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1

EPR study of deoxygenated high-temperature superconductors  

International Nuclear Information System (INIS)

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

2

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Zanzi, Rolando

2001-01-01

3

High temperature pyrolysis of vinylacetylene  

Science.gov (United States)

The thermal decomposition of vinylacetylene has been studied behind reflected shock waves in the temperature range 1350-1870 K at total pressures between 1.7 and 7.4 bar. Initial concentrations of the hydrogen in argon ranged between 1 to 300 ppm. The following species were measured: H-atoms by ARAS, C2H2, C4H2 and C4H4 by molecular vuv-absorption. The combination of very low initial concentrations with a sensitive detection technique allowed to perform the experiments under conditions where only very few elementary reaction steps determine the progress of reaction. It was found that C4H4 decomposes simultaneously into different product channels: C4H4?C2H2+C2H2 k1a=3.4?1013 exp(-38820/T) s-1 C4H4+Ar?C4H3+H+Ar k1b=1.1?1020exp(-49990/T) cm3 mol-1 s-1 C4H4?C4H2+H2 k1c=1.3?1015exp(-47670/T) s-1. From variation of the total pressure it has been deduced that reaction pathways R1a and R1c proceed with rates not far from the high-pressure limiting values and that reaction R1b proceeds close to the low-pressure limiting rate constant values.

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

1990-07-01

4

Formate assisted pyrolysis of pine sawdust for in-situ oxygen removal and stabilization of bio-oil.  

Science.gov (United States)

Pine sawdust was pretreated with several calcium compounds and then pyrolyzed in a fluidized bed pyrolysis reactor at 500C. The catalytic action of the calcium compounds varies depending on the anion. Analysis of pyrolysis gas, liquid and char yields and compositions demonstrates that calcium sulfate is inert during pyrolysis while calcium formate, carbonate, hydroxide and oxide show significant deoxygenation activity. Of the salts which showed deoxygenation activity, calcium formate had the highest relative yield. This effect is likely attributable to the activity of calcium formate as a hydrogen donor at the pyrolysis temperature. PMID:25305646

Case, Paige A; Wheeler, M Clayton; DeSisto, William J

2014-12-01

5

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

Science.gov (United States)

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

Qian, Yangyang; Zhang, Jie; Wang, Jie

2014-10-20

6

Pyrolysis and gasification of coal at high temperatures  

Energy Technology Data Exchange (ETDEWEB)

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

Zygourakis, K.

1990-01-01

7

High-temperature pyrolysis mechanisms of coal model compounds  

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-01-01

8

Pyrolysis temperature influences ameliorating effects of biochars on acidic soil.  

Science.gov (United States)

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

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

2014-02-01

9

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

10

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

Science.gov (United States)

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

Zhang, Jie; Liu, Jia; Liu, Rongle

2015-01-01

11

Hardfacing of high temperature alloys for ethylene pyrolysis applications  

Energy Technology Data Exchange (ETDEWEB)

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

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

1994-12-31

12

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

Science.gov (United States)

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

Guan, Jian; Qi, Guoli; Dong, Peng

2014-06-01

13

Effect of pyrolysis temperature and air flow on toxicity of gases from a polycarbonate polymer  

Science.gov (United States)

A polycarbonate polymer was evaluated for toxicity of pyrolysis gases generated at various temperatures without forced air flow and with 1 L/min air flow, using the toxicity screening test method developed at the University of San Francisco. Time to various animal responses decreased with increasing pyrolysis temperature over the range from 500 C to 800 C. There appeared to be no significant toxic effects at 400 C and lower temperatures.

Hilado, C. J.; Brick, V. E.; Brauer, D. P.

1978-01-01

14

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2006-01-01

15

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

International Nuclear Information System (INIS)

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

16

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

Directory of Open Access Journals (Sweden)

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

Renjie Dong

2013-07-01

17

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. ...

Yu Jiao-zhu, Li Lin

2014-01-01

18

Fluctuations between conformational substrates in deoxygenated myoglobin  

International Nuclear Information System (INIS)

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

19

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

20

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

Science.gov (United States)

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

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

2014-12-01

 
 
 
 
21

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

Directory of Open Access Journals (Sweden)

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

Anchan Paethanom

2012-11-01

22

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

23

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

Science.gov (United States)

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

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

2013-04-25

24

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 950C ...

Couhert, Carole

2007-01-01

25

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

26

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.

27

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

28

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

29

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

Science.gov (United States)

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

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

2014-01-01

30

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

DEFF Research Database (Denmark)

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

Trinh, Ngoc Trung; Jensen, Peter Arendt

2013-01-01

31

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.

32

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-10-15

33

Production of hydrogen-rich gas from plant biomass by catalytic pyrolysis at low temperature  

Energy Technology Data Exchange (ETDEWEB)

The catalytic pyrolysis of plant biomass was investigated in a dual-particle powder fluidized-bed (PPFB), where the primary decompositions and secondary reactions occurred simultaneously under ambient pressure. The yields and distributions of the pyrolysis products were studied under various operating conditions. In the absence of catalyst, the amount of volatile released from woody biomass depended on the pyrolysis temperature, and only 13.8 g H{sub 2}/kg biomass (def: dry ash-free basis) was produced at 1173 K. NiMo/Al{sub 2}O{sub 3} catalyst promoted the decomposition of tar and light aromatic hydrocarbon compounds from the primary decomposition reaction, and significantly reduced the temperature required for the secondary phase reaction. With NiMo/Al{sub 2}O{sub 3} catalyst at 723 K, clean combustion gas accounted for 91.25 vol% of the total gas products, which was composed of 49.73 vol% of H{sub 2}, 34.50 vol% of CO, and 7.03 vol% of low molecular weight hydrocarbon gases. The contents of H{sub 2} and CO were 33.6 g H{sub 2}/kg biomass (def) and 326.3 g CO/kg biomass (def), respectively. Therefore, it is critical to control the secondary phase reaction conditions during the catalytic pyrolysis in order to produce hydrogen-rich gas. (author)

Qinglan, Hao; Chang, Wang; Yao, Wang; Dan, Li; Guiju, Li [Department of Environmental Science and Engineering, Tianjin University of Science and Technology, Tianjin 300457 (China); Dingqiang, Lu [College of Life Science and Pharmacy, Nanjing University of Technology, Nanjing 210009 (China)

2010-09-15

34

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-01-01

35

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

A biomass waste, rice husk, was inspected by thermoanalytical investigation to evaluate its capability as an adsorbent medium for tar removal. The pyrolysis process has been applied to the rice husk material at different temperatures 600, 800 and 1000 C with 20 C/min heating rate, to investigate two topics: (1) influence of temperature on characterization of rice husk char and; (2) adsorption capability of rice husk char for tar removal. The results showed that subsequent ...

Anchan Paethanom; Kunio Yoshikawa

2012-01-01

36

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

International Nuclear Information System (INIS)

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

37

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

International Nuclear Information System (INIS)

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

38

High temperature rapid pyrolysis of low rank coals and oil shales  

Energy Technology Data Exchange (ETDEWEB)

Rational and complex utilization of cheap low-rank coals and oil shales for technological processing makes it possible to produce directly from solid fuels the valuable commodity products for non-fuel purposes. The production of new materials and chemical products from coals is determined by scientific research and progress in the field of controlled pyrolysis in the widest temperature interval. Many technologies of solid fuel processing are carried out at high temperatures and high speeds of heating. Carbon black with the yield of 25--35% per organic mass of fuel was prepared through the high temperature rapid pyrolysis of fossil fuels. Process was carried out in tube reactors at a temperature about 1400 C. For this purpose not only coking coals but also sapropelic, high volatile coal and oil shale are suitable. Carbon black derived from solid fuels can successfully be applied as a filler producing industrial rubber and electrocarbon products. More than 50% of the grained carbonized residue will be formed during the high temperature rapid pyrolysis of fossil fuels. It has a developed system of pores and good absorptive characteristics. The gaseous products of this process contain hydrogen and carbon oxide mainly.

Malkova, V.V.; Rogaylin, M.I.

1999-07-01

39

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-12-15

40

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

 
 
 
 
41

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

42

Formation of phenols from the low-temperature fast pyrolysis of Radiata pine (Pinus radiata)  

Energy Technology Data Exchange (ETDEWEB)

The pyrolysis of lignocellulose is very complex, due primarily to the inherent complexity of the substrate, which changes continuously both chemically and structurally, throughout the decomposition process. Furthermore, the actual pyrolysis reactions and subsequent secondary decomposition processes are critically influenced by the interaction of mass and heat transport phenomena which are in turn influenced by dimensional, morphological and hydrological substrate parameters as well as the actual design and operational parameters of the pyrolysis reactor system. Consequently, pyrolysis products tend to be highly complex and are of limited commercial value without modification, or 'upgrading'. Relatively little research has focused on the influence of molecular oxygen on the thermal decomposition of lignocellulose under fast pyrolysis conditions. In this study, the influence of molecular oxygen on the formation of low molecular weight phenols from the low-temperature fast pyrolysis of Radiata pine (Pinus radiata) was evaluated. Experimentation was performed on a bench scale fluidised bed reactor operated at 290-295{sup o}C with the oxygen concentration in the fluidising gas being 0, 10 or 20% (v/v). The fluidised bed mass was 135 or 200g and was composed of river sand (310-500{mu}m, quartz/orthoclase mixture) which had been pre-ignited at 600{sup o}C. The Radiata pine substrate (150-250{mu}m) was oven-dried or oven-dried and ethanol extracted. Product analysis was performed using gas chromatography/mass spectroscopy. The phenolic product was dominated by a relatively small number compounds such more than 75% was accounted for by seven compounds. The concentration of phenols in the liquid product was strongly dependent on the concentration of oxygen in the carrier gas and ranged from 0.09% (m/m), when no oxygen was present, to 11.98% (m/m) when the oxygen concentration was 20%. This equated to an absolute yield of 0.02-0.64%, respectively based on oven-dried mass of substrate. The removal of extractives did not influence the process with respect to phenols yield under all conditions evaluated. However, a significant reduction in overall oil yield occurred with extractives removal when pyrolysis was performed using the larger bed mass with the highest carrier gas oxygen concentration. (author)

Butt, David A.E. [School of Forest and Ecosystem Science, University of Melbourne, Water Street, Creswick, Vic. 3363 (Australia)

2006-06-01

43

Fuel and fuel blending components from biomass derived pyrolysis oil  

Science.gov (United States)

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

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

2012-12-11

44

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

45

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.

46

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

47

Influence of Biomass Pyrolysis Temperature, Heating Rate and Type of Biomass on Produced Char in a Fluidized Bed Reactor  

Directory of Open Access Journals (Sweden)

Full Text Available Biomass pyrolysis experiments were carried out in a fluidized bed reactor (FBR and produced char yields were measured for 3 kinds of softwoods, 3 kinds of hardwoods, 2 kinds of herbaceous plants and 3 kinds of agricultural residues. Pyrolysis temperature range was between 300 C and 1200 C, and heating rate was fast (1001000 C/s or slow (10 C/min. After the pyrolysis, produced char was collected with bed particles and only the char was separated from bed particles by sieving. Surface of the produced char was observed by SEM to confirm bed particles adhesion behavior on the surface of char. Char-bed particles (alumina particles adhesion were observed mainly under fast pyrolysis condition for most of the biomass samples. Char yields by fast pyrolysis were much lower than those by slow pyrolysis of Eucalyptus camaldulensis (hardwood, Japanese cypress (softwood, Switchgrass (herbaceous plant and Bagasse (agricultural residue, respectively. In the case of fast pyrolysis condition, char yields from softwood species were lower than those from other biomass species.

Toshiyuki Iwasaki

2014-05-01

48

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

Science.gov (United States)

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

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

2014-07-01

49

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

50

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

51

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.

52

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

53

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

Science.gov (United States)

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

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

2015-02-01

54

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.

55

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

Energy Technology Data Exchange (ETDEWEB)

An analytical method has been developed to quantize 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 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 C. (author)

Ahmad, Tauqeer; Awan, Iftikhar A.; Nisar, Jan [National Center of Excellence in Physical Chemistry, University of Peshawar, Peshawar 25120 (Pakistan); Ahmad, Imtiaz [Institute of Chemical Sciences, University of Peshawar, Peshawar (Pakistan)

2009-05-15

56

High temperature pyrolysis: A new system for isotopic and elemental analysis  

International Nuclear Information System (INIS)

A new method for the automated sample conversion and on-line determination of deuterium, carbon, nitrogen and oxygen isotopes for organic and inorganic substances is presented. The samples are pyrolytically decomposed in presence of reactive carbon in a high temperature pyrolysis system (HTP) at a temperature higher than 1400 deg. C. The method has a great potential for the analysis of hydrogen, carbon, nitrogen and oxygen stable isotopes ratios. The instrumentation and application is very simple and cost effective. The reproducibility of the ?-values is 3 per mille for D/H, 0.3 per mille for 18O, and 0.2 per mille for 13C and 15N respectively. The system is suitable for solid, liquid and gaseous samples. Results are presented for the isotopic composition of international reference materials which show the precision and accuracy of the method. (author)

57

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

58

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

Science.gov (United States)

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

Khan, M. Rashid (Morgantown, WV)

1988-01-01

59

Pyrolysis behavior of tire-derived fuels at different temperatures and heating rates.  

Science.gov (United States)

Pyrolytic product distribution rates and pyrolysis behavior of tire-derived fuels (TDF) were investigated using thermogravimetric analyzer (TGA) techniques. A TGA was designed and built to investigate the behavior and products of pyrolysis of typical TDF specimens. The fundamental knowledge of TGA analysis and principal fuel analysis are applied in this study. Thermogravimetry of the degradation temperature of the TDF confirms the overall decomposition rate of the volatile products during the depolymerization reaction. The principal fuel analysis (proximate and ultimate analysis) of the pyrolytic char products show the correlation of volatilization into the gas and liquid phases and the existence of fixed carbon and other compounds that remain as a solid char. The kinetic parameters were calculated using least square with minimizing sum of error square technique. The results show that the average kinetic parameters of TDF are the activation energy, E = 1322 +/- 244 kJ/mol, a pre-exponential constant of A = 2.06 +/- 3.47 x 10(10) min(-1), and a reaction order n = 1.62 +/- 0.31. The model-predicted rate equations agree with the experimental data. The overall TDF weight conversion represents the carbon weight conversion in the sample. PMID:16739798

Unapumnuk, Kessinee; Keener, Tim C; Lu, Mingming; Khang, Soon-Jai

2006-05-01

60

Indium Oxide Thin-Film Transistors Processed at Low Temperature via Ultrasonic Spray Pyrolysis.  

Science.gov (United States)

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

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

2015-01-14

 
 
 
 
61

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)

62

Pyrolysis and gasification of coal at high temperatures. Quarterly progress report No. 10, December 15, 1989--March 15, 1990  

Energy Technology Data Exchange (ETDEWEB)

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

Zygourakis, K.

1990-12-31

63

The low-temperature pyrolysis of combustible plutonium-contaminated materials (PCM)  

International Nuclear Information System (INIS)

The process of incineration of combustible PCM yields an excellent waste volume reduction, producing an inorganic residue which is both stable for interim storage and is a convenient starting material for any subsequent immobilization process. The ash is physically very suitable for any extraction of plutonium which may be required. However, conventional incinerator temperatures pose materials of construction problems and, in addition, there is evidence that plutonium extraction becomes progressively more difficult as the temperature exceeds the 600-7000C range. Low-temperature pyrolysis seeks to retain the benefits of incineration whilst, by limiting the operating temperature, controlling the problems of corrosion and plutonium extraction. The process involves the low-temperature (500-7000C) treatment of the waste in an inert atmosphere to produce a carbonaceous char, followed by a second, air-oxidation stage, again at low temperature. Primary off-gas treatment by after-burning is envisaged. The results of bench-scale and small-scale pilot plant work to examine these conditions are reported. (author)

64

Evaluation of Integrated Time-Temperature Effect in Pyrolysis Process of Historically Contaminated Soils with Cadmium (Cd and Lead (Pb  

Directory of Open Access Journals (Sweden)

Full Text Available It is already known that heavy metals pollution causes important concern to human and ecosystem health. Heavy metals in soils at the European level represents 37.3% between main contaminates affecting soils (EEA, 2007. This paper illustrates results obtained in the framework of laboratory experiments concerning the evaluation of integrated time-temperature effect in pyrolysis process applied to contaminated soil by two different ways: it is about heavy metals historically contaminated soil from one of the most polluted areas within Romania, and artificially contaminated with PCB-containing transformer oil. In particular, the authors focused on a recent evaluation of pyrolysis efficiency on removing lead (Pb and cadmium (Cd from the contaminated soil. The experimental study evaluated two important parameters related to the studied remediation methodology: thermal process temperature and the retention time in reactor of the contaminated soils. The remediation treatments were performed in a rotary kiln reactor, taking into account three process temperatures (400C, 600C and 800C and two retention times: 30 min. and 60 min. Completed analyses have focused on pyrolysis solids and gas products. Consequently, both ash and gas obtained after pyrolysis process were subjected to chemical analyses.

Bulm?u C

2013-04-01

65

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-08-27

66

Effect of pyrolysis temperature on the mutagenicity of tobacco smoke condensate.  

Science.gov (United States)

Tobacco smoke aerosols with fewer mutagens in the particulate fraction may present reduced risk to the smoker. The objective of this study was to test the hypothesis that the temperature at which tobacco is pyrolyzed or combusted can affect the mutagenicity of the particulate fraction of the smoke aerosol. Tobacco smoke aerosol was generated under precisely controlled temperature conditions from 250 to 550 degrees C by heating compressed tobacco tablets in air. The tobacco aerosols generated had a cigarette smoke-like appearance and aroma. The tobacco smoke aerosol was passed through a Cambridge filter pad to collect the particulate fraction, termed the smoke condensate. Although condensates of tobacco smoke and whole cigarette mainstream smoke share many of the same chemical components, there are physical and chemical differences between the two complex mixtures. The condensates from smoke aerosols prepared at different temperatures were assayed in the Ames Salmonella microsome test with metabolic activation by rat liver S9 using tester strains TA98 and TA100. Tobacco smoke condensates were not detectably mutagenic in strain TA98 when the tobacco smoke aerosol was generated at temperatures below 400 degrees C. Above 400 degrees C, condensates were mutagenic in strain TA98. Similarly, condensates prepared from tobacco smoke aerosols generated at temperatures below 475 degrees C were not detectably mutagenic in strain TA100. In contrast, tobacco tablets heated to temperatures of 475 degrees C or greater generated smoke aerosol that was detectably mutagenic as measured in TA100. Therefore, heating and pyrolyzing tobacco at temperatures below those found in tobacco burning cigarettes reduces the mutagenicity of the smoke condensate. Highly mutagenic heterocyclic amines derived from the pyrolysis of tobacco leaf protein may be important contributors to the high temperature production of tobacco smoke Ames Salmonella mutagens. The relevance of these findings regarding cancer risk in humans is difficult to assess because of the lack of a direct correlation between mutagenicity in the Ames Salmonella test and carcinogenicity. PMID:11313117

White, J L; Conner, B T; Perfetti, T A; Bombick, B R; Avalos, J T; Fowler, K W; Smith, C J; Doolittle, D J

2001-05-01

67

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

Science.gov (United States)

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant worldwide. A detailed examination of the degradation products emitted during thermal decomposition of TBBPA is presented in the study. Runs were performed in a laboratory furnace at different temperatures (650 and 800C) and in different atmospheres (nitrogen and air). More than one hundred semivolatile compounds have been identified by GC/MS, with special interest in brominated ones. Presence of HBr and brominated light hydrocarbons increased with temperature and in the presence of oxygen. Maximum formation of PAHs is observed at pyrolytic condition at the higher temperature. High levels of 2,4-, 2,6- and 2,4,6- bromophenols were found. The levels of polybrominated dibenzo-p-dioxins and furans have been detected in the ppm range. The most abundant isomers are 2,4,6,8-TeBDF in pyrolysis and 1,2,3,7,8-PeBDF in combustion. These results should be considered in the assessment of thermal treatment of materials containing brominated flame retardants. PMID:24792882

Ortuo, Nuria; Molt, Julia; Conesa, Juan A; Font, Rafael

2014-08-01

68

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

Science.gov (United States)

Zinc sulfide (ZnS) thin films have been synthesized by spray pyrolysis at 310 C using an aqueous solution of zinc chloride (ZnCl2) and thioacetamide (TAA). Highly crystalline films were obtained by applying TAA instead of thiourea (TU) as the sulfur source. X-ray diffraction (XRD) analyses show that the films prepared by TAA contained a wurtzite structure, which is usually a high temperature phase of ZnS. The crystallinity and morphology of the ZnS films appeared to have a strong dependence on the spray rate as well. The asymmetric polar structure of the TAA molecule is proposed to be the intrinsic reason of the formation of highly crystalline ZnS at comparatively low temperatures. The violet and green emissions from photoluminescence (PL) spectroscopy reflected the sulfur and zinc vacancies in the film. Accordingly, the photodetectors fabricated using these films exhibit excellent response to green and red photons of 525 nm and 650 nm respectively, though the band gaps of the materials, estimated from optical absorption spectroscopy, are in the range of 3.5-3.6 eV. PMID:23546181

Zeng, Xin; Pramana, Stevin S; Batabyal, Sudip K; Mhaisalkar, Subodh G; Chen, Xiaodong; Jinesh, K B

2013-05-14

69

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

70

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2014-01-01

71

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

72

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

DEFF Research Database (Denmark)

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

Nelissen, Victoria; Ruysschaert, Greet

2014-01-01

73

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

Science.gov (United States)

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

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

2015-01-01

74

Catalytic deoxygenation of liquid biomass for hydrocarbon fuels  

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-03-15

75

Catalytic Oxidation and Deoxygenation of Renewables with Rhenium Complexes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

76

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 (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

77

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...

78

Study of hydrazine deoxygenation in neutral aqueous solution  

International Nuclear Information System (INIS)

The efficiency of hydrazine deoxygenation added catalyst in the neutral aqueous solution is discussed. The test conditions are selected at temperatures of 10 degree C, 20 degree C and 30 degree C, the initial dissolved oxygen concentration of 10.0-10.8mg/L(10 degree C), 8.2-8.6mg/L(20 degree C) and 7.0-7.4mg/L(30 degree C), and the hydrazine dosages are 6 and 3 times of the initial dissolved oxygen concentration. The results show that the dissolved oxygen concentration can be decreased to be 100 ?g/L when the catalyst dosage is within 600 ?g/L-50?g/L. (authors)

79

Wettability of poultry litter biochars at variable pyrolysis temperatures and their impact on soil wettability and water retention relationships  

Science.gov (United States)

To reduce the impact of poultry farming on greenhouse gas emissions, poultry farming waste - poultry litter - can be converted to biofuel and biochar through slow-pyrolysis, with the biochar added to agricultural soil for nutrient enrichment and carbon sequestration. While biochars from source materials other than poultry litter have been shown to sequester carbon and increase soil fertility, there is considerable variability in biochar behavior - even with biochars created from the same source material. This situation is exacerbated by our limited understanding of how biochars alter physical, chemical, and biological processes in agricultural soils. The focus of this work is to develop a mechanistic understanding of how poultry litter (PL) biochars affect the hydrology, microbial communities, N2O emissions, and nitrogen cycling in agricultural soils. The initial focus is on the impact of PL biochar on soil hydrology. PL from Perdue AgriRecycle, LLC (Seaford, Delaware) was used to produce biochars at pyrolysis temperatures from 300C to 600C. To explore the impact of these biochars on soil wettability, the PL biochars were mixed with a 30/40 Accusand in mass fractions from 0% to 100%. The water contact angle was then measured using a goniometer on these sand/biochar mixtures using the sessile drop method and a single layer of sample particles. The PL biochars produced at temperatures between 300C to 400C were hydrophobic, while those pyrolized at > 400C were hydrophilic. Water contact angles for samples with 100% biochar varied systematically with pyrolysis temperature, decreasing from 101.12 to 20.57 as the pyrolysis temperature increased from 300 to 600C. Even for small amounts of hydrophobic biochar added to the hydrophilic sand, the contact angle of the mixture was altered: for sand/biochar mixtures containing only 2% hydrophobic PL biochar by weight, the contact angle of the mixture increased from ~ 8 (0% biochar) to 20 (2% biochar). For higher mass fractions, the impact of hydrophobic PL biochar on the sand/mixture contact angle was more dramatic: for a sand/biochar mixture with 15% PL biochar, the contact angle was 40.12. Water drop penetration tests were also performed on these samples, and results were consistent with contact angles measured with the sessile drop method. To further explore the cause of the varying contact angle with pyrolysis temperature, the PL biochars were vigorously rinsed with deionized water or heated for 24 hours at 105C, and the contact angle measurements repeated. Both rinsing and heating samples rendered hydrophobic PL biochar hydrophilic. Rinsate samples were analyzed for total organic carbon and with GC-MS. These data suggest that bio-oils produced during slow-pyrolysis at temperatures < 400C condensed on biochar and caused hydrophobicity. These bio-oils could be removed through vigorous washing with deionized water or heating to 105C. The implication of these changes in water contact angle from PL biochar addition on water retention relationships for soil and on water distribution within pores will be discussed.

Yi, S. C.; Witt, B.; Guo, M.; Chiu, P.; Imhoff, P. T.

2012-12-01

80

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

Science.gov (United States)

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

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

 
 
 
 
81

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

Science.gov (United States)

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 13MJ/Nm(3)) than HTP because of higher H(2) yield and lower tar content. PMID:19237247

Kantarelis, E; Donaj, P; Yang, W; Zabaniotou, A

2009-08-15

82

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

Energy Technology Data Exchange (ETDEWEB)

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/Nm{sup 3}) than HTP because of higher H{sub 2} yield and lower tar content.

Kantarelis, E. [Department of Chemical Engineering, Aristotle University of Thessaloniki, Un.Box 455, University Campus, GR54124 Thessaloniki (Greece); Donaj, P.; Yang, W. [Royal Institute of Technology (KTH), School of Industrial Engineering and Management, Department of Materials Science and Engineering, Division of Energy and Furnace Technology, SE100 44 Stockholm (Sweden); Zabaniotou, A., E-mail: sonia@cheng.auth.gr [Department of Chemical Engineering, Aristotle University of Thessaloniki, Un.Box 455, University Campus, GR54124 Thessaloniki (Greece)

2009-08-15

83

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. Meanwhil...

Jeon Jong-Ki; Jeong Kwang-Eun; Chae Ho-Jeong; Park Sung Hoon; Lee Hyung Won; Park Young-Kwon

2011-01-01

84

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.

85

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

Science.gov (United States)

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

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

2013-09-01

86

A fuel pyrolysis method  

Energy Technology Data Exchange (ETDEWEB)

In the method for pyrolysis (Pz) of fuels (Tp) through passing them through a melted heat carrier (TN), in order to increase the process effectiveness, the fuels to be pyrolyzed are fed into the melted heat carrier in the form of a sharp stream. The balancing of the temperature of the heat carrier in the heating chambers and the pyrolysis chambers occurs due to mixing of its weight by the sharp stream and through convection.

Chukhanov, Z.F.; Dvoskin, G.I.; Kashurichev, A.P.; Khmelevskaya, Ye.D.; Kurochkin, A.I.; Pulkina, M.K.

1982-01-01

87

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

Science.gov (United States)

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

Ortel, Marlis; Balster, Torsten; Wagner, Veit

2013-12-01

88

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

International Nuclear Information System (INIS)

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

89

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

International Nuclear Information System (INIS)

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

90

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

91

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.

92

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-11-15

93

Study of Surface Cleaning Methods and Pyrolysis Temperature on Nano-Structured Carbon Films using X-ray Photoelectron Spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Nanostructured carbon (ns-C) films fabricated by stabilization and pyrolysis of di-block 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, (2009) 177]. 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 di-block copolymers of polyacrylonitrile-b-poly(n-butyl acrylate) (PAN-b-PBA) 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. % of nitrogen present in the films pyrolyzed at 600 C, suggesting incomplete denitrogenation of the copolymer films. The nitrogen atomic concentration reduced significantly for films pyrolyzed at 900 C confirming extensive denitrogenation at that temperature. Furthermore, quantitative analysis of nitrogen sub-peaks indicated higher loss of nitrogen atoms residing at the edge of graphitic clusters relative to that of nitrogen atoms within the graphitic cluster, 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.

Kerber, Pranita B.; Porter, Lisa M.; McCullough, L. A.; Kowalewski, Tomasz; Engelhard, Mark H.; Baer, Donald R.

2012-10-12

94

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

Science.gov (United States)

Mesoporous SBA-15-based catalysts were applied, for the first time, to the pyrolysis of waste mandarin residue. Si-SBA-15 with few acid sites, Al-SBA-15 with a significant amount of acid sites owing to the alumination treatment, and Pt/Al-SBA-15, which was synthesized by incorporating 7.1-nm Pt nanoparticles on Al-SBA-15, were used. Pyrolysis experiments were conducted by pyrolysis gas chromatography/mass spectroscopy to determine the catalytic activities of the catalysts used. X-ray diffraction, nitrogen adsorption, NH3-temperature-programmed desorption and transmission electron microscopy were used to characterize the catalysts. Al-SBA-15 produced higher quality bio-oil than Si-SBA-15 due to its better deoxygenation and cracking performance stemming from the presence of acid sites. Pt/Al-SBA-15 showed the highest oxygenate conversion as well as the largest yield of high-value-added compounds, such as aromatics, low-molecular-mass hydrocarbons and furans. PMID:23763130

Kim, Jeong Wook; Joo, Sang Hoon; Seo, Bora; Kim, Seong-Soo; Shin, Dae-Hyun; Park, Sung Hoon; Jeon, Jong-Ki; Park, Young-Kwon

2013-04-01

95

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)

96

Reductive deoxygenation of alcohols & Synthesis of novel natural products isolated from Ruscus aculeatus L.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The first part of this work (chapter 1 and 2) deals with the reductive deoxygenation of alcohols. Chapter 1 reviews catalytic deoxygenation methods currently used in organic synthesis. Recent examples are used to demonstrate the different deoxygenation strategies employing either a two-step procedure or the direct deoxygenation of alcohols. Chapter 2 reports the deoxygenation of benzylic alcohols with hydriodic acid in a biphasic media. This method, using boiling hydriodic acid and red phosph...

Herrmann, Josef Maximilian

2014-01-01

97

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

Directory of Open Access Journals (Sweden)

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

R. Chandiramouli

2012-01-01

98

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

99

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-05-01

100

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

Science.gov (United States)

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

 
 
 
 
101

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

102

Catalytic pyrolysis of waste rice husk over mesoporous materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 b...

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

103

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

104

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2004-05-30

105

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.

106

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

Science.gov (United States)

While pyrolysis of livestock manures generates nutrient-rich biochars with potential agronomic uses, studies are needed to clarify biochar properties across manure varieties under similar controlled conditions. This paper reports selected physicochemical results for five manure-based biochars pyrolyzed at 350 and 700C: swine separated-solids; paved-feedlot manure; dairy manure; poultry litter; and turkey litter. Elemental and FTIR analyses of these alkaline biochars demonstrated variations and similarities in physicochemical characteristics. The FTIR spectra were similar for (1) turkey and poultry and (2) feedlot and dairy, but were distinct for swine biochars. Dairy biochars contained the greatest volatile matter, C, and energy content and lowest ash, N, and S contents. Swine biochars had the greatest P, N, and S contents alongside the lowest pH and EC values. Poultry litter biochars exhibited the greatest EC values. With the greatest ash contents, turkey litter biochars had the greatest biochar mass recoveries, whereas feedlot biochars demonstrated the lowest. PMID:22237173

Cantrell, Keri B; Hunt, Patrick G; Uchimiya, Minori; Novak, Jeffrey M; Ro, Kyoung S

2012-03-01

107

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

Energy Technology Data Exchange (ETDEWEB)

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

Nicholas, Christpher P; Boldingh, Edwin P

2013-12-17

108

Catalytic pyrolysis using UZM-39 aluminosilicate zeolite  

Energy Technology Data Exchange (ETDEWEB)

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

Nicholas, Christopher P; Boldingh, Edwin P

2014-10-07

109

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

International Nuclear Information System (INIS)

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

110

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

111

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

112

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

Science.gov (United States)

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

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

2014-08-01

113

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1979-10-01

114

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1979-10-01

115

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1979-10-01

116

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

117

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

118

Thermal glycosylation and degradation reactions occurring at the reducing ends of cellulose during low-temperature pyrolysis.  

Science.gov (United States)

Thermal glycosylation and degradation reactions of cellulose (Avicel PH-101) were studied in the presence or absence of alcohols (glycerol, mannitol, 1,2,6-hexanetriol, 3-phenoxy-1,2-propanediol, and 1-tetradecanol) under N(2) at 60-280C. In the presence of glycerol (heating time, 10 min), the reducing ends were converted into glycosides when the temperature of the glycerol was >140C without the addition of any catalysts. A temperature of 140C is close to that required for the initiation of thermal polymerization (glycosylation). Although the conversion was only around 20% in the range of 140-180C, the reactivity increased above 200-240C where the thermal expansion of cellulose crystals is reported to become significant. Finally, all reducing ends were converted into glycosides at 260C. Such heterogeneous reactivity likely arose from the lower reactivities of the reducing ends in the crystalline region due to their lower accessibility to glycerol, although the reactivity in the non-crystalline region was similar to that of glucose. Alcohols that have a lower OH/C ratio did not react with the reducing ends, suggesting that the hydrophilicity of the alcohol was critical for the glycosylation reaction to proceed. The glycosylated cellulose samples were found to be significantly stabilized against pyrolytic coloration. The results of neat cellulose pyrolysis indicated that two competitive reactions, thermal glycosylation and degradation, formed a dark-colored substance at the reducing ends while the internal glucose units in the cellulose were comparatively stable. PMID:21159331

Matsuoka, Seiji; Kawamoto, Haruo; Saka, Shiro

2011-02-01

119

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

Science.gov (United States)

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

Nicholas, Christopher P; Boldingh, Edwin P

2014-04-29

120

Catalytic pyrolysis using UZM-44 aluminosilicate zeolite  

Energy Technology Data Exchange (ETDEWEB)

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

Nicholas, Christopher P; Boldingh, Edwin P

2013-12-17

 
 
 
 
121

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

Directory of Open Access Journals (Sweden)

Full Text Available The thermal elimination of benzoic acid from (--cocaine is shown to be temperature-dependent. In the temperature range of 200-500 C only a trans-elimination is observed leading to methylecgonidine. Above ca. 500 C a second mechanism, the cis-elimination, comes up yielding a novel alkaloid methylisoecgonidine 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

2011-01-01

122

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.

123

The pyrolysis of a tungsten alkyne complex as a low temperature route to tungsten carbide  

International Nuclear Information System (INIS)

The synthesis of designed organometallic compounds and their selective activation and transformation into materials of high purity (for electronic applications), high strength and/or high temperature stability (for refractory or structural applications), represents a potential area of extreme growth in organometallic chemistry. Research in this area could provide entirely new, inexpensive, fabrication methods for common and exotic materials. In this paper, the authors develop design principles for the preparation of organometallic precursors, ''premetallics'' that can be selectively converted, in high yields, to a desired refractory metal. They also describe preliminary efforts to prepare tungsten carbides (WC/sub x/) from a prematallic

124

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-09-15

125

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.

126

Pyrolysis and oxidative pyrolysis experiments with organization exchange resin  

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-12-31

127

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

International Nuclear Information System (INIS)

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

128

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

129

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

130

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

131

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2003-01-15

132

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

133

Pyrolysis and oxidation of aromatic compounds  

Science.gov (United States)

A study of the questions associated with the use of alternate fuels demands knowledge of the chemical mechanism of pyrolysis and oxidation of aromatic compounds. Both pyrolysis and oxidation are important, because fuel-rich conditions may mean that pyrolysis is competitive with oxidation. Soot formation is certainly a pyrolysis problem. The complexity of system characteristics makes a detailed study of thermodynamical and kinetic conditions difficult. The matter can be simplified somewhat by generalizing the chemistry by classes of molecules. The criteria for such a generalization of the chemistry are discussed along with an evaluation of the rate constants and their temperature and pressure dependences. Attention is given to the pyrolysis of hydrocarbons, the oxidation of hydrocarbons, the oxidation reactions of alkanes, aspects of codification and extrapolation, group additivity, structural consideration, kinetics, and the pyrolysis of aromatic compounds.

Golden, D. M.

1978-01-01

134

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

135

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

136

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

International Nuclear Information System (INIS)

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

137

Structural and optical properties of nanostructural V{sub 2}O{sub 5} thin films deposited by spray pyrolysis technique: Effect of the substrate temperature  

Energy Technology Data Exchange (ETDEWEB)

V{sub 2}O{sub 5} thin films were deposited on glass substrates by spray pyrolysis technique. The variation in the structural and optical properties with a variation in the substrate temperature was investigated by means of X-ray diffraction (XRD) and UVvis spectrophotometer. XRD was used to reveal the possible orientations of crystallites in the films prepared at different substrate temperatures ranging from 200 C to 550 C. The results showed that by increasing the temperature, the films grew along the (001) direction with an orthorhombic structure. The crystallite size was calculated using the Scherrer equation and observed that it increased with elevating the substrate temperature to 450 C, but decreased when further increasing it. The highest transmittance was achieved when films were deposited at 550 C. The absorption edge was estimated by using the Tauc plot. In the range 350 C550 C, a shift of the absorption edge from 2.5 eV to 2.8 eV was observed due to the formation of chemical bonds at the V{sub 2}O{sub 5} filmsubstrate interface at high substrate temperatures (>450 C). Field emission scanning electron microscopy showed that nanorods were formed when depositing at 500 C. We conclude that by altering the substrate temperature the size of crystallites can be well controlled. - Highlights: ? Spray pyrolysis technique was used. ? We have synthesized highly oriented nanocrystalline V{sub 2}O{sub 5} films. ? By altering the substrate temperature the size of crystallites can be well controlled. ? The highest transmittance was achieved when films were deposited at 550 C. ? Scanning electron microscopy showed that nanorods were formed when depositing at 500 C.

Irani, R. [Spray Lab, Physics Department, University of Guilan, Rasht (Iran, Islamic Republic of); Rozati, S.M., E-mail: smrozati@gmail.com [Spray Lab, Physics Department, University of Guilan, Rasht (Iran, Islamic Republic of); Beke, S. [Department of Nanophysics, Istituto Italiano di Tecnologia (IIT), via Morego 30, 16163 Genova (Italy)

2013-05-15

138

Preparing levoglucosan derived from waste material by pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Waste newspaper and waste cotton were pyrolyzed in tubular furnace pyrolysis equipment. This experiment is directed to the influence of pyrolysis temperature on yield of levoglucosan and other pyrolysis products from waste material. The results show that levoglucosan yield is correlate to pyrolysis oil yield. The highest yield of levoglucosan can be obtained when the pyrolysis temperature was around 420 deg C in waste newspaper and 420 deg C in waste cotton. Bio-oil, gas, and char yields of different temperature were also determined. The HPLC analysis shows main composition is acetic acid in aqueous phase while relatively large proportion is levoglucosan in nonaqueous phase. (Author)

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

2004-09-15

139

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

140

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

Science.gov (United States)

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

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

2014-11-01

 
 
 
 
141

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

142

Structural and photoluminescence characterization of SnO{sub 2}: F thin films deposited by advanced spray pyrolysis technique at low substrate temperature  

Energy Technology Data Exchange (ETDEWEB)

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.

Shewale, P.S. [Thin Film Physics Laboratory, Department of Electronics, Shivaji University, Kolhapur 416004 (India); Ung Sim, Kyu; Kim, Ye-bin; Kim, J.H. [Department of Materials Science and Engineering, Chonnam National University, 300 Yongbong-Dong, Buk-Gu, Gwangju 500757 (Korea, Republic of); Moholkar, A.V. [Department of Physics, Shivaji University, Kolhapur 416004 (India); Uplane, M.D., E-mail: mdu_eln@unishivaji.ac.in [Thin Film Physics Laboratory, Department of Electronics, Shivaji University, Kolhapur 416004 (India)

2013-07-15

143

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

144

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

Science.gov (United States)

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

Mahendran, C.; Suriyanarayanan, N.

2010-04-01

145

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2010-04-15

146

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

147

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2012-01-01

148

PYROLYSIS OF TOBACCO RESIDUE: PART 1. THERMAL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Akalin, Mehmet K.; Selhan Karagz

2011-01-01

149

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

150

Pyrolysis of fast-growing aquatic biomass -Lemna minor (duckweed): Characterization of pyrolysis products.  

Science.gov (United States)

The aim of this work was to conduct the experimental study of pyrolysis of fast-growing aquatic biomass -Lemna minor (commonly known as duckweed) with the emphasis on the characterization of main products of pyrolysis. The yields of pyrolysis gas, pyrolytic oil (bio-oil) and char were determined as a function of pyrolysis temperature and the sweep gas (Ar) flow rate. Thermogravimetric/differential thermogravimetric (TG/DTG) analyses of duckweed samples in inert (helium gas) and oxidative (air) atmosphere revealed differences in the TG/DTG patterns obtained for duckweed and typical plant biomass. The bio-oil samples produced by duckweed pyrolysis at different reaction conditions were analyzed using GC-MS technique. It was found that pyrolysis temperature had minor effect on the bio-oil product slate, but exerted major influence on the relative quantities of the individual pyrolysis products obtained. While, the residence time of the pyrolysis vapors had negligible effect on the yield and composition of the duckweed pyrolysis products. PMID:20598878

Muradov, Nazim; Fidalgo, Beatriz; Gujar, Amit C; T-Raissi, Ali

2010-11-01

151

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

152

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

153

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

Science.gov (United States)

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

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

2015-03-01

154

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

155

Effect of substrate temperature on optical, structural and electrical properties of FeSe thin films deposited by spray pyrolysis technique  

Science.gov (United States)

The versatile spray pyrolysis technique was employed to prepare thin films of iron selenide on glass substrates at different substrate temperatures. The deposition temperature was varied between 473 and 673 K. The as-deposited films were characterized by X-ray diffraction (XRD), SEM, optical and electrical characterization techniques. The X-ray studies reveal that the films are nanocrystalline with tetragonal structure and exhibit (101) preferred orientation. The SEM and AFM studies indicate that the film surface is homogenous with no cracks or pinholes and well covers the glass substrate. The film thickness was found to vary from 110 to 230 nm with substrate temperature. The optical band gap was found to decrease from 2.92 to 2.68 eV depending on deposition temperature. The resistivity of p-type FeSe film is of the order of 8104 ? cm and it decreases to 1.5104 ? cm as substrate temperature is increased from 473 K to 673 K.

Ubale, A. U.; Sakhare, Y. S.

2013-10-01

156

Microwave pyrolysis of wheat straw: product distribution and generation mechanism.  

Science.gov (United States)

Microwave pyrolysis of wheat straw is studied, combined with analysis of products, the distribution and generation pathway of products are investigated. Only a small amount of volatiles released when microwave pyrolysis of pure straw. Mixtures of adding CuO and Fe3O4 can pyrolyze, and the majority in pyrolysis products is in liquid-phase. Severe pyrolysis occur after adding carbon residue, the CO content in pyrolysis gas products is high, and the maximum volume content of H2 can exceed 35 vol.%. The high-temperature is helpful for increasing the yield of combustible gas in gaseous products, in particular the H2 production, but also helpful for improving the conversion of sample. Pyrolysis is carried out layer by layer from the inside to outside. As the internal material firstly pyrolyze and pyrolysis products released pass through the low temperature zone, the chance of occurrence of secondary reactions is reduced. PMID:24607465

Zhao, Xiqiang; Wang, Wenlong; Liu, Hongzhen; Ma, Chunyuan; Song, Zhanlong

2014-04-01

157

FAST PYROLYSIS OF ENZYMATIC/MILD ACIDOLYSIS LIGNIN FROM MOSO BAMBOO  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2010-01-01

158

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

Directory of Open Access Journals (Sweden)

Full Text Available

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

2012-12-01

159

Laser induced pyrolysis techniques  

International Nuclear Information System (INIS)

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

160

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

 
 
 
 
161

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

162

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

163

Slow pyrolysis of pistachio shell  

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-08-15

164

Effects of torrefaction and densification on switchgrass pyrolysis products.  

Science.gov (United States)

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

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

2014-12-01

165

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

166

Pyrolysis of composite plastic waste.  

Science.gov (United States)

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

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

2003-05-01

167

Oxygen isotope analysis of carbonates in the calcite-dolomite-magnesite solid-solution by high-temperature pyrolysis: initial results.  

Science.gov (United States)

Accurate and efficient measurement of the oxygen isotope composition of carbonates (delta(C) (18)O) based on the mass spectrometric analysis of CO(2) produced by reacting carbonate samples with H(3)PO(4) is compromised by: (1) uncertainties associated with fractionation factors (alpha(CO)(2)C) used to correct measured oxygen isotope values of CO(2)(delta(CO(2)(18)O) to delta(C) (18)O; and (2) the slow reaction rates of many carbonates of geological and environmental interest with H(3)PO(4). In contrast, determination of delta(C) (18)O from analysis of CO produced by high-temperature (>1400 degrees C) pyrolytic reduction, using an elemental analyser coupled to continuous-flow isotope-ratio mass spectrometry (TC/EA CF-IRMS), offers a potentially efficient alternative that measures the isotopic composition of total carbonate oxygen and should, therefore, theoretically be free of fractionation effects. The utility of the TC/EA CF-IRMS technique was tested by analysis of carbonates in the calcite-dolomite-magnesite solid-solution and comparing the results with delta(C) (18)O measured by conventional thermal decomposition/fluorination (TDF) on the same materials. Initial results show that CO yields are dependent on both the chemical composition of the carbonate and the specific pyrolysis conditions. Low gas yields (+0.2 per thousand) deviations in delta(C(TC/EA) (18)O compared with delta(C(TDF) (18)O. At a pyrolysis temperature of 1420 degrees C the difference between delta(C) (18)O measured by TC/EA CF-IRMS and TDF (Delta(C(TC/EA,TDF) (18)O) was found to be negatively correlated with gas yield (r = -0.785) and this suggests that delta(C) (18)O values (with an estimated combined standard uncertainty of +/-0.38 per thousand) could be derived by applying a yield-dependent correction. Increasing the pyrolysis temperature to 1500 degrees C also resulted in a statistically significant correlation with gas yield (r = -0.601), indicating that delta(C) (18)O values (with an estimated uncertainty of +/-0.43 per thousand) could again be corrected using a yield-dependent procedure. Despite significant uncertainty associated with TC/EA CF-IRMS analysis, the magnitude of the uncertainty is similar to that associated with the application of poorly defined values of alpha(CO)(2), (C) used to derive delta(C) (18)O from delta(CO(2) (18)O measured by the H(3)PO(4) method for most common carbonate phases. Consequently, TC/EA CF-IRMS could provide a rapid alternative for the analysis of these phases without any effective deterioration in relative accuracy, while analytical precision could be improved by increasing the number of replicate analyses for both calibration standards and samples. Although automated gas preparation techniques based on the H(3)PO(4) method (ISOCARB, Kiel device, Gas-Bench systems) have the potential to measure delta(CO)(2) (18)O efficiently for specific, slowly reacting phases (e.g. dolomite), problems associated with poorly defined alpha(CO)(2), (C) remain. The application of the Principle of Identical Treatment is not a solution to the analysis of these phases because it assumes that a single fractionation factor may be defined for each phase within a solid-solution regardless of its precise chemical composition. This assumption has yet to be tested adequately. PMID:18446821

Crowley, Stephen F; Spero, Howard J; Winter, David A; Sloane, Hilary J; Croudace, Ian W

2008-06-01

168

Conventional and microwave induced pyrolysis of coffee hulls for the production of a hydrogen rich fuel gas  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper describes the conventional and microwave-assisted pyrolysis of coffee hulls at 500, 800 and 1000 8C. The influence of the pyrolysis method and temperature on the product yields and on the characteristics of the pyrolysis products is discussed. It was found that the pyrolysis of this particular residue gives rise to a larger yield of the gas fraction compared to the other fractions, even at relatively low temperatures. A comparison of microwave-assisted pyrolysis and conven...

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

2007-01-01

169

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

170

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

171

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

172

SIMULATION OF OLIVE PITS PYROLYSIS IN A ROTARY KILN PLANT  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Giacobbe Braccio; Vincenzo Lorefice; Cesare Freda; Enzo Benanti; Vinod Kumar Sharma

2011-01-01

173

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

International Nuclear Information System (INIS)

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

174

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

International Nuclear Information System (INIS)

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

175

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-12-05

176

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-08-15

177

Pyrolysis and Gasification  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Astrup, Thomas; Bilitewski, B.

2010-01-01

178

Decomposition of ion exchange resins by pyrolysis  

International Nuclear Information System (INIS)

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

179

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

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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. jap...

Lee, Hyung Won; Choi, Suek Joo; Park, Sung Hoon; Jeon, Jong-ki; Jung, Sang-chul; Kim, Sang Chai; Park, Young-kwon

2014-01-01

180

Pyrolysis of waste tyres: A review  

International Nuclear Information System (INIS)

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

 
 
 
 
181

Pyrolysis of waste tyres: A review  

Energy Technology Data Exchange (ETDEWEB)

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

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

2013-08-15

182

Hyperpolarized (129)Xe T (1) in oxygenated and deoxygenated blood  

Science.gov (United States)

The viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other than the lungs depends on whether the spin-lattice relaxation time, T(1), of (129)Xe is sufficiently long in the blood. In previous experiments by the authors, the T(1) was found to be strongly dependent upon the oxygenation of the blood, with T(1) increasing from about 3 s in deoxygenated samples to about 10 s in oxygenated samples. Contrarily, Tseng et al. (J. Magn. Reson. 1997; 126: 79-86) reported extremely long T(1) values deduced from an indirect experiment in which hyperpolarized (129)Xe was used to create a 'blood-foam'. They found that oxygenation decreased T(1). Pivotal to their experiment is the continual and rapid exchange of hyperpolarized (129)Xe between the gas phase (within blood-foam bubbles) and the dissolved phase (in the skin of the bubbles); this necessitated a complicated analysis to extract the T(1) of (129)Xe in blood. In the present study, the experimental design minimizes gas exchange after the initial bolus of hyperpolarized (129)Xe has been bubbled through the sample. This study confirms that oxygenation increases the T(1) of (129)Xe in blood, from about 4 s in freshly drawn venous blood, to about 13 s in blood oxygenated to arterial levels, and also shifts the red blood cell resonance to higher frequency. Copyright 2000 John Wiley & Sons, Ltd. Abbreviations used BOLD blood oxygen level dependent NOE nuclear overhouses effect PO(2) oxygen partial pressure RBC red blood cells RF radio frequency SNR signal-to-noise ratio.

Albert, M. S.; Balamore, D.; Kacher, D. F.; Venkatesh, A. K.; Jolesz, F. A.

2000-01-01

183

PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST  

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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

184

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

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

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

2012-01-01

185

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

Science.gov (United States)

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

McManus, Jesse R.; Vohs, John M.

2014-12-01

186

TBP/kerosene pyrolysis and combustion at pilot scale  

International Nuclear Information System (INIS)

Pyrolysis and combustion technology is an available method to treat spent organic solvent--intermediate level radioactive TBP-kerosene. The pilot system with the treatment capacity of 25 kgh-1 is designed and installed. Influences of technical parameters such as pyrolysis temperature, feeding rate, feed composition, etc, on pyrolysis rate and fixation rate of phosphorus indicate that pyrolysis rate of TBP and fixation rate of phosphorus are more than 99.5% at given condition, the decontamination factors (DF) of U, Sr and Cs in the whole system are more than 106

187

SIMULATION OF OLIVE PITS PYROLYSIS IN A ROTARY KILN PLANT  

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

Giacobbe Braccio

2011-01-01

188

FAST PYROLYSIS OF ENZYMATIC/MILD ACIDOLYSIS LIGNIN FROM MOSO BAMBOO  

Directory of Open Access Journals (Sweden)

Full Text Available The characteristics of enzymatic/mild acidolysis lignin (EMAL isolated from moso bamboo were investigated using pyrolysis-gas chromato-graphy/mass spectrometry (Py-GC/MS. Pyrolysis temperature as a factor on products was studied, and the pyrolysis mechanism was inferred with respect to the dominating products. Research results showed that pyrolysis products derived from EMAL pyrolysis were mainly heterocyclic (2,3-dihydrobenzofuran, phenols, esters, and a minor amount of acetic acid. Pyrolysis temperature had a distinct impact on yields of pyrolysis products. As pyrolysis temperature increased, the yield of 2,3-dihydrobenzofuran rapidly decreased; however, yields of phenols increased smoothly. It can be obtained that, at the low temperatures (250-400oC, pyrolysis products were mainly 2,3-dihydrobenzofuran, and the highest yield was 66.26% at 320oC; at the high temperatures (400-800oC, pyrolysis products were mainly phenols, and yields hit their highest level of 56.43% at 600 oC. A minor amount of acetic acid only emerged at 800C. Knowledge of pyrolysis products releasing from EMAL and the pyrolysis mechanism could be basic and essential to the understanding of thermochemical conversion of EMAL to chemicals or high-grade energy.

Rui Lou

2010-05-01

189

FAST PYROLYSIS OF LIGNINS  

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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

190

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

191

Thermogravimetric Analysis and Global Kinetics of Segregated MSW Pyrolysis  

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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

192

Kinetics of gas-phase pyrolysis of dimethyltellurium and dimethylselenium  

Energy Technology Data Exchange (ETDEWEB)

The authors construct a kinetic model for the pyrolysis of dimethyltellurium and dimethylselenium and and discuss the effects of pyrolysis conditions on the subsequent vapor phase epitaxy and chemical vapor deposition of tellurium and selenium for the purpose of optimizing the deposition process and the semiconducting properties of the films. Temperature and pressure dependence are outlined and the reactor is described.

Yablokov, V.A.; Dozorov, A.V.; Zorin, A.D.; Feshchenko, I.A.; Ronina, O.V.; Karataev, E.N.

1987-01-10

193

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2011-03-25

194

Gas chromatography mass spectrometric quantitative determination of product distribution of paper pyrolysis with solid acids at low temperature  

International Nuclear Information System (INIS)

Paper was pyrolyzed at low temperature (300 degree C) both in the absence and presence of catalysts. The liquid products were collected and characterized by using GC/MS. Boric acid and aluminum sulphate acting as catalysts were found to alter the relative concentration and nature of the product due to depolymerizing, polarizing and free radical stabilizing properties. Boric acid was found to decrease the amount of anhydro sugars and favors the formation of esters, ketones and carboxylic acids. Aluminum sulphate favored the formation of furan carboxaldehyde, phenols and other cyclic compounds The cracking of paper and formation of new compounds was facilitated by vacant orbital of the catalyst. Therefore change in concentration of catalyst also changed the nature and concentration of the products. These observations are explained on the basis of the chemical nature of these compounds in this paper. (author)

195

Pyrolysis of Phenolic Impregnated Carbon Ablator (PICA).  

Science.gov (United States)

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

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

2015-01-28

196

Microwave induced pyrolysis of oil palm biomass.  

Science.gov (United States)

The purpose of this paper was to carry out microwave induced pyrolysis of oil palm biomass (shell and fibers) with the help of char as microwave absorber (MA). Rapid heating and yield of microwave pyrolysis products such as bio-oil, char, and gas was found to depend on the ratio of biomass to microwave absorber. Temperature profiles revealed the heating characteristics of the biomass materials which can rapidly heat-up to high temperature within seconds in presence of MA. Some characterization of pyrolysis products was also presented. The advantage of this technique includes substantial reduction in consumption of energy, time and cost in order to produce bio-oil from biomass materials. Large biomass particle size can be used directly in microwave heating, thus saving grinding as well as moisture removal cost. A synergistic effect was found in using MA with oil palm biomass. PMID:20970995

Salema, Arshad Adam; Ani, Farid Nasir

2011-02-01

197

CHARACTERISTICS OF CORN STALK HEMICELLULOSE PYROLYSIS IN A TUBULAR REACTOR  

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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

198

Pyrolysis reduces radioactive waste  

International Nuclear Information System (INIS)

A number of processes have been developed for nuclear waste management on the basis of basic chemical engineering operations such as precipitation, sedimentation, filtration, ion exchange distillation, and degassing. A new process is described which is based on pyrolysis. (orig.)

199

Novel technique for coal pyrolysis and hydrogenation product analysis  

Energy Technology Data Exchange (ETDEWEB)

A microjet reactor coupled to a VUV photoionization time-of-flight mass spectrometer has been used to obtain species measurements during high temperature pyrolysis and oxidation of a wide range of hydrocarbon compounds ranging from allene and acetylene to cyclohexane, benzene and toluene. Initial work focused on calibration of the technique, optimization of ion collection and detection and characterization of limitations. Using the optimized technique with 118 nm photoionization, intermediate species profiles were obtained for analysis of the hydrocarbon pyrolysis and oxidation mechanisms. The soft'' ionization, yielding predominantly molecular ions, allowed the study of reaction pathways in these high temperature systems where both sampling and detection challenges are severe. Work has focused on the pyrolysis and oxidative pyrolysis of aliphatic and aromatic hydrocarbon mixtures representative of coal pyrolysis and hydropyrolysis products. The detailed mass spectra obtained during pyrolysis and oxidation of hydrocarbon mixtures is especially important because of the complex nature of the product mixture even at short residence times and low primary reactant conversions. The combustion community has advanced detailed modeling of pyrolysis and oxidation to the C4 hydrocarbon level but in general above that size uncertainties in rate constant and thermodynamic data do not allow us to a priori predict products from mixed hydrocarbon pyrolyses using a detailed chemistry model. For pyrolysis of mixtures of coal-derived liquid fractions with a large range of compound structures and molecular weights in the hundreds of amu the modeling challenge is severe. Lumped models are possible from stable product data.

Pfefferle, L.D.; Boyle, J.

1993-03-15

200

FAST PYROLYSIS OF LIGNINS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 li...

Sedat Beis; Saikrishna Mukkamala; Nathan Hill; Jincy Joseph; Cirila Baker; Bruce Jensen; Elizabeth Stemmler; Clayton Wheeler; Brian Frederick; Adriaan van Heiningen; Alex Berg; William Joseph DeSisto

2010-01-01

 
 
 
 
201

I/Ca evidence for upper ocean deoxygenation during the PETM  

Science.gov (United States)

global warming affects marine ecosystems in complex ways, and declining ocean oxygenation is a growing concern. Forecasting the geographical and bathymetric extent, rate, and intensity of future deoxygenation and its effects on oceanic biota, however, remains highly challenging because of the complex feedbacks in the Earth-ocean biota system. Information on past global warming events such as the Paleocene-Eocene Thermal Maximum (PETM, ~55.5 Ma), a potential analog for present and future global warming, may help in such forecasting. Documenting past ocean deoxygenation, however, is hampered by the lack of sensitive proxies for past oceanic oxygen levels throughout the water column. As yet no evidence has been presented for pervasive deoxygenation in the upper water column through expansion of oxygen minimum zones (OMZs). We apply a novel proxy for paleoredox conditions, the iodine to calcium ratio (I/Ca) in bulk coarse fraction sediment and planktonic foraminiferal tests from pelagic sites in different oceans, and compared our reconstruction with modeled oxygen levels. The reconstructed iodate gradients indicate that deoxygenation occurred in the upper water column in the Atlantic, Indian Oceans, and possibly the Pacific Ocean, as well during the PETM, due to vertical and potentially lateral expansion of OMZs.

Zhou, Xiaoli; Thomas, Ellen; Rickaby, Rosalind E. M.; Winguth, Arne M. E.; Lu, Zunli

2014-10-01

202

Involvement of deoxygenation-induced increase in tyrosine kinase activity in sickle cell dehydration.  

Science.gov (United States)

Deoxygenation of sickle (SS) cells causes cationic alterations leading to cell dehydration by various mechanisms, including activation of Ca2+-sensitive K channels and possibly of K-Cl cotransport. Since an abnormal tyrosine kinase (TK) activity exists in SS cells we investigated the possible role of tyrosine phosphorylation in SS cell dehydration. In density-fractionated SS reticulocytes and discocytes, but not in normal red cells, deoxygenation increased membrane and cytosolic TK activities and tyrosine phosphorylation of band 3, independently of external Ca2+. These effects were abolished by the TK inhibitors methyl 2, 5-dihydroxycinnamate (DiOH) or tyrphostin 47 (T47). Deoxygenation-induced Ca2+ uptake was not affected by the inhibitors and Na+ gain was reduced by T47 and not by DiOH. Both inhibitors decreased the loss of K+ and cellular dehydration. The effect of the inhibitors on K+ efflux was still observed in the absence of external Ca2+. These data indicate that the TK inhibitors do not interfere with deoxygenation-induced membrane permeabilization, but affect Ca2+-independent K+ efflux. It cannot be excluded, however, that the TK inhibitors also attenuate Ca2+-sensitive K+ efflux. Based on recent evidence from the literature, it is suggested that the diminution of K+ efflux results in part from inhibition of K-Cl cotransport activity. PMID:9644211

Merciris, P; Hardy-Dessources, M D; Sauvage, M; Giraud, F

1998-08-01

203

Deoxygenation of polyhydroxybenzenes: an alternative strategy for the benzene-free synthesis of aromatic chemicals.  

Science.gov (United States)

New synthetic connections have been established between glucose and aromatic chemicals such as pyrogallol, hydroquinone, and resorcinol. The centerpiece of this approach is the removal of one oxygen atom from 1,2,3,4-tetrahydroxybenzene, hydroxyhydroquinone, and phloroglucinol methyl ether to form pyrogallol, hydroquinone, and resorcinol, respectively. Deoxygenations are accomplished by Rh-catalyzed hydrogenation of the starting polyhydroxybenzenes followed by acid-catalyzed dehydration of putative dihydro intermediates. Pyrogallol synthesis consists of converting glucose into myo-inositol, oxidation to myo-2-inosose, dehydration to 1,2,3,4-tetrahydroxybenzene, and deoxygenation to form pyrogallol. Synthesis of pyrogallol via myo-2-inosose requires 4 enzyme-catalyzed and 2 chemical steps. For comparison, synthesis of pyrogallol from glucose via gallic acid intermediacy and the shikimate pathway requires at least 20 enzyme-catalyzed steps. A new benzene-free synthesis of hydroquinone employs conversion of glucose into 2-deoxy-scyllo-inosose, dehydration of this inosose to hydroxyhydroquinone, and subsequent deoxygenation to form hydroquinone. Synthesis of hydroquinone via 2-deoxy-scyllo-inosose requires 2 enzyme-catalyzed and 2 chemical steps. By contrast, synthesis of hydroquinone using the shikimate pathway and intermediacy of quinic acid requires 18 enzyme-catalyzed steps and 1 chemical step. Methylation of triacetic acid lactone, cyclization, and regioselective deoxygenation of phloroglucinol methyl ether affords resorcinol. Given the ability to synthesize triacetic acid lactone from glucose, this constitutes the first benzene-free route for the synthesis of resorcinol. PMID:12022810

Hansen, Chad A; Frost, J W

2002-05-29

204

Catalytic Pyrolysis and a Pyrolysis Kinetic Study of Shredded Printed Circuit Board for Fuel Recovery  

Directory of Open Access Journals (Sweden)

Full Text Available Scrap printed circuit boards (PCBs are the most abundant wastes that can be found in the landfills in Malaysia and this disposal certainly poses serious detrimental to the environment. This research aims to investigate optimum temperature for pyrolyzing waste PCBs, find out the best catalyst to be used in accelerating PCBs pyrolysis, select suitable ratio of catalyst to PCBs for higher oil yield and examine kinetics pyrolysis of the waste PCBs decomposition. Operating temperatures ranged from 200 to 350 ?C of PCBs pyrolysis were conducted with the optimum temperature obtained was 275 ?C. Fluid cata-lytic cracking (FCC catalyst, zeolite socony mobil-5 (ZSM-5, H-Y-type zeolite and dolomite were used to accelerate PCBs pyrolysis at 275 ?C and FCC was identified as the best catalyst to be used. Differ-ent ratios of FCC to waste PCBs such as 10:90, 20:80, 30:70, 40:60 and 50:50 were applied in the pyro-lysis at 275 ?C and ratio of 10:90 was selected as the suitable ratio to be utilized for maximum yield. The kinetic study was done through thermogravimetric analysis on waste PCBs under various heating rates and different particle sizes. The GC-MS analysis revealed that compounds detected in the pyro-oil have the potential to be used as fuel. 2014 BCREC UNDIP. All rights reservedReceived: 23rd July 2014; Revised: 14th August 2014; Accepted: 14th August 2014 How to Cite: Ng, C.H., Salmiaton, A., Hizam, H. (2014. Catalytic Pyrolysis and a Pyrolysis Kinetic Study of Shredded Printed Circuit Board for Fuel Recovery. Bulletin of Chemical Reaction Engineering & Catalysis, 9 (3: 224-240. (doi:10.9767/bcrec.9.3.7148.224-240 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.9.3.7148.224-240

Salmiaton Ali

2014-10-01

205

Influence of Pyrolysis Temperature and Type of Ligno-Cellulose and Cellulose Biomass on Yield, Specific Surface Area and Mechanical Resistance of Active Coal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the Czech Republic, there are many contaminated agricultural soils due to anthropogenic activity and geogenic origin. The contaminated biomass of plants grown on the contaminated soils needs to be appropriately disposed of to prevent the re-releace of heavy metals into the environment. One way of processing contaminated biomass is pyrolysis, where the heavy metals are concentrated in biochar (active coal). This can be applied to soil where it improves the physical properties. The aim of ...

Pohor?ely?, Michael

2012-01-01

206

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

207

Pyrolysis of scrap tyres with zeolite USY  

International Nuclear Information System (INIS)

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

208

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.

209

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

210

CATALYTIC THERMAL DECOMPOSITION OF POLYETHYLENE BY PYROLYSIS GAS CHROMATOGRAPHY  

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

JAN NISAR

2011-01-01

211

CATALYTIC THERMAL DECOMPOSITION OF POLYETHYLENE BY PYROLYSIS GAS CHROMATOGRAPHY  

Scientific Electronic Library Online (English)

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

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

212

Pyrolysis and Gasification  

DEFF Research Database (Denmark)

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

Astrup, Thomas; Bilitewski, B.

2011-01-01

213

PYROLYSIS AND COMBUSTION OF SCRAP TIRE  

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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

214

Toxicity of Pyrolysis Gases from Elastomers  

Science.gov (United States)

The toxicity of the pyrolysis gases from six elastomers was investigated. The elastomers were polyisoprene (natural rubber), styrene-butadiene rubber (SBR), ethylene propylene diene terpolymer (EPDM), acrylonitrile rubber, chlorosulfonated polyethylene rubber, and polychloroprene. The rising temperature and fixed temperature programs produced exactly the same rank order of materials based on time to death. Acryltonitrile rubber exhibited the greatest toxicity under these test conditions; carbon monoxide was not found in sufficient concentrations to be the primary cause of death.

Hilado, Carlos J.; Kosola, Kay L.; Solis, Alida N.; Kourtides, Demetrius A.; Parker, John A.

1977-01-01

215

Microwave pyrolysis of microalgae for high syngas production  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2013-01-01

216

Theoretical analysis of crosstalk between oxygenated and deoxygenated haemoglobin in focal brain-activation measurements by near-infrared topography  

Science.gov (United States)

The crosstalk between concentration changes in oxygenated haemoglobin and deoxygenated haemoglobin calculated by the modified Lambert-Beer law in near-infrared topography is theoretically investigated. The changes in intensity detected with probe pairs on the scalp caused by the concentration change in either oxygenated or deoxygenated haemoglobin induced by the focal brain activation is predicted by Monte Carlo simulation. The topographic images of the changes in oxygenated and deoxygenated haemoglobin are obtained from the changes in the intensity of light at two wavelengths detected by probe pairs to evaluate the crosstalk. The crosstalk slightly depends on the positional relationship between the probe arrangement and the focal brain activation and is minimised when the focal brain activation is located below a measurement point that is the midpoint between a probe pair. The 690-/830-nm wavelength pair is practically effective for reducing the crosstalk, especially the crosstalk from oxygenated haemoglobin to deoxygenated haemoglobin, in the NIR topography.

Kawaguchi, H.; Okui, N.; Sakaguchi, K.; Okada, E.

2008-12-01

217

Phase modulation system for dual wavelength difference spectroscopy of hemoglobin deoxygenation in tissues  

Science.gov (United States)

Time resolved spectroscopy of tissue makes it possible to quantify tissue hemoglobin concentrations because of the direct measurement of the optical path length for photon migration. However, the laser system is bulky and unwieldy and impractical for clinical studies. Thus, the application of the more compact and efficient phase modulation technology well known for fluorescence lifetime studies to time resolved spectroscopy of tissue offers opportunities to simplify the methodology and in addition to afford continuous readout of tissue photon propagation. This paper describes single and dual wavelength systems operating at two wavelengths in the deep red region based upon a time-sharing system. These devices have noise levels in a 2 Hz bandwidth of less than 2 ps and drifts of < 1ps/min. Applications of the noninvasive devices include measurement of hemoglobin deoxygenation in brain and hemoglobin and myoglobin deoxygenation in human skeletal muscle and animal models. Numerous applications to medical and biological problems now become available.

Chance, Britton; Maris, Michael B.; Sorge, J.; Zhang, M. Z.

1990-05-01

218

Gold Nanoparticle-Catalyzed Environmentally Benign Deoxygenation of Epoxides to Alkenes  

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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

219

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

International Nuclear Information System (INIS)

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

220

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

Energy Technology Data Exchange (ETDEWEB)

Fluidized bed flash pyrolysis experiments have been conducted on a sample of jatropha oil cake to determine particularly the effects of particle size, pyrolysis temperature and nitrogen gas flow rate on the pyrolysis yields. The particle size, nitrogen gas flow rate and temperature of jatropha oil cake were varied from 0.3 to 1.18 mm, 1.25 to 2.4 m{sup 3}/h and 350 to 550 C. The maximum oil yield of 64.25 wt% was obtained at a nitrogen gas flow rate of 1.75 m{sup 3}/h, particle size of 0.7-1.0 mm and pyrolysis temperature of 500 C. The calorific value of pyrolysis oil was found to be 19.66 MJ/kg. The pyrolysis gas can be used as a gaseous fuel. (author)

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

2010-07-15

 
 
 
 
221

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

International Nuclear Information System (INIS)

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

222

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

223

ENGINEERING BULLETIN: PYROLYSIS TREATMENT  

Science.gov (United States)

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

224

Vacuum pyrolysis of waste tires with basic additives  

International Nuclear Information System (INIS)

Granules of waste tires were pyrolyzed under vacuum (3.5-10 kPa) conditions, and the effects of temperature and basic additives (Na2CO3, NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 deg. C to 600 deg. C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48 wt% was achieved at 550 deg. C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50 wt% was achieved at 480 deg. C by adding 3 wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) ?205 deg. C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39 wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na2CO3 addition. Pyrolysis gas was mainly composed of H2, CO, CH4, CO2, C2H4 and C2H6. Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5 wt%) was much higherve 11.5 wt%) was much higher

225

Thermal analysis of charring materials based on pyrolysis interface model  

Directory of Open Access Journals (Sweden)

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

Huang Hai-Ming

2014-01-01

226

TG-DSC-FTIR Analysis of Cyanobacteria Pyrolysis  

Science.gov (United States)

Pyrolysis of cyanobacteria from Dianchi lake was investigated by TG-DSC-FTIR analysis at different heating rates (10, 20, 40C/min). The results indicated that the pyrolysis of cyanobacteria can be divided into four stages: evaporation, depolymerization, devolatilization and carbonization. Meanwhile, the initial weight-loss temperature, weight-loss extreme position, endothermic and exothermic peaks were moved to higher temperature with the increaseing of the heating rate. The kinetic analysis was made with Popescu method. It indicated that the best kinetic model for the pyrolysis of cyanobacteria was the cylindrical symmetry of the phase boundary reaction model. The main pyrolysis gases checked with real-time online FTIR were HCN, NH3, CO, CO2, water vapor and hydrocarbons.

Supeng, Luo; Guirong, Bao; Hua, Wang; Fashe, Li; Yizhe, Li

227

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

228

Phosphate ester cleavage in ribose-5-phosphate induced by OH radicals in deoxygenated aqueous solution  

International Nuclear Information System (INIS)

The reaction of OH radicals and H atoms with ribose-5-phosphate (10-2M) in deoxygenated aqueous solution at room temperature (dose-rate 2.1 x 1017 eV/ml . min, dose 5 x 1018 to 15 x 1018 eV/ml) led to the following dephosphorylation products (G-values): ribo-pentodialdose 1 (0.2), 2-hydroxy-4-oxo-glutaraldehyde 2 (0.06), 5-deoxy-erythro-pentos-4-ulose 3 (0.1) and 3-oxo-glutaraldehyde 4 (0.06). In addition, some minor phosphate free products (total G = 0.09) were formed. G(inorganic phosphate) = 1.3 and G(H2O2) = 0.3. On the addition of 10-3 M Fe(III) ions, G(1) and G(3) increased to 0.6 and 0.4, respectively. In the presence of 10-3M Fe(II), G(1) and G(3) changed to 0.4 amd 0.8, respectively. The other dephosphorylation products were suppressed by the iron ions. G(1) also increased on the addition of increasing amounts of H2O2. Each product could be assigned a precursor radical formed by hydrogen abstraction from C-5, C-4 or C-3 of the ribose-5-phosphate molecule. Products 1 and 2 were formed by oxydative dephosphorylation of an ?-phospho radical with preceding H2O elimination for product 2. Elimination of H3PO4 from a ?-phospho radical led to product 3; product 4 was formed by elimination of two molecules of H2O from its precursor radical and hydrolytic cleavage of an enol phosphate bond. Deuterium-labelling experhosphate bond. Deuterium-labelling experiments and the effects of the iron ions and of H2O2 support the mechanisms proposed. The importance of the dephosphorylation mechanisms for the formation of strand breaks in DNA is discussed with special reference to the effects of the radiosensitizers. (author)

229

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

230

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

231

Slow Pyrolysis of Cassava Wastes for Biochar Production and Characterization  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Nurhidayah Mohamed Noor; Adilah Shariff; Nurhayati Abdullah

2012-01-01

232

Influence of Pyrolysis Parameters on the Performance of CMSM  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Carbon hollow fiber membranes have been prepared by pyrolysis of a P84/S-PEEK blend. Proximate analysis of the precursor was performed using thermogravimetry (TGA), and a carbon yield of approximately 40% can be obtained. This study aimed at understanding the influence of pyrolysis parametersend temperature, quenching effect, and soaking timeon the membrane properties. Permeation experiments were performed with N2, He, and CO2. Scanning electron microscopy (SEM) has been don...

Campo, Marta C.; Tymen Visser; Kitty Nijmeijer; Matthias Wessling; Magalh Amp Es, Fern Amp O. D.; Mendes, Ad Amp Lio M.

2009-01-01

233

SPHERICAL CALCIA STABILIZED ZIRCONIA POWDERS OBTAINED BY SPRAY PYROLYSIS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Physical and chemical properties of ceramic powders are highly dependent on the morphology and chemical composition of the precursor powders. Therefore, properties of ceramic powders are expecting to be improved by controlling the most important parameters of morphology such as composition of precursors, temperature and airflow. Promising techniques to produce ceramic powders with controlled morphology are sol-gel, coprecipitation, and pyrolysis. Among these techniques, spray pyrolysis is one...

Esparza-ponce, H. E.; Reyes-rojas, A.; Miki Yoshida, M.

2001-01-01

234

[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

235

Gas evolution kinetics of two coal samples during rapid pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Quantitative gas evolution kinetics of coal primary pyrolysis at high heating rates is critical for developing predictive coal pyrolysis models. This study aims to investigate the gaseous species evolution kinetics of a low rank coal and a subbituminous coal during pyrolysis at a heating rate of 1000 C s{sup -} {sup 1} and pressures up to 50 bar using a wire mesh reactor. The main gaseous species, including H{sub 2}, CO, CO{sub 2}, and light hydrocarbons CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 6}, C{sub 3}H{sub 8}, were quantified using high sensitivity gas chromatography. It was found that the yields of gaseous species increased with increasing pyrolysis temperature up to 1100 C. The low rank coal generated more CO and CO{sub 2} than the subbituminous coal under similar pyrolysis conditions. Pyrolysis of the low rank coal at 50 bar produced more gas than at atmospheric pressure, especially CO{sub 2}, indicating that the tar precursor had undergone thermal cracking during pyrolysis at the elevated pressure. (author)

Chen, L.; Zeng, C.; Guo, X.; Mao, Y.; Zhang, Y.; Zhang, X.; Li, W. [Coal Polygeneration Tech Laboratory, GE Global Research - Shanghai, Shanghai, 201203 (China); Long, Y. [Material Characterization Laboratory, GE Global Research - Shanghai, Shanghai, 201203 (China); Zhu, H. [Functional Materials Laboratory, GE Global Research - Shanghai, Shanghai, 201203 (China); Eiteneer, B. [Fuel Conversion Laboratory, GE Global Research - Irvine, California 92618 (United States); Zamansky, V. [Energy and Propulsion Technologies, GE Global Research - Irvine, California 92618 (United States)

2010-08-15

236

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

Science.gov (United States)

The depletion of fossil fuel resources and the environmental consequences of their use have dictated the development of new sources of energy that are both sustainable and economical. Biomass has emerged as a renewable carbon feedstock that can be used to produce chemicals and fuels traditionally obtained from petroleum. The oxygen content of biomass prohibits its use without modification because oxygenated hydrocarbons are non-volatile and have lower energy content. Chemical processes that eliminate oxygen and keep the carbon backbone intact are required for the development of biomass as a viable chemical feedstock. This dissertation reports on the kinetic and mechanistic studies conducted on high and low temperature catalytic processes for deoxygenation of biomass precursors to produce high-value chemicals and fuels. Low temperature, steady state reaction studies of acetic acid and ethanol were used to identify co-adsorbed acetic acid/ethanol dimers as surface intermediates within specific elementary steps involved in the esterification of acetic acid with ethanol on zeolites. A reaction mechanism involving two dominating surface species, an inactive ethanol dimeric species adsorbed on Bronsted sites inhibiting ester formation and a co-adsorbed complex of acetic acid and ethanol on the active site reacting to produce ethyl acetate, is shown to describe the reaction rate as a function of temperature (323 -- 383 K), acetic acid (0.5 -- 6.0 kPa), and ethanol (5.0 -- 13.0 kPa) partial pressure on proton-form BEA, FER, MFI, and MOR zeolites. Measured differences in rates as a function of zeolite structure and the rigorous interpretation of these differences in terms of esterification rate and equilibrium constants is presented to show that the intrinsic rate constant for the activation of the co-adsorbed complex increases in the order FER methane (CH3COOH/CH4 = 0.04-0.10, HCOOH/CH 4 = 0.01-0.03, CO2/CH4 = 0.01-0.03) on Mo/H-ZSM-5 formulations at 950 K and atmospheric pressure in an effort to couple deoxygenation and dehydrogenation reaction sequences results instead in a two-zone, stratified bed reactor configuration consisting of upstream oxygenate/CH4 reforming and downstream CH4 dehydroaromatization. X-ray absorption spectroscopy and chemical transient experiments show that molybdenum carbide is formed inside zeolite micropores during CH4 reactions. The addition of an oxygenate co-feed causes oxidation of the active molybdenum carbide catalyst while producing CO and H2 until completely converted. Forward rates of C6H6 synthesis are unperturbed by the introduction of an oxygenate co-feed after rigorously accounting for the thermodynamic reversibility caused by the H2 produced in oxygenate reforming reactions and the fraction of the active catalyst deemed unavailable for CH 4 dehydroaromatization. All effects of co-processing C1-2 oxygenates and molecular H2 with CH4 can be interpreted in terms of an approach to equilibrium. Co-processing H2O, CO2, or light (C1-2, C/Heff catalysts results in complete fragmentation of the oxygenate and CO as the sole oxygen-containing product. The C/Heff accounts for removal of O as CO and describes the net C6H6 and total hydrocarbon synthesis rates at varying (0.0-0.10) C1-2 oxygenate and H2 to CH4 co-feed ratios. Co-processing larger (C 3-5, C/Heff ? 0.25) oxygenates with CH4 results in incomplete fragmentation of the co-fed oxygenate and preferential pathways of C6H6 synthesis that exclude CH4 incorporation. This results in greater net C6H6 synthesis rates than would be predicted from observations made when co-processing C1-2 oxygenates. Catalytic technologies have served a crucial role in processing petroleum feedstocks and are faced with new challenges as the feedstock shifts to chemically diverse but renewable biomass sources. This research addresses these challenges at fundamental and applied levels as it offers t

Bedard, Jeremy William

237

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

238

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

Energy Technology Data Exchange (ETDEWEB)

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

Cho, Pyung Yeon

2011-02-15

239

Effects of effluents and water pressure on oil generation during confined pyrolysis and high-pressure hydrous pyrolysis  

Science.gov (United States)

In order to test experimentally the effects of hydrostatic pressure on oil generation from source rocks, immature Woodford shale was pyrolyzed in confined (Au cells + external pressure = effluents pressure) and hydrous (water pressure) conditions (260-365C during 72 h) at pressures ranging between 220 and 1300 bars. Comparisons of the results obtained in both systems also allowed the effect of the presence of water to be investigated. Increasing the external hydrostatic pressure in confined pyrolysis retards the oil potential consumption in the kerogen. However, the effect of pressure on the yields of extractable organic matter is limited. In hydrous pyrolysis, increasing water pressure significantly lowers the total yields of bitumen + expelled fraction and the consumption of the oil potential in the extracted solid residue is correspondingly reduced. The quantitative composition of the pyrolyzates is significantly affected, although, the C15 + n-alkane distributions do not show significant variations. The total yields of pyrolyzates are similar in confined pyrolysis and hydrous pyrolysis performed between 300 and 700 bars. However, during equivalent time-temperature-pressure experiments, the degradation rates of kerogen and asphaltenes is lower in hydrous pyrolysis than in confined pyrolysis. The very different effects of increasing effluent pressure (confined pyrolysis) and water pressure on oil generation indicate that the nature of the pressurizing medium is an important factor. Tentative explanations are given to elucidate these differences, as well as to estimate the importance of the effects of pressure in the natural environment.

Michels, R.; Landais, P.; Torkelson, B. E.; Philp, R. P.

1995-04-01

240

Modeling the pyrolysis process of biomass particles  

Energy Technology Data Exchange (ETDEWEB)

The use of biomass as replacement for fossil fuel has increasing interest. Since biomass is considered a sustainable energy source, the use of biomass is regarded as a solution to environmental problems and depleting energy supplies. Co-firing in pulverized coal furnaces is a common application of woody biomass. In these furnaces small fuel particles are combusted for electricity production. Due to differences in chemical and physical properties, replacing coal with biomass means that the combustion behavior inside the furnace changes. One of the main differences is the large amount of volatiles that is produced during biomass combustion. These volatiles are produced during the pyrolysis process. The goal of this investigation is to determine the influence of temperature, particle size and fuel properties on the conversion process of biomass. Therefore the pyrolysis process of biomass particles has been investigated. This has been done by modeling the pyrolysis processes governing the conversion of a single biomass particle. This has been approached in two steps. First, the chemistry without transport of wood pyrolysis has been investigated. This has been done by a literature study concerning the chemical composition and structure of woody biomass, reaction schemes describing biomass pyrolysis and kinetics of the concerning reactions. Second, the homogeneous model is extended to a particle model by introducing transport effects. With this model the effect of temperature of the environment and particle geometry has been investigated. The chemical pyrolysis model consists of a fuel model using three model species, namely hemicellulose, cellulose and lignin. Each fuel species is converted via two competing reactions into gasses and char. Gaseous product species are predicted using conservation of elements and enthalpy. By using two competing reactions, the effect of decreasing char yields for increased temperatures has been included. The results of the model have been compared with literature data. The particle model has subsequently been used to investigate the role of parameters controlling the transport of heat inside the particle. These are properties like conductivity, temperature, density and porosity. The chemical model predicts a decrease in char yields for increasing heating rates, this is inline with literature. The composition of gas phase products shows large differences with literature, most likely due to the absence of tar products in the model. From the particle model can be concluded that particles with diameters up to 2.0 mm are mainly controlled by chemical kinetics. Using a heating rate of 100 K/s, the model predicts a conversion time of approximately 9.5 seconds. The model also shows that gas phase chemistry is of minor importance inside the particle.

Van de Weerdhof, M.W.

2010-06-15

 
 
 
 
241

Pyrolysis of Spent Ion Exchange Resins - 12210  

International Nuclear Information System (INIS)

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

242

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

243

Effect of Operating Conditions on Product Distributions and Bio-oil Ageing in Biomass Pyrolysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Alternatives to petroleum-derived fuels are receiving significant interest in order to reduce dependence on finite resources of fossil fuels and to lower fossil-derived CO2 emissions. The present study addresses the production of bio-oil from biomass pyrolysis, one of the potential renewable substitutes to petroleum-derived fuels. The first objective of this work was to investigate the effect of pyrolysis operating parameters, i.e. temperature, heating rate and pyrolysis time, ...

Somrang, Yatika

2012-01-01

244

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

Brownsort, Peter A.

2009-01-01

245

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

International Nuclear Information System (INIS)

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

246

Biomass fast pyrolysis in fluidized bed : product cleaning by in-situ filtration  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis is dedicated to the subject of fast pyrolysis in a fluid bed reactor. A large part of the work is related to reactor design aspects of fast pyrolysis, a subject that has not been considered sufficiently. Past research efforts were focussed mainly on the kinetics of wood pyrolysis and the testing of different reactor types by measuring the bio-oil yield as a function of the reactor temperature.

Wang, Xiaoquan

2006-01-01

247

Multiwall carbon nanotubes from pyrolysis of tetrahydrofuran  

International Nuclear Information System (INIS)

Multiwalled carbon nanotubes have been prepared by pyrolysing tetrahydrofuran (THF) in the presence of nickelocene. Pyrolysis of the precursor mixture has been achieved at temperature as low as 600 deg. C. In this simple approach no carrier gas has been used. The yield of purified carbon nanotubes is found to be more than 65%. Characterization of the as-prepared and purified nanotubes are done by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy and Raman spectra

248

Organic emissions from coal pyrolysis: mutagenic effects.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

1987-01-01

249

Refining fast pyrolysis of biomass  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pyrolysis oil produced from biomass is a promising renewable alternative to crude oil. Such pyrolysis oil has transportation, storage, and processing benefits, none of which are offered by the bulky, inhomogeneous solid biomass from which it originates. However, pyrolysis oil has both a different composition to and different properties from crude oil. This makes its direct use in those applications and conversion processes originally developed for fossil feeds problematic. Improvement of t...

Westerhof, Roel Johannes Maria

2011-01-01

250

Microwave pyrolysis of microalgae for high syngas production.  

Science.gov (United States)

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

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

2013-09-01

251

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

252

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)

253

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

254

Olive bagasse (Olea europa L.) pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

Olive bagasse (Olea europea L.) was pyrolysed in a fixed-bed reactor. The effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rates on the yields of the products were investigated. Pyrolysis runs were performed using pyrolysis temperatures between 350 and 550 {sup o}C with heating rates of 10 and 50 {sup o}C min{sup -} {sup 1}. The particle size and sweep gas flow rate varied in the ranges 0.224-1.8 mm and 50-200 cm{sup 3} min {sup -1}, respectively. The bio-oil obtained at 500 {sup o}C was analysed and at this temperature the liquid product yield was the maximum. The various characteristics of bio-oil obtained under these conditions were identified on the basis of standard test methods. The empirical formula of the bio-oil with heating value of 31.8 MJ kg{sup -1} was established as CH{sub 1.65}O{sub 0.25}N{sub 0.03}. The chemical characterization showed that the bio-oil obtained from olive bagasse may be potentially valuable as a fuel and chemical feedstock. (author)

Sensoz, S.; Demiral, I. [Osmangazi Univ., Eskisehir (Turkey). Dept. of Chemical Engineering; Gercel, H.F. [Anadolu Univ., Eskisehir (Turkey). Dept. of Chemical Engineering

2006-02-15

255

Catalytic Deoxygenation of Renewable Chemicals Structure?Performance Studies  

DEFF Research Database (Denmark)

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

Malcho, Phillip

2014-01-01

256

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

Energy Technology Data Exchange (ETDEWEB)

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

Jang, Hun; Cho, Hyun Chul; Kim, Byoung Koo; Kim, In Sup; Jang, Chang Heui [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Kim, Byoung Koo [Doosan Heavy Industries and Construction Co., Ltd., Changwon (Korea, Republic of)

2007-07-01

257

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

Science.gov (United States)

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

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

1995-01-01

258

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

Science.gov (United States)

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

Wang, Wen-Liang; Chang, Jian-Min; Cai, Li-Ping; Shi, Sheldon Q

2014-12-01

259

A practical approach for modelling and control of biomass pyrolysis pilot plant with heat recovery from combustion of pyrolysis products  

Energy Technology Data Exchange (ETDEWEB)

A pilot plant of biomass pyrolysis using pyrolysis products as fuel has been tested and shown to improve energy balance of the process and to be environmentally friendly by avoiding rejection of pyrolysis pollutants fumes into the atmosphere. The high number of parameters involved in a pyrolysis process makes it difficult to specify an optimum procedure for charcoal yield and pyrolysis cycle durability. So the knowledge of the essential parameters which govern the kinetics mechanisms of the biomass thermal decomposition and the combustion of pyrolysis gases is very useful to understand the operating cycle of the plant. In the present study a thermochemical model is developed in order to simulate and control the operating cycle of the system. The effect of the inlet molar air flow rate on the temporal evolution of biomass mass loss rate and temperatures in the different active zones of the pilot plant as well as the determination of the critical inlet molar air flow rate for which accidental runaway of combustion reactions occurs are presented. To avoid this accidental phenomenon a Proportional-Integral-Derived (PID) anticipated regulation is used in order to control temperatures evolution in the different zones of the device and avoid the runaway of combustion reactions. (author)

Abbassi, Mohamed Ammar; Grioui, Najla; Halouani, Kamel [Micro-Electro-Thermal Systems - Industrial Energy Systems Group (METS-ENIS), IPEIS, University of Sfax, B.P: 1172 - 3018, Sfax (Tunisia); Zoulalian, Andre [Laboratoire d' Etudes et de Recherches sur le Materiau Bois (LERMAB), Universite Henri Poincare Nancy 1 (UHP), B.P: 239 - 54506 Vandoeuvre, les Nancy Cedex (France); Zeghmati, Belkacem [LAMPS-GME, Universite de Perpignan Via Domitia, 52, Avenue Paul Alduy 66860 Perpignan Cedex (France)

2009-10-15

260

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

 
 
 
 
261

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

262

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.

263

Thermogravimetric analysis and fast pyrolysis of Milkweed.  

Science.gov (United States)

Pyrolysis of Milkweed was carried out in a thermogravimetric analyzer and a bubbling fluidized bed reactor. Total liquid yield of Milkweed pyrolysis was between 40.74% and 44.19 wt% between 425 C and 550 C. The gas yield increased from 27.90 wt% to 33.33 wt% with increasing reaction temperature. The higher heating values (HHV) of the Milkweed bio-oil were relatively high (30.33-32.87 MJ/kg) and varied with reaction temperature, feeding rate and fluidization velocity. The selectivity for CO2 was highest within non-condensable gases, and the molar ratio of CO2/CO was about 3 at the different reaction conditions. The (13)C NMR analysis, of the bio-oil showed that the relative concentration carboxylic group and its derivatives was higher at 425 C than 475 C, which resulted in slightly higher oxygen content in bio-oil. The pH of aqueous phase obtained at 475 C was 7.37 which is the highest reported for any lignocellulosic biomass pyrolysis oils. PMID:25064334

Kim, Seung-Soo; Agblevor, Foster A

2014-10-01

264

Microwave Heating Applied to Pyrolysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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

2011-01-01

265

Kinetics of scrap tyre pyrolysis under vacuum conditions  

International Nuclear Information System (INIS)

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

266

Pyrolysis of Softwood Carbohydrates in a Fluidized Bed Reactor  

Directory of Open Access Journals (Sweden)

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

Dmitry Yu. Murzin

2008-09-01

267

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

268

Pyrolysis of methane by microwaves. Pt. 1  

International Nuclear Information System (INIS)

The pyrolysis of methane and mixtures of argon-methane by microwaves (2,450 MHz) was investigated. The microwave plasma diagnostic study was performed using electrical probes, namely, the double floating probe technique. Parameters such as electric field strength and current densities were measured and from their relationship the electron temperature, electric conductivity, electron and ion densities were evaluated as function of gas pressure, microwave power input and distance of the probe from the microwave cavity. Various spectroscopic techniques were used for the measurement of temperatures in the microwave plasma; the 'reversal temperature' by measuring the intensities of the electronic vibrational bands of CN and OH molecules and 'rotational temperature' from the measured intensities of rotational OH lines. The 'rotational' as well as the 'reversal temperature' were found to be identical and this temperature was assumed to be the temperature of the gas in the microwave plasma. Energy balance calculation, based upon the electrical energy input and thermal losses, were performed in order to determine if steady state conditions existed in the microwave plasma. Emission and absorption spectroscopy were used for determining the active species formed in the pyrolysis of methane and also of mixtures of CH4-Ar, by the microwave plasma. (orig.)

269

Utilization of rapid pyrolysis coal tar as a binder for formed fuel production  

Energy Technology Data Exchange (ETDEWEB)

Studies binder properties of black coal tar for briquetting of coal. Three types of coal tar were tested: 1. rotary oven pyrolysis tar (pyrolysis temperature of 520-550 C), 2. rotary oven pyrolysis tar as in 1. but with light oil removed, and 3. fluidized bed pyrolysis tar (pyrolysis temperature 550-560 C). Physical-chemical properties of the tars were analyzed and tabulated prior to their further processing. Tar hardening experiments were carried out at 150-200 C over 300-5,400 seconds and by blowing air, determining dependence of softening point from process temperatures and air velocity. Plotted results proved that this process consisted of 2 stages: distillation and hardening/oxidation. Hardened tars were used in production of briquets. Mechanical strength of briquets was satisfactory. 12 refs.

Banak-Tabkowska, J. (Politechnika Krakowska (Poland). Instytut Chemii i Technologii Organicznej)

1990-12-01

270

Preparation of YBCO superconducting films by spray pyrolysis method  

International Nuclear Information System (INIS)

The methodology for the preparation of YBCO superconducting films on Zr2O(Y) substrates by spray pyrolysis method is reported. The transition temperature of these films is superior than the boiling temperature of liquid 2N. Other critical parameters are similar to those reported by other authors using the same technique

271

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

Science.gov (United States)

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

272

Laboratory evaluation of a Pd-based catalyst for deoxygenation of stator cooling water  

Energy Technology Data Exchange (ETDEWEB)

The water-cooled stator windings in turbine generators suffer from various forms of corrosion induced by the presence of dissolved oxygen. In the current study, various laboratory experiments were conducted to identify a suitable catalyst for the deoxygenation of stator cooling water (SCW) systems and to qualify the material to be used in a field trial in order to confirm its deoxygenation performance. The work focused on evaluating the Lanxess (formerly Bayer) Lewatit K 7333 catalyst with respect to its physical, chemical, and oxidation stability through accelerated ageing tests as well as its performance under extreme dissolved oxygen and hydrogen concentrations. Potential effects of any water extractable leachables from the catalyst on the materials of construction of the SCW system were also studied. The catalyst was effective in removing dissolved oxygen in the presence of dissolved hydrogen and should be able to meet or exceed the dissolved oxygen specifications ({<=} 20 {mu}g . kg{sup -1}) for SCW stations that operate under low-oxygen mode. (orig.)

Dias, Shelton; Rudolph, Andreas [Kinectrics Inc., Toronto, ON (Canada)

2010-02-15

273

Fast pyrolysis of biomass: a handbook  

Energy Technology Data Exchange (ETDEWEB)

This handbook is based on the final report of the International Energy Agency's (IEA) Bioenergy sponsored Pyrolysis Activity. Topics reviewed cover the fast pyrolysis of biomass for producing fuels and chemicals; the IEA pyrolysis fundamentals review; the nature and properties of biomass pyrolysis materials; storage and handling of flash pyrolysis oil; testing standard methods; new methods for chemical and physical characterisation and Round Robin testing; proposed specifications for various grades of pyrolysis oils; the determination of biodegradation rates of bio-oil by respirometry; environment, health and safety issues; and the toxicity of biomass pyrolysis liquids.

Bridgwater, A.; Czernik, S.; Diebold, J.; Meier, D.; Oasmaa, A.; Peacocke, C.; Piskorz, J.; Radlein, D.

1999-05-01

274

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

Science.gov (United States)

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

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

1992-01-01

275

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

Science.gov (United States)

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

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

1998-10-13

276

Pyrolysis characteristics of Oriental white oak: Kinetic study and fast pyrolysis in a fluidized bed with an improved reaction system  

Energy Technology Data Exchange (ETDEWEB)

The kinetic parameters for the pyrolysis of Oriental white oak were evaluated by thermogravimetric analysis (TGA). The white oak was pyrolyzed in a fluidized bed reactor with a two-staged char separation system under a variety of operating conditions. The influence of the pyrolysis conditions on the chemical and physical characteristics of the bio-oil was also examined. TGA showed that the Oriental white oak decomposed at temperatures ranging from 250 to 400 C. The apparent activation energy ranged from 160 to 777 kJ mol{sup -} {sup 1}. The optimal pyrolysis temperature for the production of bio-oil in the fluidized bed unit was between 400 and 450 C. A much smaller and larger feed size adversely affected the production of bio-oil. A higher fluidizing gas flow and higher biomass feeding rate were more effective in the production of bio-oil but the above flow rates did not affect the bio-oil yields significantly. Recycling a part of the product gas as a fluidizing medium resulted the highest bio-oil yield of 60 wt.%. In addition, high-quality bio-oil with a low solid content was produced using a hot filter as well as a cyclone. With exception of the pyrolysis temperature, the other pyrolysis conditions did not significantly affect the chemical and physical characteristics of the resulting bio-oil. (author)

Park, Hyun Ju; Park, Young-Kwon; Dong, Jong-In; Kim, Joo-Sik [Faculty of Environmental Engineering, University of Seoul, Seoul 130-743 (Korea); Jeon, Jong-Ki [Department of Chemical Engineering, Kongju National University, Gongju 341-701 (Korea); Kim, Seung-Soo [Department of Chemical Engineering, Kangwon National University, Samcheok 245-711 (Korea); Kim, Jinsoo [College of Environment and Applied Chemistry, Kyung Hee University, Yongin 449-701 (Korea); Song, Byungho [Department of Chemical Engineering, Kunsan National University, Gunsan 573-701 (Korea); Park, Junhong [School of Mechanical Engineering, Hanyang University, Seoul 133-791 (Korea); Lee, Kyung-Jin [Department of Materials Science and Engineering, Korea University, Seoul 136-173 (Korea)

2009-02-15

277

Pyrolysis characteristics of Shenhua direct liquefaction residue  

Energy Technology Data Exchange (ETDEWEB)

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

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

2009-08-15

278

Norms and standards for fast pyrolysis liquids  

Energy Technology Data Exchange (ETDEWEB)

The International Energy Agency-European Union (IEA-EU) round robin test in 2000 was carried out by learning from earlier round robin tests and by employing improved analytical methods. In general, the accuracy of all physical analyses was good for homogenous pyrolysis liquids. For heterogeneous liquids, erroneous results were obtained, especially for kinematic viscosity and stability index. Good laboratory practice, such as proper calibration of equipment, and good background knowledge of the analysis sample, prevents systematic errors. The main conclusions were: Karl-Fischer titration is recommended for analysing water in pyrolysis liquids. the solids content determined as ethanol insolubles is accurate for white wood (stem wood, no bark or needles) liquids, while a more powerful solvent, like a mixture of methanol and dichloromethane (1:1vol.%), is required for extractive-rich liquids from feedstocks such as forest residues. for elemental analysis at least triplicates are recommended due to the small sample size. Special attention should be paid to nitrogen standards. They should have a similar range of nitrogen as the sample. Kinematic viscosity is an accurate method at 40{sup o}C for pyrolysis liquids. Rotating viscotesters with a cover at low temperatures (|50{sup o}C) can also be used. Stability index needs more specific instructions. Results of chemical characterisation were not very consistent. Proper standard solutions have to be used with known amounts of compounds for quantitative analyses.

Oasmaa, Anja [VTT Processes, P.O. Box 1601, 02044 VTT, Jyvaskyla (Finland); Meier, Dietrich [Federal Research Centre for Forestry and Forest Products, Institute for Wood Chemistry and Chemical Technology of Wood, P.O. Box 800209, D-21002 Hamburg (Germany)

2005-06-15

279

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

280

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 (600 C) 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 220 C for 3 h 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

 
 
 
 
281

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

282

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2008-03-15

283

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

Science.gov (United States)

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

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

2014-10-01

284

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

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

Kunio Yoshikawa

2012-12-01

285

Rapid conversion of tar and char from pyrolysis of a brown coal by reactions with steam in a drop-tube reactor  

Energy Technology Data Exchange (ETDEWEB)

Yallourn brown coal particles were heated at rates in the order of 10{sup 3} K s{sup -1} and pyrolyzed in a drop-tube reactor (DTR) and a Curie-point reactor (CPR). In DTR the vapor-phase secondary reactions of volatiles occurred concurrently with the primary reactions within the particle, while in CPR the volatiles were swept out of the heating zone immediately after formed so that their secondary reactions were suppressed. The char yields for the pyrolyses in these two reactors were described by the same functions of temperature. The evaluation was done by a parameter, {Delta}Y(i), defined as {Delta}Y(i) = Y(i){sub DT}Y(i){sub CP} where Y(i){sub DT} and Y(i){sub CP} are the yields of volatile product i for pyrolyses in DTR and CPR, respectively. {Delta}(tar) decreased with increasing pyrolysis temperature, but was negligible at temperatures below 873 K. {Delta}Y(tar) at 1173 K was much lower than that expected when Y(tar){sub DT} was assumed to decrease only due to dealkylation to form gaseous hydrocarbons and deoxygenation to form CO. The difference between the above two {Delta}T(tars) was explained by the reaction of tar with steam above 1073 K and resulting in a considerable decrease in {Delta}Y(H{sub 2}O) and the corresponding increase in {Delta}Y(CO) and {Delta}Y(H{sub 2}). The addition of steam to the carrier nitrogen gas further promoted the reduction of Y(tar){sub DT} and {Delta}Y(tar) to 1 and -23 mol, respectively. The reduction of {Delta}Y(tar) for the pyrolysis of acid-washed coal was much less significant than that for the original coal. Thus the observed steam reforming of tar was found to be catalyzed by Fe, Ca and/or Mg species that were initially dispersed in the coal matrix as ion-exchanged cations. The addition of steam also increased the total conversion of carbon into volatiles at 1173 K from 44 to 56 mol, indicating the gasification of char by steam within an estimated residence time of coal/char particles. 34 refs., 9 figs., 2 tabs.

Hayashi, J.; Takahashi, H.; Iwatsuki, M.; Essaki, K.; Tsutsumi, A.; Chiba, T. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology

2000-03-01

286

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

287

The capability of studying pyrolysis in a model installation  

Energy Technology Data Exchange (ETDEWEB)

A system is presented and an installation is described for pyrolysis of a hydrocarbon raw material (benzine with a final boiling point of 180 degrees, which chiefly contains n-alkanes and isoalkanes, 81 percent, and 17.05 percent cyclanes; the content of aromatic hydrocarbons (ArU) is 1.55 percent) in a temperature range of 800 to 840 degrees in a steel, tubular horizontal reactor (a diameter of 10 millimeters). Analysis of the liquid products of the pyrolysis was conducted using gas liquid chromatography (GZhKh), and that of the gaseous products, through a gas chromatography method. A comparison, of the outputs of the products in the described laboratory installation in industrial conditions is satisfactory, especially at high temperatures. The installation may be used for unambiguous, rapid and comparitively inexpensive evaluation of the suitability of a raw material for pyrolysis.

Mikulec, J.

1983-01-01

288

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

289

Experimental Research of Pyrolysis Gases Cracking on Surface of Charcoal  

Science.gov (United States)

For several years, in the Joint Institute for High Temperatures of Russian Academy of Sciences, two-stage technology of biomass processing has been developing [1]. The technology is based on pyrolysis of biomass as the first stage. The second stage is high-temperature conversion of liquid fraction of the pyrolysis on the surface of porous charcoal matrix. Synthesis gas consisted of carbon monoxide and hydrogen is the main products of the technology. This gas is proposed to be used as fuel for gas-engine power plant. For practical implementation of the technology it is important to know the size of hot char filter for full cracking of the pyrolysis gases on the surface of charcoal. Theoretical determination of the cracking parameters of the pyrolysis gases on the surface of coal is extremely difficult because the pyrolysis gases include tars, whose composition and structure is complicated and depends on the type of initial biomass. It is also necessary to know the surface area of the char used in the filter, which is also a difficult task. Experimental determination of the hot char filter parameters is presented. It is shown that proposed experimental method can be used for different types of biomass.

Kosov, Valentin; Kosov, Vladimir; Zaichenko, Victor

290

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

Science.gov (United States)

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

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

1990-01-02

291

A comprehensive study of methyl decanoate pyrolysis  

International Nuclear Information System (INIS)

The thermal decomposition of methyl decanoate (MD) was studied in a bench-scale pyrolysis set-up equipped with a dedicated on-line analysis section including a GC GC-FID/(TOF-MS). This analysis section enables quantitative and qualitative on-line analyses of the entire reactor effluent with high level of detail including measurement of formaldehyde and water. The reactor temperature was varied from 873 K to 1123 K at a fixed pressure of 1.7 bar and a fixed residence time of 0.5 s, for both high (10molN2/molMD) and low (0.6molN2/molMD) nitrogen dilution. Thus covering a wide conversion range in both dilution regimes. In these experiments, significant amounts of large linear olefins and unsaturated esters were observed at lower temperatures, the amounts of which decreased at higher temperatures in favor of permanent gasses (CO, CO2, CH4) and light olefins. At the highest temperatures more than 5 wt% of mono-aromatic and poly-aromatic components were observed. The acquired dataset was used to validate 3 recently published microkinetic models which were developed to model oxidation and/or pyrolysis of methyl decanoate. The results showed that these models accurately predict the product distribution, although important discrepancies were observed for some major products such as certain unsaturated esters, CO2 and H2O. Reaction path analyses and CBS-QB3 quantum-chemical calculations are presented and discussed in order to explain the observed differences. -- Highlights: ? New extensive experimental dataset for the pyrolysis of methyl decanoate in a tubular reactor. ? A dedicated separation section including on-line GC GC allows to obtain quantitative data for over 150 components. ? High level ab-initio calculations for important reactions of the methyl decanoate decomposition. ? Identification of missing reactions/reaction families/inaccurate kinetics in the presently available kinetic models.

292

Pyrolysis of corncobs at fluidization  

Energy Technology Data Exchange (ETDEWEB)

Pyrolysis of corncob particles was conducted in nitrogen in an externally heated benchscale fluidized bed reactor. Test results are presented with a demonstration of their application in gasification modelling. (author).

Hongming Jiang; Morey, R.V. (Minnesota Univ., St. Paul, MN (United States). Dept. of Agricultural Engineering)

1992-01-01

293

ESR study of deoxygenated and oxidated forms of vanadium(4) porphyrins  

International Nuclear Information System (INIS)

Halogenated and oxidated forms of porphyrins of oxovanadium VOP (ethioporphyrin-EP and tetraphenylporphyrin) with different halides are studied using the ESR method. In reactions of vanadylporphyrins with metal halides deoxygenation of vanadyl ion is realized and octahedral complex of dihalogenovanadium (4) of porphyrin (P) are formed and at the intermediate stage bimetal complex of vanadiumporphyrin with halide is formed, in which halide cation is bonded by means of the bridge oxygen atom with vanadium ion. In dihalide complexes VX2-P for vanadium (4) ion a regular octahedral surrounding is realized and the axis of tetragonal distortion can be oriented both in perpendicular and lay in porphyrin plane. The oxidated forms, formed during oxidation in the presence of halides, present dihalide vanadium (4) complexes with mono- and dication of porphyrin ligand

294

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

International Nuclear Information System (INIS)

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

295

Pyrolysis of organic binders, Part II. Characteristics of the product  

Energy Technology Data Exchange (ETDEWEB)

The paper analyses properties of petroleum residue produced during vacuum petroleum distillation. The petroleum residue is used as a binder during brown and black coal briquetting. Binder properties, particularly thermal decomposition, influence combustion and pyrolysis of coal briquets. The analysis concentrates on products of petroleum residue pyrolysis from a temperature of 670 K to 1200 K. Solid, gaseous and liquid pyrolysis products are evaluated. Thermal decomposition of the tested binder starts at 670 K, however, yield of the solid, liquid and gaseous products is low. From 710 K to 740 K decomposition of organic matter in the binder is intensive. In this temperature interval about 70% of liquid and gaseous products is formed. With increasing pyrolysis temperature the yield of solid products declines and the yield of gaseous and liquid products increases. With temperature increase composition and structure of decomposition products change. In solid products an increase of the atomic ratio C/H and an increase of structure order occurs. Liquid products consist first of all of methane as well as hydrogen sulfide, hydrogen, carbon monoxide and carbon dioxide. In the liquid products with medium molar mass from 250 to 290 content of aromatic hydrocarbons increases with growing temperature whereas content of alkanes and cycloalkanes decreases.

Wieckowska, J.

1982-08-01

296

Novel technique for coal pyrolysis and hydrogenation product analysis. Final technical report  

Energy Technology Data Exchange (ETDEWEB)

A microjet reactor coupled to a VUV photoionization time-of-flight mass spectrometer has been used to obtain species measurements during high temperature pyrolysis and oxidation of a wide range of hydrocarbon compounds ranging from allene and acetylene to cyclohexane, benzene and toluene. Initial work focused on calibration of the technique, optimization of ion collection and detection and characterization of limitations. Using the optimized technique with 118 nm photoionization, intermediate species profiles were obtained for analysis of the hydrocarbon pyrolysis and oxidation mechanisms. The ``soft`` ionization, yielding predominantly molecular ions, allowed the study of reaction pathways in these high temperature systems where both sampling and detection challenges are severe. Work has focused on the pyrolysis and oxidative pyrolysis of aliphatic and aromatic hydrocarbon mixtures representative of coal pyrolysis and hydropyrolysis products. The detailed mass spectra obtained during pyrolysis and oxidation of hydrocarbon mixtures is especially important because of the complex nature of the product mixture even at short residence times and low primary reactant conversions. The combustion community has advanced detailed modeling of pyrolysis and oxidation to the C4 hydrocarbon level but in general above that size uncertainties in rate constant and thermodynamic data do not allow us to a priori predict products from mixed hydrocarbon pyrolyses using a detailed chemistry model. For pyrolysis of mixtures of coal-derived liquid fractions with a large range of compound structures and molecular weights in the hundreds of amu the modeling challenge is severe. Lumped models are possible from stable product data.

Pfefferle, L.D.; Boyle, J.

1993-03-15

297

Pyrolysis of furan in a microreactor  

Science.gov (United States)

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

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

2013-09-01

298

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 cocaine in the vapor during the course of volatilization revealed high concentrations during the first two min and low concentrations for the remaining time

299

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

300

Si nanocrystals obtained through polymer pyrolysis  

International Nuclear Information System (INIS)

In this letter, we report the formation of bulk samples of silica-based glass containing Si nanocrystals (Si-ncs) by pyrolysis of a preceramic precursor. The starting precursor is a sol-gel-derived polysiloxane containing only Si-H groups which leads, after annealing in a controlled atmosphere in the range 1000-1200 deg. C, to the precipitation of Si-ncs. Characterization of the nanostructure was performed by x-ray diffraction and Raman scattering analyses. Room-temperature luminescence experiments show the interesting optical properties of the Si-ncs/SiO2 material

 
 
 
 
301

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

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

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

2011-01-01

302

High-energy (neodymium) laser pyrolysis of US coals  

Energy Technology Data Exchange (ETDEWEB)

As part of a study exploring conditions that influence coal pyrolysis, the effects of neodymium laser heating upon five different rank coals ahve been studied. Gaseous products from neodymium-laser pyrolysis of all coal types can be explained by condensation reactions during the cooling of high-temperature systems. The use of neutral or reducing atmospheres (helium, hydrogen or deuterium at two atmospheres) does not significantly alter the product distributions, although some deuteration of products was observed. High-speed photography was used to determine the dynamics of the laser interactions. 1 figure, 4 tables.

Vanderborgh, N.E.; Verzino, W.J.; Fletcher, M.A.; Nichols, B.A.

1982-06-01

303

Study of extraction and pyrolysis of Jordan tar sand  

Energy Technology Data Exchange (ETDEWEB)

The extraction and pyrolysis of tar sand from Wadi Isal, Jordan have been investigated. Solvent type, mixing time, temperature, particle size and alkali concentration have been identified as important parameters for bitumen recovery. The results show that hot water extraction is ineffective since a small amount of bitumen has been obtained even at 80degC. Kerosene extraction shows a maximum bitumen recovery of about 43% at 80degC and 180-250 {mu}m particle size. The kinetic parameters of pyrolysis have been determined based on first-order rate expression and their values were in agreement with other published data in the literature. (Author)

Khraisha, Yahya H. [Jordan Univ., Chemical Engineering Dept., Amman (Jordan)

1999-07-01

304

Pyrolysis of activated sludge: Energy analysis and its technical feasibility.  

Science.gov (United States)

A comprehensive study on the potential of pyrolysis of activated sludge to generate substances that can be used to produce energy was evaluated for its technical and environmental viability. The products of the process viz., pyrolysis gas, pyrolysis oil and char can readily be used by the major energy consumers viz., electricity and transportation. Based on the results obtained it is estimated that a 1ton capacity process for pyrolysis of activated sludge can serve the electrical needs of a maximum of 239, 95 and 47 Indian houses per day, considering lower middle class, middle class and upper middle class, respectively. In addition the process would also produce the daily methane (CNG) requirement of 128 public transport buses. The process was determined to be technically feasible at low and medium temperatures for both, pyrolysis gas and electrical energy. The gas generated could be utilized as fuel directly while the oil generated would require pretreatment before its potential application. The process is potentially sustainable when commercialized and can self-sustain in continuous mode of operation in biorefinery context. PMID:25451771

Agarwal, Manu; Tardio, James; Venkata Mohan, S

2015-02-01

305

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...

306

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

307

Release of nitrogen during coal pyrolysis and combustion  

Energy Technology Data Exchange (ETDEWEB)

The relationship between NOx emission and nitrogen behaviour in coal during pyrolysis and combustion was investigated using a bench scale fluidized bed combustor and a TGA-FTIR system. The effects of coal type, temperature, excess air ratio and heating rate on emission of NOx were studied. 3 refs., 4 figs., 1 tab.

Heltsley, R.; Ke-Chang Xie; Xiaofeng Qi; Ying Gao; Wei-Ping Pan; Riley, J.T.; Ken Ho [Western Kentucky University, Bowling Green, KY (USA). Department of Chemistry

1999-07-01

308

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

International Nuclear Information System (INIS)

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

309

Pyrolysis of brominated feedstock plastic in a fluidised bed reactor  

Energy Technology Data Exchange (ETDEWEB)

Fire retarded high impact polystyrene has been pyrolysed using a fluidised bed reactor with a sand bed. The yield and composition of the products have been investigated in relation to fluidised bed temperature. The bromine distribution between the products and a detailed analysis of the oils using GC-FID/ECD, GC-MS, FT-IR, and size exclusion chromatography has been carried out. It was found that the majority of the bromine transfers to the pyrolysis oil and the antimony was detected in both the oil and the char. Oil made up over 89.9% of the pyrolysis products. Over 30% of the oil consisted of benzene, toluene, ethylbenzene, styrene and cumene. The pyrolysis gases were mainly hydrocarbons in the C{sub 1}-C{sub 4} range but some HBr and Br{sub 2} was detected. (author)

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

2006-08-15

310

Pyrolysis Kinetics of Spent Low-Level Radioactive Resin  

International Nuclear Information System (INIS)

Spent low-level radioactive (LLRA) cation ion exchange resins (consisting of base copolymers of styrene and divinyl benzene and sulfonic acid) are difficult to treat effectively by conventional cement-solidification methods. Pyrolysis of the spent LLRA resin has been recognized to be very effective in reducing the volume and mass of the waste. Experimentally, we found by the thermogravimetric analysis (TGA) method that the activation energy for the pyrolysis of an LLRA resin was 319.2 kJ/mol. The reaction order and pre-exponential factor were 0.61 and 1.1 x 1020 s-1, respectively. Note that during the pyrolysis, ?50% of the SO42- species in the resin was decomposed to SO2 at 673 to 873 K. At high temperatures (>873 K), most of the aromatics of the resin were also thermally cracked

311

Pyrolysis and combustion behaviour of coal-MBM blends.  

Science.gov (United States)

In the present work, thermogravimetric analysis was employed in order to investigate the behaviour of MBM and their blends with Greek brown coal, under pyrolysis and combustion conditions. MBM presented enhanced pyrolysis rates reflecting its high volatile and low ash contents compared to Greek brown coal. Increased conversion rates were observed when MBM was added in the brown coal sample. Significant interactions were detected between the two fuel blend components leading to significant deviations from the expected behaviour. The catalytic effect of mineral matter on the pyrolysis of MBM resulted in reaction rate decrease and DTG curve shift to lower temperatures for the demineralised MBM. Alterations in the combustion process due to the mineral matter were minimal when testing the blends. Interactions maintained during combustion and lower reactivity of MBM was achieved due to the reduced oxygen content. PMID:16442282

Skodras, G; Grammelis, P; Basinas, P

2007-01-01

312

Pyrolysis and combustion behaviour of coal-MBM blends  

Energy Technology Data Exchange (ETDEWEB)

In the present work, thermogravimetric analysis was employed in order to investigate the behaviour of MBM (meat and bone meal) and their blends with Greek brown coal, under pyrolysis and combustion conditions. MBM presented enhanced pyrolysis rates reflecting its high volatile and low ash contents compared to Greek brown coal. Increased conversion rates were observed when MBM was added in the brown coal sample. Significant interactions were detected between the two fuel blend components leading to significant deviations from the expected behaviour. The catalytic effect of mineral matter on the pyrolysis of MBM resulted in reaction rate decrease and DTG curve shift to lower temperatures for the demineralised MBM. Alterations in the combustion process due to the mineral matter were minimal when testing the blends. Interactions maintained during combustion and lower reactivity of MBM was achieved due to the reduced oxygen content.

Skodras, G.; Grammelis, P.; Basinas, P. [Center for Research & Technology Hellas, Ptolemais (Greece)

2007-01-15

313

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

314

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

315

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

316

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

Science.gov (United States)

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

Ganji, Prasad; Ibrahim, Hasim

2012-01-01

317

Microstructure and mechanical properties at high temperature of SiC-matrix by electrophoretic deposition and polymer infiltration and pyrolysis process  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The EFDA-ITER programme for materials wants to develop new structural materials for future nuclear magnetic fusion reactors. In this context, special attention must be paid in the development of new composite materials that could support the hard working conditions of the nuclear fusion reactors: high temperature, high stresses, and high radiation.

Juan Mangas, Teresa; Tejado Garrido, Elena Maria; Ivekovic, Aljaz; Novak, Sasa; Pastor Can?o, Jose Ignacio

2013-01-01

318

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

Energy Technology Data Exchange (ETDEWEB)

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

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

2006-10-30

319

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.

320

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

 
 
 
 
321

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fluorine doped tin oxide, SnO2:F, thin films were deposited by ultrasonic chemical spray starting from tin chloride and hydrofluoric acid. The physical characteristics of the films as a function of both water content in the starting solution and substrate temperature were 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 wi...

Sa?nchez-garci?a, Mario A.; Arturo Maldonado; Luis Castaeda; Rutilo Silva-Gonzlez; Mara de la Luz Olvera

2012-01-01

322

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

323

Fast pyrolysis of lignin, macroalgae and sewage sludge  

Energy Technology Data Exchange (ETDEWEB)

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

Trinh, N.T.

2013-04-15

324

Energy recovery from pyrolysis and gasification of mangrove  

International Nuclear Information System (INIS)

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

325

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

International Nuclear Information System (INIS)

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

326

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

327

Laser induced pyrolysis techniques. [For chemical characterization  

Energy Technology Data Exchange (ETDEWEB)

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

Vanderborgh, N.E.

1976-01-01

328

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

329

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

Science.gov (United States)

This paper proposes a novel energy-efficient oil shale pyrolysis process triggered by a topochemical reaction that can be applied in horizontal oil shale formations. The process starts by feeding preheated air to oil shale to initiate a topochemical reaction and the onset of self-pyrolysis. As the temperature in the virgin oil shale increases (to 250-300C), the hot air can be replaced by ambient-temperature air, allowing heat to be released by internal topochemical reactions to complete the pyrolysis. The propagation of fronts formed in this process, the temperature evolution, and the reaction mechanism of oil shale pyrolysis in porous media are discussed and compared with those in a traditional oxygen-free process. The results show that the self-pyrolysis of oil shale can be achieved with the proposed method without any need for external heat. The results also verify that fractured oil shale may be more suitable for underground retorting. Moreover, the gas and liquid products from this method were characterised, and a highly instrumented experimental device designed specifically for this process is described. This study can serve as a reference for new ideas on oil shale in situ pyrolysis processes. PMID:25656294

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

2015-01-01

330

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)

331

Stabilization of biomass-derived pyrolysis oils  

Energy Technology Data Exchange (ETDEWEB)

Biomass is the only renewable feedstock containing carbon, and therefore the only alternative to fossil-derived crude oil derivatives. However, the main problems concerning the application of biomass for biofuels and bio-based chemicals are related to transport and handling, the limited scale of the conversion process and the competition with the food industry. To overcome such problems, an integral processing route for the conversion of (non-feed) biomass (residues) to transportation fuels is proposed. It includes a pretreatment process by fast pyrolysis, followed by upgrading to produce a crude-oil-like product, and finally co-refining in traditional refineries. This paper contributes to the understanding of pyrolysis oil upgrading. The processes include a thermal treatment step and/or direct hydroprocessing. At temperatures up to 250C (in the presence of H2 and catalyst) parallel reactions take place including re-polymerization (water production), decarboxylation (limited CO2 production) and hydrotreating. Water is produced in small quantities (approx. 10% extra), likely caused by repolymerization. This repolymerization takes place faster (order of minutes) than the hydrotreating reactions (order of tens of minutes, hours). In hydroprocessing of bio-oils, a pathway is followed by which pyrolysis oils are further polymerized if H2 and/or catalyst is absent, eventually to char components, or, with H2/catalyst, to stabilized components that can be further upgraded. Results of the experiments suggest that specifically the cellulose-derived fraction of the oil needs to be transformed first, preferably into alcohols in a 'mild hydrogenation' step. This subsequently allows further dehydration and hydrogenation.

Venderbosch, R.H. [BTG Biomass Technology Group BV, Enschede (Netherlands); Ardiyanti, A.R.; Heeres, H.J.; Wildschut, J. [Rijksuniversiteit Groningen, Groningen, (Netherlands); Oasmaa, A. [VTT, Espoo (Finland)

2010-05-15

332

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

333

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

334

Direct conversion of carbonyl compounds into organic halides: indium(III) hydroxide-catalyzed deoxygenative halogenation using chlorodimethylsilane.  

Science.gov (United States)

The reaction of carbonyls and chlorodimethylsilane was effectively catalyzed by indium(III) hydroxide and afforded the corresponding deoxygenative chlorination products, in which the carbonyl carbon accepted two nucleophiles (H and Cl) with releasing oxygen. Only In(OH)3 catalyzed the reaction, and typical Lewis acids such as TiCl4, AlCl3, and BF3.OEt2 showed no catalytic activity. The reaction mechanism of this deoxygenative chlorination includes initial hydrosilylation followed by chlorination. Other nucleophiles such as allyl or iodine were available for this methodology. The moderate Lewis acidity of indium catalyst enabled chemoselective reaction, and therefore ester, nitro, cyano, or halogen groups were not affected during the reaction course. PMID:12431095

Onishi, Yoshiyuki; Ogawa, Daigo; Yasuda, Makoto; Baba, Akio

2002-11-20

335

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

336

Influence of Pyrolysis Parameters on the Performance of CMSM  

Directory of Open Access Journals (Sweden)

Full Text Available Carbon hollow fiber membranes have been prepared by pyrolysis of a P84/S-PEEK blend. Proximate analysis of the precursor was performed using thermogravimetry (TGA, and a carbon yield of approximately 40% can be obtained. This study aimed at understanding the influence of pyrolysis parametersend temperature, quenching effect, and soaking timeon the membrane properties. Permeation experiments were performed with N2, He, and CO2. Scanning electron microscopy (SEM has been done for all carbon hollow fibers. The highest permeances were obtained for the membrane submitted to an end temperature of 750C and the highest ideal selectivities for an end temperature of 700C. In both cases, the membranes were quenched to room temperature.

Marta C. Campo

2009-01-01

337

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

338

Probing the Thermal Deoxygenation of Graphene Oxide using High Resolution In Situ X-Ray based Spectroscopies  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Despite the recent developments in Graphene Oxide due to its importance as a host precursor of Graphene, the detailed electronic structure and its evolution during the thermal reduction remain largely unknown, hindering its potential applications. We show that a combination of high resolution in situ X-ray photoemission and X-ray absorption spectroscopies offer a powerful approach to monitor the deoxygenation process and comprehensively evaluate the electronic structure of G...

Ganguly, Abhijit; Sharma, Surbhi; Papakonstantinou, Pagona; Hamilton, Jeremy

2011-01-01

339

Nickel-Catalyzed One-Pot Deoxygenation and Reductive Homocoupling of Phenols via C-O Activation Using TCT Reagent.  

Science.gov (United States)

A new method for C-O bond activation of phenolic compounds has been achieved using 2,4,6-trichloro-1,3,5-triazine to utilize in one-pot Ni-catalyzed deoxygenation and reductive homocoupling reactions. With this simple method, phenolic compounds were converted to their corresponding arenes or biaryl compounds under mild conditions. The introduced methodology has a broad scope and demonstrates good functional group compatibility. PMID:25542548

Iranpoor, Nasser; Panahi, Farhad

2015-01-16

340

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

International Nuclear Information System (INIS)

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

 
 
 
 
341

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.

342

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

343

Shock-tube pyrolysis of chlorinated hydrocarbons - Formation of soot  

Science.gov (United States)

Soot formation in pyrolysis of chlorinated methanes, their mixtures with methane, and chlorinated ethylenes were studied behind reflected shock waves by monitoring the attenuation of an He-Ne laser beam. An additional single-pulse shock-tube study was conducted for the pyrolysis of methane, methyl chloride, and dichloromethane. The experiments were performed at temperatures 1300-3000 K, pressures of 0.4-3.6 bar, and total carbon atom concentrations of 1-5 x 10 to the 17th atoms cu cm. The amounts of soot produced in the pyrolysis of chlorinated hydrocarbons are larger than that of their nonchlorinated counterparts. The sooting behavior and product distribution can be generally explained in terms of chlorine-catalyzed chemical reaction mechanisms. The pathway to soot from chlorinated methanes and ethylenes with high H:Cl ratio proceeds via the formation of C2H, C2H2, and C2H3 species. For chlorinated hydrocarbons with low H:Cl ratio, the formation of C2 and its contribution to soot formation at high temperatures becomes significant. There is evidence for the importance of CHCl radical and its reactions in the pyrolysis of dichloromethane.

Frenklach, M.; Hsu, J. P.; Miller, D. L.; Matula, R. A.

1986-01-01

344

Pyrolysis of a waste from the grinding of scrap tyres  

International Nuclear Information System (INIS)

Highlights: ? The pyrolysis of reinforcing fibres obtained from scrap tyres has been studied. ? The results have been compared to scrap tyre granules. ? A higher temperature is needed for the total decomposition of the fibres. ? More compounds with heteroatoms (O, N) were found in the oil from the fibres. ? Chars from the fibres exhibit lower BET surface and mesopore volume. - Abstract: The fibres that are used to reinforce tyres can be recovered as a waste in the process of grinding of scrap tyres. In this paper beneficiation through pyrolysis is studied since the fibres are made up of polymers with a small amount of rubber because the latter is difficult to separate. The experiments were performed at three temperatures (400, 550 and 900 C) in a horizontal oven. The three products gas, oil and char obtained from the pyrolysis were investigated. The composition of the gas was analyzed by means of gas chromatography. The oil was studied by gas chromatography and infrared spectroscopy. The char porous structure was determined by N2 adsorption. In addition, the topography of the chars was studied by means of scanning electron microscopy (SEM). The products resulting from the pyrolysis of the fibres were compared with those obtained from scrap rubber.

345

Pyrolysis of natural gas: Chemistry and process concepts  

Energy Technology Data Exchange (ETDEWEB)

This paper discusses the chemistry and different process concepts of pyrolysis or thermal coupling of natural gas. Methane can be converted directly to C{sub 2} hydrocarbons by pyrolysis or thermal coupling. The reaction is highly endothermic and the heat must be supplied at high temperatures. Ethylene, acetylene, benzene and hydrogen are the main products. Excessive carbon formation can be avoided by using short reaction times and low partial pressures of methane, preferably by hydrogen dilution of the feed. More than 90% selectivity of C{sub 2} hydrocarbons may be obtained from methane. High yields of acetylene (> 85%) are obtainable at extreme conditions of temperatures (> 2000 K) and short reaction times (< 0.01 s). The primary reactions during the pyrolysis of methane are now clearly defined. However, details of the later stages, especially the formation of carbon (coke) are not yet fully understood. The formation of the main gas products can be described by simulation models based on elementary reactions. Pyrolysis of methane has been carried out commercially for many years. The processes differ mainly by the way heat is supplied to the reactor. At present, this technology seems to be an economical way of converting methane only under special conditions where acetylene is the desired product. 70 refs., 9 figs., 1 table

Holmen, A.; Olsvik, O.; Rokstad, O.A.

1996-12-01

346

Thermal stability of thiophene biomarkers as studied by hydrous pyrolysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An immature (Ro = 0.25%) sulphur-rich calcareous shale from the Gessoso-solfifera Formation (Messinian) in the Vena del Gesso Basin (northern Italy) was artificially matured by hydrous pyrolysis at constant temperatures ranging from 160 to 330C for 72 h to study the applicability of alkylthiophenes as molecular indicators during progressive diagenesis and early catagenesis. Artificial maturation at temperatures up to 330C generated large amounts of alkylthiophenes from the thermal degrada...

Sinninghe Damste?, J. S.; Koopmans, M. P.; Lewan, M. D.; Leeuw, J. W.

1995-01-01

347

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

348

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

Energy Technology Data Exchange (ETDEWEB)

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

Shenker, J.

1995-11-01

349

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

International Nuclear Information System (INIS)

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

350

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

351

Exploratory studies on fast pyrolysis oil upgrading  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pyrolysis oil is a dark brown liquid which can be produced in high yield from different kind of biomass sources by means of fast pyrolysis. Pyrolysis oil is considered as a promising second generation energy carrier and may play an important role in the future of "biobased economies". The energy content of pyrolysis oil is approximately half of fossil crude. Just like for crude oil, further reprocessing is necessary to arranged pyrolysis oil as fuel in e.g. combustion engines. This thesis des...

Mahfud, Farchad Husein

2007-01-01

352

CO-PYROLYSIS OF POLYPROPYLENE WITH PETROLEUM OF BACIA DE CAMPOS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, the process of co-pyrolysis of polypropylene (PP) residues with gas-oil was evaluated, varying thetemperature and the amount of polypropylene fed to the reactor. The polypropylene samples and gas-oil weresubmitted to the thermal co-pyrolysis in an inert atmosphere, varying the temperature and the amount of PP.The influence of the gas-oil was evaluated carrying the co-pyrolysis in the absence of PP. The pyrolysed liquidsproduced by this thermal treatment were characterized by mo...

Assumpc?a?o, Luiz Carlos Fonte Nova Marques

2009-01-01

353

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

354

Fluidized bed selective pyrolysis of coal  

Science.gov (United States)

The present invention discloses a process for the pyrolysis of coal which comprises the effective utilization of two zonal inclined fluidized beds, where said zones can be selectively controlled as to temperature and heating rate. The first zonal inclined fluidized bed serves as a dryer for crushed coal and additionally is controlled to selectively pyrolyze said coal producing substantially carbon dioxide for recycle use. The second zonal inclined fluidized bed further pyrolyzes the coal to gaseous, liquid and char products under controlled temperature and heating rate zones designed to economically integrate the product mix. The gas and liquid products are recovered from the gaseous effluent stream while the char which remains can be further treated or utilized in a subsequent process step.

Shang, Jer Y. (McLean, VA); Cha, Chang Y. (Golden, CO); Merriam, Norman W. (Laramie, WY)

1992-01-01

355

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

356

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

357

UVC emitting phosphors obtained by spray pyrolysis  

Energy Technology Data Exchange (ETDEWEB)

The broadband inter-configurational (4f{sup 1}5d{sup 1{yields}}4f{sup 2}) emission of Pr{sup 3+} doped in lanthanum orthophosphate (LaPO{sub 4}) and in calcium pyrophosphate (Ca{sub 2}P{sub 2}O{sub 7}) has been investigated under plasma excitation. The synthesis by spray pyrolysis at moderate temperature followed by a controlled annealing proves to be a very efficient way to produce good quality UVC emitting phosphor Ca{sub 1.92}Pr{sub 0.04}Na{sub 0.04}P{sub 2}O{sub 7} ({alpha} phase). The emission of this phosphor in the wavelength range 200-350 nm has been measured with a prototype device, which can be employed for anti-microbial testing. - Research Highlights: {yields} The Pr{sup 3+} doped orthophosphate and pyrophosphate were synthesized by spray pyrolysis. {yields} The dense particles present good quality UVC emitting (200-350 nm). {yields} The prototype device can be employed for anti-microbial testing.

Caiut, J.M.A., E-mail: jmacaiut@iq.unesp.b [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CEMES/CNRS-BP 94347, 31055 Toulouse Cedex 4 (France); Institute of Chemistry, UNESP-Universidade Estadual Paulista, CP 355, Araraquara-SP 14801-970 (Brazil); Lechevallier, S.; Dexpert-Ghys, J. [Centre d' Elaboration de Materiaux et d' Etudes Structurales, CEMES/CNRS-BP 94347, 31055 Toulouse Cedex 4 (France); Caillier, B.; Guillot, Ph. [Diagnostic des Plasmas Hors Equilibre, Universite Jean Francois Champollion, place de Verdun, 81012 Albi Cedex 9 (France)

2011-04-15

358

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

359

Pure 2D vortex-glass phase transition with Tg=0 K in deoxygenated YBa2Cu3O6.4 thin films  

International Nuclear Information System (INIS)

Non-linear I-V characteristics have been measured on high-quality deoxygenated YBa2Cu3O6.4 thin films, in magnetic fields up to 8 T. Critical scaling analysis of the current-voltage data demonstrates the existence of a pure two-dimensional vortex-glass transition with Tg = 0 for high magnetic fields (7, 8 T). The validity of the pure 2D vortex-glass model in our samples is checked with the linear resistivity term and the non-linear current density. The linear resistivity ?lin(T)?exp[-(T0/T)p] from resistivity vs. temperature and current-voltage measurements, produces the parameters p (p = 0.78 for H = 7 T, p = 0.73 for H = 8 T) and T0 (230 K) used for the scaling analysis. The non-linear current density jnl exhibits a power law temperature dependence jnl(T)?T3 suggesting ?2D = 2 as predicted by the 2D vortex-glass theory. The values of the exponent p obtained in this study are in good agreement with the (orig.)

360

Bio-oil production through pyrolysis of blue-green algae blooms (BGAB): Product distribution and bio-oil characterization  

International Nuclear Information System (INIS)

Pyrolysis experiments of blue-green algae blooms (BGAB) were carried out in a fixed-bed reactor to determine the effects of pyrolysis temperature, particle size and sweep gas flow rate on pyrolysis product yields and bio-oil properties. The pyrolysis temperature, particle size and sweep gas flow rate were varied in the ranges of 300700 C, below 0.252.5 mm and 50400 mL min?1, respectively. The maximum oil yield of 54.97% was obtained at a pyrolysis temperature of 500 C, particle size below 0.25 mm and sweep gas flow rate of 100 mL min?1. The elemental analysis and calorific value of the oil were determined, and the chemical composition of the oil was investigated using gas chromatographymass spectroscopy (GCMS) technique. The analysis of bio-oil composition showed that bio-oil from BGAB could be a potential source of renewable fuel with a heating value of 31.9 MJ kg?1. - Highlights: ? Bio-oil production from pyrolysis of blue-green algae blooms in fixed bed reactor. ? Effects of pyrolysis conditions on product distribution were investigated. ? The maximum bio-oil yield reached 54.97 wt %. ? The bio-oil has high heating value and may be suitable as renewable fuel. ? Pyrolysis of algal biomass beneficial for energy recovery, eutrophication control

 
 
 
 
361

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

Science.gov (United States)

In this study, biomass pyrolysis process for producing H(2)-rich gas is presented. The whole biomass pyrolysis process is established and simulated based on rigorous thermodynamic model, which includes pyrolysis reactor connecting one oil cracking reactor, water gas reactor and a gasifier. The simulation results are verified by the laboratory scale experimental measurements. Then, the influence of main operation parameters such as seam/biomass ratio, temperature (pyrolysis reactor, oil thermal cracking and gasifier) on the composition of fuel gas and hydrogen yield is discussed. Lastly, the optimization results are available. The results indicate that higher gas products and hydrogen yield can be obtained from the process, the H(2) yield can reach 83g/kg biomass, the H(2) concentration can reach 55% (mol) at the optimal temperature and steam/biomass ratio. PMID:19523817

Li, Chunshan; Suzuki, Kenzi

2010-01-01

362

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

International Nuclear Information System (INIS)

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

363

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

364

Virulence prediction of Yersinia enterocolitica by pyrolysis gas-liquid chromatography.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pyrolysis gas-liquid chromatography (PGLC) was used to differentiate between HeLa cell-invasive and noninvasive strains of Yersinia enterocolitica and between Sereny-positive and -negative strains. A temperature-programmed gas-liquid chromatograph, equipped with a high-resolution Carbowax 20M coated capillary column, separated the volatiles from pyrolyzed whole cells preparations and cell wall fractions. The resulting pyrolysis elution patterns (pyrograms) were divided into 313 30-s time inte...

Stern, N. J.; Kotula, A. W.; Pierson, M. D.

1980-01-01

365

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

366

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

367

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

368

Thermogravimetric characterization of dairy manure as pyrolysis and combustion feedstocks.  

Science.gov (United States)

Thermogravimetric analysis was used to examine the thermal behavior of dairy manure as a pyrolysis and combustion feedstock. Nitrogen and air were used as purging gases to analyze the pyrolysis and combustion reactions, respectively, and heating rates of 20C min(-1), 40C min(-1) and 60C min(-1) were applied. An Arrhenius model was used to estimate the kinetic parameters (activation energy, reaction order and pre-exponential factor). Results showed four steps for both the pyrolysis and the combustion reactions, with the second step being the most critical one and during which most thermal decomposition of cellulose, hemicelluloses, starch and protein occurred. Thermochemical reactions were determined mainly by temperature. Heating rate influenced the start and the end of the thermal conversions. The activation energies for the two major reaction zones were 93.63 kJ mol(-1) and 84.53 kJ mol(-1) for pyrolysis, and 83.03 kJ mol(-1) and 55.65 kJ mol(-1) for combustion. Knowledge of the thermal behavior of dairy manure provides guidelines for future energy utilization. PMID:22767875

Wu, Hanjing; Hanna, Milford A; Jones, David D

2012-10-01

369

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

370

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

371

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

372

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

373

Construction of a Labview controlled pyrolysis unit for coupling to a Pyrola 85 pyrolysis chamber  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pyrolysis is the process of molecular decomposition in an inert environment using heat. It is possible to fragment large molecules, such as polymers, by pyrolysis and separate the fragments directly in a GC. This makes it possible to form complex sample fingerprints that can be used in various applications, for example in forensic science. In this project, a malfunctioning Pyrola 85 pyrolysis unit was fixed by measuring the voltage signals from the photo diode during pyrolysis in a Labview pr...

O?stman, Marcus; Na?sstro?m, Elin

2012-01-01

374

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

375

Parameters for the Pyrolysis of Organic Material - Perchlorate Mixtures  

Science.gov (United States)

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

Steininger, Harald; Goesmann, Fred; Goetz, Walter

2013-04-01

376

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

377

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 d 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.

378

N-amino heterocycles : applications in flash vacuum pyrolysis  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Routes to N-amino heterocycles were reviewed and findings applied to generate flash vacuum pyrolysis (FVP) precursors of two types - ketene generators and azol-1-yl radical generators. N-Amino heterocycles can be used as nitrogen radical generators, the N-N bond being homolytically cleaved at furnace temperatures of approximately 850 C. A number of 2-substituted benzimidazoles were synthesised and subsequently Naminated. The 2-arylbenzimidazole precursors 1-amino-2-(2-meth...

Rozgowska, Emma Jayne

2011-01-01

379

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

380

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-07-01

 
 
 
 
381

Validation of the integral model for the pyrolysis of charring materials with a moving grid  

Science.gov (United States)

For the pyrolysis of charring materials a new one dimensional moving grid model is developed. The solid is divided by a pyrolysis front into a char and a virgin layer. Only when the virgin material reaches a critical temperature it starts to pyrolyse. The progress of the pyrolysis front determines the release of combustible volatiles. Since the model is used here as a stand-alone model, the external heat flux that heats up the solid, is assumed to be known. The char and virgin grid move along with the pyrolysis front. Calculations are done on uniform and nonuniform grids for the virgin layer. In the char layer only a uniform grid is used. Calculations done with a non-uniform grid are about 3 times faster than with a uniform grid. The moving grid model is used to validate the approximate integral model. This revealed that the integral model gives significant errors when there are sudden changes in the boundary conditions.

Theuns, E.; Vierendeels, J.; Vandevelde, P.

2004-07-01