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1

Experimental study on low temperature pyrolysis of forestry residues  

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-07-01

2

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-01-01

3

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

Science.gov (United States)

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

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

2014-09-01

4

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-02-15

5

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 atmospheres. 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 TGA 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. Discrete mathematical models will be developed and validated using the experimental gasification data.

Zygourakis, K.

1988-01-01

6

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

7

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

8

Effect of pyrolysis temperature on the char micro-structure and reactivity of NO reduction  

Energy Technology Data Exchange (ETDEWEB)

A phenol-formaldehyde resin (PFR) and a bituminous coal (SH) were pyrolyzed at various temperatures. The structure and the char-NO reactivity were analyzed in order to examine the effect of pyrolysis temperature on the micro-structure of the resulting char and further on the reactivity towards NO. Micro-structure of the char samples was characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Raman spectroscopy. It was indicated that the micro-structure of PFR char and coal char experienced remarkable changes during pyrolysis, which resulted in the decrease of phenolic OH, aromatic hydrogen and more ordered structure. The pyrolysis temperature showed a weak impact on the reactivity of PFR char but comparatively remarkable impact on that of coal char at lower reaction temperature. Mineral matter in coal char presented a weak effect on the reactivity.

Yin, Y.S.; Zhang, J.; Sheng, C.D. [Southeast University, Nanjing (China). School of Energy & Environment

2009-05-15

9

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

Directory of Open Access Journals (Sweden)

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

Mohamad Azri Sukiran

2014-01-01

10

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

Directory of Open Access Journals (Sweden)

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

Monique Kort-Kamp Figueiredo

2011-07-01

11

Effect of pyrolysis temperature on the composition of the oils obtained from sewage sludge  

Energy Technology Data Exchange (ETDEWEB)

Sewage sludge was pyrolysed in a quartz reactor at 350, 450, 550 and 950 C. The pyrolysis oils from the sewage sludge were characterized in detail by means of gas chromatography-mass spectrometry (GC-MS). Changes in the composition of the oils related to the process conditions were assessed by normalizing the areas of the peaks. It was demonstrated that, as the temperature of pyrolysis increased from 350 to 950 C, the concentration of mono-aromatic hydrocarbons in the oils also increased. Conversely, phenol and its alkyl derivatives showed a strong decrease in their concentration as temperature rose. Polycyclic aromatic hydrocarbons (PAHs) with two to three rings passed through a maximum at a pyrolysis temperature of 450 C. PAHs with 4-5 rings also presented a major increase as temperature increased up to 450 C, the concentration at 950 C being slightly higher than that at 450 C. Quantification of the main compounds showed that sewage sludge pyrolysis oils contain significant quantities of potentially high-value hydrocarbons such as mono-aromatic hydrocarbons and phenolic compounds. The oils also contain substantial concentrations of PAHs, even at the lowest temperature of 350 C. The pathway to PAH formation is believed to be via the Diels-Alder reaction and also via secondary reactions of oxygenated compounds such as phenols. (author)

Sanchez, M.E.; Martinez, O.; Calvo, L.F. [Natural Resources Institute, University of Leon, Avda. de Portugal 41, 24071 Leon (Spain); Menendez, J.A.; Dominguez, A.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain); Bernad, P.L. [Department of Organic and Inorganic Chemistry, University of Oviedo, Oviedo (Spain)

2009-06-15

12

Effect of pyrolysis temperature on the composition of the oils obtained from sewage sludge  

International Nuclear Information System (INIS)

Sewage sludge was pyrolysed in a quartz reactor at 350, 450, 550 and 950 oC. The pyrolysis oils from the sewage sludge were characterized in detail by means of gas chromatography-mass spectrometry (GC-MS). Changes in the composition of the oils related to the process conditions were assessed by normalizing the areas of the peaks. It was demonstrated that, as the temperature of pyrolysis increased from 350 to 950 oC, the concentration of mono-aromatic hydrocarbons in the oils also increased. Conversely, phenol and its alkyl derivatives showed a strong decrease in their concentration as temperature rose. Polycyclic aromatic hydrocarbons (PAHs) with two to three rings passed through a maximum at a pyrolysis temperature of 450 oC. PAHs with 4-5 rings also presented a major increase as temperature increased up to 450 oC, the concentration at 950 oC being slightly higher than that at 450 oC. Quantification of the main compounds showed that sewage sludge pyrolysis oils contain significant quantities of potentially high-value hydrocarbons such as mono-aromatic hydrocarbons and phenolic compounds. The oils also contain substantial concentrations of PAHs, even at the lowest temperature of 350 oC. The pathway to PAH formation is believed to be via the Diels-Alder reaction and also via secondary reactions of oxygenated compounds such as phenols.

13

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

Science.gov (United States)

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

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

2014-04-01

14

Biophysical basis of hypoxic radioprotection by deoxygenated dextran-hemoglobin  

International Nuclear Information System (INIS)

Perfusion with deoxygenated dextran-hemoglobin provides an effective method for inducing hypoxic radioprotection of normal tissues during radiation treatment of tumors. In this study, the dependence of P50, the half-saturation pressure of oxygen binding to dextran-hemoglobin, was analyzed as a function of solution temperature and pH. The variation of attainable radioprotection with P50, and with the amount of collateral blood entering into the perfused region, was calculated. Upon perfusion of canine gracilis muscle with deoxygenated dextran-hemoglobin, a rapid onset of extensive venous hypoxia was observed

15

Diesel-like fuel obtained by pyrolysis of vegetable oils  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis reactions of soybean, palm tree, and castor oils were studied. The pyrolytic products were analyzed by CG-FID, CG-MS, and FTIR, showing the formation of olefins, paraffins, carboxylic acids, and aldehydes. The adequate choice of distillation temperature (DT) ranges made it possible to isolate fuels with physical-chemical properties comparable to those specified for petroleum based fuels. The catalytic upgrading of the soybean pyrolytic fuel over HZSM-5 zeolite at 400C was also studied and has shown a partial deoxygenation of the pyrolytic products.

Lima, Daniela G.; Soares, Valerio C.D.; Ribeiro, Eric B.; Cardoso, Erika C.V.; Rassi, Flavia C.; Mundim, Kleber C.; Rubim, Joel C.; Suarez, Paulo A.Z. [Instituto de Quimica, Universidade de Brasilia, CP 4478, 70919-970 Brasilia-DF (Brazil); Carvalho, Daniel A. [CEPAT-ANP, Brasilia-DF (Brazil)

2004-06-01

16

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

Directory of Open Access Journals (Sweden)

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

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

2014-02-01

17

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

Energy Technology Data Exchange (ETDEWEB)

To establish whether flash pyrolysis in the absence of air or oxygen is an efficient, low-cost way of converting lignoncellulosic waste (primarily sawdust) into a high-Btu fuel, CNRS determined experimentally experimentally the effect of temperature, moisture, and grain size on the volume, and calorific value of the gas produced. The results suggested that although the volume of gas increased with temperature, the calorific value peaked at 1300/sup 0/F and dropped off at higher temperatures. The presence of moisture in the wood, however, augmented both the gas production and the heating value for temperatures of up to 1600/sup 0/F. Furthermore, the speed of the gas release proved proportional to the surface area of the woody mass. Enthalpy determinations established that pyrolysis reactions producing a 500 Btu/CF gas were exothermic to about 1300/sup 0/F and then slightly endothermic beyond that point.

Deglise, S.; Richard, C.; Rolin, A.; Francois, H.

1980-11-01

18

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

Science.gov (United States)

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

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

2010-10-15

19

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

International Nuclear Information System (INIS)

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

20

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this paper has been to characterize the relation between the pyrolysis temperature of phenol-formaldehyde resin, the development of a porous structure, and the mechanical properties for the application of semipermeable membranes for gas separation. No previous study has dealt with this problem in its entirety. Phenol-formaldehyde resin showed an increasing trend toward micropore porosity in the temperature range from 500 till 1000C, together with closure of mesopores and macropor...

MONIKA UPOV; JAROSLAVA SVTILOV; ZDEN?K CHLUP; MARTIN ?ERN; ZUZANA WEISHAUPTOV; TOM SUCH; VLADIMR MACHOVI?; ZBYN?K SUCHARDA; MARGIT ALOUDKOV

2012-01-01

 
 
 
 
21

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

International Nuclear Information System (INIS)

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

22

Low-temperature pyrolysis of wood waste containing urea-formaldehyde resin  

Energy Technology Data Exchange (ETDEWEB)

A study of the first phase of a thermal two-step process of valorisation for waste containing urea-formaldehyde (UF resins) such as particle boards is presented. The first step of the process known as 'purification' is a low-temperature pyrolysis (250-300 C) achieved for the selective desorption of the additives and their recovery. The second step is a reduction/gasification of the carbonaceous residue by thermochemical attack in CO{sub 2} or in water vapour, to obtain CO/H{sub 2} gases. First experiments have been carried out on a thermobalance to check the feasibility of the selective desorption of UF resin from wood. It appears that the temperature ranges linked to the degradation of wood are different from those obtained for the degradation of urea-formaldehyde resin. Thus, these results enable a selective pyrolysis. Particle board pyrolysis is also studied on an analysis device allowing a semi-continuous analysis by Fourier transform infrared (FTIR) spectrometry of pyrolysis products such as CO, CO{sub 2}, CH{sub 4}, NH{sub 3} and HNCO. Elementary analysis and studies in calorimetric bomb enable the characterisation of residues after treatment. It appears that the nitrogen quantity eliminated is not influenced by the treatment temperature: the quality of the process does not depend on the temperature of the treatment. However, we also observe an acceleration of the carbon, oxygen and hydrogen elimination, which implies a loss of energy. These results are validated by the study of residues in calorimetric bomb, which leads to an energy loss of approximately 10% for a treatment temperature between 250 and 300 C. (author)

Girods, P.; Rogaume, Y.; Dufour, A.; Rogaume, C.; Zoulalian, A. [LERMAB, Nancy-Universite, UMR 1073, INRA, ENGREF, UHP, ENSTIB 27, rue du Merle Blanc, BP 1041, 88 051 Epinal (France)

2008-04-15

23

Saturation transfer electron paramagnetic resonance detection of sickle hemoglobin aggregation during deoxygenation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Spin-label saturation transfer EPR (ST-EPR) methods have been used to study the sickle hemoglobin (HbS) aggregation behaviors induced by slow deoxygenation at a constant temperature of 30 degrees C, and by a rapid temperature increase from 1 degree to 30 degrees C for fully deoxygenated HbS. For slow deoxygenation at 30 degrees C, we find that the effective HbS correlation time exhibits a continuous increase, without any abrupt transitions, suggesting that polymer formation in concentrated Hb...

Thiyagarajan, P.; Johnson, M. E.

1983-01-01

24

EPR spectra of deoxygenated high Tc superconductors  

Science.gov (United States)

EPR spectra of deoxygenated Bi-2201, Bi-2212, Bi-2223, Y-123, Tl-2223 and Hg-1223 have been investigated. Different types of Cu-clusters as octamers, tetramers, dimers and monomers have been identified. EPR spectra were recorded for more than 100 samples of these materials, from different batches of preparations and from different portions of the same batch with the aim of recording all varieties of the spectra in these materials. Different samples of the same compound gave different spectra, some of which were repetitive but some spectra of the samples of different compounds were also similar. In different samples of the same compounds, different combinations of the spectra of octamers, tetramers, dimers and monomers appeared. In all 20 different types of spectra could be observed. The role of Cu-tetramers in the mechanism of high temperature superconductivity has been hinted at.

Singh, R. J.; Sharma, P. K.; Singh, A.; Khan, S.

2001-08-01

25

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 80 d in an incubation experiment after soil amendment with the SL and each biochar at a dosage of 8 wt%. 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 10 yr). 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 CO2-C ha(-1)) showed a reduction of CO2 emissions between 301 and 932 kg CO2-C ha(-1)with respect to the direct application of raw sewage sludge after 10 yr. PMID:23891257

Mndez, A; Tarquis, A M; Saa-Requejo, A; Guerrero, F; Gasc, G

2013-10-01

26

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

27

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

28

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

Science.gov (United States)

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

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

2012-09-01

29

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

Science.gov (United States)

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

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

2014-11-01

30

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

Science.gov (United States)

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

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

2014-08-01

31

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

International Nuclear Information System (INIS)

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

32

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

DEFF Research Database (Denmark)

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

Bruun, Esben; Hauggaard-Nielsen, Henrik

2011-01-01

33

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

Directory of Open Access Journals (Sweden)

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

M.A.T. Jaya

2014-01-01

34

Catalytic pyrolysis of waste rice husk over mesoporous materials  

Science.gov (United States)

Catalytic fast pyrolysis of waste rice husk was carried out using pyrolysis-gas chromatography/mass spectrometry [Py-GC/MS]. Meso-MFI zeolite [Meso-MFI] was used as the catalyst. In addition, a 0.5-wt.% platinum [Pt] was ion-exchanged into Meso-MFI to examine the effect of Pt addition. Using a catalytic upgrading method, the activities of the catalysts were evaluated in terms of product composition and deoxygenation. The structure and acid site characteristics of the catalysts were analyzed by Brunauer-Emmett-Teller surface area measurement and NH3 temperature-programmed desorption analysis. Catalytic upgrading reduced the amount of oxygenates in the product vapor due to the cracking reaction of the catalysts. Levoglucosan, a polymeric oxygenate species, was completely decomposed without being detected. While the amount of heavy phenols was reduced by catalytic upgrading, the amount of light phenols was increased because of the catalytic cracking of heavy phenols into light phenols and aromatics. The amount of aromatics increased remarkably as a result of catalytic upgrading, which is attributed to the strong Brnsted acid sites and the shape selectivity of the Meso-MFI catalyst. The addition of Pt made the Meso-MFI catalyst even more active in deoxygenation and in the production of aromatics.

Jeon, Mi-Jin; Kim, Seung-Soo; Jeon, Jong-Ki; Park, Sung Hoon; Kim, Ji Man; Sohn, Jung Min; Lee, See-Hoon; Park, Young-Kwon

2012-01-01

35

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

International Nuclear Information System (INIS)

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

36

PCDD/PCDF behavior in low-temperature pyrolysis of PCP-contaminated sandy soil.  

Science.gov (United States)

This study investigates the behavior of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) formation, dechlorination and destruction in PCP-contaminated sandy soil by low-temperature thermal treatment. Experimental tests were carried out in a nitrogen atmosphere in the temperature range of 200-400 C with a treatment time of 30 min. 70% of PCP removal from the soil was achieved, resulting in 1436230 ng/kg, the highest PCDD/F formation at 250 C; however, the highest toxic concentration was measured around 4.200.62 ng TEQ/kg at 300 C with 80% PCP removal from the soil. Further analysis has revealed that OCDD is the most dominant congener that is supposed to be formed from the pyrolysis of PCP, while OCDF is the second prevailing congener, possibly due to pyrolysis of 2,3,4,5-TeCP being a main byproduct of PCP pyrolysis. Detection of less chlorinated dioxins and furans over 300 C indicates the dechlorination of highly chlorinated dioxins and furans, especially octachlorinated dibenzo-p-dioxin (OCDD) at 350 C and 400 C. Desorption from soil was supposed as a main mechanism for the distribution of PCDD/Fs in the gaseous phase, and not much difference in dioxins and furan levels was observed at 350 C and 400 C in the gaseous phase. Therefore, 350 C is the most appropriate temperature to remove most PCP and PCDD/Fs from soil, as well as to meet PCDD/F emission standards (0.1 ng I-TEQ/Nm(3)). PMID:23220751

Thuan, Ngo Thi; Dien, Nguyen Thanh; Chang, Moo Been

2013-01-15

37

Low substrate temperature synthesis of carbon nanowalls by ultrasonic spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

In this paper, we report the synthesis of two-dimensional wall like carbon nanostructures (i.e. carbon nanowalls) by ultrasonic spray pyrolysis of ethanol and fullerene mixture. At higher temperature carbon nanofibers were formed on the substrate placed at the center of the reactor tube, whereas carbon nanowalls were observed on the substrate placed downstream of the tube below 100 {sup o}C. Spaces between the nanowalls changed with distance of the substrates from the furnace. Qualitative analysis of materials was performed using scanning electron microscopy, transmission electron microscopy and Raman spectroscopy.

Zhang Jianhui [Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Khatri, Ishwor, E-mail: ishwor_nep2000@yahoo.co [Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Kishi, Naoki [Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Mominuzzaman, Sharif M. [Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000 (Bangladesh); Soga, Tetsuo; Jimbo, Takashi [Department of Frontier Materials, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

2011-04-29

38

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

2013-12-01

39

Substitution of fossil fuels by using low temperature pyrolysis of agricultural residues  

International Nuclear Information System (INIS)

Externally heated rotary kiln pyrolysis reactor is used as a new process technology for the conversion of biomass into useful primary energy products. A 3 MW pyrolysis pilot plant is being operated for a period of two years using agricultural residues. Several analytical methods are applied to provide an insight into the complex process of pyrolysis. Fundamentals for an advanced pyrolysis model approach will be obtained by the results of the pilot plant. (author)

40

Preparation of levoglucosenone through sulfuric acid promoted pyrolysis of bagasse at low temperature.  

Science.gov (United States)

Fast pyrolysis of bagasse pretreated by sulfuric acid was conducted in a fixed bed reactor to prepare levoglucosenone (LGO), a very important anhydrosugar for organic synthesis. The liquid yield and LGO yield were studied at temperatures from 240 to 350 C and sulfuric acid loadings from 0.92 to 7.10 wt.%. An optimal LGO yield of 7.58 wt.% was obtained at 270 C with a sulfuric acid pretreatment concentration of 0.05 M (corresponding to 4.28 wt.% sulfuric acid loading). For comparison, microcrystalline cellulose pretreated by 0.05 M sulfuric acid solution was pyrolyzed at temperature from 270 C to 320 C, and bagasse loaded with 3-5 wt.% phosphoric acid was pyrolyzed at temperature from 270 C to 350 C. The highest yield of LGO from bagasse was 30% higher than that from microcrystalline cellulose, and treatment with sulfuric acid allowed a 21% higher yield than treatment with phosphoric acid. PMID:22047659

Sui, Xian-wei; Wang, Zhi; Liao, Bing; Zhang, Ying; Guo, Qing-xiang

2012-01-01

 
 
 
 
41

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

International Nuclear Information System (INIS)

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.

42

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

Energy Technology Data Exchange (ETDEWEB)

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{sup -4} {Omega}-cm for a doping percentage of 50 mol% of fluorine in 0.5 M solution, deposited at 400 {sup o}C. Hall coefficient analyses and secondary ion mass spectrometry (SIMS) measured the electron carrier concentration that varies from 3.52 x 10{sup 20} cm{sup -3} to 6.21 x 10{sup 20} cm{sup -3} with increasing fluorine content from 4.6 x 10{sup 20} cm{sup -3} to 7.2 x 10{sup 20} cm{sup -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.

Lin, Chin-Ching, E-mail: chinchinglin@itri.org.t [Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan (China); Chiang, Mei-Ching [Material and Chemical Research Laboratories, Industrial Technology Research Institute, Hsinchu 310, Taiwan (China); Chen, Yu-Wei [Department of Materials Science and Engineering, National Chiao Tung University, Hsinchu 300, Taiwan (China)

2009-12-15

43

Influence of inherent minerals and pyrolysis temperature on the yield of pyrolysates of some Pakistani coals  

International Nuclear Information System (INIS)

An analytical method has been developed to quantitize tar, liquids and gaseous products resulting from the flash pyrolysis of sub-bituminous Makarwal coal. The method involves the thermal decomposition of 200 mg of 85-mesh size coal at 690 deg. C under the flow of nitrogen using Shimadzu PYR-2A open tubular pyrolyzer. The resulting tar and liquid fractions were separated using two traps at the exit of the pyrolyzer while the gaseous products leaving the traps were on line injected to gas chromatograph equipped with porapak Q column and flame ionization detector for the analysis. Effect of demineralization on the yields of products was investigated by treating raw samples with 2 M HCl. Removal of inherent minerals from coal by acid wash decreased the yield of total volatiles indicating catalytic properties of mineral under the condition used in present study. The influence of pyrolysis temperature on the yield of pyrolysates and hydrocarbon gases, resulting from raw coal samples, was studied over the temperature range of 500-770 deg. C.

44

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

Science.gov (United States)

Pyrolysis of sewage sludge was studied in a free-fall reactor at 1000-1400 C. The results showed that the volatile matter in the sludge could be completely released to gaseous product at 1300 C. The high temperature was in favor of H2 and CO in the produced gas. However, the low heating value (LHV) of the gas decreased from 15.68 MJ/Nm(3) to 9.10 MJ/Nm(3) with temperature increasing from 1000 C to 1400 C. The obtained residual solid was characterized by high ash content. The energy balance indicated that the most heating value in the sludge was in the gaseous product. PMID:24220150

Zhang, Leguan; Xiao, Bo; Hu, Zhiquan; Liu, Shiming; Cheng, Gong; He, Piwen; Sun, Lei

2014-01-01

45

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

Directory of Open Access Journals (Sweden)

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

MONIKA UPOV

2012-03-01

46

The effects of temperature and catalysts on the pyrolysis of industrial wastes (herb residue).  

Science.gov (United States)

Pyrolysis of herb residue was investigated in a fixed-bed to determine the effects of pyrolysis temperature and catalysts (ZSM-5, Al-SBA-15 and alumina) on the products yields and the qualities of bio-oils. The results indicated that the maximum bio-oil yield of 34.26% was obtained at 450 degrees Celsius with 10 wt.% alumina catalyst loaded. The pyrolytic oils were examined by ultimate analysis and calorific values determination, and the results indicated that the presence of all catalysts decreased the oxygen content of bio-oils and increased the calorific values. The order of the catalytic effect for upgrading the pyrolytic oil was Al(2)O(3)>Al-SBA-15>ZSM-5. The bio-oil with the lowest oxygen content (26.71%) and the highest calorific value (25.94 MJ kg(-1)) was obtained with 20 wt.% alumina catalyst loaded. Furthermore, the gas chromatography/mass spectrometry (GC/MS) was used in order to investigate the components of obtained pyrolytic oils. It was found that the alumina catalyst could clearly enhance the formation of aliphatics and aromatics. PMID:20071166

Wang, Pan; Zhan, Sihui; Yu, Hongbing; Xue, Xufang; Hong, Nan

2010-05-01

47

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

Science.gov (United States)

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

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

2011-03-23

48

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)

49

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

50

Flame Temperature Effect on the Structure of SiC Nanoparticles Grown by Laser Pyrolysis  

International Nuclear Information System (INIS)

Small SiC nanoparticles (10 nm diameter) have been grown in a flow reactor by CO2 laser pyrolysis from a C2H2 and SiH4 mixture. The laser radiation is strongly absorbed by SiH4 vibration. The energy is transferred to the reactive medium and leads to the dissociation of molecules and the subsequent growth of the nanoparticles. The reaction happens with a flame. The purpose of the experiments reported in this paper is to limit the size of the growing particles to the nanometric scale for which specific properties are expected to appear. Therefore the effects of experimental parameters on the structure and chemical composition of nanoparticles have been investigated. For a given reactive mixture and gas velocity, the flame temperature is governed by the laser power. In this study, the temperature was varied from 875 deg. C to 1100 deg. C. The chemical analysis of the products indicate that their composition is a function of the temperature. For the same C/Si atomic ratio in the gaseous phase, the C/Si ratio in the powder increases from 0.7 at 875 deg. C up to 1.02 at 1100 deg. C, indicating a growth mechanism limited by C2H2 dissociation. As expected, X-ray diffraction has shown an improved crystallisation with increasing temperature. Transmission electron microscopy observations have revealed the formation of 10 nm grains for all values of laser power (or flame temperature). These grains appearor flame temperature). These grains appear amorphous at low temperature, whereas they contain an increasing number of nanocrystals (2 nm diameter) when the temperature increases. These results pave the way to a better control of the structure and chemical composition of laser synthesised SiC nanoparticles in the 10 nm range

51

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

52

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

Energy Technology Data Exchange (ETDEWEB)

Bulk petroleum generation by programmed-temperature pyrolysis of immature (R[sub r] = 0.48%) Posidonia (Toarcian) Shale samples at heating rates of 0.1, 0.7, and 5.0 K/min has been studied comparatively under open- and closed-system conditions, using the microscale sealed vessel (MSSV) technique in the latter case. The comparison of formation rates required a differentiation (vs. temperature) of closed-system cumulative product evolution profiles. The kinetic analysis assuming twenty-five first order parallel reactions with activation energies regularly spaced between 46 and 70 kcal/mol and a single pre-exponential factor A yielded the same value of A = 1.08[center dot]10[sup 16] min[sup [minus]1] and very similar petroleum potential vs. activation energy distributions centered around 54 kcal/mol in both cases. In particular, both approaches turned out to be in excellent agreement with respect to predicting temperature ranges of oil and gas formation under geological heating conditions. This is in contrast to the case of petroleum yield assessment which appears to be more system-dependent. 67 refs., 6 figs.

Schenk, H.J.; Horsfield, B. (Juelich Research Centre (Germany))

1993-02-01

53

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

54

Kinetics of the low-temperature pyrolysis of polyethene, polypropene and polystyrene modeling, experimental determination and comparison with literature models and data  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The pyrolysis kinetics of low-density polyethylene, high-density polyethylene, polypropylene, and polystyrene has been studied at temperatures below 450 C. In addition, a literature review on the low-temperature pyrolysis of these polymers has been conducted and has revealed that the scatter in the reported kinetic data is significant, which is most probably due to the use of simple first-order kinetic models to interpret the experimental data. This model type is only applicable in a small co...

Westerhout, R. W. J.; Waanders, J.; Kuipers, J. A. M.; Swaaij, W. P. M.

1997-01-01

55

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

Directory of Open Access Journals (Sweden)

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

Victoria Nelissen

2014-01-01

56

Deoxygenation of the Baltic Sea during the last century.  

Science.gov (United States)

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

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

2014-04-15

57

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

Science.gov (United States)

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

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

2012-05-23

58

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

Science.gov (United States)

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

59

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

Energy Technology Data Exchange (ETDEWEB)

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

Rao, T. Prasada, E-mail: prasadview@gmail.co [Department of physics, National Institute of Technology, Tiruchirappalli 620015 (India); Kumar, M.C. Santhosh, E-mail: santhoshmc@yahoo.co [Department of physics, National Institute of Technology, Tiruchirappalli 620015 (India); Angayarkanni, S. Anbumozhi; Ashok, M. [Department of physics, National Institute of Technology, Tiruchirappalli 620015 (India)

2009-10-19

60

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.

 
 
 
 
61

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

Science.gov (United States)

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 55SBA-15-necklacelike at 270C and 60barH2 pressure within 6h 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. PMID:24011181

2013-01-01

62

Catalytic methods of deoxygenating water: Final report  

International Nuclear Information System (INIS)

As part of a programme on the optimization of pressurized water reactor (PWR) secondary side water treatment, methods of reducing the oxygen concentration from the feedwater without the use of toxic chemicals or chemicals that may produce undesirable by-products was sought for. Hydrogen was identified as such a chemical. Gamma radiation and catalysis were studied as means of promoting the reaction between oxygen and hydrogen, to form water with no byproducts. Two types of wet-proofed catalysts---the random bed and the ordered bed catalysts---were developed and tested under two modes of operation---liquid phase and gasliquid phase. Oxygen reduction down to concentrations of 1 ppB or less was achieved. Analytical models were developed for the processes from kinetic studies. Equations for use in designing deoxygenators for steam generator systems were derived. Computer simulations and experimental studies showed that gamma irradiation in the presence of hydrogen reduced oxygen to the low ppB levels at rates corresponding to G(/minus/O2) values in the range 1.5 to 2 molecules100 eV gamma energy absorbed. The gamma source strength required for reducing oxygen concentrations to acceptable levels was estimated. The location of the deoxygenator in a steam generator system is discussed. 41 refs., 21 figs., 11 tabs

63

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

Science.gov (United States)

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

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

2014-06-01

64

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

International Nuclear Information System (INIS)

A pyrolysis - neutron activation analysis procedure was developed and applied to the speciation of arsenic in solid biological samples. The method, developed with the aid of radiochemically labelled arsenic compounds, was applied to the determination of the ratio of inorganic to organic arsenic species in commercial shrimps and in NBS standard reference materials such as oysters and orchard leaves. The results show different relative amounts of inorganic arsenic content in the samples analyzed. (author) 13 refs.; 5 tables

65

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

International Nuclear Information System (INIS)

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

66

Modeling of biomass pyrolysis  

International Nuclear Information System (INIS)

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

67

Pyrolysis of Coal  

Directory of Open Access Journals (Sweden)

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

Ra?enovi?, A.

2006-07-01

68

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-12-21

69

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

Energy Technology Data Exchange (ETDEWEB)

Spent TBP, a combustible waste solvent, is not readily incinerated due to problems associated with condensation of phosphoric acid. A two-stage pyrolysis system that consists of a low-temperature pyrolysis at ? 450 .deg. C and a higher-temperature steam-assisted pyrolysis at ? 800 .deg .C has been proposed as an alternative oxidation technology for the destruction of spent TBP. Off-gas from this two-stage pyrolysis system includes various unburned hydrocarbons (UHCs) as well as complete-steam reforming products, CO and H{sub 2}, which should be substantially oxidized prior to emission into the atmosphere. Catalytic oxidation is considered as an advantageous and safe treatment method for UHCs. A Pt-based honeycomb monolith is considered to be an effective combustion catalyst for UHCs. Numerous studies on platinum monolith honeycomb reactors have focused on catalytic combustion of a single fuel. The present study investigated the catalytic oxidation of a mixture of various UHCs from the proposed two-stage pyrolysis of waste TBP, in a platinum monolith honeycomb reactor. A wide ranging parametric model study was performed to establish proper conditions of a platinum monolith honeycomb reactor for the bench-scale system design.

Yang, Heechul; Lee, Minwoo; Chung, Dongyong; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

70

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

Science.gov (United States)

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

Ortel, Marlis; Wagner, Veit

2013-01-01

71

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

International Nuclear Information System (INIS)

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

72

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 oitrogen 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.

73

Synthesis gas production by biomass pyrolysis: Effect of reactor temperature on product distribution  

Energy Technology Data Exchange (ETDEWEB)

This paper describes mass, C, H, and O balances for wood chips pyrolysis experiments performed in a tubular reactor under conditions of rich H{sub 2} gas production (700-1000 C) and for determined solid heating rates (20-40 C s{sup -1}). Permanent gases (H{sub 2}, CO, CH{sub 4}, CO{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}), water, aromatic tar (10 compounds from benzene to phenanthrene and phenols), and char were considered in the balance calculations. Hydrogen (H) from dry wood is mainly converted into CH{sub 4} (more than 30% mol. of H at 900 C), H{sub 2} (from 9% to 36% mol. from 700 to 1000 C), H{sub 2}O, and C{sub 2}H{sub 4}. The molar balances showed that the important yield increase of H{sub 2} from 800 to 1000 C (0.10 Nm{sup 3} kg{sup -1} to 0.24 Nm{sup 3} kg{sup -1} d.a.f. wood) cannot be solely explained by the analyzed hydrocarbon compounds conversion (CH{sub 4}, C{sub 2}, aromatic tar). Possible mechanisms of H{sub 2} production from wood pyrolysis are discussed. (author)

Dufour, A. [Gaz de France, Research and Development Division, 361 avenue du President Wilson, B.P. 33, 93 211 Saint Denis la Plaine cedex (France); Girods, P.; Rogaume, Y.; Zoulalian, A. [Nancy-Universite, LERMAB, ENSTIB, 27 rue du Merle Blanc, B.P. 1041, 88051 Epinal (France); Masson, E. [CRITTBois, 27 rue du Merle Blanc, B.P. 1041, 88051 Epinal (France)

2009-02-15

74

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)

75

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

International Nuclear Information System (INIS)

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

76

The temperature's influence on the selectivity between HNCO and HCN from pyrolysis of 2,5-diketopiperazine and 2-pyridone  

Energy Technology Data Exchange (ETDEWEB)

Two cyclic amides, 2-pyridone and 2,5-diketopiperazine (DKP), were pyrolysed at temperatures ranging from 700 to 1100{sup o}C. Pyridone is the only one of the four main nitrogen functionalities found in coal that is likely to form HNCO under pyrolysis. DKP is a primary pyrolysis product from proteins, which are the main nitrogen source in biomass. The formation of HNCO from biomass has been suggested to originate from DKP and other cyclic amides. The aromatic 2-pyridone was thermally more stable than the non-aromatic DKP. Both amides formed HCN, HNCO and NH{sub 3}. The NH{sub 3} yields, about 3 4% for 2-pyridone and 10% for DKP, were almost independent of temperature. The HCN yield on the other hand showed strong temperature dependence and increased with temperature for both of the cyclic amides. The HNCO yield decreased with increasing temperature for DKP over the whole temperature interval. For 2-pyridone, the pyrolysis was incomplete at the lowest temperature in the investigation. Between 900 and 1100{sup o}C, the pyrolysis of 2-pyridone was complete and the HNCO yield decreased with increasing temperature. The HNCO/HCN ratio for both of the cyclic amides decreased with increasing temperature over the whole investigated temperature range. The finding in literature that the HNCO formation from cracking of coal tars produced a maximum HNCO yield at an intermediate temperature, is explained by the thermal stability of pyridone at low temperatures and the selectivity towards HCN at high temperatures. 30 refs., 12 figs.

Karl-Martin Hansson; Jessica Samuelsson; Lars-Erik Aamand; Claes Tullin [Chalmers University of Technology, Gothenburg (Sweden)

2003-11-01

77

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

Science.gov (United States)

Pyrolysis of plant and animal wastes produces a complex mixture of phosphorus species in amorphous, semicrystalline, and crystalline inorganic phases, organic (char) components, and within organo-mineral complexes. To understand the solubility of different phosphorus species, plant (cottonseed hull) and manure (broiler litter) wastes were pyrolyzed at 350, 500, 650, and 800 C and exposed to increasingly more rigorous extraction procedures: water (16 h), Mehlich 3 (1 mM EDTA at pH 2.5 for 5 min), oxalate (200 mM oxalate at pH 3.5 for 4 h), NaOH-EDTA (250 mM NaOH + 5 mM EDTA for 16 h), and total by microwave digestion (concentrated HNO3/HCl + 30% H2O2). Relative to the total (microwave digestible) P, the percentage of extractable P increased in the following order: M3 biochars and water biochars. Solution phase (31)P NMR analysis of NaOH-EDTA extracts showed the conversion of phytate to inorganic P by pyrolysis of manure and plant wastes at 350 C. Inorganic orthophosphate (PO4(3-)) became the sole species of ? 500 C manure biochars, whereas pyrophosphate (P2O7(4-)) persisted in plant biochars up to 650 C. These observations suggested the predominance of (i) amorphous (rather than crystalline) calcium phosphate in manure biochars, especially at ? 650 C, and (ii) strongly complexed pyrophosphate in plant biochars (especially at 350-500 C). Correlation (Pearson's) was observed (i) between electric conductivity and ash content of biochars with the amount of inorganic P species and (ii) between total organic carbon and volatile matter contents with the organic P species. PMID:24495088

Uchimiya, Minori; Hiradate, Syuntaro

2014-02-26

78

Large-scale reactive molecular dynamics simulation and kinetic modeling of high-temperature pyrolysis of the Gloeocapsomorphaprisca microfossils.  

Science.gov (United States)

The ability to predict accurately the thermal conversion of complex carbonaceous materials is of value in both petroleum exploration and refining operations. Modeling the thermal cracking of kerogen under basinal heating conditions improves the predrill prediction of oil and gas yields and quality, thereby ultimately lowering the exploration risk. Modeling the chemical structure and reactivity of asphaltene from petroleum vacuum residues enables prediction of coke formation and properties in refinery processes, thereby lowering operating cost. The chemical structure-chemical yield modeling (CS-CYM) developed by Freund et al. is more rigorous, time-consuming, and requires a great deal of chemical insight into reaction network and reaction kinetics. The present work explores the applicability of a more fundamental atomistic simulation using the quantum mechanically based reactive force field to predict the product yield and overall kinetics of decomposition of two biopolymers, namely, the Kukersite and Gutternberg. Reactive molecular dynamics (RMD) simulations were performed on systems consisting of 10(4) to 10(5) atoms at different densities and temperatures to derive the overall kinetic parameters and a lumped kinetic model for pyrolysis. The kinetic parameters derived from the simulated pyrolysis of an individual component and the mixture of all four components in Guttenberg reveal the role of cross-talk between the fragments and enhanced reactivity of component A by radicals from other components. The Arrhenius extrapolation of the model yields reasonable prediction for the overall barrier for cracking. Because simulations were run at very high temperature (T > 1500 K) to study cracking within the simulation time of up to 1 ns, it, however, led to the entropically favored ethylene formation as a dominant decomposition route. Future work will focus on evaluating the applicability of accelerated reactive MD approaches to study cracking. PMID:24821589

Zou, Chenyu; Raman, Sumathy; van Duin, Adri C T

2014-06-12

79

Deoxygenation of Plant Fatty Acid using NiSnK/ SiO2 as Catalyst  

International Nuclear Information System (INIS)

Environmental friendly bio-oil which offers supply reliability as a potential alternative fuel, has spurred to rapid development of bio fuels technology. Palm oil is a potential renewable energy source for bio fuels production in the future and Malaysia is one of the world largest palm oil producers. However, undesired oxygen content in the plant fatty acid that contributes to low energy density, high viscosity, and low stability, makes the palm oil not effective to be used as bio fuels directly. In the present study, the performance of silica supported trimetal catalyst, NiSnK/ SiO2, on deoxygenation of used palm oil was evaluated. In addition, the effects of operating parameters, such as reaction temperature and weight hourly space velocity were investigated. Conversion of palmitic acid as high as 90 % was achieved in deoxygenation of used palm oil at reaction temperature 350 degree Celsius. In order to have a better understanding on the deoxygenation reaction, model compound system using the major saturated fatty acid in the used palm oil, palmitic acid was also carried out. Palmitic acid was found mainly decarboxylated into n-pentadecane with some decarboxylation and isomerization products. (author)

80

Ocean (Deoxygenation Across the Last Deglaciation: Insights for the Future  

Directory of Open Access Journals (Sweden)

Full Text Available Anthropogenic warming is expected to drive oxygen out of the ocean as the water temperature rises and the rate of exchange between subsurface waters and the atmosphere slows due to enhanced upper ocean density stratification. Observations from recent decades are tantalizingly consistent with this prediction, though these changes remain subtle in the face of natural variability. Earth system model projections unanimously predict a long-term decrease in the global ocean oxygen inventory, but show regional discrepancies, particularly in the most oxygen-depleted waters, owing to the complex interplay between oxygen supply pathways and oxygen consumption. The geological record provides an orthogonal perspective, showing how the oceanic oxygen content varied in response to prior episodes of climate change. These past changes were much slower than the current, anthropogenic change, but can help to appraise sensitivities, and point toward potentially dominant mechanisms of change. Consistent with the model projections, marine sediments recorded an overall expansion of low-oxygen waters in the upper ocean as it warmed at the end of the last ice age. This expansion was not linearly related with temperature, though, but reached a deoxygenation extreme midway through the warming. Meanwhile, the deep ocean became better oxygenated, opposite the general expectation. These observations require that significant changes in apparent oxygen utilization occurred, suggesting that they will also be important in the future.

Samuel L. Jaccard

2014-03-01

 
 
 
 
81

Preconversion catalytic deoxygenation of phenolic functional groups. Quarterly technical progress report, April 1, 1992--June 30, 1992  

Energy Technology Data Exchange (ETDEWEB)

Aryl carbon-oxygen bond cleavage is a chemical transformation of importance in coal liquefaction and the upgrading of coal liquids as well as in the synthesis of natural products. There have been numerous attempts to discover general methods for the cleavage of aryl carbon-oxygen bonds. All the stoichiometric organic methods for phenol deoxygenation have limited applications and involve expensive reagents. Catalytic method, for the hydrodeoxygenation (HDO) of phenols involve supported transition metal oxides, such as 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}, and Fe{sub 2}O{sub 3}/SiO{sub 2}. Typical phenol hydrodeoxygenation conditions involve hydrogen pressures in excess of 100 atm and temperatures in excess of 200{degrees}C. Under these conditions arene ring hydrogenation is generally found to compete with phenol deoxygenation; and the coproduct water is found to impair the activity of the catalysts. This proposed research offers the possibility of effecting the selective catalytic deoxygenation of phenolic functional groups using CO. The deoxygenation of phenols by carbon monoxide mediated by Ir(triphos)OAr has provided us with a catalytic Phenol deoxygenation pathway, through the elimination of CO{sub 2} and formation of a benzyne intermediate. Although the [Pt(triphos)(O-Ph-Me)]PF{sub 6} system is not expected to be as efficient a catalyst as some of the other transition metals systems we are currently exploring, it will provide more information about the deoxygenation mechanism in these triphos complexes. This is due to the presence of the structurally sensitive {sup 3l}P--{sup 195}Pt coupling constant and comparisons to the extensively studied Pt(dppe)(O-Ph){sub 2} systems.

Kubiak, C.P.

1992-11-01

82

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

2012-06-01

83

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

International Nuclear Information System (INIS)

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

84

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

International Nuclear Information System (INIS)

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

85

Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 5, September 15, 1988--December 15, 1988  

Energy Technology Data Exchange (ETDEWEB)

Coals of different ranks will be pyrolyzed in a microscope hot-stage reactor using inert and reacting atmospheres. 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 TGA 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. Discrete mathematical models will be developed and validated using the experimental gasification data.

Zygourakis, K.

1988-12-31

86

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

87

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

Science.gov (United States)

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

Nicholas, Christpher P; Boldingh, Edwin P

2013-12-17

88

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

International Nuclear Information System (INIS)

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

89

Catalytic pyrolysis of Laminaria japonica over nanoporous catalysts using Py-GC/MS  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract The catalytic pyrolysis of Laminaria japonica was carried out over a hierarchical meso-MFI zeolite (Meso-MFI and nanoporous Al-MCM-48 using pyrolysis gas chromatography/mass spectrometry (Py-GC/MS. The effect of the catalyst type on the product distribution and chemical composition of the bio-oil was examined using Py-GC/MS. The Meso-MFI exhibited a higher activity in deoxygenation and aromatization during the catalytic pyrolysis of L. japonica. Meanwhile, the catalytic activity of Al-MCM-48 was lower than that of Meso-MFI due to its weak acidity.

Jeon Jong-Ki

2011-01-01

90

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

2010-09-01

91

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

Science.gov (United States)

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

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

2014-09-01

92

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

93

Pyrolysis of Table Sugar  

Science.gov (United States)

Table sugars were pyrolyzed at different temperatures (300, 400, and 500C) in a fixed-bed reactor. The effect of pyrolysis temperature on yields of liquid, solid, and gaseous products was investigated. As expected the yield of liquid products gradually increased and the yield of solid products gradually decreased when the pyrolysis temperature was raised. The yield of liquid products was greatest (52?wt%) at 500C. The composition of bio-oils extracted with diethyl ether was identified by means of gas chromatography mass spectrometry (GC-MS), nuclear magnetic resonance (1H-NMR), and Fourier transform infrared spectroscopy (FTIR). The following compounds were observed in bio-oils produced from the pyrolysis of table sugar at 500C: 1,4:3,6-dianhydro-?-d-glucopyranose, 5-(hydroxymethyl) furfural, 5-acetoxymethyl-2-furaldehyde, and cyclotetradecane liquid product. The relative concentration of 5-(hydroxymethyl) furfural was the highest in bio-oils obtained from pyrolysis of table sugars at 500C. PMID:24223500

Karagoz, Selhan

2013-01-01

94

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

2013-05-14

95

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

Science.gov (United States)

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

Nicholas, Christopher P; Boldingh, Edwin P

2013-12-17

96

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

Scientific Electronic Library Online (English)

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

Michal, Novk.

97

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

98

An experimental study of fragmentation of coals during fast pyrolysis at high temperature and pressure  

Energy Technology Data Exchange (ETDEWEB)

An experimental apparatus has been developed in order to perform tests of primary fragmentation of solid fuels under severe heating conditions (up to 2200 K and 12 bar). Particles are laid on the strip and pyrolyzed under inert conditions, fragments are recovered and analyzed by a laser granulometer to assess the fragmentation propensity of the fuel. Experiments have been carried out at temperatures between 1400 K and 1900 K, heating rate of 5000 K/s, pressure in the range 1-12 bar. Four different coals have been studied: Gracem, Venezuelan, Omsky, and Kleincopje, classified respectively as anthracite, high and medium volatile bituminous coals. Results show that primary fragmentation at high heating rate and high temperature may result in the formation of relatively coarse fragments and sometimes in a multitude of fines. The probability of fragmentation and the propensity to form coarse versus small fragments varies from coal to coal. For a given coal fragmentation increases monotonously with temperature, whereas the effect of pressure is nonmonotonous. The role of different chemico-physical properties of coals on the pattern and the extent of primary fragmentation is discussed, in particular volatile matter content, ash melting point, rigidity and porosity of the carbon structure and swelling index. 30 refs., 8 figs., 3 tabs.

O. Senneca; M. Urciuolo; R. Chirone; D. Cumbo [Istituto di Ricerche sulla Combustione, Naples (Italy)

2011-09-15

99

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

International Nuclear Information System (INIS)

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

100

Pyrolysis of rapeseed cake  

Energy Technology Data Exchange (ETDEWEB)

In this study, biomass in the form of rapeseed cake was pyrolyzed in a fixed bed stainless steel reactor under static atmosphere at varying temperatures of 450, 550, 650, 750, and 850{sup o}C and at heating rates of either 15{sup o}C min{sup -1} or 25{sup o}C min{sup -1}. The studies reported here were aimed towards understanding the influence of heating rate and pyrolysis temperature on product yield. The maximum oil yield was observed to be evolving at 650{sup o}C pyrolysis temperature and at a heating rate of 15{sup o}C min{sup -1}. The results showed the potential of rapeseed cake as an important source of alternative liquid fuel. (author)

Karaosmanoglu, F.; Culcuoglu, E.

2001-05-15

 
 
 
 
101

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

Science.gov (United States)

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

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

2012-11-01

102

Catalytic pyrolysis of biomass in a fluidized bed reactor  

Energy Technology Data Exchange (ETDEWEB)

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

Aho, A.

2009-07-01

103

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

International Nuclear Information System (INIS)

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

104

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

International Nuclear Information System (INIS)

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

105

Coherence length in deoxygenated (1 0 3)/(0 1 3) oriented YBCO superconductor films  

International Nuclear Information System (INIS)

The coherence length ?c along c-axis direction in (1 0 3)/(0 1 3) oriented YBCO superconductor thin films has been evaluated from the temperature dependence of current-voltage (I-V) characteristics of micro-bridges in the framework of a model taking in account thermally activated magnetic flux creep in the intrinsic potential of the layered structure of the superconductor. The coherence length gradually increased from the initial value ?c = 0.14 nm to ?c = 0.33 nm in the sample subjected to subsequent annealing steps performed in air at increasing temperatures from a range Ta = 190-275 deg. C. Structural modifications of deoxygenated samples were monitored by micro-Raman spectroscopy. The critical temperature Tc slightly increases after the initial annealing steps while a significant Tc decrease has been observed after Ta = 275 deg. C stage accompanied by appearance of the tetragonal phase in the crystal structure

106

Coherence length in deoxygenated (1 0 3)/(0 1 3) oriented YBCO superconductor films  

Science.gov (United States)

The coherence length ?c along c-axis direction in (1 0 3)/(0 1 3) oriented YBCO superconductor thin films has been evaluated from the temperature dependence of current-voltage ( I- V) characteristics of micro-bridges in the framework of a model taking in account thermally activated magnetic flux creep in the intrinsic potential of the layered structure of the superconductor. The coherence length gradually increased from the initial value ?c = 0.14 nm to ?c = 0.33 nm in the sample subjected to subsequent annealing steps performed in air at increasing temperatures from a range Ta = 190-275 C. Structural modifications of deoxygenated samples were monitored by micro-Raman spectroscopy. The critical temperature Tc slightly increases after the initial annealing steps while a significant Tc decrease has been observed after Ta = 275 C stage accompanied by appearance of the tetragonal phase in the crystal structure.

Camerlingo, Carlo; Jung, Grzegorz

2007-09-01

107

Controlled air pyrolysis incinerator  

International Nuclear Information System (INIS)

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

108

Pine Pyrolysis Vapor Phase Upgrading Over ZSM-5 Catalyst: Effect of Temperature, Hot Gas Filtration, and Hydrogen Donor Molecule on the Rate of Deactivation of Catalyst  

Energy Technology Data Exchange (ETDEWEB)

The conversion of primary vapors from pine pyrolysis over a ZSM-5 catalyst was characterized using a micro-reactor coupled to a molecular beam mass spectrometer (MBMS) to allow on-line measurement of the upgraded vapors. This micro-reacor-MBMS system was used to investigate the effects of hot gas filtration, temperature and hydrogen donor molecules on the rate of deactivation of the UPV2 catalyst. Our results show that the life of catalyst is significantly improved by using better filtration. Temperature had an effect on both product distribution and catalyst deactivation. The hydrogen donor molecules (HDM) used in this study show better reduction in catalyst deactivation rates at high temperatures.

Mukarakate, C.; Zhang, X.; Nimlos, M.; Robichaud, D.; Donohoe, B.

2013-01-01

109

Pyrolysis processing for solid waste resource recovery  

Science.gov (United States)

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

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

2007-01-01

110

Pyrolysis process for producing fuel gas  

Science.gov (United States)

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

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

2007-01-01

111

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

112

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

International Nuclear Information System (INIS)

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

113

Toxicity of pyrolysis gases from polyether sulfone  

Science.gov (United States)

A sample of polyether sulfone was evaluated for toxicity of pyrolysis gases, using the toxicity screening test method developed at the University of San Francisco. Animal response times were relatively short at pyrolysis temperatures of 600 to 800 C, with death occurring within 6 min. The principal toxicant appeared to be a compound other than carbon monoxide.

Hilado, C. J.; Olcomendy, E. M.

1979-01-01

114

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

International Nuclear Information System (INIS)

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

115

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-01-15

116

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

DEFF Research Database (Denmark)

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

Hu, Yang; Jensen, Jens Oluf

2014-01-01

117

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

2013-04-01

118

Eosin Y-sensitized graphitic carbon nitride fabricated by heating urea for visible light photocatalytic hydrogen evolution: the effect of the pyrolysis temperature of urea.  

Science.gov (United States)

Graphitic carbon nitride (g-C3N4) was prepared by pyrolysis of urea at different temperatures (450-650 C), and characterized by thermogravimetric and differential thermal analysis (TG-DTA), elemental analysis (C/H/N), X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (DRS), Brunauer-Emmett-Teller (BET) analysis, Fourier transform-infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL) spectra. The samples prepared at low temperatures (450 and 500 C) are a mixture of g-C3N4 and impurities, whereas the samples prepared at high temperatures (550, 600 and 650 C) should be g-C3N4 (polymeric carbon nitride). The polymerization degree of g-C3N4 for the prepared samples increases to a maximum at 600 C with increasing pyrolysis temperature and then decreases, whereas the defect concentration changes conversely, that is, g-C3N4 prepared at 600 C has the lowest defect concentration. Using Eosin Y (EY) and the prepared sample as the sensitizer and the matrix, respectively, the photocatalytic activity for hydrogen evolution from aqueous triethanolamine solution was investigated. The g-C3N4 prepared at 600 C exhibits the highest sensitization activity. Under optimum conditions (1.25 10(-5) mol L(-1) EY and 7.0 wt% Pt), the maximal apparent quantum yield of EY-sensitized g-C3N4 prepared at 600 C for hydrogen evolution is 18.8%. The highest activity can be attributed to the pure composition, the higher dye adsorption amount and the lowest defect concentration. PMID:23591628

Xu, Junying; Li, Yuexiang; Peng, Shaoqin; Lu, Gongxuan; Li, Shuben

2013-05-28

119

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

Directory of Open Access Journals (Sweden)

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

Rafia Azmat

2011-07-01

120

Deoxygenation method of reprocessed radioactive off-gas  

International Nuclear Information System (INIS)

Purpose: To eliminate the generation of iodine compounds and to improve recovery efficiency by terminating the operation prior to inactivation of the catalyst and by processing the heated catalyst with acidic gas. Method: When radioactive rare gas from the nuclear fuel reprocessing off-gas is to be recovered by the liquefaction distilling method, in the deoxygenation operation in pre-processing, operation is terminated when the charged catalyst in the oxyhydrogen reaction becomes inert due to the adhesion of iodine compounds and the catalysts is treated with heated acidic gas evaporating and removing the iodine compounds and the deoxygenation processing is resumed. Since this method provides an easy means of recovering the catalyst, if the catalyst recovery processing is performed periodically, efficiency of the oxyhydrogen reaction can be maintained at a high level over prolonged periods. Furthermore, iodine in the gasseous waste generated in the catalysts recovery processing can also be removed thus preventing environmental pollution from the recovered gasseous waste. (Takahashi, M.)

 
 
 
 
121

A calcinations temperature effect on La0.67Ca0.33MnO3 nanoparticle using simple citrate pyrolysis process  

International Nuclear Information System (INIS)

A new route to synthesize nanosized crystalline of La0.67Ca0.33MnO3 perovskite type complex oxides by simple citrate pyrolysis process using a metal salts, La, Ca, Mn as starting materials. To obtain the LCMO nanoparticles the precursor is carried out at calcinations temperature of 500 deg C, 600 deg C, 700 deg C, 800 deg C for all very short time only 60 minutes. The synthesized LCMO nanoparticles were characterized by powder XRD, FTIR, TGA/DTA, SEM. The precursor could be completely decomposed into complex oxide at temperature below 500 deg C according to the TGA/DTA results. XRD demonstrates that the decomposed species is composed of perovskite-type structure at calcinations temperature of 600 deg C for 60 minutes. The crystalline size that depends on the calcinations temperature of the precursor is a range of 11-22 nm as determined by Scherrer formula. All the prepared samples have high purity perovskite structure which is orthorhombic. The chemical bonds were identified by the measurements of Infrared IR transmission spectra carried out with powder samples in which KBr is used as a carrier. The IR spectra revealed that streaking and bending modes influenced by calcinations temperature. Morphology and grain size were studied through Scanning electron microscopy. When increase calcinations temperatures imply a growth of the particles. (author)

122

Optimization of multi-stage pyrolysis  

International Nuclear Information System (INIS)

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

123

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin  

International Nuclear Information System (INIS)

ng 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

124

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

Science.gov (United States)

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

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

2014-09-01

125

Room temperature electroluminescence from the n-ZnMgO/ZnO/p-ZnMgO heterojunction device grown by ultrasonic spray pyrolysis  

Science.gov (United States)

The heterojunction light-emitting diode with n-Zn 0.8Mg 0.2O/ZnO/p-Zn 0.8Mg 0.2O structure was grown on single-crystal GaAs(1 0 0) substrate by a simple process of ultrasonic spray pyrolysis. The p-type Zn 0.8Mg 0.2O layer was obtained by N-In codoping. A distinct visible electroluminescence with a dominant emission peak centered at 450 nm was observed at room temperature from the heterojunction structure under forward bias conditions. The origin of electroluminescence emission was supposed to be attributed to a radiative recombination through deep-level defects in the ZnO active layer. The result reported here provides convincing evidence that ZnO based light-emitting devices can be realized at extremely low cost.

Bian, Jiming; Liu, Weifeng; Liang, Hongwei; Hu, Lizhong; Sun, Jingchang; Luo, Yingmin; Du, Guotong

2006-10-01

126

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

Science.gov (United States)

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

Kinoshita, Takuya; Furuyabu, Takamitsu; Adachi, Motoaki

2014-10-01

127

Modeling CFB biomass pyrolysis reactors  

International Nuclear Information System (INIS)

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 51010 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

128

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

Directory of Open Access Journals (Sweden)

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

2012-12-01

129

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

130

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 400C for one sample and at 500C 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

2011-03-01

131

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

132

Fixed bed pyrolysis of the rapeseed cake  

Energy Technology Data Exchange (ETDEWEB)

The fixed bed atmospheric pressure pyrolysis and nitrogen swept pyrolysis of the rapeseed cake obtained from cold extraction press have been investigated. Experiments were performed in the Heinze retort at a 7{sup o}C min{sup -1} heating rate, with a 500{sup o}C final temperature varying sweep gas velocity (50, 100, 150, 200, 250, 300 cm{sup 3} min{sup -1}) under nitrogen atmosphere. Liquid, gas, and char yields were determined, pyrolysis conversion was calculated, and liquid, char, and gas products were presented as an environmentally friendly fuel candidate. (author)

Sensoz, S.; Yorgun, S.; Angin, D.; Culcuoglu, E.; Ozcimen, D.; Karaosmanoglu, F.

2001-12-15

133

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

International Nuclear Information System (INIS)

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

134

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-01-05

135

Effects of torrefaction and densification on switchgrass pyrolysis products  

Energy Technology Data Exchange (ETDEWEB)

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

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

2014-10-01

136

Phenomenological models of cellulose pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Using yields vs. residence time and temperature from 50 to 1000 ms and 650-900{sup o}C, measured with the ultra pyrolysis system at the University of Western Ontario (UWO) we established an approximate total gaseous yield function Y (t,T). With UWO data, we also establish approximate correlations between individual gaseous yields (CO, CO{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 6} and C{sub 3}H{sub 6}) and the total gaseous yield that could be used to give Y{sub i}(t,T) for individual gases. We further extend Y(t,T) using shock tube pyrolysis measurements from 0.3 to 2 ms and 900 to 2100{sup o}C made at Kansas State University (KSU). In doing so, we develop a global decay model that gives analytical time and temperature dependencies for cellulose, activated cellulose, tar, prompt total gas and late total gas. We next examine the impact of heating rates and transfer upon pyrolysis of cellulose using slow pyrolysis data obtained by thermogravimetric analysis at the Colarado School of Mines (CSM). In this effort, we first develop an accurate general relationship for Boltzmann integrals. Then using an analytically convenient Arrhenius reaction rate (ARR) we examine data at varying heating rates and with three Biot numbers. We find some phenomenological analytical relationships giving ARR parameter dependencies on heating rate and particle size that appear indicative of heat transfer impacts. If adequate data becomes available these relationships might be applied to hemicellulose and lignin. Then the pyrolysis rates of any plant species might be predicted in terms of the pyrolytic characteristics of their cellulose, hemicellulose and lignin components. (Author)

Green, A.E.S.; Zanardi, M.A.; Mullin, J.P. [Florida Univ., Gainesville, FL (United States). Combustion Lab.]|[Florida Univ., Gainesville, FL (United States). Dept. of Mechanical Engineering

1997-12-31

137

Coherence length in deoxygenated (1 0 3)/(0 1 3) oriented YBCO superconductor films  

Energy Technology Data Exchange (ETDEWEB)

The coherence length {xi}{sub c} along c-axis direction in (1 0 3)/(0 1 3) oriented YBCO superconductor thin films has been evaluated from the temperature dependence of current-voltage (I-V) characteristics of micro-bridges in the framework of a model taking in account thermally activated magnetic flux creep in the intrinsic potential of the layered structure of the superconductor. The coherence length gradually increased from the initial value {xi}{sub c} = 0.14 nm to {xi}{sub c} = 0.33 nm in the sample subjected to subsequent annealing steps performed in air at increasing temperatures from a range T{sub a} = 190-275 deg. C. Structural modifications of deoxygenated samples were monitored by micro-Raman spectroscopy. The critical temperature T{sub c} slightly increases after the initial annealing steps while a significant T{sub c} decrease has been observed after T{sub a} = 275 deg. C stage accompanied by appearance of the tetragonal phase in the crystal structure.

Camerlingo, Carlo [Consiglio Nazionale delle Ricerche, Istituto di Cibernetica ' E. Caianiello' , Via Campi Flegrei 34, 80078 Pozzuoli (Italy)], E-mail: c.camerlingo@cib.na.cnr.it; Jung, Grzegorz [Department of Physics, Ben Gurion University of Negev, 84105 Beer Sheva (Israel)

2007-09-01

138

An oxygenase that forms and deoxygenates toxic epoxide.  

Science.gov (United States)

Catabolism may give rise to toxic intermediates that compromise cell vitality, such as epoxide formation in the recently elucidated and apparently universal bacterial coenzyme A (CoA)-dependent degradation of phenylacetic acid. This compound is central to the catabolism of a variety of aromatics, such as phenylalanine, lignin-related compounds or environmental contaminants. The key phenylacetyl-CoA monooxygenase (epoxidase) of the pathway, PaaABCE, is also connected to the production of various primary and secondary metabolites, as well as to the virulence of certain pathogens. However, the enzyme complex has so far not been investigated in detail. Here we characterize the bacterial multicomponent monooxygenase PaaABCE that, surprisingly, not only transforms phenylacetyl-CoA into its ring-1,2-epoxide, but also mediates the NADPH-dependent removal of the epoxide oxygen, regenerating phenylacetyl-CoA with formation of water. We provide evidence for a catalytic di-iron centre that is probably the key to the unprecedented deoxygenation of an organic compound by an oxygenase. Presumably, the bifunctionality is vital to avoid toxic intracellular epoxide levels if the subsequent catabolic steps are impeded. Our data suggest that detoxification is assisted by two thioesterases (PaaI and PaaY) forming non-reactive breakdown products. Hence, PaaABCE may harbour an intrinsic escape mechanism from its own toxic product and represents the archetype of a bifunctional oxygenase/deoxygenase. Analogous reactions may possibly be catalysed by other di-iron epoxidases. PMID:22398448

Teufel, Robin; Friedrich, Thorsten; Fuchs, Georg

2012-03-15

139

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.

140

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

Science.gov (United States)

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

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

2013-11-01

 
 
 
 
141

Volatile Analysis by Pyrolysis of Regolith in the 2011 D-RATS Field Test  

Science.gov (United States)

The Volatile Analysis by Pyrolysis of Regolith (VAPoR) instrument is a compact vacuum pyrolysis mass spectrometer designed to detect volatiles released during high temperature (up to 1300C) heating of crushed or solid samples.

Malespin, C. A.; Glavin, D. P.; Ten Kate, I. L.; Franz, H. B.; Mumm, E.; Bleacher, J. E.; Rice, J. W.

2012-03-01

142

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

143

Fundamental Pyrolysis Studies  

Energy Technology Data Exchange (ETDEWEB)

Progress on the direct mass spectrometric sampling of pyrolysis products from wood and its constituents is described for the period from June 1982 to February 1983. A brief summary and references to detailed reports, of the qualitative demonstration of our approach to the study of the separated processes of primary and secondary pyrolysis is presented. Improvements and additions to the pyrolysis and data acquisition systems are discussed and typical results shown. Chief of these are a heated-grid pyrolysis system for controlled primary pyrolysis and a sheathed flame arrangement for secondary cracking studies. Qualitative results of the secondary cracking of cellulose, lignin, and wood are shown as are comparisons with the literature for the pyrolysis spectra of cellulose, lignin, and levoglucosan. 'Fingerprints' for a number of materials are shown, with spectra taken under carefully controlled conditions so that sensitivity calibrations for different compounds, now being determined, can be applied.

Milne, T. A.; Evans, R. J.; Soltys, M. N.

1983-03-01

144

PYROLYSIS OF TOBACCO RESIDUE. PART 2: CATALYTIC  

Directory of Open Access Journals (Sweden)

Full Text Available The pyrolysis of tobacco residue in the presence of metal oxides and metal chlorides was investigated at 300, 400, and 500 C. Catalysts used were Al2O3, Fe2O3, AlCl3, and SnCl4 in concentrations from 1 up to 5 wt% of the tobacco residue feedstock. The amount of catalysts and the pyrolysis temperature had significant effect on both product distributions and bio-oil composition. The catalytic effect was dominant at the lowest temperature (300 C. The pyrolysis temperature was decreased by 200 C compared to the thermal run. Bio-oil contained a large variety of compounds. Nicotine, which is very stable until temperatures in excess of 600 C, could be degraded at the lowest temperature by using 1 wt% of AlCl3 and 1 wt% of Fe2O3.

Mehmet K. Akalin

2011-04-01

145

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)

146

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

147

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

Directory of Open Access Journals (Sweden)

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

Kazuo Oguri

2008-12-01

148

PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST  

Directory of Open Access Journals (Sweden)

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

Xian-Hua Wang

2009-08-01

149

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-07-01

150

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

International Nuclear Information System (INIS)

A detailed analysis of iron-containing phases in multiwall carbon nanotube (MWCNT) powder was carried out. The MWCNTs were produced by camphor/ferrocene and purified by high temperature annealing in an oxygen-free atmosphere (N2 or VC). Thermogravimetric analysis, Moessbauer spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy enabled the evaluation of the residual iron in MWCNTs after purification. The VC treatments provided MWCNTs with a purity degree higher than 99%. Moreover, Raman spectroscopy revealed a significant improvement in graphitic ordering after thermal annealing. A brief description of the mechanism of iron removal was included. We highlight the mobility of iron atoms through graphitic sheets and the large contact angle of iron clusters formed on MWCNT surfaces at high temperatures.

151

FAST PYROLYSIS OF LIGNINS  

Directory of Open Access Journals (Sweden)

Full Text Available Three lignins: Indulin AT, LignoboostTM, and Acetocell lignin, were characterized and pyrolyzed in a continuous-fed fast pyrolysis process. The physical and chemical properties of the lignins included chemical composition, heat content, ash, and water content. The distributed activation energy model (DAEM was used to describe the pyrolysis of each lignin. Activation energy distributions of each lignin were quite different and generally covered a broad range of energies, typically found in lignins. Process yields for initial continuous-fed fast pyrolysis experiments are reported. Bio-oil yield was low, ranging from 16 to 22%. Under the fast pyrolysis conditions used, the Indulin AT and LignoboostTM lignin yielded slightly more liquid product than the Acetocell lignin. Lignin kinetic parameters and chemical composition vary considerably and fast pyrolysis processes must be specified for each type of lignin.

Sedat Beis

2010-05-01

152

Fast Pyrolysis of Poplar Using a Captive Sample Reactor: Effects of Inorganic Salts on Primary Pyrolysis Products  

Energy Technology Data Exchange (ETDEWEB)

We have constructed a captive sample reactor (CSR) to study fast pyrolysis of biomass. The reactor uses a stainless steel wire mesh to surround biomass materials with an isothermal environment by independent controlling of heating rates and pyrolysis temperatures. The vapors produced during pyrolysis are immediately entrained and transported in He carrier gas to a molecular beam mass spectrometer (MBMS). Formation of secondary products is minimized by rapidly quenching the sample support with liquid nitrogen. A range of alkali and alkaline earth metal (AAEM) and transition metal salts were tested to study their effect on composition of primary pyrolysis products. Multivariate curve resolution (MCR) analysis of the MBMS data shows that transition metal salts enhance pyrolysis of carbohydrates and AAEM salts enhances pyrolysis of lignin. This was supported by performing similar separate studies on cellulose, hemicellulose and extracted lignin. The effect of salts on char formation is also discussed.

Mukarakate, C.; Robichaud, D.; Donohoe, B.; Jarvis, M.; Mino, K.; Bahng, M. K.; Nimlos, M.

2012-01-01

153

Characterization of pyrolysis products from a biodiesel phenolic urethane binder.  

Science.gov (United States)

Analytical pyrolysis was conducted to identify and quantify the major pyrolysis products of a biodiesel phenolic urethane binder as a function of temperature. This biodiesel binder has been used in U.S. foundries recently to replace conventional phenolic urethane binders for making sand cores. Flash pyrolysis and thermogravimetric analytical (TGA) slow pyrolysis were conducted for the core samples to simulate some key features of the heating conditions that the core binders would experience during metal casting. Pyrolysis products from flash and TGA pyrolysis were analyzed with gas chromatography-mass spectrometry/flame ionization detection/thermal conductivity detection. The evolution profiles of the pyrolysis products during TGA slow pyrolysis were also monitored via thermogravimetry-mass spectrometry (TG-MS). The combination of TG-MS and TGA pyrolysis emission data facilitated a quantification of gaseous pyrolysis products of the biodiesel binder as a function of temperature. The major monitored carbonaceous pyrolysis products of the biodiesel binder included CO, CO2, CH4, and a variety of methyl esters such as dimethyl glutarate, dimethyl adipate, and methyl oleate. These latter species were the components of the biodiesel binder's solvent Pyrolysis of the biodiesel binder also generated a variety of hazardous air pollutants listed by the U.S. EPA, with benzene, toluene, xylene, phenol, and cresols being the prominent species. A considerable fraction of the binder's released mass did not appear as exhausted volatile carbonaceous species, but rather recondensed before they exhausted from the TGA. This represented mass that could likewise recondense within a green sand molding system during full-scale operations, as an environmentally favorable containment of air emissions. PMID:19350935

Wang, Yujue; Cannon, Fred S; Salama, Magda; Fonseca, Dania A; Giese, Scott

2009-03-01

154

Thermogravimetric Analysis and Global Kinetics of Segregated MSW Pyrolysis  

Directory of Open Access Journals (Sweden)

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

Dwi Aries Himawanto

2011-12-01

155

Gold Nanoparticle-Catalyzed Environmentally Benign Deoxygenation of Epoxides to Alkenes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 reu...

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

2011-01-01

156

Pyrolysis of flame retardant brominated polyester composites.  

Science.gov (United States)

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

Cunliffe, A M; Williams, P T

2004-12-01

157

Modelling of pyrolysis of large wood particles.  

Science.gov (United States)

A fully transient mathematical model has been developed to describe the pyrolysis of large biomass particles. The kinetic model consists of both primary and secondary reactions. The heat transfer model includes conductive and internal convection within the particle and convective and radiative heat transfer between the external surface and the bulk. An implicit Finite Volume Method (FVM) with Tridiagonal Matrix Algorithm (TDMA) is employed to solve the energy conservation equation. Experimental investigations are carried out for wood fines and large wood cylinder and sphere in an electrically heated furnace under inert atmosphere. The model predictions for temperature and mass loss histories are in excellent agreement with experimental results. The effect of internal convection and particle shrinkage on pyrolysis behaviour is investigated and found to be significant. Finally, simulation studies are carried out to analyze the effect of bulk temperature and particle size on total pyrolysis time and the final yield of char. PMID:19231172

Sadhukhan, Anup Kumar; Gupta, Parthapratim; Saha, Ranajit Kumar

2009-06-01

158

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

159

CHARACTERISTICS OF CORN STALK HEMICELLULOSE PYROLYSIS IN A TUBULAR REACTOR  

Directory of Open Access Journals (Sweden)

Full Text Available Pyrolysis characteristics of corn stalk hemicellulose were investigated in a tubular reactor at different temperatures, with focus mainly on the releasing profiles and forming behaviors of pyrolysis products (gas, char, and tar. The products obtained were further identified using various approaches (including GC, SEM, and GC-MS to understand the influence of temperature on product properties and compositions. It was found that the devolatilization of hemicellulose mainly occurred at low temperatures

Gao-Jin Lv

2010-08-01

160

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

 
 
 
 
161

Preconversion catalytic deoxygenation of phenolic functional groups. Final technical report, September 1, 1989--August 31, 1992  

Energy Technology Data Exchange (ETDEWEB)

Several new catalysts for phenol deoxygenation by CO were developed in our laboratories during the grant period. The deoxygenation of phenols by CO represents a.novel approach to the upgrading of coal liquids. The deoxygenation of phenols by CO is thermodynamically more favorable and potentially less expensive than current phenol hydrodeoxygenation (HDO) methods. The reaction was not known to be kinetically feasible until our recent discovery of appropriate catalysts. The catalyst precursor [Ir(triphos)({eta}{sup 4{minus}}C{sub 8}H{sub 12})][C1] was found to catalytically deoxygenate phenol and p-cresol. Reactions were conducted with varying amounts of AR-OH (Ar = C{sub 6}H{sub 5}, p-Me-C{sub 6}H{sub 4}), NaO-Ar, and catalyst precursor. In some reactions, triethyl amine was substituted for NaO-Ar to deprotonate the ArOH. All reactions took place at 55{degrees}C so that AR-OH was the solvent One atmosphere of CO was introduced into each reactor. Periodically, gasses were sampled by gas chromatography (GC) to monitor the disappearance of CO and the appearance of CO{sub 2}. After the amount of CO{sub 2} had reached a plateau, organic products were distilled from the reaction mixture and analyzed by high pressure liquid chromatography (HPLC). Significant quantities of arene (benzene or toluene) were obtained. These results are general. Initial use of phenol results in only benzene. Initial use of p-cresol results in only toluene. Control reactions eliminate the catalyst precursor as the source Of CO{sub 2} or arene. No evidence is obtained for diarylcarbonate formation. HPLC and GC data from consistently demonstrated that toluene and CO{sub 2} were the only products obtained from the deoxygenation of p-cresol by CO. These results were extended to a series of variously substituted phenolic and naptholic substrates related to those found in coal liquids.

Kubiak, C.P.

1992-12-31

162

Catalytic pyrolysis of biomass by novel nanostructured catalysts  

Science.gov (United States)

Nanostructured catalysts were successfully prepared by acidification of diatomites and the regeneration of used FCC catalysts. The obtained samples were characterized by IR, XRD, SEM, EDX, MAS-NMR (27Al and 29Si), NH3-TPD and tested in catalytic pyrolysis of biomass (rice straw). The results showed that the similar bio-oil yield of 41,4% can be obtained by pyrolysis in presence of catalysts at 450C as compared to that of the pyrolysis without catalyst at 550C. The bio-oil yield reached a maximum of 42,55 % at the pyrolysis temperature of 500C with catalytic content of 20%. Moreover, by catalytic pyrolysis, bio-oil quality was better as reflected in higher ratio of H/C, lower ratio of O/C. This clearly indicated high application potential of these new nanostructured catalysts in the production of bio-oil with low oxygenated compounds.

Dang, Phuong T.; Le, Hy G.; Pham, Giang T. T.; Vu, Hng T. M.; Nguyen, Kien T.; Dao, Canh D.; Le, Giang H.; Hoang, Thuy T. T.; Tran, Hoa T. K.; Nguyen, Quang K.; Vu, Tuan A.

2013-12-01

163

Syngas yield during pyrolysis and steam gasification of paper  

International Nuclear Information System (INIS)

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

164

Microwave-assisted pyrolysis of biomass for liquid biofuels production  

DEFF Research Database (Denmark)

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

Yin, Chungen

2012-01-01

165

Plasma emission spectral detection for pyrolysis-gas chromatography  

Science.gov (United States)

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

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

166

Catalytic pyrolysis-GC/MS of lignin from several sources  

Energy Technology Data Exchange (ETDEWEB)

Lignin from four different sources, extracted by various methods, were pyrolyzed at 650 C using analytical pyrolysis methods (Py-GC/MS). Pyrolysis was carried out in the absence and presence of two heterogeneous catalysts, an acidic zeolite (HZSM-5) catalyst and a mixed metal oxide catalyst (CoO/MoO{sub 3}). Non-catalytic Py-GC/MS was used to identify the lignin as characterized by their H-, G- or S-lignin makeup and also served as the control basis to evaluate the effect of the said catalysts on the production of aromatic hydrocarbons from these lignin sources. Experiments show that the selectivity to particular aromatic hydrocarbons varies with the composition of the lignin for both catalysts. The major pathway for hydrocarbon production over HZSM-5 is likely increased depolymerization efficiency that releases and converts the aliphatic linkers of lignin to olefins followed by aromatization. Simple phenols produced from the deconstruction of the lignin polymer are likely to be a source of zeolite deactivation. The CoO/MoO{sub 3} is likely to produce aromatic hydrocarbons through a direct deoxygenation of methoxyphenol units. (author)

Mullen, Charles A.; Boateng, Akwasi A. [Eastern Regional Research Center, Agricultural Research Service, U. S. Department of Agriculture, 600 E. Mermaid Lane, Wyndmoor, PA 19038 (United States)

2010-11-15

167

Hydrothermal deoxygenation of triglycerides over Pd/C aided by in situ hydrogen production from glycerol reforming.  

Science.gov (United States)

A one-pot catalytic hydrolysis-deoxygenation reaction for the conversion of unsaturated triglycerides and free fatty acids to linear paraffins and olefins is reported. The hydrothermal deoxygenation reactions are performed in hot compressed water at 250 C over a Pd/C catalyst in the absence of external H2 . We show that aqueous-phase reforming (APR) of glycerol and subsequent water-gas-shift reaction result in the in situ formation of H2 . While this has a significant positive effect on the deoxygenation activity, the product selectivity towards high-value, long-chain olefins remains high. PMID:24596129

Hollak, Stefan A W; Arins, Maxim A; de Jong, Krijn P; van Es, Daan S

2014-04-01

168

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

International Nuclear Information System (INIS)

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

169

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

2011-01-01

170

PYROLYSIS AND COMBUSTION OF SCRAP TIRE  

Directory of Open Access Journals (Sweden)

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

?. Jelemensk

2006-02-01

171

Vacuum pyrolysis of swine manure : biochar production and characteristics  

Energy Technology Data Exchange (ETDEWEB)

Quebec accounts for nearly 25 per cent of swine production in Canada. The issue of swine manure is addressed through land spreading and conversion into fertilizer. However, current regulations restrict the use of swine manure as fertilizer on most farmlands due to the problem of surplus phosphorus and nitrogen. Although many technologies exist to separate phosphorus and nitrogen from the organic-rich dry matter in swine manure, about 40 per cent of the treated waste matter must still be disposed in an environmentally sound manner. This study investigated the technical feasibility of pretreating the swine manure solids into biofuels on a farm-scale basis using vacuum pyrolysis process. A custom built stainless steel pressure vessel was used to carry out pyrolysis reaction of swine manure biomass at a temperature range between 200 to 600 degrees C under vacuum. The pyrolytic vapour was condensed in 2 glass condensers in series. The biochar was collected directly from the pyrolysis vessel following completion of the pyrolysis batch. The non condensable vapour and gases were considered as losses. Biochar, bio-oil, an aqueous phase and a gas mixture were the 4 products of the pyrolysis process. A thermogravimetric analysis of the swine manure samples was conducted before the pyrolysis tests. The study showed that 238 degrees C is the optimal pyrolysis temperature for biochar production.

Verma, M. [Inst. de recherche et de developpement en agroenvironnement Inc., Quebec City, PQ (Canada); Centre de recherche industrielle du Quebec, Quebec City, PQ (Canada); Godbout, S.; Larouche, J.P.; Lemay, S.P.; Pelletier, F. [Inst. de recherche et de developpement en agroenvironnement Inc., Quebec City, PQ (Canada); Solomatnikova, O. [Centre de recherche industrielle du Quebec, Quebec City, PQ (Canada); Brar, S.K. [Inst. national de la recherche scientifique, eau, terre et environnement, Quebec City, PQ (Canada)

2010-07-01

172

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(OH16] (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.

Kiyotomi Kaneda

2011-09-01

173

A Membrane De-Oxygenator for the Study of Anoxic Processes  

DEFF Research Database (Denmark)

A membrane reactor for the elimination of oxygen in an anoxic medium for microbial growth has been studied. The reactor consists of a reservoir containing a solution of sulfite and cobalt salt where silicone tubing, through which the medium flows, is immersed. Silicone is highly permeable to gases, so oxygen diffuses through the silicone membrane and is absorbed in the sulfite solution. The maximum oxygen removal rate was 1.1 g m?2 d?1 at 15C. The advantage of this de-oxygenator is its low cost and the ease with which it can be handled. A calculation method is discussed in relation to the design of the membrane de-oxygenator.

Arcangeli, Jean-Pierre; Arvin, Erik

1995-01-01

174

Deoxygenation alters bacterial diversity and community composition in the oceans largest oxygen minimum zone  

Science.gov (United States)

Oceanic oxygen minimum zones (OMZs) have a central role in biogeochemical cycles and are expanding as a consequence of climate change, yet how deoxygenation will affect the microbial communities that control these cycles is unclear. Here we sample across dissolved oxygen gradients in the oceans largest OMZ and show that bacterial richness displays a unimodal pattern with decreasing dissolved oxygen, reaching maximum values on the edge of the OMZ and decreasing within it. Rare groups on the OMZ margin are abundant at lower dissolved oxygen concentrations, including sulphur-cycling Chromatiales, for which 16S rRNA was amplified from extracted RNA. Microbial species distribution models accurately replicate community patterns based on multivariate environmental data, demonstrate likely changes in distributions and diversity in the eastern tropical North Pacific Ocean, and highlight the sensitivity of key bacterial groups to deoxygenation. Through these mechanisms, OMZ expansion may alter microbial composition, competition, diversity and function, all of which have implications for biogeochemical cycling in OMZs.

Beman, J. Michael; Carolan, Molly T.

2013-10-01

175

Unprecedented deoxygenation at C-7 of the ansamitocin core during mutasynthetic biotransformations  

Directory of Open Access Journals (Sweden)

Full Text Available We describe the unprecedented formation of six ansamitocin derivatives that are deoxygenated at C-7 of the ansamitocin core, obtained during fermentation experiments by employing a variety of Actinosynnema pretiosum mutants and mutasynthetic approaches. We suggest that the formation of these derivatives is based on elimination at C-7/C-8 followed by reduction(s of the intermediate enone. In bioactivity tests, only ansamitocin derivatives bearing an ester side chain at C-3 showed strong antiproliferative activity.

Tobias Knobloch

2012-06-01

176

Solid waste utilization: pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

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

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

1977-08-01

177

Biomass pyrolysis for chemicals  

Energy Technology Data Exchange (ETDEWEB)

The problems associated with the use of fossil fuels demand a transition to renewable sources (sun, wind, water, geothermal, biomass) for materials and energy where biomass provides the only renewable source for chemicals. In a biorefinery, biomass is converted via different technologies into heat, power and various products. Here, pyrolysis (thermal degradation without added oxygen) of lignocellulosic biomass can play an important role, because it leads to an array of useful chemicals. Examples are furfural and acetic acid from hemicellulose, levoglucosan from cellulose and phenols and biochar from lignin. Since the three major biomass polymers hemicellulose, cellulose and lignin possess dissimilar thermal stabilities and reactivities, type and amount of degradation products are tunable by proper selection of the pyrolysis conditions. To determine if step-wise pyrolysis would be suitable for the production of chemicals, staged degasification of lignocellulosic biomass was studied. Due to limited yields, a hot pressurized water pre-treatment (aquathermolysis) followed by pyrolysis was subsequently developed as an improved version of a staged approach to produce furfural and levoglucosan from the carbohydrate fraction of the biomass. Lignin is the only renewable source for aromatic chemicals. Lignocellulosic biorefineries for bio-ethanol produce lignin as major by-product. The pyrolysis of side-streams into valuable chemicals is of prime importance for a profitable biorefinery. To determine the added-value of lignin side-streams other than their use as fuel for power, application research including techno-economic analysis is required. In this thesis, the pyrolytic valorisation of lignin into phenols and biochar was investigated and proven possible.

De Wild, P.

2011-07-15

178

Characterization of products from the pyrolysis of rapeseed oil cake.  

Science.gov (United States)

The main aim of this study was to investigate the composition of products from the pyrolysis of rapeseed oil cake in a fixed bed reactor at 400, 450, 500, 700 and 900 degrees C. The gas products mainly consisted of CO(2), CO, CH(4) and H(2)S at 500 degrees C. Empirical formula of bio-oil from the pyrolysis of rapeseed oil cake was CH(1.59)O(0.16)N(0.116)S(0.003) for 500 degrees C. Bio-oils mainly contained oleic acid, 1H-indole, 2,3,5-trimethoxy toluene, toluene, (Z)-9-octadecanamide, psoralene, phenol and phenol derivatives at all pyrolysis temperatures. Both non-aromatic and aromatic hydrocarbon compounds were determined in water phase of liquid product by Headspace-GC analysis. The heating values of bio-chars were found to be similar (24MJkg(-1)) at all pyrolysis temperatures. PMID:18511268

Ucar, Suat; Ozkan, Ahmet R

2008-12-01

179

Muscle deoxygenation of upper-limb muscles during progressive arm-cranking exercise.  

Science.gov (United States)

The purpose of this study was to determine which upper-limb muscle exhibits the greatest change in muscle deoxygenation during arm-cranking exercise (ACE). We hypothesized that the biceps brachii (BB) would show the greatest change in muscle deoxygenation during progressive ACE to exhaustion relative to triceps brachii (TR), brachioradialis (BR), and anterior deltoid (AD). Healthy young men (n = 11; age = 27 +/- 1 y; mean +/- SEM) performed an incremental ACE test to exhaustion. Near-infrared spectroscopy (NIRS) was used to monitor the relative concentration changes in oxy- (O2Hb), deoxy- (HHb), and total hemoglobin (Hbtot), as well as tissue oxygenation index (TOI) in each of the 4 muscles. During submaximal arm exercise, we found that changes to NIRS-derived measurements were not different between the 4 muscles studied (p > 0.05). At maximal exercise HHb was significantly higher in the BB compared with AD (p < 0.05). Relative to the other 3 muscles, BB exhibited the greatest decrease in O2Hb and TOI (p < 0.05). Our investigation provides two new and important findings: (i) during submaximal ACE the BB, TR, BR, and AD exhibit similar changes in muscle deoxygenation and (ii) during maximal ACE the BB exhibits the greatest change in intramuscular O2 status. PMID:18347677

Lusina, Sarah-Jane C; Warburton, Darren E R; Hatfield, Nicola G; Sheel, A William

2008-04-01

180

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

Directory of Open Access Journals (Sweden)

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

I. Adewumi

2005-01-01

 
 
 
 
181

Modification and implications of changes in electrochemical responses encountered when undertaking deoxygenation in ionic liquids.  

Science.gov (United States)

Physicochemical changes and substantially modified electrochemical behavior have been reported when ionic liquids are degassed with nitrogen. In conventional experiments in aqueous and organic media, degassing with N(2) is commonly used to remove the electroactive dissolved oxygen. However, in hydrophilic ionic liquid media, degassing with N(2) removes not only the dissolved oxygen but also a significant amount of the adventitious water present. Given the low viscosity of water, this in turn leads to a dramatic change of the viscosity of the degassed ionic liquid and hence mass transport properties that influence voltammetric responses. In the widely used and relatively viscous room temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF(4)) containing the redox probe tetracyanoquinodimethane (TCNQ) and 9% (v/v) deliberately added water, 1 h degassing with very dry N(2) under benchtop conditions results in a dramatic decrease of the TCNQ reduction current obtained under steady-state conditions at a 1 mum diameter microdisc electrode. This is reflected by a change of diffusion coefficient of TCNQ (D(TCNQ)) from 2.6 x 10(-7) to 4.6 x 10(-8) cm(2) s(-1). Karl Fischer titration measurements show that almost complete removal of the deliberately added 9% water is achieved by degassing under benchtop conditions. However, displacement of oxygen by nitrogen in the ionic liquid solution results in the decrease of electrochemical reduction current by 6%, implying that dissolved gases need not be inert with respect to solvent properties. Oxygen removal by placing the BMIMBF(4) ionic liquid in a nitrogen-filled glovebox or in a vacuum cell also simultaneously leads to removal of water and alteration of voltammetric data. This study highlights that (i) important physicochemical differences may arise upon addition or removal of a solute from viscous ionic liquids; (ii) degassing with dry nitrogen removes water as well as oxygen from ionic liquids, which may have implications on the viscosity and structure of the medium; (iii) particular caution must be exercised when deoxygenation is applied in ionic liquid media as part of the protocol used in electrochemical experiments to remove oxygen; (iv) gases such as oxygen, argon, and nitrogen dissolved in ionic liquids need not be innocent with respect to the properties of an ionic liquid. The use of vacuum based techniques to eliminate all volatile solutes, including water and oxygen, is advocated. PMID:20392069

Zhao, Chuan; Bond, Alan M; Compton, Richard G; O'Mahony, Aoife M; Rogers, Emma I

2010-05-01

182

[Structural identification of carboxylic esters by pyrolysis gas chromatography].  

Science.gov (United States)

A pyrolysis gas chromatographic method has been investigated for structural identification of carboxylic esters. The method can be applied to identify not only pure components, but also those separated by thin layer chromatography and scraped from the TLC plate without removing the adsorbent. The samples were pyrolyzed in tube furnace pyrolyzer at 500 degrees C (conventional pyrolysis) or were pyrolyzed at 550 degrees C after mixing with soda-lime powder (pyrolysis with soda-lime). Some esters such as iso-octyl palmitate, glycerol monostearate and diethyl phthalate were pyrolyzed. The pyrolysis products were identified by comparing with the known. The parent alcohols of monohydric and polyhydric alcohol esters can be determined respectively according to alcohols, alkenes produced on pyrolysis and dehydrated products of polyhydric alcohol at high temperature. The parent acids of monocarboxylic esters can be determined according to carboxylic acid produced on conventional pyrolysis or corresponding alkane formed from decarboxylation of parent acids on pyrolysis with soda-lime. For esters formed from dicarboxylic acids that can be dehydrated to produce five-, six-membered cyclic ketones or can be dehydrated and decarboxylated simultaneously to produce five-, six-membered cyclic acid anhydrides, parent acids can be determined according to corresponding cyclic ketones or cyclic acid anhydrides. This method is useful for identification of common carboxylic esters. When the compound or the component of the mixture was confirmed to contain ester-group by infra-red spectroscopy, PGC or TLC-PGC can be employed to make further identification. PMID:15739430

Liu, E; Chen, W

1997-01-01

183

Pitting corrosion in CVD SiC at 300 deg. C in deoxygenated high-purity water  

International Nuclear Information System (INIS)

SiC is a candidate for nuclear applications at elevated temperatures but has not been fully studied under typical light-water reactor operating conditions, such as moderate temperatures and high pressures. Coupons of high-purity chemical vapor deposited SiC were exposed to deoxygenated, pressurized water at 573 K and 10 MPa for up to 5400 h. Ceramographic examination of the exposed SiC surfaces revealed both embryonic and large, d > 300 ?m, pits on the surface after initial exposure for 4000 h. The pits were characterized using scanning electron microscopy for structure and chemistry analysis. Pit densities were also determined by standard counting methods. The chemical analysis revealed that the pits are associated with the formation of silica and subsequent loss of Si, which is expected due to several suggested reactions between SiC and water. Subsequent exposure under nominally identical water chemistry conditions for an additional 1400 h removed the pits and the samples exhibited general corrosion with measurable loss of Si from the surface

184

Experimental investigation of pyrolysis process of woody biomass mixture  

Science.gov (United States)

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

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

2014-06-01

185

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

International Nuclear Information System (INIS)

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

186

Volatile Analysis by Pyrolysis of Regolith for Planetary Resource Exploration  

Science.gov (United States)

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

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

2012-01-01

187

Analytical pyrolysis of copolymers  

Science.gov (United States)

In the first part of the paper, a survey is given of the present state of characterization and analysis of copolymers by pyrolysis with subsequent separation and analysis of the pyrolysate. Special attention is given to the mechanisms of thermal degradation of polymers and copolymers. Among the analytical methods, pyrolysis-mass spectrometry with field-ionization (Py-FIMS) as well as pyrolysis-gas chromatography (Py-GC) coupled with mass or FTIR spectrometry are most powerful. In the second part of the paper, our own results on the analysis of elastomers on the basis of random and block-type copolymers as well as polymer blends by Py-FIMS are reported. By the use of intensity ratios of monomer peaks together with the intensities of homo- and hybrid dimer and trimer fragments, different types of elastomers can be identified. Acrylic resins were investigated by Py-GC/dispersive i.r. and by Py-GC/FTIR. As expected, the latter method is much more sensitive. Compared with Py-FIMS, Py-GC/FTIR has the advantage of giving direct evidence of the chemical nature of the fragments. This is crucial when nothing is known of a system under consideration.

Hummel, D. O.; Dssel, H.-J.; Czybulka, Gina; Wenzel, N.; Holl, G.

188

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

189

Fixed-bed pyrolysis of rapeseed (Brassica napus L.)  

International Nuclear Information System (INIS)

Fixed-bed slow and fast pyrolysis experiments have been conducted on a sample of rapeseed. The experiments were performed in two different pyrolysis reactors, namely a fixed-bed Heinze and a well-swept fixed-bed tubular retort to investigate the effects of heating rate, pyrolysis temperature, particle size, sweep gas velocity on the pyrolysis product yields and chemical compositions. The maximum oil yield of 51.7% was obtained in the Heinze reactor 550 deg. C, with a particle size range of +0.6-1.8 mm (sweep gas 100 cm3 min-1 N2) at a heating rate of 30 deg. C min-1. In the well-swept fixed-bed reactor, the maximum oil yield of 68% was obtained at a heating rate of 300 deg. C min-1. Chromatographic and spectroscopic studies on the pyrolytic oil showed that the oil obtained from rapeseed could be use as a renewable fuels and chemical feedstock

190

Distribution of sulphur into products from waste tire pyrolysis  

International Nuclear Information System (INIS)

Tire pyrolysis is getting growing attention as an effective waste tire disposal method in comparison to environmentally less friendly methods like dumping or incineration. But the scrap tire sulphur content can be a potential obstacle to scrap tire utilization as a fuel. In this paper the distribution of sulphur into tire pyrolysis yields, solid (char) and liquid (tar), was investigated. The pyrolysis experiments were carried out under different conditions to determine the partitioning of sulphur into pyrolysis products. The influence of different temperatures and reaction times was investigated in a laboratory flow reactor under nitrogen atmosphere. Solid and liquid residues were collected and analyzed by elemental analysis. The sulphur content in residual char and tar was determined using an elemental analyzer and the sulphur forms in tar were characterized by the X-ray photoelectron spectroscopy (XPS). (Authors)

191

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 C. 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 C. The char properties were characterized and their potential applications are discussed.

Trinh, Ngoc Trung; Jensen, Peter Arendt

2013-01-01

192

Investigating the potential for a self-sustaining slow pyrolysis system under varying operating conditions.  

Science.gov (United States)

This work aimed to investigate the impact of highest treatment temperature (HTT), heating rate, carrier gas flow rate and feedstock on the composition and energy content of pyrolysis gas to assess whether a self-sustained system could be achieved through the combustion of the gas fraction alone, leaving other co-products available for alternative high-value uses. Calculations based on gas composition showed that the pyrolysis process could be sustained by the energy contained within the pyrolysis gases alone. The lower energy limit (6% biomass higher heating value (HHV)) was surpassed by pyrolysis at ?450C while only a HTT of 650C consistently met the upper energy limit (15% biomass HHV). These findings fill an important gap in literature related to the energy balance of the pyrolysis systems for biochar production, and show that, at least from an energy balance perspective; self-sustained slow pyrolysis for co-production of biochar and liquid products is feasible. PMID:24747394

Crombie, Kyle; Maek, Ond?ej

2014-06-01

193

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

194

A new pyrolysis technique using a diamond anvil cell: in situ visualization of kerogen transformation  

Energy Technology Data Exchange (ETDEWEB)

A pyrolysis technique has been developed to study hydrocarbon source rock potential by in situ visualization of kerogen transformation in a diamond anvil cell under a microscope (white and UV-light) using a CCD video monitoring system. The technique unables one to observe directly the processes and timing (or temperature) of kerogen transformation during pyrolysis in open or closed systems (either anhydrous or hydrous). It has been used to study a Green River kerogen and a lignite sample at heating rates similar to Rock-Eval pyrolysis under several pyrolysis conditions.

Huang, W.L. [Exxon Production Research Company, Houston, TX (United States)

1996-01-01

195

Pyrolysis of Precambrian kerogens: constraints and capabilities.  

Science.gov (United States)

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. PMID:7097782

Nagy, B

1982-01-01

196

Pyrolysis of Precambrian kerogens - Constraints and capabilities  

Science.gov (United States)

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

197

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

Science.gov (United States)

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

198

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

Science.gov (United States)

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

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

1994-06-14

199

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

200

Pyrolysis pretreatment of biomass for entrained-flow gasification  

International Nuclear Information System (INIS)

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

 
 
 
 
201

Pyrolysis of hardwoods residues: on kinetics and chars characterization  

Energy Technology Data Exchange (ETDEWEB)

Evolution of chemical and textural-morphological features characterizing two native Argentinian hardwood species (Aspidosperma Quebracho Blanco Schlecht and Aspidosperma Australe), subjected to pyrolysis at different operating conditions, is analysed by several techniques. Surface areas of raw materials and pyrolysed samples are evaluated from physical adsorption measurements employing N{sub 2} at 77 K and CO{sub 2} at 298 K. The samples are also examined by optical and scanning electronic microscopy. Results point to significant feature changes, which are, in general, strongly affected by pyrolysis conditions, particularly temperature. Furthermore, kinetic measurements of wood pyrolysis are performed by non-isothermal thermogravimetric analysis, from ambient temperature up to 1123 K. A deactivation model reported in the literature, which predicts an increase of activation energy with reaction extent, successfully describes kinetic data for both species over the whole range of degradation temperatures. (author)

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

1999-11-01

202

Thermal response of heat-resistant layer with pyrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available A model is developed for analyzing the thermal response of the heat-resistant layer composed of high silica fiber reinforced phenolic matrix composites(SiO2/P and aluminum, in which pyrolysis and phase transitions are exsited, such as melt, vaporization and sublimation. Based on this model, the thermal response of the heat-resistant layer with different SiO2/P thickness is calculated under a heat flux by using FORTRAN codes. As indicated in the results, the slope of temperature gets a sudden decline at the pyrolysis interface, which is due to the latent heat of pyrolysis; the thickness of heat-resistant layer has little influence on the heating-surface temperature, however, the back temperature may increase with the decreasing thickness; and the thermal conductivity of carbonized layer is very important to thermal response.

Huang Haiming

2012-01-01

203

The impact of ocean deoxygenation on iron release from continental margin sediments  

Science.gov (United States)

In the oceans' high-nitrate-low-chlorophyll regions, such as the Peru/Humboldt Current system and the adjacent eastern equatorial Pacific, primary productivity is limited by the micronutrient iron. Within the Peruvian upwelling area, bioavailable iron is released from the reducing continental margin sediments. The magnitude of this seafloor source could change with fluctuations in the extension or intensity of the oxygen minimum zones. Here we show that measurements of molybdenum, uranium and iron concentrations can be used as a proxy for sedimentary iron release, and use this proxy to assess iron release from the sea floor beneath the Peru upwelling system during the past 140,000 years. We observe a coupling between levels of denitrification, as indicated by nitrogen isotopes, trace metal proxies for oxygenation, and sedimentary iron concentrations. Specifically, periods with poor upper ocean oxygenation are characterized by more efficient iron retention in the sediment and a diminished iron supply to the water column. We attribute efficient iron retention under more reducing conditions to widespread sulphidic conditions in the surface sediment and concomitant precipitation of iron sulphides. We argue that iron release from continental margin sediments is most effective in a narrow redox window where neither oxygen nor sulphide is present. We therefore suggest that future deoxygenation in the Peru upwelling area would be unlikely to result in increased iron availability, whereas in weaker oxygen minimum zones partial deoxygenation may enhance the iron supply.

Scholz, Florian; McManus, James; Mix, Alan C.; Hensen, Christian; Schneider, Ralph R.

2014-06-01

204

Alkaline deoxygenated graphene oxide for supercapacitor applications: An effective green alternative for chemically reduced graphene  

Science.gov (United States)

Graphene is a promising electrode material for energy storage applications. The most successful method for preparing graphene from graphite involves the oxidation of graphite to graphene oxide (GO) and reduction back to graphene. Even though different chemical and thermal methods have been developed to reduce GO to graphene, the use of less toxic materials to generate graphene still remains a challenge. In this study we developed a facile one-pot synthesis of deoxygenated graphene (hGO) via alkaline hydrothermal process, which exhibits similar properties to the graphene obtained via hydrazine reduction (i.e. the same degree of deoxygenation found in hydrazine reduced GO). Moreover, the hGO formed freestanding, binder-free paper electrodes for supercapacitors. Coin cell type (CR2032) symmetric supercapacitors were assembled using the hGO electrodes. Electrochemical characterization of hGO was carried out using lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) and ethylmethylimidazolium bis-(trifluoromethanesulfonyl)imide (EMITFSI) electrolytes. The results for the hGO electrodes were compared with the hydrazine reduced GO (rGO) electrode. The hGO electrode exhibits a energy density of 20Whkg-1 and 50Whkg-1 in LiTFSI and EMITFSI respectively, while delivering a maximum power density of 11kWkg-1 and 14.7kWkg-1 in LiTFSI and EMITFSI, respectively.

Perera, Sanjaya D.; Mariano, Ruperto G.; Nijem, Nour; Chabal, Yves; Ferraris, John P.; Balkus, Kenneth J.

2012-10-01

205

Dimethylarsine: Pyrolysis mechanisms and use for OMVPE growth  

Science.gov (United States)

The pyrolysis mechanisms of dimethylarsine (DMAsH) have been studied mass spectrometrically in an atmospheric pressure flow tube reactor. In either the D2 or He ambient, DMAsH will be converted to trimethylarsine (TMAs) at temperatures of 400 500 via a homogeneous CH3 radical chain reaction. Supplemental CH3 radicals, produced from azomethane ((CH3)2N2) pyrolysis, have resulted in a significant increase in the pyrolysis rate for DMAsH. As temperature is increased beyond 500, the product TMAs will decompose due to hydrogenolysis in D2 and homolysis in He. At a GaAs surface, DMAsH pyrolyzes heterogeneously. The pyrolysis rate is further accelerated by the addition of trimethylgallium (TMGa). DMAsH has also been combined with TMGa to grow GaAs layers. The as-grown epilayers, at 1 atm and substrate temperatures of 570 720, are all p-type with the net hole concentration dependent on the carrier gas. The use of N2 leads to a higher concentration as compared to that in H2. Photoluminescence spectra have indicated the acceptor to be carbon. A mechanism is developed to interpret these results based on the pyrolysis reactions determined from the kinetic studies.

Li, S. H.; Larsen, C. A.; Chen, C. H.; Stringfellow, G. B.; Brown, D. W.

1990-04-01

206

Heterogeneity in cellulose pyrolysis indicated from the pyrolysis in sulfolane  

Energy Technology Data Exchange (ETDEWEB)

In sulfolane (tetramethylene sulfone), which is a good solvent for the primary product, levoglucosan, cellulose is pyrolyzed completely into soluble products without forming any char. Residues during pyrolysis in sulfolane at 200, 240 and 330{sup o}C were obtained always as colorless non-carbonized substances. From the change in the crystallinity and crystallite size as compared with the ordinary pyrolysis, a heterogeneous mechanism is indicated for cellulose pyrolysis, starting from a molecule which is less stabilized due to lack of some intermolecular interactions. (author)

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

2006-06-01

207

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 high catalyst/tyre ratio favored to increase the concentration of light naphtha (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

2006-09-21

208

Thermal Pyrolysis of Polyethylene: Kinetic Study  

Directory of Open Access Journals (Sweden)

Full Text Available

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

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

Elham Khaghanikavkani

2011-09-01

209

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

210

Methane Pyrolysis and Disposing Off Resulting Carbon  

Science.gov (United States)

Sabatier/Electrolysis (S/E) is a leading process for producing methane and oxygen for application to Mars ISPP. One significant problem with this process is that it produces an excess of methane for combustion with the amount of oxygen that is produced. Therefore, one must discard roughly half of the methane to obtain the proper stoichiometric methane/oxygen mixture for ascent from Mars. This is wasteful of hydrogen, which must be brought from Earth and is difficult to transport to Mars and store on Mars. To reduced the problem of transporting hydrogen to Mars, the S/E process can be augmented by another process which reduces overall hydrogen requirement. Three conceptual approaches for doing this are (1) recover hydrogen from the excess methane produced by the S/E process, (2) convert the methane to a higher hydrocarbon or other organic with a lower H/C ratio than methane, and (3) use a separate process (such as zirconia or reverse water gas shift reaction) to produce additional oxygen, thus utilizing all the methane produced by the Sabatier process. We report our results here on recovering hydrogen from the excess methane using pyrolysis of methane. Pyrolysis has the advantage that it produces almost pure hydrogen, and any unreacted methane can pass through the S/E process reactor. It has the disadvantage that disposing of the carbon produced by pyrolysis presents difficulties. Hydrogen may be obtained from methane by pyrolysis in the temperature range 10000-12000C. The main reaction products are hydrogen and carbon, though very small amounts of higher hydrocarbons, including aromatic hydrocarbons are formed. The conversion efficiency is about 95% at 12000C. One needs to distinguish between thermodynamic equilibrium conversion and conversion limited by kinetics in a finite reactor.

Sharma, P. K.; Rapp, D.; Rahotgi, N. K.

1999-01-01

211

Enhancing biochar yield by co-pyrolysis of bio-oil with biomass: Impacts of potassium hydroxide addition and air pretreatment prior to co-pyrolysis.  

Science.gov (United States)

The influence of KOH addition and air pretreatment on co-pyrolysis (600C) of a mixture of bio-oil and biomass (aspen wood) was investigated with the goal of increasing biochar yield. The bio-oil was produced as a byproduct of the pyrolysis of biomass and recycled in subsequent runs. Co-pyrolysis of the biomass with the recycled bio-oil resulted in a 16% mass increase in produced biochar. The yields were further increased by either air pretreatment or KOH addition prior to co-pyrolysis. Air pretreatment at 220C for 3h resulted in the highest mass increase (32%) compared to the base case of pyrolysis of biomass only. No synergistic benefit was observed by combining KOH addition with air pretreatment. In fact, KOH catalyzed reactions that increased the bed temperature resulting in carbon loss via formation of CO and CO2. PMID:25189513

Veksha, Andrei; Zaman, Waheed; Layzell, David B; Hill, Josephine M

2014-11-01

212

Slow Pyrolysis of Cassava Wastes for Biochar Production and Characterization  

Directory of Open Access Journals (Sweden)

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

Nurhidayah Mohamed Noor

2012-01-01

213

TG-FTIR study on urea-formaldehyde resin residue during pyrolysis and combustion.  

Science.gov (United States)

The pyrolysis and combustion characteristics of urea-formaldehyde resin (UFR) residue were investigated by using thermogravimetric analysis, coupled with Fourier transform infrared spectroscopy (TG-FTIR). It is indicated that the pyrolysis process can be subdivided into three stages: drying the sample, fast thermal decomposition and further cracking process. The total weight loss of 90 wt.% at 950 degrees C is found in pyrolysis, while 74 wt.% of the original mass lost in the second stage is between 195 degrees C and 430 degrees C. The emissions of carbon dioxide, isocyanic acid, ammonia, hydrocyanic acid and carbon monoxide are identified in UFR residue pyrolysis, moreover, isocyanic acid emitted at low temperature is found as the most important nitrogen-containing gaseous product in UFR residue pyrolysis, and there is a large amount of hydrocyanic acid emitted at high temperature. The similar TG and emission characteristics as the first two stages during pyrolysis are found in UFR residue combustion at low temperature. The combustion process almost finishes at 600 degrees C; moreover, carbon dioxide and water are identified as the main gaseous products at high temperature. It is indicated that the UFR residue should be pyrolyzed at low temperature to remove the initial nitrogen, and the gaseous products during pyrolysis should be burnt in high temperature furnace under oxygen-rich conditions for pollutant controlling. PMID:19735979

Jiang, Xuguang; Li, Chunyu; Chi, Yong; Yan, Jianhua

2010-01-15

214

Fast pyrolysis of linseed. Product yields and compositions  

Energy Technology Data Exchange (ETDEWEB)

Fixed-bed fast pyrolysis experiments have been conducted on a sample of linseed (Linum usitatissimum L.) to determine particularly the effect of pyrolysis temperature, heating rate, particle size and sweep gas flow rate on the pyrolysis product yields and their compositions. The maximum oil yield of 57.7wt.% was obtained at a final pyrolysis temperature of 550C, particle size range 0.6mmpyrolysis products were characterised by elemental analysis and various chromatographic and spectroscopic techniques. Chromatographic and spectroscopic studies on oil showed that it can be used as a renewable fuel and chemical feedstock, with a calorific value of 38.45MJ/kg and empirical formula of CH{sub 1.64}O{sub 0.11}N{sub 0.03}.

Acikgoz, C.; Onay, O.; Kockar, O.M. [Department of Chemical Engineering, Faculty of Engineering and Architecture, Iki Eylul Campus, Anadolu University, Eskisehir 26470 (Turkey)

2004-06-01

215

Impact of thermal pretreatment on the fast pyrolysis conversion of Southern Pine  

Energy Technology Data Exchange (ETDEWEB)

Background: Thermal pretreatment of biomass ranges from simple (nondestructive) drying to more severe treatments that cause devolatization, depolymerization and carbonization. These pretreatments have demonstrated promise for transforming raw biomass into feedstock material that has improved milling, handling, storage and conversion properties. In this work, southern pine material was pretreated at 120, 180, 230 and 270 degrees C, and then subjected to pyrolysis tests in a continuous-feed bubbling-fluid bed pyrolysis system. Results: High pretreatment temperatures were associated with lower specific grinding energies, higher grinding rates and lower hydrogen and oxygen contents. Higher pretreatment temperatures were also correlated with increased char production, decreased total acid number and slight decrease in the oxygen content of the pyrolysis liquid fraction. Conclusion: Thermal pretreatment has both beneficial and detrimental impacts on fast pyrolysis conversion of pine material to bio-oil, and the effect of thermal pretreatment on upgrading of pyrolysis bio-oil requires further attention.

Tyler L. Westover; Manunya Phanphanich; Micael L. Clark; Sharna R. Rowe; Steven E. Egan; Christopher T Wright; Richard D. Boardman; Alan H. Zacher

2013-01-01

216

Comparison of oscillations of skin blood flow and deoxygenation in vastus lateralis in light exercise.  

Science.gov (United States)

The purpose of the present study was to compare oscillation of skin blood flow with that of deoxygenation in muscle during light exercise in order to determine the physiological significance of oscillations in deoxygenation. Prolonged exercise with 50% of peak oxygen uptake was performed for 60 min. Skin blood flow (SBF) was measured using a laser blood flow meter on the right vastus lateralis muscle. Deoxygenated haemoglobin/myoglobin (DHb/Mb) concentration in the left vastus lateralis were measured using a near-infrared spectroscopy system. SBF and DHb/Mb during exercise were analysed by fast Fourier transform. We classified frequency bands according to previous studies (Kvernmo et al. 1999, Kvandal et al. 2006) into phase I (0.005-0.0095 and 0.0095-0.02 Hz), phase II (0.02-0.06 Hz: phase II) and phase III (0.06-0.16 Hz). The first peak of power spectra density (PSD) in SBF appeared at 0.0078 Hz in phase I. The second peak of PSD in SBF appeared at 0.035 Hz. The third peak of PSD in SBF appeared at 0.078 Hz. The first peak of PSD in DHb/Mb appeared at 0.0039 Hz, which was out of phase I. The second peak of PSD in DHb/Mb appeared at 0.016 Hz. The third peak of PSD in DHb/Mb appeared at 0.035 Hz. The coefficient of cross correlation was very low. Cross power spectra density showed peaks of 0.0039, 0.016 and 0.035 Hz. It is concluded that a peak of 0.016 Hz in oscillations of DHb/Mb observed in muscle during exercise is associated with endothelium-dependent vasodilation (phase I) and that a peak of 0.035 Hz in DHb/Mb is associated with sympathetic nerve activity (phase II). It is also confirmed that each peak of SBF oscillations is observed in each phase. PMID:25187674

Yano, T; Lian, C-S; Afroundeh, R; Shirakawa, K; Yunoki, T

2014-03-01

217

Pyrolysis of Municipal Solid Waste.  

Science.gov (United States)

The pyrolysis of municipal solid waste (MSW) is a potential method of producing useful fuels. However, past attempts to utilize the technology have resulted in facilities that have not performed as expected, producing low yields of inferior products. Back...

J. E. Helt, R. K. Agrawal, N. Mallya

1987-01-01

218

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

2013-10-28

219

Gas phase temperature measurements in the liquid and particle regime of a flame spray pyrolysis process using O2-based pure rotational coherent anti-Stokes Raman scattering.  

Science.gov (United States)

For the production of oxide nanoparticles at a commercial scale, flame spray processes are frequently used where mostly oxygen is fed to the flame if high combustion temperatures and thus small primary particle sizes are desired. To improve the understanding of these complex processes in situ, noninvasive optical measurement techniques were applied to characterize the extremely turbulent and unsteady combustion field at those positions where the particles are formed from precursor containing organic solvent droplets. This particle-forming regime was identified by laser-induced breakdown detection. The gas phase temperatures in the surrounding of droplets and particles were measured with O(2)-based pure rotational coherent anti-Stokes Raman scattering (CARS). Pure rotational CARS measurements benefit from a polarization filtering technique that is essential in particle and droplet environments for acquiring CARS spectra suitable for temperature fitting. Due to different signal disturbing processes only the minority of the collected signals could be used for temperature evaluation. The selection of these suitable signals is one of the major problems to be solved for a reliable evaluation process. Applying these filtering and signal selection steps temperature measurements have successfully been conducted. Time-resolved, single-pulse measurements exhibit temperatures between near-room and combustion temperatures due to the strongly fluctuating and flickering behavior of the particle-generating flame. The mean flame temperatures determined from the single-pulse data are decreasing with increasing particle concentrations. They indicate the dissipation of large amounts of energy from the surrounding gas phase in the presence of particles. PMID:22945152

Engel, Sascha R; Koegler, Andreas F; Gao, Yi; Kilian, Daniel; Voigt, Michael; Seeger, Thomas; Peukert, Wolfgang; Leipertz, Alfred

2012-09-01

220

Pyrolysis and volatilization of cocaine  

International Nuclear Information System (INIS)

The increasing popularity of inhaling cocaine vapor prompted the present study, to determine cocaine's fate during this process. The free base of [3H]cocaine (1 microCi/50 mg) was added to a glass pipe, which was then heated in a furnace to simulate freebasing. Negative pressure was used to draw the vapor through a series of glass wool, ethanol, acidic, and basic traps. Air flow rate and temperature were found to have profound effects on the volatilization and pyrolysis of cocaine. At a temperature of 260 degrees C and a flow rate of 400 mL/min, 37% of the radioactivity remained in the pipe, 39% was found in the glass wool trap, and less than 1% in the remainder of the volatilization apparatus after a 10-min volatilization. Reducing the air flow rate to 100 mL/min reduced the amount of radioactivity collected in the glass wool trap to less than 10% of the starting material and increased the amount that remained in the pipe to 58%. GC/MS analysis of the contents of the glass wool trap after volatilization at 260 degrees C and a flow rate of 400 mL/min revealed that 60% of the cocaine remained intact, while approximately 6 and 2% of the starting material was recovered as benzoic acid and methylecgonidine, respectively. As the temperature was increased to 650 degrees C, benzoic acid and methylecgonidine accounted for 83 and 89% of the starting material, respectively, whereas only 2% of the cocaine remained intact. Quantitation of cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

 
 
 
 
221

Secondary cracking of C4 hydrocarbons from heavy oil catalytic pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

This study was conducted in response to the recent interest in the conversion of C4 hydrocarbons into ethene and propene. C4 hydrocarbons are significant intermediate products for catalytic pyrolysis of heavy oils. The produced C4 hydrocarbons can undergo secondary cracking reactions, yielding ethene, propene and other products. In order to better understand the reaction mechanism of heavy oil catalytic pyrolysis, this study examined the secondary cracking performance of C4 hydrocarbons from heavy oil catalytic pyrolysis, with particular focus on the influence of reaction temperature on feed conversion, product yields and liquid components. A confined fluidized bed reactor was used to examine the cracking behaviours on catalyst CEP-1 and quartz sand for C4 hydrocarbons from heavy oil catalytic pyrolysis. C4 hydrocarbons showed a good cracking ability on CEP-1. Butene was easier to convert than butane. Butane demonstrated a good cracking ability at high reaction temperatures only. On catalyst CEP-1, C4 hydrocarbons underwent cracking reactions, as well as reactions such as hydrogen transfer, polymerization and aromatization. The high conversion of C4 hydrocarbons thermal pyrolysis suggests that free radical reactions play an important role in the secondary cracking of C4 hydrocarbons. The product yields of C4 hydrocarbons pyrolysis on quartz sand were found to be lower than those on catalyst CEP-1. The selectivity of propene is higher than that of ethene for both catalytic pyrolysis and thermal pyrolysis of C4 hydrocarbons. 9 refs., 6 tabs., 6 figs.

Meng, X.; Xu, C.; Gao, J. [China Univ. of Petroleum, Changping, Beijing (China). State Key Laboratory of Heavy Oil Processing

2006-06-15

222

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

Science.gov (United States)

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N2 adsorption-desorption isotherms, and NH3 temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H2O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro-d-galactitol and 1,5-anhydro-d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H2O content in bio-oil was decreased dramatically (8.93wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis. PMID:25136282

2014-01-01

223

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

Science.gov (United States)

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

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

2014-08-01

224

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

Science.gov (United States)

The catalytic co-pyrolysis of a seaweed biomass, Laminaria japonica, and a typical polymer material, polypropylene, was studied for the first time. A mesoporous material Al-SBA-15 was used as a catalyst. Pyrolysis experiments were conducted using a fixed-bed reactor and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS). BET surface area, N2 adsorption-desorption isotherms, and NH3 temperature programmed desorption were measured to examine the catalyst characteristics. When only L. japonica was pyrolyzed, catalytic reforming slightly increased the gas yield and decreased the oil yield. The H2O content in bio-oil was increased by catalytic reforming from 42.03 to 50.32wt% due to the dehydration reaction occurring on the acid sites inside the large pores of Al-SBA-15. Acids, oxygenates, mono-aromatics, poly aromatic hydrocarbons, and phenolics were the main components of the bio-oil obtained from the pyrolysis of L. japonica. Upon catalytic reforming over Al-SBA-15, the main oxygenate species 1,4-anhydro-d-galactitol and 1,5-anhydro-d-manitol were completely removed. When L. japonica was co-pyrolyzed with polypropylene, the H2O content in bio-oil was decreased dramatically (8.93wt% in the case of catalytic co-pyrolysis), contributing to the improvement of the oil quality. A huge increase in the content of gasoline-range and diesel-range hydrocarbons in bio-oil was the most remarkable change that resulted from the co-pyrolysis with polypropylene, suggesting its potential as a transport fuel. The content of mono-aromatics with high economic value was also increased significantly by catalytic co-pyrolysis. PMID:25136282

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

2014-01-01

225

Gas sensing properties of undoped and antimony doped tin oxide films prepared by spray pyrolysis and electron beam evaporation method  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The thin films of undoped and antimony doped tin oxide films were prepared oil glass substrates by spray pyrolysis and electron beam evaporation techniques. The Substrate temperature was varied between 300 and 370 degrees C in case of spray pyrolysis and 200 degrees C in case of electron beam evaporation. The films were tested as gas sensors in the presence of liquid petroleum gas (LPG) and compressed natural gas (CNG). Undoped and antimony doped tin oxide films prepared by spray pyrolysis we...

Shamala, Ks; Murthy, Lcs; Rao, Narasimha K.

2006-01-01

226

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 850C. 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

2009-02-01

227

Co-pyrolysis of lignite and sugar beet pulp  

International Nuclear Information System (INIS)

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

228

Growth of polycrystalline SnS films by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-07-18

229

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.For the PAN-DMF system measurements at different samples heating rates were performed. The obtained results were in accordance with the kinetics of heterogeneous processes theory. The process rates in stages increased along with the temperature increase, and TG, DTG and HF function curves were shifted into higher temperature range. This means that the process of pyrolysis and oxidation of PAN in dry air can be carried out in a controlled way.http://dx.doi.org/10.5755/j01.ms.17.1.246

Anna BIEDUNKIEWICZ

2011-03-01

230

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...

231

Spray pyrolysis technique for the deposition of superconducting films  

International Nuclear Information System (INIS)

Research has been performed on the use of chemical spray pyrolysis for depositing films of YBCO. The effects of reagent concentration, deposition rate, substrate temperature and substrate type were investigated. Films from less than 2 to more than 10 microns thick were deposited on single crystal strontium titanate, polycrystalline alumina and type 304 stainless steel

232

Vacuum Pyrolysis and Related ISRU Techniques  

Science.gov (United States)

A number of ISRU-related techniques have been developed at NASA Goddard Space Flight Center. The focus of the team has been on development of the vacuum pyrolysis technique for the production of oxygen from the lunar regolith. However, a number of related techniques have also been developed, including solar concentration, solar heating of regolith, resistive heating of regolith, sintering, regolith boiling, and instrumentation development. An initial prototype system was developed to vaporize regolith simulants using a ~1m2 Fresnel lens. This system was successfully used to vaporize quantities of ~1g, and both mass spectroscopy of the gasses produced and Scanning Electron Microscopy (SEM) of the slag were done to show that oxygen was produced. Subsequent tests have demonstrated the use of a larger system with a 3.8m diameter reflective mirror to vaporize the regolith. These results and modeling of the vacuum pyrolysis reaction have indicated that the vaporization of the oxides in the regolith will occur at lower temperature for stronger vacuums. The chemical modeling was validated by testing of a resistive heating system that vaporized quantities of ~10g of MLS-1A. This system was also used to demonstrate the sintering of regolith simulants at reduced temperatures in high vacuum. This reduction in the required temperature prompted the development of a small-scale resistive heating system for application as a scientific instrument as well as a proof-of principle experiment for oxygen production.

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

2007-01-01

233

Vacuum Pyrolysis and Related ISRU Techniques  

Science.gov (United States)

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

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

2007-01-01

234

Experimental investigation of flash pyrolysis oil droplet combustion  

DEFF Research Database (Denmark)

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

Jensen, Peter A.; Dam-Johansen, Kim

2013-01-01

235

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

236

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

237

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

238

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

239

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

Directory of Open Access Journals (Sweden)

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

Jorge Daniel Prez

2011-11-01

240

Microwave pyrolysis for conversion of materials to energy : A review  

International Nuclear Information System (INIS)

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

 
 
 
 
241

Development of advanced technologies for biomass pyrolysis  

Science.gov (United States)

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

Xu, Ran

242

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

International Nuclear Information System (INIS)

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

243

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

244

Co-pyrolysis of coal with organic solids  

Energy Technology Data Exchange (ETDEWEB)

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

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

1995-12-01

245

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

246

Modeling and experimental verification of physical and chemical processes during pyrolysis of a refuse-derived fuel  

Energy Technology Data Exchange (ETDEWEB)

A model for refuse-derived fuel (RDF) conventional pyrolysis in a fixed-bed reactor is presented. The model investigates the influence of the heat- and mass-transfer processes on the pyrolysis product yields. Solid degradation reactions have been modeled by assuming that the interactions between the main RDF components during pyrolysis are negligible and that the RDF pyrolysis behavior may be considered as the sum of the separate behaviors of primary reacting species. The model accounts for conductive and convective heat transfer within the solid matrix and secondary tar-cracking reactions, as well as for variability in physical properties and in the void fraction of the pyrolyzing material. Quite good agreement was found between model results and experimental data obtained for conventional pyrolysis of a RDF in a laboratory-scale fixed-bed reactor. The model is able to predict the temperature transients, the rate of gas generation, and the product final yields during conventional pyrolysis of RDF.

Cozzani, V.; Tognotti, L. [Univ. degli Studi di Pisa (Italy); Nicolella, C.; Rovatti, M. [Univ. degli Studi di Genova (Italy). Ist. di Scienze e Tecnologie dell`Ingegneria Chimica

1996-01-01

247

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

248

Pyrolysis oil from carbonaceous solid wastes in Malaysia  

International Nuclear Information System (INIS)

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

249

Pyrolysis of heavy crude fractions  

Energy Technology Data Exchange (ETDEWEB)

Given the continuing growth of ethylene production and the shrinking supply of straight-run gasoline fractions for this purpose, it is of interest to consider the utilization for this purpose of the heavier petroleum fractions such as gas condensates and atmospheric gas oil, which complicates pyrolysis technology. In this connection, research to streamline pyrolysis technology in this direction at the All-Union Scientific Research Institute of Organic Synthesis is described here. Experiments with gasoline fractions of gaseous condensate from the Orenburg Deposit and fractions of atmospheric gas oil from the Romashkino Deposit were conducted in a pilot pyrolysis facility handling up to 300 cc/hr. The resulting yields indicate that specimens subjected to selective hydrodearomatization result in a less than or equal to 75% yield of gaseous products compared with 69% for other specimens, as well as in a 10 rel. % higher relative yield of ethylene and an increase from 20 to 21 to 26 to 28 mass % in the benzene concentration of the liquid pyrolysis products. These and other findings point to the expendiency of using gas-condensate gasoline as a raw material for pyrolysis. Similarly, hydrodearomatization of atmospheric gas oil facilitates its pyrolysis, especially in the presence of ethane, as also confirmed by industrial-scale operating trials. Thus, hydrodearomatization, which includes not only desulfurization but also the conversion of aromatic hydrocarbons to their naphthenic counterparts, is a promising new method of intensifying ethylene production and eliminating the difficulties associated with the use of heavier petroleum fractions. Then also coke-formation is sharply reduced. While for gas-condensate gasolines the attendant cost-effectiveness is yet to be determined, for atmospheric gas oil this method is clearly cost-effective. 5 references, 1 figure.

Chernyk, S.P.; Mukhina, T.N.; Furer, S.M.; Lesokhina, G.F.; Barabanov, N.L.

1979-01-01

250

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

Energy Technology Data Exchange (ETDEWEB)

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

Arceo, Elena; Ellman, Jonathan; Bergman, Robert

2010-05-03

251

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

Directory of Open Access Journals (Sweden)

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

Mario A. Snchez-Garca

2012-10-01

252

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

Energy Technology Data Exchange (ETDEWEB)

A concept for an advanced coal-fired combined-cycle power generating system is currently being developed. The first phase of this three-phase program consists of conducting the necessary research and development to define the system, evaluate the economic and technical feasibility of the concept, and prepare an R D plan to develop the concept further. Foster Wheeler Development Corporation is leading a team ofcompanies involved in this effort. The system proposed to meet these goals is a combined-cycle system where air for a gas turbine is indirectly heated to approximately 1800[degrees]F in furnaces fired with cool-derived fuels and then directly heated in a natural-gas-fired combustor up to about 2400[degrees]F. The system is based on a pyrolyzing process that converts the coal into a low-Btu fuel gas and char. The fuelgas is a relatively clean fuel, and it is fired to heat tube surfaces that are susceptible to corrosion and problems from ash deposition. In particular, the high-temperature air heater tubes, which will need tobe a ceramic material, will be located in a separate furnace or region of a furnace that is exposed to combustion products from the low-Btu fuel gas only. A simplified process flow diagram is shown.

1992-11-01

253

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

254

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

255

Bio-oil from flash pyrolysis of agricultural residues  

Energy Technology Data Exchange (ETDEWEB)

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

Ibrahim, N.B.

2012-08-15

256

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

Science.gov (United States)

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

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

2012-05-01

257

Co-pyrolysis of low rank coals and biomass: Product distributions  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis and gasification of combined low rank coal and biomass feeds are the subject of much study in an effort to mitigate the production of green house gases from integrated gasification combined cycle (IGCC) systems. While co-feeding has the potential to reduce the net carbon footprint of commercial gasification operations, the effects of co-feeding on kinetics and product distributions requires study to ensure the success of this strategy. Southern yellow pine was pyrolyzed in a semi-batch type drop tube reactor with either Powder River Basin sub-bituminous coal or Mississippi lignite at several temperatures and feed ratios. Product gas composition of expected primary constituents (CO, CO{sub 2}, CH{sub 4}, H{sub 2}, H{sub 2}O, and C{sub 2}H{sub 4}) was determined by in-situ mass spectrometry while minor gaseous constituents were determined using a GC-MS. Product distributions are fit to linear functions of temperature, and quadratic functions of biomass fraction, for use in computational co-pyrolysis simulations. The results are shown to yield significant nonlinearities, particularly at higher temperatures and for lower ranked coals. The co-pyrolysis product distributions evolve more tar, and less char, CH{sub 4}, and C{sub 2}H{sub 4}, than an additive pyrolysis process would suggest. For lignite co-pyrolysis, CO and H{sub 2} production are also reduced. The data suggests that evolution of hydrogen from rapid pyrolysis of biomass prevents the crosslinking of fragmented aromatic structures during coal pyrolysis to produce tar, rather than secondary char and light gases. Finally, it is shown that, for the two coal types tested, co-pyrolysis synergies are more significant as coal rank decreases, likely because the initial structure in these coals contains larger pores and smaller clusters of aromatic structures which are more readily retained as tar in rapid co-pyrolysis.

Soncini, Ryan M; Means, Nicholas C; Weiland, Nathan T

2013-10-01

258

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

Directory of Open Access Journals (Sweden)

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

Bei Liu

2013-02-01

259

Experiments and stochastic simulations of lignite coal during pyrolysis and gasification  

International Nuclear Information System (INIS)

Highlights: ? Lignite pyrolysis and gasification has been conducted in a semi batch reactor. ? The objective is to understand mechanism of syngas evolution during pyrolysis. ? Stochastic simulations of lignite pyrolysis were conducted using Gillespie algorithm. ? First order, single step mechanism failed to fit cumulative yield of hydrogen. ? Evolution of hydrogen via pyrolysis of gaseous hydrocarbon following bridges scission. -- Abstract: Lignite pyrolysis and gasification has been conducted in a semi batch reactor at reactor temperatures of 800950 C in 50 C intervals. CO2 has been used as the gasifying agent for gasification experiments. The objective of this investigation is to understand the mechanism of syngas evolution during pyrolysis and to unravel the effect of CO2 on pyrolysis mechanism. Stochastic simulations of lignite pyrolysis have been conducted using Gillespie algorithm. Two reaction mechanisms have been used in the simulations; first order, single step mechanism and the FLASHCHAIN mechanism. The first order single step mechanism was successful in fitting cumulative yield of CO2, CO, CH4 and other hydrocarbons (CnHm). The first order, single step failed to fit the cumulative yield of hydrogen, which suggests a more complex mechanism for hydrogen evolution. Evolution of CO2, CO, CH4, CnHm and H2 flow rates has been monitored. The only effect of CO2 on pyrolysis mechanism is promotion of reverse water gas shift reaction for the experiments described here. Methane evolution extended for slightly longer time than other hydrocarbons and hydrogen evolution extended for a slightly longer time than methane. This indicated the evolution of hydrogen via further pyrolysis of aliphatic hydrocarbon. It is also suggested that this step occurs in series after aliphatic hydrocarbons evolution by bridges scission.

260

Modeling, simulation and estimation of optimum parameters in pyrolysis of biomass  

International Nuclear Information System (INIS)

Pyrolysis is a process by which a biomass feedstock is thermally degraded in the absence of air/oxygen. It is used for the production of solid (charcoal), liquid (tar and other organics) and gaseous products. The present work involves the estimation of optimum parameters in the pyrolysis of biomass for both non-isothermal and isothermal conditions. The modeling equations are solved numerically using the fourth order Runge-Kutta method over a wide range of heating rates (25-360 K/s) and temperatures (773-1773 K). The simulated results are compared with those reported in the literature and found to be in good agreement qualitatively in the range of operating conditions covered, but some very interesting trends are found, especially with respect to the effect of net heating rate and temperature on final pyrolysis time. The final pyrolysis time first decreases at lower values of net heating rate or temperature and then increases as net heating rate or temperature is further increased, providing an optimum value of net heating rate or temperature at which final pyrolysis time is minimum. This interesting phenomenon, which was not reported by investigators earlier, is well explained by means of the pyrolysis kinetics

 
 
 
 
261

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

DEFF Research Database (Denmark)

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

Madsen, Anders Theilgaard; Rozmys?owicz, Bartosz

2013-01-01

262

The structure of a deoxygenated 400 kDa haemoglobin reveals ternary- and quaternary-structural changes of giant haemoglobins.  

Science.gov (United States)

The quaternary structures of invertebrate haemoglobins (Hbs) are quite different from those of vertebrate Hbs. The extracellular giant Hbs of molecular masses of about 400 and 3600?kDa are composed of a dome-shaped dodecameric subassembly which consists of four individual globin subunits. Several crystal structures of 400?kDa Hbs from annelids have been reported, including structures in oxygenated and partially unliganded states, but the structure of the fully deoxygenated state has not been reported. In the present study, crystal structures of V2Hb from the tube worm Lamellibrachia satsuma have been determined in both the fully oxygenated and deoxygenated states. A glycosylation site and novel metal-binding sites for divalent cations were clearly observed with no intersubunit interactions in V2Hb. A comparison of the oxygenated and the deoxygenated forms of V2Hb reveals that the ternary- and quaternary-structural changes occur in a manner that maintains the molecular D3 symmetry. These structures suggest that the mechanisms of quaternary-structural changes between the oxy and deoxy states for the giant Hbs are identical across species. PMID:25004960

Numoto, Nobutaka; Nakagawa, Taro; Ohara, Ryota; Hasegawa, Tomoyo; Kita, Akiko; Yoshida, Takao; Maruyama, Tadashi; Imai, Kiyohiro; Fukumori, Yoshihiro; Miki, Kunio

2014-07-01

263

Methods and apparatuses for preparing upgraded pyrolysis oil  

Energy Technology Data Exchange (ETDEWEB)

Methods and apparatuses for preparing upgraded pyrolysis oil are provided herein. In an embodiment, a method of preparing upgraded pyrolysis oil includes providing a biomass-derived pyrolysis oil stream having an original oxygen content. The biomass-derived pyrolysis oil stream is hydrodeoxygenated under catalysis in the presence of hydrogen to form a hydrodeoxygenated pyrolysis oil stream comprising a cyclic paraffin component. At least a portion of the hydrodeoxygenated pyrolysis oil stream is dehydrogenated under catalysis to form the upgraded pyrolysis oil.

Brandvold, Timothy A; Baird, Lance Awender; Frey, Stanley Joseph

2013-10-01

264

Acute exercise increases oxygenated and deoxygenated hemoglobin in the prefrontal cortex.  

Science.gov (United States)

Both acute and chronic exercise is consistently associated with a number of benefits to physical and mental health, including cardiovascular function, body weight, mood, and cognition. Near-infrared spectroscopy is an ideal method to measure changes in oxygenated and deoxygenated hemoglobin (O2Hb and dHb) levels in the prefrontal cortex (PFC) during exercise, to better understand the locus of such changes in affective and cognitive processes. The present study tracked time-dependent changes in O2Hb and dHb levels in the PFC as a function of parametrically manipulated target exercise intensity. Near-infrared spectroscopy was conducted as regular exercisers completed a 30-min bout of exercise with one of three target intensities: 52% (low condition), 68% (moderate condition), or 84% (high condition) of age-adjusted maximum heart rate. Heart rate data confirmed that the participants reached their goal intensities immediately, after 10?min, or after 20?min, respectively. Data showed that O2Hb and dHb levels in the PFC increased as a function of both exercise load and duration. An 84%>68%>52% difference was evident after 18?min of cycling for O2Hb and after 23?min of cycling for dHb. The present results add to the growing body of literature showing that at submaximal levels, increasing exercise intensities reliably promote prefrontal cerebral oxygenation. PMID:25275640

Giles, Grace E; Bruny, Tad T; Eddy, Marianna D; Mahoney, Caroline R; Gagnon, Stephanie A; Taylor, Holly A; Kanarek, Robin B

2014-11-12

265

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

266

Studies on steam pyrolysis of amides as a waste solvent management method  

International Nuclear Information System (INIS)

A laboratory scale pyrolysis reactor set-up was designed and constructed. The steam pyrolysis of dimethyl formamide (DMF) was studied in a tubular flow reactor at atmospheric pressure. The experimental data were obtained at a temperature range of 500-1100 deg C for different flow rates and steam to amide mass ratio. The reaction products were analyzed by gas chromatography and high pressure liquid chromatography. The experimental data was analyzed using a power law model to estimate apparent rate constant and corresponding activation energy. A reaction network model is being developed to include reaction mechanism of steam pyrolysis. (author)

267

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

268

?????????????????????? Experiment for Heating Rate on Pyrolysis Characteristics of Biomass-coal Mixture  

Directory of Open Access Journals (Sweden)

Full Text Available ?????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????The pyrolysis experiment on biomass, coal and biomass-coal mixture with various heating rates were carried out and analyzed by thermo-gravimetric analysis method. The effects of heating rates on the process of pyrolysis characteristics of biomass, coal and biomass-coal mixture were obtained and analyzed. The experiment results showed that the thermo-gravimetric curves move to the high-side of temperature while heating rate increases, there is a large different characteristic between biomass and coal, and the pyrolysis characteristic of biomass-coal mixture occur separately the characteristics of biomass or coal at different stages.

??

2011-03-01

269

Phosphorus catalysis in the pyrolysis behaviour of biomass  

Energy Technology Data Exchange (ETDEWEB)

Phosphorus is a key plant nutrient and as such, is incorporated into growing biomass in small amounts. This paper examines the influence of phosphorus, present in either acid (H{sub 3}PO{sub 4}) or salt ((NH{sub 4}){sub 3}PO{sub 4}) form, on the pyrolysis behaviour of both Miscanthus x giganteus, and its cell wall components, cellulose, hemicellulose (xylan) and lignin (Organosolv). Pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) is used to examine the pyrolysis products during thermal degradation, and thermogravimetric analysis (TGA) is used to examine the distribution of char and volatiles. Phosphorus salts are seen to catalyse the pyrolysis and modify the yields of products, resulting in a large increase in char yield for all samples, but particularly for cellulose and Miscanthus. The thermal degradation processes of cellulose, xylan and Miscanthus samples occur in one step and the main pyrolysis step is shifted to lower temperature in the presence of phosphorus. A small impact of phosphorus was observed in the case of lignin char yields and the types of pyrolysis decomposition products produced. Levoglucosan is a major component produced in fast pyrolysis of cellulose. Furfural and levoglucosenone become more dominant products upon P-impregnation pointing to new rearrangement and dehydration routes. The P-catalysed xylan decomposition route leads to a much simpler mixture of products, which are dominated by furfural, 3-methyl-2-cyclopenten-1-one and one other unconfirmed product, possibly 3,4-dihydro-2-methoxy-2H-pyran or 4-hydroxy-5,6-dihydro-(2H)-pyran-2-one. Phosphorus-catalysed lignin decomposition also leads to a modified mixture of tar components and desaspidinol as well as other higher molecular weight component become more dominant relative to the methoxyphenyl phenols, dimethoxy phenols and triethoxy benzene. Comparison of the results for Miscanthus lead to the conclusion that the understanding of the fast pyrolysis of biomass can, for the most part, be gained through the study of the individual cell wall components, provided consideration is given to the presence of catalytic components such as phosphorus. (author)

Nowakowski, Daniel J.; Woodbridge, Charles R.; Jones, Jenny M. [Energy and Resources Research Institute, School of Process, Environmental and Materials Engineering (SPEME), University of Leeds, Leeds, LS2 9JT (United Kingdom)

2008-11-15

270

Making Activated Carbon by Wet Pressurized Pyrolysis  

Science.gov (United States)

A wet pressurized pyrolysis (wet carbonization) process has been invented as a means of producing activated carbon from a wide variety of inedible biomass consisting principally of plant wastes. The principal intended use of this activated carbon is room-temperature adsorption of pollutant gases from cooled incinerator exhaust streams. Activated carbon is highly porous and has a large surface area. The surface area depends strongly on the raw material and the production process. Coconut shells and bituminous coal are the primary raw materials that, until now, were converted into activated carbon of commercially acceptable quality by use of traditional production processes that involve activation by use of steam or carbon dioxide. In the wet pressurized pyrolysis process, the plant material is subjected to high pressure and temperature in an aqueous medium in the absence of oxygen for a specified amount of time to break carbon-oxygen bonds in the organic material and modify the structure of the material to obtain large surface area. Plant materials that have been used in demonstrations of the process include inedible parts of wheat, rice, potato, soybean, and tomato plants. The raw plant material is ground and mixed with a specified proportion of water. The mixture is placed in a stirred autoclave, wherein it is pyrolized at a temperature between 450 and 590 F (approximately between 230 and 310 C) and a pressure between 1 and 1.4 kpsi (approximately between 7 and 10 MPa) for a time between 5 minutes and 1 hour. The solid fraction remaining after wet carbonization is dried, then activated at a temperature of 500 F (260 C) in nitrogen gas. The activated carbon thus produced is comparable to commercial activated carbon. It can be used to adsorb oxides of sulfur, oxides of nitrogen, and trace amounts of hydrocarbons, any or all of which can be present in flue gas. Alternatively, the dried solid fraction can be used, even without the activation treatment, to absorb oxides of nitrogen.

Fisher, John W.; Pisharody, Suresh; Wignarajah, K.; Moran, Mark

2006-01-01

271

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

272

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

2013-02-01

273

Catalytic partial oxidation of pyrolysis oils  

Science.gov (United States)

This thesis explores the catalytic partial oxidation (CPO) of pyrolysis oils to syngas and chemicals. First, an exploration of model compounds and their chemistries under CPO conditions is considered. Then CPO experiments of raw pyrolysis oils are detailed. Finally, plans for future development in this field are discussed. In Chapter 2, organic acids such as propionic acid and lactic acid are oxidized to syngas over Pt catalysts. Equilibrium production of syngas can be achieved over Rh-Ce catalysts; alternatively mechanistic evidence is derived using Pt catalysts in a fuel rich mixture. These experiments show that organic acids, present in pyrolysis oils up to 25%, can undergo CPO to syngas or for the production of chemicals. As the fossil fuels industry also provides organic chemicals such as monomers for plastics, the possibility of deriving such species from pyrolysis oils allows for a greater application of the CPO of biomass. However, chemical production is highly dependent on the originating molecular species. As bio oil comprises up to 400 chemicals, it is essential to understand how difficult it would be to develop a pure product stream. Chapter 3 continues the experimentation from Chapter 2, exploring the CPO of another organic functionality: the ester group. These experiments demonstrate that equilibrium syngas production is possible for esters as well as acids in autothermal operation with contact times as low as tau = 10 ms over Rh-based catalysts. Conversion for these experiments and those with organic acids is >98%, demonstrating the high reactivity of oxygenated compounds on noble metal catalysts. Under CPO conditions, esters decompose in a predictable manner: over Pt and with high fuel to oxygen, non-equilibrium products show a similarity to those from related acids. A mechanism is proposed in which ethyl esters thermally decompose to ethylene and an acid, which decarbonylates homogeneously, driven by heat produced at the catalyst surface. Chapter 4 details the catalytic partial oxidation of glycerol without preheat: droplets of glycerol are sprayed directly onto the top of the catalyst bed, where they react autothermally with contact times on the order of tau ? 30 ms. The reactive flash volatilization of glycerol results in equilibrium syngas production over Rh-Ce catalysts. In addition, water can be added to the liquid glycerol, resulting in true autothermal reforming. This highly efficient process can increase H2 yields and alter the H2 to CO ratio, allowing for flexibility in syngas quality depending on the purpose. Chapter 5 details the results of a time on stream experiment, in which optimal syngas conditions are chosen. Although conversion is 100% for 450 hours, these experiments demonstrate the deactivation of the catalyst over time. Deactivation is exhibited by decreases in H2 and CO 2 production accompanied by a steady increase in CO and temperature. These results are explained as a loss of water-gas shift equilibration. SEM images suggest catalyst sintering may play a role; EDS indicates the presence of impurities on the catalyst. In addition, the instability of quartz in the reactor is demonstrated by etching, resulting in a hole in the reactor tube at the end of the experiment. These results suggest prevaporization may be desirable in this application, and that quartz is not a suitable material for the reactive flash volatilization of oxygenated fuels. In Chapter 6, pyrolysis oil samples from three sources - poplar, pine, and hardwoods - are explored in the context of catalytic partial oxidation. Lessons derived from the tests with model compounds are applied to reactor design, resulting in the reactive flash vaporization of bio oils. Syngas is successfully produced, though deactivation due to coke and ash deposition keeps H2 below equlibrium. Coke formation is observed on the reactor walls, but is avoided between the fuel injection site and catalyst by increasing the proximity of these in the reactor design. Low temperatures are maintained in the fuel delivery system utilizing a water-

Rennard, David Carl

274

Techno-economic evaluation of the integrated biosorption-pyrolysis technology for lead (Pb) recovery from aqueous solution.  

Science.gov (United States)

An integrated biosorption-pyrolysis technology was employed to recover Pb from aqueous solution. A series of biosorption, fast pyrolysis and leaching experiments were carried out. The optimum pH and adsorbent dose for Pb adsorption from aqueous solution are 6.0 and 3.0 g L(-1), respectively. The temperature is a key factor influencing the yields of pyrolysis products, and the maximum yield of bio-oil is 45.7% at 773 K. The pyrolysis technology can effectively recover Pb from Pb polluted Typha angustifolia biomass (Pb-TAB) and its recovery efficiency is not notably influenced by temperature. According to the economic evaluation, the biosorption-pyrolysis technology has great techno-economic advantages over the conventional biosorption-leaching technology. PMID:21421305

Liu, Wu-Jun; Zeng, Fan-Xin; Jiang, Hong; Zhang, Xue-Song; Yu, Han-Qing

2011-05-01

275

Quantitative determination of poly(vinylpyrrolidone) by "on-line" pyrolysis coupled to gas chromatography  

Digital Repository Infrastructure Vision for European Research (DRIVER)

"On-line" pyrolysis coupled with gas chromatography (GC) was performed for quantitative determination of poly(vinylpyrrolidone) (PVP) in wastewater sample. Gas chromatography-mass spectrometry (GC-MS) showed that the main product of pyrolysis of PVP, at high temperatures, is N-vinylpyrrolidone (NVP). After that, different amounts of commercial PVP were pyrolyzed in order to establish correlation between the amount of generated NVP (its GC peak area) and the initial mass of pyrolyzed PVP...

Schwarzbauer Jan; Anti? Malia P.; Kronimus Alexander; Anti? Vesna V.

2012-01-01

276

Characteristics of chars produced by pyrolysis following rapid heating of pulverized coal. [104 references  

Energy Technology Data Exchange (ETDEWEB)

A 5.08-cm id pyrolysis furnace has been used to study pyrolysis following rapid heating of size graded pulverized coal particles as a function of isothermal pyrolysis time (0.018 to 1.025 second), particle size (50 to 181 ..mu..m), and parent coal (three lignites). The following experimental conditions were kept constant: Coal feed rate approximately equal to 0.5 g/min; volumetric flow rate of nitrogen temperature = 808/sup 0/C, and pressure = atmospheric. Under these conditions the heating rate of the coal particles in the pyrolysis furnace was of the order of 8 x 10/sup 3/ /sup 0/C/second. The experimental results show: (i) a monotonic change in the physical properties of chars with increasing pyrolysis time; (ii) some dependence of weight loss (i.e. VM yield) on particle size; (iii) that the three lignites undergo pyrolysis to a comparable extent, presumably because of their similar initial chemical composition; (iv) an appreciable influence of temperature and heating rate on weight loss in the Parr VM crucible; and (v) a significant influence of the mode of pyrolysis (i.e. entrained vs fluid bed) on the nature of the char produced. The results from a theoretical treatment of the problem of gas-solid interactions suggest that, in the pyrolysis furnace, all coal particles smaller than 200 ..mu..m in diameter are heated from their initial room temperature to the predetermined gas temperature of 808/sup 0/C so fast that no appreciable gradient is established between their surface and their center.

Nsakala, N.; Walker, Jr., P. L.; Essenhigh, R. H.

1977-02-01

277

Influence of gas-phase reactions on the product yields obtained in the pyrolysis of polyethylene  

Energy Technology Data Exchange (ETDEWEB)

The amount of plastic wastes is growing year after year, and the fraction of plastics in municipal solid wastes (MSW) and in refuse-derived fuels (RDF) is progressively increasing. Pyrolysis and gasification processes appear to be promising routes for the upgrading of solid wastes to more usable and energy dense materials such as gas fuel and/or fuel oil or to high-value feedstocks for the chemical industry. The characterization of the product fractions obtained from the pyrolysis of polyethylene (PE) in a laboratory-scale fixed bed reactor was performed. The experimental system allowed quantitative information to be obtained on the global tar, char, and gas yields. Pyrolysis runs were performed using reactor temperatures ranging between 500 and 800 C. The influence of the residence times in the reactor of the primary volatiles generated by the pyrolysis process was also discussed. The secondary reactivity of the tar originated from PE pyrolysis was examined. A lumped-parameters approach was used in order to evaluate the global kinetic parameters for the gas-phase tar-cracking process. PE tars resulted to be more refractory to thermal decomposition than those obtained in the pyrolysis of biomass and lignocellulosic materials, but more reactive than tars obtained in the pyrolysis of coal.

Cozzani, V.; Tognotti, L. [Univ. degli Studi di Pisa (Italy); Nicolella, C.; Rovatti, M. [Univ. degli Studi di Genova (Italy). Ist. di Ingegneria Chimica e di Processo G.B. Bonino

1997-02-01

278

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

279

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

280

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

 
 
 
 
281

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

282

An ill-posed parabolic evolution system for dispersive deoxygenation-reaeration in water  

Science.gov (United States)

We consider an inverse problem that arises in the management of water resources and pertains to the analysis of surface water pollution by organic matter. Most physically relevant models used by engineers derive from various additions and corrections to enhance the earlier deoxygenation-reaeration model proposed by Streeter and Phelps in 1925, the unknowns being the biochemical oxygen demand (BOD) and the dissolved oxygen (DO) concentrations. The one we deal with includes Taylors dispersion to account for the heterogeneity of the contamination in all space directions. The system we obtain is then composed of two reaction-dispersion equations. The particularity is that both Neumann and Dirichlet boundary conditions are available on the DO tracer while the BOD density is free of any conditions. In fact, for real-life concerns, measurements on the DO are easy to obtain and to save. On the contrary, collecting data on the BOD is a sensitive task and turns out to be a lengthy process. The global model pursues the reconstruction of the BOD density, and especially of its flux along the boundary. Not only is this problem plainly worth studying for its own interest but it could also be a mandatory step in other applications such as the identification of the location of pollution sources. The non-standard boundary conditions generate two difficulties in mathematical and computational grounds. They set up a severe coupling between both equations and they are the cause of the ill-posed data reconstruction problem. Existence and stability fail. Identifiability is therefore the only positive result one can search for; it is the central purpose of the paper. Finally, we have performed some computational experiments to assess the capability of the mixed finite element in missing data recovery.

Azaez, M.; Ben Belgacem, F.; Hecht, F.; Le Bot, C.

2014-01-01

283

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.

K.N. Ismail

2011-01-01

284

Comparison of petroleum generation kinetics by isothermal hydrous and nonisothermal open-system pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

This study compares kinetic parameters determined by open-system pyrolysis and hydrous pyrolysis using aliquots of source rocks containing different kerogen types. Kinetic parameters derived from these two pyrolysis methods not only differ in the conditions employed and products generated, but also in the derivation of the kinetic parameters (i.e., isothermal linear regression and non-isothermal nonlinear regression). Results of this comparative study show that there is no correlation between kinetic parameters derived from hydrous pyrolysis and open-system pyrolysis. Hydrous-pyrolysis kinetic parameters determine narrow oil windows that occur over a wide range of temperatures and depths depending in part on the organic-sulfur content of the original kerogen. Conversely, open-system kinetic parameters determine broad oil windows that show no significant differences with kerogen types or their organic-sulfur contents. Comparisons of the kinetic parameters in a hypothetical thermal-burial history (2.5{sup o}C/my) show open-system kinetic parameters significantly underestimate the extent and timing of oil generation for Type-IIS kerogen and significantly overestimate the extent and timing of petroleum formation for Type-I kerogen compared to hydrous pyrolysis kinetic parameters. These hypothetical differences determined by the kinetic parameters are supported by natural thermal-burial histories for the Naokelekan source rock (Type-IIS kerogen) in the Zagros basin of Iraq and for the Green River Formation (Type-I kerogen) in the Uinta basin of Utah. Differences in extent and timing of oil generation determined by open-system pyrolysis and hydrous pyrolysis can be attributed to the former not adequately natural oil generation conditions, products, and mechanisms. (author)

Lewan, M.D. [U.S. Geological Survey, Denver, CO (United States); Ruble, T.E. [Kirksville, MO (United States)

2002-12-01

285

Study of mobilization and speciation of trace elements in coal pyrolysis  

International Nuclear Information System (INIS)

Various types of coal contain high levels of a number of trace elements. Little is known of the fates of these trace elements during the conversion of coal to liquid and gaseous products. Studies were undertaken of mobilization and speciation of trace elements in coal pyrolysis, one of the major coal conversion processes. The bituminous coal was pyrolyzed to produce liquid and gaseous products. The pyrolysis products were collected in traps in an inert gas stream. In addition mildly hydrogenated coal was prepared by mixing with tetralin, a hydrogen donor solvent, at boiling temperature. In order to characterize each element specifically during pyrolysis, base samples of coal and mildly hydrogenated coal (H-coal) were spiked with heavy metal sulfides, trace metals bound to partially oxidized coal (coal humates), and halide salts prior to carrying out pyrolysis. Eight elements were investigated in this research. They are As, Br, Cl, Co, Cr, Mn, Se, and V. Pre-spiked hydrogenated coal, i.e., pulverized coal spiked with halide salts and heavy metal sulfides then hydrogenated with tetralin, was prepared and studied for the fates of these elements during pyrolysis. Chlorinated and brominated coals were also prepared to compare the volatility differences between organically and inorganically bound halogens during the pyrolysis reaction. These products and the coal char residues were analyzed for the spiked elements mainly by neutron activation analysis for the spiked elementactivation analysis for the spiked elements to determine their degree of volatility. Volatility and recovery (mass balance) will be discussed for those elements that appeared highly volatile during pyrolysis. In order to understand the halogenated compounds in the pyrolysis products, gas chromatograms were taken to the collected pyrolysis products of coal, hydrogenated coal, NaCl spiked coal, NaBr spiked coal, chlorinated coal, and brominated coal

286

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 1000C 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

2009-02-01

287

Reductive pyrolysis study of biodesulfurized subbituminous coal  

Energy Technology Data Exchange (ETDEWEB)

Biodesulfurization is one of the perspective methods for production of friendly fuels. Reductive pyrolysis in mode of atmospheric pressure temperature programmed reduction (AP-TPR) combined with varied detection systems gave us possibility to obtain more satisfactory explanation of biodesulfurization effects. AP-TPR coupled 'on-line' and 'off-line' with potentiometry, mass spectrometry and GC/MS analysis with inner sulfur standards for quantification were applied. Subbituminous coal from 'Pirin' basin, Bulgaria was treated by three different types of microorganisms with maximal desulfurization effect for total (26%) and organic sulfur (13%). Namely, two types white rot fungi - 'Trametes Versicolor', 'Phanerochaeta Chrysosporium' and one mixed bacterial culture were used. Improved sulfur balance determination was registered. 10 refs., 3 tabs.

S.P. Marinov; L. Gonsalvesha; M. Stefanova; Y. Yueeriem; A.G. Dumanli; N. Kolankaya; M. Sam; R. Carleer; G. Reggers; J. Yperman [Bulgarian Academy of Sciences, Sofia (Bulgaria). Institute of Organic Chemistry

2007-07-01

288

Thermochemical Behavior of Tris(2-Butoxyethyl) Phosphate (TBEP) during Co-pyrolysis with Biomass.  

Science.gov (United States)

Co-pyrolysis of plastic waste and wood biomass to recover valuable chemicals is a cost-effective waste-recycling technology. However, widely used organophosphate ester additives in plastic, such as tris(2-butoxyethyl) phosphate (TBEP), can form diverse phosphorus (P)-containing species. These P-containing compounds can pose new environmental challenges when the biochar is reused. In this study, a mixture of TBEP and lignin was used to simulate the feedstock of plastic waste and wood biomass, and the thermochemical behavior of TBEP in slow pyrolysis (20 K min(-1)) and fast pyrolysis at 400-600 C was investigated. The results show that low temperature in fast pyrolysis favors the enrichment of P in char. Up to 76.6% of initial P in the feedstock is retained in the char resulting from 400 C, while only 51% is retained in the char from 600 C. Slow pyrolysis favors the formation of stable P species regardless of the temperature; only 7% of the P retained in the char is extractable from char from slow pyrolysis, while 20-40% of P can be extracted from char resulting from fast pyrolysis. The addition of CaCl2 and MgCl2 can significantly increase the fraction of P retained in the char by the formation of Ca, Mg-P compounds. Online TG-FTIR-MS analysis suggests that TBEP undergoes decomposition through different temperature-dependent pathways. The P-containing radicals react with the aromatic rings produced by the pyrolysis of lignin to form Ar-P species, which is an important factor influencing the distribution and stabilization of P in char. PMID:25154038

Qian, Ting-Ting; Li, De-Chang; Jiang, Hong

2014-09-16

289

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

2013-01-01

290

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 C, 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

291

Advances in Modeling and Simulation of Biomass Pyrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available The various aspects of modeling and simulation work carried out so far in biomass pyrolysis since 1946 have been extensively reviewed in the present study. Biomass pyrolysis, one of the few non conventional energy routes, is highly promising and capable of handling the current energy crisis successfully for the present and in the near future. Pyrolysis as a stand alone or as the core of biomass gasification process is complex in nature, the understanding and knowledge of this multifaceted phenomenon can heavily influence the efficiency and effectiveness of the whole gasification process. Even though, the modeling of biomass pyrolysis process was initiated during 1940`s gradual changes, improvements and alternates have been carried out throughout these years. All these years, various modeling approaches were adopted, different kinetic schemes were proposed, diverse numerical schemes were followed and range of parameters were implemented, all these have developed a baffling picture over the subject. The complexity of the process, as such the large number of components involved in the intermediates and end products; the dependency of the process over numerous parameters namely the temperature, space and time dependent physical, thermodynamic and transport properties, the particle shape, size, shrinkage factors and moisture content all these justify even today the necessity and requirement of research for further improvement and enrichment in the modeling and simulation fronts of this process. This study sums up the work carried out in literature on modeling and simulation of wood pyrolysis and suggests new research directions and approaches necessarily to be made up in future.

N. Prakash

2009-01-01

292

Pyrolysis of polyolefins for increasing the yield of monomers recovery  

International Nuclear Information System (INIS)

Highlights: ? Thermal and catalytic pyrolysis of mixed polyolefins in fluidized bed has been studied. ? We tested applicability of a commercial ZieglerNatta catalyst (ZN: TiCl4/MgCl2). ? The catalyst has a strong influence on product distribution, increasing gas fraction. ? At 650 C the monomer generation increased by 55% when the catalyst was used. ? We showed the concept of treatment of mixed polyolefins without a need of separation. - Abstract: 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 ZieglerNatta (ZN): TiCl4/MgCl2 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 ZN 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 13 kg/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.

293

Fixed-bed hydrogen pyrolysis of rapeseed: product yields and compositions  

International Nuclear Information System (INIS)

The fixed-bed hydro pyrolysis tests have been conducted on a sample of rapeseed to investigate the effect of hydro pyrolysis on the yields and chemical structures of bio-oils, with a view to improving overall product quality. A ammonium dioxydithiomolybdenate catalyst has been used in some tests to further increase conversion. The maximum bio-oil yield of 84% was obtained in hydrogen atmosphere (with catalyst) at hydrogen pressure of 15 MPa, hydrogen flow rate of 10 dm3min-1, hydro pyrolysis temperature of 520 degree C, and heating rate of 5 oCmin-1. Then this bio-oil was characterized by elemental analysis and some spectroscopic and chromatographic techniques. And finally, this bio-oil yield and chemical composition compared with oil obtained from fast pyrolysis condition

294

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

295

Mechanistic investigation into the formation of polycyclic aromatic hydrocarbons from the pyrolysis of plant steroids  

Energy Technology Data Exchange (ETDEWEB)

There have been many studies on the pyrolysis of biomass model compounds but most have not been performed under the high heating rate, short residence time conditions currently used in the thermochemical conversion of biomass. In this investigation, the pyrolysis of plant steroids is investigated by flash vacuum pyrolysis (FVP) and flow pyrolysis at residence times of 0.1-2.0 s and temperatures of 550-800{degree}C to determine if the native cyclic ring structure in the steroid leads to the formation of polycyclic aromatic hydrocarbons (PAHs) or whether PAHs are formed by pyrosynthesis. FVP of stigmasterol stigmasterol acetate, {beta}-sitosterol and stigmasta-3,5-diene at 700{degree}C showed that PAHs, such as acenaphthylene, phenanthrene, anthracene, pyrene, chrysene, benz(a)anthracene, and their monomethylated derivatives were formed in the absence of bimolecular reactions, and the yield of PAHs was dependent of the structure of the steroid. Similar products were found in the flow pyrolysis of stigmasterol, and the yields of PAHs were found to increase with increasing temperature and residence time. Thermochemical kinetic estimates were used to postulate pathways for the formation of the primary pyrolysis products. 66 refs., 9 figs., 7 tabs.

Britt, P.F.; Buchanan, A.C. III; Kidder, M.M.; Owens, C.; Ammann, J.R.; Skeen, J.T.; Luo, L. [Oak Ridge National Lab., Oak Ridge, TN (United States). Chemical and Analytical Sciences

2001-10-09

296

Pyrolysis of furniture and tire wastes in a flaming pyrolyzer minimizes discharges to the environment  

Energy Technology Data Exchange (ETDEWEB)

Wood furniture waste and scrap tires were pyrolysed in a pilot scale batch flaming pyrolyzer. The effect of temperature, fuel/air ratio, and reaction times on the temperature distribution, gas and char pyrolysis yields, oxygen levels, SO{sub 2} and NO{sub x} emissions, and pyrolysis gas composition were studied. Low emission levels of NO{sub x}, SO{sub 2} and heavy metals were observed in the pyrolysis of wastes with high content of nitrogen (chipboard), sulfur, or heavy metals (scrap tires), respectively. The main components of the pyrolysis gas were acetylene, methane, and carbon monoxide. Gas chromatographic, GC-MS, and FT-IR studies of the heavy hydrocarbons fraction of pyrolysis gas were consistent with each other and showed the presence of alcohols, carboxylic derivatives, heterocyclic and phenolic compounds in furniture waste pyrolysate, and aromatic compounds in tires pyrolysate. Kovats indices for GC-MS retention times were calculated for a series of organic compounds of environmental interest. Organic compounds in the pyrolysate were identified from mass spectra and by comparison of retention times with authentic standards or published Kovats indices. The heating value of the pyrolysis gas from furniture waste and scrap tire was 8.7 and 5.6 MJ/m{sup 3} respectively. 47 refs., 10 figs., 9 tabs.

Sainz-Diaz, C.I.; Kelly, D.R.; Avenell, C.S.; Griffiths, A.G. [C.S.I.C., Granada (Spain). Estacion Experimental del Zaidin

1997-09-01

297

Catalytic pyrolysis of microalgae to high-quality liquid bio-fuels  

International Nuclear Information System (INIS)

The pyrolytic conversion of chlorella algae to liquid fuel precursor in presence of a catalyst (Na2CO3) has been studied. Thermal decomposition studies of the algae samples were performed using TGA coupled with MS. Liquid oil samples were collected from pyrolysis experiments in a fixed-bed reactor and characterized for water content and heating value. The oil composition was analyzed by GC-MS. Pretreatment of chlorella with Na2CO3 influences the primary conversion of chlorella by shifting the decomposition temperature to a lower value. In the presence of Na2CO3, gas yield increased and liquid yield decreased when compared with non-catalytic pyrolysis at the same temperatures. However, pyrolysis oil from catalytic runs carries higher heating value and lower acidity. Lower content of acids in the bio-oil, higher aromatics, combined with higher heating value show promise for production of high-quality bio-oil from algae via catalytic pyrolysis, resulting in energy recovery in bio-oil of 40%. -- Highlights: ? The pyrolytic catalytic conversion of chlorella algae to liquid fuel precursor. ? Na2CO3 as a catalyst for the primary conversion of chlorella. ? Pyrolysis oil from catalytic runs carries higher heating value and lower acidity. ? High-quality bio-oil from algae via catalytic pyrolysis with energy recovery in bio-oil of 40%.

298

Characterization of sulfonated azo dyes and aromatic amines by pyrolysis gas chromatography/mass spectrometry.  

Science.gov (United States)

Sixteen sulfonated and unsulfonated azo dyes as well as eleven sulfonated and unsulfonated aromatic amines were analyzed and qualitatively characterized by means of pyrolysis gas chromatography/mass spectrometry at different temperatures. Aniline and aminonaphthalene were found to be the dominant pyrolysis products of sulfonated aromatic amines and dyes. Azo dye and dye class specific key compounds such as benzidine, vinyl-p-base and 4-aminoazobenzene could be identified by pyrolysis gas chromatography/mass spectrometry of commercial acid, cationic, direct, reactive and solvent dyes. 500 degrees C was the optimal pyrolysis temperature for most of the pyrolyzed compounds. The method was applied to a dried sample of a textile wastewater concentrate from a dyeing process. Reactive azo dyes of the group of Remazol dyes and anthraquinone dyes could be identified as the major compounds of the sample. The finding of caprolactam (a printing additive) suggests that the wastewater contained effluent from a process of heat-activated printing with reactive dyes. p-Chloraniline, a banned aromatic amine, was identified. Chemical reduction of the wastewater sample prior to pyrolysis resulted in the release of volatile aromatic amines and aided the classification of several products of pyrolysis. PMID:17579845

Rehorek, Astrid; Plum, Alexander

2007-08-01

299

Multisteps Global Kinetic Analysis of MSW Slow Pyrolysis  

Directory of Open Access Journals (Sweden)

Full Text Available The goal of this research is to find relationships between single components slow pyrolysis characteristics and mixed component slow pyrolysis characteristics of segregated municipal solid wastes (MSW. The material of this research consists of organic wastes (bamboo wastes and banana leaves wastes and inorganic wastes (styrofoam wastes and snack wrapping wastes. The materials which used to study were the unprosessing waste. The samples were collected, dried and crushed until passing 20 mesh shieves then characterized in self manufactured macro balance. The thermogravimetry analyses were done to find the MSW slow pyrolysis characteristics. The 20 gram sample was placed in the furnace whose temperature is increased with 10 0C/min heating rate until reached 400 0 final temperature and held for 30 minutes before the sample is cooled into room temperature. One hundred ml/min nitrogen introduced from the bottom of furnace as a swept gas. The results of the research show that the global kinetic method could be used to predict the MSW single component activation energy but it should be modified to calculate the mixed sample activation energy . The predictive activation energy values which calculated based on weighed sum of single component have 18.5 % deviations if compared with experimental result.

Dwi Aries Himawanto

2013-12-01

300

Studies on Taxol Biosynthesis: Preparation of Taxadiene-diol- and triol-Derivatives by Deoxygenation of Taxusin  

Science.gov (United States)

The putative taxol biosynthesis metabolites, taxa-4(20),11(12)-diene-5?, 13? -diol (7), taxa-4(20),11(12)-diene-5?, 9?, 13?-triol (9), and taxa-4(20),11(12)-diene-5?, 10?, 13?-triol (10), have been prepared by Barton deoxygenation of the C-9 and C10-hydroxyl groups of protected derivatives of taxusin, a major taxoid metabolite isolated from Yew heart wood. The synthetic protocol devised, is amenable for the preparation of isotopically labeled congeners that will be useful to probe further intermediate steps in the biosynthesis of taxol. PMID:19122848

Li, Hui; Horiguchi, Tohru; Croteau, Rodney

2008-01-01

 
 
 
 
301

Aromatics and phenols from catalytic pyrolysis of Douglas fir pellets in microwave with ZSM-5 as a catalyst  

Energy Technology Data Exchange (ETDEWEB)

Microwave assisted catalytic pyrolysis was investigated to convert Douglas fir pellets to bio-oils by a ZSM-5 Zeolite catalyst. A central composite experimental design (CCD) was used to optimize the catalytic pyrolysis process. The effects of reaction time, temperature and catalyst to biomass ratio on the bio-oil, syngas, and biochar yields were determined. GC/MS analysis results showed that the bio-oil contained a series of important and useful chemical compounds. Phenols, guaiacols, and aromatic hydrocarbons were the most abundant compounds which were about 50-82 % in bio-oil depending on the pyrolysis conditions. Comparison between the bio-oils from microwave pyrolysis with and without catalyst showed that the catalyst increased the content of aromatic hydrocarbons and phenols. A reaction pathway was proposed for microwave assisted catalyst pyrolysis of Douglas fir pellets.

Wang, Lu; Lei, Hanwu; Ren, Shoujie; Bu, Quan; Liang, Jing; Wei, Yi; Liu, Yupeng; Lee, Guo-Shuh J.; Chen, Shulin; Tang, Juming; Zhang, Qin; Ruan, Roger

2012-11-04

302

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

Directory of Open Access Journals (Sweden)

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

Mohamad A. Sukiran

2011-01-01

303

Catalytic conversion of biomass by fast pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The effect of various catalysts on the fast pyrolysis of biomass at short residence times was investigated. Both rapid heating and short residence times of gases were employed in a single-step pyrolysis-gasification of Douglas fir sawdust in a free-falling system. The influence of different catalysts (Na/sub 2/CO/sub 3/, CaCO/sub 3/, NaHCO/sub 3/, KHCO/sub 3/, NaCl, KCl, CaCl/sub 2/, ZnCl/sub 2/, H/sub 3/PO/sub 4/, (NH/sub 4/)/sub 2/HPO/sub 4/, H/sub 2/C/sub 2/O/sub 4/, Ni(CH/sub 3/COO)/sub 2/) was investigated both for dry materials and 50% moisture contents over the temperature range 700 to 900/sup 0/C. Impregnation of wood with catalysts was achieved by soaking the sawdust in an aqueous solution of catalyst. The impregnation was 0.01 mol of catalyst per mole of Douglas fir (CH/sub 1/ /sub 44/O/sub 0/ /sub 66/ = 24g). Tables of gas products (H/sub 2/, CO, CO/sub 2/, CH/sub 4/, C/sub 2/H/sub 4/, C/sub 2/H/sub 2/), overall formulae of residues, mass yield and heating values of gases are given for the different catalysts. Impregnated wood with some catalysts gives better results for the gasification yield and (H/sub 2/)/(CO) ratio. 1 figure, 11 tables.

Rolin, A.; Richard, C.; Masson, D.; Deglise, X.

1983-07-01

304

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

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Full Text Available Sulfated titania (SO42-/TiO2 was prepared and used for catalytic fast pyrolysis of cellulose to produce levoglucosenone (LGO, a valuable anhydrosugar product. Analytical pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS technique was employed in this study to achieve the catalytic fast pyrolysis of cellulose and on-line analysis of the pyrolysis vapors. Experiments were performed to investigate the effects of several factors on the LGO production, i.e. pyrolysis temperature, cellulose/catalyst ratio, TiO2 crystal type, and pyrolysis time. The results indicated that the SO42-/TiO2 catalyst lowered the initial cellulose decomposition temperature and altered the pyrolytic product significantly. Levoglucosan (LG was the most abundant product in the non-catalytic process, while levoglucosenone (LGO was the major product in the catalytic process. The maximal LGO yield was obtained at the set pyrolysis temperature of 400 C, while the highest LGO content was obtained at 350 C, with the peak area% over 50%. In addition, the SO42-/TiO2 (anatase was confirmed the best catalyst for the LGO production.

Qiang Lu,

2012-05-01

305

Pyrolysis of two different biomass samples in a fixed-bed reactor combined with two different catalysts  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of Euphorbia rigida and sesame stalk biomass samples with two selected commercial catalyst, namely DHC-32 and HC-K 1.3Q, have been conducted in a fixed-bed reactor. The effect of different catalysts and their ratio (5, 10 and 20% w/w) and pyrolysis temperature (500 and 750{sup o}C) on the pyrolysis product yields were investigated and the obtained results were compared with similar experiments without catalyst. Bio-oil yield was increased comparing with non-catalytic experiments, at final pyrolysis temperature of 500{sup o}C for both biomass samples and catalysts. In the catalytic experiments; when the temperature reached to 750{sup o}C, although bio-oil product yield was reduced, the gas product yield was increased comparing with non-catalytic experiments. The pyrolysis oils were examined using spectroscopic and chromatographic analyses and then fractioned by column chromatography. Although the aliphatic and aromatic fractions were decreased and polar fraction was increased with catalytic pyrolysis of E. rigida; an opposite trend was observed in the sesame stalk pyrolysis oil, comparing with non-catalytic results. Obtained results were compared with petroleum fractions and determined the possibility of being a potential source of renewable fuels. 35 refs., 15 figs., 3 tabs.

Funda Ates; Ayse E. Putun; Ersan Putun [Anadolu University, Eskisehir (Turkey). Department of Chemical Engineering, Faculty of Engineering and Architecture

2006-09-15

306

Element and PAH constituents in the residues and liquid oil from biosludge pyrolysis in an electrical thermal furnace.  

Science.gov (United States)

Biosludge can be pyrolyzed to produce liquid oil as an alternative fuel. The content of five major elements, 22 trace elements and 16 PAHs was investigated in oven-dried raw material, pyrolysis residues and pyrolysis liquid products. Results indicated 39% carbon, 4.5% hydrogen, 4.2% nitrogen and 1.8% sulfur were in oven dried biosludge. Biosludge pyrolysis, carried out at temperatures from 400 to 800C, corresponded to 34-14% weight in pyrolytic residues, 32-50% weight in liquid products and 31-40% weight in the gas phase. The carbon, hydrogen and nitrogen decreased and the sulfur content increased with an increase in the pyrolysis temperature at 400-800C. NaP (2 rings) and AcPy (3 rings) were the major PAHs, contributing 86% of PAHs in oven-dried biosludge. After pyrolysis, the PAH content increased with the increase of pyrolysis temperature, which also results in a change in the PAH species profile. In pyrolysis liquid oil, NaP, AcPy, Flu and PA were the major species, and the content of the 16 PAHs ranged from 1.6 to 19 ?g/ml at pyrolysis temperatures ranging from 400 to 800C. Ca, Mg, Al, Fe and Zn were the dominant trace elements in the raw material and the pyrolysis residues. In addition, low toxic metal (Cd, V, Co, and Pb) content was found in the liquid oil, and its heat value was 7,800-9,500 kcal/kg, which means it can be considered as an alternative fuel. PMID:24631616

Chiang, Hung-Lung; Lin, Kuo-Hsiung; Lai, Nina; Shieh, Zhu-Xin

2014-05-15

307

Pyrolysis kinetics of algal consortia grown using swine manure wastewater.  

Science.gov (United States)

In this study, pyrolysis kinetics of periphytic microalgae consortia grown using swine manure slurry in two seasonal climatic patterns in northwest Arkansas were investigated. Four heating rates (5, 10, 20 and 40 C min(-1)) were used to determine the pyrolysis kinetics. Differences in proximate, ultimate, and heating value analyses reflected variability in growing substrate conditions, i.e., flocculant use, manure slurry dilution, and differences in diurnal solar radiation and air temperature regimes. Peak decomposition temperature in algal harvests varied with changing the heating rate. Analyzing pyrolysis kinetics using differential and integral isoconversional methods (Friedman, Flynn-Wall-Ozawa, and Kissinger-Akahira-Sunose) showed strong dependency of apparent activation energy on the degree of conversion suggesting parallel reaction scheme. Consequently, the weight loss data in each thermogravimetric test was modeled using independent parallel reactions (IPR). The quality of fit (QOF) for the model ranged between 2.09% and 3.31% indicating a good agreement with the experimental data. PMID:25105272

Sharara, Mahmoud A; Holeman, Nathan; Sadaka, Sammy S; Costello, Thomas A

2014-10-01

308

A study of paint sludge deactivation by pyrolysis reactions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The production of large quantities of paint sludge is a serious environmental problem. This work evaluates the use of pyrolysis reaction as a process for deactivating paint sludge that generates a combustible gas phase, a solvent liquid phase and an inert solid phase. These wastes were classified in [...] to three types: water-based solvent (latex resin) and solvents based on their resins (alkyd and polyurethane). An electrically heated stainless steel batch reactor with a capacity of 579 mL and a maximum pressure of 30 atm was used. Following the reactor, a flash separator, which was operated at atmospheric pressure, partially condensed and separated liquid and gas products. Pressure and temperature were monitored on-line by a control and data acquisition system, which adjusted the heating power supplied to the pyrolysis reactor. Reactions followed an experimental design with two factors (reaction time and temperature) and three levels (10, 50 and 90 minutes; 450, 550 and 650C). The response variables were liquid and solid masses and net heat of combustion. The optimal operational range for the pyrolysis process was obtained for each response variable. A significant reduction in total mass of solid waste was obtained.

L.A.R., Muniz; A.R., Costa; E., Steffani; A.J., Zattera; K., Hofsetz; K., Bossardi; L., Valentini.

2003-03-01

309

A study of paint sludge deactivation by pyrolysis reactions  

Directory of Open Access Journals (Sweden)

Full Text Available The production of large quantities of paint sludge is a serious environmental problem. This work evaluates the use of pyrolysis reaction as a process for deactivating paint sludge that generates a combustible gas phase, a solvent liquid phase and an inert solid phase. These wastes were classified into three types: water-based solvent (latex resin and solvents based on their resins (alkyd and polyurethane. An electrically heated stainless steel batch reactor with a capacity of 579 mL and a maximum pressure of 30 atm was used. Following the reactor, a flash separator, which was operated at atmospheric pressure, partially condensed and separated liquid and gas products. Pressure and temperature were monitored on-line by a control and data acquisition system, which adjusted the heating power supplied to the pyrolysis reactor. Reactions followed an experimental design with two factors (reaction time and temperature and three levels (10, 50 and 90 minutes; 450, 550 and 650degreesC. The response variables were liquid and solid masses and net heat of combustion. The optimal operational range for the pyrolysis process was obtained for each response variable. A significant reduction in total mass of solid waste was obtained.

Muniz L.A.R.

2003-01-01

310

A study of paint sludge deactivation by pyrolysis reactions  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english The production of large quantities of paint sludge is a serious environmental problem. This work evaluates the use of pyrolysis reaction as a process for deactivating paint sludge that generates a combustible gas phase, a solvent liquid phase and an inert solid phase. These wastes were classified in [...] to three types: water-based solvent (latex resin) and solvents based on their resins (alkyd and polyurethane). An electrically heated stainless steel batch reactor with a capacity of 579 mL and a maximum pressure of 30 atm was used. Following the reactor, a flash separator, which was operated at atmospheric pressure, partially condensed and separated liquid and gas products. Pressure and temperature were monitored on-line by a control and data acquisition system, which adjusted the heating power supplied to the pyrolysis reactor. Reactions followed an experimental design with two factors (reaction time and temperature) and three levels (10, 50 and 90 minutes; 450, 550 and 650C). The response variables were liquid and solid masses and net heat of combustion. The optimal operational range for the pyrolysis process was obtained for each response variable. A significant reduction in total mass of solid waste was obtained.

L.A.R., Muniz; A.R., Costa; E., Steffani; A.J., Zattera; K., Hofsetz; K., Bossardi; L., Valentini.

311

Method of producing pyrolysis gases from carbon-containing materials  

Science.gov (United States)

A gasification process of improved efficiency is disclosed. A dual bed reactor system is used in which carbon-containing feedstock materials are first treated in a gasification reactor to form pyrolysis gases. The pyrolysis gases are then directed into a catalytic reactor for the destruction of residual tars/oils in the gases. Temperatures are maintained within the catalytic reactor at a level sufficient to crack the tars/oils in the gases, while avoiding thermal breakdown of the catalysts. In order to minimize problems associated with the deposition of carbon-containing materials on the catalysts during cracking, a gaseous oxidizing agent preferably consisting of air, oxygen, steam, and/or mixtures thereof is introduced into the catalytic reactor at a high flow rate in a direction perpendicular to the longitudinal axis of the reactor. This oxidizes any carbon deposits on the catalysts, which would normally cause catalyst deactivation.

Mudge, Lyle K. (Richland, WA); Brown, Michael D. (West Richland, WA); Wilcox, Wayne A. (Kennewick, WA); Baker, Eddie G. (Richland, WA)

1989-01-01

312

Pharmacological modification of oxygen affinity improves deformability of deoxygenated sickle erythrocytes: a possible therapeutic approach to sickle cell disease.  

Science.gov (United States)

1. The formation of polymerized haemoglobin S in sickle cells is critically dependent on the concentration of deoxygenated haemoglobin so that compounds which increase the oxygen affinity of haemoglobin S are potential anti-sickling agents. 2. BW12C [5-(2-formyl-3-hydroxyphenoxy)pentanoic acid] and BWA589C [4-(2-formyl-3-hydroxyphenoxymethyl)benzoic acid] are aromatic benzaldehydes that cause a dose-dependent left-shift of the oxygen saturation curve of haemoglobin S by stabilization of its oxy-(R)-conformation. 3. A 5 micron pore filtration method, which is highly sensitive to polymerization of haemoglobin S, was used to demonstrate a significant improvement in the deformability of deoxygenated sickle erythrocytes at concentrations (0.75-1.5 mmol/l] of BW12C and BWA589C that are achievable in vivo. Both compounds may therefore be of value for the treatment of sickle cell disease. 4. Filtration of sickle cells through pores of 5 microns diameter is a sensitive technique for evaluating the rheological effects of potential anti-sickling compounds. PMID:2714049

Keidan, A J; Sowter, M C; Johnson, C S; Marwah, S S; Stuart, J

1989-04-01

313

Studies on Catalytic Pyrolysis of Mustard Press Cake with NaCl  

Directory of Open Access Journals (Sweden)

Full Text Available Under this present investigation, non-catalytic and catalytic pyrolysis of mustard press cake (MPC was conducted in a 50 mm diameter and 640 mm long semi-batch pyrolyser in the temperature range of 673K to 1173K in a nitrogen atmosphere. Effects of temperature on yields of products, namely, char, pyro-oil and gas obtained from primary pyrolysis of MPC have been investigated. The kinetic rate constants of volatiles and char formations were determined in the temperature range under the study. The activation energies and pre-exponential factors were determined. The catalytic effects of NaCl on the pyrolysis of MPC have also been investigated at three different temperatures namely, 673K, 773K and 873K. Catalyst loading was varied from 5-15% (w/w biomass. The product yields of catalytic and non-catalytic pyrolysis of MPC was compared. The activation energies of catalytic pyrolysis have been observed to be low in comparison to non-catalytic ones.

Aparna Sarkar1

2014-06-01

314

Kinetics of coal pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

This report contains results of a coordinated, multi-laboratory investigation of coal devolatilization. Data is reported pertaining to the devolatilization for bituminous coals over three orders of magnitude in apparent heating rate (100 to 100,000 + {degree}C/sec), over two orders of magnitude in particle size (20 to 700 microns), final particle temperatures from 400 to 1600{degree}C, heat transfer modes ranging from convection to radiative, ambient pressure ranging from near vacuum to one atmosphere pressure. The heat transfer characteristics of the reactors are reported in detail. It is assumed the experimental results are to form the basis of a devolatilization data base. Empirical rate expressions are developed for each phase of devolatilization which, when coupled to an awareness of the heat transfer rate potential of a particular devolatilization reactor, indicate the kinetics emphasized by a particular system reactor plus coal sample. The analysis indicates the particular phase of devolatilization that will be emphasized by a particular reactor type and, thereby, the kinetic expressions appropriate to that devolatilization system. Engineering rate expressions are developed from the empirical rate expressions in the context of a fundamental understanding of coal devolatilization developed in the course of the investigation. 164 refs., 223 figs., 44 tabs.

Seery, D.J.; Freihaut, J.D.; Proscia, W.M. (United Technologies Research Center, East Hartford, CT (USA)); Howard, J.B.; Peters, W.; Hsu, J.; Hajaligol, M.; Sarofim, A. (Massachusetts Inst. of Tech., Cambridge, MA (USA)); Jenkins, R.; Mallin, J.; Espindola-Merin, B. (Pennsylvania State Univ., University Park, PA (USA)); Essenhigh, R.; Misra, M.K. (Ohio State Univ., Columbus, OH (USA))

1989-07-01

315

Cohesive coal grain bonding during pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Coal grain adhesion during pyrolysis was investigated under laboratory conditions. An iron rod was heated to 850 C. A hot iron rod was indented 50 mm deep into a mixture of coal grains crushed to below 3 mm. Rate of coal grain buildup (adhesion) on the iron rod was analyzed considering coal type and additive. The following coal groups were used: G6, Zh21, K14 and OS6. Coal blends consisting of one coal type only, and coal mixtures with or without petroleum additives were used. Coal type influenced coal grain buildup (reflecting adhesion of coal grains bonded by caking), reaching a maximum for fat coal. Increasing iron rod temperature influenced coal grain bonding. In the case of gas coal, the bonding was regular within the whole temperature range; in the case of lean caking coal and coking coal, grain bonding was more intensive at higher temperatures. Use of binary mixtures increased the bonding rate. Use of petroleum products as binders significantly increased coal grain bonding. 5 refs.

Biryukov, Yu.V.; Slyn' ko, V.P.; Ol' fert, A.I.; Malevich, V.K.; Latypov, R.T.

1988-08-01

316

Preparation of brightness stabilization agent for lignin containing pulp from biomass pyrolysis oils  

Science.gov (United States)

A process for producing a brightness stabilization mixture of water-soluble organic compounds from biomass pyrolysis oils comprising: a) size-reducing biomass material and pyrolyzing the size-reduced biomass material in a fluidized bed reactor; b) separating a char/ash component while maintaining char-pot temperatures to avoid condensation of pyrolysis vapors; c) condensing pyrolysis gases and vapors, and recovering pyrolysis oils by mixing the oils with acetone to obtain an oil-acetone mixture; d) evaporating acetone and recovering pyrolysis oils; e) extracting the pyrolysis oils with water to obtain a water extract; f) slurrying the water extract with carbon while stirring, and filtering the slurry to obtain a colorless filtrate; g) cooling the solution and stabilizing the solution against thermally-induced gelling and solidification by extraction with ethyl acetate to form an aqueous phase lower layer and an organic phase upper layer; h) discarding the upper organic layer and extracting the aqueous layer with ethyl acetate, and discarding the ethyl acetate fraction to obtain a brown-colored solution not susceptible to gelling or solidification upon heating; i) heating the solution to distill off water and other light components and concentrating a bottoms fraction comprising hydroxyacetaldehyde and other non-volatile components having high boiling points; and j) decolorizing the stabilized brown solution with activated carbon to obtain a colorless solution.

Agblevor, Foster A. (Blacksburg, VA); Besler-Guran, Serpil (Flemington, NJ)

2001-01-01

317

STEPWISE ISOTHERMAL FAST PYROLYSIS (SIFP OF BIOMASS PART I. SIFP OF PINE SAWDUST  

Directory of Open Access Journals (Sweden)

Full Text Available Pyrolysis of pine wood sawdust was carried out using stepwise isothermal fast pyrolysis (SIFP, focusing on the search of reaction conditions to obtain chemicals in good yields from biomass. SIFP consists of successive isothermal fast pyrolysis reactions, where solid products obtained in the previous isothermal fast pyrolysis become the substrate of the subsequent reaction at a higher temperature. This article reports results obtained by SIFP of pine sawdust between 200 and 600C using 100C intervals under vacuum (0.2 mm, using nitrogen as carrier gas. Both sets of reactions made it possible to obtain most of the compounds that have been previously described in conventional fast pyrolysis experiments; however this system produces a smaller number of chemical compounds in each isothermal FP, making it easier to obtain determined chemicals with industrial or research value. Maximum yield of liquid products occurred at 300C, giving around 30% of bio-oil, which contained mainly phenols and furan derivatives. Liquid-Liquid extraction led to a rich mixture of phenol derivatives. Results showed that SIFP is an interesting technique to obtain enriched fractions of products derived from biomass pyrolysis.

Patricia Lpez Rivilli

2011-05-01

318

Study on thermal co-pyrolysis of jatropha deoiled cake and polyolefins.  

Science.gov (United States)

Three plastics, high density polyethylene (HDPE), polypropylene (PP) and polystyrene (PS), were individually co-pyrolysed with deoiled cake of jatropha (JC) at 400 and 450C in a batch reactor in the presence of nitrogen under atmospheric pressure to produce modified liquid fractions. At higher temperature (450C), the yield of liquid fractions by the pyrolysis of plastics (HDPE, PP and PS) alone was found to increase by 11, 12.5 and 11% for HDPE, PP and PS, respectively. Furthermore, the gaseous fraction increased by 1.3 to 2.6% while the residue generation reduced by 12.3 to 15.1%. In comparison with only plastics pyrolysis, the yield of the liquid fraction improved by 2.0 to 4.9% for their co-pyrolysis with JC. Gas chromatography-mass spectrometry analyses demonstrated that the co-processing afforded a reduction of paraffin and olefins in the liquid fractions for all of the experiments. This reduction was found to be in the order of PS?>?PP?>?HDPE. Furthermore, the proportion of oxygenates in the liquid product increased in the order of PP?>?HDPE?>?PS. Physical characteristics such as oxygenates, water contents, acid values and viscosity increased during the co-pyrolysis of plastics and JC in contrast to the liquid fractions obtained from the pyrolysis of pure plastics. Furthermore, co-pyrolysis offered a reduction in calorific values. PMID:21628346

Rotliwala, Yogesh C; Parikh, Parimal A

2011-12-01

319

Production of bran castor biochar through slow pyrolysis  

Science.gov (United States)

Pyrolysis is a thermal process of great importance in the present context, since it constitutes a significant alternative to adequate use of organic waste. The principal products obtained in the pyrolysis of discarded biomass are bio-oil, biogas and biochar. Biochar, in turn, may play a relevant role when applied to the soil to sequester carbon and as a soil conditioner, a material comparable to organic matter of Indians Black Earths from the Amazon Region [1]. Seeking to determine the best methods of preparation of biochar, we studied the pyrolysis of bran castor residue of the Brazilian biodiesel industry. Eight samples, from FM1 to FM8, were prepared in a factorial design 23 using two temperature (300 and 350 C), two heating velocity (5 and 10 C min-1) and two period of heating (30 and 60 min). The eight samples were studied using the spectroscopy: EPR, FTIR, RMN, XPS, and elemental analysis. By elemental analysis, the samples that keep for lower temperature of pyrolysis, 300 C, showed H/C and N/C ratios greater than the samples of 350 C. That higher value can be attributed to chemical structure more aliphatic than aromatic mainly in the FM7 sample (V = 10 C min-1, T = 300 C, P = 30 min). The greater N/C ratio correlated with a superior amount of nitrogenous functions, presenting by both FM7 and FM4 samples, as determined by 13C NMR spectroscopy with absorptions in 175 ppm (amide) and 55 ppm (N-alkyl).

Pissinati de Rezende, E. I.; Mangrich, A. S.; Batista, M. G. F.; Toledo, J. M. S.; Novotny, E. H.

2012-04-01

320

Analysis of liquid products from biomass via flash pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Flash pyrolysis products from tobacco stalk and yellow pine wood obtained in a pyrolysis apparatus were analyzed. Comparison of pyrolytic products' structural components indicates the origin of each product. Methanol mainly arises from methoxyl groups of uronic acid and from the breakdown of methyl esters and/or ethers from decomposition of pectin-like plant materials. Acetic acid comes from the elimination of acetyl groups originally linked to the xylose unit. The yields of char products from the tobacco stalk and yellow pine wood samples decreased from 33.9% to 23.0% and from 29.2% to 17.0% when final pyrolysis temperature was increased from 675 to 1025 K, respectively. The yields of gaseous products from the tobacco stalk and yellow pine wood samples increased from 25.0% to 40.2% and from 29.7% to 42.5% when final pyrolysis temperature was increased from 675 to 1025 K, respectively. The yields of liquid products from both samples increased with increasing temperature from 675 to 875 K and then decreased. The maximum yields from the tobacco stalk and yellow pine wood samples were 43.0% and 48.7% at 875 K, respectively. The maximum yield of liquid product from the tobacco stalk was 44.5% at 775 K for a 40% Na{sub 2}CO{sub 3} run. Increases and decreases of the yields of liquid products for the tobacco stalk samples were considerably irregular. The maximum yield of liquid product from the yellow pine wood was 44.6% at 775 K for a 50% Na{sub 2}CO{sub 3} run. The maximum yields of acetic acid from yellow pine for nonalkali and alkali runs were 13.85% and 16.58% at 825 K, respectively. The maximum yields of methanol from tea waste for nonalkali and alkali runs were 6.42% and 8.81% at 875 K, respectively. The yields of 1-hydroxy-2-propanone from yellow pine for nonalkali and alkali runs increased from 7.32% to 10.81% and from 7.40% to 12.13% when pyrolysis temperature was increased from 675 to 875 K, respectively. (author)

Demirbas, A.

2002-04-01

 
 
 
 
321

Study on condensation of biomass pyrolysis gas by spray bio-oil droplets  

Energy Technology Data Exchange (ETDEWEB)

This is a study of bio-oil generated by fast pyrolysis; a biomass feedstock is heated to pyrolyze at a rapid rate, the gas pyrolyzed is then condensed rapidly. The interesting result is a potential alternative fuel oil. An analysis was made of the effects of the initial pyrolysis gas temperatures, the initial bio-oil droplets temperatures and diameters, and the flow ratio of the gas and the liquid droplets on the heat and mass transfer between the gas and the liquid droplets. A few criterion equations were achieved with respect to the spray condenser. This paper established the gas-liquid phase equilibrium of an aqueous multi-composition system and the spray condensation model coupling heat and mass transfer. Model calculation and analysis showed that: spray condensation can effectively cool the high-temperature pyrolysis gas quickly; with gas liquid flowing, mass transfer rate reduces; and the relationship of gas and liquid flow ratio can achieve good accuracy.

Xie, Kun; Cheng, Wen-Long [University of Science and Technology of China (China)], email: wlcheng@ustc.edu.cn; Chen, Jing [Anhui Electric Power Design Institute (China); Shi, Wen-Jing [Anhui Heli Co., Ltd (China)

2011-07-01

322

Application of pyrolysis process to remove and recover liquid crystal and films from waste liquid crystal display glass  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer Pyrolysis process can recycle the liquid crystal and films from liquid crystal display glass successfully. Black-Right-Pointing-Pointer The removal of organic parts from the liquid crystal glass reached 87.87 wt%. Black-Right-Pointing-Pointer The mechanism analysis of pyrolysis process explains the whole pyrolysis process perfect. Black-Right-Pointing-Pointer All pyrolysis products can be tilized by a reasonable way. - Abstract: Liquid crystal display (LCD) glass mainly consists of polarizing film, liquid crystal and glass substrate. Removing and recovering the liquid crystal and films from the LCD glass effectively has important significance for recovering the other parts. This study proposed a pyrolysis process to recover the organic parts from LCD glass. Through thermal gravimetric analysis, the pyrolysis temperature of the LCD glass could be chosen at 850 K. The removal rate of organic parts from LCD glass reached 87.87 wt%. Pyrolysis products consisted of 66.82 wt% oils, 21.01 wt% gaseous and 12.13 wt% residues. In addition, the oils contained 46.27 wt% acetic acid and 32.94 wt% triphenyl phosphate. Then, the pyrolysis mechanisms and products sources of the liquid crystal glass have been analyzed based on the information of bonds energy. The pyrolysis mechanism analysis proved that the products mainly consisted of acetic acid, triphenyl phosphate and C, which is consistent to the results of GC-MS analysis. A reasonable way has been put forward to recycle the pyrolysis products: acetic acid and triphenyl phosphate can be collected by distillation, the rest oils and gases can be used as fuel and the remained glass can be used to extract indium and to produce building materials.

Lu, Rixin; Ma, En [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

2012-12-15

323

Application of pyrolysis process to remove and recover liquid crystal and films from waste liquid crystal display glass  

International Nuclear Information System (INIS)

Highlights: ? Pyrolysis process can recycle the liquid crystal and films from liquid crystal display glass successfully. ? The removal of organic parts from the liquid crystal glass reached 87.87 wt%. ? The mechanism analysis of pyrolysis process explains the whole pyrolysis process perfect. ? All pyrolysis products can be tilized by a reasonable way. - Abstract: Liquid crystal display (LCD) glass mainly consists of polarizing film, liquid crystal and glass substrate. Removing and recovering the liquid crystal and films from the LCD glass effectively has important significance for recovering the other parts. This study proposed a pyrolysis process to recover the organic parts from LCD glass. Through thermal gravimetric analysis, the pyrolysis temperature of the LCD glass could be chosen at 850 K. The removal rate of organic parts from LCD glass reached 87.87 wt%. Pyrolysis products consisted of 66.82 wt% oils, 21.01 wt% gaseous and 12.13 wt% residues. In addition, the oils contained 46.27 wt% acetic acid and 32.94 wt% triphenyl phosphate. Then, the pyrolysis mechanisms and products sources of the liquid crystal glass have been analyzed based on the information of bonds energy. The pyrolysis mechanism analysis proved that the products mainly consisted of acetic acid, triphenyl phosphate and C, which is consistent to the results of GCMS analysis. A reasonable way has been put forward to recycle the pyrolysis products: acetic acid and triphenyl phosphate can bid and triphenyl phosphate can be collected by distillation, the rest oils and gases can be used as fuel and the remained glass can be used to extract indium and to produce building materials.

324

Characterization of products obtained from pyrolysis and steam gasification of wood waste, RDF, and RPF.  

Science.gov (United States)

Pyrolysis and steam gasification of woody biomass chip (WBC) obtained from construction and demolition wastes, refuse-derived fuel (RDF), and refuse paper and plastic fuel (RPF) were performed at various temperatures using a lab-scale instrument. The gas, liquid, and solid products were examined to determine their generation amounts, properties, and the carbon balance between raw material and products. The amount of product gas and its hydrogen concentration showed a considerable difference depending on pyrolysis and steam gasification at higher temperature. The reaction of steam and solid product, char, contributed to an increase in gas amount and hydrogen concentration. The amount of liquid products generated greatly depended on temperature rather than pyrolysis or steam gasification. The compositions of liquid product varied relying on raw materials used at 500C but the polycyclic aromatic hydrocarbons became the major compounds at 900C irrespective of the raw materials used. Almost fixed carbon (FC) of raw materials remained as solid products under pyrolysis condition whereas FC started to decompose at 700C under steam gasification condition. For WBC, both char utilization by pyrolysis at low temperature (500C) and syngas recovery by steam gasification at higher temperature (900C) might be practical options. From the results of carbon balance of RDF and RPF, it was confirmed that the carbon conversion to liquid products conspicuously increased as the amount of plastic increased in the raw material. To recover feedstock from RPF, pyrolysis for oil recovery at low temperature (500C) might be one of viable options. Steam gasification at 900C could be an option but the method of tar reforming (e.g. catalyst utilization) should be considered. PMID:24246576

Hwang, In-Hee; Kobayashi, Jun; Kawamoto, Katsuya

2014-02-01

325

High-speed pyrolysis with circulating heat carriers; Schnell-Pyrolyse mit zirkulierenden Waermetraegern  

Energy Technology Data Exchange (ETDEWEB)

Yields and product compositions of pyrolysis reactions depend on the mode of heat supply, the temperature level, and the time of residue at reaction temperature. Using hot circulating granular materials mixed with solid or liquid materials (e.g. biogenic or hydrocarbon-rich residues and waste materials or refinery residues), the following important processes can be investigated: Separation of pyrolysis reaction and heat supply - accurate, optimal temperature levels for pyrolysis, e.g. between 5000 and 850 degrees centigrade - undiluted, unmixed pyrolysis gas - short times of residue of the pyrolysis gas for suppression of secondary reactions. (orig.) [Deutsch] Ausbeuten und Produktzusammensetzung von Pyrolyse-Reaktionen werden weitestgehend durch die Art und Weise der Waermezufuhr, das Temperaturniveau und die Verweilzeit bei Reaktionstemperatur bestimmt. Mit Hilfe des Prinzips heisser, umlaufender, koerniger Waermetraeger in Vermischung - fuer die Pyrolyse-Reaktion - mit festen oder fluessigen Einsatzstoffen (z.B. biogene oder kohlenwasserstoffreiche Rest-/Abfallstoffe, Raffinerie-Rueckstaende) lassen sich folgende wichtige, haeufig gewuenschte Vorgaenge realisieren: - Trennung von Pyrolyse-Reaktion und Waermeversorgung - Temperaturgenaue Pyrolyse-Reaktion auf gewuenschtem, optimalem Niveau waehlbar zwischen z.B. 5000 C und 850 C - Erhalt eines unverduennten, unvermischten Pyrolysegases - Kurze Verweilzeiten des Pyrolysegases zur Unterdrueckung von Sekundaerreaktionen. (orig.)

Schmalfeld, J.; Albrecht, J.; Solmaz, S.; Zentner, U. [Lurgi Energie und Umwelt GmbH, Frankfurt am Main (Germany)

1998-09-01

326

Photoluminescence of spray pyrolysis deposited ZnO nanorods  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Photoluminescence of highly structured ZnO layers comprising well-shaped hexagonal rods is presented. The ZnO rods (length 500-1,000 nm, diameter 100-300 nm) were grown in air onto a preheated soda-lime glass (SGL) or ITO/SGL substrate by low-cost chemical spray pyrolysis method using zinc chloride precursor solutions and growth temperatures in the range of 450-550C. We report the effect of the variation in deposition parameters (substrate type, growth temperature, sp...

Mikli Valdek; Rber Erki, K.; Raadik Taavi; Dedova Tatjana; Ri, Krustok J.; Mere Arvo; Krunks Malle

2011-01-01

327

Material challenges in ethylene pyrolysis furnace heater service  

Energy Technology Data Exchange (ETDEWEB)

Operating temperatures of pyrolysis furnaces are sometimes in excess of 2000/sup 0/F (1100/sup 0/C). These temperatures are very detrimental to the life of the typical HK-40 furnace tubes which normally have a three to five year life in the hot section of these furnaces. Short life is attributed to rapid carburization of ID surfaces which subjects tubes to higher than normal stresses and results in creep cracking of furnace tubes. As an aid to understanding the materials problems the ethylene process will be presented, along with data on the carburization of furnace tubes.

Ibarra, S.

1980-02-01

328

Synthesis of nanosized zirconium carbide by laser pyrolysis route  

International Nuclear Information System (INIS)

Nanosized zirconium carbide was obtained by carburization of tetragonal zirconia/free carbon nanocomposites synthesized by laser pyrolysis technique using zirconium butoxide as precursor and ethylene as sensitizer gas. To achieve the carboreduction, the powder had to be annealed at high temperature under Ar atmosphere to reduce the oxygen and form zirconium carbide (ZrC). Different temperatures were investigated for the heat treatment to obtain the complete carburization while keeping the size as low as possible. The final ZrC grain size was as low as 35 nm. Powders were characterized using X-ray diffraction, thermogravimetric analysis and transmission electron microscopy.

329

Pyrolysis of asphalt ridge tar sand  

Energy Technology Data Exchange (ETDEWEB)

Isothermal and nonisothermal pyrolysis experiments have been conducted on Asphalt Ridge tar sand. Oil produced from the isothermal experiments has a molecular weight of approximately 250 and has a hydrogen to carbon ratio between 1.7 and 1.9. Product oil composition varies slightly with reaction time. Results of thin layer chromatographic separation of the residual bitumen show that the concentrations of saturates and aromatics in this bitumen decrease rapidly with increasing reaction time, while the concentrations of aromatics and polars in this bitumen increase. Polars and polynuclear aromatics are the dominant species in this bitumen. Nonisothermal data have been analyzed using a distributed activation energy technique. These tests show a distinct bimodal weight loss curve. The low temperature weight loss peak has a maximum about 275/sup 0/C (527/sup 0/F) and a first order apparent activation energy below 10 kcal/mol. The high temperature peak has a maximum above 400/sup 0/C (752/sup 0/F) and an apparent activation energy of about 60 kcal/mol. 12 refs., 11 figs., 8 tabs.

Turner, T.F.; Nickerson, L.G.

1986-08-01

330

Kinetic Model Development for Lignin Pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Lignin pyrolysis poses a significant barrier to the formation of liquid fuel products from biomass. Lignin pyrolyzes at higher temperatures than other biomass components (e.g. cellulose and hemi-cellulose) and tends to form radicals species that lead to cross-linking and ultimately char formation. A first step in the advancement of biomass-to-fuel technology is to discover the underlying mechanisms that lead to the breakdown of lignin at lower temperatures into more stable and usable products. We have investigated the thermochemistry of the various inter-linkage units found in lignin (B-O4, a-O4, B-B, B-O5, etc) using electronic structure calculations at the M06-2x/6-311++G(d,p) on a series of dimer model compounds. In addition to bond homolysis reactions, a variety of concerted elimination pathways are under investigation that tend to produce closed-shell stable products. Such a bottom-up approach could aid in the targeted development of catalysts that produce more desirable products under less severe reactor conditions.

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

2012-01-01

331

Comparison on biomaker of coals and materials from hydrous pyrolysis of living plants and peat  

Energy Technology Data Exchange (ETDEWEB)

Biomaker`s changes through all coalification stages were examined by the comparison with biomaker of coals and materials which were produced from hydrous pyrolysis of living plants and peat. A series of hydrous pyrolysis were conducted at several constant temperatures from 200 C to 400 C. From the result of biomaker analysis, the index ratios of hopane and sterane epimerizations, which are well known as the maturity index, increased at vitrinite reflectance (Ro) values from 0.5 to 0.8. But those from products of hydrous pyrolyis were not progressed among whole temperatures. The relationship between biomaker index ratios and Ro has much difference from coals and hydrous pyrolysates. (orig.)

Suzuki, Yuichiro [Geological Survey of Japan, Ibaraki (Japan); Sugimoto, Yoshikazu [National Inst. of Materials and Chemical Research, Ibaraki (Japan); Okada, Kiyohumi [Coal Mining Research Centre, Kasukabe (Japan)

1997-12-31

332

TG-FTIR characterization of pyrolysis of waste mixtures of paint and tar slag.  

Science.gov (United States)

Safe disposal of hazardous waste is becoming generally more important as industrial production increases. The pyrolysis characteristics and gas evolution of mixtures of several wastes are discussed in this paper. Experiments are described for various heating rates, particle sizes and final temperatures using thermogravimetric analysis (TGA) and a Fourier transform infrared spectrometer. The results indicate that there are three stages in the pyrolysis process. The composition of evolved gas includes carbon monoxide, carbon dioxide, ammonia, methane, nitric oxide, hydrocyanic acid and a number of other light alkanes. Gas evolution temperatures and gas generation rates were significantly influenced by the factors identified. PMID:19926219

Tao, Ling; Zhao, Guang-Bo; Qian, Juan; Qin, Yu-kun

2010-03-15

333

Production of sugar and sugar derivatives by pyrolysis of biomass  

Energy Technology Data Exchange (ETDEWEB)

Thermochemical conversion of biomass to sugar and sugar derivatives is hindered by the inhomogeneity of the substrate and the low specificity of the pyrolytic reactions. Recent analysis and investigation of these reactions have shown that they could be controlled and catalyzed to minimize the side reactions and increase the yield of individual compounds. These compounds include levoglucosan which could be obtained in high yields within the temperature range of 350-400/sup 0/C when the substrate has undergone previous acid treatment or a trace amount of acid is present. This phenomenon has been used for production of sugars from softwood and hardwood based on prehydrolysis and subsequent pyrolysis to a tar that could be posthydrolyzed to sugars. Acid-catalyzed pyrolysis of cellulosic materials, particularly waste paper, gives a pyrolyzate containing mainly levoglucosenone which has proved to be a highly reactive compound for production of a variety of carbohydrate derivatives. Pyrolysis of carbohydrates also provides several other furan and pyran derivatives that could be used as synthetic intermediates. 28 references, 22 figures, 11 tables.

Shafizadeh, F.

1983-01-01

334

Pyrolysis of petroleum fractions on an indium oxide catalyst  

International Nuclear Information System (INIS)

Results are presented for the pyrolysis of individual hydrocarbons (hexane and cyclohexane), a mixture of n-paraffins boiling in the 100 to 3000 range, and straight-run gasoline fractions with indium oxide as a catalyst. It was found that optimum dilution of the petroleum fraction with steam occurred at a molar ratio of 1:1. The presence of the indium catalyst was found to increase the yield of low molecular weight olefins under the selected experimental conditions by about 20% when compared with the pyrolysis without an active component catalyst. Kinetic studies of the catalytic reaction indicated that under conditions of pyrolysis, indium oxide takes part in a redox type reaction; also, oxidation which requires the higher temperature is the limiting stage of redox conversions. X-ray studies confirmed the possibility of redox transformation of indium oxide under pyrolytic conditions and the consequent variations in catalytic behavior. Further, an isotope tracer method was used to study the reaction mechanism in the interaction of RH type hydrocarbons and water

335

Evaporation of biomass pyrolysis oil as single droplets  

Energy Technology Data Exchange (ETDEWEB)

Biomass pyrolysis oils are liquid fuels produced by the pyrolysis of wood wastes. This paper described the complex evaporation and combustion behaviour of these fuels. Experiments were performed on the evaporation of pyrolysis oil droplets at high temperatures. The study addressed the issues of polymerization, bubbling and the nature of liquid phase processes. The suspended droplet technique was used in which droplets of 1.4 to 1.7 mm in diameter were placed on the end of a quartz fibre and a preheated electric furnace moved to rapidly enclose the droplet and begin evaporation. A video camera and optical system recorded droplet behaviour, and droplet diameters were measured. The fuel was assumed to consist of four chemical groups, notably aldehydes/ketones, carboxylic acids; lignin; and water. The composition of each of these groups was described by a gamma distribution function. It was shown that bubbling began at the end of initial heating period, indicating that vapour bubbles form by internal vaporization of the lighter inner core. It was concluded that further research is needed to explore the effects of non-uniform concentrations in the droplet in the pre-bubbling period on the initiation of bubbling. 9 refs., 1 tab., 8 figs.

Sari, A.; Hallett, W.L.H. [Ottawa Univ., ON (Canada). Dept. of Mechanical Engineering

2006-07-01

336

The Evritania (Greece) demonstration plant of biomass pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

This paper is focused on describing the Evritania demonstration plant for pyrolysis of forestry biomass. This plant was constructed in the village of Voulpi, district of Evritania, in central Greece, in 1995, with a threefold purpose; development of know-how, forest fire prevention and rural development. The products are charcoal and bio-oil. The plant capacity is 1200-1450 kg/h of wet biomass and the pyrolysis temperature is approx. 400 deg C. The raw material used is Arbutus unedo, which is an evergreen broad-leaf tree which covers the area. Other agricultural waste could also be used, such as olive pits and cuttings, almond shells and cotton kernels. The paper includes the conceptual process flow sheet, the changes and improvements made during the trial phase, data from the start-up phase, and product characteristics. Comparison of the process with the Alten process is presented. Additionally, comparisons are made of product characteristics with those from other pyrolysis processes. In general, the results obtained are encouraging even though several improvements of the pilot plant are required. (author)

Zabaniotou, A.A.; Karabela, A.J. [Aristotle University of Thessaloniki (Greece). Dept. of Chemical Engineering and Chemical Process Engineering Research Institute

1999-06-01

337

Scaling heat and mass flow through porous media during pyrolysis  

Science.gov (United States)

The modelling of heat and mass flow through porous media in the presence of pyrolysis is complex because various physical and chemical phenomena need to be represented. In addition to the transport of heat by conduction and convection, and the change of properties with varying pressure and temperature, these processes involve transport of mass by convection, evaporation, condensation and pyrolysis chemical reactions. Examples of such processes include pyrolysis of wood, thermal decomposition of polymer composite and in situ upgrading of heavy oil and oil shale. The behaviours of these systems are difficult to predict as relatively small changes in the material composition can significantly change the thermophysical properties. Scaling reduces the number of parameters in the problem statement and quantifies the relative importance of the various dimensional parameters such as permeability, thermal conduction and reaction constants. This paper uses inspectional analysis to determine the minimum number of dimensionless scaling groups that describe the decomposition of a solid porous material into a gas in one dimension. Experimental design is then used to rank these scaling groups in terms of their importance in describing the outcome of two example processes: the thermal decomposition of heat shields formed from polymer composites and the in situ upgrading of heavy oils and oil shales. A sensitivity analysis is used to divide these groups into three sets (primary, secondary and insignificant), thus identifying the combinations of solid and fluid properties that have the most impact on the performance of the different processes.

Maes, Julien; Muggeridge, Ann H.; Jackson, Matthew D.; Quintard, Michel; Lapene, Alexandre

2014-07-01

338

Co-pyrolysis characteristics and kinetics of coal and plastic blends  

International Nuclear Information System (INIS)

Co-pyrolysis behaviors of different plastics (high density polyethylene, low density polyethylene and polypropylene), low volatile coal (LVC) and their mixtures were investigated by TGA. Experiments were conducted under N2 atmosphere at heating rate of 20 deg. C/min from room temperature to 750 deg. C. The results showed that the thermal degradation temperature range of plastic was 438-521 deg. C, while that of coal (LVC) was 174-710 deg. C. Plastics showed similar pyrolysis characteristics due to similar chemical bonds in their molecular structures. The overlapping degradation temperature interval between coal and plastic provide an opportunity for free radicals from coal pyrolysis to participate in the reactions of plastic decomposition. The difference of weight loss percent (?W) between experimental and theoretical ones, calculated as an algebraic sum of those from each separated component, ?W is 2.0-2.7% at the pyrolysis temperature higher than 530 deg. C, which indicates that the synergistic effect during pyrolysis occurs mainly in the high temperature region. The kinetic studies were performed according to Coats and Redfern method for first-order reaction. It was found that for plastics (HDPE, LDPE and PP), the pyrolysis process can be described by one first-order reaction. However, for LVC and LVC/plastic blends, this process can be described by three and four consecutive first-order reactions, respectively. The estimated kinetic parameters viz., aThe estimated kinetic parameters viz., activation energies and pre-exponential factors for coal, plastic and their blends, were found to be in the range of 35.7-572.8 kJ/mol and 27-1.7 x 1038 min-1, respectively

339

Diastereoselective dihydroxylation and regioselective deoxygenation of dihydropyranones: a novel protocol for the stereoselective synthesis of C1-C8 and C15-C21 subunits of (+)-discodermolide.  

Science.gov (United States)

Diastereoselective dihydroxylation of dihydropyranones and subsequent regioselective alpha-deoxygenation provides 1,3-trans-beta-hydroxy-delta-lactones stereoselectively. This protocol has been applied for the synthesis of C(1)-C(8) and C(15)-C(21) subunits of (+)-discodermolide. PMID:15357588

Ramachandran, P Veeraraghavan; Prabhudas, Bodhuri; Chandra, J Subash; Reddy, M Venkat Ram

2004-09-17

340

Synthesis of Ruthenium Carbonyl Complexes with Phosphine or Substituted Cp Ligands, and Their Activity in the Catalytic Deoxygenation of 1,2-Propanediol  

International Nuclear Information System (INIS)

A ruthenium hydride with a bulky tetra-substituted Cp ligand, (CpiPr4)Ru(CO)2H (CpiPr4 = C5(i-C3H7)4H) was prepared from the reaction of Ru3(CO)12 with 1,2,3,4-tetraisopropylcyclopentadiene. The molecular structure of (CpiPr4)Ru(CO)2H was determined by X-ray crystallography. The ruthenium hydride complex (C5Bz5)Ru(CO)2H (Bz = CH2Ph) was similarly prepared. The Ru-Ru bonded dimer, ((1,2,3-trimethylindenyl)Ru(CO)2)2, was produced from the reaction of 1,2,3-trimethylindene with Ru3(CO)12, and protonation of this dimer with HOTf gives {((1,2,3-trimethylindenyl)Ru(CO)2)2-(?-H)}+OTf-. A series of ruthenium hydride complexes CpRu(CO)(L)H (L = P(OPh)3, PCy3, PMe3, P(p-C6H4F)3) were prepared by reaction of Cp(CO)2RuH with added L. Protonation of (CpiPr4)Ru(CO)2H, Cp*Ru(CO)2H, or CpRu(CO)(P-(OPh)3)H by HOTf at -80 C led to equilibria with the cationic dihydrogen complexes, but H2 was released at higher temperatures. Protonation of CpRu(P(OPh)3)2H with HOTf gave an observable dihydrogen complex, {CpRu(P-(OPh)3)2(?2-H2)}+OTf- that was converted at -20 C to the dihydride complex {CpRu(P(OPh)3)2(H)2}+OTf-. These Ru complexes serve as catalyst precursors for the catalytic deoxygenation of 1,2-propanediol to give n-propanol. The catalytic reactions were carried out in sulfolane solvent with added HOTf under H2 (750 psi) at 110 C.

 
 
 
 
341

Thermal/Pyrolysis Gas Flow Analysis of Carbon Phenolic Material  

Science.gov (United States)

Provided in this study are predicted in-depth temperature and pyrolysis gas pressure distributions for carbon phenolic materials that are externally heated with a laser source. Governing equations, numerical techniques and comparisons to measured temperature data are also presented. Surface thermochemical conditions were determined using the Aerotherm Chemical Equilibrium (ACE) program. Surface heating simulation used facility calibrated radiative and convective flux levels. Temperatures and pyrolysis gas pressures are predicted using an upgraded form of the SINDA/CMA program that was developed by NASA during the Solid Propulsion Integrity Program (SPIP). Multispecie mass balance, tracking of condensable vapors, high heat rate kinetics, real gas compressibility and reduced mixture viscosity's have been added to the algorithm. In general, surface and in-depth temperature comparisons are very good. Specie partial pressures calculations show that a saturated water-vapor mixture is the main contributor to peak in-depth total pressure. Further, for most of the cases studied, the water-vapor mixture is driven near the critical point and is believed to significantly increase the local heat capacity of the composite material. This phenomenon if not accounted for in analysis models may lead to an over prediction in temperature response in charring regions of the material.

Clayton, J. Louie

2001-01-01

342

Pyrolysis of rapeseed in a free fall reactor for production of bio-oil  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis experiments of rapeseed (Brassica napus L.) were performed in a free fall reactor at atmospheric pressure under nitrogen atmosphere. The effects of final pyrolysis temperature, particle size and sweep gas flow rate on the yields of products were investigated. The temperature of pyrolysis, particle size and sweep gas flow rate were varied in the ranges of 400 700{sup o}C, -0.224 to 1.8 mm and 50-400 cm{sup 3} min{sup -1}, respectively. 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 ({sup 1}H NMR, IR, column chromatography and GC/MS). The chemical characterization has shown that the bio-oil obtained from rapeseed could be use as diesel fuel and chemical feeedstock. 23 refs., 5 figs., 8 tabs.

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

2006-09-15

343

Suppressing cross-linking reactions during pyrolysis of lignite pretreated by pyridine  

Energy Technology Data Exchange (ETDEWEB)

A Chinese lignite Yitai (YT) was pretreated by pyridine vapor and pyridine solvent. The effects of the treatments on the pyrolysis behavior of the pretreated coals were studied by thermogravimetric mass spectrometry (TG-MS). The results showed that both treatments could suppress the cross-linking reactions (CLRs) during pyrolysis of the treated coal, but the suppressing temperature range and mechanism were different. Some inherent hydrogen bonds (HBs) in the coal were broken by pyridine vapor treatment and new stronger N OH HBs were formed. Thus, low temperature CLRs (below 400{sup o}C) that were related to the hydrogen-bonded COOH COOH and COOH OH were suppressed. However, pyridine solvent pretreatment influenced the pyrolysis behavior by reducing the association interactions between the low molecular weight compounds and macromolecular network, thus relaxing the three-dimensional network of coal and enhancing the transmission efficiency of hydrogen in coal. 22 refs., 3 figs., 1 tab.

Zhi-qing Wang; Zong-qing Bai; Wen Li; Bao-qing Li; Hao-kan Chen [Chinese Academy of Sciences, Taiyuan (China). State Key Laboratory of Coal Conversion

2008-12-15

344

Analytical pyrolysis experiments of Titan aerosol analogues in preparation for the Cassini Huygens mission.  

Science.gov (United States)

Comparative pyrolysis mass spectrometric data of Titan aerosol analogues, called "tholins", are presented. The Titan tholins were produced in the laboratory at Cornell by irradiation of simulated Titan atmospheres with high energy electrons in plasma discharge. Mass-spectrometry measurements were performed at FOM of the solid phase of various tholins by Curie-point pyrolysis Gas-Chromatography/Mass-Spectrometry (GCMS) and by temperature resolved in source Pyrolysis Mass-Spectrometry to reveal the composition and evolution temperature of the dissociation products. The results presented here are used to further define the ACP (Aerosol Collector Pyrolyser)-GCMS experiment and provide a basis for modelling of aerosol composition on Titan and for the interpretation of Titan atmosphere data from the Huygens probe in the future. PMID:11539247

Ehrenfreund, P; Boon, J J; Commandeur, J; Sagan, C; Thompson, W R; Khare, B

1995-03-01

345

Hazardous air pollutant formation from pyrolysis of typical Chinese casting materials.  

Science.gov (United States)

Analytical pyrolysis was conducted to evaluate the major hazardous air pollutant (HAP) emissions from pyrolysis of bituminous coal and a furan binder, which are the two most commonly used casting materials for making green sand and furan no-bake molds in Chinese foundries. These two materials were flash pyrolyzed in a Curie-point pyrolyzer at 920 C and slowly pyrolyzed in a thermogravimetric analyzer (TGA) from ambient temperature to 1000 C with a heating rate of 30 C/min. The emissions from Curie-point and TGA pyrolysis were analyzed with gas chromatography-mass spectrometer/flame ionization detector. Thirteen HAP species were identified and quantified in the pyrolysis emissions of the two materials. The prominent HAP emissions were cresols, benzene, toluene, phenol, and naphthalene for the bituminous coal, whereas they were m,p,o-xylenes for the furan binder. Xylenesulfonic acid, the acidic catalyst in furan binder, was found to be the major source of xylene emissions. Thermogravimetry-mass spectrometer monitored the evolution of HAP emissions during TGA pyrolysis. For both of the casting materials, most of the emissions were released in the temperature range of 350-700 C. PMID:21714543

Wang, Yujue; Zhang, Ying; Su, Lu; Li, Xiangyu; Duan, Lei; Wang, Chengwen; Huang, Tianyou

2011-08-01

346

Effect of cellulose, lignin, alkali and alkaline earth metallic species on biomass pyrolysis and gasification  

Energy Technology Data Exchange (ETDEWEB)

Fundamental pyrolysis/gasification characteristics of natural biomass and acid-washed biomass without alkali and alkaline earth metals (AAEM) were investigated by a thermogravimetric analyzer (TGA) and a fixed-bed reactor. In these experiments, six types of biomass were used and the contents of cellulose, lignin and AAEM species in the biomass were measured. It was observed that the characteristic of biomass pyrolysis and gasification was dependent on its components and AAEM species on the basis of TGA experiments. During biomass pyrolysis, the tar and gas yields increased with the growth of cellulose content, but the char yield decreased. There were two reactions indicating two major decomposition mechanisms. The first stage of decomposition showed rapid mass decrease due to the volatilization of cellulose, while the second stage became slow attributed to the lignin decomposition. The higher the cellulose content, the faster the pyrolysis rate. In contrast, the pyrolysis rate of biomass with higher lignin content became slower. In addition, the rises of cellulose content elevated the peak temperature of gasification and prolonged the gasification time. Meanwhile, the effect of AAEM species on gasification behavior was studied by comparing unwashed and acid-washed biomass. AAEM species increased the peak gasification value, whereas decreased initial gasification temperature. It revealed that the activity of biomass gasification was attributed to the interaction between AAEM-cellulose/lignin. (author)

Lv, Dangzhen; Xu, Minghou; Liu, Xiaowei; Zhan, Zhonghua; Li, Zhiyuan; Yao, Hong [State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074 (China)

2010-08-15

347

Recycling of organic materials and solder from waste printed circuit boards by vacuum pyrolysis-centrifugation coupling technology.  

Science.gov (United States)

Here, we focused on the recycling of waste printed circuit boards (WPCBs) using vacuum pyrolysis-centrifugation coupling technology (VPCT) aiming to obtain valuable feedstock and resolve environmental pollution. The two types of WPCBs were pyrolysed at 600C for 30 min under vacuum condition. During the pyrolysis process, the solder of WPCBs was separated and recovered when the temperature range was 400-600C, and the rotating drum was rotated at 1000 rpm for 10 min. The type-A of WPCBs pyrolysed to form an average of 67.91 wt.% residue, 27.84 wt.% oil, and 4.25 wt.% gas; and pyrolysis of the type-B of WPCBs led to an average mass balance of 72.22 wt.% residue, 21.57 wt.% oil, and 6.21 wt.% gas. The GC-MS and FT-IR analyses showed that the two pyrolysis oils consisted mainly of phenols and substituted phenols. The pyrolysis oil can be used for fuel or chemical feedstock for further processing. The recovered solder can be recycled directly and it can also be a good resource of lead and tin for refining. The pyrolysis residues contained various metals, glass fibers and other inorganic materials, which could be recovered after further treatment. The pyrolysis gases consisted mainly of CO, CO(2), CH(4), and H(2), which could be collected and recycled. PMID:21840196

Zhou, Yihui; Wu, WenBiao; Qiu, Keqiang

2011-12-01

348

An economic analysis of mobile pyrolysis for northern New Mexico forests.  

Energy Technology Data Exchange (ETDEWEB)

In the interest of providing an economically sensible use for the copious small-diameter wood in Northern New Mexico, an economic study is performed focused on mobile pyrolysis. Mobile pyrolysis was selected for the study because transportation costs limit the viability of a dedicated pyrolysis plant, and the relative simplicity of pyrolysis compared to other technology solutions lends itself to mobile reactor design. A bench-scale pyrolysis system was used to study the wood pyrolysis process and to obtain performance data that was otherwise unavailable under conditions theorized to be optimal given the regional problem. Pyrolysis can convert wood to three main products: fixed gases, liquid pyrolysis oil and char. The fixed gases are useful as low-quality fuel, and may have sufficient chemical energy to power a mobile system, eliminating the need for an external power source. The majority of the energy content of the pyrolysis gas is associated with carbon monoxide, followed by light hydrocarbons. The liquids are well characterized in the historical literature, and have slightly lower heating values comparable to the feedstock. They consist of water and a mix of hundreds of hydrocarbons, and are acidic. They are also unstable, increasing in viscosity with time stored. Up to 60% of the biomass in bench-scale testing was converted to liquids. Lower ({approx}550 C) furnace temperatures are preferred because of the decreased propensity for deposits and the high liquid yields. A mobile pyrolysis system would be designed with low maintenance requirements, should be able to access wilderness areas, and should not require more than one or two people to operate the system. The techno-economic analysis assesses fixed and variable costs. It suggests that the economy of scale is an important factor, as higher throughput directly leads to improved system economic viability. Labor and capital equipment are the driving factors in the viability of the system. The break-even selling price for the baseline assumption is about $11/GJ, however it may be possible to reduce this value by 20-30% depending on other factors evaluated in the non-baseline scenarios. Assuming a value for the char co-product improves the analysis. Significantly lower break-even costs are possible in an international setting, as labor is the dominant production cost.

Brady, Patrick D.; Brown, Alexander L.; Mowry, Curtis Dale; Borek, Theodore Thaddeus, III

2011-12-01

349

Pyrolysis of D-Glucose to Acrolein  

Science.gov (United States)

Despite of its great importance, the detailed molecular mechanism for carbohydrate pyrolysis remains poorly understood. We perform a density functional study with a newly developed XYG3 functional on the processes for D-glucose pyrolysis to acrolein. The most feasible reaction pathway starts from an isomerization from D-glucose to D-fructose, which then undergoes a cyclic Grob fragmentation, followed by a concerted electrocyclic dehydration to yield acrolein. This mechanism can account for the known experimental results.

Shen, Chong; Zhang, Igor Ying; Fu, Gang; Xu, Xin

2011-06-01

350

Influence of reaction conditions on fast pyrolysis of macroalge  

International Nuclear Information System (INIS)

Full text: The importance of renewable energy sources has increased rapidly due to the high international crude oil prices and environmental concerns over fossil fuel use. Recently, there has been a growing interest in aquatic biomass, especially marine macro algae, and a number of studies have been initiated to evaluate its potential for bio-energy. This paper reports a fast pyrolysis of macro algae under different reaction conditions such as pyrolysis temperature, particle size and sample quantity. Various macro algae such as Undaria pinnatifida, Laminaria japonica and Porphyra tenera were fast pyro lysed at temperatures between 300-600 degree Celsius in a batch reactor and the main product of bio-oil was obtained. The optimal reaction temperature for the production of bio-oil was 500 degree Celsius. At this temperature, the maximum bio-oil yields were 40.4 wt % ( by Undaria pinnatifida), 37.6 wt % (by Laminaria japonica) and 47.4 wt % (by Porphyra tenera), respectively. In particular, after pre-treatment with 2.0M HCl solution, the product yield of bio-oil was increased in macro algae, Undaria pinnatifida. The pyroylsis gases were analyzed by using GC-TCD and GC-FID and qualitative analyses of bio-oil were performed using GC-MS. The maximum yield of bio-oil, Undaria pinnatifida, Laminaria japonica and Porphyra tenera, was obtained at 500 degree Celsius (40.4 wt %, 37.6 wt % and 47.4 wt %, respectively). (author)

351

Influence of impregnation method on metal retention of CCB-treated wood in slow pyrolysis process  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer CCB-treated wood using dipping method contains more metals (Cu, Cr, B) than CCB-treated wood using pressure method. Black-Right-Pointing-Pointer Cu, Cr, B contained in CCB-treated wood catalyze pyrolysis reaction of wood. Black-Right-Pointing-Pointer This phenomenon is more pronounced for dipping CCB-treated wood than for pressure treated wood. Black-Right-Pointing-Pointer The charcoal obtained by pyrolysis of CCB-treated wood using both methods is higher than the value obtained from untreated wood. Black-Right-Pointing-Pointer More than 45% of Cu, Cr and B are captured in charcoal of CCB-treated wood. - Abstract: In the present work, the effects of copper, chromium and boron on the pyrolysis of wood and their distribution in the pyrolysis products were investigated. For this, the wood has been impregnated with chromium-copper-boron (CCB). In addition, to describe the effects of impregnation method, vacuum-pressure and dipping methods were also conducted. Thermogravimetric analysis (TGA) results show that an increase in the final residue and decrease in degradation temperature on both methods of treated wood compared to untreated wood. Then, slow pyrolysis experiments were carried out in a laboratory reactor. The mass balance of pyrolysis products is confirmed by TGA. Furthermore, the concentration of metals in the final residue is measured by inductively coupled plasma mass spectroscopy (ICP-MS). The results show that the final residue contains more than 45% of the initial amount of metal present in the treated wood. The phenomenon is more pronounced with vacuum-pressure treated wood. The heating values of pyrolysis products were analyzed. The heating value of charcoal obtained from treated and untreated wood is approximately same. But the heating value of tar from untreated wood is higher than the heating value of the tar from treated wood.

Kinata, Silao Esperance, E-mail: Esperance.Kinata@mines-nantes.fr [GEPEA, UMR 6144, Departement Systemes Energetiques et Environnement, Ecole des Mines de Nantes, La chantrerie, 04 rue Alfred Kastler B.P. 20722 F-44307 Nantes Cedex 3 (France); Loubar, Khaled [GEPEA, UMR 6144, Departement Systemes Energetiques et Environnement, Ecole des Mines de Nantes, La chantrerie, 04 rue Alfred Kastler B.P. 20722 F-44307 Nantes Cedex 3 (France); Bouslamti, Amine; Belloncle, Christophe [LUNAM Universite, Ecole Superieure du Bois, rue Christian PAUC, B.P. 10605, 44306 Nantes Cedex (France); Tazerout, Mohand [GEPEA, UMR 6144, Departement Systemes Energetiques et Environnement, Ecole des Mines de Nantes, La chantrerie, 04 rue Alfred Kastler B.P. 20722 F-44307 Nantes Cedex 3 (France)

2012-09-30

352

Fast pyrolysis of microalgae in a falling solids reactor: Effects of process variables and zeolite catalysts  

International Nuclear Information System (INIS)

Non-catalytic and catalytic pyrolysis of microalgae were carried out to generate an organic liquid fuel precursor. The impacts of several process variables on the fast pyrolysis in a falling solids reactor are reported, including temperature, particle size, flow rate, and atmosphere (N2, H2O and CO2). Experiments were carried out with duckweed as the biomass to provide some comparison. The speciated organic phase product data were classified according to the different compound types including hydrocarbons, alcohols, oxygenates, and nitrogenates. In-situ catalytic pyrolysis produced an organic phase with an increased fraction of hydrocarbons and decreased fraction of oxygenates, evidence for carbon removal chemistries such as decarboxylation and decarbonylation. The noncatalytic pyrolysis gave the highest total liquid yield while catalytic pyrolysis resulted in the highest yield of the desired hydrocarbon fraction. A comparison of four exchanged ZSM-5 catalysts (H-, Fe-, Cu-, and Ni-) indicates that the protonated zeolite provided the largest enhancement among the catalysts of the liquid product yield and composition: H-ZSM-5 increased the yield of the hydrocarbon fraction in the organic phase from 21% to 43%, a 100% relative increase, and exhibited the least coking. The effects of biomass weight hourly space velocity, and comparisons between H-ZSM5 powder and monolithic catalysts are also reported. The implications of the findings for the conversion of microalgae to liquid fuels are discussed. -- Graphical abstract: Display Omitted Highlights: ? Pyrolysis of microalgae and duckweed in falling solids reactor. ? Effect of process variables on product yields and compositions determined. ? Catalytic pyrolysis enhances bio-oil composition. ? Shape selective ZSM-5 catalysts enhance hydrocarbon yield.

353

Research on pyrolysis characteristics and kinetics of super fine and conventional pulverized coal  

International Nuclear Information System (INIS)

Based on isothermal thermogravimetric analysis (TGA) and kinetic equations, the optimization toolbox of MATLAB was applied to study the effects of particle size and heating rate on the pyrolysis characteristics and kinetics and to obtain the mechanism function and kinetic parameters of Yuanbaoshan coal at four different particle sizes and heating rates. The pyrolysis characteristics of the samples were analyzed using thermogravimetric (TG) curves and differential thermogravimetric (DTG) curves. The results show that the coal pyrolysis process is strongly affected by heating rate and particle size. As the heating rate increases, the temperature of volatile matter initiation increases, the total volatile matter evolved decreases and the DTG peak shifts toward higher temperature. As the particle size decreases, the temperature of volatile matter initiation of the coal sample decreases and the maximum rate of mass loss increases. In the pyrolysis of coal, the activation energies of the samples were found to increase with growing particle size and decreasing heating rate for both of the devolatilization temperature stages. In the lower temperature stage, the coal samples show a great difference in mechanism function at different particle sizes and heating rates

354

CuS Thin Films Obtained by Spray Pyrolysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents a study concerning the influence of deposition parameters (reagents, electron donors, surfactants, temperature of the substrate, number of consecutive layers, spraying rate) on the quality of CuS thin films achieved by spray pyrolysis on glass substrate, from solutions containing CuCl22H2O, thiourea, electron pair donors and surfactants. As electron pairs donors ammonia and triethanolamine were used and as surfactants C12 - C14 ether-sulphate, sodium lauryl-sulphate and c...

Popescu, Violeta; Nas?cu, Horea Iustin

2004-01-01

355

Test plan for ISV laboratory-pyrolysis testing  

Energy Technology Data Exchange (ETDEWEB)

The objective of the laboratory-pyrolysis studies is to obtain information on the high temperature (< 1200{degree}C) degradation and alteration of organic chemicals and materials similar to those found in the Radioactive Waste Management Complex, Pit 9. This test plan describes experimental procedures, sampling and analysis strategy, sampling procedures, sample control, and document management. It addresses safety issues in the experimental apparatus and procedures, personal training, and hazardous waste disposal. Finally, it describes the data quality objectives using the EPA tiered approach to treatability studies to define where research/scoping tests fit into these studies and the EPA analytical levels required for the tests.

McAtee, R.E.

1991-09-01

356

Modelling solid-convective flash pyrolysis of straw and wood in the Pyrolysis Centrifuge Reactor  

DEFF Research Database (Denmark)

Less than a handful of solid-convective pyrolysis reactors for the production of liquid fuel from biomass have been presented and for only a single reactor a detailed mathematical model has been presented. In this article we present a predictive mathematical model of the pyrolysis process in the Pyrolysis Centrifuge Reactor, a novel solid-convective flash pyrolysis reactor. The model relies on the original concept for ablative pyrolysis of particles being pyrolysed through the formation of an intermediate liquid compound which is further degraded to form liquid organics, char, and gas. To describe the kinetics of the pyrolysis reactions the Broido-Shafizadeh scheme is employed with cellulose parameters for wood and modified parameters for straw to include the catalytic effect of its alkali-containing ash content. The model describes the presented experimental results adequately for engineering purposes for both wood and straw feedstock even though conditions for ablative pyrolysis from a reaction engineering point of view are not satisfied. Accordingly, even though the concept of an ablatively melting particle may constitute a limiting case, it can still be used to model flash pyrolysis provided that the reacting particle continuously shed the formed char layer.

Bech, Niels; Larsen, Morten Boberg

2009-01-01

357

Modelling solid-convective flash pyrolysis of straw and wood in the Pyrolysis Centrifuge Reactor  

International Nuclear Information System (INIS)

Less than a handful of solid-convective pyrolysis reactors for the production of liquid fuel from biomass have been presented and for only a single reactor a detailed mathematical model has been presented. In this article we present a predictive mathematical model of the pyrolysis process in the Pyrolysis Centrifuge Reactor, a novel solid-convective flash pyrolysis reactor. The model relies on the original concept for ablative pyrolysis of particles being pyrolysed through the formation of an intermediate liquid compound which is further degraded to form liquid organics, char, and gas. To describe the kinetics of the pyrolysis reactions the Broido-Shafizadeh scheme is employed with cellulose parameters for wood and modified parameters for straw to include the catalytic effect of its alkali-containing ash content. The model describes the presented experimental results adequately for engineering purposes for both wood and straw feedstock even though conditions for ablative pyrolysis from a reaction engineering point of view are not satisfied. Accordingly, even though the concept of an ablatively melting particle may constitute a limiting case, it can still be used to model flash pyrolysis provided that the reacting particle continuously shed the formed char layer.

358

A new design for a simple and effective pyrolysis nozzle in a supersonic free jet  

Science.gov (United States)

A new design for a pyrolysis nozzle to be used in conjunction with a supersonic free jet is presented. Advantages include its simple construction and inexpensive materials. The difluorocarbene (CF2) radical was chosen as a test molecule, and its (1B1)?X(1A1) electronic transition was examined using laser induced fluorescence spectroscopy. The radical was formed by pyrolysis of C2F4 at 1200 K within the nozzle. The effect of different nozzle designs on the subsequent vibrational and rotational cooling was investigated. Small changes in design and expansion conditions resulted in large changes in ultimate rotational and vibrational temperature.

Cameron, Melanie R.; Kable, Scott H.

1996-01-01

359

Modeling of silane pyrolysis in a continuous flow reactor. Low-Cost Solar Array Project  

Energy Technology Data Exchange (ETDEWEB)

Silane pyrolysis in a continuous flow pyrolyzer is a simple process that is currently being developed for producing solar cell grade silicon. The process involves complex phenomena, however, including thermal decomposition of silane, nucleation and growth of silicon particles, and mass and heat transfer. Modeling the effects of transport phenomena on silane pyrolysis in a continuous flow pyrolyzer is discussed. One- and two-dimensional models are developed to predict velocity, temperature, and concentration profiles in the reactor. The one-dimensional model has been implemented as a computer code.

Praturi, A.; Jain, R.; Hsu, G.C.

1979-04-01

360

Thermal behaviour and kinetics of alga Polysiphonia elongata biomass during pyrolysis.  

Science.gov (United States)

The pyrolysis characteristics and kinetics of Polysiphonia elongata were investigated using a thermogravimetric analyzer. The main decomposition of samples occurred between 225C and 485C at heating rates of 5-40C/min; owing to release of 78-82% of total volatiles. The heating rate effected pyrolysis characteristics such as maximum devolatilization rate and decomposition temperature. However, total volatile matter yield was not significantly affected by heating rate. The activation energy of pyrolysis reaction was calculated by model free Friedman and Kissenger-Akahira-Sunose methods and mean values were 116.23kJ/mol and 126.48kJ/mol, respectively. A variance in the activation energy with the proceeding conversions was observed for the models applied, which shows that the pyrolysis process was composed of multi-step kinetics. The Coats-Redfern method was used to determine pre-exponential factor and reaction order. The obtained parameters were used in simulation of pyrolysis process and results were in a good agreement with experimental data. PMID:25194914

Ceylan, Selim; Topcu, Y?ld?ray; Ceylan, Zeynep

2014-11-01

 
 
 
 
361

Application of Gamma Radiation on Bio-oil Produced from Pyrolysis of Soybean Cake  

International Nuclear Information System (INIS)

Soybean cake residue from soy milk making can be pyrolysed to produce pyrolysis liquid or bio-oil which has potency to be used as liquid fuel. Pyrolysis of soybean cake residue with the application of gamma irradiation was investigated in a batch reactor at 450C for 1.5 hr under nitrogen flow 250 cc/min. Feed of soybean cake residue was exposed to gamma radiation at the doses of 200 to 1,000 kGy before pyrolysing. It was found that pyrolysis liquid yield increased significantly by 12.9 to 19.3 % at the irradiation doses of 400 kGy and higher. The increment was mainly due to the increasing of aqueous phase in the pyrolysis liquid. The heating value of organic phase in the pyrolysis liquid was 7,890 kcal/kg. The organic phase from the unexposed feed was also irradiated at 20-100 kGy. The viscosity of irradiated organic phase was found to increase with the increasing irradiation dose. Irradiated organic phase was distilled at temperatures 200 and 250C. It was found that the first distilled fraction (<200C) corresponding to gasoline fraction increased with the increasing irradiation dose while the second distilled fraction (200-250C) corresponding to kerosene fraction seems to decrease. The composition of organic phase was also determined by GC-MS.

362

Processing of uranium oxide and silicon carbide based fuel using polymer infiltration and pyrolysis  

Science.gov (United States)

Ceramic composite pellets consisting of uranium oxide, UO 2, contained within a silicon carbide matrix, were fabricated using a novel processing technique based on polymer infiltration and pyrolysis (PIP). In this process, particles of depleted uranium oxide, in the form of U 3O 8, were dispersed in liquid allylhydridopolycarbosilane (AHPCS), and subjected to pyrolysis up to 900 C under a continuous flow of ultra high purity argon. The pyrolysis of AHPCS, at these temperatures, produced near-stoichiometric amorphous silicon carbide ( a-SiC). Multiple polymer infiltration and pyrolysis (PIP) cycles were performed to minimize open porosity and densify the silicon carbide matrix. Analytical characterization was conducted to investigate chemical interaction between U 3O 8 and SiC. It was observed that U 3O 8 reacted with AHPCS during the very first pyrolysis cycle, and was converted to UO 2. As a result, final composition of the material consisted of UO 2 particles contained in an a-SiC matrix. The physical and mechanical properties were also quantified. It is shown that this processing scheme promotes uniform distribution of uranium fuel source along with a high ceramic yield of the parent matrix.

Singh, Abhishek K.; Zunjarrao, Suraj C.; Singh, Raman P.

2008-09-01