Showing papers on "Pyrolysis published in 2002"
TL;DR: The pyrolysis process is degradation of biomass by heat in the absence of oxygen, which results in the production of charcoal, liquid, and gaseous products as mentioned in this paper.
Abstract: The pyrolysis is degradation of biomass by heat in the absence of oxygen, which results in the production of charcoal, liquid, and gaseous products The pyrolysis process can be divided into three subclasses: conventional pyrolysis, fast pyrolysis, and flash pyrolysis The hemicelluloses break down first at temperatures of 470 to 530 K, cellulose follows in the temperature range 510 to 620 K, and lignin is the last component to pyrolyze at temperatures of 550 to 770 K If the purpose is to maximize the yield of liquid products resulting from biomass pyrolysis, a low temperature, high heating rate, short gas residence time process would be required For a high char production, a low temperature, low heating rate process would be chosen If the purpose was to maximize the yield of fuel gas resulting from pyrolysis, a high temperature, low heating rate, long gas residence time process would be preferred
649 citations
TL;DR: In this article, the change of mass and composition of biomass tar due to homogeneous secondary reactions was experimentally studied by means of a lab reactor system that allows the spatially separated production and conversion of the biomass tar.
507 citations
TL;DR: In this article, a thermogravimetric analyzer coupled with a differential scanning calorimeter (DSC) and mass spectrometer (MS) was used to pyrolyze materials such as cellulose, pectin, and xylan.
473 citations
TL;DR: In this paper, date pits, a low-cost agricultural byproduct, was tested as a precursor for the production of porous carbons in a chemical scheme using phosphoric acid.
386 citations
TL;DR: In this paper, the effect of the process conditions such as heating rate, temperature and particle size on the product distribution, gas composition and char reactivity was studied in a free-fall reactor at pilot scale.
Abstract: This paper deals with rapid pyrolysis of agricultural residues such as olive waste and straw at high temperature (800 -1000degreesC) in a free-fall reactor at pilot scale. The conditions are of interest for gasification in fluidized beds where rapid pyrolysis plays an important role as first stage. The objective of the work is to study the effect of the process conditions such as heating rate, temperature and particle size on the product distribution, gas composition and char reactivity. A higher temperature and smaller particles increase the heating rate resulting in a decreased char yield. The cracking of the hydrocarbons with an increase in the hydrogen content is favoured by a higher temperature and by using smaller particles. Wood gives more volatiles and less char than straw and olive waste. The higher ash content in agricultural residues favours the charring reactions. The higher lignin content in olive waste results in a higher char yield in comparison with straw. Chars from olive waste and straw are more reactive in gasification than chars from birch because of the higher ash content.
377 citations
TL;DR: In this article, the pyrolysis of a sewage sludge, produced by a Spanish urban wastewater treatment plant, was carried out in a laboratory furnace, and the effects of pyrolyses on the characteristics of the resulting gases, liquids and solid residues could be studied.
361 citations
TL;DR: In this article, an approach for biomass flash pyrolysis in a circulating fluid bed (CFB) reactor with continuous solids regeneration is described, which is capable of performing both conventional and catalytic biomass pyrotechnics with the proper solid selection.
346 citations
TL;DR: In this paper, pyrolysis-GC/MS/C-IRMS was performed on maize plants and on two samples from the same soil that had undergone a vegetation change from the C3 plant wheat to the C4 plant maize.
330 citations
TL;DR: In this paper, two coal chars were gasified with carbon dioxide or steam using a Pressurized Drop Tube Furnace (PDTF) at high temperature and pressurized conditions to simulate the inside of an air-blown two-stage entrained flow coal gasifier.
315 citations
TL;DR: In this article, the influence of zeolite catalytic upgrading of pyrolysis gases derived from polyethylene has been investigated in terms of the temperature of the catalyst and the yield and composition of derived hydrocarbon gases and oils.
301 citations
TL;DR: This paper describes a new method for pyrolyzing sewage sludge using a microwave furnace, found that if just the raw wet sludge is treated in the microwave, only drying of the sample takes place, but if it is mixed with a small amount of a suitable microwave absorber, temperatures of up to 900 degrees C can be achieved, so thatpyrolysis takes place rather than drying.
TL;DR: In this article, a set of brown coal samples was pyrolysed in a thermogravimetric analyser and in a novel fluidised-bed/fixed-bed reactor.
TL;DR: In this article, the authors characterized charring of a softwood and hardwood and found that the wood was dominated by (di)- O -alkyl structures, and the chars by alkyl and aromatic structures.
TL;DR: In this article, the influence of different washing techniques on the alkali release during pyrolysis of biomass is studied, and the results support the conclusion from earlier studies that relatively simple washing techniques can improve the combustion properties of biomass fuels with a high ash content.
TL;DR: In this article, powdery peanuts were treated by one-step procedures to get activated carbon using chemical activation by H3PO4, ZnCl2, KOH and thermal activation by steam pyrolysis.
TL;DR: In this article, three different biomass samples were subjected to direct and catalytic pyrolysis to obtain hydrogen rich gaseous products at desired temperatures, both untreated and impregnated with catalyst.
TL;DR: In this paper, the thermal behavior of wood biomass and synthetic polymer mixtures was studied in a rotating autoclave and the effects of reaction conditions, biomass and polymers origins on the degree of mixture conversion as well as on the yields of liquid and gaseous products were established and discussed.
TL;DR: In this article, a general model of the pyrolysis of a wood slab is presented and validated with a set of heat release data, applied to particle half-thicknesses from 5 μm to 5 cm, temperatures from 800 to 2000 K, and moisture contents from 0% to 30%.
Abstract: A general model of the pyrolysis of a wood slab is presented and validated with a set of heat release data. The model is applied to particle half-thicknesses from 5 μm to 5 cm , temperatures from 800 to 2000 K , and moisture contents from 0% to 30%. Internal temperatures, pyrolysis rates and yields of tar, hydrocarbons and char are presented. Four pyrolysis regimes are identified, depending on external temperature and particle size: thermally thin—kinetically limited, thermally thin—heat transfer limited, thermally thick, and thermal wave regimes.
TL;DR: In this article, two processes, thermal treatment and oxidation, were separated for a fundamental study of structural evolution during pyrolysis and combustion, as well as for the study of the influence of such evolution on char reactivity.
TL;DR: Preorganization of the carbon precursor through self-assembly in block copolymers of polyacrylonitrile appears to be an attractive and robust strategy for templated synthesis of well-defined nanostructured carbon materials.
Abstract: Arrays of graphitic carbon nanoclusters were obtained by pyrolysis of nanoscale phase-separated block copolymers of polyacrylonitrile and poly(n-butyl acrylate). Upon heating in an inert atmosphere to temperatures ranging from approximately 400 to 1200 degrees C, polyacrylonitrile domains were converted into carbon nanoclusters, maintaining the overall shape and spacing, whereas the poly(n-butyl acrylate) phase was sacrificed. Preservation of the original nanoscale morphology of a block copolymer was possible only if pyrolysis was preceded by oxidation at temperatures of approximately 230 degrees C, in analogy with thermal stabilization of polyacrylonitrile precursor in the process used in the manufacturing of carbon fibers. Preorganization of the carbon precursor through self-assembly in block copolymers of polyacrylonitrile appears to be an attractive and robust strategy for templated synthesis of well-defined nanostructured carbon materials.
TL;DR: In this article, the sugarcane bagasse vacuum pyrolysis was performed at both a laboratory and a pilot plant scale and the results indicated that the bio-oil has a thermal susceptibility similar to oils obtained from other biomass materials.
TL;DR: In this article, the authors studied the chemical durability of silicon oxycarbide (SiOC) glasses in both alkaline and hydrofluoric solutions and related to the network structure and microstructure of the glasses.
Abstract: Silicon oxycarbide (SiOC) glasses with controlled amounts of Si-C bonds and free carbon have been produced via the pyrolysis of suitable preceramic networks. Their chemical durability in alkaline and hydrofluoric solutions has been studied and related to the network structure and microstructure of the glasses. SiOC glasses, because of the character of the Si-C bonds, exhibit greater chemical durability in both environments, compared with silica glass. Microphase separation into silicon carbide (SiC), silica (SiO 2 ), and carbon, which usually occurs in this system at pyrolysis temperatures of >1000-1200°C, exerts great influence on the durability of these glasses. The chemical durability decreases as the amount of phase separation increases, because the silica/silicate species (without any carbon substituents) are interconnected and can be easily leached out, in comparison with the SiOC phase, which is resistant to attack by OH - or F - ions.
TL;DR: In this paper, the pyrolysis of HDPE in a fluidized bed reactor was performed and the influence of the temperature and the residence time on the product distribution and gas composition was investigated.
TL;DR: The results indicated that the activated carbon made from sewage sludge had remarkable micropore and mesopore surface areas and notable adsorption capacities for phenol and carbon-tetrachloride in comparison with commercial activated carbons.
TL;DR: In this paper, the authors compared the performance of two pyrolysis methods, i.e., isothermal linear regression and non-isothermal nonlinear regression, and showed that there is no correlation between the two methods.
TL;DR: In this paper, coal, CaO and CO reactions with steam, and CO2 absorption by Ca(OH)2 or CaO occurred simultaneously in the experiment and it was found that H2 was the primary resultant gas, comprising about 85% of the reaction products.
TL;DR: In this paper, a fixed-bed slow pyrolysis experiment was conducted on a sample of safflower seed to determine particularly the effects of pyrolysis temperature, heating rate, particle size and sweep gas flow rate on the product yields and their chemical compositions.
TL;DR: In this article, the authors demonstrate the possibility to synthesize mixed carbon aerogels (denoted CmRF) from cresol (Cm), resorcinol (R), and formaldehyde (F), as an alternative economic route to the classical RF synthesis.
TL;DR: In this paper, it was shown that the chemical and physical form of sodium in brown coal is an important factor influencing the volatilisation of sodium during pyrolysis.
TL;DR: In this article, carbon cryogel microspheres were successfully synthesized by an inverse emulsion polymerization of resorcinol with formaldehyde, followed by freeze drying and pyrolysis in an inert atmosphere.