludge Product Distribution, Bio-Oil, and Char Properties  

DEFF Research Database (Denmark)

Fast pyrolysis may be used for sewage sludge treatment with the advantages of a significant reduction of solid waste volume and production of a bio-oil that can be used as fuel. A study of the influence of the reaction temperature on sewage sludge pyrolysis has been carried out using a pyrolysis centrifugel reactor (PCR) at 475, 525, 575, and 625 °C. Maxima of both organic oil yield of 41 wt % on a dry ash free feedstock basis (daf) and a sludge oil energy recovery of 50% were obtained at 575 °C. The water-insoluble fraction, molecular-weight distribution, higher heating value (HHV), and thermal behaviors of sludge oils were found to be considerably influenced by the applied pyrolysis temperatures. The sludge oil properties obtained at the optimal temperature of 575 °C were a HHV of 25.5 MJ/kg, a water-insoluble fraction of 18.7 wt %, a viscosity of 43.6 mPa s at 40 °C, a mean molecular weight of 392 g/mol, and metal concentrations lower than 0.14 wt % on a dry basis (db). Less optimal oil properties with respect to industrial applications were observed for oil samples obtained at 475 and 625 °C. Char properties of the 575 °C sample were an ash content of 81 wt % and a HHV of 6.1 MJ/kg db. A total of 95% of the sewage sludge phosphorus content was recovered in the char. The solid waste amount (char compared to sludge) was reduced to 52% on a bulk volume basis at the pyrolysis temperature of 575 °C.

Trinh, Ngoc Trung; Jensen, Peter Arendt

2013-01-01

30

High-temperature pyrolysis mechanisms of coal model compounds. 1990 annual report  

Energy Technology Data Exchange (ETDEWEB)

The degradation of the carboxylic acid group has been examined with respect to potential pretreatment strategies for fossil fuel conversion processes. In one potential pretreatment strategy involving cation exchange of the carboxylic acid group, a series of benzoic acid and stearic acid salts have been chosen to model the ``tight`` carboxylic acids of immature fossil fuel feedstocks and have been pyrolyzed with an entrained flow reactor. Our preliminary results indicate that Group I and II salts yield primarily the parent acid. Benzoate salts also yield small amounts of benzene while the stearic acid salts give no other detectable products. In two alternative treatment strategies, esterification and anhydride preparation have also been accomplished with these compounds being subjected to the entrained flow reactor conditions. The benzoate esters give a number of products, such as benzaldehyde, benzene, and low MW gases. The formation of these compounds is extremely dependent on pyrolysis conditions and alkoxy chain length. A xenon flashlamp and an entrained flow reactor have been used to heat organic substrates to varying temperatures using different heating rates. Ultrarapid flashlamp pyrolysis (heating rate>10{sup 50}C/s) has been performed. Since the ultrarapid pyrolysis products differ from those observed with traditional heating techniques and differ from the products formed photochemically, the flashlamp pyrolysis products are attributed to high temperature thermal activation.

Penn, J.H.; Owens, W.H.

1991-01-01

31

Study of the kinetics of high-temperature wood pyrolysis in a thermobalance. Pt. 2. Experimental results and modelling of the pyrolysis of small oak cylinders  

Energy Technology Data Exchange (ETDEWEB)

Results show that the time needed for the total pyrolysis varies linearly with the cylinder diameter when this is lower than 3.4 mm. For higher values of the diameter, the total pyrolysis becomes a parabolic function of the diameter. As for sawdust, the cylinder pyrolysis occurs entirely during the heating period. A theoretical model has been developed. It is based on the assumptions of the shrinking-core model but it is considered that there exists competition between the chemical conversion rate and the heat conduction rate through the charcoal layer which is produced. The unreacted core is assumed to be at a uniform temperature. This model permits us to predict satisfactorily the time-variation of the pyrolysis rate. It also shows that the pyrolysis occurs mainly between 400 and 500/sup 0/C. In the case of small cylinders of less than 4,0 x 10/sup -3/ m in diameter, the model can be simplified by neglecting the resistance offered to the heat conduction through the charcoal layer.

Hemati, M.; Laguerie, C.

1987-07-15

32

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  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Monique Kort-Kamp Figueiredo; Gilberto Alves Romeiro; Raquel Vieira Santana Silva; Priscila Alvares Pinto; Raimundo Nonato Damasceno

33

Influence of temperature and particle size on the fixed bed pyrolysis of orange peel residues  

Energy Technology Data Exchange (ETDEWEB)

Orange peel is a residue from the production of juice. Its energetic valorisation could be interesting in areas where a different use, such as animal feed, is not possible. In order to investigate the viability of energy recovery, the pyrolysis of orange peel residues was studied in a fixed bed reactor, as an initial assessment of this process. The influence of pyrolysis temperature (300-600 C) and particle size (d{sub p}<300{mu}m and d{sub p}>800{mu}m) on product distribution, gas composition and char heating value has been investigated using a factorial design of experiments. Gas, char and water are the main products obtained; tar is only about 6 wt.% of the initial residue. Temperature was found to be the parameter which exerts a more important influence on the results than particle size. (author)

Aguiar, L. [Departamento de Mecanica, Universidad de Pinar del Rio, Cuba. Calle Marti 270, final, Pinar del Rio (Cuba); Marquez-Montesinos, F. [Departamento de Quimica, Universidad de Pinar del Rio, Cuba. Calle Marti 270, final, Pinar del Rio (Cuba); Gonzalo, A.; Sanchez, J.L.; Arauzo, J. [Thermochemical Processes Group (GPT), Aragon Institute for Engineering Research (I3A), University of Zaragoza, Maria de Luna 3, 50018 Zaragoza (Spain)

2008-09-15

34

Effective and chemical free deoxygenation of water  

Energy Technology Data Exchange (ETDEWEB)

Minox Technology has developed a system to remove oxygen from seawater in enhanced oil recovery operations. The Minox Deoxygenation System has been successfully used for the past 20 years to effectively remove oxygen from fluids without the use of chemicals. This paper described the process, plant build up, construction and performance features. The system is based on stripping dissolved oxygen from water with a closed loop circulating nitrogen gas, in which the oxygen is removed in a low temperature catalytic process. The greatest advantages of the Minox Deoxygenation System include: weight savings; space savings; greater flexibility in plant lay-out; chemical-free process; and, regeneration of stripping gas. The main components of the Ultra Compact Minox 2-stage edition are: compressors that are circulating gas; static mixers; separators; de-oxidizers; a methanol unit; a heat exchanger; and a heater. The Minox Compact Tower system, an alternative to the ultra Compact Minox 2-stage edition, makes it possible to obtain a 30 per cent increase of water flow through the tower and bring the residual oxygen content down to 20 ppb or less without applying a scavenger. It also reduces energy consumption. refs., tabs., figs.

Pedersen, D. [Ionics RCC, Watertown, MA (United States); Ulleberg, H. [Minox Technology, Notodden (Norway)

2004-07-01

35

Transport of biochar particles in saturated granular media: effects of pyrolysis temperature and particle size.  

UK PubMed Central (United Kingdom)

Land application of biochar is increasingly being considered for potential agronomic and environmental benefits, e.g., enhancing carbon sequestration, nutrient retention, water holding capacity, and crop productivity; and reducing greenhouse gas emissions and bioavailability of environmental contaminants. However, little is known about the transport of biochar particles in the aqueous environment, which represents a critical knowledge gap because biochar particles can facilitate the transport of adsorbed contaminants. In this study, column experiments were conducted to investigate biochar particle transport and retention in water-saturated quartz sand. Specific factors considered included biochar feedstocks (wheat straw and pine needle), pyrolysis temperature (350 and 550 °C), and particle size (micrometer-particle (MP) and nanoparticle (NP)). Greater mobility was observed for the biochars of lower pyrolysis temperatures and smaller particle sizes. Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) calculations that considered measured zeta potentials and Lewis acid-base interactions were used to better understand the influence of pyrolysis temperature on biochars particle transport. Most biochars exhibited attractive acid-base interactions that impeded their transport, whereas the biochar with the greatest mobility had repulsive acid-base interaction. Nonetheless, greater retention of the MPs than that of the NPs was in contrast with the XDLVO predictions. Straining and biochar surface charge heterogeneity were found to enhance the retention of biochar MPs, but played an insignificant role in the biochar NP retention. Experimental breakthrough curves and retention profiles were well-described using a two-site kinetic retention model that accounted for depth-dependent retention at one site. Modeled first-order retention coefficients on both sites 1 and 2 increased with increasing pyrolysis temperature and particle size.

Wang D; Zhang W; Hao X; Zhou D

2013-01-01

36

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 Lédé

2010-01-01

37

Influence of pyrolysis temperature on composted sewage sludge biochar priming effect in a loamy soil.  

Science.gov (United States)

Biochar is a carbon-rich solid product obtained by the pyrolysis of organic materials. The carbon stability of biochar allows that it can be applied to soil for long-term carbon storage. This carbon stability is greatly influenced by the pyrolysis temperature and the raw material used for biochar production. The aim of the present work is to study the soil carbon sequestration after the application of biochar from sewage sludge (SL) pyrolysis at two different temperatures (400 and 600°C). For this purpose, soil CO2 emissions were measured for 80d in an incubation experiment after soil amendment with the SL and each biochar at a dosage of 8wt%. Biochar reduced the CO2 emissions during incubation between 11% and 32% relative to the SL treatment. The CO2 data were fit to a dual exponential model, and the CO2 emissions were simulated at different times (1, 5 and 10yr). Additionally, the kinetics of the CO2 evolution from SL, two biochar samples, soil and amended soil were well fit to a dual first-order kinetic model with correlation coefficients greater than 0.93. The simulation of CO2 emissions from the soil by applying the proposed double first-order kinetic model (kg CO2Cha(-1)) showed a reduction of CO2 emissions between 301 and 932kg CO2Cha(-1)with respect to the direct application of raw sewage sludge after 10yr. PMID:23891257

Méndez, A; Tarquis, A M; Saa-Requejo, A; Guerrero, F; Gascó, G

2013-07-25

38

Influence of pyrolysis temperature on composted sewage sludge biochar priming effect in a loamy soil.  

UK PubMed Central (United Kingdom)

Biochar is a carbon-rich solid product obtained by the pyrolysis of organic materials. The carbon stability of biochar allows that it can be applied to soil for long-term carbon storage. This carbon stability is greatly influenced by the pyrolysis temperature and the raw material used for biochar production. The aim of the present work is to study the soil carbon sequestration after the application of biochar from sewage sludge (SL) pyrolysis at two different temperatures (400 and 600°C). For this purpose, soil CO2 emissions were measured for 80d in an incubation experiment after soil amendment with the SL and each biochar at a dosage of 8wt%. Biochar reduced the CO2 emissions during incubation between 11% and 32% relative to the SL treatment. The CO2 data were fit to a dual exponential model, and the CO2 emissions were simulated at different times (1, 5 and 10yr). Additionally, the kinetics of the CO2 evolution from SL, two biochar samples, soil and amended soil were well fit to a dual first-order kinetic model with correlation coefficients greater than 0.93. The simulation of CO2 emissions from the soil by applying the proposed double first-order kinetic model (kg CO2Cha(-1)) showed a reduction of CO2 emissions between 301 and 932kg CO2Cha(-1)with respect to the direct application of raw sewage sludge after 10yr.

Méndez A; Tarquis AM; Saa-Requejo A; Guerrero F; Gascó G

2013-10-01

39

Biomass-based pyrolytic polygeneration system on cotton stalk pyrolysis: influence of temperature.  

Science.gov (United States)

To study the process of biomass-based pyrolytic polygeneration and its mechanism in depth, the pyrolysis of cotton stalk was investigated in a packed bed, with focus on the evolution of the chemical and physical structures of the solid, liquid and gaseous products. The evolution of product characteristics could be good explaining the process mechanism of biomass pyrolysis. A relationship between the pore distribution of solid products and the fused aromatic rings system revealed by Raman analysis might be exist and need to quantify in further study. Regarding the optimum conditions for obtaining high-quality pyrolytic products from the polygeneration system, the optimum temperature is 550-750°C, with a higher calorific value of the obtained charcoal (? 28 MJ/kg) and a higher surface area (>200 m(2)/g). Meanwhile, the calorific value of the gas reaches 8-9 MJ/m(3) and the liquid oil would be used as a platform product in biorefinery. PMID:22209443

Chen, Yingquan; Yang, Haiping; Wang, Xianhua; Zhang, Shihong; Chen, Hanping

2011-11-06

40

Biomass-based pyrolytic polygeneration system on cotton stalk pyrolysis: influence of temperature.  

UK PubMed Central (United Kingdom)

To study the process of biomass-based pyrolytic polygeneration and its mechanism in depth, the pyrolysis of cotton stalk was investigated in a packed bed, with focus on the evolution of the chemical and physical structures of the solid, liquid and gaseous products. The evolution of product characteristics could be good explaining the process mechanism of biomass pyrolysis. A relationship between the pore distribution of solid products and the fused aromatic rings system revealed by Raman analysis might be exist and need to quantify in further study. Regarding the optimum conditions for obtaining high-quality pyrolytic products from the polygeneration system, the optimum temperature is 550-750°C, with a higher calorific value of the obtained charcoal (? 28 MJ/kg) and a higher surface area (>200 m(2)/g). Meanwhile, the calorific value of the gas reaches 8-9 MJ/m(3) and the liquid oil would be used as a platform product in biorefinery.

Chen Y; Yang H; Wang X; Zhang S; Chen H

2012-03-01

 
 
 
 
41

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

UK PubMed Central (United Kingdom)

Conocarpus wastes were pyrolyzed at different temperatures (200–800 °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.

Al-Wabel MI; Al-Omran A; El-Naggar AH; Nadeem M; Usman AR

2013-03-01

42

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 (200–800 °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

2013-01-08

43

Fuel and fuel blending components from biomass derived pyrolysis oil  

Energy Technology Data Exchange (ETDEWEB)

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

44

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...

45

Toluene pyrolysis studies and high temperature reactions of propargyl chloride  

Energy Technology Data Exchange (ETDEWEB)

The main focus of this program is to investigate the thermal decompositions of fuels that play an important role in the pre-particle soot formation process. It has been demonstrated that the condition of maximum soot yield is established when the reaction conditions of temperature and pressure are sufficient to establish a radical pool to support the production of polyaromatic hydrocarbon species and the subsequent formation of soot particles. However, elevated temperatures result in lower soot yields which are attributed to thermolyses of aromatic ring structures and result in the bell-shaped dependence of soot yield on temperature. The authors have selected several acyclic hydrocarbons to evaluate the chemical thermodynamic and kinetic effects attendant to benzene formation. To assess the thermal stability of the aromatic ring, the authors have studied the pyrolyses of benzene, toluene, ethylbenzene, chlorobenzene and pyridine. Time-of-flight mass spectrometry (TOF) is employed to analyze the reaction zone behind reflected shock waves. Reaction time histories of the reactants, products, and intermediates are constructed and mechanisms are formulated to model the experimental data. The TOF work is often performed with use of laser schlieren densitometry (LS) to measure density gradients resulting from the heats of various reactions involved in a particular pyrolytic system. The two techniques, TOF and LS, provide independent and complementary information about ring formation and ring rupture reactions.

Kern, R.D.; Chen, H.; Qin, Z. [Univ. of New Orleans, LA (United States)

1993-12-01

46

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.

1994-01-01

47

The role of temperature in the fast pyrolysis of cellulose and wood  

Energy Technology Data Exchange (ETDEWEB)

Cellulose and maple sawdust have been pyrolyzed by different workers in two different reactors (a fluid bed and a transport reactor) in separate laboratories. The Avicel cellulose sample used by both groups was from the same batch, while the maple was different samples of the same species. Fast pyrolysis product yields were compared at a constant vapor residence time of 500 ms over a temperature range of 450-900/sup 0/C and were found to be in very good agreement. It is proposed that if particle heat-up time to 500/sup 0/C, for any reactor, is significantly less than particle residence time, or if particle weight loss is less than 10% before the particle temperature reaches 450/sup 0/C, then the temperature of the reactor will be the only variable determining the yields of char, oil, and gases for a given feed material and a given gas residence time. The implications of the results in terms of product yields and possible pyrolysis mechanisms are discussed. The oil yield as temperature increases can be described adequately by a simple kinetic model.

Scott, D.S.; Piskorz, J.; Bergougnou, M.A.; Graham, R.; Overend, R.P.

1988-01-01

48

Effect of Pyrolysis Temperature on Properties of Porous Si3N4-BN Composites Fabricated Via PIP Route  

Science.gov (United States)

The Si3N4-BN composites have been prepared via die pressing and the precursor infiltration and pyrolysis route using borazine as the precursor. The Si3N4-BN composites are composed of h-BN, ?-Si3N4, and ?-Si3N4 produced at a pyrolysis temperature from 1200 to 1750 °C with only 0.17-3.9 wt.% phase transition of Si3N4. The effect of pyrolysis temperature on properties of the composites has been investigated. The density and mechanical properties of the composites, at both room temperature and 1000 °C, increase along with the elevating of the pyrolysis temperature. The density of the composites achieves 2.33 g/cm3 at 1750 °C with the porosity of 14.1%. The flexural strength, elastic modulus, and fracture toughness at room temperature of the Si3N4-BN composites pyrolyzed at 1750 °C are 219.1 MPa, 75.5 GPa, and 2.62 MPa m1/2, respectively. A desirable flexural strength of 184.9 MPa with a residual ratio of 84.4% has been obtained when the composites are exposed at 1000 °C in the air. Micrographs of SEM and TEM illustrate the bonding structure of the pyrolysis BN and Si3N4 grains.

Liu, Kun; Zhang, Changrui; Li, Bin; Wang, Siqing; Cao, Feng

2013-08-01

49

A method for isolating high temperature organic heat carriers from the bottoms of benzene pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

A method is proposed for isolating high temperature organic heat carriers (VT) from the bottoms from benzene pyrolysis with the use of multistaged rectification, which includes first stage isolation of a distillate of a fraction which contains diphenyl, o-terphenyl, m-terphenyl and p-terphenyl, with subsequent isolation from it of the terphenyl mixtures and industrial terphenyls. In order to simplify the technology of the process and to fully use the bottoms of benzene pyrolysis, the latter is subjected to three stage vacuum rectification with removal of the first stage at a temperature of 290 to 300 degrees and a vacuum of 100 to 105 millimeters as the bottom product of the fraction, which contains m-terphenyl, p-terphenyl and higher polyphenyls, from which, through distillation at a temperature of 380 to 400 degrees and atmospheric pressure, industrial p-terphenyl is isolated, along with higher polyphenyls, and the distillate from the first stage, which is rectified with bleed off as a distillate of the second stage of the terphenyl mixture.

Chechetkin, A.V.; Kaplan, Ye.P.; Kharaz, D.I.; Nikishin, G.I.

1982-01-01

50

Specific heat capacity and enthalpy of coal pyrolysis at elevated temperatures  

Energy Technology Data Exchange (ETDEWEB)

The success of mathematical models of coal pyrolysis depends on the accuracy of the assumed coal properties. Therefore, an experimental procedure was developed enabling the specific heat capacity and enthalpy of coal pyrolysis in the instantaneous state at a given temperature to be determined. It was used to measure the thermal properties of six coals and the mineral matter at temperatures up to 1300{degree}C. The theoretically predicted maximum of the specific heat capacity at {approximately} 600{degree}C was reproduced experimentally. However, for temperatures {gt} 1000{degree}C the models considerably over predicted the experimental results. It was also found that between 300 and 800{degree}C the decomposition of coal is endothermic, with the enthalpy of reaction {approximately} 120 kJ kg{sup -1} parent coal. Above 800{degree}C decomposition of coal can vary from endothermic to exothermic, with the enthalpy up to 200 kJ kg{sup -1} parent coal. 24 refs., 8 figs., 2 tabs.

Tomeczek, J.; Palyugniok, H. [Silesian Technical University, Katowice (Poland). Dept. of Process Energy

1996-07-01

51

Pyrolysis and ignition of single wooden spheres heated in high-temperature streams of air  

Energy Technology Data Exchange (ETDEWEB)

The ignition of single wooden spheres heated in a hot air stream has been investigated experimentally. Three species of wood were used. The single wooden spheres were oven-dried and exposed to various temperatures and streams of air with different flow rates. The orientation of the grains in the wood was kept either perpendicular or parallel to the air stream. The temperature inside a wooden sphere was monitored by embedded thermocouples. The orientation of grains in the hot air stream had a notable influence on the ignition time, particularly with air at 673 and 773 K. At 873 K neither the flow rate of air nor the orientation of the grain had any effect on the ignition time. Glowing reaction was observed prior to ignition for wooden spheres heated to 773 K, but flaming ignition was found for air at 873 K. A correlation for estimating the ignition times was proposed. A simple one-dimensional model for the pyrolysis of wood, taking account of the heat of pyrolysis and the evaporation of moisture, is capable of predicting the mass loss quite well, but is less satisfactory for predicting the temperature in the period prior to flaming ignition.

Kuo, Jing T.; Hsi, Chih-Lun [Department of Mechanical Engineering, National Taiwan University, Taipei, Taiwan 106 (Republic of China)

2005-09-01

52

Temperature dependence of Fluorine-doped tin oxide films produced by ultrasonic spray pyrolysis  

International Nuclear Information System (INIS)

[en] Fluorine-doped tin oxide (FTO) films were prepared at different substrate temperatures by ultrasonic spray pyrolysis technique on glass substrates. Among F-doped tin oxide films, the lowest resistivitiy was found to be 6.2 x 10-4 ?-cm for a doping percentage of 50 mol% of fluorine in 0.5 M solution, deposited at 400 oC. Hall coefficient analyses and secondary ion mass spectrometry (SIMS) measured the electron carrier concentration that varies from 3.52 x 1020 cm-3 to 6.21 x 1020 cm-3 with increasing fluorine content from 4.6 x 1020 cm-3 to 7.2 x 1020 cm-3 in FTO films deposited on various temperatures. Deposition temperature on FTO films has been optimized for achieving a minimum resistivity and maximum optical transmittance.

2009-12-15

53

[Differences in the mechanisms of low-temperature and high-temperature processes in the formation of 3,4-benzopyrene during wood pyrolysis  

UK PubMed Central (United Kingdom)

In 4 series of experiments a dependence between 3,4-benzpyrene (BP) output and the temperature of fir sawdust pyrolysis under isothermic conditions has been investigated. The experimental series differed in the duration of wood pulp particles stay in the reaction zone (tau). Also EPR spectra of pyrolysis products have been recorded. The experimental series did not differ in an output of ether extract from pyrolysis products, while BP output temperature curves in their shape were found to be largely dependent on tau: with an increased tau these curves definitely showed the maximum in the range of 300-350 degrees C and the BP output raised in the range of this maximum and also at the temperature of 600 degrees C. In the temperature range over 350 degrees C the character of dependence of the EPR signal value on temperature would correlate well with the temperature-dependent BP output, in the range of lower temperatures the EPR signal was not detected. The data obtained are considered as an evidence of two processes of BP formation in wood pyrolysis-a high-temperature process (temperature over 500 degrees C) and low-temperature one (300-350 degrees C). The high-temperature process seems to have the free-radical mechanism of BP formation, whereas in low temperatures it is evidently the result of a ion type reaction.

Dikun PP; Kostenko LD; Liverovski? AA; Shmulevskaia EI; Romanovskaia LS

1975-01-01

54

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

Energy Technology Data Exchange (ETDEWEB)

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

55

Fluidised bed catalytic pyrolysis of scrap tyres: influence of catalyst:tyre ratio and catalyst temperature.  

Science.gov (United States)

Pyrolysis with on-line Zeolite catalysis of scrap tyres was undertaken in a fluidised bed reactor with the aim of maximising the production of higher value single ring aromatic hydrocarbons in the derived oil. Experiments were carried out in relation to the ratio of the catalyst to tyre feedstock and the temperature of the catalyst bed. Two Zeolite catalysts were examined, a Y-type Zeolite catalyst and Zeolite ZSM-5 catalyst of differing pore size and surface activity. The composition of the oils derived from the uncatalysed fluidised bed pyrolysis of tyres showed that benzene concentration was 0.2 wt%, toluene concentration was 0.8 wt%, o-xylene was 0.3 wt%, m/p-xylenes were 1.8 wt% and limonene was 4.3 wt%. Benzene, toluene and xylenes present in the oils showed a significant increase in the presence of both of the catalysts. The maximum concentrations of these chemicals for the Y-Zeolite (CBV-400) catalyst was 1 wt% for benzene, 8wt% for toluene, 3 wt% for o-xylene and 8.5 wt% for m/p-xylenes, produced at a catalyst:tyre ratio of 1.5. There was less influence of catalyst temperature on the yield of benzene, toluene and xylenes, however, increasing the temperature of the catalyst resulted in a marked decrease in limonene concentration. The Y-type Zeolite catalyst produced significantly higher concentrations of benzene, toluene and xylenes which was attributed to the larger pore size and higher surface acidity of the Y-Zeolite catalyst compared to the Zeolite ZSM-5 catalyst. PMID:12549667

Williams, Paul T; Brindle, Alexander J

2002-12-01

56

Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 11, March 15, 1990--June 15, 1990  

Energy Technology Data Exchange (ETDEWEB)

We made considerable progress towards completing the development of a thermogravimetric reactor with video microscopy imaging capabilities (TGA/VMI). The video micrOSCOPY components were designed, installed and are currently under testing. With the newly developed TGA/VNH apparatus we can directly observe macroscopic changes in the morphology of pyrolyzing particles and thermal ignitions of burning particles while simultaneously monitoring the weight of pyrolyzing or reacting samples. The systematic investigation on the effects of pyrolysis conditions and char macropore structure on char reactivity continued. Pyrolysis and gasification experiments were performed consecutively in our TGA reactor and the char reactivity patterns were measured for a wide range of temperatures (400--600{degrees}C). These conditions cover both the kinetic and the diffusion limited regimes. Our results show conclusively that chars produced at high pyrolysis heating rates (and, therefore, having a more open cellular macropore structure) are more reactive and ignite more easily than chars pyrolyzed at low heating rates. These results have been explained using theoretical models. We also investigated for the first time the effect of coal particle size and external mass transfer limitations on the reactivity patterns and ignition behavior of char particles combusted in air. Finally, we used our hot stage reactor to monitor the structural transformations occurring during pyrolysis via a video microscopy system. Pyrolysis experiments were videotaped and particle swelling and the particle ignitions were determined and analyzed using digitized images from these experiments.

Zygourakis, K.

1990-12-31

57

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)

2007-01-01

58

Influence of temperature and rate of humidity on flash-pyrolysis of lignocellulosic wastes  

Energy Technology Data Exchange (ETDEWEB)

The authors present the experimental study of conversion between 500 and 1000/sup 0/C of lignocellulosic wastes into gaseous fuel through sudden pyrolysis in the absence of air or oxygen of dried Douglas or beechwood sawdust or sawdust impregnated with water up to 100%. They describe the experimental assembly, the measurements made and the interpretation thereof: relationship between mass of gaseous products and the initial mass of the sampling G.V.H. of gases, type and content of gases and residues according to temperature and rate of humidity, speed and time of reaction according to grain size. Based on these results, the authors establish the stochiometric equations of gasification and determine the reaction heats: those supplying a gas of nearly 19000 kJ/cubic m, of G.V.H. is exo- or athermic to about 700/sup 0/C and then slightly endothermic beyond this point (1500 kJ/kg).

Deglis, X.; Richard, C.; Rolin, A.; Francois, H.

1980-11-01

59

Pyrolysis studies of organic oxygenates 3. High temperature rearrangement of aryl alkyl ethers  

Energy Technology Data Exchange (ETDEWEB)

Thermal chemistry pathways of aryl alkyl ethers have been investigated under coal conversion-like conditions. Anisole is a thermally reactive compound having an oxygen functionality found in such coal precursors as lignins. Pyrolysis of anisoles was carried out using small batch autoclaves. Under thermolysis conditions anisole yielded a product distribution strongly dependent upon experimental parameters. Phenol, methane, CO and benzaldehyde are the low molecular weight products and polyphenyls and polyethers are the predominant high molecular weight products. The generation of CO is explained by a high temperature rearrangement of the phenyl group from O- to C- followed by rapid thermal decarbonylation of the benzaldehyde. Carbon monoxide formation from aryl alkyl ether can thus be an important mechanistic pathway in coal conversion processes. By investigating the rearrangement using para-fluoroanisole it was shown that this rearrangement proceeds via a threecentered intermediate to para-fluorobenzaldehyde. No meta isomer was observed.

Schlosberg, R.H.; Ashe, T.R.; Danik, J.A.; Dupre, G.D.; Kurs, A.; Olmstead, W.N.; Szajowski, P.F.

1983-06-01

60

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

Science.gov (United States)

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

 
 
 
 
61

Low temperature synthesis of wurtzite zinc sulfide (ZnS) thin films by chemical spray pyrolysis.  

UK PubMed Central (United Kingdom)

Zinc sulfide (ZnS) thin films have been synthesized by spray pyrolysis at 310 °C using an aqueous solution of zinc chloride (ZnCl2) and thioacetamide (TAA). Highly crystalline films were obtained by applying TAA instead of thiourea (TU) as the sulfur source. X-ray diffraction (XRD) analyses show that the films prepared by TAA contained a wurtzite structure, which is usually a high temperature phase of ZnS. The crystallinity and morphology of the ZnS films appeared to have a strong dependence on the spray rate as well. The asymmetric polar structure of the TAA molecule is proposed to be the intrinsic reason of the formation of highly crystalline ZnS at comparatively low temperatures. The violet and green emissions from photoluminescence (PL) spectroscopy reflected the sulfur and zinc vacancies in the film. Accordingly, the photodetectors fabricated using these films exhibit excellent response to green and red photons of 525 nm and 650 nm respectively, though the band gaps of the materials, estimated from optical absorption spectroscopy, are in the range of 3.5-3.6 eV.

Zeng X; Pramana SS; Batabyal SK; Mhaisalkar SG; Chen X; Jinesh KB

2013-05-01

62

Studies on liquefaction and pyrolysis of peat and biomass at KTH  

International Nuclear Information System (INIS)

A brief review of the study on thermochemical conversion of solid fuels is done. The study have been performed in the Royal Institute of Technology, Stockholm, since the outbreak of energy crisis in the seventies. The main problems connected with utilisation of peat for energy are: 90% moisture content in the deposits and 35-40% oxygen content in the dry substance. Simultaneous dewatering and liquefaction of peat have been achieved by the Bjoerbom method. The wet peat has been treated with CO and H2O without preliminary drying, using water as a medium agent. After treatment water has been phase-separated from the heavy oil product. Another approach is de-oxygenation of peat prior to liquefaction. A significant part of oxygen in peat and biomass can be removed by thermal decomposition of the fuels prior to liquefaction and removal of carbon dioxide and water from the organic matter in them. The products obtained after de-oxygenation demand low consumption of external hydrogenation agent because they are rich in hydrogen. Some criteria for selection of peat as a raw material for liquefaction are given. The equipment and experimental procedure for pyrolysis of peat and biomass are described. A free fall tubular reactor with max operating pressure of 5 MPa and temperature of 1100oC has been used. The effect of treatment conditions under the rapid pyrolysis in the free fall reactor on the yield and the reactivity of char obtained after the final pyrolysis is shown. Peat and wood are transformed into pyrolysis products for less than 1 second; 35-50% of the moisture- and ash-free peat and 70% of the wood have been converted into gaseous products.The char obtained in the rapid pyrolysis contains a fraction which can be further de-volatilized by slow pyrolysis for a few minutes - time much longer than the time for formation of primary products. High reactivity of char is favoured by lower pyrolysis temperature, shorter residence time and larger particle size of the fuel. 3 tabs., 22 refs

1996-01-01

63

Pyrolysis-chromatographic analysis of brown coal  

Energy Technology Data Exchange (ETDEWEB)

The paper identifies chemical compounds in pyrolysis products, gained by thermal treatment of brown coal samples. Soft brown coal, hard brown coal and xylite were investigated; maximum pyrolysis temperature was 730 C. Chromatographic peaks of volatile substances are explained; identified compounds and their Kovats index between 930 and 2,368 are listed. Various graphs demonstrate the percentage of major substances in the pyrolysis product, the effect of degree of coalification on pyrolysis products, relation of oxygen-carbon content and the change in composition of pyrolysis products by varying pyrolysis temperature or by rapid increase in pyrolysis temperature. (9 refs.)

Kohl, M.; Macak, J.; Kubat, J.

1980-01-01

64

Shock tube investigation of major pathways in the high-temperature pyrolysis of benzene  

Energy Technology Data Exchange (ETDEWEB)

The high-temperature pyrolysis of benzene, 1 and 2 mol % in krypton, has been studied in the shock tube with the laser-schlieren technique over 1900-2400 K and 0.2-1.0 atm. A completely successful modeling of the density gradient profiles and some time-of-flight mass spectra is achieved with a simple radical chain mechanism consisting of essentially just four reactions. The dissociation is solely CH bond scission (M) + C/sub 6/H/sub 6/ ..-->.. C/sub 6/H/sub 5/ + H + (M) whose rates are strongly dependent on both temperature and pressure in this range; this reaction is near second order for T > 2300 K. An RRKM fit to these data suggests a barrier of 112 +/- 2 kcal/mol, which corresponds to ..delta..H/sub f//sup 0//sub 298/ = 80 +/- 2 kcal/mol for the phenyl radical heat of formation, and an average collisional energy transfer of (-..delta..E)/sub all/ = 70 cm/sup -1/. The extrapolated K/sub infinity/ for this reaction is 2 x 10/sup 17/ exp(-118000 (cal)/RT) s/sup -1/ (1900-2400 K). The model also indicates a rate constant of 2.5 x 10/sup 14/ exp(-16000 (cal)/RT cm/sup 3//(mol s) (1900-2200 K) for the abstraction H + C/sub 6/H/sub 6/ ..-->.. C/sub 6/H/sub 5/ + H/sub 2/. 31 references, 9 figures, 3 tables.

Kiefer, J.H.; Mizerka, L.J.; Patel, M.R.; Wei, H.C.

1985-05-09

65

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

66

Low-temperature pyrolysis of brown coal and brown coal containing iron hydroxyl complexes  

Energy Technology Data Exchange (ETDEWEB)

The concentrations profiles of CO{sub 2} and CO have been measured at 150-600{sup o}C from the pyrolysis, at slow heating rates, of acid-washed brown coal and brown coal containing iron hydroxyl complexes. CO{sub 2} formation was greater at low temperatures, but CO increased relative to CO{sub 2} with an increasing temperature. The ratio CO{sub 2}/CO was larger for coal with iron, compared to that from acid-washed coal. The iron species in the chars were Fe{sub 2}O{sub 3} at 200-400{sup o}C, Fe{sub 2}O{sub 3} and Fe{sub 3}O{sub 4} at 400-600{sup o}C, and Fe{sup 0} at 700{sup o}C; inorganic carbonate was also detected. Although conventional chemical kinetic simulations could reproduce the total weight loss of coal with temperature, such calculations could not simulate the measured CO{sub 2} and CO concentration profiles. Decarboxylation reactions may proceed via a number of reaction routes, including ones involving intermediate species. Semiempirical quantum mechanics modeling (SE-QM) of decarboxylation using three carboxylic compounds provided a relative order of decomposition as carboxylic acid {approximately} carboxylate {much_gt} radical. SE-QM and single-point self-consistent field (1scf) calculations, using 2D and 3D models of brown coal, were conducted to provide changes in the heats of formation for models after the loss of carboxyl groups. Such calculations also indicated that hydrogen transfer from a phenoxyl group to a carbanion was energetically favored. The formation of the various iron oxides in coal was modeled by (I) decarboxylation reactions via an iron-carbonato complex decomposing into CO{sub 2} and a {mu}-oxo iron complex and (ii) decarboxylation of coal via the reduction of iron complexes and the formation of organic radicals. 53 refs., 6 figs., 3 tabs.

George Domazetis; Monthida Raoarun; Bruce D. James [La Trobe University, Vic. (Australia). Chemistry Department

2006-10-15

67

Catalytic deoxygenation of liquid biomass for hydrocarbon fuels  

Energy Technology Data Exchange (ETDEWEB)

Liquid biomass such as methyl laurate and canola oil is deoxygenated with hydrogen and NiMo/{gamma}-Al{sub 2}O{sub 3} catalyst. Oxygen from methyl laurate and canola oil is removed at 18.25-85.13 bar initial cold hydrogen pressure and 300-400 C, using a 316 stainless steel batch reactor. Removal of oxygen from liquid methyl laurate and canola oil is evaluated with a GC/MS analyzer for liquid reaction products and another GC for gaseous reaction products. The range of reaction duration of liquid biomass in the batch reactor is 30-60 min under the deoxygenation conditions. Conversion of liquid biomass into gaseous products is evaluated with analysis data of gas products and a mass balance in terms of hydrogen. The objective of this research is to develop an efficient method of removing oxygen from liquid biomass to produce petroleum-comparative liquid hydrocarbons with hydrogen and a catalyst. Removal of oxygen from bio-based fuels for liquid hydrocarbon fuel is needed to increase its energy intensity, stability, and decrease its viscosity. In this paper, removal of oxygen from methyl laurate and canola oil is discussed in detail in terms of various oxygen removal conditions such as reaction temperature and pressure, catalyst amount, and hydrodynamics of heterogeneous reaction mixture in the batch reactor. (author)

Kwon, Kyung C. [Chemical Engineering Department, Tuskegee University, Tuskegee, AL 36088 (United States); Mayfield, Howard [AFRL, Tyndall Air Force, Panama City, Florida (United States); Marolla, Ted [AFRL, Tyndall Air Force, Panama City, Florida (United States); Applied Research Associates, Inc, Panama City, Florida (United States); Nichols, Bob [Applied Research Associates, Inc, Panama City, Florida (United States); Mashburn, Mike [Physics Department, Florida State University, Tallahassee, Florida (United States)

2011-03-15

68

Study of a new macro-particle model for the low-temperature pyrolysis of dried wood chips  

Science.gov (United States)

This paper presents a transient one-dimensional mathematical model which simulates the pyrolysis of a single dried wood particle. The porous wood particle is considered as a two-phase system: the solid phase consisting of wood and char and the gas phase consisting of volatiles and tar. Conservation equations for mass, momentum and energy are developed for each phase. Chemical processes are described through an existing one-stage three-reactions scheme, leading separately to char, tar and volatiles evolution dynamics. The variation of transport and physical properties with temperature and with composition is presented by algebraic equations. The model presented in this paper is more advanced than the current models found in literature, since it contains physical effects not included in past models, such as cross diffusion, differing solid and gas phase temperatures and a transient gas phase momentum equation incorporating the wall friction experienced by a fluid flowing through a porous medium. Furthermore, an adequate reference system for enthalpy, based on temperature dependent reaction heats, is used. The mathematical equations with initial and boundary conditions are solved numerically by means of a commercial CFD code (PHOENICS). The validity of the pyrolysis kinetics scheme is examined through comparison with experimental data. Furthermore, the macro-particle model is validated by (1) examining the limitations and importance of the newly-modelled effects (different solid phase and gas phase temperature, cross diffusion and wall friction) and (2) making a comparison between predicted and experimental results for large particles.

Helsen, L. M. L.; Van den Bulck, E. V. M.

69

Rapid pyrolysis of lignite coal  

Energy Technology Data Exchange (ETDEWEB)

The paper presents rapid pyrolysis results of Bulgarian brown coal, obtained on a continuously working laboratory reactor with a coal throughput of 3 kg/h. Pyrolysis product yields and composition are compared to those from slow pyrolysis. Differences in thermal decomposition processes with rapid and slow pyrolysis are outlined. Maximum tar yield during rapid pyrolysis (0.5 to 1.5 s residence time of vapor and gaseous pyrolysis products in the reactor) was gained in the temperature range of 580 to 600 C. This yield varies between 15 and 18%, which is 110 to 130% of the yield gained by the Fischer process. Liquid products contain up to 40% phenols, which is twice the amount produced by slow pyrolysis. Heating rate between 1 and 20 K/min did not influence yield and composition of liquid products gained from rapid pyrolysis at temperatures below 520 C, thus showing that temperatures above 500 C are required to intensify thermal decomposition. Rapid pyrolysis gas (calorific value of 18 MJ/m/sup 3/) has a lower hydrogen and carbon dioxide content and a higher carbon monoxide and unsaturated hydrocarbon content than slow pyrolysis gas. Maritsa East brown coal has a high (4-5%) sulfur content: liquid pyrolysis products show a sulfur content of 1.5%; the produced semicoke (calorific value of 16 MJ/kg) has 70% of the initial brown coal sulfur content. (18 refs.)

Dimitrova, Z.; Ristzev, D.; Vulkov, V.

1982-01-01

70

Sustainable valorization of plastic wastes for energy with environmental safety via High-Temperature Pyrolysis (HTP) and High-Temperature Steam Gasification (HTSG)  

International Nuclear Information System (INIS)

In the present study the energetic valorization of electric cable shredder residues (mixed plastics) has been investigated. Thermochemical conversion by means of High-Temperature Steam Gasification (HTSG) and High-Temperature Pyrolysis (HTP) was studied. The effects of temperature and reaction time - process parameters - were investigated. Comparison of the results showed that HTSG seems a more suitable process in terms of produced syngas quality (64%, v/v and 13 MJ/Nm3) than HTP because of higher H2 yield and lower tar content.

2009-08-15

71

The fluidized bed pyrolysis of shredded tyres: the influence of carbon particles, humidity, and temperature on the hydrodynamics  

Energy Technology Data Exchange (ETDEWEB)

Ultrafine carbon particles (d{sub sv}=165 nm) are formed from the pyrolysis of shredded tyres in a fluidized bed reactor. The carbon particles affect the hydrodynamic properties of the fluidized bed itself, such as the minimum fluidization velocity U{sub mf}, the elutriation rate, etc. This work investigates how humidity and temperature influence the elutriation rate constant K{sub i}* of the carbon particles, and how the presence of ultrafine carbon particles in a sand bed influence the minimum fluidization velocity. (orig.)

Wu Shuyii; Su Maofeng [Feng Chia Univ., Taichung (Taiwan, Province of China). Dept. of Chemical Engineering; Baeyens, J. [Katholieke Univ. Leuven, Heverlee (Belgium). Dept. of Chemical Engineering

1997-10-15

72

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)

1995-01-01

73

Bio-oil and bio-char from low temperature pyrolysis of spent grains using activated alumina.  

UK PubMed Central (United Kingdom)

The pyrolysis of wheat and barley spent grains resulting from bio-ethanol and beer production respectively was investigated at temperatures between 460 and 540 °C using an activated alumina bed. The results showed that the bio-oil yield and quality depend principally on the applied temperature where pyrolysis at 460 °C leaves a bio-oil with lower nitrogen content in comparison with the original spent grains and low oxygen content. The viscosity profile of the spent grains indicated that activated alumina could promote liquefaction and prevent charring of the structure between 400 and 460 °C. The biochar contains about 10-12% of original carbon and 13-20% of starting nitrogen resulting very attractive as a soil amendment and for carbon sequestration. Overall, value can be added to the spent grains opening a new market in bio-fuel production without the needs of external energy. The bio-oil from spent grains could meet about 9% of the renewable obligation in the UK.

Sanna A; Li S; Linforth R; Smart KA; Andrésen JM

2011-11-01

74

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.

2006-01-01

75

Methyl oleate deoxygenation for production of diesel fuel aliphatic hydrocarbons over Pd/SBA-15 catalysts.  

UK PubMed Central (United Kingdom)

BACKGROUND: Catalytic deoxygenation is a prominent process for production of renewable fuels from vegetable oil. In this work, deoxygenation of technical grade methyl oleate to diesel fuel aliphatic hydrocarbons (C15 -- C18) is evaluated with several parameters including temperature, hydrogen pressure and reaction time in a stirred batch reactor over Pd/SBA-15 catalysts. RESULTS: Two different SBA-15 morphologies i.e. spherelike and necklacelike structures have been synthesize as supports for Pd active metal. It is found that Pd dispersion on necklacelike SBA-15 is higher than that of spherelike SBA-15. Notably, higher Pd dispersion on necklacelike SBA-15 provides significant deoxygenation efficiency as compared to Pd/SBA-15-spherelike. Results show that H2 pressures greatly determine the total ester conversion and selectivity to C15 -- C18 aliphatic hydrocarbons. Total ester conversions with 55% selectivity to n-heptadecane are achieved using Pd/SBA-15-necklacelike at 270[degree sign]C and 60 bar H2 pressure within 6 h reaction time. Gas phase study reveals that formation of C17 is generated via indirect decarbonylation when the reaction time is prolonged. CONCLUSIONS: Pd/SBA-15-necklacelike catalyst exhibits good catalytic performance with high selectivity to diesellike aliphatic hydrocarbons (C15 -- C18). The physicochemical properties of the Pd supported on different SBA-15 morphologies influence the deoxygenation activity of the catalysts. Furthermore, the reaction pathways are governed by the H2 pressure as well as reaction duration.

Lee SP; Ramli A

2013-09-01

76

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

International Nuclear Information System (INIS)

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 °C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration decreased significantly for films pyrolyzed at 900 °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 °C for 40 min was found to be the most efficacious in removing adventitious carbon and oxygen impurities from the surface.

2012-01-01

77

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

78

Effect of deoxygenation on the weak link behavior of YBCO superconductors  

CERN Multimedia

A systematic study of the weak- link behavior for YBa2Cu3O7-d polycrystalline samples has been done using the electrical resistivity and AC susceptibility techniques.The experiments were performed with two samples of similar grain, a sample of well-coupled grains, and a deoxygenated sample in such a way that the oxygen mostly come from the intergrain region. Analysis of the temperature dependence of the AC susceptibility near the transition temperature (Tc) has been done employing Bean critical state model. The observed variation of intergranular critical current densities(Jc)with temperature indicates that the weak links are changed from superconductor- normal metal-superconductor(SNS) for well-coupled sample to superconductor-insulator- normal metal-superconductor(SINS) type of junctions for the deoxygenated sample.These results are interpreted in terms of oxygen depletion from grain boundaries, which in turn decreases the intergranular Josephson coupling energy with a consequent decrease ofpinning of the i...

Salamati, H

2002-01-01

79

Arsenic speciation in solid biological specimens by temperature-controlled pyrolysis and NAA  

International Nuclear Information System (INIS)

A pyrolysis-neutron activation analysis (NAA) procedure has been developed and applied to the speciation of arsenic in solid biological samples. The method involves the retention of the inorganic arsenic in the pyrolysis boat by the addition of NaOH, the votatilization and trapping of the organic arsenic on a cation exchange resin and the subsequent NAA of the resin for the determination of the trapped arsenic. The method, developed with the aid of radiochemically labelled arsenic compounds, has been applied to the determination of the ratio of inorganic to organic arsenic species in commerical shrimps as well as in NBS standard reference materials such as oysters and orchard leaves. The results show different relative amounts of inorganic arsenic content in the samples analysed. In the shrimps the fraction of inorganic arsenic was of the order of 20%, in the oysters the inorganic arsenic constituted 60% of the total arsenic concentration while in the samples of vegetable origin more than 98% of the arsenic was of inorganic nature. (author)

1986-01-01

80

Bio-oil upgrading via catalytic pyrolysis of waste mandarin residue over SBA-15 catalysts.  

UK PubMed Central (United Kingdom)

Mesoporous SBA-15-based catalysts were applied, for the first time, to the pyrolysis of waste mandarin residue. Si-SBA-15 with few acid sites, Al-SBA-15 with a significant amount of acid sites owing to the alumination treatment, and Pt/Al-SBA-15, which was synthesized by incorporating 7.1-nm Pt nanoparticles on Al-SBA-15, were used. Pyrolysis experiments were conducted by pyrolysis gas chromatography/mass spectroscopy to determine the catalytic activities of the catalysts used. X-ray diffraction, nitrogen adsorption, NH3-temperature-programmed desorption and transmission electron microscopy were used to characterize the catalysts. Al-SBA-15 produced higher quality bio-oil than Si-SBA-15 due to its better deoxygenation and cracking performance stemming from the presence of acid sites. Pt/Al-SBA-15 showed the highest oxygenate conversion as well as the largest yield of high-value-added compounds, such as aromatics, low-molecular-mass hydrocarbons and furans.

Kim JW; Joo SH; Seo B; Kim SS; Shin DH; Park SH; Jeon JK; Park YK

2013-04-01

 
 
 
 
81

Desulphurization of a Turkish lignite by pyrolysis: comparison of slow and flash pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

To observe the effect of the heating rate on the desulphurization, Bolu-Mengen lignite was desulphurized in the temperature range of 450-750[degree]C using flash and slow pyrolysis methods. A reduction of 57.6% and 34.2% in the total sulphur was obtained for the slow and flash pyrolysis at a pyrolysis temperature of 750[degree]C, respectively. It was observed that the flash pyrolysis is shifted toward higher temperatures with respect to the slow pyrolysis. The flash pyrolysis having high thermal efficiency has a potential as a desulphurization process. 27 refs., 5 figs., 2 tabs.

Ersahan, H. (Ataturk University, Erzurum (Turkey). Dept. of Chemical Engineering)

1994-01-01

82

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

83

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 280°C. 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 220°C found to be amorphous and polycrystalline at 250 and 280°C 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 250°C. The effect of substrate temperature on crystalline structure, surface morphology and composition were analyzed and reported.

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

2012-01-01

84

Low-temperature pyrolysis of CCA-treated wood waste: Chemical determination and statistical analysis of metal input and output; mass balances  

Energy Technology Data Exchange (ETDEWEB)

Low-temperature pyrolysis is proposed as an alternative method to dispose of CCA-treated wood waste. In the frame of a study aiming at optimizing the pyrolysis of CCA-treated wood, an experimental facility has been built to examine the influence of important process parameters (pyrolysis temperature, residence time, heating rate, particle size, {hor_ellipsis}) on the release of metals and on the resultant mass reduction. In order to perform a mass balance calculation for the total system, a method for metal analysis was developed. Two leaching procedures and one dissolution procedure were tested and compared with each other, resulting in an optimal procedure to bring the metals into solution: the BSI method to determine the total amount of Cr, Cu and As in the dried wood and the Reflux method to determine the total amount of Cr, Cu and As in the pyrolysis residue. These results illustrate that Cr is more strongly bound in the pyrolysis residue compared to the CCA-treated wood. The analytical technique used was ICP-MS and the analytical problems like interferences and matrix effects were solved by using the appropriate isotope, an internal standard and mathematical corrections. The resulting optimal technique for CCA-treated wood (the BSI method) was applied to wood samples with different particle sizes. A statistical analysis of the Cr, Cu and As content in the CCA-treated wood shows the heterogeneous character of CCA-treated wood samples. Heterogeneity becomes less important when using samples with a small range of particle sizes. The smaller wood particles have significantly higher metal concentrations than the larger particles. Realistic mass balances for the metals were obtained and showed that most of the Cr, Cu and As remained in the pyrolysis residue.

Helsen, L.; Bulck, E. van den; Broeck, K. van den; Vandecasteele, C. [Katholieke Univ. Leuven, Heverlee (Belgium)

1997-12-31

85

Impact of pyrolysis temperature and manure source on physicochemical characteristics of biochar.  

UK PubMed Central (United Kingdom)

While pyrolysis of livestock manures generates nutrient-rich biochars with potential agronomic uses, studies are needed to clarify biochar properties across manure varieties under similar controlled conditions. This paper reports selected physicochemical results for five manure-based biochars pyrolyzed at 350 and 700°C: swine separated-solids; paved-feedlot manure; dairy manure; poultry litter; and turkey litter. Elemental and FTIR analyses of these alkaline biochars demonstrated variations and similarities in physicochemical characteristics. The FTIR spectra were similar for (1) turkey and poultry and (2) feedlot and dairy, but were distinct for swine biochars. Dairy biochars contained the greatest volatile matter, C, and energy content and lowest ash, N, and S contents. Swine biochars had the greatest P, N, and S contents alongside the lowest pH and EC values. Poultry litter biochars exhibited the greatest EC values. With the greatest ash contents, turkey litter biochars had the greatest biochar mass recoveries, whereas feedlot biochars demonstrated the lowest.

Cantrell KB; Hunt PG; Uchimiya M; Novak JM; Ro KS

2012-03-01

86

Structural evolution and optical characterization of indium doped cadmium sulfide thin films obtained by spray pyrolysis for different substrate temperatures  

Energy Technology Data Exchange (ETDEWEB)

Indium doped cadmium sulfide thin films were prepared by spray pyrolysis on glass substrates at different temperatures ranging from 300 deg C to 450 deg C in 25 deg C steps, using aqueous solution of copper chloride and thiourea salts. We used In(COOH){sub 3} as the dopant. Structural characterization was carried out by X-ray diffractometry and scanning electron microscopy and high resolution electron microscopy were used together with atomic force microscopy (AFM) to follow the evolution of structural and morphological parameters of the films with substrate temperature (T{sub s}), At least two preferential growth, (1 1 2) for samples with T{sub s} between 325 deg C and 400 deg C and (0 0 2) for T{sub s} between 400 deg C and 450 deg C, respectively were detected. For the films obtained at higher substrate temperatures, HREM micrographs revealed the presence of a large number of structural defects together with nanostructured configurations. AFM revealed surface modifications of CdS:In grains at higher substrate temperature. The substrate temperature is directly related with the shift detected in the band gap values derived from optical of parameters. (Author)

Acosta, Dwight R.; Magana, Carlos R.; Martinez, Arturo I. [UNAM, Instituto de Fisica, Mexico City (Mexico); Maldonado, Arturo [CINVESTAV, Dept. de Ingenieria Electrica, Mexico City (Mexico)

2004-05-01

87

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

International Nuclear Information System (INIS)

[en] 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)

2013-01-01

88

DEOXYGENATION OF FATTY ACIDS FOR PREPARATION OF HYDROCARBONS  

UK PubMed Central (United Kingdom)

Embodiments of methods for making renewable diesel by deoxygenating fatty acids to produce hydrocarbons are disclosed. Fatty acids are exposed to a catalyst selected from a) M1 /M2 /M3O2 where M1 is a transition metal, a transition metal oxide, or a combination thereof, wherein the transition metal is Fe, Mn, Mo, V, or W, M2 is Pt, PtO, PtO2, or a combination thereof, and M3 is Ti or Zr, or b) Pt/Ge or Pt/Sn on carbon, and the catalyst decarboxylates at least 10% of the fatty acids. Deoxygenation is performed without added hydrogen and at less than 100 psi. Disclosed embodiments of the catalysts deoxygenate at least 10% of fatty acids in a fatty acid feed, and remain capable of deoxygenating fatty acids for at least 200 minutes to more than 350 hours.

HALLEN RICHARD T; ALBRECHT KARL O; BROWN HEATHER M; WHITE JAMES F

89

From biomass to advanced bio-fuel by catalytic pyrolysis/hydro-processing: hydrodeoxygenation of bio-oil derived from biomass catalytic pyrolysis.  

UK PubMed Central (United Kingdom)

Compared hydrodeoxygenation experimental studies of both model compounds and real bio-oil derived from biomass fast pyrolysis and catalytic pyrolysis was carried out over two different supported Pt catalysts. For the model compounds, the deoxygenation degree of dibenzofuran was higher than that of cresol and guaiacol over both Pt/Al(2)O(3) and the newly developed Pt supported on mesoporous zeolite (Pt/MZ-5) catalyst, and the deoxygenation degree of cresol over Pt/MZ-5 was higher than that over Pt/Al(2)O(3). The results indicated that hydrodeoxygenation become much easier upon oxygen reduction. Similar to model compounds study, the hydrodeoxygenation of the real bio-oil derived from catalytic pyrolysis was much easier than that from fast pyrolysis over both Pt catalysts, and the Pt/MZ-5 again shows much higher deoxygenation ability than Pt/Al(2)O(3). Clearly synergy between catalytic pyrolysis and bio-oil hydro-processing was found in this paper and this finding will lead an advanced biofuel production pathway in the future.

Wang Y; He T; Liu K; Wu J; Fang Y

2012-03-01

90

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

91

Low-temperature growth of highly crystallized transparent conductive fluorine-doped tin oxide films by intermittent spray pyrolysis deposition  

Energy Technology Data Exchange (ETDEWEB)

Following the procedure by Sawada et al. (Thin Solid Films 409 (2002) 46), high-quality SnO{sub 2}:F films were grown on glass substrates at relatively low temperatures of 325-340C by intermittent spray pyrolysis deposition using a perfume atomizer for cosmetics use. Even though the substrate temperature is low, as-deposited films show a high optical transmittance of 92% in the visible range, a low electric resistivity of 5.8x10{sup -4}{omega}cm and a high Hall mobility of 28cm{sup 2}/Vs. The F/Sn atomic ratio (0.0074) in the films is low in comparison with the value (0.5) in the sprayed solution. The carrier density in the film is approximately equal to the F-ion density, suggesting that most of the F-ions effectively function as active dopants. Films' transmittance and resistivity show little change after a 450C 60min heat treatment in the atmosphere, evidencing a high heat resistance. The SnO{sub 2}:F films obtained in this work remove the difficulty to improve the figure of merit at low synthesis temperatures.

Fukano, Tatsuo; Motohiro, Tomoyoshi [Toyota Central Research and Development Laboratories Inc., Nagakute, Aichi 480-1192 (Japan)

2004-05-30

92

A shock tube, laser-schlieren study of propene pyrolysis at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

Laser-schlieren, shock tube methods have been used to determine the rate of initiation in propene pyrolysis. Given that the dominant initiation reaction is M + C/sub 3/H/sub 6/ ..-->.. CH/sub 3/ + C/sub 2/H/sub 3/ + M, the rate constant over 1650-2300 K and 1 x 10/sup -6/ < (M) < 2.2 x 10/sup -6/ mol/cm/sup 3/ is 5.4 x 10/sup 75/T/sup -//sup 15.7/ exp(-120000/(RT)) cm/sup 3//(mol s)(R in cal/(mol K)). There is no clear difference between C/sub 3/H/sub 6/ and Kr as M. This rate was obtained by a computer simulation assisted extrapolation to the presumed instant of shock heating ( t = O) and the derivation of an initial rate by using calculated frozen reaction conditions. This rate is in reasonable agreement with previous single-pulse shock tube measurements, and suggests that the reaction is in the falloff region in all the shock-tube studies. A possible contribution by C/sub 3/H/sub 6/ ..-->.. C/sub 3/H/sub 5/ + H cannot be excluded.

Kiefer, J.H.; Al-Alami, M.Z.; Budach, K.A.

1982-01-01

93

Production of bio-fuels by high temperature pyrolysis of sewage sludge using conventional and microwave heating.  

UK PubMed Central (United Kingdom)

The pyrolysis of sewage sludge was investigated using microwave and electrical ovens as the sources of heat, and graphite and char as microwave absorbers. The main objective of this work was to maximize the gas yield and to assess its quality as a fuel and as a source of hydrogen or syngas (H2 + CO). Both gases were produced in a higher proportion by microwave pyrolysis than by conventional pyrolysis, with a maximum value of 38% for H2 and 66% for H2 + CO. The oils obtained were also characterized using FTIR and GC-MS. The use of conventional electrical heating in the pyrolysis of sewage sludge produced an oil that could have a significant environmental and toxicological impact. Conversely, microwave pyrolysis still preserved some of the functional groups of the initial sludge such as aliphatic and oxygenated compounds, whereas no heavy PACs were detected.

Domínguez A; Menéndez JA; Inguanzo M; Pís JJ

2006-07-01

94

Production of bio-fuels by high temperature pyrolysis of sewage sludge using conventional and microwave heating.  

Science.gov (United States)

The pyrolysis of sewage sludge was investigated using microwave and electrical ovens as the sources of heat, and graphite and char as microwave absorbers. The main objective of this work was to maximize the gas yield and to assess its quality as a fuel and as a source of hydrogen or syngas (H2 + CO). Both gases were produced in a higher proportion by microwave pyrolysis than by conventional pyrolysis, with a maximum value of 38% for H2 and 66% for H2 + CO. The oils obtained were also characterized using FTIR and GC-MS. The use of conventional electrical heating in the pyrolysis of sewage sludge produced an oil that could have a significant environmental and toxicological impact. Conversely, microwave pyrolysis still preserved some of the functional groups of the initial sludge such as aliphatic and oxygenated compounds, whereas no heavy PACs were detected. PMID:16473008

Domínguez, A; Menéndez, J A; Inguanzo, M; Pís, J J

2006-02-10

95

De-oxygenation of CO2 by using Hydrogen, Carbon and Methane over Alumina-Supported Catalysts  

Directory of Open Access Journals (Sweden)

Full Text Available The de-oxygenation of CO2 was explored by using hydrogen, methane, carbon etc., over alumina supported catalysts. The alumina-supported ruthenium, rhodium, platinum, molybdenum, vanadium and magnesium catalysts were first reduced in hydrogen atmosphere and then used for the de-oxygenation of CO2. Furthermore, experimental variables for the de-oxygenation of CO2 were temperature (range 50 to 650 oC), H2/CO2 mole ratios (1.0 to 5), and catalyst loading (0.5 to 10 wt %). During the de-oxygenation of CO2 with H2 or CH4 or carbon, conversion of CO2, selectivity to CO and CH4 were estimated. Moreover, 25.4 % conversion of CO2 by hydrogen was observed over 1 wt% Pt/Al2O3 catalyst at 650 oC with 33.8 % selectivity to CH4. However, 8.1 to 13.9 % conversion of CO2 was observed over 1 wt% Pt/Al2O3 catalyst at 550 oC in the presence of both H2 and CH4. Moreover, 42.8 to 79.4 % CH4 was converted with 9 to 23.1 % selectivity to CO. It was observed that the de-oxygenation of CO2 by hydrogen, carbon and methane produced carbon, CO and CH4. © 2012 BCREC UNDIP. All rights reservedReceived: 6th February 2012; Revised: 23rd April 2012; Accepted: 24th April 2012[How to Cite: R. Y. Raskar, K. B. Kale, A. G. Gaikwad. (2011). De-oxygenation of CO2 by using Hydrogen, Carbon and Methane over Alumina-Supported Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 7 (1): 59-69. doi:10.9767/bcrec.7.1.1631.59-69][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.1.1631.59-69 ] | View in

R.Y. Raskar; K.B. Kale; A.G. Gaikwad

2012-01-01

96

Use of low-temperature nanostructured CuO thin films deposited by spray-pyrolysis in lithium cells  

Energy Technology Data Exchange (ETDEWEB)

Nanostructured CuO thin films were prepared by spray pyrolysis of aqueous copper acetate solutions at temperatures over 200-300 deg C range. The textural and structural properties of the films were determined by scanning electron microscopy, atomic force microscopy, X-ray diffraction spectroscopy and X-ray photoelectron spectroscopy (XPS). Although the sole crystalline phase detected in the film was CuO, XPS spectra revealed a more complex surface structure due to the presence of undecomposed copper acetate that can be easily removed by Ar{sup +} ion sputtering. The heating temperature was found to have little limited effect on the particle size and thickness of the films, which, however, increased significantly increasing deposition time. The film with the smallest grain size exhibited an excellent electrochemical response in Li battery electrodes and was capable of supplying sustained specific capacity as high as 625 A h kg{sup -1} (50% greater than that delivered by bulk CuO and close to the theoretical capacity for the CuO<=>Cu reaction) upon extensive cycling.

Morales, J. [Departamento de Quimica Inorganica e Ingenieria Quimica, Facultad de Ciencias, Campus de Rabanales, Edificio Marie Curie, Universidad de Cordoba, 14071 Cordoba (Spain); Sanchez, L. [Departamento de Quimica Inorganica e Ingenieria Quimica, Facultad de Ciencias, Campus de Rabanales, Edificio Marie Curie, Universidad de Cordoba, 14071 Cordoba (Spain)]. E-mail: luis-sanchez@uco.es; Martin, F. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Universidad de Malaga (Spain); Ramos-Barrado, J.R. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Universidad de Malaga (Spain); Sanchez, M. [Laboratorio de Materiales y Superficie (Unidad Asociada al CSIC), Universidad de Malaga (Spain)

2005-03-01

97

Use of low-temperature nanostructured CuO thin films deposited by spray-pyrolysis in lithium cells  

International Nuclear Information System (INIS)

Nanostructured CuO thin films were prepared by spray pyrolysis of aqueous copper acetate solutions at temperatures over 200-300 deg C range. The textural and structural properties of the films were determined by scanning electron microscopy, atomic force microscopy, X-ray diffraction spectroscopy and X-ray photoelectron spectroscopy (XPS). Although the sole crystalline phase detected in the film was CuO, XPS spectra revealed a more complex surface structure due to the presence of undecomposed copper acetate that can be easily removed by Ar+ ion sputtering. The heating temperature was found to have little limited effect on the particle size and thickness of the films, which, however, increased significantly increasing deposition time. The film with the smallest grain size exhibited an excellent electrochemical response in Li battery electrodes and was capable of supplying sustained specific capacity as high as 625 A h kg-1 (50% greater than that delivered by bulk CuO and close to the theoretical capacity for the CuOCu reaction) upon extensive cycling.

2005-03-01

98

PYROLYSIS OF WOODY MATERIAL  

Directory of Open Access Journals (Sweden)

Full Text Available This work aimed to study the recovery of beech wood by the process of pyrolysis. The effects ofexperimental conditions in products yield and composition were studied. The thermal behaviour offorestry biomass was studied in a batch reactor at temperatures ranging from 350oC to 450oC. Thereaction time of wood thermal degradation took 95 min. The main objective was the identificationof the oxygenates and carbonaceous species generated by pyrolysis of beech wood. The productsof wood cracking were classified into three groups : 25.1 %wt. of gas, 44.3 %wt. of liquids and30.6 %wt. of carbon solid residues. There is considerable experimental evidence that suggests thatthere is competition between gas, liquids and char during wood pyrolysis which depends on theheating conditions.

Martin Bajus

2010-01-01

99

Biomass pyrolysis. Pyrolyse von Biomasse  

Energy Technology Data Exchange (ETDEWEB)

Alongside combustion and gasification the pyrolysis of biomass can be looked upon as an attractive alternative for the production of gas and oil. Special procedures using very short pyrolysis times lead to extensive (app. 80%) conversion of wood, for example, into organic liquids. Because of their very high heat- and mass-transfer rates, fluidized bed processes are predestined for this purpose. Longer residence times at higher temperatures raise the overall gas yield and exert a positive effect on defunctionalization of the oil compounds. Apart from the production of charcoal, the pyrolysis of biomass has so far not been run economically, however. The situation will become quite different as soon as this method of disposal itself attracts major attention. In this respect, the pyrolysis of sewage sludge shows considerable promise as a thermal process, because heavy metals can hardly be eluted from the pyrolysis residue and in addition good fuel gases and useful oils are produced. (orig.).

Kaminsky, W. (Hamburg Univ. (Germany, F.R.). Inst. fuer Technische und Makromolekulare Chemie (ITMCh))

1989-10-01

100

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

 
 
 
 
101

Fluidised bed pyrolysis and catalytic pyrolysis of scrap tyres.  

Science.gov (United States)

Pyrolysis of scrap tyres was undertaken in a semi-continuous fluidised bed reactor in relation to the temperature of the fluidised bed. Subsequently, a fixed bed of Zeolite catalyst was placed in the freeboard of the reactor. The catalyst temperature was held constant at 500 degrees C and the influence of the temperature of the fluidised bed over the same temperature range as the uncatalysed pyrolysis examined. Two Zeolite catalysts were examined, a Y-type Zeolite catalyst and Zeolite ZSM-5 catalyst of differing pore size and surface activity. The main aim of the work was to examine the production of certain single ring aromatic compounds in the derived pyrolysis oil which are known to be of commercial value. The oils were therefore analysed in detail to determine the concentration of benzene, toluene, xylenes and limonene. In addition, detailed analyses of the derived gases under pyrolysis and catalytic pyrolysis conditions were determined. The influence of the temperature of pyrolysis was to increase the yield of benzene, toluene and xylenes but decrease the yield of limonene. In the presence of the catalyst, the yield of oil was reduced with a consequent increase in the gas yield. Benzene, toluene and xylenes present in the oils showed a significant increase in the presence of both of the catalysts. The two catalysts used, although of differing surface acidities and selective pore sizes, produced similar concentrations of benzene, toluene, xylene and limonene. PMID:12916844

Williams, P T; Brindle, A J

2003-07-01

102

Characterization of the pyrolysis oil produced in the slow pyrolysis of sunflower-extracted bagasse  

Energy Technology Data Exchange (ETDEWEB)

Sunflower (Helianthus annus L.)-extracted bagasse pyrolysis experiments were performed in a fixed-bed reactor. The effects of heating rate, final pyrolysis temperature, particle size and pyrolysis atmosphere on the pyrolysis product yields and chemical compositions have been investigated. The maximum oil yield of 23% was obtained in N{sub 2} atmosphere at a pyrolysis temperature of 550 {sup o}C and a heating rate of 7 {sup o}C min {sup -1}. The chemical characterisation has shown that the oil obtained from sunflower-extracted bagasse may be potentially valuable as fuel and chemical feedstocks. (Author)

Yorgun, S.; Sensoz, S. [Osmangazi Univ., Eskisehir (Turkey). Dept. of Chemical Engineering; Kockar, O.M. [Anadolu Univ., Eskisehir (Turkey). Dept. of Chemical Engineering

2001-07-01

103

Jet-fuel deoxygenation. Interim report, March 1987-July 1988  

Energy Technology Data Exchange (ETDEWEB)

This program was initiated to identify and characterize methods of deoxygenating quantities of jet fuel to improve fuel thermal stability. Three methods - chemical getters, molecular sieves and nitrogen sparging - were evaluated. In the case of nitrogen sparging, additional results were obtained by comparing laboratory experimental results with the output from ULLAGE, a computer-based mathematical model. Each method was shown to reduce the oxygen content of jet fuel. Economic and system considerations favor nitrogen sparging for large quantities of fuel. Jet fuels, Deoxygenation. (mjm)

Darrah, S.

1988-10-01

104

Pyrolysis of poplar bark  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of poplar bark is investigated in the temperature range of 573 to 1023 K. The effect of temperature on the gas production rate, gas yield and composition, calorific value of gaseous products and carbon conversion is reported. Production of CO, CH/sub 4/ and CO/sub 2/ can be predicted by a model based on the assumption that reaction is the rate controlling step. 5 figures, 1 table.

Kumar, A.; Mann, R.S.

1982-12-01

105

Shape diversity in particles obtained by low temperature pyrolysis of ferrocene  

Energy Technology Data Exchange (ETDEWEB)

Synthesis experiments, made in a hermetically closed steel container through pyrolytical decomposition of various mixtures like ferrocene and xylene; ferrocene and water; ferrocene, xylene and water in different ratios have resulted in emergence of different in shape particles. The necessary for the realization of each experiment temperature increases linearly with 20 K/min up to the needed temperature and decreases mostly with no delay with a cooling rate of 30 K/min down to room temperature. The obtained particles are shaped as spheres, entirely or partially finished octahedrons or resemble stars. The spheres are perfect in shape and consist of pure incompletely graphitized carbon. The octahedron and star-like shaped particles, synthesized in the presence of ferrocene as precursor, have magnetite nuclei and carbon coating. Particle morphology has been examined by Scanning (SEM) and Transmission Electron Microscopy (TEM) and their chemical composition and crystal structure by the means of X-ray diffraction (XRD), Moessbauer spectroscopy and Electron Probe X-ray Micro Analysis and Energy Dispersive X-ray Spectrometry (EDS). Based on the results obtained it has been concluded that the synthesized particle morphology depends on the simultaneous proceeding magnetite crystal growing and crystal coating with partially graphitized carbon deposit. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Koprinarov, N.; Konstantinova, M. [Central Lab of Solar Energy and New Energy Sources - Bulgarian Academy of Sciences (Bulgaria)

2011-07-15

106

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

107

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)

[en] 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

2005-01-01

108

Evolution of carbon microstructures during the pyrolysis of Turkish Elbistan lignite in the temperature range 700-1000{sup o}C  

Energy Technology Data Exchange (ETDEWEB)

Chars and activated carbons were produced from raw, HCl-washed, and HCl/HF-washed Elbistan lignites at 700, 800, 900, and 1000{sup o} C. The pyrolysis and activation reactions increased the BET areas (m{sup 2}/g carbon) of the acid-washed samples almost 10-fold. The increase of the BET areas (m{sup 2}/g carbon) by increasing the temperature of pyrolysis or activation from 700 to 1000{sup o}C was explained with the burn-out of carbon which led to the development of porosity. The values of the stacking heights, L{sub c} of HCl/HF-washed samples seemed to increase from 1.0 nm to 1.5 nm, the average number of graphene sheets increased from 2.8 to 4.4, and the lateral size of the crystallites, L{sub a}, increased very faintly from 5.0 nm to 5.5 nm when the pyrolysis temperature was increased from 700 to 1000{sup o} C. Activation reactions performed at the same temperature range did not change the stacking heights. The values of L{sub c} for activated HCl/HF-washed samples stayed almost constant in the same range as for the carbonized samples within 1.0-1.5 nm. This indicated that oxidative reactions during activation did not alter the stacking heights of the crystallites significantly in the temperature range of 700-1000{sup o}C. The results presented in the present work can be considered as indications for the development of turbostratic (fully disordered) structures in the temperature range of 700-1000{sup o}C. 21 refs., 12 figs., 3 tabs.

Billur Sakintuna; Yuda Yurum; Sevil Cetinkaya [Sabanci University, Istanbul (Turkey). Faculty of Engineering and Natural Sciences

2004-06-01

109

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

110

Pyrolysis heater  

Energy Technology Data Exchange (ETDEWEB)

The first half and preferably only the first quarter of a pyrolysis coil for treating hydrocarbons is provided with extended heating surface for increasing the adsorption of radiant heat. The extended heating surface may be on the inside or the outside of the tubes and may be in the form of fins or ribs.

Fernandez-Baujin, J.M.; Albano, J.V.; Rhoe, A.; Sundaram, K.M.; Sumner, C.

1989-03-08

111

Laser schlieren, shock tube studies of high temperature hydrocarbon pyrolysis rates. Progress report, June 1, 1980-January 31, 1981  

Energy Technology Data Exchange (ETDEWEB)

Progress during the period has been in five areas: completion of a rigorous physical optics study of laser-schlieren measurements, completion of a study showing that angled laser beam refraction by the shock front can give accurate values for total density change, continuation of a study of the induction time for CO/sub 2/ dissociation, improvements in equipment, and near completion of an extensive study of propane pyrolysis. The propane pyrolysis study has provided rates for the primary step C/sub 3/H/sub 8/ ..-->.. CH/sub 3/ + C/sub 2/H/sub 5/ over the range 1400 to 2400/sup 0/K.

Kiefer, J.H.

1981-01-01

112

DEOXYGENATION OF FATTY ACIDS FOR PREPARATION OF HYDROCARBONS  

UK PubMed Central (United Kingdom)

Embodiments of methods for making renewable diesel by deoxygenating (decarboxylating/decarbonylating/dehydrating) fatty acids to produce hydrocarbons are disclosed. Fatty acids are exposed to a catalyst selected from a) Pt and MO3 on ZrO2 (M is W, Mo, or a combination thereof), or b) Pt/Ge or Pt/Sn on carbon, and the catalyst decarboxylates at least 10% of the fatty acids. In particular embodiments, the catalyst consists essentially of 0.7 wt % Pt and 12 wt % WO3, relative to a mass of catalyst, or the catalyst consists essentially of a) 5 wt % Pt and b) 0.5 wt % Ge or 0.5 wt % Sn, relative to a mass of catalyst. Deoxygenation is performed without added hydrogen and at less than 100 psi. Disclosed embodiments of the catalysts deoxygenate at least 10% of fatty acids in a fatty acid feed, and remain capable of deoxygenating fatty acids for at least 200 minutes to more than 350 hours.

HALLEN RICHARD T; ALBRECHT KARL O; BROWN HEATHER M; WHITE JAMES F

113

Metal-catalyzed selective deoxygenation of diols to alcohols  

Energy Technology Data Exchange (ETDEWEB)

This presentation considered the use of biomass as an alternative feedstock. In particular, it examined the use of carbohydrates (or polyols) as organic raw materials. Carbohydrates represent 95 per cent of the 200 tons of annually regrown biomass. Only 3 per cent is consumed by humans and the remainder is left to decay. As a feedstock, carbohydrates are cheap, abundant and renewable. The disadvantage is that they are over functionalized with OH groups, and organic preparation must be improved. Selective deoxygenation may be a viable method to convert polyols into useful chemicals. This paper proposed a model for such a process. Deoxygenation of diols was examined in terms of OH functionalities. The ruthenium complex was reacted under hydrogen in the presence of HOTf to homogeneously catalyze the selective reductive deoxygenation of 1,2-propanediol to n-propanol. The reaction showed high selectivity for deoxygenation of secondary alcohol over primary alcohol. A new pathway involving a highly acidic dihydrogen complex was proposed. The catalytic method provides a new and quicker way to chemically convert biomass. 20 figs.

Bullock, R.M.; Schlaf, M.; Ghosh, P. [Brookhaven National Lab., Upton, NY (United States); Fagan, P.; Hauptman, E. [Dupont Central Research and Development Dept., Wilmington, DE (United States)

2003-07-01

114

Catalytic Oxidation and Deoxygenation of Renewables with Rhenium Complexes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

115

Batch to flow deoxygenation using visible light photoredox catalysis.  

UK PubMed Central (United Kingdom)

Herein we report a one-pot deoxygenation protocol for primary and secondary alcohols developed via the combination of the Garegg-Samuelsson reaction, visible light-photoredox catalysis, and flow chemistry. This procedure is characterized by mild reaction conditions, easy-to-handle reactants and reagents, excellent functional group tolerance, and good yields.

Nguyen JD; Reiss B; Dai C; Stephenson CR

2013-05-01

116

Sickle-cell hemoglobin: fall in osmotic pressure upon deoxygenation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Macromolecules such as hemoglobin exert both kinetic and matrix effects on osmotic pressure. The kinetic osmotic pressure of sickle-cell hemoglobin is lost upon deoxygenation at physiological erythrocyte concentrations. The non-kinetic or matrix component of osmotic pressure remains relatively uncha...

Hargens, A R; Bowie, L J; Lent, D; Carreathers, S; Peters, R M; Hammel, H T; Scholander, P F

117

Batch to flow deoxygenation using visible light photoredox catalysis.  

Science.gov (United States)

Herein we report a one-pot deoxygenation protocol for primary and secondary alcohols developed via the combination of the Garegg-Samuelsson reaction, visible light-photoredox catalysis, and flow chemistry. This procedure is characterized by mild reaction conditions, easy-to-handle reactants and reagents, excellent functional group tolerance, and good yields. PMID:23142826

Nguyen, John D; Reiss, Barbara; Dai, Chunhui; Stephenson, Corey R J

2012-11-12

118

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin  

International Nuclear Information System (INIS)

[en] 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

1997-10-28

119

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

120

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

UK PubMed Central (United Kingdom)

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.

Singh BP; Cowie AL; Smernik RJ

2012-11-01

 
 
 
 
121

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

2012-10-10

122

Pyrolysis of tyres. Influence of the final temperature of the process on emissions and the calorific value of the products recovered  

International Nuclear Information System (INIS)

A study was made of the pyrolysis of tyre particles, with the aim of determining the possibilities of using the products resulting from the process as fuel. Three final temperatures were used, determined from thermogravimetric data. The design of the experiment was a horizontal oven containing a reactor into which particles of the original tyre were placed. After the process, a solid fraction (char) remained in the reactor, while the gases generated went through a set of scrubbers where most of the condensable fraction (oils) was retained. Finally, once free of this fraction, the gases were collected in glass ampoules. Solid and liquids fractions were subjected to thermogravimetric analyses in order to study their combustibility. The gas fraction was analysed by means of gas chromatography to establish the content of CO, CO2, H2 and hydrocarbons present in the samples (mainly components of gases produced in the pyrolysis process). A special study was made of the sulphur and chlorine content of all the fractions, as the presence of these elements could be problematic if the products are used as fuel. Tyre pyrolysis engenders a solid carbon residue that concentrates sulphur and chorine, with a relatively high calorific value, although not so high as that of the original tyre. The liquid fraction produced by the process has a high calorific value, which rises with the final temperature, up to 40 MJ/kg. The chlorine content of this fraction is negligible. Over 95% of the gas fraction, regardless of the final temperature, is composed of hydrocarbons of a low molecular weight and hydrogen, this fraction also appearing to be free of chlorine.

2004-01-01

123

Pyrolysis of tyres. Influence of the final temperature of the process on emissions and the calorific value of the products recovered.  

Science.gov (United States)

A study was made of the pyrolysis of tyre particles, with the aim of determining the possibilities of using the products resulting from the process as fuel. Three final temperatures were used, determined from thermogravimetric data. The design of the experiment was a horizontal oven containing a reactor into which particles of the original tyre were placed. After the process, a solid fraction (char) remained in the reactor, while the gases generated went through a set of scrubbers where most of the condensable fraction (oils) was retained. Finally, once free of this fraction, the gases were collected in glass ampoules. Solid and liquids fractions were subjected to thermogravimetric analyses in order to study their combustibility. The gas fraction was analysed by means of gas chromatography to establish the content of CO, CO2, H2 and hydrocarbons present in the samples (mainly components of gases produced in the pyrolysis process). A special study was made of the sulphur and chlorine content of all the fractions, as the presence of these elements could be problematic if the products are used as fuel. Tyre pyrolysis engenders a solid carbon residue that concentrates sulphur and chorine, with a relatively high calorific value, although not so high as that of the original tyre. The liquid fraction produced by the process has a high calorific value, which rises with the final temperature, up to 40 MJ/kg. The chlorine content of this fraction is negligible. Over 95% of the gas fraction, regardless of the final temperature, is composed of hydrocarbons of a low molecular weight and hydrogen, this fraction also appearing to be free of chlorine. PMID:15120430

Díez, C; Martínez, O; Calvo, L F; Cara, J; Morán, A

2004-01-01

124

Effect of substrate temperature on the structural and optical properties of MoO3 thin films prepared by spray pyrolysis technique  

International Nuclear Information System (INIS)

[en] Thin films of Molybdenum oxide were prepared by spray pyrolysis technique on glass substrates, by using 0.1 M of molybdenum chloride (MoCl5) dissolved in deionized water. Influence of substrate temperature on structural and optical properties is studied in the range from 200 to 300 deg. C. The prepared samples correspond to MoO3 phase with orientation and crystallites size which are modified by deposition temperature, the films prepared at 200 deg. C are monoclinic and the films prepared in the range from 250 to 300 deg. C are polycrystalline with orthorhombic symmetry. The samples present transmission coefficient and optical gap which vary as function of substrate temperature. Gap energy is located between 3.14 and 3.34 eV depending on the substrate temperature

2003-01-15

125

Effect of substrate temperature on the structural and optical properties of MoO{sub 3} thin films prepared by spray pyrolysis technique  

Energy Technology Data Exchange (ETDEWEB)

Thin films of Molybdenum oxide were prepared by spray pyrolysis technique on glass substrates, by using 0.1 M of molybdenum chloride (MoCl{sub 5}) dissolved in deionized water. Influence of substrate temperature on structural and optical properties is studied in the range from 200 to 300 deg. C. The prepared samples correspond to MoO{sub 3} phase with orientation and crystallites size which are modified by deposition temperature, the films prepared at 200 deg. C are monoclinic and the films prepared in the range from 250 to 300 deg. C are polycrystalline with orthorhombic symmetry. The samples present transmission coefficient and optical gap which vary as function of substrate temperature. Gap energy is located between 3.14 and 3.34 eV depending on the substrate temperature.

Bouzidi, A.; Benramdane, N.; Tabet-Derraz, H.; Mathieu, C.; Khelifa, B.; Desfeux, R

2003-01-15

126

Shock tube pyrolysis of pyridine  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of pyrolysis of pyridine dilute in argon have been studied in a single-pulse, shock tube, using capillary column GC together with GC/MS and FTIR spectroscopy for product determination, over the temperature range of 1,300-1,800 K and total pressures of 7-11 atm. At the lower end of the studied temperatures, cyanoacetylene was found to be the principal nitrogen-containing product. At elevated temperature hydrogen cyanide predominated. Other major products were acetylene and hydrogen. Several sources of HCN were identified in the system. An important source of HCN at high temperatures is the addition of H atoms to cyano compounds, especially cyanoacetylene, but also acetonitrile and acrylonitrile which are produced in the pyrolysis. The pyrolysis is a chain process initiated principally by C-H bond fission to form o-pyridyl. A 58-step reaction model is presented and shown to substantially fit the observed profiles of the major product species.

Mackie, J.C. (Univ. of Sydney, New South Wales (Australia)); Colket, M.B. III (United Technologies Research Center, Hartford, CT (USA)); Nelson, P.F. (CSIRO, North Ryde, New South Wales (Australia))

1990-05-17

127

Flash pyrolysis of aspen-poplar wood  

Energy Technology Data Exchange (ETDEWEB)

A continuous fluidized bed bench scale flash pyrolysis unit operating at atmospheric pressure and feed rates of about 15 g/h has been successfully designed and operated. A unique solids feeder capable of delivering constant low rates of biomass has also been developed. Extensive pyrolysis tests with hybrid aspen-popular sawdust (105-250 mu) have been carried out to investigate the effects of temperature, particle size, pyrolysis atmosphere and wood pretreatment on yields of tar, organic liquids, gases and char. At optimum pyrolysis conditions high tar yields of up to 65% of the dry wood weight fed are possible at residence times of less than one second.

Scott, D.S.; Piskorz, J.

1982-10-01

128

Oxidation and low temperature properties of biofuels obtained from pyrolysis and alcoholysis of soybean oil and their blends with petroleum diesel  

Energy Technology Data Exchange (ETDEWEB)

Diesel-like fuels were synthesized by a pyrolysis method using soybean oil (pyrodiesel, PD) and soybean soapstock (SPD), respectively, as starting material. These pyrodiesel samples were compared with soy biodiesel (BD) samples. All these three biofuels (PD, SPD and BD) and their blends with high sulfur (HSD) and low sulfur (LSD) diesel fuels were evaluated by measuring a number of fuel properties, such as oxidative stability, low-temperature performance, acid value and corrosion properties. Compared to BD blends, PD and SPD and their blends were found to have better oxidative stability, though inferior acid values. SPD and its blends have better flow performance at low-temperature compared to BD and PD blends. All the biofuels and their blends met the copper corrosion requirement prescribed by US and European standard. Based on the results reported here, pyrodiesels from these two-different feedstocks have potential and will require some upgrading or change in pyrolysis conditions, if they are to be used as fuel blending component. (author)

Sharma, Brajendra K. [Food and Industrial Oil Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815N. University St., Peoria, IL 61604 (United States); Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Suarez, Paulo A.Z. [Food and Industrial Oil Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815N. University St., Peoria, IL 61604 (United States); LMC-IQ, Universidade de Brasilia, CP 4478, CEP 70919-970, Brasilia-DF (Brazil); Perez, Joseph M. [Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Erhan, Sevim Z. [Food and Industrial Oil Research Unit, National Center for Agricultural Utilization Research, United States Department of Agriculture, Agricultural Research Service, 1815N. University St., Peoria, IL 61604 (United States)

2009-10-15

129

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

Science.gov (United States)

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 °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) chloride, indium (III) chloride and thiourea for synthesis on heated glass substrates.

Mahendran, C.; Suriyanarayanan, N.

2010-04-01

130

Fragmentation of N-oxides (deoxygenation) in atmospheric pressure ionization: investigation of the activation process.  

UK PubMed Central (United Kingdom)

The diagnostic fragmentation of N-oxides resulting from loss of the oxygen atom (MH+ --> MH+-O) in electrospray and atmospheric pressure chemical ionization (APCI) mass spectra was investigated. When the temperature of the heated capillary tube was elevated, the ratio of the intensity of the [MH+ -16] fragment to the precursor ion (MH+) increased. This 'deoxygenation' process was associated with thermal activation and did not result from collisional activation in the desolvation region of the API source. Although the extent of 'deoxygenation' is compound-dependent, it can provide evidence for the presence of an N-oxide in a sample and can be used to distinguish N-oxides from hydroxylated metabolites (Ramanathan et al. Anal. Chem. 2000; 72: 1352). To demonstrate the practical application of thermal fragmentation of N-oxides, liquid chromatography (LC)/APCI-MS was used to distinguish an N-oxide drug from its hydroxylated metabolite in an unprocessed rat urine sample, despite the fact that the drug and its metabolite were not fully resolved by HPLC.

Tong W; Chowdhury SK; Chen JC; Zhong R; Alton KB; Patrick JE

2001-01-01

131

Influence of catalyst weight/biomass flow rate ratio on gas production in the catalytic pyrolysis of pine sawdust at low temperatures  

Energy Technology Data Exchange (ETDEWEB)

Pine sawdust catalytic pyrolysis has been studied in a fluidized bed at temperatures of 650 and 700 C. The experimental work was carried out in a bench-scale plant based on Waterloo Fast Pyrolysis Process (WFPP) technology. The Ni-Al catalyst used was prepared by coprecipitation with a molar ratio 1:2 (NI-Al) and calcined at 750 C for 3 h. The catalyst was not reduced prior to the biomass reaction. The influence of the catalyst weight/biomass flow rate ratio (W/mb) on the product distribution and on the quality of the gas product obtained was analyzed. An increase of the W/mb ratio increases the total gas yield and diminishes the liquid yield. When the W/mb ratio increases, H{sub 2} and CO yields increase while CO{sub 2}, CH{sub 4}, and C{sub 2} yields decrease. For W/mb ratios {ge} 0.4 h, no significant modifications are observed on the initial yields of different gases, and it is confirmed that under these conditions the initial gas composition is similar to that for thermodynamic equilibrium. For W/mb ratios < 0.4 h, a simple first-order kinetic equation has been suggested for H{sub 2} and CO formation.

Garcia, L.; Salvador, M.L.; Arauzo, J.; Bilbao, R. [Univ. of Zaragoza (Spain). Dept. of Chemical and Environmental Engineering

1998-10-01

132

Assessment of Waterloo flash pyrolysis process to obtain liquid fuels from Canadian peat  

Energy Technology Data Exchange (ETDEWEB)

A program was undertaken to evaluate the yields of liquids and other products obtainable from Canadian peats using the Waterloo Fast Pyrolysis Process (WFPP). A secondary objective was to investigate the short residence time fluidized bed as a dryer for milled peat. The pyroysis tests were carried out in the 1-3 kg/h pilot plant unit developed for biomass pyrolysis, in order to yield sufficient quantities of liquid for adequate characterization. Yields of organic liquids of about 45% to 47% of the moisture-free feed were obtained in the optimum temperature range of 450 degree to 550 degree with a younger long fibre sphagnum peat. Char yields decreased from 35% to 26% while gas yilds increased from 12% to 17% over the optmum temperature range. CO and CO{sub 2} were the main gaseous products. The character of the liquid product changed significantly over the optimum temperature range. The ratio of water soluble to water insoluble components changed from 2.3 to about 0.6, with some corresponding decrease in oxygen content. A considerable number of the individual components were identified chromatographically. The short residence time fluid bed dryer was very efficient when tested for four grades of Quebec peat. For all but old decomposed black peat, which was more difficult to dry, with critical moisture contents of about 13%. Good yields of organic liquids can be obtained from yellow or brown peats using WFPP. These liquids have a lower oxygen content than oils from wood, and contain some longer chain paraffinic compounds. Upgrading tests showed that good yields of a gasoline-like liquid could be obtained by a catalytic deoxygenation-hydrogenation process. 17 refs., 36 figs., 3 tabs.

Scott, D.S.

1988-06-01

133

Molecular products from the pyrolysis and oxidative pyrolysis of tyrosine.  

Science.gov (United States)

The thermal degradation of tyrosine at a residence time of 0.2s was conducted in a tubular flow reactor in flowing N2 and 4% O2 in N2 for a total pyrolysis time of 3min. The fractional pyrolysis technique, in which the same sample was heated continuously at each pyrolysis temperature, was applied. Thermal decomposition of tyrosine between 350 and 550°C yielded predominantly phenolic compounds (phenol, p-cresol, and p-tyramine), while decomposition between 550 and 800°C yielded hydrocarbons such as benzene, toluene, and ethyl benzene as the major reaction products. For the first time, the identification of p-tyramine, a precursor for the on of formation of p-tyramine and its degradation to phenol and p-cresol, and toxicological discussion of some of the harmful reaction products is also presented. PMID:23490178

Kibet, Joshua K; Khachatryan, Lavrent; Dellinger, Barry

2013-03-11

134

Molecular products from the pyrolysis and oxidative pyrolysis of tyrosine.  

UK PubMed Central (United Kingdom)

The thermal degradation of tyrosine at a residence time of 0.2s was conducted in a tubular flow reactor in flowing N2 and 4% O2 in N2 for a total pyrolysis time of 3min. The fractional pyrolysis technique, in which the same sample was heated continuously at each pyrolysis temperature, was applied. Thermal decomposition of tyrosine between 350 and 550°C yielded predominantly phenolic compounds (phenol, p-cresol, and p-tyramine), while decomposition between 550 and 800°C yielded hydrocarbons such as benzene, toluene, and ethyl benzene as the major reaction products. For the first time, the identification of p-tyramine, a precursor for the on of formation of p-tyramine and its degradation to phenol and p-cresol, and toxicological discussion of some of the harmful reaction products is also presented.

Kibet JK; Khachatryan L; Dellinger B

2013-05-01

135

Manipulating catalytic pathways: deoxygenation of palmitic acid on multifunctional catalysts.  

Science.gov (United States)

The mechanism of the catalytic reduction of palmitic acid to n-pentadecane at 260 °C in the presence of hydrogen over catalysts combining multiple functions has been explored. The reaction involves rate-determining reduction of the carboxylic group of palmitic acid to give hexadecanal, which is catalyzed either solely by Ni or synergistically by Ni and the ZrO2 support. The latter route involves adsorption of the carboxylic acid group at an oxygen vacancy of ZrO2 and abstraction of the ?-H with elimination of O to produce the ketene, which is in turn hydrogenated to the aldehyde over Ni sites. The aldehyde is subsequently decarbonylated to n-pentadecane on Ni. The rate of deoxygenation of palmitic acid is higher on Ni/ZrO2 than that on Ni/SiO2 or Ni/Al2O3, but is slower than that on H-zeolite-supported Ni. As the partial pressure of H2 is decreased, the overall deoxygenation rate decreases. In the absence of H2, ketonization catalyzed by ZrO2 is the dominant reaction. Pd/C favors direct decarboxylation (-CO2), while Pt/C and Raney Ni catalyze the direct decarbonylation pathway (-CO). The rate of deoxygenation of palmitic acid (in units of mmol moltotal metal(-1) h(-1)) decreases in the sequence r(Pt black) ?r(Pd black) >r(Raney Ni) in the absence of H2 . In situ IR spectroscopy unequivocally shows the presence of adsorbed ketene (C=C=O) on the surface of ZrO2 during the reaction with palmitic acid at 260 °C in the presence or absence of H2. PMID:23519964

Peng, Baoxiang; Zhao, Chen; Kasakov, Stanislav; Foraita, Sebastian; Lercher, Johannes A

2013-03-20

136

Manipulating catalytic pathways: deoxygenation of palmitic acid on multifunctional catalysts.  

UK PubMed Central (United Kingdom)

The mechanism of the catalytic reduction of palmitic acid to n-pentadecane at 260 °C in the presence of hydrogen over catalysts combining multiple functions has been explored. The reaction involves rate-determining reduction of the carboxylic group of palmitic acid to give hexadecanal, which is catalyzed either solely by Ni or synergistically by Ni and the ZrO2 support. The latter route involves adsorption of the carboxylic acid group at an oxygen vacancy of ZrO2 and abstraction of the ?-H with elimination of O to produce the ketene, which is in turn hydrogenated to the aldehyde over Ni sites. The aldehyde is subsequently decarbonylated to n-pentadecane on Ni. The rate of deoxygenation of palmitic acid is higher on Ni/ZrO2 than that on Ni/SiO2 or Ni/Al2O3, but is slower than that on H-zeolite-supported Ni. As the partial pressure of H2 is decreased, the overall deoxygenation rate decreases. In the absence of H2, ketonization catalyzed by ZrO2 is the dominant reaction. Pd/C favors direct decarboxylation (-CO2), while Pt/C and Raney Ni catalyze the direct decarbonylation pathway (-CO). The rate of deoxygenation of palmitic acid (in units of mmol moltotal metal(-1) h(-1)) decreases in the sequence r(Pt black) ?r(Pd black) >r(Raney Ni) in the absence of H2 . In situ IR spectroscopy unequivocally shows the presence of adsorbed ketene (C=C=O) on the surface of ZrO2 during the reaction with palmitic acid at 260 °C in the presence or absence of H2.

Peng B; Zhao C; Kasakov S; Foraita S; Lercher JA

2013-04-01

137

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

138

Low-temperature co-pyrolysis of a low-rank coal and biomass to prepare smokeless fuel briquettes  

Energy Technology Data Exchange (ETDEWEB)

Smokeless fuel briquettes have been prepared with low-rank coal and biomass. These raw materials have been mixed in different ratios and have been pyrolysed at 600C with the aim to reduce both the volatile matter and the sulphur content, and to increase the high calorific value (HCV). The co-pyrolysis of coal and biomass has shown a synergetic effect. The biomass favours the release of hydrogen sulphide during the thermal treatment. This fact can be explained in terms of the hydrogen-donor character of the biomass. Moreover, the optimisation of the amount of binder and the influence of different types of biomass in the blend have been studied with respect to the mechanical properties of the briquettes (impact resistance, compression strength and abrasion). Briquettes prepared with sawdust (S) present better mechanical properties than those with olive stones (O) because of its fibrous texture.

Blesa, M.J.; Miranda, J.L.; Moliner, R.; Izquierdo, M.T. [Instituto de Carboquimica CSIC, P.O. Box 589, 50080 Zaragoza (Spain); Palacios, J.M. [Instituto de Catalisis y Petroleoquimica CSIC, Cantoblanco, 28049 Madrid (Spain)

2003-12-01

139

Modeling CFB biomass pyrolysis reactors  

International Nuclear Information System (INIS)

[en] Fluidized bed-fast pyrolysis of biomass is considered as having a high commercial potential for the thermal treatment of biomass. This paper mainly presents a model developed further to improvements in the understanding of the science, and capable of predicting pyrolysis yields that are in satisfactory agreement with literature data. The kinetics and endothermicity of biomass pyrolysis are reviewed from extensive TGA and differential scanning calorimetry experiments. For most biomass species, the reaction rate constant is >0.5 s-1, corresponding to a fast reaction, so the requirement of a short reaction time for a high conversion can be met. Lab-scale batch experiments and pilot-scale CFB experiments show that an oil yield between 60 and 70 wt% can be achieved at an operating temperature of 510±10 oC, in line with literature data. Pyrolysis fundamentals are the basis of the developed model, applied to predict the yields of the different products as functions of process operation variables. The predictions are in fair agreement with our own conversion experiments and literature data. Finally, all findings are used and are illustrated in the design strategy of a CFB for the pyrolysis of biomass

2008-01-01

140

Modeling CFB biomass pyrolysis reactors  

Energy Technology Data Exchange (ETDEWEB)

Fluidized bed-fast pyrolysis of biomass is considered as having a high commercial potential for the thermal treatment of biomass. This paper mainly presents a model developed further to improvements in the understanding of the science, and capable of predicting pyrolysis yields that are in satisfactory agreement with literature data. The kinetics and endothermicity of biomass pyrolysis are reviewed from extensive TGA and differential scanning calorimetry experiments. For most biomass species, the reaction rate constant is >0.5 s{sup -1}, corresponding to a fast reaction, so the requirement of a short reaction time for a high conversion can be met. Lab-scale batch experiments and pilot-scale CFB experiments show that an oil yield between 60 and 70 wt% can be achieved at an operating temperature of 510{+-}10 C, in line with literature data. Pyrolysis fundamentals are the basis of the developed model, applied to predict the yields of the different products as functions of process operation variables. The predictions are in fair agreement with our own conversion experiments and literature data. Finally, all findings are used and are illustrated in the design strategy of a CFB for the pyrolysis of biomass. (author)

Van de Velden, Manon; Baeyens, Jan [Department of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 25T (United Kingdom); Boukis, Ioannis [Helector Ltd., Kritis and Gravias 12, Agryroupolis, Athens (Greece)

2008-02-15

 
 
 
 
141

Modeling CFB biomass pyrolysis reactors  

Energy Technology Data Exchange (ETDEWEB)

Fluidized bed-fast pyrolysis of biomass is considered as having a high commercial potential for the thermal treatment of biomass. This paper mainly presents a model developed further to improvements in the understanding of the science, and capable of predicting pyrolysis yields that are in satisfactory agreement with literature data. The kinetics and endothermicity of biomass pyrolysis are reviewed from extensive TGA and differential scanning calorimetry experiments. For most biomass species, the reaction rate constant is >0.5 s{sup -1}, corresponding to a fast reaction, so the requirement of a short reaction time for a high conversion can be met. Lab-scale batch experiments and pilot-scale CFB experiments show that an oil yield between 60 and 70 wt% can be achieved at an operating temperature of 510{+-}10 {sup o}C, in line with literature data. Pyrolysis fundamentals are the basis of the developed model, applied to predict the yields of the different products as functions of process operation variables. The predictions are in fair agreement with our own conversion experiments and literature data. Finally, all findings are used and are illustrated in the design strategy of a CFB for the pyrolysis of biomass.

Velden, Manon van de [Department of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 25T (United Kingdom); Baeyens, Jan [Department of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 25T (United Kingdom)], E-mail: j.baeyens@bham.ac.uk; Boukis, Ioannis [Helector Ltd., Kritis and Gravias 12, Agryroupolis, Athens (Greece)

2008-02-15

142

Production and characterization of pyrolysis oils from Euphorbia macroclada  

Energy Technology Data Exchange (ETDEWEB)

In this work, Euphorbia macroclada were pyrolyzed in a laboratory-scale fixed bed reactor. The influence of final pyrolysis temperature, heating rate, and pyrolysis atmosphere on the product yields was investigated. Pyrolysis runs were performed using reactor temperatures ranging between 400 and 700{sup o}C with heating rates of 7 and 40{sup o}C/min. The highest liquid yield was obtained at 550{sup o}C pyrolysis temperature with a heating rate of 7{sup o}C/min. The results from the pyrolysis of Euphorbia macroclada showed that the clear increments of the pyrolysis conversion in the temperature interval 500 to 550{sup o}C are due to the rapid devolatilization of cellulose and hemicelluloses. (author)

Tuncel, F.; Gercel, H.F. [Anadolu Univ., Eskisehir (Turkey). Dept. of Chemical Engineering

2004-07-15

143

PYROLYSIS OF TOBACCO RESIDUE: PART 1. THERMAL  

Directory of Open Access Journals (Sweden)

Full Text Available 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 400°C for one sample and at 500°C for the other. The compositions of bio-oils from the pyrolysis of the two samples were found to be very similar. N-containing compounds were found to be the major compounds identified in ether extracts for both samples.

Mehmet K. Akalin; Selhan Karagöz

2011-01-01

144

Laser induced pyrolysis techniques  

International Nuclear Information System (INIS)

The application of laser pyrolysis techniques to the problems of chemical analysis is discussed. The processes occurring during laser pyrolysis are first briefly reviewed. The problems encountered in laser pyrolysis gas chromatography are discussed using the analysis of phenanthrene and binary hydrocarbons. The application of this technique to the characterization of naturally occurring carbonaceous material such as oil shales and coal is illustrated

1976-09-07

145

Corrosivity Of Pyrolysis Oils  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis oils from several sources have been analyzed and used in corrosion studies which have consisted of exposing corrosion coupons and stress corrosion cracking U-bend samples. The chemical analyses have identified the carboxylic acid compounds as well as the other organic components which are primarily aromatic hydrocarbons. The corrosion studies have shown that raw pyrolysis oil is very corrosive to carbon steel and other alloys with relatively low chromium content. Stress corrosion cracking samples of carbon steel and several low alloy steels developed through-wall cracks after a few hundred hours of exposure at 50 C. Thermochemical processing of biomass can produce solid, liquid and/or gaseous products depending on the temperature and exposure time used for processing. The liquid product, known as pyrolysis oil or bio-oil, as produced contains a significant amount of oxygen, primarily as components of water, carboxylic acids, phenols, ketones and aldehydes. As a result of these constituents, these oils are generally quite acidic with a Total Acid Number (TAN) that can be around 100. Because of this acidity, bio-oil is reported to be corrosive to many common structural materials. Despite this corrosive nature, these oils have the potential to replace some imported petroleum. If the more acidic components can be removed from this bio-oil, it is expected that the oil could be blended with crude oil and then processed in existing petroleum refineries. The refinery products could be transported using customary routes - pipelines, barges, tanker trucks and rail cars - without a need for modification of existing hardware or construction of new infrastructure components - a feature not shared by ethanol.

Keiser, James R [ORNL; Bestor, Michael A [ORNL; Lewis Sr, Samuel Arthur [ORNL; Storey, John Morse [ORNL

2011-01-01

146

Study of rapid pyrolysis of brown coal dusts and preliminary results of properties of the pyrolysis gas  

Energy Technology Data Exchange (ETDEWEB)

Evaluates laboratory experiments on rapid pyrolysis of brown coal dust. Pyrolysis temperatures varied between 500 and 1,600 K, using low-grade brown coal and xylite with a dust grain size of 60 to 80 mm. Fuel supply was 5 to 100 g/min. The yield of pyrolysis gas in relation to pyrolysis temperature is analyzed. Components of the gas produced are CO, CO[sub 2], H[sub 2], CH[sub 4], C[sub 2]H[sub 2], C[sub 2]H[sub 4], C[sub 2]H[sub 6], O[sub 2] and soot. At temperatures higher than 1,300 K, 90% of pyrolysis gas consisted of hydrogen and carbon monoxide. Pyrolysis gas produced in the 950 to 1,100 K temperature range had the highest calorific value. 4 refs.

Karcz, H.; Standa, J.; Effenberger, H. (Technische Universitaet, Wroclaw (Poland). Institut fuer Waermetechnik und Stroemungsmechanik)

1992-09-01

147

Waste minimization pretreatment via pyrolysis and oxidative pyrolysis of organic ion exchange resin  

International Nuclear Information System (INIS)

[en] Pyrolysis and/or oxidative pyrolysis of organic ion exchange resins and other combustible waste may be effective pretreatment processes before vitrification. Three different methods were examined with the TGA to pretreat the resins: pyrolysis; oxidative pyrolysis; and oxidative pyrolyses of ash remaining after the pyrolysis of resin. The latter two methods were found to provide better volume reduction than the pyrolysis-only process. Between the two types of resins, cationic and anionic, the cationic exchange resin was less volatile. Pyrolysis and oxidative pyrolysis of mixed resin (50% cation and 50% anion by wt.) showed volatilization at the temperatures where volatilization was observed for each of the separate resins. Because of certain limitations of the commercial TGA, tube furnace experiments were performed, generally, to examine the pyrolysis of larger quantities of cationic, anionic, and mixed resin, and to examine off-gas characteristics. The cationic resin-only and anionic resin-only gravimetric results showed good agreement with the smaller-scale TGA results. SEM pictures of the different variants of the resin (cationic, anionic, and mixed) show a different morphology for each. Off-gas data showed the presence of H2S, SO2, CO, and NO during the pyrolysis of cationic resin. CO was observed during the pyrolysis of anionic resin. The mixed resin trials showed the presence of the gases approximately at the temperatures where the gases would evolve if the results of the two different resins (cationic and anionic) were superimposed. However, the amount of hydrogen sulfide relative to the sulfur dioxide was found to increase significantly compared to the results of the cationic resin-only trials

1998-01-01

148

Pyrolysis and co-pyrolysis of organic wastes, Part one: Co-pyrolysis of solid organic wastes with black coal  

Energy Technology Data Exchange (ETDEWEB)

Evaluates co-pyrolysis of black coal from Czechoslovakia with selected organic solid wastes. Black coal from the Doubrava mine was used: ash content 9.30%, volatile matter 30.31%, vitrinite reflectivity 0.97%, vitrinite content 47%, exinite content 10%, inertinite 43%. Coal was co-pyrolized with the following wastes: polyethylene, polystyrene, dechlorinated PVC, phenol-formaldehyde resins, wooden sawdust, biomass, etc. Co-pyrolysis conditions, pressure, temperature, type of heat carriers (fluidized bed), properties of the initial organic waste, co-pyrolysis products (coke, liquid products, gaseous products), efficiency. Efficiency of low temperature co-pyrolysis of coal with plastic wastes and some other organic wastes was comparatively evaluated. 27 refs.

Straka, P.; Srogl, J. (Ustav Geotechniky, Prague (Czechoslovakia))

1992-10-01

149

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

150

Pyrolysis of composite plastic waste.  

UK PubMed Central (United Kingdom)

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.

Cunliffe AM; Jones N; Williams PT

2003-05-01

151

Reaction pathways for the deoxygenation of vegetable oils and related model compounds.  

UK PubMed Central (United Kingdom)

Vegetable oil-based feeds are regarded as an alternative source for the production of fuels and chemicals. Paraffins and olefins can be produced from these feeds through catalytic deoxygenation. The fundamentals of this process are mostly studied by using model compounds such as fatty acids, fatty acid esters, and specific triglycerides because of their structural similarity to vegetable oils. In this Review we discuss the impact of feedstock, reaction conditions, and nature of the catalyst on the reaction pathways of the deoxygenation of vegetable oils and its derivatives. As such, we conclude on the suitability of model compounds for this reaction. It is shown that the type of catalyst has a significant effect on the deoxygenation pathway, that is, group?10 metal catalysts are active in decarbonylation/decarboxylation whereas metal sulfide catalysts are more selective to hydrodeoxygenation. Deoxygenation studies performed under H2 showed similar pathways for fatty acids, fatty acid esters, triglycerides, and vegetable oils, as mostly deoxygenation occurs indirectly via the formation of fatty acids. Deoxygenation in the absence of H2 results in significant differences in reaction pathways and selectivities depending on the feedstock. Additionally, using unsaturated feedstocks under inert gas results in a high selectivity to undesired reactions such as cracking and the formation of heavies. Therefore, addition of H2 is proposed to be essential for the catalytic deoxygenation of vegetable oil feeds.

Gosselink RW; Hollak SA; Chang SW; van Haveren J; de Jong KP; Bitter JH; van Es DS

2013-09-01

152

Alveolar gas exchange, oxygen delivery and tissue deoxygenation in men and women during incremental exercise.  

Science.gov (United States)

We investigated whether leg and arm skeletal muscle, and cerebral deoxygenation, differ during incremental cycling exercise in men and women, and if women's lower capacity to deliver O2 affects tissue deoxygenation. Men (n=10) compared to women (n=10), had greater cardiac output, which with greater hemoglobin concentration produced greater absolute (QaO2) and body size-adjusted oxygen delivery (QaO2i) at peak exercise. Despite women's lower peak QaO2, their leg muscle deoxygenation was similar at a given work rate and QaO2, but less than in men at peak exercise (?tissue saturation index -27.1 ± 13.2% vs. -11.8 ± 5.7%, P<0.01; ?[deoxyhemoglobin] 15.03 ± 8.57 ?M vs. 3.73 ± 3.98 ?M, P<0.001). At peak exercise, oxygen uptake was associated both with QaO2 and leg muscle deoxygenation (both P<0.01). Arm muscle and cerebral deoxygenation did not differ between sexes at peak exercise. Thus, both high O2 delivery and severe active muscle deoxygenation are determinants of good exercise performance, and active muscle deoxygenation responses are regulated partly in a sex-specific manner with an influence of exercise capacity. PMID:23707876

Peltonen, Juha E; Hägglund, Harriet; Koskela-Koivisto, Tiina; Koponen, Anne S; Aho, Jyrki M; Rissanen, Antti-Pekka E; Shoemaker, J Kevin; Tiitinen, Aila; Tikkanen, Heikki O

2013-05-24

153

Mild pyrolysis of selectively oxidized coals  

Energy Technology Data Exchange (ETDEWEB)

The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter includes the investigation of the mild pyrolysis of unoxidized coals plus a selection of selectively oxidized coals. In addition the effect of particle size and extent of oxidation on pyrolysis was investigated. Some preliminary data concerning pyrolysis under vacuum and ambient pressure was also obtained. Work completed this quarter supports the following conclusions: (1) Desulfurization of unoxidized coals increases with increasing pyrolysis temperature and correlates with the loss of volatile matter. (2) Particle size did not influence the extent of desulfurization significantly. (3) Removing pyrite prior to pyrolysis helps to achieve a lower sulfur product beyond that expected from the removal of pyrite alone. (4) The extent of selective oxidation in teh pretreatment step did not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (5) Up to 84% of the sulfur has been removed from the IBC 101 coal by combining selective oxidation and SCM/base reactions. (6) Evidence for regressive reactions between volatilized sulfur compounds and partially desulfurized products was obtained by studying how changes in pyrolysis pressure effected the product sulfur content.

Hippo, E.J.

1991-01-01

154

Rapid and catalytic pyrolysis of corn stalks  

Energy Technology Data Exchange (ETDEWEB)

Non-catalytic and catalytic rapid pyrolysis of corn stalks was studied in a tubular fixed-bed reactor. The optimum operating conditions giving the highest liquid yield was determined as pyrolysis temperature of 500 C, sweeping gas flow rate of 400 cm{sup 3} min{sup -} {sup 1} and heating rate of 500 C min{sup -} {sup 1}. In the catalytic process, rapid pyrolysis of stalks was performed at the optimum conditions with catalysts such as ZSM-5, HY and USY. The highest liquid yield from the catalytic pyrolysis was 27.55% with ZSM-5, while the oil from non-catalytic pyrolysis was 33.30%. In the last part, various spectroscopic and chromatographic methods were applied for characterization of bio-oils. Although catalytic pyrolysis converts the long chains of alkanes and alkenes of the oils into lower weight hydrocarbons, the obtained oil yields were lower than those of non-catalytic pyrolysis. USY catalyst gives the highest amount of aromatics among the catalysts used. Moreover, TG-DTA analyses were applied on raw materials to investigate thermal degradation of corn stalks and calculate the kinetic parameters. (author)

Uzun, Basak Burcu; Sarioglu, Nuri [Anadolu University, Faculty of Engineering and Architecture, Dept. of Chemical Engineering, iki Eyluel Campus, 26555, Eskisehir (Turkey)

2009-05-15

155

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

156

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.

2008-12-30

157

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.

2012-05-15

158

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

159

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 (RMS˜60 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

160

Decomposition of ion exchange resins by pyrolysis  

International Nuclear Information System (INIS)

Pyrolysis of spent ion exchange resins is one of the most effective methods for reducing radioactive waster volume and for making the final waste form more stable. Fundamental experiments were performed to clarify the pyrolysis characteristics of anion and cation exchange resins. Residual elemental analyses and off-gas analyses showed that the decomposition ratio of cation resins was only 50 wt% at 6000C, while that of anion resins was 90 wt% at 4000C. Infrared spectroscopy for cation resins attributed its low decomposition ratio to formation of a highly heat-resistant polymer (sulfur bridged) during pyrolysis. Measurements of residual hygroscopicity and cement package strength indicated that the optimum pyrolysis temperatures for preventing resins swelling and package expansion were between 300 and 5000C.

1986-01-01

 
 
 
 
161

Decomposition of ion exchange resins by pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of spent ion exchange resins is one of the most effective methods for reducing radioactive waster volume and for making the final waste form more stable. Fundamental experiments were performed to clarify the pyrolysis characteristics of anion and cation exchange resins. Residual elemental analyses and off-gas analyses showed that the decomposition ratio of cation resins was only 50 wt% at 600/sup 0/C, while that of anion resins was 90 wt% at 400/sup 0/C. Infrared spectroscopy for cation resins attributed its low decomposition ratio to formation of a highly heat-resistant polymer (sulfur bridged) during pyrolysis. Measurements of residual hygroscopicity and cement package strength indicated that the optimum pyrolysis temperatures for preventing resins swelling and package expansion were between 300 and 500/sup 0/C.

Matsuda, M.; Funabashi, K.; Nishi, T.; Yusa, H.; Kikuchi, M.

1986-11-01

162

Kinetics of biomass pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The project Kinetics of Biomass Pyrolysis of the Department of Energy and Process Engineering at Tampere University of Technology (TUT) is focused on the modelling of the chemical kinetics and heat transfer effects of wood pyrolysis. The project focused especially on the effect of the internal heat transfer rate of the fuel particles and on the chemical reaction kinetics of the pyrolysis reactions. The project aimed to form a one dimensional mathematical simulation tool.

Kokko, L. [Tampere Univ. of Technology,Dept. of Energy and Process Engineering (Finland)], email: lauri.kokko@tut.fi

2012-07-01

163

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 600°C.

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

2009-01-01

164

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)

2010-01-01

165

Pyrolysis of an agricultural by-product: a characterization study  

Energy Technology Data Exchange (ETDEWEB)

Evolution of chemical and textural features characterizing shells of peanut (Arachis hypogaea) species subjected to three different pyrolysis temperatures is analyzed by several techniques. Surface areas of the raw material and pyrolyzed samples are evaluated from physical adsorption measurements employing N2 at 77 K and CO2 at 298 K. Results point to significant feature changes, which are, in general, strongly affected by pyrolysis conditions, and in particular by pyrolysis temperature. Furthermore, kinetic measurements of peanut shells pyrolysis are performed by non-isothermal thermogravimetric analysis, from ambient temperature up to 1123 K. A kinetic model reported in the literature, which takes into account the significant chemical and physical changes occurring within the residue in the course of the pyrolysis process, as evidenced from the results of chemical and textural characterization, was applied. This model properly describes actual kinetic data over the wide range of temperatures used. (author)

Cukierman, A.L.; Della Rocca, P.A.; Bonelli, P.R.; Cerrella, E.G. [University de Buenos Aires (Argentina)

1999-07-01

166

FAST PYROLYSIS OF ENZYMATIC/MILD ACIDOLYSIS LIGNIN FROM MOSO BAMBOO  

Directory of Open Access Journals (Sweden)

Full Text Available 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. Pyrolysis temperature had a distinct impact on yields of pyrolysis products. As pyrolysis temperature increased, the yield of 2,3-dihydrobenzofuran rapidly decreased; however, yields of phenols increased smoothly. It can be obtained that, at the low temperatures (250-400oC), pyrolysis products were mainly 2,3-dihydrobenzofuran, and the highest yield was 66.26% at 320oC; at the high temperatures (400-800oC), pyrolysis products were mainly phenols, and yields hit their highest level of 56.43% at 600 oC. A minor amount of acetic acid only emerged at 800°C. Knowledge of pyrolysis products releasing from EMAL and the pyrolysis mechanism could be basic and essential to the understanding of thermochemical conversion of EMAL to chemicals or high-grade energy.

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

2010-01-01

167

Effect of gamma ray irradiation on deoxygenation by hydrazine in artificial seawater  

International Nuclear Information System (INIS)

[en] At the spent nuclear fuel pools in the Fukushima Daiichi Nuclear Power Plant, hydrazine has been added to reduce dissolved oxygen in the pool water containing salts. The reduction behavior of dissolved oxygen in seawater with hydrazine in the presence of radiation is unknown. The effect of gamma ray irradiation on deoxygenation by hydrazine in artificial seawater was investigated at room temperature. We placed the artificial seawater with a small amount of hydrazine under gamma ray irradiation at dose rates of 0.3-7.5 kGy/h. The concentration of dissolved oxygen in the solutions was measured before and after the irradiation. The concentration of dissolved oxygen hardly decreased in the absence of gamma radiation in a few hours, whereas it markedly decreased in the presence of gamma radiation. The concentration of dissolved oxygen decreased with irradiation time. At this moment, hydrazine concentration decreased more than twice the dissolved oxygen concentration. This shows that some gamma radiolysis products of hydrazine act as deoxidizers. The concentration of dissolved oxygen in artificial seawater could be decreased by the addition of a small amount of hydrazine in the presence of gamma radiation at room temperature. (author)

2012-01-01

168

Energy source by pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Specific thermal values of organic, polymer and cardboard wastes; production of burnable gas by means of pyrolysis. Three examples in which the pyrolysis of production wastes is used for producing process and thermal heat: producing firm (probably plastics industry), firm producing hemp and sisal cordage, firm producing cigarette papers and sleeves.

1981-01-01

169

Relationship between initial moisture content and the liquid yield from pyrolysis of sawdust  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis of sawdust from beech wood results in the production of charcoal, liquid and gaseous products. The yields of liquid products increase with increasing pyrolysis temperature from 575 to 700 K, then decrease with increasing the temperature. The yield of oil increases with increasing the initial moisture content of the sample. The results indicated that the presence of moisture influenced significantly the thermal degradation rate of sawdust pyrolysis. The peak temperatures in pyrolysis were about 691 and 702 K for heating rates of 5 K/min. The liquid yield from pyrolysis of the sawdust with 54.8% moisture was about 33% higher than that in nitrogen stream. (Author)

Demirbas, A. [Selcuk Univ., Konya (Turkey). Dept. of Chemical Engineering

2005-07-15

170

Finding order in coal pyrolysis kinetics  

Energy Technology Data Exchange (ETDEWEB)

A number of experiments have suggested that the rate constants for the release of tar and for the thermal decomposition of the various functional groups in coal pyrolysis depend on the nature of the bridging bond or of the functional group, but appear relatively insensitive to coal rank for lignites, subbituminous and bituminous coals. The principal variation of pyrolysis behavior with rank is due to variations in the concentrations of functional groups and hence, the amount of each pyrolysis product. If the insensitivity of coal pyrolysis kinetics to coal rank can be generally demonstrated, it represents an important simplifying assumption in any general theory of coal pyrolysis. But the rank insensitivity of rate constants is controversial. There are two major questions. What species exhibit rank insensitive kinetics. Quantitatively, what does insensitivity mean, variations less than factors of two, ten, hundred etc.. This paper considers whether pyrolysis data in the literature support the hypothesis of rank insensitive kinetic rate constants. The experiments considered vary in duration from 1.4 msec to 12 hr and in temperature from 350/sup 0/c to 1800/sup 0/c.

Solomon, P.R.; Hamblen, D.G.

1983-01-01

171

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; Indarto Indarto; Harwin Saptoadi; Tri Agung Rohmat

2011-01-01

172

Pyrolysis of sawdust in a conical spouted-bed reactor with a HZSM-5 catalyst  

Energy Technology Data Exchange (ETDEWEB)

The effect was studied of using an in-situ catalyst based on a HZSM-5 zeolite in flash pyrolysis with an inert gas (N{sub 2}) of pinus insignis sawdust in a conical spouted-bed reactor in the 400--500 C range and for a gas residence time of 50 ms. The use of the catalyst increases the yield of gases and decreases the yields of liquid and char. Likewise, the yield of CO{sub 2} decreases, whereas the yield of C{sub 4{minus}} hydrocarbons increases (15.9 wt. % at 450 C). The catalyst is efficient for partial deoxygenation of the liquid product.

Olazar, M.; Aguado, R.; Bilbao, J.; Barona, A.

2000-05-01

173

Treatment of pyrolysis fuel oil  

Energy Technology Data Exchange (ETDEWEB)

A pyrolysis fuel oil (Black oil) is contacted with a promoter liquid having a 5 volume percent distillation temperature of at least 250/sup 0/F and a 95 volume percent distillation temperature of at least 350/sup 0/ F and no greater than about 75/sup 0/ , with the the liquid having a characterization factor of at least 9.75 to promote the separation of quinoline insolubles and asphaltenes from the fuel oil. A fraction free of quinoline insolubles and having a reduced content of asphaltenes may be subjected to coking to produce a needle coke, or employed directly for the production of carbon black.

Simone, A.A.

1980-06-10

174

Catalytic Deoxygenation of 1,2-Propanediol to Give n-Propanol  

Energy Technology Data Exchange (ETDEWEB)

Catalytic deoxygenation of 1,2-propanediol has been studied as a model the for deoxygenation of polyols and other biomass-derived compounds. Deoxygenation of 1,2-propanediol (1.0 M in sulfolane) catalyzed by {[Cp*Ru(CO)2]2(?-H)}+OTf – (0.5 mol %) at 110 °C under H2 (750 psi) in the presence of HOTf (60 mM) gives n-propanol (54 %) as the major product, indicating a high selectivity for deoxygenation of the internal OH over the terminal OH of the diol. Di-n propyl ether forms through condensation of n-propanol with itself, and propylene glycol propyl ether arises from condensation of n-propanol with the starting material diol, giving a total of up to 80 % yield for deoxygenation / hydrogenation products under these conditions. The deoxygenation of 1,2-propanediol is strongly influenced by the concentration of acid, giving faster rates and proceeding to higher conversions as the concentration of HOTf is increased. There is little or no dependence of the rate on the pressure of H2. Propionaldehyde was observed as an intermediate, being formed through acid-catalyzed dehydration of 1,2-propanediol. This aldehyde is hydrogenated to n-propanol through an ionic pathway involving protonation of the aldehyde, followed by hydride transfer from the neutral hydride, Cp*Ru(CO)2H. The proposed mechanism for the deoxygenation/hydrogenation reaction involves formation of a highly acidic dihydrogen complex, [Cp*Ru(CO)2(?2-H2)]+OTf-. Regeneration of the dihydrogen complex occurs through reaction of Cp*Ru(CO)2OTf with H2. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy.

Schlaf, Marcel; Ghosh, Prasenjit; Fagan, Paul J.; Hauptman, Elisabeth; Bullock, R. Morris

2009-03-01

175

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 ml·kg-1·min-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; Hajime Fujimoto; Hiroyuki Sugimori; Kei Miyamoto; Toshiki Tachi; Sachio Nagasaki; Yoshihiro Kato; Toshio Matsuoka

2008-01-01

176

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, Goiás, one of the main rivers of the state. Water samples were collected in the urban area of Goiânia, Goiânia New District 2, which shows apparent anthropogenic interference with the natural environment. After corrected to the standard temperature of 20°C, 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.

Suzi Mari Brandelero; Eduardo Queija de Siqueira; Ana Carolina de Brito Lima

2010-01-01

177

Pyrolysis of cellulose and lignin  

International Nuclear Information System (INIS)

[en] X-ray and UV-induced photoelectron spectroscopy (XPS and UPS) and scanning electron microscopy (SEM) have been performed to characterise the pyrolysis of cellulose and lignin and their interaction with methanol. Clean highly oriented pyrolitic graphite (HOPG) was also analysed as a reference material. Asymmetric C1s core level fits and valence band XPS of the samples indicate a graphitic-like structure after the pyrolysis at 1200 deg. C. Due to the low polar contents in pyrolysed cellulose and lignin, an interaction with methanol under high vacuum conditions could not be identified. From a technical viewpoint a temperature of 1200 deg. C is attainable without high costs. Therefore, the pyrolysis of wood-based polymers containing high amounts of cellulose and lignin are potential low-cost materials for various applications. If it is possible to generate graphite in complex structures made of wood-based polymers, a cheap and energy-efficient method will become available for producing bipolar plates for fuel cells. Technical problems like form instability and foaming are discussed as well as further development and possible modifications of the ground material to achieve optimal compositions.

2009-06-30

178

A thermodynamic model for pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The rate of pyrolysis of a coal depends on the nature of the coal and its components, in particular the macerals present. The authorsresearch programme is attempting to determine the thermal behaviour of liptinitic materials. As it is difficult to obtain large quantities of these materials by hand separation from coal the authors obtained maceral samples from other sources. In this work the thermal behaviour of lamalginitic material mainly derived from the planktonic algal genus Pediastrum is reported. The authors believe the results can be extended to modelling alginite in a range of coals of industrial significance in Australia. The thermal behaviour of the lamalginite was studied using thermogravimetry and modulated differential scanning calorimetry to measure the heat capacities and reaction enthalpies of the unique components separated from the lamalginite material and literature data for more common components. A thermodynamic database model of the pyrolysis was constructed from this data which allowed calculation of the overall pyrolysis enthalpy of the lamalginite material over a given temperature range for a given sample composition. 12 refs., 1 fig., 3 tabs.

Berkovich, A.J.; Young, B.R.; Levy, J.H.; Schmidt, S.J.; Wilson, M.A. [University of Technology, Sydney, NSW (Australia). Dept. of Chemistry, Materials and Forensic Science

1998-12-31

179

Low rank coals upgrading by mild pyrolysis technique  

Energy Technology Data Exchange (ETDEWEB)

Nowadays existing technologies of coal upgrading use two-stage process: coal drying and pyrolysis. One of these technologies is upgrading of low rank coals by mild pyrolysis known as LFC{trademark} process (means Liquids From Coal). Upgrading of low rank coals by LFC{trademark} process results to stable, high efficiency solid fuel names PDF{trademark} (Process-Derived Fuel). Up to 10--12% of liquids pyrolysis products names CDL{trademark} (Coal Derived Liquids) are available from this process. Apparently significant quantity of valuable chemicals such as phenols, cresols and hydrocarbons may be obtained by a simple processing of the pyrolysis tar. Is well known that water influenced on the yields and properties of pyrolysis products. The active role of water vapors in steam pyrolysis of brown coals, leading to strong modification of the adsorption properties of resulting solid carbons, could be observed at temperature between 500 and 600 C. In commercial scale the upgrading of coals by the steam pyrolysis may be accomplished by rapid pyrolysis of high moisture low-rank coals in one stage. New products of such coal upgrading may have a value properties. That is why the effect of water during mild pyrolysis of low rank coals was selected as the purpose of studying of this work.

Korobetskii, I.A.; Ismagilov, M.S.

1998-07-01

180

The use of waste matter after olive grove pruning for the preparation of charcoal. The influence of the type of matter, particle size and pyrolysis temperature  

Energy Technology Data Exchange (ETDEWEB)

Charcoal was obtained from waste matter after olive grove pruning: leaves, branch bark, twig and wood (sawdust and cubes of different sizes). The charcoals were prepared by pyrolysis under dynamic heating conditions in nitrogen (dynamic, 200ml/min) and air (static) and were characterized by proximate and elemental analysis, helium density and BET surface area. (author).

Valenzuela Calahorro, C.; Gomez Serrano, V.; Bernalte Garcia, A. (Univ. de Extremadura, Badajoz (ES). Dept. de Quimica Inorganica); Hernandez Alvaro, J. (Colegio Univ., Jaen (ES))

1992-01-01

 
 
 
 
181

Pyrolysis kinetics of acid-leached rice husk  

Energy Technology Data Exchange (ETDEWEB)

A highly pure mixture of carbon and silica was obtained on pyrolysis rice husk leached with acid at high temperature in a nonoxidizing atmosphere. The product was suitable for use as a starting material in the manufacture of silicon nitride powder. The effect of treatment including the kind and concentration of acid and the pyrolysis temperature on the constituents of the specimen was presented. Kinetic tests on pyrolysis of rice husk in a nitrogen atmosphere were carried out with a thermal gravimetric analysis (TGA) technique at heating rates 2, 3, and 5 K/min. The results indicated that thermal degradation of rice husk consisted of two distinct pyrolysis stages. The corresponding kinetic parameters including the activation energy were determined. A reasonable pyrolysis mechanism was proposed, which agreed satisfactorily with the experimental results.

Liou, T.H.; Chang, F.W.; Lo, J.J. [National Central Univ., Chungli (Taiwan, Province of China). Dept. of Chemical Engineering

1997-03-01

182

A pyrolysis mill for fast pyrolysis of biomass  

Energy Technology Data Exchange (ETDEWEB)

Conventional pyrolysis produces charcoal, pyrolysis oil and gas in approximately equal proportions. However fast pyrolysis has the potential for producing over 60% of an organic pyrolysis oil from biomass. The oil can be used as a low grade boiler fuel or the vapors can be converted to gasoline-like fuels. However, this requires high rates of heat a transfer. Heat transfer can be greatly enhanced by contact between biomass and hot solid surfaces. A pyrolysis mill has been developed to produce pyrolysis oil from biomass particles. Preliminary data from operation of the mill is presented.

Reed, B.; Cowdery, C.C. (Colorado School of Mines, Golden (USA))

1989-01-01

183

Acidification and Deoxygenation during Hyperthermal Events: Evidence from Seafloor Biota  

Science.gov (United States)

The Paleocene-Eocene Thermal Maximum and other early Eocene hyperthermals were short-lived (104-105 years) episodes of very warm climate, linked to emission of isotopically depleted carbon into the ocean-atmosphere system (~55-50 Ma). During these episodes there was severe dissolution of carbonate on the seafloor, and there is evidence of low oxygen conditions at least in parts of the world’s oceans. Benthic foraminifera suffered severe extinction during the most severe hyperthermal, the PETM. On Walvis Ridge (SE Atlantic), benthic foraminiferal assemblages were studied along a depth transect (1500-3600 m) across the PETM, Eocene Thermal Maximum 2 (ETM-2 or Elmo, ~ 1.8 myr after the PETM) and Eocene Thermal Maximum 3 (ETM-3 or X-event, ~ 3.1 myr after the PETM). During hyperthermals, benthic assemblages at all sites are characterized by low-diversity and dominance of relatively small and thin-walled specimens, and indicate a lower supply of food to the seafloor, possibly because of decreased open-ocean productivity during periods of warming. The severe dissolution associated with the PETM allowed no preservation of carbonate tests along the depth transect, but the dissolution interval reflected less time at the shallower sites. Benthic assemblages from above the dissolution interval indicate that Oxygen Minimum Zones expanded downwards over the shallower sites in the earlier and later stages of the main Carbon Isotope Excursion (CIE) associated with the PETM. Benthic foraminifera were present throughout the CIE associated with ETM-2 at the deepest site, but absent to very rare in a few samples from the shallowest site. Assemblages show a similar to, but less extreme pattern than that during the PETM, with development of low-oxygen conditions during the earliest and latest stages of the event. There is no evidence in the benthic assemblages from ETM-3 that OMZs expanded to the depth transect. It is not yet clear whether the combination of ocean acidification and deoxygenation caused the global extinction of deep-sea benthic foraminifera during the PETM, or whether warming itself and/or its effect on oceanic productivity were major factors. Benthic foraminiferal preservation and diversity across the PETM, Walvis Ridge Site 1263 (paleodepth 1500m).

Thomas, E.; Zachos, J. C.; Roehl, U.

2010-12-01

184

Application of hierarchical MFI zeolite for the catalytic pyrolysis of Japanese larch.  

UK PubMed Central (United Kingdom)

The catalytic pyrolysis of Japanese larch was carried out over a hierarchical MFI zeolite (Meso MFI C16). The zeolite was synthesized using an amphiphilic organosilane as a mesopore-directing agent, and its catalytic activity was compared with that of the conventional HZSM-5 and the mesoporous material from HZSM-5 (MMZ(ZSM-5)). The effect of the hierarchical MFI zeolite on the product distribution and chemical composition of the bio-oil was also examined. The hierarchical MFI zeolite exhibited the highest activity in deoxygenation and aromatization during the catalytic pyrolysis of Japanese larch. In particular, it showed high selectivity for valuable aromatics, such as benzene, toluene, and xylenes (BTX), even though it decreased the organic fraction of bio-oil. Its higher mesoporosity resulted, however, in an increase in the coke amount and in undesirable products, such as polycyclic aromatic hydrocarbons (PAHs).

Park KH; Park HJ; Kim J; Ryoo R; Jeon JK; Park J; Park YK

2010-01-01

185

Application of hierarchical MFI zeolite for the catalytic pyrolysis of Japanese larch.  

Science.gov (United States)

The catalytic pyrolysis of Japanese larch was carried out over a hierarchical MFI zeolite (Meso MFI C16). The zeolite was synthesized using an amphiphilic organosilane as a mesopore-directing agent, and its catalytic activity was compared with that of the conventional HZSM-5 and the mesoporous material from HZSM-5 (MMZ(ZSM-5)). The effect of the hierarchical MFI zeolite on the product distribution and chemical composition of the bio-oil was also examined. The hierarchical MFI zeolite exhibited the highest activity in deoxygenation and aromatization during the catalytic pyrolysis of Japanese larch. In particular, it showed high selectivity for valuable aromatics, such as benzene, toluene, and xylenes (BTX), even though it decreased the organic fraction of bio-oil. Its higher mesoporosity resulted, however, in an increase in the coke amount and in undesirable products, such as polycyclic aromatic hydrocarbons (PAHs). PMID:20352861

Park, Kyu-Hong; Park, Hyun Ju; Kim, Jeongnam; Ryoo, Ryong; Jeon, Jong-Ki; Park, Junhong; Park, Young-Kwon

2010-01-01

186

The characteristic and evaluation method of fast pyrolysis of microalgae to produce syngas.  

UK PubMed Central (United Kingdom)

The fast pyrolysis of Chlorella vulgaris was carried out in a quartz tube reactor under different pyrolysis temperature levels. The product fractional yields, gaseous products and the evaluation method based on heating value and energy consumption were analyzed in order to obtain the optimal condition to produce syngas. The results indicated that the higher the pyrolysis temperature level was, the higher the bio-fuel yield was. 900°C is the best temperature to obtain the maximum bio-fuel yield (91.09 wt.%). And the highest emission of CO and H2 were achieved under the pyrolysis temperature of 800 and 900°C, respectively. According to the evaluation method based on heating value and energy consumption, there was a significant impact on the syngas production under different pyrolysis temperatures. Furthermore, the evaluation method based on energy consumption indicated that 800°C was the optimal pyrolysis temperature to produce syngas.

Hu Z; Ma X; Li L

2013-07-01

187

The characteristic and evaluation method of fast pyrolysis of microalgae to produce syngas.  

Science.gov (United States)

The fast pyrolysis of Chlorella vulgaris was carried out in a quartz tube reactor under different pyrolysis temperature levels. The product fractional yields, gaseous products and the evaluation method based on heating value and energy consumption were analyzed in order to obtain the optimal condition to produce syngas. The results indicated that the higher the pyrolysis temperature level was, the higher the bio-fuel yield was. 900°C is the best temperature to obtain the maximum bio-fuel yield (91.09 wt.%). And the highest emission of CO and H2 were achieved under the pyrolysis temperature of 800 and 900°C, respectively. According to the evaluation method based on heating value and energy consumption, there was a significant impact on the syngas production under different pyrolysis temperatures. Furthermore, the evaluation method based on energy consumption indicated that 800°C was the optimal pyrolysis temperature to produce syngas. PMID:23693148

Hu, Zhifeng; Ma, Xiaoqian; Li, Longjun

2013-05-03

188

Biomethanation of biomass pyrolysis gases  

Science.gov (United States)

The development of the biological methanation process and conditions for maximum performane were studied. Gasification processes have the potential to produce a synthesis gas from biomass. The advantage of such processes is that all organic components of the biomass may be converted to synthesis gas. However, this low Btu value gas is of limited use as a fuel gas. To convert the synthesis gas into pipeline quality methane, a methanation process is necessary. A more economical alternative to catalytic methanation at high temperature and pressure is the utilization of a biological system to carry out the conversion of biomass pyrolysis gases to methane.

Tracy, C. A.; Ashare, E.

1981-08-01

189

Relationship between hydrous and ordinary pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis results are reviewed briefly with the intent of drawing comparisons between open, high pressure, and hydrous pyrolysis. Empirically, the degree of pyrolysis severity to form volatile products in open pyrolysis is similar to that required to form an expelled oil phase in hydrous pyrolysis. The yields of hydrocarbons from open pyrolysis are close to those from hydrous pyrolysis, but hydrous pyrolysis tends to assist the separation of hydrocarbons from polar materials. Pressure has a small but measurable affect on the generation kinetics.

Burnham, A.K.

1993-06-01

190

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

2013-06-02

191

Pyrolysis of waste tyres: a review.  

UK PubMed Central (United Kingdom)

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.

Williams PT

2013-08-01

192

Pyrolysis of Pine Wood : Experiments and Theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, pinewood has been pyrolyzed using a fixed heating rate with a variable end-temperature. The pyrolysis process has been simulated using a mechanism with three parallel reactions for the formation of char, gas and tar. First order irreversible kinetics is assumed. This kind of model may...

Fjellerup, Jan Søren; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk

193

Effects of pyrolysis temperature, time and leaf litter and powder coal ash addition on sludge-derived adsorbents for nitrogen oxide.  

UK PubMed Central (United Kingdom)

The objective of this research was to seek a cost effective solution to prepare adsorbents for nitrogen oxide from surplus sludge. Leaf litter and powder coal ash were used as cheap and easily available additives. An adsorbent for nitrogen oxide was prepared by pyrolysis of dried sludge mixed with zinc chloride. Under optimum pyrolysis conditions of 375°C for 90 min and a zinc chloride content of 30%, the surface area of the adsorbent with leaf litter was 514.41 m(2)/g, the surface area of the adsorbent with powder coal ash was 432.34 m(2)/g, respectively, corresponding to an increase of 90.70% and 60.27% when compared to the adsorbent without the additives. The saturated adsorption quantity of the adsorbent with leaf litter reached 271 mg/g at 20°C. The results indicated that the sludge-derived adsorbent was quite promising for nitrogen oxide removal.

Ren X; Liang B; Liu M; Xu X; Cui M

2012-12-01

194

Pyrolysis and Oxidation of PAN in Dry Air. Thermoanalytical Methods  

Directory of Open Access Journals (Sweden)

Full Text Available The results of investigations on pyrolysis and oxidation of pure polyacrylonitrile (PAN) and its mixture with N,N-dimethylformamide (DMF) under non-isothermal conditions at linear change of samples temperature in time are presented. In each case process proceeded in different way. During pyrolysis of pure PAN the material containing mainly the product after PAN cyclization was obtained, while pyrolysis of PAN+DMF mixture gave the product after cyclization and stabilization. Under conditions of measurements, in both temperature ranges, series of gaseous products were formed.

Anna BIEDUNKIEWICZ; Pawel FIGIEL; Marta SABARA

2011-01-01

195

Pyrolysis of scrap tyres with zeolite USY.  

Science.gov (United States)

A zeolite catalyst of ultrastable Y-type (USY) was investigated in the research of two staged pyrolysis-catalysis of scrap tyres. Scrap tyres were pyrolysed in a fixed bed reactor and the evolved pyrolysis gases were passed through a secondary catalytic reactor. The main objective of this paper was to investigate the effect of zeolite USY on the yield of products and the composition of derived oil. The influences of several parameters such as pyrolysis temperature, catalytic temperature, catalyst/tyre ratio, heating rate, etc. on the yield of the derived oil, char and gas were investigated. It showed that the increase of catalytic temperature and catalyst/tyre ratio resulted in high yield of gas at the expense of the oil yield. For example, when the catalyst/tyre ratio increased from 0.25 to 1.0, the yield of gas increased from 30.5 to 49.9 wt.%, and the oil yield decreased nearly two-fold from 31.6 to 12.7 wt.%. The concentration of light naphtha (boiling point < 160 degrees C) was also investigated in this study. And the high catalyst/tyre ratio favored to increase the concentration of light naphtha (< 160 degrees C) in oil. In order to study the composition of derived oil, a distilled fraction (< 280 degrees C), which was 92.5 wt.% of the oil obtained from catalytic pyrolysis of scrap tyre at a pyrolysis temperature, catalytic temperature and catalyst/tyre ratio of 500, 400 degrees C and 0.5, respectively, was analyzed with gas chromatography/mass spectrometry (GC/MS). The distillate was found to contain 1.23 wt.% benzene, 9.35 wt.% toluene, 3.68 wt.% ethylbenzene, 12.64 wt.% xylenes, 1.81 wt.% limonene and 13.89 wt.% PAHs, etc., where the single ring aromatics represented a significant potential use as chemicals. PMID:16704900

Shen, Boxiong; Wu, Chunfei; Wang, Rui; Guo, Binbin; Liang, Cai

2006-03-29

196

Tissue deoxygenation kinetics induced by prolonged hypoxic exposure in healthy humans at rest.  

Science.gov (United States)

ABSTRACT. This study aimed to investigate the effects of sustained hypoxic exposure on cerebral and muscle oxygenation and cardiorespiratory function at rest. Eleven healthy subjects inhaled a normobaric hypoxic (FiO2=0.12) or normoxic (FiO2=0.21) gas mixture for 4 h at rest, on two separated blinded sessions. Arterial oxygen saturation (SpO2), heart rate variability (HRV), end-tidal CO2 (EtCO2), and oxygenation of quadriceps muscle, prefrontal and motor cortices assessed by near-infrared spectroscopy (NIRS) were measured continuously during each session. Acute mountain sickness symptoms were evaluated at the end of each session. During a hypoxic session, SpO2 reduction (?13%) plateaued after 20 min, while deoxygenation pattern took 30 to 40 min at the cerebral sites to plateau (+5.3±1.6???Mol of deoxygenated-hemoglobin). Deoxygenation was more pronounced in the cerebral cortex compared to the muscle (+2.1±2.3???Mol of deoxygenated-hemoglobin), and NIRS-derived tissue perfusion index showed distinct profiles between the muscle (hypoperfusion) and the brain (hyperperfusion) with prolonged hypoxia. Changes in tissue oxygenation were not associated with cardiorespiratory responses (e.g., HRV, EtCO2) and altitude sickness symptom appearance during hypoxic sessions. These data demonstrate that sustained hypoxia elicits time delay in changes between arterial and tissue (especially cerebral) oxygenation, as well as a tissue-specific sensitivity. PMID:24064948

Rupp, Thomas; Leti, Thomas; Jubeau, Marc; Millet, Guillaume Y; Bricout, Veronique A; Levy, Patrick; Wuyam, Bernard; Perrey, Stephane; Verges, Samuel

2013-09-01

197

Tissue deoxygenation kinetics induced by prolonged hypoxic exposure in healthy humans at rest.  

UK PubMed Central (United Kingdom)

ABSTRACT. This study aimed to investigate the effects of sustained hypoxic exposure on cerebral and muscle oxygenation and cardiorespiratory function at rest. Eleven healthy subjects inhaled a normobaric hypoxic (FiO2=0.12) or normoxic (FiO2=0.21) gas mixture for 4 h at rest, on two separated blinded sessions. Arterial oxygen saturation (SpO2), heart rate variability (HRV), end-tidal CO2 (EtCO2), and oxygenation of quadriceps muscle, prefrontal and motor cortices assessed by near-infrared spectroscopy (NIRS) were measured continuously during each session. Acute mountain sickness symptoms were evaluated at the end of each session. During a hypoxic session, SpO2 reduction (?13%) plateaued after 20 min, while deoxygenation pattern took 30 to 40 min at the cerebral sites to plateau (+5.3±1.6???Mol of deoxygenated-hemoglobin). Deoxygenation was more pronounced in the cerebral cortex compared to the muscle (+2.1±2.3???Mol of deoxygenated-hemoglobin), and NIRS-derived tissue perfusion index showed distinct profiles between the muscle (hypoperfusion) and the brain (hyperperfusion) with prolonged hypoxia. Changes in tissue oxygenation were not associated with cardiorespiratory responses (e.g., HRV, EtCO2) and altitude sickness symptom appearance during hypoxic sessions. These data demonstrate that sustained hypoxia elicits time delay in changes between arterial and tissue (especially cerebral) oxygenation, as well as a tissue-specific sensitivity.

Rupp T; Leti T; Jubeau M; Millet GY; Bricout VA; Levy P; Wuyam B; Perrey S; Verges S

2013-09-01

198

Effects of disodium cromoglycate on cationic exchange of deoxygenated sickle cells.  

UK PubMed Central (United Kingdom)

In the present work, we explored the way in which cromoglycate, a drug used to treat allergies acts on ion movements in sickle cells. Cells were either slowly deoxygenated by overnight exposure to nitrogen or acutely deoxygenated by exposure to metabisulfite, a strong reducing agent which induces sickling of red blood sickle cells. Flushing the cells with nitrogen increased the intracellular concentration of Na(+) and decreased the intracellular concentration of K(+) and the sum of the concentrations of the two cations. One hundred nM cromoglycate inhibited the decrease of intracellular K(+) and the increase of intracellular Na(+) induced by deoxygenation (n=17). Metabisulfite (100mM) increased the intracellular concentration of Ca(2+) (measured by Fura Red) (n=15) and the shape of the cells (measured by light scattering) (n=9). One ?M cromoglycate partially inhibited these two responses. In conclusion, cromoglycate partially inhibits abnormal K(+) loss, Ca(2+) entry pathways or Ca(2+) channels opened by cell deoxygenation and ensuing membrane modifications and prevents cell sickling.

Bizumukama L; Ferster A; Gulbis B; Kumps A; Cotton F

2011-08-01

199

CATALYTIC THERMAL DECOMPOSITION OF POLYETHYLENE BY PYROLYSIS GAS CHROMATOGRAPHY  

Directory of Open Access Journals (Sweden)

Full Text Available An experimental study of the thermal decomposition of polyethylene in an inert atmosphere has been carried out in the temperature range 300-800°C 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 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

2011-01-01

200

Finding order in coal pyrolysis kinetics  

Energy Technology Data Exchange (ETDEWEB)

A number of experiments have suggested that the rate constants for the release of tar and for the thermal decomposition of the various functional groups in coal pyrolysis depend on the nature of the bridging bond or of the functional group, but appears relatively insensitive to coal rank for lignites, subbituminous and bituminous coals. The principal variation of pyrolysis behavior with rank is due to variations in the concentrations of functional groups and hence, the amount of each pyrolysis product. If the insensitivity of coal pyrolysis kinetics to coal rank can be generally demonstrated, it represents an important simplifying assumption in any general theory of coal pyrolysis. But the rank insensitivity of rate constants is controversial. There are two major questions. What species exhibit rank insensitive kinetics. Quantitatively, what does insensitivity mean, variations less than factors of two, ten, hundred, etc. This paper considers whether pyrolysis data in the literature support the hypothesis of rank insensitive kinetic rate constants. The experiments considered vary duration from 1.4 millisecond to 12 hours and in temperature from 350/sup 0/C to 1800/sup 0/C. Considering the available data, it appears that the decomposition of aliphatic and methyl functional groups, the loss of aromatic hydrogen and the evolution of tar and hydrocarbon species have rates which are relatively insensitive to rank variation. The rate varies by at most a factor of 5 between lignite and bituminous coals. Oxygen species are somewhat more rank sensitive. The factor of 5 variation in rate due to coal rank is substantially less than the factors of 100 to 10,000 in varition typical of reported rates. 56 references, 49 figures, 4 table.

Solomon, P.R.; Hamblen, D.G.

1983-09-01

 
 
 
 
201

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

202

Use of pyrolysis gas as reburn fuel  

Energy Technology Data Exchange (ETDEWEB)

To lower NO{sub x} emissions the process `Fuel Splitting and Staging` is investigated in a test facility at the University of Stuttgart. Raw coal is introduced into an electrically heated entrained flow reactor where it is split into pyrolysis gas and residual char. In the following staged combustion, the remaining char is used as primary fuel and the pyrolysis gas as reburn fuel. The test facility allows a systematic study in order to evaluate the effect of different parameters on NO{sub x}-reduction independently. The quantity and quality of the char and the pyrolysis gas are dependent on coal type, temperature, residence time and carrier gas composition. In particular, the latter parameter and the related tar yield were shown to be of special interest with regard to the reburn efficiency. With gaseous reburn fuels, minimum NO{sub x}-emissions below 100 ppm at 6% O{sub 2} could be achieved. The main parameters are the stoichiometry and the residence time in the secondary fuel rich zone. The results also show an increase in the reduction efficiency with increasing temperature. The tar and fuel-N concentration of a pyrolysis gas produced appear to have a positive effect on reducing the NO{sub x} emissions. 3 refs., 14 figs., 3 tabs.

Greul, U.; Ruediger, H.; Spliethoff, H.; Hein, K.R.G. [Universitaet Stuttgart, Stuttgart (Germany). Inst. fuer Verfahrenstechnik und Dampfkesselwesen

1995-12-31

203

Fast pyrolysis of biomass in free-fall reactor for hydrogen-rich gas  

Energy Technology Data Exchange (ETDEWEB)

Fast pyrolysis of two typical biomasses (legume straw and apricot stone) in a free-fall reactor was studied. The pyrolysis behavior of the biomass is strongly relevant to its chemical composition. Under fast heating and pyrolysis conditions as in the free-fall reactor, an interaction of the biomass pyrolysis with the in situ steam reforming of the pyrolysis intermediate products occurs, which leads to more hydrogen-rich gas yield. The total ratio of CO and H{sub 2} in the gas product reaches 65.4 mol% for legume straw and 55.7 mol% for apricot stone, respectively. Effects of sample particle size and pyrolysis temperature on the fast pyrolysis of the biomass were also studied.

Li, Shiguang; Xu, Shaoping; Liu, Shuqin; Yang, Chen; Lu, Qinghua [Institute of Coal Chemical Engineering, Chemical School of Dalian University of Technology, 158 Zhongshan Road, PO Box 33, Dalian, LiaoNing, 116012 (China)

2004-07-15

204

Residua pyrolysis and coke formation  

Energy Technology Data Exchange (ETDEWEB)

This study focused on the changes occurring in petroleum residua during the pyrolysis. To keep the overall system free energy at a minimum, it appears that asphaltenes self-adjust their apparent molecular weights to match the polarity of the solvent phase as closely as possible. The solubility parameters of the maltenes and asphaltenes increase, and the apparent molecular weight of the asphaltenes decreases as the thermal treatment progresses. The depletion of the intermediate polarity resins material reduces the ability of the asphaltenes to remain dispersed in the system, resulting in an unstable system. When this situation happens, the formation of a multi-phase system occurs, followed by coking. Two new Coking Indexes wee developed, on the basis of the asphaltene flocculation titration and the cyclohexane soluble portion of heptane asphaltenes. The p{sub a} divided by C{sub min} ratio based on Heithaus titration data is the first. The measurement of the weight percent cyclohexane solubles in heptane asphaltenes divided by the weight percent of heptane asphaltenes defines the second. The determination of these Indexes was effected for a wide array of residua materials undergoing pyrolysis. Regardless of the source of the material, the Coking Indexes seem to apply universally for residua. The nearness of a system to coke formation during the coke formation induction period is indicated by the Coking Indexes. The development of predictors for pyrolytic coke formation was performed using the dispersed particle solution model of petroleum residua structure. During the pyrolysis, the amount of coke initially formed seems to be a function of the free solvent volume of the original residuum. The three-dimensional coke make predictability maps at 400 degrees Celsius, 450 degrees Celsius and 500 degrees Celsius was developed using this relationship. Residence time and free solvent volume are related to the amount of coke formed at a particular pyrolysis temperature. At completion, the amount of coke formed is a function of the atomic hydrogen divided by carbon ratio. New tools for ranking residua, gauging proximity to coke formation, and the predicting of initial coke make tendencies resulted from this work. tabs., 78 figs.

Schabron, J.F. [Western Research Institute, Laramie, WY (United States)

2001-07-01

205

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

Energy Technology Data Exchange (ETDEWEB)

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

206

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

Energy Technology Data Exchange (ETDEWEB)

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 m{sup 3}/h and 350 to 550 C. The maximum oil yield of 64.25 wt% was obtained at a nitrogen gas flow rate of 1.75 m{sup 3}/h, particle size of 0.7-1.0 mm and pyrolysis temperature of 500 C. The calorific value of pyrolysis oil was found to be 19.66 MJ/kg. The pyrolysis gas can be used as a gaseous fuel. (author)

Raja, S. Antony; Kennedy, Z. Robert; Pillai, B.C.; Lee, C. Lindon Robert [School of Mechanical Sciences, Karunya University, Coimbatore, Tamil Nadu 641114 (India)

2010-07-15

207

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

International Nuclear Information System (INIS)

[en] 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.

2011-06-01

208

Reactions of oxygen containing structures in coal pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

In coal pyrolysis O-containing structures such as ether bridges and phenolic groups play an important role. Their reactions were studied by non-isothermal pyrolysis of a high volatile bituminous coal and some model polymers with gas chromatographic detection of the gaseous pyrolysis products. The coal was separated into the maceral groups vitrinite, exinite and inertinite, which showed markedly different pyrolysis behaviour. The formation of CO, methane and benzene was measured versus temperature. By comparison with polyphenyleneoxide and phenol-formaldehyde resins, it was found that the main volatilization, during which most of the tar is evolved, is initiated by cleavage of alkyl-aryl-ethers. Rearrangements of the primarily formed radicals lead to the formation of CO and methane at higher temperatures. 5 refs., 8 figs., 1 tab.

Hodek, W.; Kirschstein, J.; Van Heek, K.-H. (DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany, F.R.))

1991-03-01

209

Flash pyrolysis kinetics of pine wood  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of sawdust pyrolysis in the temperature range from 300 to 600[degree]C has been measured. A thermogravimetric analyser was applied for the temperature range from 300 to 450[degree]C while for measurements in the temperature range from 450 to 600[degree]C, an entrained flow reactor has been used. The kinetic expression that describes the mass loss of sawdust due to pyrolysis is assumed to be of a single first-order in the unconverted wood. The first-order rate constant obtained from measurement in both the thermogravimetric analyser and the entrained flow reactor can be described by an Arrhenius equation with k[sub O] 1.4 10[sup 10]kg.kg[sup -1].S[sup -1] and E[sub a] 150 KJ.mol[sup -1]. 4 refs., 5 figs.

Wagenaar, B.M.; Prins, W.; Swaaij, W.P.M. van (University of Twente, Enschede (Netherlands))

1993-12-01

210

Chicken manure pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The Advanced Biorefinery Inc. (ABRI) has been developing pyrolysis systems since 1988. This presentation provided details of the the 50-100 TPD model developed by the company, which uses pyrolysis to refine biomass fuels. Pyrolysis is the chemical change caused by heat in an oxygen-reduced or oxygen-free environment. Pyrolysis can be used to shatter biomass polymers to liquid, char or ash, or a medium BTU combustible gas. There are 3 liquid phases in pyrolysis: light aqueous; heavy 1 cyclic compounds; and heavy 2 aliphatics. With the 50-100 TPD model, part of the char is combusted to provide heat for drying and for reactions, and the remainder is used as a soil conditioner. Syngas is used to provide additional heat for electricity generation. The model is a centralized plant where manure is transported off the farm to a complex. Manure is processed into the highest value added products and residuals are returned to the farm for energy purposes. Advantages of the system include the fact that it is not capital intensive; provides on-site nutrient management; possible mortality disposal; pathogen containment, and energy self-sufficiency. The use of a central plant offers better economics and is more efficient for chemical separation. The payback period is estimated at under 5 years, with an estimated capital cost of $100,000. A monthly natural gas and electricity price forecast was presented. It was concluded that that the model may provide significant benefits to the environment, as nutrients are concentrated in char/ash and can be economically transported out of high intensity farming regions. Studies have suggested that the carbon content in char may also enhance soils and promote growth. refs., tabs., figs.

Fransham, P. [Advanced Biorefinery Inc., Ottawa, ON (Canada); Montreal, C. [Agriculture and Agri-Food Canada, Ottawa, ON (Canada). Strategic Policy Branch

2006-07-01

211

Thiophenic Sulfur Compounds Released During Coal Pyrolysis.  

UK PubMed Central (United Kingdom)

Thiophenic sulfur compounds are released during coal gasification, carbonization, and combustion. Previous studies indicate that thiophenic sulfur compounds degrade very slowly in the environment, and are more carcinogenic than polycyclic aromatic hydrocarbons and nitrogenous compounds. Therefore, it is very important to study the principle of thiophenic sulfur compounds during coal conversion, in order to control their emission and promote clean coal utilization. To realize this goal and understand the formation mechanism of thiophenic sulfur compounds, this study focused on the release behavior of thiophenic sulfur compounds during coal pyrolysis, which is an important phase for all coal thermal conversion processes. The pyrolyzer (CDS-5250) and gas chromatography-mass spectrometry (Focus GC-DSQII) were used to analyze thiophenic sulfur compounds in situ. Several coals with different coal ranks and sulfur contents were chosen as experimental samples, and thiophenic sulfur compounds of the gas produced during pyrolysis under different temperatures and heating rates were investigated. Levels of benzothiophene and dibenzothiophene were obtained during pyrolysis at temperatures ranging from 200°C to 1300°C, and heating rates ranging from 6°C/ms to 14°C/ms and 6°C/s to 14°C/s. Moreover, the relationship between the total amount of benzothiophene and dibenzothiophene released during coal pyrolysis and the organic sulfur content in coal was also discussed. This study is beneficial for understanding the formation and control of thiophenic sulfur compounds, since it provides a series of significant results that show the impact that operation conditions and organic sulfur content in coal have on the amount and species of thiophenic sulfur compounds produced during coal pyrolysis.

Xing M; Kong J; Dong J; Jiao H; Li F

2013-06-01

212

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

213

Production of n-alkanes and polycyclic aromatic hydrocarbons in coal pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The aim of the work reported was to follow some specific organic products of devolatilization and/or pyrolysis of different coals. Pyrolysis in combination with gas chromatographic separation and mass spectrometry detection is a useful technique for following the compounds which are produced in coal pyrolysis. Two families of compounds, linear hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were followed with a single-ion monitored program in order to enhance the detection limit of the method. A complete study of these two families of compounds and the pyrolysis temperature was carried out. Some conclusions were obtained about production at different temperatures by making comparisons between the experiments.

Bonfanti, L.; Comellas, L.; Lliberia, J.L.; Vallhonrat-Matalonga, R.; Pich-Santacana, M.; Lopez-Pinol, D. [ENEL Spa - CRT, Pisa (Italy). Centro di Ricerca Termica

1997-11-01

214

Distribution of nitrogen and sulfur in gaseous and liquid products from coal pyrolysis and hydropyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The results show that the behaviour of the heteroatoms is influenced by the different pyrolysis parameters. For the technical application the possibility to control the distribution of the heteroatoms of the pyrolysis products can be answered. The nitrogen distribution is less affected than the sulfur distribution by pyrolysis, especially at low temperature. Consequently the nitrogen release needs higher temperatures. The sulfur release during pyrolysis can be increased by hydrogen atmosphere, especially at high pressure, whereas an inert gas atmosphere has an opposite effect. 3 refs., 6 figs., 1 tab.

Wanzl, W.; Jahns, P.; Van Heek, K.H. (Bergbau-Forschung GmbH, Essen (Germany, F.R.))

1989-10-01

215

PYROLYSIS LIQUID DERIVED FROM OIL PALM EMPTY FRUIT BUNCHES  

Directory of Open Access Journals (Sweden)

Full Text Available Oil palm waste especially empty fruit bunches (EFB) is a major management and disposal problem in Malaysia. This is an exploratory evaluation of the potential for recovering renewable fuels from the EFB via fast pyrolysis. Preliminary studies were done on the characteristics of the empty fruit bunches, and the thermal behaviours using thermogravimetric analysis (TGA) were included as well. For the fast pyrolysis experimentation, a 150 g/h fluidized bed bench scale unit was used to study the effect of reaction temperature and vapour residence time on the pyrolysis products. Reaction temperatures studied were from 400 to 600ºC. It was found that the maximum organics liquid yield was at a reactor temperature of 450ºC. In all cases the pyrolysis liquid separated into two phases: an aqueous and a tarry phase. The pyrolysis liquid was analyzed by Fourier Transform Infrared (FTIR) spectroscopy. From the FTIR analysis, it was found that the pyrolysis liquid derived from empty EFB consisted mostly of hydrocarbon compounds.

N. Abdullah; A.V. Bridgwater

2006-01-01

216

Pyrolysis of waste plastic crusts of televisions.  

UK PubMed Central (United Kingdom)

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.

Liu X; Wang Z; Xu D; Guo Q

2012-09-01

217

Coal pyrolysis in a rotary kiln: Part 1. Model of the pyrolysis of a single grain  

Energy Technology Data Exchange (ETDEWEB)

A mathematical model is presented which describes the pyrolysis of a single grain of coal and is designed to be incorporated into an overall model simulating the rotary kiln coal pyrolysis process. The grain model takes into account the principal physical phenomena occurring during the conversion of coal to coke, namely, heat transfer toward and within the grain, drying of the coal, and the evolution of volatile species. Particular care has been taken in the determination of the thermophysical and kinetic parameters necessary for the model. Thus, the drying kinetics for Lorraine coal were measured by thermogravimetry. The kinetics of pyrolysis were determined by both thermogravimetry and gas-phase chromatography, in order to separately monitor the evolution of the nine gaseous species considered. The true specific heat and the thermal conductivity of the solid were also measured as a function of temperature. The numerical model, based on the finite-volume method, calculates the temperature, composition, and mass flow rates for the different gases evolved at each point in the grain at any instant of time. The model was, finally, validated by comparing the calculated and measured values of the overall conversion of the pyrolysis reaction and the temperature at the center of the grain.

Patisson, F.; Lebas, E.; Hanrot, F.; Ablitzer, D.; Houzelot, J.L.

2000-04-01

218

Gold Nanoparticle-Catalyzed Environmentally Benign Deoxygenation of Epoxides to Alkenes  

Directory of Open Access Journals (Sweden)

Full Text Available We have developed a highly efficient and green catalytic deoxygenation of epoxides to alkenes using gold nanoparticles (NPs) supported on hydrotalcite [HT: Mg6Al2CO3(OH)16] (Au/HT) with alcohols, CO/H2O or H2 as the reducing reagent. Various epoxides were selectively converted to the corresponding alkenes. Among the novel metal NPs on HT, Au/HT was found to exhibit outstanding catalytic activity for the deoxygenation reaction. Moreover, Au/HT can be separated from the reaction mixture and reused with retention of its catalytic activity and selectivity. The high catalytic performance of Au/HT was attributed to the selective formation of Au-hydride species by the cooperative effect between Au NPs and HT.

Akifumi Noujima; Takato Mitsudome; Tomoo Mizugaki; Koichiro Jitsukawa; Kiyotomi Kaneda

2011-01-01

219

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

UK PubMed Central (United Kingdom)

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.

Gurale BP; Vanka K; Shashidhar MS

2012-04-01

220

Experimental and numerical study of biomass flash pyrolysis in an entrained flow reactor.  

UK PubMed Central (United Kingdom)

Experiments on flash pyrolysis of biomass (rice husk and sawdust) were performed in an entrained flow reactor at different temperatures (700-1000 degrees C). Results show that temperature has great impact on the biomass flash pyrolysis reactions. With the increase of temperature, the gas yield increased, while the yields of char and liquid decreased. After the early stage of pyrolysis, the gas yield increased gradually which could be attributed to the increase of CO and CH(4) yields at low temperature, while to the increase of CO and H(2) yields at high temperature. A first order kinetic model was employed to describe biomass flash pyrolysis characteristics and the relevant kinetic parameters were determined. Numerical simulation of pyrolysis process was carried out, the predicted yields of produced gases agreed reasonably with the experimental data.

Sun S; Tian H; Zhao Y; Sun R; Zhou H

2010-05-01

 
 
 
 
221

Deoxygenation of Mono-oxo Bis(dithiolene) Mo and W Complexes by Protonation.  

UK PubMed Central (United Kingdom)

Protonation-assisted deoxygenation of a mono-oxo molybdenum center has been observed in many oxotransferases when the enzyme removes an oxo group to regenerate a substrate binding site. Such a reaction is reported here with discrete synthetic mono-oxo bis(dithiolene) molybdenum and tungsten complexes, the chemistry of which had been rarely studied because of the instability of the resulting deoxygenated products. An addition of tosylic acid to an acetonitrile solution of [Mo(IV)O(S2C2Ph2)2](2-) (1) and [W(IV)O(S2C2Ph2)2](2-) (2) results in the loss of oxide with a concomitant formation of novel deoxygenated complexes, [M(MeCN)2(S2C2Ph2)2] (M = Mo (3), W (4)), that have been isolated and characterized. Whereas protonation of 1 exclusively produces 3, two different reaction products can be generated from 2; an oxidized product, [WO(S2C2Ph2)2](-), is produced with 1 equiv of acid while a deoxygenated product, [W(MeCN)2(S2C2Ph2)2] (4), is generated with an excess amount of proton. Alternatively, complexes 3 and 4 can be obtained from photolysis of [Mo(CO)2(S2C2Ph2)2] (5) and [W(CO)2(S2C2Ph2)2] (6) in acetonitrile. A di- and a monosubstituted adducts of 3, [Mo(CO)2(S2C2Ph2)2] (5) and [Mo(PPh3)(MeCN)(S2C2Ph2)2] (7) are also reported.

Seo J; Williard PG; Kim E

2013-08-01

222

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

223

Pyrolysis process and apparatus  

Energy Technology Data Exchange (ETDEWEB)

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

224

Formation of HCN during pyrolysis of Pingshuo macerals  

Energy Technology Data Exchange (ETDEWEB)

Three macerals (liptinite, vitrinite and inertinite) which were separated from Pingshuo coal were used in this study. The formation of HCN during macerals pyrolysis was investigated using a quartz tube reactor at 600{degree}C to 900{degree}C. Both the programmed heating and fast heating pyrolysis had been studied. It was found that the yield of HCN increased with pyrolysis temperature for all three macerals. The yield of HCN during vitrinite pyrolysis was the highest among the three below 800{degree}C, and that of liptinite was the highest at 900{degree}C. The yields of HCN depended not only on their volatile content but also on the nitrogen functional groups in different macerals. More pyrrole-type nitrogen could form more HCN at lower temperature. The yield of HCN increased with increasing heating rate. Comparing the HCN yield at different periods during pyrolysis, it could be found that most of the HCN was released at the feeding period. The synergistic effect for the formation of HCN existed in the pyrolysis of acid-washed parent coal. 13 refs., 3 figs., 3 tabs.

Lin, J.; Zhao, Y.; Chang, L.; Li, W.; Xie, K. [Taiyuan University of Technology, Taiyuan (China). Key Lab of Coal Science and Technology of MOE and Shanxi Province

2004-06-01

225

A Comparison of Lignin, Macroalgae, Wood and Straw Fast Pyrolysis  

DEFF Research Database (Denmark)

A fast pyrolysis study on lignin and macroalgae (non-conventional biomass) and wood and straw (conventional biomass) were carried out in a pyrolysis centrifugal reactor at pyrolysis temperature of 550 ºC. The product distributions and energy recoveries were measured and compared among these biomasses. The fast pyrolysis of macroalgae showed a promising result with a bio-oil yield of 65 wt% dry ash free basis (daf) and 76 % energy recovery in the bio-oil while the lignin fast pyrolysis provides a bio-oil yield of 47 wt% daf and energy recovery in bio-oil of 45 %. The physiochemical properties of the bio-oils were characterized with respect to higher heating value (HHV), molecular mass distribution, viscosity, pH, density, thermal behaviors, elemental concentrations, phase separation and aging. The lignin and macroalgae oil properties were different compared to those of the wood and straw oils with respect to carbon and oxygen contents, HHV, thermal behaviors and mean molecular weight. The HHV of wood, straw, lignin and algae oils were 24.0, 23.7, 29.7 and 25.7 MJ/kg db, respectively. The distributions of metals, Cl and S in char and bio-oil were investigated for the biomasses. Almost all the metals (Al, Ca, Fe, K, Mg, Na, P and Si) were contained in the chars at the pyrolysis temperature of 550 ºC. The char properties were characterized and their potential applications are discussed.

Trinh, Ngoc Trung; Jensen, Peter Arendt

2013-01-01

226

Rapid pyrolysis of leaves and agricultural residues  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this study is the pyrolysis and gasification of agricultural and forest biomass to recover them as energy resource or raw materials for chemical industry. Four kinds of leaves and two kinds of agricultural residues were pyrolyzed. Konara leaves and straw were employed as the samples. Pyrolysis yields of Konara sapwood and leaves and that of straw were shown. The effect of the temperature was similar for them, but the yields of char differed widely between the two. The gas from the leaves contained less carbon monoxide, more ethylene, and more C2, C3 and C4 hydrocarbons in the temperature range of 873 to 973K than that from the sapwood. Leaves produced less gas/kg but more high grade calorific power as compared with sapwood and agricultural residues. To increase gas yield and minimize distillate rate of leaves, it is recommended to pyrolyze at the highest possible temperature. However, it is recommended to perform pyrolysis at 973K to obtain gas with a high carolific power. (3 figs, 5 tabs, 23 refs)

Anzai, Akira; Tada, Yutaka

1987-11-10

227

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

Energy Technology Data Exchange (ETDEWEB)

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

228

Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part I. Influence of temperature, biomass species and solid heat carrier on the behaviour of heavy metals  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Presently, little or no information of implementing fast pyrolysis for looking into the potential valorisation of heavy metal contaminated biomass is available. Fast pyrolysis of heavy metal contaminated biomass (birch and sunflower), containing high amounts of Cd, Cu, Pb and Zn, resulting from phyt...

LIEVENS, Caroline; YPERMAN, Jan; VANGRONSVELD, Jaco; CARLEER, Robert

229

Thermochemical conversion of biomass: A study on the pyrolysis of biomass  

Energy Technology Data Exchange (ETDEWEB)

The thermal treatment of biomass in absence of oxidizing agents is known as pyrolysis, the pyrolysis is a very important process to produce solid, liquid, and gaseous fuels, and is the first step of combustion and gasification processes. The understanding of the govern pyrolysis mechanisms and the knowledge of their rate and distribution of products is extremely useful for the development of the conversion processes of biomass and the proper design of the reactor for their realization. Experimental studies carried out in bench-scale reactors and pilot plant reveal the role of the most significant process parameters: temperature, solid residence time, particle size, chemical composition of feedstock, heating rate. The values of these parameters strongly influence the rate of pyrolysis as well as the distribution of products. In this paper they present the experimental results obtained in a conventional pyrolysis process and a fast pyrolysis process.

Lucchesi, A.; Maschio, G. (Universita' di Pisa (Italy))

1989-01-01

230

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

Energy Technology Data Exchange (ETDEWEB)

A process of 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.

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

1994-01-01

231

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

UK PubMed Central (United Kingdom)

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

Ismadji S; Sudaryanto Y; Hartono SB; Setiawan LE; Ayucitra A

2005-08-01

232

Separation of liquid fractions obtained from flash pyrolysis of asphaltite  

Energy Technology Data Exchange (ETDEWEB)

The experiments on the flash pyrolysis of asphaltite (Avgamasya, Sirnak, SE Anatolia, Turkey) were carried out in a fixed bed reactor as a basic study. The investigation focused on the effects of pyrolysis temperature and asphaltite particle size on the product distribution and composition. Sample particle size sieve analysis of asphaltite was performed. Liquefaction of asphaltite, different particle size, and using flash pyrolysis was performed in a fixed bed reactor with a heating rate 40 C min{sup -1} at a temperature ranging from 400 to 800 C under nitrogen atmosphere. The effect of particle size and temperature on conversion and liquid yield was examined. The yield of asphaltite liquid at the condition of -0.60 + 0.25 mm and 550 C at reached a maximum 11.13 wt%. An optimum temperature for the liquid yield was found to be 550 C. The oil product was distilled by fractionally distillation to separate component. The pyrolysis studies provide important quantitative information on the identity, composition and structure of asphaltites. Oil was treated silica gel column chromatography. Using n-hexane, toluene and methanol, the oil was separated into aliphatic, aromatic and polar components, respectively. For further structural analysis, the pyrolysis oils aliphatic, aromatic and polar subfractions were conducted using FTIR. The results of this study provide fundamental data and optimal conditions to maximize light oils yields. (author)

Saydut, Abdurrahman [Dicle University, Engineering and Architecture Faculty, Mining Engineering Department, TR-21280 Diyarbakir (Turkey); Duz, M. Zahir; Tonbul, Yalcin; Baysal, Akin; Hamamci, Candan [Dicle University, Science and Art Faculty, Chemistry Department, TR-21280 Diyarbakir (Turkey)

2008-01-15

233

Hydrogen-rich gaseous products from tea waste by pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Hydrogen from solid wastes is produced by pyrolysis. In this study, tea factory waste samples were subjected to direct and catalytic pyrolysis to obtain hydrogen-rich gaseous products at desired temperatures. The samples, both untreated and impregnated with the catalyst, were pyrolyzed at temperatures of 775, 850, 925, 975, and 1025 K. The total volume and the yield of gas from both forms of pyrolysis increase with increasing temperature. The largest hydrogen-rich gas yield obtained from tea waste, using about 13% ZnCl{sub 2} as a catalyst at about 1025 K temperature, is 60.3%, respectively. In general, in the pyrolysis of tea waste, the yield of hydrogen-rich gaseous product increases with ZnCl{sub 2} catalyst, but the yield of pyrolytic gas decreases in spite of increasing the yield of charcoal and liquid products. The catalytic effect of Na{sub 2}CO{sub 3} was greater than that of K{sub 2}CO{sub 3} for pyrolysis of the tea waste. (author)

Caglar, A.; Demirbas, A.

2001-09-01

234

Kinetics of biomass and coal pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The isothermal pyrolysis of 100 mg samples of cellulose (Whatman CF11), xylan (ex larch wood), lignin (Indulin AT), wood (Ponderosa pine sawdust), newsprint, 1% HCl washed newsprint and lignite (North Dakota) at pressures below 1 torr has been examined. Data are presented to describe the production yield as a function of time and temperature, for temperatures up to 465{degree}C for cellulosic materials and up to 540{degree}C for lignite. Pyrolysis occurs via an initial reaction followed by an isothermal reaction which can be modeled as first order in terms of remaining substrate, with tars and char forming by two competitive pseudo first order reactions. Cellulose was found to undergo an incubation period prior to rapid thermal degradation. For all other substrates, the initial reaction has been modeled as a zero order reaction. At higher pressures (> 1 torr) tars undergo secondary decomposition. A one parameter model is developed to describe the effect of ambient pressure on tar yield for newspring, wood and lignite. Data are presented for tar enhancement due to dilute acid wash pretreatment for newsprint. Acid washing pretreatment removes inorganic impurities, reducing the catalytic effect favoring the dehydration reaction. Trace amounts of acid (up to 0.02 m eq/g) catalyze the depolymerization reaction, giving 40% more tars in low pressure pyrolysis than untreated newsprint. But, additional amounts of acid lead to lower tar yields.

Agrawal, R.K.

1984-01-01

235

Pyrolysis of low rank Canadian coals  

Energy Technology Data Exchange (ETDEWEB)

A bench scale fluidized bed reactor with a continuous feed rate of 15-30 g/h has been developed to study the flash pyrolysis of coal at atmospheric pressure. The pyrolysis behaviour of four low rank Canadian coals has been investigated at 0.44 s apparent vapour residence time over a temperature range of 500-800/sup 0/C. Conditions for maximum liquid yield have been determined for each of the coals. Material balances on all products were generally satisfactory. Variation of vapour residence time from 0.2 to 1.4 s showed that the maximum liquid yield was obtained at the minimum residence time. Use of different particle sizes indicated that an optimum size probably exists for a given set of reaction conditions. Use of a hydrogenation catalyst did not increase liquid yields and the nature of the reaction atmosphere had only a minor effect on liquid yields. The H/C ratio of both the pyrolysis oil and the char decreased with increasing temperature. The maximum tar yields from lignite can be approximately correlated with the atomic H/C ratio of the parent coals. 12 tabs., 20 figs., 18 refs.

Scott, D.S.; Piskorz, J.; Fouda, S.

1986-06-01

236

Pyrolysis of Precambrian kerogens: constraints and capabilities.  

UK PubMed Central (United Kingdom)

Precambrian kerogens are currently considered to be the primary candidates for the search of biochemical fossils. Degradation of kerogens by relatively "mild" pyrolysis techniques, such as under high vacuum, can liberate indicative structural moieties which were incorporated in, and perhaps shielded by, these solid and highly condensed, basically aromatic substances. It is necessary to observe analytical constraints (sample size and shape, temperature, pressure, time, etc.) in order to prevent an overabundant yield of secondary pyrolyzates (inter- and intramolecular rearrangements) which can prevent kerogen characterization. Potential biochemical fossils have been found in Precambrian kerogens. Demonstratable syngenetic biochemical fossils are expected after kerogen diagenesis and catagenesis is understood in sufficient detail, and when pyrolysis is augmented by multiple, improved analytical techniques.

Nagy B

1982-01-01

237

Biomass pyrolysis with an entrained flow reactor  

Energy Technology Data Exchange (ETDEWEB)

A tubular entrained flow reactor has been used to study the effect of process variables on biomass pyrolysis. In this type of reactor, finely ground biomass particles are entrained by carrier gas and transported through a reactor tube which is heated to about 900/sup 0/C. Biomass particles pyrolyze as a result of heat transfer from the reactor wall yielding a gas composed primarily of carbon monoxide, carbon dioxide, hydrogen, methane, and unsaturated hydrocarbons. In this experimental program three dependent variables, percent conversion to gas, gas composition, and process heat, have been measured as a function of several process control variables. These process variables include reactor temperature, carrier gas to biomass flow ratio, reactor residence time, biomass particle size, and reactor Reynolds number. The data allow one to design and predict the performance of large-scale reactors and also elucidate heat transfer mechanisms in biomass pyrolysis.

Bohn, M.S.; Benham, C.B.

1984-02-01

238

Pyrolysis oil as diesel fuel  

Energy Technology Data Exchange (ETDEWEB)

Wood waste pyrolysis oil is an attractive fuel alternative for diesel engine operation. The main benefit is the sustainability of the fuel. No fossil reserves are consumed. The fact that wood waste pyrolysis oil does not contribute to CO{sub 2} emissions is of utmost importance. This means that power plants utilising pyrolysis oil do not cause additional global warming. Equally important is the reduced sulphur emissions that this fuel alternative implies. The sulphur content of pyrolysis oil is extremely low. The high water content and low heating value are also expected to result in very low NO{sub x} emissions. Utilisation of wood waste pyrolysis oil in diesel engines, however, involves a lot of challenges and problems to be solved. The low heating value requires a new injection system with high capacity. The corrosive characteristics of the fluid also underline the need for new injection equipment materials. Wood waste pyrolysis oil contains solid particles which can clog filters and cause abrasive wear. Wood waste pyrolysis oil has proven to have extremely bad ignition properties. The development of a reliable injection system which is able to cope with such a fuel involves a lot of optimisation tests, redesign and innovative solutions. Successful single-cylinder tests have already been performed and they have verified that diesel operation on wood pyrolysis oil is technically possible. (orig.)

Gros, S. [Wartsila Diesel International Ltd., Vaasa (Finland). Diesel Technology

1996-12-31

239

Slow-pyrolysis and -oxidation of different biomass fuel samples.  

UK PubMed Central (United Kingdom)

Pyrolysis and oxidation characteristics of some biomass samples such as almond shell, walnut shell, hazelnut shell, tobacco waste, and rapeseed were investigated using Thermogravimetric Analysis (TGA) technique under slow heating conditions (20 K/min) from ambient to 1173 K. Pyrolysis experiments were carried out under dynamic nitrogen atmosphere of 40 mL/min. Dry air was used at the same rate in the oxidation experiments. The rates of mass losses from the biomass samples regarding temperature were obtained from the Differential Thermogravimetric Analysis (DTG) curves, and these rates were interpreted according to the pyrolysis and oxidation characteristics of the biomass samples. Since the heating rate was relatively very slow, individual peaks on the DTG curves resulting from the pyrolysis or oxidation of the major constituents that forming the complex structure of the biomass samples could be survived and distinguished from the thermograms. The maximum rates of mass losses (dm/dt)max from the oxidation experiments were determined to be higher than those from the pyrolysis experiments. On the other hand, the (dm/dt)max values were determined at about 550 K for pyrolysis, whereas they were below 500 K in case of oxidation irrespective of the type of the biomass samples.

Haykiri-Acma H; Yaman S

2006-01-01

240

Kinetics of scrap tyre pyrolysis under vacuum conditions  

International Nuclear Information System (INIS)

[en] Scrap tyre pyrolysis under vacuum is attractive because it allows easier product condensation and control of composition (gas, liquid and solid). With the aim of determining the effect of vacuum on the pyrolysis kinetics, a study has been carried out in thermobalance. Two data analysis methods have been used in the kinetic study: (i) the treatment of experimental data of weight loss and (ii) the deconvolution of DTG (differential thermogravimetry) curve. The former allows for distinguishing the pyrolysis of the three main components (volatile components, natural rubber and styrene-butadiene rubber) according to three successive steps. The latter method identifies the kinetics for the pyrolysis of individual components by means of DTG curve deconvolution. The effect of vacuum in the process is significant. The values of activation energy for the pyrolysis of individual components of easier devolatilization (volatiles and NR) are lower for pyrolysis under vacuum with a reduction of 12 K in the reaction starting temperature. The kinetic constant at 503 K for devolatilization of volatile additives at 0.25 atm is 1.7 times higher than that at 1 atm, and that corresponding to styrene-butadiene rubber at 723 K is 2.8 times higher. Vacuum enhances the volatilization and internal diffusion of products in the pyrolysis process, which contributes to attenuating the secondary reactions of the repolymerization and carbonization of these products on the surface of the char (carbon black). The higher quality of carbon black is interesting for process viability. The large-scale implementation of this process in continuous mode requires a comparison to be made between the economic advantages of using a vacuum and the energy costs, which will be lower when the technologies used for pyrolysis require a lower ratio between reactor volume and scrap tyre flow rate.

2009-01-01

 
 
 
 
241

Catalytic pyrolysis of heavy oils. 8-lump kinetic model  

Energy Technology Data Exchange (ETDEWEB)

A new 8-lump kinetic model is proposed to describe the heavy oil catalytic pyrolysis process. The kinetic model contains 17 kinetic constants and one for catalyst deactivation. This paper also presents a new catalyst deactivation model, a function of feed properties and operating conditions, in which the deactivation constant does not vary with reaction temperature. Kinetic constants and apparent activation energies were determined by the least square regression analysis of the experimental data, obtained in a confined fluidized bed reactor at temperatures of 600, 630, 660 and 700C. Most of the apparent activation energies are higher than 100kJ/mol, between the apparent activation energies for catalytic cracking and those for thermal cracking. The predicted results indicate that catalytic pyrolysis of heavy oils had better be conducted at high temperature and short residence time of oil gas, and heavy oils with the aromaticity higher than 30% had better not be considered as the feeds of catalytic pyrolysis. (author)

Meng, Xianghai; Xu, Chunming; Gao, Jinsen; Li, Li [State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Changping, Beijing 102249 (China)

2006-02-10

242

Experimental and theoretical investigation of heat and mass transfer processes during wood pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Thermal decomposition of 25.4 mm diameter dry wood spheres is studied both experimentally and theoretically. Wood spheres were pyrolyzed in a vertical tube furnace at temperatures ranging from 638 K to 879 K. Mass loss and temperatures of the sample were measured during pyrolysis. Center temperature measurements showed two distinct thermal events consisting of sequential endothermic and exothermic reactions. A numerical investigation of these endo/exothermic reactions using various pyrolysis kinetics models was conducted to determine the pyrolysis mechanism and the heats of the pyrolysis reactions. A comparison of the experimental and numerical results showed that (i) Contrary to the suggestions in the literature, the contributions of the secondary tar decomposition and lignin decomposition to the center temperature exothermic peak are small. (ii) Exothermic decomposition of the intermediate solid is responsible for the center temperature peak. (iii) The center temperature plateau is caused by the endothermic decomposition of cellulose. (iv) Internal pressure generation was found to be quite important because it controls the pyrolyzate mass transfer and thus affects both the heat transfer and the residence time of the pyrolysis gases for secondary decomposition. Based on the experimental and numerical results, a new wood pyrolysis model is proposed. The model consists of three endothermic parallel reactions producing tar, gas and intermediate solid and subsequent exothermic decomposition of the intermediate solid to char and exothermic decomposition of tar to char and gas. The proposed pyrolysis model shows good agreement with the experiments. Pressure calculations based on the new pyrolysis model revealed that high pressure is generated inside the biomass particle during pyrolysis and sample splitting was observed during the experiments. The splitting is due to both weakening of the structure and internal pressure generation during pyrolysis. At low heating rates, structural weakness is the primary factor, whereas at high heating rates, internal pressure is the determining factor. It is expected that moisture, while not considered in this work will have a similar effect, but at lower temperatures. (author)

Park, Won Chan; Atreya, Arvind [Department of Mechanical Engineering, University of Michigan, 2158 GGBL 2350 Hayward St., Ann Arbor, MI 48109 (United States); Baum, Howard R. [Department of Fire Protection Engineering, University of Maryland, 3106-D J.M. Patterson Building, College Park, MD 20742 (United States)

2010-03-15

243

Effect of ethane addition on propane pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of propane/argon mixture in the presence of trace quantities (0.1% and 0.9%) of ethane was investigated at reflected shock wave temperatures between 1200 and 2000K. Trances of ethane accelerated propane decomposition at high temperatures. However, increase in the quantity of ethane added to propane/argon mixture did not result in the same increase of its accelerating influence. Ethylene, methane and acetylene were the main hydrocarbon reaction products, with small quantities of propylene and ethane detected only at lower temperatures. Below 1500K, addition of ethane slightly enhanced the yields of ethylene and methane at the expense of propylene and ethane respectively. The selectivity for acetylene increased with increasing temperature and with the decline of those for the other products. For none of the products, did the presence of ethane alter the relationship between product formation rates and temperature. The influence of ethane addition on propane pyrolysis at high temperatures was explained in terms of increased radical concentrations, especially hydrogen atoms and vinyl radicals, formed at high conversions. These accounted for the rapid acceleration of propane decomposition and the high yield of acetylene at high temperatures.

Wami, E.N.

1988-08-01

244

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

245

Pyrolysis of cassava rhizome in a counter-rotating twin screw reactor unit.  

Science.gov (United States)

A counter-rotating twin screw reactor unit was investigated for its behaviour in the pyrolysis of cassava rhizome biomass. Several parameters such as pyrolysis temperature in the range of 500-700°C, biomass particle size of twin screw reactor was relatively low, whereas the solids content was relatively high, compared to some other reactor configurations. PMID:23669070

Sirijanusorn, Somsak; Sriprateep, Keartisak; Pattiya, Adisak

2013-04-13

246

Modelingof Acetylene Pyrolysis under Steel Vacuum Carburizing Conditions in a Tubular Flow Reactor  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the present work, the pyrolysis of acetylene was studied under steel vacuumcarburizing conditions in a tubular flow reactor. The pyrolysis temperature ranged from650 °C to 1050 °C. The partial pressure of acetylene in the feed mixture was 10 and 20mbar, respectively, while the rest of the m...

Rafi Ullah Khan; Siegfried Bajohr; Frank Graf; Rainer Reimert

247

Implications of the pyrolysis system in the structural changes of vitrinite and effect on its reflectance  

Energy Technology Data Exchange (ETDEWEB)

A comparison of the transformation of vitrinite during thermal treatment through open and confined pyrolysis is presented. Open pyrolysis seemed to be more suitable for studying the effect of changes in the physico-chemical structure on vitrinite reflectance with increase in temperature. 7 refs., 4 figs.

Iglesias, M.J.; Jimenez, A.; Laggoun-Defarge, F.; Suarez-Ruiz, I. [Instituto Nacional del Carbon, Oviedo (Spain)

1999-07-01

248

Extent of pyrolysis impacts on fast pyrolysis biochar properties.  

UK PubMed Central (United Kingdom)

A potential concern about the use of fast pyrolysis rather than slow pyrolysis biochars as soil amendments is that they may contain high levels of bioavailable C due to short particle residence times in the reactors, which could reduce the stability of biochar C and cause nutrient immobilization in soils. To investigate this concern, three corn ( L.) stover fast pyrolysis biochars prepared using different reactor conditions were chemically and physically characterized to determine their extent of pyrolysis. These biochars were also incubated in soil to assess their impact on soil CO emissions, nutrient availability, microorganism population growth, and water retention capacity. Elemental analysis and quantitative solid-state C nuclear magnetic resonance spectroscopy showed variation in O functional groups (associated primarily with carbohydrates) and aromatic C, which could be used to define extent of pyrolysis. A 24-wk incubation performed using a sandy soil amended with 0.5 wt% of corn stover biochar showed a small but significant decrease in soil CO emissions and a decrease in the bacteria:fungi ratios with extent of pyrolysis. Relative to the control soil, biochar-amended soils had small increases in CO emissions and extractable nutrients, but similar microorganism populations, extractable NO levels, and water retention capacities. Corn stover amendments, by contrast, significantly increased soil CO emissions and microbial populations, and reduced extractable NO. These results indicate that C in fast pyrolysis biochar is stable in soil environments and will not appreciably contribute to nutrient immobilization.

Brewer CE; Hu YY; Schmidt-Rohr K; Loynachan TE; Laird DA; Brown RC

2012-07-01

249

Non-thermal radio frequency and static magnetic fields increase rate of hemoglobin deoxygenation in a cell-free preparation.  

UK PubMed Central (United Kingdom)

The growing body of clinical and experimental data regarding electromagnetic field (EMF) bioeffects and their therapeutic applications has contributed to a better understanding of the underlying mechanisms of action. This study reports that two EMF modalities currently in clinical use, a pulse-modulated radiofrequency (PRF) signal, and a static magnetic field (SMF), applied independently, increased the rate of deoxygenation of human hemoglobin (Hb) in a cell-free assay. Deoxygenation of Hb was initiated using the reducing agent dithiothreitol (DTT) in an assay that allowed the time for deoxygenation to be controlled (from several min to several hours) by adjusting the relative concentrations of DTT and Hb. The time course of Hb deoxygenation was observed using visible light spectroscopy. Exposure for 10-30 min to either PRF or SMF increased the rate of deoxygenation occurring several min to several hours after the end of EMF exposure. The sensitivity and biochemical simplicity of the assay developed here suggest a new research tool that may help to further the understanding of basic biophysical EMF transduction mechanisms. If the results of this study were to be shown to occur at the cellular and tissue level, EMF-enhanced oxygen availability would be one of the mechanisms by which clinically relevant EMF-mediated enhancement of growth and repair processes could occur.

Muehsam D; Lalezari P; Lekhraj R; Abruzzo P; Bolotta A; Marini M; Bersani F; Aicardi G; Pilla A; Casper D

2013-01-01

250

Non-thermal radio frequency and static magnetic fields increase rate of hemoglobin deoxygenation in a cell-free preparation.  

Science.gov (United States)

The growing body of clinical and experimental data regarding electromagnetic field (EMF) bioeffects and their therapeutic applications has contributed to a better understanding of the underlying mechanisms of action. This study reports that two EMF modalities currently in clinical use, a pulse-modulated radiofrequency (PRF) signal, and a static magnetic field (SMF), applied independently, increased the rate of deoxygenation of human hemoglobin (Hb) in a cell-free assay. Deoxygenation of Hb was initiated using the reducing agent dithiothreitol (DTT) in an assay that allowed the time for deoxygenation to be controlled (from several min to several hours) by adjusting the relative concentrations of DTT and Hb. The time course of Hb deoxygenation was observed using visible light spectroscopy. Exposure for 10-30 min to either PRF or SMF increased the rate of deoxygenation occurring several min to several hours after the end of EMF exposure. The sensitivity and biochemical simplicity of the assay developed here suggest a new research tool that may help to further the understanding of basic biophysical EMF transduction mechanisms. If the results of this study were to be shown to occur at the cellular and tissue level, EMF-enhanced oxygen availability would be one of the mechanisms by which clinically relevant EMF-mediated enhancement of growth and repair processes could occur. PMID:23593496

Muehsam, David; Lalezari, Parviz; Lekhraj, Rukmani; Abruzzo, Provvidenza; Bolotta, Alessandra; Marini, Marina; Bersani, Ferdinando; Aicardi, Giorgio; Pilla, Arthur; Casper, Diana

2013-04-12

251

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

Energy Technology Data Exchange (ETDEWEB)

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

252

Model based reconstruction for simultaneously imaging cerebral blood flow and De-oxygen hemoglobin distribution.  

UK PubMed Central (United Kingdom)

Laser speckle imaging (LSI) and optical intrinsic signal (OIS) imaging are shown to produce high resolution information of cerebral blood flow(CBF) and de-oxygen hemoglobin(dHb) respectively. However, the cortex curvature and non-uniform illumination always result in the inhomo-geneous impact and thus distort the CBF and dHb results. In this paper, we propose to extract both CBF and dHb images from raw speckle images. A parametric model for such inhomogeneity is estimated by adaptive window median-mean filtering and curve fitting technique to reconstruct the CBF and dHb image.

Miao P; Li N; Rege A; Tong S; Thakor N

2009-01-01

253

Calculated yields of ammonia in the radiolysis of deoxygenated solutions of glycylglycine  

Energy Technology Data Exchange (ETDEWEB)

This paper presents detailed Monte Carlo simulations of physical and chemical interactions occurring within electron tracks in deoxygenated solutions of glycylglycine. Hydrated electrons produced within these tracks react with the solute to produce ammonia and a peptide secondary free radical. Calculated yields of ammonia are presented for a range of solute concentrations and electron energies. Excellent agreement is found between calculated and measured yields of ammonia in solutions irradiated by 250-kVp x-rays and /sup 60/Co gamma rays. 12 refs., 5 figs.

Bolch, W.E.; Turner, J.E.; Yoshida, H.; Jacobson, K.B.

1988-01-01

254

Calculated yields of ammonia in the radiolysis of deoxygenated solutions of glycylglycine  

International Nuclear Information System (INIS)

This paper presents detailed Monte Carlo simulations of physical and chemical interactions occurring within electron tracks in deoxygenated solutions of glycylglycine. Hydrated electrons produced within these tracks react with the solute to produce ammonia and a peptide secondary free radical. Calculated yields of ammonia are presented for a range of solute concentrations and electron energies. Excellent agreement is found between calculated and measured yields of ammonia in solutions irradiated by 250-kVp x-rays and 60Co gamma rays. 12 refs., 5 figs.

1988-01-01

255

Synthesis of methyl glycosides of some alpha-isomalto oligosaccharides specifically deoxygenated at position C-2.  

UK PubMed Central (United Kingdom)

Methyl alpha-isomaltoside and methyl alpha-isomaltotrioside analogues specifically deoxygenated at position C-2 of various glucopyranosyl units were synthesized by condensation of either 6-O-acetyl-3-O-benzoyl-4-O-benzyl-1-O-tert-butyldimethylsilyl-2-deoxy- beta-D-arabino-hexopyranose (trimethylsilyl triflate mediated) or 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl chloride (mediated by silver carbonate and silver triflate) with suitably blocked derivatives of methyl alpha-D-glucopyranoside, its 2-deoxy analogue, or methyl 2'-deoxy-alpha-isomaltoside.

Petráková E; Glaudemans CP

1995-03-01

256

Polycyclic aromatic hydrocarbons in catalytically upgraded biomass pyrolysis oils  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis of biomass with catalyst upgrading was studied in a combined fluidised-bed pyrolysis unit with on-line fixed-bed zeolites catalytic upgrading; the biomass was in the form of mixed wood waste, and the catalyst used was zeolite HZSM-5. The influence of pyrolysis and catalyst conditions on the formation of polycyclic aromatic hydrocarbons (PAH) was investigated. There is much interest in PAH in the environment, since among the major chemical groups PAH comprise the largest group of carcinogens. Process parameters investigated included pyrolysis and catalyst temperature, the influence of catalyst aging and regeneration, and vapour residence time over the catalyst. It was found that polycyclic aromatic hydrocarbons in biomass pyrolysis oils were in low concentrations; however, after catalyst upgrading there was a marked rise in PAH, and their concentration reached high levels. The concentration of PAH increased with catalyst temperature. The freshly activated catalyst gave the highest concentrations of PAH, and as successive regenerations took place the catalyst became progressively less active, producing lower levels of PAH. Extended run-time with the catalyst also resulted in a less active catalyst and lower concentrations of PAH. Shorter vapour residence times produced lower concentrations of PAH. The pyrolysis oils after catalysis contained high concentrations of certain PAH which are known mutagenic and/or carcinogenic activity; for example the oils contained in tri- and tetra-methylphenanthrenes, chrysene, methylchrysenes and benzopyrenes. The influence of high PAH concentrations in a hydrocarbon product that may be used as a fuel are discussed. Work has shown a direct link between fuel PAH concentrations and PAH concentrations in emissions from both diesel engines and furnaces. The PAH concentrations in petroleum-derived fuels are much lower than those found in zeolite catalytically upgraded biomass pyrolysis oils. (author)

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

1996-12-01

257

Pyrolysis characteristics of Shenhua direct liquefaction residue  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis characteristic of Shenhua coal and Shenhua direct liquefaction residue was studied using thermal gravimetric (TG) analysis. It is found that compared with coal, the weight loss and weight loss rate of residue are higher. The weight loss process of residue can be divided into three stages: the first is before the temperature of 173{sup o}C; the second is from 173 to 510{sup o}C, in which the higher weight loss is due to the pyrolysis and volatilization of oil, asphaltene and preasphaltene in residue; the third is after 510{sup o}C, in which the weight loss is continuing. Compared with the TG and DTG curve of THF extracted residue, it is found that the majority of weight loss of residue is due to the volatilization and pyrolysis of heavy oil; and compared with the TG and DTG curve of acid washed residue, it is noted the weight loss after 649{sup o}C is mainly due to the decomposition of mineral matter and the cracking of organic compound. 10 refs., 7 figs., 2 tabs.

Chu Xijie; Li Wen; Bai Zong-qing; Li Bao-qing [Chinese Academy of Sciences, Taiyaun (China)

2009-08-15

258

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

259

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; Mohammed Mehdi Farid

2011-01-01

260

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

UK PubMed Central (United Kingdom)

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.

Yang X; Sun L; Xiang J; Hu S; Su S

2013-02-01

 
 
 
 
261

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

2012-08-27

262

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 500–800 °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.

Hongfang Chen; Yin Wang; Guangwen Xu; Kunio Yoshikawa

2012-01-01

263

Autothermal fluidized bed pyrolysis of Cuban pine sawdust  

Energy Technology Data Exchange (ETDEWEB)

Oxidative pyrolysis of Cuban pine sawdust was investigated using an autothermal fluidized bed reactor. Biomass particles were fed continuously (8.13 Kg/h) in a bed, fluidized by air gas. Experiments were conduced at three different dimensionless air factors 1, 1.5, and 2 (defined as ratio of actual air flow rate to stoichiometric air flow rate). The various physical and chemical characteristics of the pyrolysis products acquired in these conditions were identified. The results indicated that (1) the operating temperature can be correlated with the air factor; (2) the higher air factor promotes high temperature and contributes to the secondary reactions, which lead to less liquid; (3) the physicochemical characterization of the pyrolysis products indicated that the air factor, in the range studied, does not have a notable influence in their properties; (4) the liquid and char products obtained may be a potentially valuable source of chemical feedstocks. (Author)

Suarez, J.; Beaton, P. [University of the Orient, Santiago de Cuba (Cuba). Faculty of Mechanical Engineering; Zanzi, R.; Grimm, A. [Royal Inst. of Technology, Stockholm (Sweden). Dept. of Chemical Engineering and Technology

2006-06-15

264

Characterization of bio-oil obtained from fruit pulp pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Apricot pulps was pyrolyzed in a fixed-bed reactor under different pyrolysis conditions to determine the role of final temperature, sweeping gas flow rate and steam velocity on the product yields and liquid product composition with a heating rate of 5 deg. C/min. Final temperature range studied was between 300 and 700 deg. C and the highest liquid product yield was obtained at 550 deg. C. Liquid product yield increased significantly under nitrogen and steam atmospheres. For the optimum conditions, pyrolysis of peach pulp was furthermore studied. Liquid products obtained under the most suitable conditions were characterized by FTIR and {sup 1}H-NMR. In addition, gas chromatography/mass spectrophotometer was achieved on all pyrolysis oils. Characterization showed that bio-oil could be a potential source for synthetic fuels and chemical feedstock.

Ozbay, Nurguel [Bozueyuek Vocational School, Bilecik University, Bozueyuek, Bilecik (Turkey); Apaydin-Varol, Esin; Burcu Uzun, Basak [Department of Chemical Engineering, Anadolu University, Eskisehir (Turkey); Eren Puetuen, Ayse [Department of Chemical Engineering, Anadolu University, Eskisehir (Turkey)], E-mail: aeputun@anadolu.edu.tr

2008-08-15

265

Characterization of bio-oil obtained from fruit pulp pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Apricot pulps was pyrolyzed in a fixed-bed reactor under different pyrolysis conditions to determine the role of final temperature, sweeping gas flow rate and steam velocity on the product yields and liquid product composition with a heating rate of 5{sup o}C/min. Final temperature range studied was between 300 and 700{sup o}C and the highest liquid product yield was obtained at 550{sup o}C. Liquid product yield increased significantly under nitrogen and steam atmospheres. For the optimum conditions, pyrolysis of peach pulp was furthermore studied. Liquid products obtained under the most suitable conditions were characterized by FTIR and {sup 1}H-NMR. In addition, gas chromatography/mass spectrophotometer was achieved on all pyrolysis oils. Characterization showed that bio-oil could be a potential source for synthetic fuels and chemical feedstock. (author)

Oezbay, Nurguel [Bozueyuek Vocational School, Bilecik University, Bozueyuek, Bilecik (Turkey); Apaydin-Varol, Esin; Burcu Uzun, Basak; Eren Puetuen, Ayse [Department of Chemical Engineering, Anadolu University, Eskisehir (Turkey)

2008-08-15

266

Progress in coal pyrolysis research  

Energy Technology Data Exchange (ETDEWEB)

This paper considers some of the recent progress in both the improved understanding and the identification of areas uncertainty with regard to coal pyrolysis, rates, and mechanisms. The paper addressed two questions: (1) what are the controlling chemical factors in coal pyrolysis? (2) what are the controlling physical factors in coal pyrolysis? The problem of answering the questions is that multiple chemical reactions occur whose results depend on how the reactants are bound in the coal macromolecular network. Species-selective transport of the reactants and products further complicate the interpretations. In what follows, we have tried to focus on topics where answers are needed or where significant new progress is being made.

Solomon, P.R.; Serio, M.A. [Advanced Fuel Research, Inc., East Hartford, CT (United States)

1994-12-31

267

Determination of heats of pyrolysis and thermal reactivity of peats  

Energy Technology Data Exchange (ETDEWEB)

Heats of pyrolysis of four Finnish peats were determined by differential scanning calorimetry (d.s.c.), and combustion enthalpies were compared by differential thermoanalysis (DTA) in an air atmosphere. Weight loss data obtained by thermogravimetric analysis (TGA) were combined with the enthalpy data. The heats of pyrolysis of the peats varied between 120 and 250 kJkg{sup -}{sup 1}. These values were used to model the combustion and pyrolysis of small peat particles (typical in pulverized fuel combustion) and large peat particles (typical in grate combustion). TGA and DTA together gave useful information about the reactivity of peat in an oxidizing atmosphere with changing temperature, despite the similar shapes of the derived TGA (DTG) and DTA-curves. The pyrolysis and combustion behaviour of the peat with the lowest degree of decomposition was similar to that of cellulose, and the differences in the peats were apparent with all the methods used (d.s.c. DTA and TGA). The initial temperatures of pyrolysis and combustion were lower with peats of high ash content (inorganic material) and the combustion proceeded through more steps than with the peats of low ash content. 13 refs., 4 figs., 1 tab.

Aho, M.J.; Tummavuori, J.L.; Haemaelaeinen, J.P.; Saastamoinen, J.J. (Technical Research Centre of Finland, Jyvaeskylae)

1989-09-01

268

The contribution of high-temperature pyrolysis to industrial development after World War II. From coal chemistry to petrochemistry; Der Beitrag des Hochtemperatur-Pyrolyse-Verfahrens zu dieser Entwicklung nach dem Zweiten Weltkrieg. Der Wandel von der Kohlen- zur Petrochemie  

Energy Technology Data Exchange (ETDEWEB)

After the Second World War when the base of raw materials had changed from coal to petrol, the chemical industry was confronted with crucial technological problems: Whilst acetylen derived from coal had, due to the increased cost of coal and energy, turned to be more and more non-profitable ethylen as a crack-product of naphta succeeded in being steadily produced in a more profitable way and therefore came to be the most important base-product for aliphatic and macro-molecular chemistry. In Germany, however, to begin with, hydrocarbon fractions for producing ethylen were not available in sufficient quantities: Moreover there were no chemical procedures in order to manufacture derivates based on ethylen. This economical situation led to the development of a petrochemical procedure simultaneously producing acetylen as well as ethylen: The so-called 'High-temperature-pyrolysis' ('HTP') with a capacity of 82,000 tons p.a. including both monomeres. The report takes into consideration thermodynamical aspects of the cracking reaction, describes the procedure and its historical development and ends in viewing the efforts of that time to transfer the HTP-principle to the cracking of crude oil. (orig.)

Wetzel, W.

2001-03-01

269

Measurement of intracellular pH and deoxyhemoglobin concentration in deoxygenated erythrocytes by phosphorus-31 nuclear magnetic resonance.  

UK PubMed Central (United Kingdom)

Deoxygenation of erythrocytes produced marked changes in their 31P nuclear magnetic resonance spectra in the superconducting spectrometer. Most significantly, all intracellular and extracellular phosphates underwent downfield shifts. In fully deoxygenated blood the extracellular phosphates showed downfield shifts that were dependent upon packed cell volume, when added pyrophosphate was used as a measure of extracellular chemical shift behavior. This effect on extracellular signals was attributed to the paramagnetic contribution of deoxyhemoglobin to the "bulk" magnetic susceptibility of the red cell suspension. Line broadening was observed in deoxygenated whole cell systems but not in hemolysates, as a result of paramagnetic susceptibility gradients across the cell membrane. The degree of downfield shift upon deoxygenation was of different magnitude for each intracellular phosphate [2-P of 2,3-diphosphoglycerate (2,3-DPG) greater than 3-P of 2,3-DPG greater than inorganic phosphate greater than ATP phosphates], independent of packed cell volume but dependent on the degree of deoxygenation of hemoglobin. When deoxygenation shift effects in adult cells were compared to those of cord blood cells containing 70% fetal hemoglobin, it was found that 45% of the 2,3-DPG shift effects were attributable to binding of that compound to hemoglobin. By use of a nonphysiologic phosphate analogue, methylphosphonate, as an internal reference, it was found that an increase in pH of deoxy cells contributed to the downfield shift of inorganic phosphate. In hemolysates, the methylphosphonate - inorganic phosphate chemical shift difference was found to be pH dependent, with a sensitivity of (-) 0.39 pH unit/ppm, independent of the hemoglobin oxygenation state.

Labotka RJ

1984-11-01

270

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

271

Pyrolysis of high sulfur Indian coals  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis experiments under laboratory conditions for five numbers of high sulfur coal samples from the states of Meghalaya and Nagaland, India, were carried out at temperatures of 450, 600, 850, and 1000{sup o}C, respectively. The yield of products and thermal release of sulfur from these coals are investigated. The distribution of sulfur in the pyrolyzed products, i.e., char/coke, gas, and tar, is also reported. Hydrocarbon and sulfurous gases released at different temperatures were analyzed by a gas chromatograph (GC) with an FID (flame ionized detector) and an FPD (flame photometric detector), respectively. H{sub 2}S evolution during coal pyrolysis was found to be a function of temperature up to 850{sup o}C. The low concentration of SO{sub 2} detected for some of the samples is due to decomposition of inorganic sulphates present. Evolution of methane for the coals tested increases with the increase of temperature. Maximum sulfur release was found in the range of 600-850{sup o}C and has a decreasing tendency from 850-1000{sup o}C, which might be due to the incorporation of sulfur released into the coal matrix. Activation energies for sulfur release were found in the range of 38-228 kJ mol{sup -1}, which were higher than the reported activation energies for lignites and bituminous coals mainly due to highly stable organic sulfur functionalities. 52 refs., 9 figs., 6 tabs.

B.P. Baruah; Puja Khare [RRL Jorhat, Assam (India). Coal Chemistry Division

2007-12-15

272

Surface morphology and chemistry of commercial carbon black and carbon black from vacuum pyrolysis of used tyres  

Energy Technology Data Exchange (ETDEWEB)

The paper reports investigations into the surface chemistry and morphology of carbon blacks obtained by pyrolysis of used tyres (CB{sub p}) and of commercial carbon blacks. In contrast to commercial carbon blacks, carbonaceous deposits are formed on the CBp surface. The concentration of these carbonaceous deposits depends on the pyrolysis conditions, decreasing with decreasing pyrolysis pressure and increasing pyrolysis temperature. The carbon black surface is smoothed by the carbonaceous deposits. A relation exists between the fractal dimension, or roughness, of the CB{sub p} surface and the amount of carbonaceous deposits at constant pyrolysis temperature. The surface chemistry and morphology of CB{sub p} from pyrolysis at low pressures are similar to those of commercial rubber-grade carbon blacks. 35 refs., 8 figs., 7 tabs.

Sahouli, B.; Blacher, S.; Brouers, F.; Darmstadt, H.; Roy, C.; Kaliaguine, S. [Universite de Liege, Liege (Belgium)

1996-08-01

273

Pyrolysis rates of biomass materials  

Energy Technology Data Exchange (ETDEWEB)

A method is proposed by which pyrolysis rates of biomass materials can be predicted from the species compositions in terms of the basic constituents (cellulose, hemicellulose and lignin) and their individual kinetic parameters. The activation energies, frequency factors and reaction orders for cellulose, hemicellulose and lignin have been determined in a conventional manner. The measured rates of pyrolysis of different biomass species (hazelnut, wood, olive husk and rice husk) compare well with literature data. (author)

Rao, T.R. [Indian Institute of Technology, New Delhi (India). Dept. of Chemical Engineering; Sharma, A. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science

1998-11-01

274

Reduced mechanisms for propane pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Reduced chemical mechanisms describing the pyrolysis of pure propane in a cracking tube with a uniform firebox temperature are presented. The full chemistry is taken from the model of Dente and Ranzi and consists of 422 reactions involving 48 species. By use of techniques for the identification of redundant species and the principal component analysis of the local rate sensitivity matrix, the mechanism is reduced to 122 reactions. The concentration profiles along the cracking tube calculated using this mechanism are within 1--5% of the profiles calculated using the full chemistry. The use of overall sensitivities and approximations involving fast reversible reactions enables the selection of a further 72 redundant reactions in the mechanism. The resulting 50-step scheme reproduces the concentrations of the major products and the main reactor features, although some minor products are poorly represented. The number of species in the model is further reduced by the application of the quasi-steady-state approximation (QSSA). The calculation of the instantaneous error induced by the QSSA and the species lifetime reveals a set of 12 QSSA species, and explicit analytical expressions for a subset of these species are presented. The substitution of these expressions results in a model containing only 12 coupled differential equations. The errors induced in the concentrations of non-steady-state species by the application of the QSSA are shown to be minimal.

Tomlin, A.S.; Pilling, M.J.; Merkin, J.H.; Brindley, J. [Univ. of Leeds (United Kingdom); Burgess, N. [ICI Chemicals and Polymers Ltd., Wilton (United Kingdom); Gough, A. [Univ. of Newcastle upon Tyne (United Kingdom). Dept. of Chemical and Processing Engineering

1995-11-01

275

Pyrolysis of furan in a microreactor.  

UK PubMed Central (United Kingdom)

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) ? ?-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 KN; Guan Q; Golan A; Daily JW; Nimlos MR; Stanton JF; Ahmed M; Ellison GB

2013-09-01

276

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) ? ?-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

277

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; Dr. N.D. MITTAL

2010-01-01

278

Pyrolysis reactor and fluidized bed combustion chamber  

Energy Technology Data Exchange (ETDEWEB)

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

279

Physical properties of flash pyrolysis liquids  

Energy Technology Data Exchange (ETDEWEB)

Process design requires knowledge of the physical and chemical properties of the fluids being handled. The measurement of a range of properties of two pyrolysis liquids is described. The properties reported are: density, viscosity, refractive index, thermal capacity, thermal conductivity, and their variation with temperature, time, exposure to air/oxygen and history. The oils follow conventional behaviour for most properties except that there is marked differences in viscosity behaviour above around 50[sup o]C compared to below 50[sup o]C. There is a noticeable effect from exposure to oxygen/air which increases viscosity. (author)

Peacocke, G.V.C.; Russell, P.A.; Jenkins, J.D.; Bridgwater, A.V. (Aston Univ., Birmingham (United Kingdom). Energy Research Group)

1994-01-01

280

Effect of pyrolysis temperature on the properties of Bi3.5La0.5Ti3O12 thin films deposited by aqueous chemical solution deposition  

International Nuclear Information System (INIS)

Bi3.5La0.5Ti3O12 thin films for ferroelectric random access memory application were fabricated by the aqueous chemical solution deposition method. The precursor films were deposited by spin coating and subsequently transformed into the oxide by thermal treatment on three hot plates and crystallizing in a rapid thermal processing furnace at a temperature as low as 650 deg. C. The temperature of the third hot plate step was varied, which affected the ferroelectric properties of the prepared films. The ferroelectric properties of the crystallized films as well as their crystallographic structure, texture and microstructure were characterized using various experimental techniques. The evolution of the precursor chemical structure of the thin films, containing organic compounds, was studied at different temperatures during the thermal treatment. In order to maximize the remanent polarization of the crystalline Bi3.5La0.5Ti3O12 thin films to approximately 6 ?C cm-2 it is preferable to remove all the organic components of the thin-film precursor prior to the intermediate crystallization step in the rapid thermal processing furnace. A temperature of 370 deg. C has been shown to be the minimal temperature for achieving the complete decomposition of the organic constituents of the precursor thin film

2005-08-15

 
 
 
 
281

Kajian Pembuatan Nanotube Karbon dengan Menggunakan Metode Spray Pyrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available Dalam penelitian ini, nanotube karbon dibuat dengan menggunakan metode spray pyrolysis tanpa menggunakan gas pembawa pada temperatur 850°C. Metode ini merupakan metode yang sering digunakan dalam sintesis nanotube karbon karena dapat menghasilkan nanotube karbon dengan kualitas yang baik dengan biaya produksi yang murah. Dalam spray pyrolysis, benzene sebagai sumber karbon terdekomposisi secara termal dengan bantuan ferrocene yang berperan sebagai katalis dalam menghasilkan nanotube karbon. Penelitian dilakukan dengan memvariasikan massa ferrocene dan waktu pemanasan. Dari hasil karakterisasi SEM dan EDX diketahui bahwa perubahan struktur dan diameter nanotube karbon dipengaruhi oleh massa ferrocene yang dilarutkan dalam benzene. Juga diketahui bahwa penambahan waktu pemanasan tidak berpengaruh pada perbaikan struktur nanotube karbon.

Fatimah A Noor; Lizi L Zaenufar; Yulkifli; Mikrajuddin Abdullah; Sukirno; Khairurrijal

2009-01-01

282

Disproportionation of lignitic coal (lignite) during high speed pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Evaluated were investigations into pyrolysis of brown coal from the Maritsa-Iztok deposit in Bulgaria. Coal with a volatile matter content of 61.1%, ash content 26.7%, moisture content 8.7% and calorific value of 19.6 MJ/kg was used. Two heating procedures were used: high speed heating at more than 500 C/s or low speed heating at 0.08 C/s. The investigations were aimed at determining disproportionation of the elementary composition of combustible matter in coal. Analyses showed that when high speed pyrolysis was used and temperature did not exceed 600 C about 40% carbon, 70% hydrogen, 30% sulfur, and 80% oxygen and nitrogen were transformed into gaseous products. When low speed heating pyrolysis was used about 27% coal, 78% hydrogen, 40% sulfur, and 100% oxygen were transformed into gaseous products. Composition of the gas produced by each method as well as proportion between carbon and hydrogen, carbon and oxygen, and carbon and hydrogen in the semicoke produced by pyrolysis of brown coal also were determined. When high speed pyrolysis was used coal tar yield was 130% higher than with the Fischer process. 9 references.

Vylkov, V.; Dimitrova, C.; Ruscev, D.

1983-04-01

283

Novel technique for coal pyrolysis and hydrogenation product analysis  

Energy Technology Data Exchange (ETDEWEB)

This report covers the second to the last quarter of the last year of the three-year grant period. In the final project year, we are focusing on the pyrolysis and oxidative pyrolysis of benzene and benzene acetylene mixtures (along with the pyrolysis of other C5-C12 compounds) in order to develop the VUV-MS technique for compounds more representative of those in coal pyrolysis applications. In the first quarters of the current project year, we have carried out the pyrolysis of mixtures of these compounds without oxygen in a microflow reactor. The acetylene/benzene mixtures were used to gain a better understanding of the mechanisms of molecular growth in such systems specifically to look at the kinetics of aryl-aryl reactions as opposed to small molecule addition to phenyl radicals. Sarofim and coworkers at MIT have recently demonstrated the importance of these reactions in coal processing environments. In the past, the growth mechanism for the formation of midsized PAH has been postulated to involve primarily successive acetylene additions to phenyl-type radicals, our work confirms this as an important mechanism especially for smaller PAH but also investigates conditions where biaryl formation can play an important role in higher hydrocarbon formation. Two different temperature regimes are considered: below 1000 K, where reactivity is dominated by molecular processes, and above 1000 K, where radical chain mechanisms become the dominant pathway. These experiments were carried out at a large range of total pressures and with different diluents.

Pfefferle, L.D.

1992-01-01

284

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...

285

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 1400°C 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

286

Use of an Apple IIe microcomputer for pyrolysis data acquisition  

Energy Technology Data Exchange (ETDEWEB)

An Apple IIe microcomputer is being used to collect data and to control a pyrolysis system. Pyrolysis data for bitumen and kerogen are widely used to estimate source rock maturity. For a detailed analysis of kinetic parameters, however, data must be obtained more precisely than for routine pyrolysis. The authors discuss the program which controls the temperature ramp of the furnace that heats the sample, and collects data from a thermocouple in the furnace and from the flame ionization detector measuring evolved hydrocarbons. These data are stored on disk for later use by programs that display the results of the experiment or calculate kinetic parameters. The program is written in Applesoft BASIC with subroutines in Apple assembler for speed and efficiency.

1988-02-01

287

A General Mathematical Model of Solid Fuels Pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The aim of this work is to present and discuss a detailed kinetic model able to describe the devolatilization process of solid fuels, under pyrolysis conditions. The major reason of this interest in a better understanding of pyrolysis and combustion of coal, biomass and solid fuels lies in the increasing concern of the environmental impact of large-scale combustion processes. The common chemical and structural aspects of the different fuels are singled out and used as the starting point to define this mathematical model. The formation of light gases and liquid tars is the first step in the pyrolysis process. A particular attention is also devoted to the generality and flexibility of numerical and mathematical methods. Several comparisons with experimental data are analysed and the molecular weight distributions of the tar from different coals evolved at different temperatures are also discussed.

Migliavacca, G.; Parodi, E. [Stazione Sperimentale per i Combustibili, San Donato Milanese MI (Italy); Bonfanti, L. [ENEL Produzione Ricerca, Pisa (Italy); Faravelli, T.; Pierucci, S.; Ranzi, E. [Department of Chemical Engineering, Politecnico di Milano, Milano (Italy)

2004-07-01

288

Pyrolysis of a waste from the grinding of scrap tyres.  

UK PubMed Central (United Kingdom)

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 N(2) 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.

Fernández AM; Barriocanal C; Alvarez R

2012-02-01

289

Specialists' workshop on fast pyrolysis of biomass  

Energy Technology Data Exchange (ETDEWEB)

This workshop brought together most of those who are currently working in or have published significant findings in the area of fast pyrolysis of biomass or biomass-derived materials, with the goal of attaining a better understanding of the dominant mechanisms which produce olefins, oxygenated liquids, char, and tars. In addition, background papers were given in hydrocarbon pyrolysis, slow pyrolysis of biomass, and techniques for powdered-feedstock preparation in order that the other papers did not need to introduce in depth these concepts in their presentations for continuity. In general, the authors were requested to present summaries of experimental data with as much interpretation of that data as possible with regard to mechanisms and process variables such as heat flux, temperatures, partial pressure, feedstock, particle size, heating rates, residence time, etc. Separate abstracts have been prepared of each presentation for inclusion in the Energy Data Base. (DMC)

1980-01-01

290

Pyrolysis of a waste from the grinding of scrap tyres.  

Science.gov (United States)

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 N(2) 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. PMID:22204837

Fernández, A M; Barriocanal, C; Alvarez, R

2011-12-13

291

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

292

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

293

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 stud...

Mario A. Sánchez-García; Arturo Maldonado; Luis Castañeda; Rutilo Silva-González; María de la Luz Olvera

294

Investigating free radicals during black coal pyrolysis using electron spin resonance  

Energy Technology Data Exchange (ETDEWEB)

Two types of black coal from Poland (gas coal and coking coal) were pyrolyzed under laboratory conditions using a heating rate of 10 C/min, a final pyrolysis temperatures of 360, 400, 510, 550 and 580 C and an argon flow rate of 5 ml/s. Chars and coke from coal pyrolysis were investigated using the Varian E6 electron spin resonance system. Two types of cells were used: a conventional fused cell and a new, specially designed flow cell. Using the flow cell, effects of gaseous pyrolysis products on the level of free radicals in chars were determined. Gaseous pyrolysis products, if not allowed to leave the reaction zone, quench free radicals in the char body. Differences of free radical formation and quenching during pyrolysis of various coal types are comparatively evaluated. 13 refs.

Stompel, Z.; Fowler, T.G.; Bartle, K.D.

1988-06-01

295

Study on the controlled unsequential pyrolysis of polyethylene to polyethylene wax with desired molecular weight range  

Energy Technology Data Exchange (ETDEWEB)

Conventionally, the pyrolysis of polyethylene (PE) has been regarded as a typically uncontrollable and sequential random chain scission to produce ethylene monomer at the beginning of the process. We find the controllable unsequential pyrolysis of PE and also successfully realized controlled unsequential pyrolysis of PE. Aimed PE wax with the desired molecular weight range was readily obtained by using controlled unsequential pyrolysis. The molecular weight range of PE wax can be reasonably controlled by designed measures. The relations of the molecular weight range to pyrolysis temperature and time are investigated as well. It has now become feasible to obtain the desired PE wax in a way that is like 'cutting' a PE chain. (Author)

Xing, J. [University of Petroleum, School of Chemical Engineering, Changping, Beijing (China)

2003-03-15

296

A study on experimental characteristic of microwave-assisted pyrolysis of microalgae.  

UK PubMed Central (United Kingdom)

The microwave-assisted pyrolysis of Chlorella vulgaris was carried out under different microwave power levels, catalysts and contents of activated carbon and solid residue. The products, pyrolysis temperature and temperature rising rate were analyzed in order to obtain the optimal conditions. The results indicated that the higher the microwave power level was, the higher the maximum temperature rising rate and pyrolysis temperature were. The maximum bio-oil yield (35.83 wt.%) and gas yield (52.37%) were achieved under the microwave power of 1500 W and 2250 W, respectively. And 2250 W was the optimal power to obtain bio-fuel product. High microwave power level and catalyst can enhance the production of gas. Catalysts can promote the pyrolysis of C. vulgaris, and activated carbon was the best among the tested catalysts followed by the solid residue. The optimal content of activated carbon is 5% with the maximum bio-fuel yield of 87.47%.

Hu Z; Ma X; Chen C

2012-03-01

297

Catalytic cross deoxygenative and dehydrogenative coupling of aldehydes and alkenes: a redox-neutral process to produce skipped dienes.  

Science.gov (United States)

A novel catalytic cross deoxygenative and dehydrogenative coupling reaction of aldehydes and alkenes was established via a cooperative catalysis approach. This transformation provided an efficient and atom-economic protocol for the synthesis of 1,4-skipped dienes from aldehydes and simple alkenes under oxidant-free reaction conditions. PMID:24030693

Qian, Bo; Zhang, Guoying; Ding, Yongzheng; Huang, Hanmin

2013-09-26

298

Effect of high-intensity interval training on the profile of muscle deoxygenation heterogeneity during incremental exercise.  

UK PubMed Central (United Kingdom)

This study examines the effect of high-intensity interval training (HIT) on the spatial distribution of muscle deoxygenation during incremental exercise. Young untrained male adults (n = 11) performed an incremental bicycle exercise before and after a running HIT of 6 weeks. Muscle deoxygenation (HHb) and blood volume (Hb(tot)) were monitored continuously by near-infrared spectroscopy at eight sites in the vastus lateralis. The rise in HHb during incremental exercise was significantly higher after training, in comparison with before training (P = 0.020), whereas the rise in Hb(tot) was not affected by training. The standard deviation of HHb and the relative dispersion of HHb at the eight sites were not significantly different irrespective of the intensity of exercise between pre- and post-training. After training, the standard deviation of HHb was greater at 60, 70, and 80 % of VO?(max) than at rest. Finally, training significantly increased the standard deviation of Hb(tot) (P = 0.036). These results indicate that HIT changes the muscle deoxygenation profile during incremental exercise, suggesting an improvement in the O(2) extraction with training. HIT did not reduce the spatial heterogeneity of muscle deoxygenation and blood volume during incremental exercise. This indicates that the intra-muscular distribution of the VO(2)/O(2) delivery ratio was not improved by 6 weeks HIT.

Prieur F; Mucci P

2013-01-01

299

Thermogravimetric analysis and kinetic study on pyrolysis of representative medical waste composition.  

Science.gov (United States)

To obtain detailed information on the pyrolysis characteristics, a thermogravimetric study on the pyrolysis of 14 typical medical waste compositions was carried out in thermogravimetric analysis (TGA) equipment using dynamic techniques in a stream of N2. An index representing pyrolysis reactivity of waste was presented. Kinetic parameters were obtained by Coats-Redfern method and used to model the TG curve. The results showed that: (a) Plastic, protein, cellulosic material, synthetic fibre, and rubber entered pyrolysis process in succession. (b) There was one decomposition stage in the pyrolysis of one-off medical glove, operating glove, cellulosic waste, absorbable catgut suture and adhesive plaster, while other components had two obvious weight loss stages. (c) The obtained apparent activation energy for second stage pyrolysis was comparably higher than that for first stage. (d) Each stage was controlled by only one kinetic mechanism, in which kinetic parameters were constant. (e) The degradation kinetics of medical waste may be affected by special physical and chemical treatment in the product manufacturing process. (f) Among 13 waste samples, the pyrolysis index of cellulosic matter was the highest, which indicated cellulosic matter had strong pyrolysis reactivity. (g) With increasing heating rate, TG curve and DTG peak shifted to high temperatures and main reaction interval of the sample became longer. PMID:17911006

Deng, Na; Zhang, Yu-feng; Wang, Yan

2007-10-01

300

Thermogravimetric analysis and kinetic study on pyrolysis of representative medical waste composition.  

UK PubMed Central (United Kingdom)

To obtain detailed information on the pyrolysis characteristics, a thermogravimetric study on the pyrolysis of 14 typical medical waste compositions was carried out in thermogravimetric analysis (TGA) equipment using dynamic techniques in a stream of N2. An index representing pyrolysis reactivity of waste was presented. Kinetic parameters were obtained by Coats-Redfern method and used to model the TG curve. The results showed that: (a) Plastic, protein, cellulosic material, synthetic fibre, and rubber entered pyrolysis process in succession. (b) There was one decomposition stage in the pyrolysis of one-off medical glove, operating glove, cellulosic waste, absorbable catgut suture and adhesive plaster, while other components had two obvious weight loss stages. (c) The obtained apparent activation energy for second stage pyrolysis was comparably higher than that for first stage. (d) Each stage was controlled by only one kinetic mechanism, in which kinetic parameters were constant. (e) The degradation kinetics of medical waste may be affected by special physical and chemical treatment in the product manufacturing process. (f) Among 13 waste samples, the pyrolysis index of cellulosic matter was the highest, which indicated cellulosic matter had strong pyrolysis reactivity. (g) With increasing heating rate, TG curve and DTG peak shifted to high temperatures and main reaction interval of the sample became longer.

Deng N; Zhang YF; Wang Y

2008-01-01

 
 
 
 
301

Thermovolumetrical studies on C/sub 1/ to C/sub 3/ hydrocarbon formation during pyrolysis of low rank fuels  

Energy Technology Data Exchange (ETDEWEB)

Laboratory pyrolysis results are presented from 6 types of brown coal (xylite, soft and hard brown coals). Pyrolysis gas was analyzed by gas chromatography on yield of methane and C/sub 2/ and C/sub 3/ hydrocarbons. Graphs for the gas yield in relation to pyrolysis temperature are provided. Experiments showed that methane yield could be increased two- to fourfold by pyrolysis with hydrogen gas at high temperatures of up to 900 C. Methane formation at lower temperatures, however, was not influenced by hydrogen gas. Maximum hydrocarbon formation velocity was observed in the 430 to 480 C temperature range. Kinetic parameters of pyrolysis reactions were further determined using formulae of H. Juentgen and K.H. van Heek. 8 refs.

Karcz, A.; Palian, E.

1986-01-01

302

Investigation of the ROPE copyright (Recycle Oil Pyrolysis and Extraction) process performance on Sunnyside tar sand  

Energy Technology Data Exchange (ETDEWEB)

The main objectives of this research were to determine the optimum pyrolysis temperature for Sunnyside tar sand and to verify the operability and efficiency of the ROPE process at steady-state conditions for production of feedstock materials. The experiments were conducted in the 2-inch screw pyrolysis reactor (SPR). Four 24-hour tests and one 105-hour test were performed in the 2-inch SPR using Sunnyside tar sand. The 24-hour tests were designed to predict the optimum pyrolysis temperature for oil yield. The 105-hour test was conducted to confirm the optimum pyrolysis temperature with sufficient operating time to reach steady-state conditions with respect to product compositions. The following conclusions can be drawn from the Sunnyside tar sand 2-inch SPR tests: (1) Sunnyside tar sand can be processed without any major operational difficulty by the ROPE process. (2) Oil yields greater than Fischer assay were obtained during the 2-inch SPR tests. Oil yield greater than 80 wt % of the bitumen was obtained from the 105-hr test. (3) The ratio of heavy oil to light product oil is strongly dependent upon the pyrolysis temperature and increases with a decrease in the reaction temperature. The gas yield increases with the increase in pyrolysis temperature but the residual carbon in the spent sand decreases with the increase in pyrolysis temperature, reaches the minimum at 675{degrees}F, and then increases with further increase in the pyrolysis temperature. ROPE process product oils from Sunnyside tar sand have market application as blending stocks for the production of diesel fuels, but they are not suited for the production of unleaded gasoline or high-density aviation turbine fuels. 3 refs., 3 figs., 17 tabs.

Cha, C.Y.; Johnson, L.A. Jr.; Guffey, F.D.

1990-07-01

303

Abuse of smoking methamphetamine mixed with tobacco: II. The formation mechanism of pyrolysis products.  

UK PubMed Central (United Kingdom)

The pyrolysis products of smoking methamphetamine mixed with tobacco were determined by gas chromatography (GC) and GC/mass spectrometry (GC/MS) methods. The mainstream smoke contained methamphetamine (14.5% of the initial methamphetamine), phenylacetone (3.1%). N-cyanomethylmethamphetamine (1.9%), trans-beta-methylstyrene (1.7%), N-formylmethamphetamine (1.5%), and other products (each less than 1%). The amount of each pyrolysis product in the sidestream smoke was less than that in the mainstream smoke by a factor of over 5, except for methamphetamine (10.5%) and N-formylmethamphetamine (1.4%). The formation mechanism of these products was investigated, by use of a pyrolyzer, from the standpoint of the material, pyrolysis temperature, and pyrolysis atmosphere. Although several products (for example, dimethylamphetamine and trans-beta-methylstyrene) were formed by thermal self-decomposition of methamphetamine alone, most of the products, except N-cyanomethylmethamphetamine, were formed chiefly by the thermal reaction of methamphetamine with cigarette components. The formation of N-cyanomethylmethamphetamine required air and a high pyrolysis temperature. Air and a high pyrolysis temperature generally accelerated the formation of the pyrolysis products.

Sekine H; Nakahara Y

1990-05-01

304

Abuse of smoking methamphetamine mixed with tobacco: II. The formation mechanism of pyrolysis products.  

Science.gov (United States)

The pyrolysis products of smoking methamphetamine mixed with tobacco were determined by gas chromatography (GC) and GC/mass spectrometry (GC/MS) methods. The mainstream smoke contained methamphetamine (14.5% of the initial methamphetamine), phenylacetone (3.1%). N-cyanomethylmethamphetamine (1.9%), trans-beta-methylstyrene (1.7%), N-formylmethamphetamine (1.5%), and other products (each less than 1%). The amount of each pyrolysis product in the sidestream smoke was less than that in the mainstream smoke by a factor of over 5, except for methamphetamine (10.5%) and N-formylmethamphetamine (1.4%). The formation mechanism of these products was investigated, by use of a pyrolyzer, from the standpoint of the material, pyrolysis temperature, and pyrolysis atmosphere. Although several products (for example, dimethylamphetamine and trans-beta-methylstyrene) were formed by thermal self-decomposition of methamphetamine alone, most of the products, except N-cyanomethylmethamphetamine, were formed chiefly by the thermal reaction of methamphetamine with cigarette components. The formation of N-cyanomethylmethamphetamine required air and a high pyrolysis temperature. Air and a high pyrolysis temperature generally accelerated the formation of the pyrolysis products. PMID:2348176

Sekine, H; Nakahara, Y

1990-05-01

305

Pyrolysis behavior of weakly reductive coals from Northwest China  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis behaviors of three weakly reductive coals from Northwest China and one reductive Pingshuo (PS) coal were investigated in a thermogravimetric analyzer and a fixed-bed reactor. The results show that the pyrolysis behaviors of the weakly reductive coals are obviously different from that of the reductive coal despite their similar elemental composition. Compared with PS coal, the weakly reductive coals exhibit a lower weight loss and a lower rate of weight loss, and the peaks corresponding to the maximum rate of weight loss shift to high temperature. During pyrolysis in a fixed-bed reactor, the conversion and tar and gas yields of all the coals increase with temperature. The weakly reductive coals have lower conversions and tar yields than PS coal in the temperature range investigated, which is accordant with the weight loss in thermogravimetric analysis. The tars from coal pyrolysis were characterized by FT-IR, ultimate analysis, and {sup 1}H NMR, and the combustion behavior of chars from different coals was compared on a thermogravimetric analyzer. 28 refs., 6 figs., 9 tabs.

Yunpeng Zhao; Haoquan Hu; Lijun Jin; Bo Wu; Shengwei Zhu [Dalian University of Technology, Dalian (China). Institute of Coal Chemical Engineering

2009-01-15

306

Co-pyrolysis of coal and used tyres  

Energy Technology Data Exchange (ETDEWEB)

Previous works performed in our laboratory, as well on coal pyrolysis as on used tyres pyrolysis, led us to propose their reciprocal upgrading by co-pyrolysis. Different proportions of waste tyre were pyrolysed between 560 and 760 C with coal in a 100 cm{sup 3} static batch reactor in a N{sub 2} atmosphere. The yields and the composition of gases, oils and chars were determined in relation to pyrolysis temperature and tyre content. An increase of temperature favours oil and gas formation. The partial substitution of coal by used tyre has a positive effect on oils production, but at high temperature, part of oils is decomposed into gas and char. The presence of scrap tyres doesn`t extract more oils from coal, but improves the oils quality, increasing the yields in light aromatic compounds (BTX) and the formation of products with high value, like limonene. The mechanical properties of the chars are not appreciably modified by addition of a low percentage of tyre to coal. (orig.)

Laurent, P.; Brackman-Danheux, C.; Fontana, A.; Lecharlier, M. [Universite Libre de Bruxelles (Belgium). Faculte des Sciences Appliquee

1997-12-31

307

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

International Nuclear Information System (INIS)

[en] 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)

2009-01-01

308

Pyrolysis methods in organic geochemistry: an overview  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis techniques can provide successful and rapid analyses of sedimentary organic material, including petroleums, coals, oil shales and their precursors. This article represents an introductory overview of the literature of the last 25 years pertaining to geochemical pyrolysis studies. The overview introduces non-geochemists to the many areas in academic and industrial geochemistry to which pyrolysis in general, and analytical pyrolysis in particular, are applicable. 127 references.

Larter, S.R. (Union Oil Science and Tech. Div., Brea, CA); Douglas, A.G.

1982-06-01

309

Development of a high-performance coal-fired power generating system with pyrolysis gas and char-fired high-temperature furnace (HITAF): Volume 3. Final report  

Energy Technology Data Exchange (ETDEWEB)

Testing of an atmospheric circulating bed pyrolyzer was done at Southern Illinois University. A variety of experiments have been conducted in a laboratory scale pyrolyzer with coal input flow rates from 2 to 6 lb/h. three feed coal particle sizes, corresponding to a nominal -40 mesh, -30 mesh and -18 mesh were used. The limestone used in the tests was a Genstar limestone. Parameters investigated in the tests include the influence of superficial velocity, temperature and coal-air mass ratios. Char particle size distributions under various test conditions have been measured and the char composition determined. Fuel gas composition, yields and heating values have been investigated. Char morphology has been studied using scanning electron microscopy. Char reactivity for selected samples has been measures, and the influence of feed coal size, bed temperature and superficial velocity has been determined. Material balance calculations have been performed and found to be in very good agreement. Energy audit calculations for the process have been made to investigate the flow of energy and to estimate the losses during the process. Full details of the data, results obtained and conclusions drawn are presented.

NONE

1996-05-01

310

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

311

Silane neutral chemistry in discharges and pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Photovoltaic devices made with amorphous silicon thin films are emerging as an important energy technology. Progress on making efficient devices and understanding the material properties has resulted from research done in the last ten years, while the understanding of the deposition process has seen less progress until recently. Results on two deposition processes are reported here: for dc discharges where electrical energy is used to initiate the chemical reactions that cause deposition, and for pyrolysis where thermal energy is utilized. The dc discharges in low pressures of silane or silane-inert gas mixtures were studied by mass spectrometer observations of stable and radical gas species at varying discharge conditions. A threshold ionization technique was used that allowed the radicals to be observed with high sensitivity. The pyrolysis of silane was studied first through pressure change rates in a static-gas vessel at pressures and temperatures typically used to make amorphous silicon films. Two mass spectrometer experiments (a flowing-gas oven and a filament experiment) were then done under conditions of low pressure and higher temperature to verify the results from the static vessel.

Robertson, R.M.

1986-01-01

312

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

313

Examination of sulfur forms in coal by direct pyrolysis and flameless ozone-sulfur chemiluminescence detection  

Energy Technology Data Exchange (ETDEWEB)

The extremely high selectivity of the newly developed ozone-sulfur chemiluminescence detector (SCD) has been coupled with controlled-temperature pyrolysis to allow qualitative and semiquantitative determination of sulfur forms in coal. Pyrolysis products from the heating of a sulfur containing solid sample were swept directly through a high-temperature conversion tube and into the SCD to yield a strong signal. Upon heating the pyrolysis tube from room temperature to 700 degrees C, several distinct peaks were observed by the SCD, identified as being due to aliphatic sulfides and thiols, elemental sulfur, simple thiophenes, pyrite, and complex thiophenes. Standard addition of the pure inorganic substances provided semiquantitative determinations. Three coals were examined and could be quickly and easily distinguished by their sulfur forms. The results are compared with those of other pyrolysis methods.

Glinski, R.J.; Xu, Xiaoyang; McGowan, C.W. [Tennessee Technological Univ., Cookeville, TN (United States)

1995-12-31

314

Bio-Fuel Production Assisted with High Temperature Steam Electrolysis  

Energy Technology Data Exchange (ETDEWEB)

Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oil and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier.

Grant Hawkes; James O' Brien; Michael McKellar

2012-06-01

315

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

UK PubMed Central (United Kingdom)

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 650°C via catalytic pyrolysis (1% of Z-N catalyst) and at 650 and 730°C 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 730°C while via catalytic pyrolysis were: 6.5/89.0/4.5%wt. and 54.3/41.9/3.8%wt. at 500 and 650°C, respectively. At 650°C 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.

Donaj PJ; Kaminsky W; Buzeto F; Yang W

2012-05-01

316

Deoxygenation of hydroquinones as a general route to norbornane-fused aromatic systems: an entry into substituted and functionalized dimethano- and methanoanthracenes.  

Science.gov (United States)

A high-yielding route to substituted and functionalized dimethanoanthracenes by the Pd-catalyzed deoxyenation of the corresponding hydroquinone precursors is described. Attempts were made to deoxygenate the 9,10-dimesylate, ditosylate, and ditriflate derivatives of anti-dimethanoanthracene 1a, and it was found that under the studied conditions only the ditriflate 8a gave the corresponding deoxygenated aromatic scaffold. Optimization of the reaction conditions identified the Pd(OAc)(2)/dppf tandem as a suitable catalytic system for this transformation. The presented strategy was further extended to a novel and efficient synthetic route to methanoanthracenes employing a one-pot Pd-catalyzed deoxygenation/hydrogenation sequence. PMID:22136284

Ganji, Prasad; Ibrahim, Hasim

2011-12-20

317

Deoxygenation of hydroquinones as a general route to norbornane-fused aromatic systems: an entry into substituted and functionalized dimethano- and methanoanthracenes.  

UK PubMed Central (United Kingdom)

A high-yielding route to substituted and functionalized dimethanoanthracenes by the Pd-catalyzed deoxyenation of the corresponding hydroquinone precursors is described. Attempts were made to deoxygenate the 9,10-dimesylate, ditosylate, and ditriflate derivatives of anti-dimethanoanthracene 1a, and it was found that under the studied conditions only the ditriflate 8a gave the corresponding deoxygenated aromatic scaffold. Optimization of the reaction conditions identified the Pd(OAc)(2)/dppf tandem as a suitable catalytic system for this transformation. The presented strategy was further extended to a novel and efficient synthetic route to methanoanthracenes employing a one-pot Pd-catalyzed deoxygenation/hydrogenation sequence.

Ganji P; Ibrahim H

2012-01-01

318

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)

2005-01-01

319

Pyrolysis and combustion studies of polymers by gas chromatography and thermal analysis  

Energy Technology Data Exchange (ETDEWEB)

The aim of this thesis is to give an overview of the combustion and pyrolysis of the most common polymers and to test and develop methods, including computerized chromatography and multivariate data analysis. The special role of pyrolysis in the burning of polymers is emphasized in a review which forms the first part of the thesis. The fuel in flaming combustion of polymers is generally a complex mixture of pyrolysis products which makes it very complicated to study the burning on the level of elementary reactions. Thermochromatography (ThCG), in other words temperature resolved pyrolysis coupled with gas chromatographic analysis of evolving gases, is used in the experimental part of this work. Several examples of ThGC analysis are given. It is shown how thermograms similar to differential TG can be gained by principal factor analysis of the ThGC data. In addition the evolving of a variety of products can be measured against the pyrolysis temperature. The submitted five papers contain thermoanalytical and gas chromatographic studies of polymer pyrolysis and combustion. The usefulness of computerized chromatography and multivariate data analysis is shown in these cases which include a method of comparing the chromatographic fingerprints of combustion products, stroboscopic sampling to gas chromatograph to study rapid oxidation processes, thermogravimetric analysis of rubber blends and correlation chromatography of the initial stage of a pyrolysis. Also polycyclic aromatic hydrocarbons (PAH) produced in the combustion of polystyrene, polypropylene and wood are analyzed to gain a better understanding of the hazards of burning plastics.

Elomaa, M. (Helsinki Univ. (Finland). Dept. of Polymer Chemistry)

1991-01-01

320

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

 
 
 
 
321

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. Sánchez-García; Arturo Maldonado; Luis Castañeda; Rutilo Silva-González; María de la Luz Olvera

2012-01-01

322

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)

[en] 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

1995-01-01

323

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, evaluating the economic and technical feasibility of the concept, and preparing an R D plan to develop the concept further. The power generating system being developed in this project will be an improvement over current coal-fired systems. Goals have been specified that relate to the efficiency, emissions, costs, and general operation of the system. 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 coal-derived fuels and then directly heated in a natural-gas-fired combustor 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 fuel gas is relatively clean, 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 to be 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.

1993-02-01

324

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)

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 coal-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 fuel gas 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 to be 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. Bechtel investigated different cycle analysis programs, and one was selected for use on this project. The program was then run for different pyrolyzer conditions, steam conditions, and gas turbine blade cooling airflow. This information yielded trends that were used to develop preliminary cycle parameters. Next, all team members estimated the range of significant operating parameters and capacities for their equipment. Bechtel then determined a plant size and equipment arrangement that would be reasonable for the commercial plant design. The cycle analysis, plant size, and equipment arrangement developed in this subtask will serve as a starting point for the subsystem and component R D. After the subsystem R D and the necessary trade-off studies have been completed, the cycle analysis and plant arrangement will be re-evaluated.

1992-07-01

325

Kinetic study on hydrocarbon forming pyrolysis of Fushun and Maoming oil shales  

Energy Technology Data Exchange (ETDEWEB)

The Rock Eval apparatus for studying hydrocarbon-forming kinetics of oil shales is used on four Chinese oil shale samples. Under experimental conditions, the main stage of hydrocarbon formation during pyrolysis may be treated as an overall first order kinetic model. The experimental data are well fitted with the kinetic equations obtained with calculated apparent activation energy and frequency factor. The time required for pyrolysis under constant temperature are also calculated. The results may be used for the design of the pyrolysis retort, especially for fine particles of oil shales.

Wang, J.Q.; Qian, J.L.; Wu, L.Y.

1984-01-01

326

Pyrolysis of brown coal mixed with heavy products of coal and petroleum processing  

Energy Technology Data Exchange (ETDEWEB)

Investigates effect of various additives on yield of liquid product from pyrolysis of Kansk-Achinsk (Berezovsk deposit) brown coal mixed with organic additives: waste from caprolactam plant consisting mostly of saturated oxygen containing compounds and mono- and di-carboxylic acid esters, waste from sabatic acid plant consisting predominantly of unsaturated acids, distillation residue of synthetic fatty acids, heavy residue from Arlansk oil refineries containing mainly condensed naphtheno-aromatic systems and heavy tar from rapid pyrolysis of Kansk-Achinsk coal. Finds that joint pyrolysis of brown coal with organic additives increases yield of liquid products and that intensive decomposition begins at lower temperatures. 4 refs.

Vikhorev, A.A.; Syroezhko, A.M.; Proskuryakov, V.A.; Akhmedov, N.A.

1987-03-01

327

Bio-oil from pyrolysis of cashew nut shell - a near fuel  

Energy Technology Data Exchange (ETDEWEB)

Cashew nut shell (CNS) has been studied for the product distribution in a packed bed vacuum pyrolysis unit. The effect of pyrolysis temperatures on the product yields is also studied. The oil-to-liquid ratio in the pyrolysis products was found to remain almost constant in the range between 400{sup o}C and 550{sup o}C. The properties of CNS oil has been found to be amazingly near to that of petroleum fuels with calorific value as high as 40 MJkg{sup -1}, the oil has a low ash content (0.01%) and water content is limited to 3-3.5 wt% of oil. (Author)

Das, P.; Ganesh, A. [Indian Inst. of technology, Mumbai (India). Energy Systems Engineering

2003-07-01

328

Mineral matter effects in rapid pyrolysis of beech wood  

Energy Technology Data Exchange (ETDEWEB)

The effects of cations on the yields of char, tar, light oils, and total gases from rapid pyrolysis of beech wood were studied. Raw wood, acid washed wood, and wood impregnated with potassium, sodium, and calcium cations were pyrolyzed in 1 atm pressure of helium at 1000{degree}C s{sup -1} heating rate to a peak temperature of {approx} 1000{degree}C. Experiments were carried out in an electrical screen heater reactor, and the yields of products were determined as a function of pyrolysis peak temperature. Acid washed wood samples gave the highest tar yield (about 61% by weight of the original wood), whereas wood samples impregnated with potassium or sodium cations gave the lowest yield of tar (32 wt%). The char yield from acid washed wood samples was lower (about 6 wt%), and it was higher for raw wood and for wood samples impregnated with different cations (10-15%). The maximum gas yield was lower at {approx} 34 wt% for acid washed wood and much higher ({approx} 58 wt%) for the wood samples impregnated with potassium and sodium cations. These results confirm the marked catalytic effects of cations on the post-pyrolysis cracking reactions of tar (the major product of wood pyrolysis) and the formation of char and gaseous products via cracking reactions of tar. In all cases, sodium and potassium cations showed a stronger effect than calcium cations. The tar molecular weight was measured for wood samples impregnated with different cations. Tar molecular weight decreased with addition of cations to the wood particles, whereas it remained relatively constant with pyrolysis temperature. 20 refs., 9 figs., 2 tabs.

Nik-Azar, M.; Hajaligol, M.R.; Sohrabi, M.; Dabir, B. [Amir-Kabir University of Technology, Teheran (Iran). Dept. of Chemical Engineering

1997-03-01

329

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products  

Energy Technology Data Exchange (ETDEWEB)

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

330

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products  

Energy Technology Data Exchange (ETDEWEB)

A process is described for 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. 87 figures.

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

1994-04-05

331

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products  

Energy Technology Data Exchange (ETDEWEB)

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)

1994-01-01

332

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products  

Energy Technology Data Exchange (ETDEWEB)

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)

1994-01-01

333

Controlled catalytic and thermal sequential pyrolysis and hydrolysis of mixed polymer waste streams to sequentially recover monomers or other high value products  

Energy Technology Data Exchange (ETDEWEB)

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)

1993-01-01

334

Study on the combined sewage sludge pyrolysis and gasification process: mass and energy balance.  

Science.gov (United States)

A combined pyrolysis and gasification process for sewage sludge was studied in this paper for the purpose of its safe disposal with energy self-balance. Three sewage sludge samples with different dry basis lower heat values (LHV(db)) were used to evaluate the constraints on this combined process. Those samples were pre-dried and then pyrolysed within the temperature range of 400-550 degrees C. Afterwards, the char obtained from pyrolysis was gasified to produce fuel gas. The experimental results showed that the char yield ranged between 37.28 and 53.75 wt% of the dry sludge and it changed with ash content, pyrolysis temperature and LHV(db) of the sewage sludge. The gas from char gasification had a LHV around 5.31-5.65 MJ/Nm3, suggesting it can be utilized to supply energy in the sewage sludge drying and pyrolysis process. It was also found that energy balance in the combined process was affected by the LHV(db) of sewage sludge, moisture content and pyrolysis temperature. Higher LHV(db), lower moisture content and higher pyrolysis temperature benefit energy self-balance. For sewage sludge with a moisture content of 80 wt%, LHV(db) of sewage sludge should be higher than 18 MJ/kg and the pyrolysis temperature should be higher than 450 degrees C to maintain energy self-sufficiency when volatile from the pyrolysis process is the only energy supplier; when the LHV(db) was in the range of 14.65-18 MJ/kg, energy self-balance could be maintained in this combined process with fuel gas from char gasification as a supplementary fuel; auxiliary fuel was always needed if the LHV(db) was lower than 14.65 MJ/kg. PMID:23437644

Wang, Zhonghui; Chen, Dezhen; Song, Xueding; Zhao, Lei

2012-12-01

335

Study on the combined sewage sludge pyrolysis and gasification process: mass and energy balance.  

UK PubMed Central (United Kingdom)

A combined pyrolysis and gasification process for sewage sludge was studied in this paper for the purpose of its safe disposal with energy self-balance. Three sewage sludge samples with different dry basis lower heat values (LHV(db)) were used to evaluate the constraints on this combined process. Those samples were pre-dried and then pyrolysed within the temperature range of 400-550 degrees C. Afterwards, the char obtained from pyrolysis was gasified to produce fuel gas. The experimental results showed that the char yield ranged between 37.28 and 53.75 wt% of the dry sludge and it changed with ash content, pyrolysis temperature and LHV(db) of the sewage sludge. The gas from char gasification had a LHV around 5.31-5.65 MJ/Nm3, suggesting it can be utilized to supply energy in the sewage sludge drying and pyrolysis process. It was also found that energy balance in the combined process was affected by the LHV(db) of sewage sludge, moisture content and pyrolysis temperature. Higher LHV(db), lower moisture content and higher pyrolysis temperature benefit energy self-balance. For sewage sludge with a moisture content of 80 wt%, LHV(db) of sewage sludge should be higher than 18 MJ/kg and the pyrolysis temperature should be higher than 450 degrees C to maintain energy self-sufficiency when volatile from the pyrolysis process is the only energy supplier; when the LHV(db) was in the range of 14.65-18 MJ/kg, energy self-balance could be maintained in this combined process with fuel gas from char gasification as a supplementary fuel; auxiliary fuel was always needed if the LHV(db) was lower than 14.65 MJ/kg.

Wang Z; Chen D; Song X; Zhao L

2012-12-01

336

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

337

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 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)

2009-01-01

338

Gas product distribution from polyethylene pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The disposal of plastic waste is extensively studied nowadays. Of the treatments available, thermal degradation is attracting great interest because it offers the possibility of recovering energy and useful chemicals. PE pyrolysis has already been discussed in a previous paper where the rate of decomposition of a sample was modeled using a detailed kinetic scheme. Its predictions were validated by thermogravimetric experimental results across wide operative pressure and heating rate ranges. The gas product distribution was derived from the random scission hypothesis. Thus, the ratio of alkane, alkene and dialkene species was 1:2:1 and, within the same class of products, the distribution was equimolecular, except for those species which are more favored by allyl resonance. This paper aims to continue the previous work in attempting to model gas products correctly. The principal improvements made here are the introduction of backbiting reactions into the kinetic scheme to predict the larger amounts of selected products and the consideration of the physical aspects of the degradation process. These phenomena are responsible for the production rate and the distribution of volatiles. A simplified model of the in-depth mass transfer through bubble formation is presented which describes the degradation progress for a small-sized polyethylene sample. The model predictions are compared with both the experimental results of polyethylene pyrolysis performed under various temperature conditions and with thermogravimetric analysis

Faravelli, T.; Bozzano, G.; Scassa, C.; Perego, M.; Fabini, S.; Ranzi, E.; Dente, M. [CIIC Dipartimento di Chimica Industriale e Ingegneria Chimica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milan (Italy)

1999-09-01

339

A device for automatically controlling the pyrolysis of benzene and ethane in a tube furnace  

Energy Technology Data Exchange (ETDEWEB)

A device for automatically controlling the pyrolysis of benzene and ethane in a tube furnace, which contains a coil pipe for heating the benzene, and which subjects ethane only to the initial pyrolysis and the joint pyrolysis of benzene and ethane, consists of a sequentially linked sensor and pyrolysis temperature regulator at the furnace outlet and a valve in the fuel injection line into the furnace, a benzene flow meter for the furnace which is connected to the first inlet of the pyrolysis temperature programmer at the furnace outlet, this outlet is connected to the second inlet of the temperature regulator and a pyrogas composition sensor which is connected to the valve in the fuel flow line. The device is improved in order to increase the furnace's productivity. The device includes other sensors which are connected to each other, the regulators and the furnace. The proposed device makes it possible to regulate the temperature at the furnace outlet; that determines the possibility of changing the composition of pyrogas relative to the conjunctive situation and the optimum conversion of ethane in the coil pipe for the initial pyrolysis when the heating resources of the furnace are being fully used. The production of the major marketable products by incorporating the proposed method is increased on the average by five relative percentage points.

Anashkin, S.G.; Kazyupa, Yu.N.; Kuritsyn, V.A.; Rodhykh, Yu.V.; Skliarov, B.M.; Slipchenko, A.A.; Tuchinskii, M.R.; Vetrov, P.I.

1982-01-01

340

Comparison of hydrous pyrolysis products from organic-rich sediments and biomass  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis experiments have been conducted on oil shale, lignite, and biomass, in a 100 mL stainless-steel cylindrical reactor at 725, 825, 925, and 1025 K isothermally. The pyrolysis product distribution is strongly dependent on reactor geometry, temperature, heating rate, residence time, mass transfer velocity, and pressure. Temperature and water-to-sample ratio were pyrolysis parameters. The yield of tarry materials of Goynuk oil shale and Yotagan lignite increased from 23.1 to 29.8% and 13.7 to 21.8%, respectively, while the final pyrolysis temperature was increased from 725 to 1025 K. The yield of gaseous products of Goynuk oil shale, Yotagan lignite, and solid waste increased from 8.6 to 14.9%, 6.7 to 16.1%, and 23.5 to 37.0%, respectively, while the final pyrolysis temperature was increased from 725 to 1025 K. The yield of tarry materials of Goynuk oil shale and Yatagan lignite increased from 21.45 to 37.5% and 11.7 to 25.8%, respectively, while the final pyrolysis water-to-sample ratio was increased from 1:1 to 5:1 at 825 K.

Demirbas, A.

2002-09-01

 
 
 
 
341

Bio-oil production from fast pyrolysis of waste furniture sawdust in a fluidized bed.  

UK PubMed Central (United Kingdom)

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.

Heo HS; Park HJ; Park YK; Ryu C; Suh DJ; Suh YW; Yim JH; Kim SS

2010-01-01

342

Process design and simulation of H2-rich gases production from biomass pyrolysis process.  

UK PubMed Central (United Kingdom)

In this study, biomass pyrolysis process for producing H(2)-rich gas is presented. The whole biomass pyrolysis process is established and simulated based on rigorous thermodynamic model, which includes pyrolysis reactor connecting one oil cracking reactor, water gas reactor and a gasifier. The simulation results are verified by the laboratory scale experimental measurements. Then, the influence of main operation parameters such as seam/biomass ratio, temperature (pyrolysis reactor, oil thermal cracking and gasifier) on the composition of fuel gas and hydrogen yield is discussed. Lastly, the optimization results are available. The results indicate that higher gas products and hydrogen yield can be obtained from the process, the H(2) yield can reach 83g/kg biomass, the H(2) concentration can reach 55% (mol) at the optimal temperature and steam/biomass ratio.

Li C; Suzuki K

2010-01-01

343

Pyrolysis of Turkish Zonguldak bituminous coal. Part 1. Effect of mineral matter  

Energy Technology Data Exchange (ETDEWEB)

The effects of mineral matter on the conversion of organic material in low temperature pyrolysis (300-500{degree}C) of the vitrinite-rich Zonguldak bituminous coal and acid-washed coals were investigated. Calcium, iron and magnesium cations were removed from coal with HCl washing. The results indicated that these cations had catalytic effects during pyrolysis. It was also observed that the conversion in the pyrolysis process was increased with the removal of the illite, kaolinite, chlorine and quartz minerals. The volumetric swelling ratios of the chars obtained in different experimental conditions were measured using the pyridine swelling technique and the extent of cross-linking in the macromolecular network of chars was examined. It was found that the cross-linking increased as the pyrolysis temperature was increased from 300 to 500{degree}C. 35 refs., 8 figs., 2 tabs.

Oztas, N.A.; Yurum, Y. [Hacettepe University, Ankara (Turkey). Dept. of Chemistry

2000-08-01

344

Fast pyrolysis of sunflower-pressed bagasse: effects of sweeping gas flow rate  

Energy Technology Data Exchange (ETDEWEB)

Sunflower (Helianthus annus L.)-pressed bagasse pyrolysis experiments were performed in a fixed-bed tubular reactor. The effects of nitrogen flow rate and final pyrolysis temperature on the pyrolysis product yields and chemical compositions have been investigated. The maximum bio-oil yield of 52.85 wt% was obtained in a nitrogen atmosphere and a nitrogen flow rate of 50 cm{sup 3} min{sup -1} and at a pyrolysis temperature of 550{sup o}C and heating rate of 5{sup o}C s{sup -1}. The chemical characterization has shown that the oil obtained from sunflower-pressed bagasse may be potentially valuable as fuel and chemical feedstocks. (author)

Gercel, H.F.; Putun, E.

2002-05-01

345

Production and characterization of pyrolysis liquids from sunflower-pressed bagasse  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis experiments on sunflower (Helianthus annus L.)-pressed bagasse were performed in a fixed-bed tubular reactor. The effects of nitrogen flow rate and final pyrolysis temperature on the pyrolysis product yields and chemical compositions were investigated. The maximum bio-oil yield of 52.10 wt.% was obtained in a nitrogen atmosphere with flow rate of 50 ml min{sup -1} and at a pyrolysis temperature of 550{sup o}C with a heating rate of 5{sup o}C s{sup -1}. The chemical characterization results showed that the oil obtained from sunflower-pressed bagasse may be a potentially valuable source as fuel or chemical feedstocks. (author)

Gercel, H.F. [Anadolu University (Turkey). Dept. of Chemical Engineering

2002-11-01

346

The production and evaluation of bio-oils from the pyrolysis of sunflower-oil cake  

Energy Technology Data Exchange (ETDEWEB)

Sunflower (Helianthus annus L.)-oil cake pyrolysis experiments were achieved in a fixed-bed tubular reactor. The effects of nitrogen flow rate and final pyrolysis temperature on the pyrolysis product yields and chemical compositions have been investigated. The maximum bio-oil yield of 48.69 wt% was obtained in nitrogen atmosphere with nitrogen flow rate of 100 cm{sup 3} min{sup -1} and at a pyrolysis temperature of 550 deg C with a heating rate of 5 deg Cs{sup -1}. Chromatographic and spectroscopic studies on the pyrolytic oil showed that the oil obtained from sunflower-oil cake can be used as a renewable fuel and chemical feedstocks. (Author)

Gercel, Hasan Ferdi [Anadolu Univ., Dept. of Chemical Engineering, Eskisehir (Turkey)

2002-10-01

347

Vacuum pyrolysis of used tires  

Energy Technology Data Exchange (ETDEWEB)

The vacuum pyrolysis of used tires enables the recovery of useful products, such as pyrolytic oil and pyrolytic carbon black (CB{sub P}). The light part of the pyrolytic oil contains dl-limonene which has a high price on the market. The naphtha fraction can be used as a high octane number component for gasoline. The middle distillate demonstrated mechanical and lubricating properties similar to those of the commercial aromatic oil Dutrex R 729. The heavy oil was tested as a feedstock for the production of needle coke. It was found that the surface morphology of CB{sub P} produced by vacuum pyrolysis resembles that of commercial carbon black. The CB{sub P} contains a higher concentration of inorganic compounds (especially ZnO and S) than commercial carbon black. The pyrolysis process feasibility looks promising. One old tire can generate upon vacuum pyrolysis, incomes of at least $2.25 US with a potential of up to $4.83 US/tire upon further product improvement. The process has been licensed to McDermott Marketing Servicing Inc. (Houston) for its exploitation in the US.

Roy, C.; Darmstadt, H.; Benallal, B.; Chaala, A.; Schwerdtfeger, A.E. [Univ. Laval, Quebec City, Quebec (Canada). Dept. de Geneie Chimique

1995-11-01

348

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.  

Science.gov (United States)

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low values. When impurities were involved, the shape of BR curves showed that intense decomposition started earlier but morphological characteristics remained the same. In addition, compared to parameters such as pressure, the BR reflects reaction stages better and its change with pyrolysis process of PE/PP plastics with or without impurities was more intrinsically process correlated; therefore it can be adopted as a signal for pyrolysis process characterization, as well as offering guide to process improvement and reactor design. PMID:23177018

Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

2012-11-22

349

Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.  

UK PubMed Central (United Kingdom)

In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low values. When impurities were involved, the shape of BR curves showed that intense decomposition started earlier but morphological characteristics remained the same. In addition, compared to parameters such as pressure, the BR reflects reaction stages better and its change with pyrolysis process of PE/PP plastics with or without impurities was more intrinsically process correlated; therefore it can be adopted as a signal for pyrolysis process characterization, as well as offering guide to process improvement and reactor design.

Wang H; Chen D; Yuan G; Ma X; Dai X

2013-02-01

350

Pyrolysis of petroleum residues: 1. Yields and product analyses  

Energy Technology Data Exchange (ETDEWEB)

This study examines the pyrolysis of three petroleum pitch residues of different aromaticities, (R1), (R2) and (R3), varying the experimental parameters of pressure, temperature and soak time. The overall objective is to provide further detailed information of factors which influence formation of anisotropy or mesophase in resultant semicokes. Pressure was varied during the progress of a pyrolysis. Yields of gases, liquids and semicokes were obtained. Gases were analysed by gas chromatography, the liquids by simulated distillation and {sup 1}H-NMR, and the semicokes by elemental analysis and FTIR. For the semicokes from Rl, yields are dominantly a function of pressure, with little influence of temperature and soak time. For semicokes from R2, yields are dominantly a function of pressure and temperature, with little influence of soak time. For semicokes from R3, yields are dominantly a function of temperature and soak time, with little influence of pressure. The use of simulated distillation and pressure release, at reaction temperatures, provides additional information about mechanisms of the pyrolysis reactions. (author)

Martinez-Escandell, M.; Torregrosa, P.; Marsh, H.; Rodriguez-Reinoso, F. [Universidad de Alicante (Spain). Dept. de Quimica Inorganica; Santamaria-Ramirez, R. [Instituto Nacional del Carbon, Oviedo (Spain); Gomez-De-Salazar, C.; Romero-Palazon, E. [REPSOL-PETROLEO, Centro de Investigacion de Cartagena (Spain)

1999-07-01

351

An experimental and modeling investigation of particle production by spray pyrolysis using a laminar flow aerosol reactor  

International Nuclear Information System (INIS)

[en] The influence of operating parameters on the morphology of particles prepared by spray pyrolysis was investigated using a temperature-graded laminar flow aerosol reactor. Experimentally, zirconia particles were prepared by spray pyrolysis using an aqueous solution of zirconyl hydroxide chloride. Hollow particles were formed if the reactor temperature was high, the temperature gradient was too large, the flow rate of carrier gas was high, and the initial solute concentration was low. A numerical simulation of the pyrolysis process was developed using a combination of two previous models. The simulation results compared well with the experimental results. (c) 2000 Materials Research Society

2000-01-01

352

An experimental and modeling investigation of particle production by spray pyrolysis using a laminar flow aerosol reactor  

Energy Technology Data Exchange (ETDEWEB)

The influence of operating parameters on the morphology of particles prepared by spray pyrolysis was investigated using a temperature-graded laminar flow aerosol reactor. Experimentally, zirconia particles were prepared by spray pyrolysis using an aqueous solution of zirconyl hydroxide chloride. Hollow particles were formed if the reactor temperature was high, the temperature gradient was too large, the flow rate of carrier gas was high, and the initial solute concentration was low. A numerical simulation of the pyrolysis process was developed using a combination of two previous models. The simulation results compared well with the experimental results. (c) 2000 Materials Research Society.

Lenggoro, I. Wuled [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan); Hata, Takeshi [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan); Iskandar, Ferry [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan); Lunden, Melissa M. [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Okuyama, Kikuo [Department of Chemical Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527 Japan (Japan)

2000-03-01

353

Mild pyrolysis of selectively oxidized coals. Technical report, September 1--November 30, 1991  

Energy Technology Data Exchange (ETDEWEB)

The primary objective of this study is to investigate the removal organic sulfur from selectively oxidized Illinois coals using mild thermal/chemical processes. Work completed this quarter includes the investigation of the mild pyrolysis of unoxidized coals plus a selection of selectively oxidized coals. In addition the effect of particle size and extent of oxidation on pyrolysis was investigated. Some preliminary data concerning pyrolysis under vacuum and ambient pressure was also obtained. Work completed this quarter supports the following conclusions: (1) Desulfurization of unoxidized coals increases with increasing pyrolysis temperature and correlates with the loss of volatile matter. (2) Particle size did not influence the extent of desulfurization significantly. (3) Removing pyrite prior to pyrolysis helps to achieve a lower sulfur product beyond that expected from the removal of pyrite alone. (4) The extent of selective oxidation in teh pretreatment step did not effect the level of desulfurization obtained by pyrolysis alone. However this factor was important in the desulfurization obtained with supercritical methanol (SCM)/base. (5) Up to 84% of the sulfur has been removed from the IBC 101 coal by combining selective oxidation and SCM/base reactions. (6) Evidence for regressive reactions between volatilized sulfur compounds and partially desulfurized products was obtained by studying how changes in pyrolysis pressure effected the product sulfur content.

Hippo, E.J.

1991-12-31

354

Pyrolysis kinetics and decomposition characteristics of pine trees.  

UK PubMed Central (United Kingdom)

Pine trees comprise over 35% of the forests in Korea, since 1989, pine wilt disease introduced via the Japanese pine sawyer has been infecting many of these trees. As a renewable resource, pine can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics of pine trees were investigated using thermogravimetric analyzer, with most of the materials decomposing between 330 and 370 degrees C at heating rates of 5-20 degrees C/min. The apparent activation energy increased from 145 to 302 kJ mol(-1) with increasing pyrolysis conversion. The kinetics of pine tree pyrolysis were experimentally and mathematically evaluated. The kinetic parameters were determined using nonlinear least-squares regression of the experimental data assuming first-order kinetics. It was found from the kinetic rate constants that the predominant reaction pathway was A (pine) to gas (C(1)-C(4)) rather than A to bio-oil at temperatures of 330-370 degrees C.

Kim SS; Kim J; Park YH; Park YK

2010-12-01

355

Pyrolysis kinetics and decomposition characteristics of pine trees.  

Science.gov (United States)

Pine trees comprise over 35% of the forests in Korea, since 1989, pine wilt disease introduced via the Japanese pine sawyer has been infecting many of these trees. As a renewable resource, pine can be converted to bio-oil, gas, and char through pyrolysis. In this study, the pyrolysis characteristics of pine trees were investigated using thermogravimetric analyzer, with most of the materials decomposing between 330 and 370 degrees C at heating rates of 5-20 degrees C/min. The apparent activation energy increased from 145 to 302 kJ mol(-1) with increasing pyrolysis conversion. The kinetics of pine tree pyrolysis were experimentally and mathematically evaluated. The kinetic parameters were determined using nonlinear least-squares regression of the experimental data assuming first-order kinetics. It was found from the kinetic rate constants that the predominant reaction pathway was A (pine) to gas (C(1)-C(4)) rather than A to bio-oil at temperatures of 330-370 degrees C. PMID:20709530

Kim, Seung-Soo; Kim, Jinsoo; Park, Young-Hun; Park, Young-Kwon

2010-07-29

356

Fixed bed pyrolysis of Euphorbia rigida with different catalysts  

International Nuclear Information System (INIS)

Since Euphorbia rigida is a celluloid plant with low fat content, the oil yields of previous fixed bed pyrolysis studies were low. In order to increase the oil yield, biomass pyrolysis experiments were performed in a fixed bed reactor with two selected commercial catalysts, namely Criterion-534 and activated alumina, and natural zeolite (klinoptilolite). Experiments were conducted in a static atmosphere with a heating rate of 7 deg. C min-1, pyrolysis temperature of 550 deg. C and mean particle size of 0.55 mm. In the experiments, all the catalysts were used with various percentages, and the effects of the variable catalysts on the yields and chemical composition of the oils obtained were investigated. Oil yield reached 27.5% with the use of natural zeolite, 31% with Criterion-534 and 28.1% with activated alumina, while it was only 21.6% without a catalyst. The pyrolysis oils were examined by using spectroscopic and chromatographic analysis techniques, and the obtained results were compared with the results of similar experiments achieved without a catalyst.

2005-01-01

357

Fixed bed pyrolysis of Euphorbia rigida with different catalysts  

Energy Technology Data Exchange (ETDEWEB)

Since Euphorbia rigida is a celluloid plant with low fat content, the oil yields of previous fixed bed pyrolysis studies were low. In order to increase the oil yield, biomass pyrolysis experiments were performed in a fixed bed reactor with two selected commercial catalysts, namely Criterion-534 and activated alumina, and natural zeolite (klinoptilolite). Experiments were conducted in a static atmosphere with a heating rate of 7{sup o}C min{sup -1}, pyrolysis temperature of 550{sup o}C and mean particle size of 0.55 mm. In the experiments, all the catalysts were used with various percentages, and the effects of the variable catalysts on the yields and chemical composition of the oils obtained were investigated. Oil yield reached 27.5% with the use of natural zeolite, 31% with Criterion-534 and 28.1% with activated alumina, while it was only 21.6% without a catalyst. The pyrolysis oils were examined by using spectroscopic and chromatographic analysis techniques, and the obtained results were compared with the results of similar experiments achieved without a catalyst. (author)

Funda Ates; Putun, A.E. [Anadolu University, Eskisehir (Turkey). Dept. of Chemical Engineering; Ersan Putun [Anadolu University, Eskisehir (Turkey). Dept. of Material Science and Engineering

2005-02-01

358

Fixed bed pyrolysis of Euphorbia rigida with different catalysts  

Energy Technology Data Exchange (ETDEWEB)

Since Euphorbia rigida is a celluloid plant with low fat content, the oil yields of previous fixed bed pyrolysis studies were low. In order to increase the oil yield, biomass pyrolysis experiments were performed in a fixed bed reactor with two selected commercial catalysts, namely Criterion-534 and activated alumina, and natural zeolite (klinoptilolite). Experiments were conducted in a static atmosphere with a heating rate of 7 deg. C min{sup -1}, pyrolysis temperature of 550 deg. C and mean particle size of 0.55 mm. In the experiments, all the catalysts were used with various percentages, and the effects of the variable catalysts on the yields and chemical composition of the oils obtained were investigated. Oil yield reached 27.5% with the use of natural zeolite, 31% with Criterion-534 and 28.1% with activated alumina, while it was only 21.6% without a catalyst. The pyrolysis oils were examined by using spectroscopic and chromatographic analysis techniques, and the obtained results were compared with the results of similar experiments achieved without a catalyst.

Ates, Funda; Puetuen, Ayse E.; Puetuen, Ersan E-mail: eputun@anadolu.edu.tr

2005-02-01

359

Fate of forms of arsenic in Yima coal during pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Forms of arsenic in a Chinese bituminous coal, Yima, and their transformation behaviors during coal pyrolysis were investigated. The chemical leaching method was used to characterize the forms of arsenic in the raw coal and the chars. The effect of minerals on arsenic release was also studied. It was found that about 72% arsenic in YM coal is bound to sulfide species; 16% to sulfates, phosphates, or oxides; 10% to organic species; and 2% to aluminosilicates. The organic-bound arsenic is the most releasable, while the aluminosilicates-bound arsenic is the least releasable. Aluminosilicates inhibit arsenic release due to the formation of aluminosilicates-bound arsenic during pyrolysis. Sulfides, sulfates, phosphates, or oxides may also restrain arsenic release. Carbonates and ion exchangeable minerals in Yima coal do not show any significant influence on the release of arsenic during coal pyrolysis. Secondary reactions between arsenic and the coal matrix should exist, as evidenced by significant increase in organic-bound arsenic in chars obtained from pyrolysis in a temperature range of 300-700{sup o}C. 18 refs., 5 figs., 5 tabs.

Ruiqing Liu; Jianli Yang; Yong Xiao; Zhenyu Liu [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion

2009-04-15

360

Pyrolysis of thermally thick wood particles - experiments and mathematical modelling  

Energy Technology Data Exchange (ETDEWEB)

A simple, dynamic, l-dimensional model describing heating, drying and pyrolysis of thermally thick wood particles with a l-dimensional geometry has been developed and implemented. The model output is the dynamic evolution of both the char yield and the amount of volatiles. The model is developed in such a simple and accessible way, that it easily can be implemented in a larger model for dimensioning and optimisation of applications where pyrolysis is a part of the overall process as for instance gasification. Experiments using a Thermo Gravimetric Analyser (TGA), built so pieces of wood can be fed into a hot atmosphere instantaneously, have been used to observe the influence of various parameters like temperature and size and wood types on the pyrolysis process. Results from the model have been compared with results from the experiments. The comparison showed good accordance when both wood particles with a well-defined geometry (a cylinder) and when beds of wood chips and wood pellets, respectively, were pyrolyzed. The model has proven that transport of heat to the wood; internal transport and accumulation of heat inside the wood and kinetics of pyrolysis are all important parameters. (au)

Moeller Andersen, S.; Thaaning Pedersen, S.; Goebel, B.; Houbak, N.; Henriksen, Ulrik [MEK - DTU, Kgs. Lyngby (Denmark); Dall Bentzen, J. [COWI a/s, Kgs. Lyngby (Denmark)

2005-07-01

 
 
 
 
361

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 catalyst’s 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

362

Inspiratory loading and limb locomotor and respiratory muscle deoxygenation during cycling exercise.  

UK PubMed Central (United Kingdom)

The aim of this study was to determine the effect of inspiratory loading on limb locomotor (LM) and respiratory muscle (RM) deoxygenation ([deoxy (Hb+Mb)]) using NIRS during constant-power cycling exercise. Sixteen, male cyclists completed three, 6-min trials. The intensity of the first 3-min of each trial was equivalent to ~80% V(O(2max)) (EX(80%)); during the final 3-min, subjects received an intervention consisting of either moderate inspiratory loading (Load(mod)), heavy inspiratory loading (Load(heavy)), or maximal exercise (Load(EX)). Load(heavy) significantly increased LM [deoxy(Hb+Mb)] from 12.2±9.0 ?m during EX(80%) to 15.3±11.7 ?m, and RM [deoxy(Hb+Mb)] from 5.9±3.6 ?m to 9.5±6.6 ?m. LM and RM [deoxy(Hb+Mb)] were significantly increased from EX(80%) to Load(EX); 12.8±9.1 ?m to 16.4±10.3 ?m and 5.9±2.9 ?m to 11.0±6.4 ?m, respectively. These data suggest an increase in respiratory muscle load increases muscle deoxy(Hb+Mb) and thus may indicate a reduction in oxygen delivery and/or increased oxygen extraction by the active muscles.

Turner LA; Tecklenburg-Lund S; Chapman RF; Stager JM; Duke JW; Mickleborough TD

2013-02-01

363

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.; Bég, O. Anwar; Sharma, S.; Zueco, J.

2010-05-01

364

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

365

Co-pyrolysis and Catalytic Co-pyrolysis of Waste Tyres with Oil Palm Empty Fruit Bunches  

Directory of Open Access Journals (Sweden)

Full Text Available Shredded Waste Tyres (SWT) and Shredded Oil Palm Empty Fruit Bunches (SOPEFB) were pyrolysed in a fixed bed reactor at 500C with a ratio of 1:1. SWT and impregnated SOPEFB with 10% w/w of cobalt catalyst solution were then pyrolysed in the same reactor at 500oC. The pyrolysed oils were collected in an ice/water condenser. The aim of this work is to study the effects of the addition of cobalt catalyst with direct impregnation into the SOPEFB fibers with respect to the liquid yields. The reactor was externally heated by means of electrical resistance, the heating rate being approximately 30C min-1. Once the required temperature obtained, it was maintained for 2 h. Three phases were obtained after pyrolysis : solid, liquid and gas. Highest yield of liquid product obtained with catalytic co-pyrolysis of SWT and SOPEFB as compared to co-pyrolysis of SWT and SOPEFB. It can be concluded that the catalytic co-pyrolysis using cobalt as catalyst resulted in higher of liquid yield.

R. Alias; K.H. Ku Hamid; K.N. Ismail

2011-01-01

366

Pyrolysis of waste-derived fuel mixtures containing PVC  

Energy Technology Data Exchange (ETDEWEB)

This paper describes an experimental analysis of the pyrolysis of PVC and mixtures of PVC with wood (Finnish pine) and LDPE (low density polyethylene) in nitrogen at 250-400{sup o}C. The aim is to optimise the temperature range for producing low-chlorine or chlorine-free fuel in a dehydrochlorination reactor without pyrolysing any of the other combustible fractions. Results are presented for various process temperatures for PVC, PVC/wood and PVC/LDPE mixtures. It was found that PVC tested is dehydrochlorinated at approximately 350{sup o}C and that secondary pyrolysis is suppressed when LDPE is present. Short communication. 15 refs., 5 figs., 1 tab.

Zevenhoven, R.; Axelsen, E.P.; Hupa, M. [Helsinki University of Technology, Espoo (Finland). Lab. for Energy Engineering and Environmental Protection

2002-03-01

367

PYROLYSIS KINETICS OF WASHED PRECIPITATED LIGNIN  

Directory of Open Access Journals (Sweden)

Full Text Available This article describes the pyrolysis behavior of precipitated washed lignin in a Laminar Entrained Flow Reactor between 700 and 1000°C and at different residence times. Lignin was precipitated by acidification of softwood black liquor using CO2. After acid washing, the solid material was dried and sieved (80-100 ?m). This material was then fed into the reactor at a rate of about 0.1 g/min. The formed gases were analyzed with respect to CO, CO2, and CH4, and char was collected and weighed. A traditional first order Arrhenius kinetic expression, based on the temperature of the particles with respect to residence time, was adapted to the experimental results. The activation energy was found to be 32.1 kJ/mol. The low ash content in the washed lignin gave a very low solid material residue after the reactor.

Christina Gustafsson; Tobias Richards

2009-01-01

368

Biomethanation of biomass pyrolysis gases. Final report  

Energy Technology Data Exchange (ETDEWEB)

Gasification processes have the potential to produce a synthesis gas (principally H/sub 2/, CO/sub 2/, and CO) from biomass. The advantage of such processes is all the organic components of the biomass may be converted to synthesis gas. However, this low Btu value gas is of limited use as a fuel gas. In order to convert the synthesis gas into pipeline quality methane, a methanation process is necessary. Catalytic methanation at high temperature and pressure is one such process. A potentially more economical alternative is the utilization of a biological system to carry out the conversion of biomass pyrolysis gases to methane. It was the object of this study to develop the biological methanation process and to establish conditions for maximum performance.

Tracy, C.A.; Ashare, E.

1981-08-01

369

Pyrolysis, a promising route for biomass utilization  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis of biomass is a thermal treatment which results in the production of char, liquid and gaseous products. In this laboratory the pyrolysis process has been studied experimentally using apparatus of different scales. In particular, the influence of the main process parameters on the yields and characteristics of the products has been investigated. On the basis of these results the differences between conventional and fast pyrolysis can be discussed. The most attractive product of conventional pyrolysis is charcoal, as the handling and use of bio-oil presents some problems due to its characteristics. The pyrolysis gas is a medium BTU gas and can be easily burnt. Fast pyrolysis minimizes charcoal production. This process gives as the main product a high yield of a medium BTU gas rich in hydrogen and carbon monoxide. The feasibility of the process on an industrial scale is discussed. (author).

Maschio, G. (Messina Univ. (Italy)); Koufopanos, C.; Lucchesi, A. (Pisa Univ. (Italy))

1992-01-01

370

Pyrolysis characteristics of biomass and biomass components  

Energy Technology Data Exchange (ETDEWEB)

The article reports on pyrolysis studies of biomass conducted using both a thermogravimetric analyser and a packed-bed pyrolyser. Each kind of biomass has a characteristic pyrolysis behaviour which is explained based on its individual component characteristics. Studies on isolated biomass components as well as synthetic biomass show that the interactions among the components are not of as much significance as the composition of the biomass. Direct summative correlations based on biomass component pyrolysis adequately explain both the pyrolysis characteristics and product distribution of biomass. It appears that there is no detectable interaction among the components during pyrolysis in either the thermogravimetric analyser or the packed-bed pyrolyser. However, ash present in biomass seems to have a strong influence on both the pyrolysis characteristics and the product distribution. 29 refs., 10 figs., 8 tabs.

Raveendran, K.; Ganesh, A.; Khilar, K.C. [Energy Systems Engineering, Bombay (India). Dept. of Mechanical Engineering

1996-06-01

371

Fast pyrolysis of lignin, macroalgae and sewage sludge  

DEFF Research Database (Denmark)

In the last twenty years, the fast pyrolysis process has been explored to produce bio-oil from biomass. Fast pyrolysis is a thermal conversion technology that is performed at a temperatures of 450 - 600 ºC, high biomass heating ratess (100 - 2000 K/s), a short gas residence time (less than 2 s) with no presence of oxygen. Fast pyrolysis can convert a large fraction of the biomass to bio-oil, and smaller fractions of char and gas. The pyrolysis centrifuge reactor (PCR) has been developed at the CHEC center at DTU Department of Chemical Engineering. The reactor is a compact design that uses a low flow rate of carrier gas, pyrolyse biomass without a heat carrier and obtain a biomass particle heating rate of 1000 - 1500 K/s by a high centrifugal force. The reactor can be constructed at a size that could be applicable locally at waste water treatment plants or pulp and paper plants, bio-ethanol plants or can constructed as a mobile unit of a tractor-propelled vehicle that is used on straw fields. A lot of work on PCR straw and wood pyrolysis with respect to pyrolysis conditions, moisture feedstock content, bio-oil properties, and PCR modelling is done before this PhD project. The bio-oil yields of approximately 68 and 60 wt% daf are obtained for wood and straw PCR pyrolysis, respectively and the bio-oils properties are similar to those of wood and straw pyrolysis from fluidized-bed reactors. Wood and straw, conventional biomasses, are extensively investigated and knowledge of wood and straw fast pyrolysis is available in the literature. Nonconventional biomass feedstock may also be applicable for fast pyrolysis processes. Among the forms of nonconventional 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 lignin, macroalgae and sewage sludge bio-oil properties were relatively different to those of the straw or wood bio-oils with respect to oxygen content, viscosity, HHV and mean molecular mass. 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 °C for lignin, sewage sludge and macroalgae PCR pyrolysis. Therefore the bio-oils obtained low metal concentrations (especially alkali contents less than 0.09 wt%). 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 °C. It is s

Trinh, Ngoc Trung

2013-01-01

372

Parameters for the Pyrolysis of Organic Material - Perchlorate Mixtures  

Science.gov (United States)

The ESA-lead Mars rover ExoMars (launch in 2018) will carry a suit of instruments, one of the in-struments is the Mars Organic Molecule Analyzer MOMA. Organic material in the Martian soil will be either pyrolyzed at temperatures of up to 1000°C and separated by gas chromatography or volatilized with the help of an UV-laser. A mass spectrometer will be the detector for both methods. Chlorinated organics have been detected in pyroly-sis GC-MS experiments on Mars two times. The first time during the Viking mission in 1976 and a second time with the Sample Analysis on Mars (SAM) in-strument onboard the Curiosity rover in 2012. [1] [2] The presence of perchlorates found by the Phoenix mission in 2008 [3] lead to the discovery that organic molecules not only get oxidized during pyrolysis, but also chlorinated organic compounds can be pro-duced. [4] The parameters used for pyrolysis and the sample composition especially the distribution of organics and perchlorates within the sample and the concentrations of organics and perchlorate have a huge influence on the products created. It is possible to change the condi-tions of the pyrolysis by spatially separating the organ-ics from the perchlorates that the chloromethanes get the major product of the pyrolysis. This might help to understand the results of the (SAM) instrument yield-ing mono-, di- and trichloromethane and a chlorinated 4-hydrocarbon molecule. References: [1] Biemann K et al. (1977) JGR, 82, 4641-4658. [2] Grotzinger J. P et al. (2011) AGU Fall Meeting U13A-01 [3] Hecht M. H., et al. (2009) Science, 325 64-67. [4] Steininger H., Goesmann F., Goetz W. (2011) Planet. & Space Sci., 71, 9-17. Acknowledgments: This work was funded by DLR (FKZ 50QX1001)

Steininger, Harald; Goesmann, Fred; Goetz, Walter

2013-04-01

373

Integration of waste pyrolysis with coal/oil coprocessing  

Energy Technology Data Exchange (ETDEWEB)

HTI has developed a novel process, HTI CoPro Plus{trademark}, to produce alternative fuels and chemicals from the combined liquefaction of waste materials, coal, and heavy petroleum residues. Promising results have been obtained from a series of bench tests (PB-01 through PB-06) under the DOE Proof of Concept Program. Recently, HTI acquired a proven technology for the mild co-pyrolysis of used rubber tires and waste refinery or lube oils, developed by the University of Wyoming and Amoco. The feasibility of integration of pyrolysis with coal-oil coprocessing was studied in the eighth bench run (PB-08) of the program. The objective of Run PM-08 was to study the coprocessing of coal with oils derived from mild pyrolysis of scrap tires, waste plastics, and waste lube oils to obtain data required for economic comparisons with the DOE data base. A specific objective was also to study the performance of HTI's newly improved GelCat{trademark} catalyst in coal-waste coprocessing under low-high (Reactor 1-Reactor 2 temperatures) operating mode. This paper presents the results obtained from Run PB-08, a 17-day continuous operation conducted in August 1997. A total of 5 conditions, 343 C + pyrolysis oils derived from co-pyrolysis of rubber tires or a mixture of rubber tires and plastics with waste lube oil, were coprocessed with Black Thunder coal using HTI GelCat{trademark} catalyst. In the last condition, rubber tires were pyrolyzed with 524 C coal liquid to study the possible elimination of lube oil used as pyrolysis processing oil. Overall coal conversion above 90 W% was achieved. Distillate yield as high as 69.2 W% was obtained while hydrogen consumption was only 4.4 W%. The distinct advantage of this process is the increase in hydrogen efficiency as both hydrogen consumption and C{sub 1}{minus}C{sub 3} gas yield decrease. Economic evaluation shows that co-processing of plastics with oil, coal, or mixed oil and coal reduces the equivalent crude oil price to a competitive level. This demonstrates that a combined process of coal liquefaction and waste pyrolysis is economically viable.

Hu, J.; Zhou, P.; Lee, T.L.K.; Comolli, A.

1998-07-01

374

Modelling of pyrolysis of peat and biomass under combustion and gasification; Pyrolyysimalli turpeen ja biomassan poltolle ja kaasutukselle  

Energy Technology Data Exchange (ETDEWEB)

In the model developed during the research the chemical kinetics of pyrolysis is described with `the two competing reactions model`. Heat transfer in particle consists of convection and conduction. With the help of the model all the kinetic parameters of the two pyrolysis reactions are fitted with measured values. Also simple correlations for pyrolysis of peat under fluidized bed and pulverised flame conditions are given. The effect of the heating rate can be taken into account by using two competing Arrhenius-type reactions. In this model pyrolysis is modelled by using two reactions; one for the low temperature level and the other for the high temperature level. Both of these reactions consume the same unreacted fuel and this model is able to describe the pyrolysis at different temperature levels. Pyrolysis takes place in the heating stage of the particle before heterogeneous combustion and therefore temperature and density profiles inside the particle have to be solved simultaneously. The energy and mass balance equations of the particle form a set of partial differential equations (PDE), which is solved numerically by using so called method of lines, by converting PDE into a set of ordinary differential equations (ODE). The final solution of ODEs is received by using LSODE algorithm of Hindmash. An user friendly interface for the pyrolysis model is programmed by using Visual Basic enabling convenient variation of the conditions and observation of the results

Raiko, R.; Haukka, P.; Vehmaan-Kreula, M. [Tampere Univ. of Technology (Finland). Energy and Process Technology

1997-10-01

375

Catalytic Fast Pyrolysis: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Catalytic pyrolysis is a promising thermochemical conversion route for lignocellulosic biomass that produces chemicals and fuels compatible with current, petrochemical infrastructure. Catalytic modifications to pyrolysis bio-oils are geared towards the elimination and substitution of oxygen and oxygen-containing functionalities in addition to increasing the hydrogen to carbon ratio of the final products. Recent progress has focused on both hydrodeoxygenation and hydrogenation of bio-oil using a variety of metal catalysts and the production of aromatics from bio-oil using cracking zeolites. Research is currently focused on developing multi-functional catalysts used in situ that benefit from the advantages of both hydrodeoxygenation and zeolite cracking. Development of robust, highly selective catalysts will help achieve the goal of producing drop-in fuels and petrochemical commodities from wood and other lignocellulosic biomass streams. The current paper will examine these developments by means of a review of existing literature.

Theodore Dickerson; Juan Soria

2013-01-01

376

Key factors influencing the release and formation of HCN during iron containing coal pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Minerals inherently present in coal and iron-containing compounds externally added have an important influence on the formation and release of HCN-one of the NOx precursors during coal pyrolysis. The experiments on the pyrolysis of raw coal and demineralized coal with different carbon contents and iron-containing compounds were carried out in a fixed bed quartz reactor with the temperature programmed. The influencing factors of HCN formation and release during coal pyrolysis were examined. The results show that the effect of iron containing compounds in coal on HCN release depends on the coal types. And the iron added to coal by impregnation and precipitation method can significantly reduce the formation of HCN for lower coalification coals. Additionally, the effects of particle size and reaction time on HCN formation during pyrolysis of coal with iron were also studied. 13 refs., 4 figs., 4 tabs.

Xu, Ming-yan; Cui, Yin-ping; Qin, Ling-Li; Chang, Li-ping; Xie, Ke-chang [Taiyuan University of Technology, Taiyuan (China)

2007-02-15

377

Pyrolysis under H/sub 2/ and He of Utrillas coal  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis and hydropyrolysis at low temperature, 600 degrees C, of Utrillas coal were compared to determine differences in the product composition. Pyrolysis was carried out under helium at atmospheric pressure in a horizontal fixed-bed reactor with a heating rate of 7 degrees C min/sup -1/, and hydropyrolysis under hydrogen (3 MPa) in a fixed-bed gas-swept reactor with a heating rate of 10 degrees C min/sup -/ /sup 1/. Gas and water yields were similar, but the gases from hydropyrolysis had higher methane and lower CO/sub 2/ contents and therefore higher heating power. Tars from both techniques had similar elemental analyses but structural differences were observed by FT-i.r., /sup 1/H n.m.r. and gas chromatography. Hydropyrolysis yielded more tars than pyrolysis. The chars had analogous elemental and proximate analyses and calorific values. Hydropyrolysis was more effective for desulphurization than conventional pyrolysis. 16 refs., 6 figs., 3 tabs.

Ibarra, J.V.; Molinar, R.; Miranda, J.L.; Cypres, R.

1988-04-01

378

Development of ceramics via pyrolysis of metal organic polymers; Entwicklung metallorganisch basierter Keramiken  

Energy Technology Data Exchange (ETDEWEB)

In the polymer pyrolysis process a highly pure monomeric precursor is transferred via polyaddition or polycondensation reactions to a polymer of low volatility. In a protective atmosphere the issued polymer will be pyrolized yielding an amorphous ceramic, which can be crystallized at higher temperatures. The pyrolysis of polysilanes and polycarbosilanes reveals Si-C-ceramics, polysiloxanes decompose to Si-C-O-ceramics while polysilazanes and polysilylcarbodiimides will be transferred to Si-C-N and/or Si{sub 3}N{sub 4}-ceramics. The combination of different precursor systems used in the polymer pyrolysis process offers possibilities for the preparation of highly homogeneous multi component ceramics with tailored properties. Over the polymer pyrolysis route ceramic yields up to 90% can be achieved. The ceramic systems described in this article are used as monolithic moulding, as fibres or fibre-reinforced ceramic composites or as dip coated layers. (orig.) 48 refs.

Gadow, R.; Kienzle, A. [Stuttgart Univ. (Germany). Inst. fuer Fertigungstechnologie Keramischer Bauteile

1998-07-01

379

CO-PYROLYSIS OF POLYPROPYLENE WITH PETROLEUM OF BACIA DE CAMPOS  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, the process of co-pyrolysis of polypropylene (PP) residues with gas-oil was evaluated, varying thetemperature and the amount of polypropylene fed to the reactor. The polypropylene samples and gas-oil weresubmitted to the thermal co-pyrolysis in an inert atmosphere, varying the temperature and the amount of PP.The influence of the gas-oil was evaluated carrying the co-pyrolysis in the absence of PP. The pyrolysed liquidsproduced by this thermal treatment were characterized by modified gaseous chromatography in order toevaluate the yield in the range of distillation of diesel. As a result, the increase of PP amount lead to a reductionin the yield of the pyrolytic liquid and to an increase of the amount of solid generated. The effect of temperatureincrease showed an inverse result. The results show that plastic residue co-pyrolysys is a potential method forchemical recycling of plastic products.

DE ASSUMPÇÃO, Luiz Carlos Fonte Nova; MARQUES, Mônica Regina da Costa; CARBONELL, Montserrat Motas

2009-01-01