Showing papers on "Pyrolysis published in 2006"
TL;DR: In this article, the different roles of the three components (hemicellulose, cellulose, and lignin) in pyrolysis are investigated in depth using a thermogravimetric analyzer (TGA).
Abstract: To better understand biomass pyrolysis, the different roles of the three components (hemicellulose, cellulose, and lignin) in pyrolysis are investigated in depth using a thermogravimetric analyzer (TGA). The pyrolysis characteristics of the three components are first analyzed, and the process of biomass pyrolysis is divided into four ranges according to the temperatures specified by individual components. Second, synthesized biomass samples containing two or three of the biomass components are developed on the basis of a simplex-lattice approach. The pyrolysis of the synthesized samples indicates negligible interaction among the three components and a linear relationship occurring between the weight loss and proportion of hemicellulose (or cellulose) and residues at the specified temperature ranges. Finally, two sets of multiple linear-regression equations are established for predicting the component proportions in a biomass and the weight loss of a biomass during pyrolysis in TGA, respectively. The resul...
1,000 citations
TL;DR: The most active catalysts were formed when Fe was added to the support before the pyrolysis; however, samples in which Ni or no metal was added still showed increased activity for oxygen reduction compared with untreated carbon as mentioned in this paper.
849 citations
TL;DR: In this article, the authors used FT-Raman spectroscopy with a 1064nm laser to investigate chemical structural changes of char during pyrolysis of brown coal samples.
740 citations
TL;DR: In this paper, the effect of process parameters such as pyrolysis temperature, heating rate and holding time on the yields of pyrotechnic products and their chemical compositions were investigated.
411 citations
TL;DR: In this paper, a systematic and comparative evaluation of the pyrolysis of halogen-free flame-retarded epoxy resins containing phosphine oxide, phosphinate, phosphonate, and phosphate (phosphorus contents around 2.6 wt%) and the fire behavior of their carbon fiber composites is presented.
379 citations
TL;DR: Microwave pyrolysis still preserved some of the functional groups of the initial sludge such as aliphatic and oxygenated compounds, whereas no heavy PACs were detected.
347 citations
TL;DR: In this paper, the authors investigated the reasons for the increased durability of heat-treated beech wood compared to other types of wood and found a good correlation between decay resistance and mass loss measurements which are directly correlated to hemicellulose degradation.
315 citations
TL;DR: In this article, activated carbons have been prepared from woody biomass birch by using various activation procedures: treatment with phosphoric acid and pyrolysis at 600 degrees C in inert atmosphere.
298 citations
TL;DR: In this article, the co-pyrolytic behavior of plastic/biomass mixtures was investigated using a thermogravimetric analyser under a heating rate of 20°C/min from room temperature to 650°C, where the difference of weight loss (Δ W ) between experimental and theoretical ones, calculated as algebraic sums of those from each separated component, is about 6-12% at 530-650°C.
292 citations
TL;DR: In this article, the mesopores of MCM-41 materials have been evaluated as potential catalysts in the catalytic biomass pyrolysis process and it was found that the presence of the MCM41 material alters significantly the quality of the pyrotechnic products.
292 citations
TL;DR: In this paper, the FTIR spectra of untreated date pits and their H3PO4-preimpregnated sample together with their chars as well as samples subjected to different activation schemes were determined.
TL;DR: In this article, coal chars were produced by rapid pyrolysis of pulverized bituminous coals using a DTF with a nitrogen gas flow at 1670 K. Gasification rate equations and kinetic parameters applicable to a pore diffusion zone at high temperature were obtained for each coal.
TL;DR: In situ catalytic upgrading of biomass derived fast pyrolysis vapours in a fixed bed reactor using mesoporous materials is described in this article, where a fixed-bed reactor is used.
TL;DR: In this article, the pyrolysis of waste sludges was investigated using thermogravimetry/mass spectrometry (TG/MS) and a fixed-bed reactor.
TL;DR: In this article, Fe-based catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) were obtained by adsorbing 0.2 wt % Fe from iron acetate on each carbon support, which is then pyrolyzed at 900°C for 1 h in a NH 4 /H 2 /Ar mixture.
Abstract: Fe-based catalysts for the oxygen reduction reaction (ORR) in polymer electrolyte membrane fuel cells (PEMFCs) have been prepared with commercial and developmental carbon black powders containing initially between 0 and 0.8 atom % of nitrogen. The catalysts were obtained by adsorbing 0.2 wt % Fe from iron acetate on each carbon support, which is then pyrolyzed at 900°C for 1 h in a NH 4 /H 2 /Ar mixture. Under these conditions, N contents from 0 to 2.3 atom % are measured at the surface of the catalysts and increased N content leads to increased activity for the ORR. The N content correlates with the weight loss of the carbon support due to a reaction with NH 3 during pyrolysis. It was found that NH 3 reacts mainly with the disorganized carbon, leaving nitrogen at the surface of the support. The larger the amount of disorganized carbon in the pristine carbon black, the better the activity for ORR of the resulting catalyst. The most active non-noble catalyst was tested in fuel cells, where it was found that its specific activity (in A per cm 3 of electrode) is still about two orders of magnitude below the target of a non-noble catalyst for automotive applications. However, such catalysts could already compete with Pt in, e.g., methanol fuel cells because they are ORR-selective.
TL;DR: In this article, the authors used transient and steady-state techniques to study the reaction network of acetic acid under steam reforming conditions over Al 2O3 and La2O3, and Ni catalyst supported on La 2 O3/Al 2 O 3 carrier and found that carbon formation is affected by reaction temperature, the HAc/H2O ratio and catalyst composition.
Abstract: Catalytic steam reforming of bio-oil, a liquid derived from pyrolysis of biomass, may be a viable process of renewable hydrogen production. Acetic acid is one of the major constituents of bio-oil, and for this reason, it is used as a model compound to study its reaction network under steam reforming conditions over Al2O3 and La2O3, and Ni catalyst supported on La2O3/Al2O3 carrier, employing transient and steady-state techniques. It is found that acetic acid interacts strongly with the Al2O3 carrier and less strongly with La2O3. Decomposition reactions as well as the ketonization reaction take place, especially at intermediate temperatures. In the presence of Ni, catalytic activity is shifted toward lower temperatures. Nickel promotes steam reforming reactions and retards the rate of carbon deposition onto the catalyst surface. It is also found that carbon formation is affected by reaction temperature, the HAc/H2O ratio and catalyst composition. Carbon deposition is favoured at low reaction temperatures and at high HAc/H2O ratio.
TL;DR: In this paper, the effects of oxygen concentration on TGA of wood and evolved gas analysis were thoroughly analyzed, and then the process of pyrolysis and combustion of wood was divided into four steps.
TL;DR: In this paper, an activity test of Ni/CeO2 and Ni/MgO catalysts in the partial oxidation (POT) and steam reforming of tar (SRT) derived from the pyrolysis of cedar wood was performed.
TL;DR: In wood combustion, inorganic elements such as alkali metals, sulfur, chlorine, and some heavy metals are partly released to the gas phase, which may cause problems in combustion facilities as mentioned in this paper.
Abstract: During wood combustion, inorganic elements such as alkali metals, sulfur, chlorine, and some heavy metals are partly released to the gas phase, which may cause problems in combustion facilities bec...
TL;DR: In this article, the impact of the pyrolysis heating rate both on the properties of the residual charcoal and on the behaviour during gasification by H 2 O of the charcoal was quantified.
TL;DR: The chemical characterization showed that the bio-oil obtained from olive bagasse may be potentially valuable as a fuel and chemical feedstock.
TL;DR: In this paper, three kinds of apricot stones that differ in their sulfur content, because of different drying processes, were chosen for the study to investigate the effect of sulfur in the activated carbon production.
13 Dec 2006
TL;DR: Analytical pyrolysis - an overview instrumentation and analysis pyrolysis mass spectrometry - instrumentation, techniques, and applications microstructure of polyolefins degradation mechanisms of condensation polymers.
Abstract: Analytical pyrolysis - an overview instrumentation and analysis pyrolysis mass spectrometry - instrumentation, techniques, and applications microstructure of polyolefins degradation mechanisms of condensation polymers the application of analytical pyrolysis to the study of cultural materials environmental applications of pyrolysis examination of forensic evidence characterization of micro organisms by pyrolysis-GC, pyrolysis-GC/MS and pyrolysis-MS analysis of polar macromolecules index of sample pyrograms.
TL;DR: In this paper, a free-fall pyrolysis of four kinds of biomass (legume straw, tobacco stalk, pine sawdust and apricot stone) was conducted in a free fall reactor.
TL;DR: In this paper, the optimum reaction conditions of the formation of multi-wall carbon nanotubes (MWCNTs) can be obtained by using a 50mg of nano-MgNi alloy under pyrolysis of the pure CH 4 gas with the flow rate about 100-120 cm 3 /min at 650°C for 30min.
TL;DR: In this article, the influence of the operating pyrolysis parameters on the activated carbon was investigated in particular, and the optimum conditions were a temperature of 600°C, hold time of 2h, nitrogen flow rate of 150 cm 3 /min and heating rate of 10°C/min.
TL;DR: Analysis of the nitrogen-doped carbon preparation process, characterization of the carbon materials formed, and activity testing for the ORR showed evidence that differences in the nanostructure and surface functional groups of the samples are likely to account for observed differences in oxygen reduction activity.
Abstract: Noble-metal-free active catalysts for the oxygen reduction reaction (ORR) in an acidic environment were prepared from the pyrolysis of acetonitrile at 900 °C over alumina and metal-doped alumina. This work includes analyses of the nitrogen-doped carbon preparation process, characterization of the carbon materials formed, and activity testing for the ORR. The nitrogen-containing carbon nanostructures that formed during the pyrolysis of acetonitrile could be purified by washing the product with hydrofluoric acid. A wide range of techniques were used to characterize the solid carbon products of the acetonitrile decomposition. While the samples have many similar physical properties, X-ray photoelectron spectroscopy and transmission electron microscopy showed evidence that differences in the nanostructure and surface functional groups of the samples are likely to account for observed differences in oxygen reduction activity. The most active catalysts were prepared over alumina impregnated with up to 2 wt % Fe,...
TL;DR: In this article, structural properties of microcrystalline LiFePO4 with and without carbon coating are analyzed with X-ray diffraction spectroscopy, Fourier transform infrared spectrographs, Raman spectrograms, and magnetic measurements for comparison.
Abstract: The structural properties of microcrystalline LiFePO4 prepared with and without carbon coating are analyzed with X-ray diffraction spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, and magnetic measurements for comparison. While nanosized ferromagnetic particles (-Fe2O3 clusters) are evidenced from magnetic measurements in samples without carbon coating, such ferromagnetic clusters just do not exist in the carbon-coated sample. Ferromagnetic resonance experiments are a probe of the -Fe2O3 nanoparticles, and magnetization measurements as well, allowing for a quantitative estimate of the amount of Fe3+. While the fraction of iron in the Fe3+ configuration rises to 0.18% (in the form of -Fe2O3 nanoparticles) in the carbon-free sample, this fraction falls to a residual impurity concentration in the carbon-coated sample. Structural properties show that the carbon does not penetrate inside the LiFePO4 particles but has been very efficient in the reduction of Fe3+, preventing the -Fe2O3 clustering thus pointing out a gas phase reduction process. The carbon deposit characterized by Raman spectroscopy is an amorphous graphite deposit hydrogenated with a very small H/C ratio, with the same Raman characteristics as a-C carbon films obtained by pyrolysis technique at pyrolysis temperature 830±30°C. The impact of the carbon coating on the electrochemical properties is also reported.
TL;DR: In this paper, the synthesis of porous graphitic carbon with a large and accessible surface area via synthesis of carboxyl-containing polymer particles, followed by ion exchange and pyrolysis at low temperature (850 °C).
Abstract: High surface area graphitic carbons are of great interest in emerging applications including catalysis and energy storage because of the well-developed crystalline structure, high electronic conductivity and thermal stability, and satisfactory oxidation resistance at low temperature. We have developed the synthesis of porous graphitic carbon with a large and accessible surface area via synthesis of carboxyl-containing polymer particles, followed by ion exchange and pyrolysis at low temperature (850 °C). The evolution of the graphitic structure together with mesoporosity is temperature dependent, as revealed from the results of X-ray diffraction, transmission electron microscopy, and nitrogen sorption measurement. Specifically, the development of mesoporosity resulting from continuously catalyzed carbonization by the in situ formed cobalt nanoparticles can be clearly recognized. Further nitric acid oxidation leads to an increase of the pore volume due to the removal of cobalt nanoparticles and opening of c...
TL;DR: Sonodynamic therapy appears to be a promising modality for cancer treatment since ultrasound can penetrate deep within the tissue and can be focused in a small region of tumor to chemically activate relatively non‐toxic molecules thus minimizing undesirable side effects.
Abstract: Current understanding of the mechanism of sonodynamic action (i.e. the ultrasound-dependent enhancement of the cytotoxic action of certain drugs--sonosensitizers) with potential applications for cancer therapy is presented. The experimental evidence suggests that sonosensitization is due to the chemical activation of sonosensitizers inside or in the close vicinity of hot collapsing cavitation bubbles to form sensitizer-derived free radicals either by direct pyrolysis or due to reactions with .H and .OH radicals, formed by pyrolysis of water. These free radicals (mostly carbon-centered) react with oxygen to form peroxyl and alkoxyl radicals. Unlike .OH and .H, which are also formed by pyrolysis inside cavitation bubbles, the reactivity of alkoxyl and peroxyl radicals with organic components dissolved in biological media is lower and hence have higher probability of reaching critical cellular sites. Sonodynamic therapy appears to be a promising modality for cancer treatment since ultrasound can penetrate deep within the tissue and can be focused in a small region of tumor to chemically activate relatively non-toxic molecules (e.g. porphyrins) thus minimizing undesirable side effects.