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Rotary kiln pyrolysis of straw and fermentation residues in a 3MW pilot plant – Influence of pyrolysis temperature on pyrolysis product performance
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Stefan Kern, Michael Halwachs, Gerhard Kampichler, Christoph Pfeifer, Tobias Pröll, Hermann Hofbauer
The idea of co-firing biomass in an already existing coal-fired power plant could play a major contribution in the reduction of carbon dioxide emissions. Huge amounts of unused biomass in terms of agricultural residues such as straw, which is a cheap and local feedstock, are often available. But due to the high amount of corrosive ash elements (K, Cl, etc.), the residues are usually not suitable for co-firing in a thermal power plant. Therefore, the feedstock is converted by low temperature pyrolysis into gaseous pyrolysis products and charcoal. A 3MW pyrolysis pilot plant located next to a coal-fired power plant near Vienna was set up in 2008. For the process, an externally heated rotary kiln reactor with a design fuel power of 3MW is used which can handle about 0.6–0.8t/h straw. The aim is to investigate the fundamentals for scale-up to the desired size for co-firing in a coal-fired power plant. In addition to the desired fuel for the process, which is wheat straw, a testing series for DDGS was also performed. The high amount of pyrolysis oil in the gas had positive effects on the heating value of the pyrolysis gas. Chemical efficiencies of this pyrolysis pilot plant of up to 67% for pyrolysis temperatures between 450°C and 600°C can be reached. The focus of this work is set on the pyrolysis products and their behavior at different pyrolysis temperatures as well as the performance of the pyrolysis process.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Stefan Kern, Michael Halwachs, Gerhard Kampichler, Christoph Pfeifer, Tobias Pröll, Hermann Hofbauer
The idea of co-firing biomass in an already existing coal-fired power plant could play a major contribution in the reduction of carbon dioxide emissions. Huge amounts of unused biomass in terms of agricultural residues such as straw, which is a cheap and local feedstock, are often available. But due to the high amount of corrosive ash elements (K, Cl, etc.), the residues are usually not suitable for co-firing in a thermal power plant. Therefore, the feedstock is converted by low temperature pyrolysis into gaseous pyrolysis products and charcoal. A 3MW pyrolysis pilot plant located next to a coal-fired power plant near Vienna was set up in 2008. For the process, an externally heated rotary kiln reactor with a design fuel power of 3MW is used which can handle about 0.6–0.8t/h straw. The aim is to investigate the fundamentals for scale-up to the desired size for co-firing in a coal-fired power plant. In addition to the desired fuel for the process, which is wheat straw, a testing series for DDGS was also performed. The high amount of pyrolysis oil in the gas had positive effects on the heating value of the pyrolysis gas. Chemical efficiencies of this pyrolysis pilot plant of up to 67% for pyrolysis temperatures between 450°C and 600°C can be reached. The focus of this work is set on the pyrolysis products and their behavior at different pyrolysis temperatures as well as the performance of the pyrolysis process.
Highlights
► Experimental study in low temperature rotary kiln pyrolysis at 3MW fuel power for scale up investigation. ► Rotary kiln pyrolysis of straw and dry distiller's grains with solubles. ► Variation of pyrolysis temperature between 450°C and 600°C. ► Chemical efficiency up to 67% achieved.Analytical pyrolysis studies of corn stalk and its three main components by TG-MS and Py-GC/MS
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Gaojin Lv, Shubin Wu
The pyrolysis behaviors of corn stalk and its three real components (i.e. hemicellulose, cellulose, and lignin) have been investigated with the techniques of TG-MS and Py-GC/MS. The thermal behavior and the evolution profiles of major volatile fragments from each sample pyrolysis have been discussed in depth, while paying close attention to the impact and contributions of each component on the raw material pyrolysis. It was found that pyrolysis of the corn stalk was a comprehensive reflection of its three main components both on thermogravimetric characteristics and on products distribution and their formation profiles. Hemicellulose definitely made the greatest contribution to the formation of acids and ketones at around 300°C. Cellulose was more dedicated to the products of furans and small molecule aldehydes in a short temperature range 320–410°C. While lignin mainly contributed to produce phenols and heterocyclic compounds over a wider temperature range 240–550°C. The experimental results obtained in the present work are of interest for further studies on selective fast pyrolysis of biomass into energy and chemicals.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Gaojin Lv, Shubin Wu
The pyrolysis behaviors of corn stalk and its three real components (i.e. hemicellulose, cellulose, and lignin) have been investigated with the techniques of TG-MS and Py-GC/MS. The thermal behavior and the evolution profiles of major volatile fragments from each sample pyrolysis have been discussed in depth, while paying close attention to the impact and contributions of each component on the raw material pyrolysis. It was found that pyrolysis of the corn stalk was a comprehensive reflection of its three main components both on thermogravimetric characteristics and on products distribution and their formation profiles. Hemicellulose definitely made the greatest contribution to the formation of acids and ketones at around 300°C. Cellulose was more dedicated to the products of furans and small molecule aldehydes in a short temperature range 320–410°C. While lignin mainly contributed to produce phenols and heterocyclic compounds over a wider temperature range 240–550°C. The experimental results obtained in the present work are of interest for further studies on selective fast pyrolysis of biomass into energy and chemicals.
Highlights
► Each actual component of corn stalk was used for pyrolysis studies. ► Thermochemical stabilities of samples were first compared under the same conditions. ► Py-GC/MS and TG-MS used in combination to provide more pyrolysis information. ► Impact and contributions of components on raw material pyrolysis were discussed.Surface characterization and comparative adsorption properties of Cr(VI) on pyrolysed adsorbents of Acacia mangium wood and Phoenix dactylifera L. stone carbon
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mohammed Danish, Rokiah Hashim, M.N. Mohamad Ibrahim, Mohd Rafatullah, Othman Sulaiman
The adsorbents were prepared from wood (Acacia mangium) and date (Phoenix dactylifera L.) stones by pyrolysis in the presence of purified nitrogen gas. The obtained adsorbents [physically activated wood carbon (WC) and date stone carbon (DC)] were characterized for their surface area through Brunauer–Emmet–Teller (BET) isotherms. The BET surface areas of WC and DC were 377.18±2.48 and 59.42±0.80m2/g respectively. The surface morphology and functional groups of the adsorbents were respectively determined from the field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FT-IR) analysis. Microcrystalline size of the pyrolysed adsorbents were also studied with the help of powder X-ray diffraction technique, and the average crystallite sizes were found to be 49.9nm and 32.9nm for WC and DC, respectively. Thermal stability of raw as well as pyrolysed material was analyzed by thermal gravimetric analysis (TGA) and differential thermograph (DTG) plots. The WC and DC have around 60% and 90%, respectively of thermally non-degradable constituents at a temperature up to 800°C. Adsorption properties of Cr(VI) on WC and DC were studied by batch method. The effects of pH on the adsorption process studied showed that removal was favored at pH 2.0 for both adsorbents. The results showed that Cr(VI) removal followed the pseudo-second order model for both the adsorbents. Intraparticle diffusion kinetic model was also tested and it was found that WC followed the two stage diffusion whereas, DC followed single stage diffusion. Experimentally, the adsorption capacities of WC and DC were found to be 37.16 and 32.76mg/g respectively. The applicability of the Freundlich isotherm for WC and Langmuir isotherm for DC adsorption behavior on Cr(VI) have been verified. The thermodynamic parameters (ΔG°, ΔH°, ΔS° and K C) values indicate the spontaneous and endothermic nature of Cr(VI) adsorption on WC and DC.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mohammed Danish, Rokiah Hashim, M.N. Mohamad Ibrahim, Mohd Rafatullah, Othman Sulaiman
The adsorbents were prepared from wood (Acacia mangium) and date (Phoenix dactylifera L.) stones by pyrolysis in the presence of purified nitrogen gas. The obtained adsorbents [physically activated wood carbon (WC) and date stone carbon (DC)] were characterized for their surface area through Brunauer–Emmet–Teller (BET) isotherms. The BET surface areas of WC and DC were 377.18±2.48 and 59.42±0.80m2/g respectively. The surface morphology and functional groups of the adsorbents were respectively determined from the field emission scanning electron microscopy (FESEM) and Fourier transform infrared (FT-IR) analysis. Microcrystalline size of the pyrolysed adsorbents were also studied with the help of powder X-ray diffraction technique, and the average crystallite sizes were found to be 49.9nm and 32.9nm for WC and DC, respectively. Thermal stability of raw as well as pyrolysed material was analyzed by thermal gravimetric analysis (TGA) and differential thermograph (DTG) plots. The WC and DC have around 60% and 90%, respectively of thermally non-degradable constituents at a temperature up to 800°C. Adsorption properties of Cr(VI) on WC and DC were studied by batch method. The effects of pH on the adsorption process studied showed that removal was favored at pH 2.0 for both adsorbents. The results showed that Cr(VI) removal followed the pseudo-second order model for both the adsorbents. Intraparticle diffusion kinetic model was also tested and it was found that WC followed the two stage diffusion whereas, DC followed single stage diffusion. Experimentally, the adsorption capacities of WC and DC were found to be 37.16 and 32.76mg/g respectively. The applicability of the Freundlich isotherm for WC and Langmuir isotherm for DC adsorption behavior on Cr(VI) have been verified. The thermodynamic parameters (ΔG°, ΔH°, ΔS° and K C) values indicate the spontaneous and endothermic nature of Cr(VI) adsorption on WC and DC.
Highlights
► Adsorbents were prepared from natural renewable biomass by pyrolysis. ► Surface characterization was done with the help of suitable techniques. ► Low pH favours the adsorption for both adsorbents. ► Wood carbon showed higher adsorption capacity than stone carbon.Study on pyrolysis characteristics of refuse plastic fuel using lab-scale tube furnace and thermogravimetric analysis reactor
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Sang Shin Park, Dong Kyun Seo, Sang Hoon Lee, Tae-U. Yu, Jungho Hwang
Product yields of liquid, solid, and gas were obtained from pyrolysis experiments on RPF using a tube furnace in a nitrogen atmosphere under three non-isothermal conditions (maximum temperature: 400°C, 600°C, and 800°C). And, the effect of the temperature on the product yields of liquid, solid, and gas were discussed. The gas compositions and liquid compounds were analyzed using gas chromatography (GC) and gas chromatography mass spectrum detector (GC–MSD), respectively. Using a thermogravimetric analysis (TGA) reactor, thermal decomposition characteristics of PS, PVC, LDPE, and PP as well as RPF during pyrolysis were analyzed. Using the single reaction model, the activation energy and pre-exponential factor for RPF pyrolysis were 211.11kJ/mol and 9.04E+13l/min, respectively. Using the parallel reaction model, the activation energies of PS, PP, LDPE, PVC{1}, and PVC{2} (subscripts {1} and {2} refer to the first and second degradation of PVC in mass) were 231.83, 193.55, 175.92, 72.26, and 164.94kJ/mol, respectively, and their pre-exponential factors were 2.27E+17, 4.49E+13, 7.09E+11, 1.24E+06 and 2.16E+11l/min, respectively.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Sang Shin Park, Dong Kyun Seo, Sang Hoon Lee, Tae-U. Yu, Jungho Hwang
Product yields of liquid, solid, and gas were obtained from pyrolysis experiments on RPF using a tube furnace in a nitrogen atmosphere under three non-isothermal conditions (maximum temperature: 400°C, 600°C, and 800°C). And, the effect of the temperature on the product yields of liquid, solid, and gas were discussed. The gas compositions and liquid compounds were analyzed using gas chromatography (GC) and gas chromatography mass spectrum detector (GC–MSD), respectively. Using a thermogravimetric analysis (TGA) reactor, thermal decomposition characteristics of PS, PVC, LDPE, and PP as well as RPF during pyrolysis were analyzed. Using the single reaction model, the activation energy and pre-exponential factor for RPF pyrolysis were 211.11kJ/mol and 9.04E+13l/min, respectively. Using the parallel reaction model, the activation energies of PS, PP, LDPE, PVC{1}, and PVC{2} (subscripts {1} and {2} refer to the first and second degradation of PVC in mass) were 231.83, 193.55, 175.92, 72.26, and 164.94kJ/mol, respectively, and their pre-exponential factors were 2.27E+17, 4.49E+13, 7.09E+11, 1.24E+06 and 2.16E+11l/min, respectively.
Highlights
► The product yields of liquid, solid, and gas were obtained for RPF pyrolysis. ► The gas compositions and liquid compounds were analyzed using GC and GC–MSD. ► Thermal characteristics for RPF, PS, PVC, PP, and LDPE were analyzed using TGA. ► Kinetic parameters for RPF, PS, PP, LDPE, and PVC were obtained.Comparison between the “one-step” and “two-step” catalytic pyrolysis of pine bark
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Ahmet Güngör, Sermin Önenç, Suat Uçar, Jale Yanik
In this study, one-step and two-step pyrolysis systems were compared in the pyrolysis of pine bark. One-step pyrolysis was performed in a fixed bed reactor with and without catalyst. Two-step pyrolysis was carried out in a dual reactor system over catalyst; the first reactor containing no catalyst whereas the second reactor containing catalyst to upgrade the thermally cracked products. The catalysts used in the pyrolysis systems were ReUS-Y, red mud and ZSM-5. In thermal pyrolysis, the pyrolysis system mainly affected the relative amount of bio-oil. The bio-oil yields obtained from two-step thermal pyrolysis were higher than the yields from one-step thermal pyrolysis. In the catalytic runs, ReUS-Y catalyst slightly decreased the char formation with a consequent increase in aqueous phase yield in the case of one-step pyrolysis. However, the catalysts decreased the bio-oil yield with a consequent increase in the gas yield in the case of two-step pyrolysis. The general compositions of bio-oils obtained from both two pyrolysis systems were affected by using catalysts. In the case of one-step pyrolysis, the formation of water and water soluble compounds were reduced by using ReUS-Y catalyst. In the case of two-step pyrolysis, both ZSM-5 and red mud increased the formation of water soluble compounds while they decreased water formation. In contrast, ReUS-Y decreased the formation of water soluble compounds and increased the amount of pyrolytic lignin compounds in bio-oil. Fuel characteristics of pyrolysis products (gas, bio-oil and char) for both two pyrolysis systems were also investigated comparatively.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Ahmet Güngör, Sermin Önenç, Suat Uçar, Jale Yanik
In this study, one-step and two-step pyrolysis systems were compared in the pyrolysis of pine bark. One-step pyrolysis was performed in a fixed bed reactor with and without catalyst. Two-step pyrolysis was carried out in a dual reactor system over catalyst; the first reactor containing no catalyst whereas the second reactor containing catalyst to upgrade the thermally cracked products. The catalysts used in the pyrolysis systems were ReUS-Y, red mud and ZSM-5. In thermal pyrolysis, the pyrolysis system mainly affected the relative amount of bio-oil. The bio-oil yields obtained from two-step thermal pyrolysis were higher than the yields from one-step thermal pyrolysis. In the catalytic runs, ReUS-Y catalyst slightly decreased the char formation with a consequent increase in aqueous phase yield in the case of one-step pyrolysis. However, the catalysts decreased the bio-oil yield with a consequent increase in the gas yield in the case of two-step pyrolysis. The general compositions of bio-oils obtained from both two pyrolysis systems were affected by using catalysts. In the case of one-step pyrolysis, the formation of water and water soluble compounds were reduced by using ReUS-Y catalyst. In the case of two-step pyrolysis, both ZSM-5 and red mud increased the formation of water soluble compounds while they decreased water formation. In contrast, ReUS-Y decreased the formation of water soluble compounds and increased the amount of pyrolytic lignin compounds in bio-oil. Fuel characteristics of pyrolysis products (gas, bio-oil and char) for both two pyrolysis systems were also investigated comparatively.
Highlights
► The bio-oil yields from two-step thermal pyrolysis of pine bark were more than that from one-step thermal pyrolysis. ► The catalytic effect on bio-oil yield was pronounced in two step pyrolysis, leading to decrease in the bio-oil yield. ► The ZSM-5 catalyst was the most effective for decreasing in bio-oil yield followed by ReUS-Y and red mud.Characterization of the water-insoluble pyrolytic cellulose from cellulose pyrolysis oil
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Xinlai Wei, Qiang Lu, Xianwei Sui, Zhi Wang, Ying Zhang
Water-insoluble pyrolytic cellulose with similar appearance to pyrolytic lignin was found in cellulose fast pyrolysis oil. The influence of pyrolysis temperature on pyrolytic cellulose was studied in a temperature range of 300–600°C. The yield of the pyrolytic cellulose increased with temperature rising. The pyrolytic cellulose was characterized by various methods. The molecular weight distribution of pyrolytic cellulose was analyzed by gel permeation chromatography (GPC). Four molecular weight ranges were observed, and the M w of the pyrolytic cellulose varied from 3.4×103 to 1.93×105 g/mol. According to the elemental analysis (EA), the pyrolytic cellulose possessed higher carbon content and lower oxygen content than cellulose. Thermogravimetric analysis (TGA) indicated that the pyrolytic cellulose underwent thermo-degradation at 127–800°C and three mass loss peaks were observed. Detected by the pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), the main pyrolysis products of the pyrolytic cellulose included saccharides, ketones, acids, furans and others. Fourier transforms infrared spectroscopy (FTIR) also demonstrated that the pyrolytic cellulose had peaks assigned to CO stretching and glycosidic bond, which agreed well with the Py-GC/MS results. The pyrolytic cellulose could be a mixture of saccharides, ketones, and their derivatives.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Xinlai Wei, Qiang Lu, Xianwei Sui, Zhi Wang, Ying Zhang
Water-insoluble pyrolytic cellulose with similar appearance to pyrolytic lignin was found in cellulose fast pyrolysis oil. The influence of pyrolysis temperature on pyrolytic cellulose was studied in a temperature range of 300–600°C. The yield of the pyrolytic cellulose increased with temperature rising. The pyrolytic cellulose was characterized by various methods. The molecular weight distribution of pyrolytic cellulose was analyzed by gel permeation chromatography (GPC). Four molecular weight ranges were observed, and the M w of the pyrolytic cellulose varied from 3.4×103 to 1.93×105 g/mol. According to the elemental analysis (EA), the pyrolytic cellulose possessed higher carbon content and lower oxygen content than cellulose. Thermogravimetric analysis (TGA) indicated that the pyrolytic cellulose underwent thermo-degradation at 127–800°C and three mass loss peaks were observed. Detected by the pyrolysis gas chromatography–mass spectrometry (Py-GC/MS), the main pyrolysis products of the pyrolytic cellulose included saccharides, ketones, acids, furans and others. Fourier transforms infrared spectroscopy (FTIR) also demonstrated that the pyrolytic cellulose had peaks assigned to CO stretching and glycosidic bond, which agreed well with the Py-GC/MS results. The pyrolytic cellulose could be a mixture of saccharides, ketones, and their derivatives.
Highlights
► Water-insoluble pyrolytic cellulose was isolated from cellulose fast pyrolysis oil by water precipitation. ► The pyrolysis temperature effect on the pyrolytic cellulose production was investigated. ► The pyrolytic cellulose was characterized by GPC, EA, TGA, Py-GC/MS and FTIR. ► The pyrolytic cellulose underwent thermo-degradation at 127–800°C and three mass loss peaks were observed. ► The structures of polysaccharide and ketones were detected in the pyrolytic cellulose.Novel preparation and properties of magnesioferrite nanoparticles
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
N.M. Deraz, A. Alarifi
Nano-magnetic magnesium ferrite particles were synthesized by a simple and cost-effective method using different ratios between Mg/Fe precursors and fuel. Significant effects of these ratios on the crystalline phases, crystallite size, particle size, lattice constant, morphological and magnetic properties of the as-synthesized nano-particles have been investigated. Phase evolution, morphological and magnetic characteristics were determined by XRD, SEM, EDX and VSM techniques. The results obtained revealed that the as-prepared Mg ferrite nano-particles have the nanometer size and partially inverse spinel structure. Nano-structured magnesium ferrite spinel has been synthesized with various cyrystallite sizes ranging from 8 to 66nm. Room temperature magnetization results showed that the magnetic properties of Mg ferrite nano-particles depend upon their size and crystallinity. The saturation magnetization for the sample having the highest crystallite size was 32.85emu/g.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
N.M. Deraz, A. Alarifi
Nano-magnetic magnesium ferrite particles were synthesized by a simple and cost-effective method using different ratios between Mg/Fe precursors and fuel. Significant effects of these ratios on the crystalline phases, crystallite size, particle size, lattice constant, morphological and magnetic properties of the as-synthesized nano-particles have been investigated. Phase evolution, morphological and magnetic characteristics were determined by XRD, SEM, EDX and VSM techniques. The results obtained revealed that the as-prepared Mg ferrite nano-particles have the nanometer size and partially inverse spinel structure. Nano-structured magnesium ferrite spinel has been synthesized with various cyrystallite sizes ranging from 8 to 66nm. Room temperature magnetization results showed that the magnetic properties of Mg ferrite nano-particles depend upon their size and crystallinity. The saturation magnetization for the sample having the highest crystallite size was 32.85emu/g.
Highlights
► Nano-magnetic magnesium ferrites have been prepared using combustion. ► The magnetism of Mg-ferrite was found to increase by increasing the amount of fuel. ► The structural properties of Mg-ferrites changed with the change in fuel content. ► This treatment brought about change in the microstructure of Mg ferrite.Is nitrogen functionality responsible for contrasted responses of riverine dissolved organic matter in pyrolysis?
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
J. Templier, F. Miserque, N. Barré, F. Mercier, J.-P. Croué, S. Derenne
Fractions of dissolved organic matter (DOM) from the Loire and the Gartempe rivers were obtained using Amberlite XAD resin fractionation procedure. According to the eluting system used and to the polarity of their components, the fractions were termed hydrophobic (HPO) and transphilic (TPI) for the Loire (elution with acetonitrile/water mixture) and hydrophobic acid (HPOA) and transphilic acid (TPIA) for the Gartempe (elution with NaOH). In addition, for the Loire, colloids (COL) were pre-isolated through a dialysis step. The composition of the three fractions from the Loire was investigated with solid state cross polarisation/magic angle spinning (CP/MAS) 13C NMR and Curie point pyrolysis at 650°C with and without tetramethylammonium hydroxide (TMAH). Separation and identification of the released compounds were performed using gas-chromatography/mass spectrometry (GC/MS) and focussed on nitrogen-containing pyrolysis products (N-products). Quantitative differences were observed between the N-product distribution of the HPO and TPI fractions, whilst the few N-products from the COL fraction exhibited different structures corresponding to peptidoglycan contribution. Comparison with previous results obtained for two DOM fractions (HPOA and TPIA) from the Gartempe river (France) revealed that pyrolysis detection of nitrogen containing molecules is not only related to the nitrogen content of the fractions, even in the case of similar hydrophobicity, but also likely to the functionality of nitrogen in the macromolecule sources. To correlate the molecular level information about N-containing moieties with the functionality of nitrogen in the macromolecular sources, the five fractions of DOM were investigated through X-ray photoelectron spectroscopy (XPS) and solid state cross polarisation/magic angle spinning (CP/MAS) 15N NMR. C1s XPS and 15N NMR analyses revealed an important contribution from amide nitrogen in all the DOM fractions, with a large increase from the hydrophobic fractions to the transphilic and colloids ones. Moreover, 15N NMR revealed an additional pyrrole nitrogen contribution in the HPO fraction of the Loire and in the TPI and TPIA fractions of both rivers. For the two rivers, the δ 15N values were maximal for the fraction containing the highest proportion of amide N, and decreased in parallel with increasing pyrrole N contribution. Only the hydrophobic acid fraction of the Gartempe, which did not contain any pyrrole N was characterised by a lack of N-containing pyrolysis products, suggesting that their detection could be dependent on the presence of pyrrole N in the macromolecule sources.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
J. Templier, F. Miserque, N. Barré, F. Mercier, J.-P. Croué, S. Derenne
Fractions of dissolved organic matter (DOM) from the Loire and the Gartempe rivers were obtained using Amberlite XAD resin fractionation procedure. According to the eluting system used and to the polarity of their components, the fractions were termed hydrophobic (HPO) and transphilic (TPI) for the Loire (elution with acetonitrile/water mixture) and hydrophobic acid (HPOA) and transphilic acid (TPIA) for the Gartempe (elution with NaOH). In addition, for the Loire, colloids (COL) were pre-isolated through a dialysis step. The composition of the three fractions from the Loire was investigated with solid state cross polarisation/magic angle spinning (CP/MAS) 13C NMR and Curie point pyrolysis at 650°C with and without tetramethylammonium hydroxide (TMAH). Separation and identification of the released compounds were performed using gas-chromatography/mass spectrometry (GC/MS) and focussed on nitrogen-containing pyrolysis products (N-products). Quantitative differences were observed between the N-product distribution of the HPO and TPI fractions, whilst the few N-products from the COL fraction exhibited different structures corresponding to peptidoglycan contribution. Comparison with previous results obtained for two DOM fractions (HPOA and TPIA) from the Gartempe river (France) revealed that pyrolysis detection of nitrogen containing molecules is not only related to the nitrogen content of the fractions, even in the case of similar hydrophobicity, but also likely to the functionality of nitrogen in the macromolecule sources. To correlate the molecular level information about N-containing moieties with the functionality of nitrogen in the macromolecular sources, the five fractions of DOM were investigated through X-ray photoelectron spectroscopy (XPS) and solid state cross polarisation/magic angle spinning (CP/MAS) 15N NMR. C1s XPS and 15N NMR analyses revealed an important contribution from amide nitrogen in all the DOM fractions, with a large increase from the hydrophobic fractions to the transphilic and colloids ones. Moreover, 15N NMR revealed an additional pyrrole nitrogen contribution in the HPO fraction of the Loire and in the TPI and TPIA fractions of both rivers. For the two rivers, the δ 15N values were maximal for the fraction containing the highest proportion of amide N, and decreased in parallel with increasing pyrrole N contribution. Only the hydrophobic acid fraction of the Gartempe, which did not contain any pyrrole N was characterised by a lack of N-containing pyrolysis products, suggesting that their detection could be dependent on the presence of pyrrole N in the macromolecule sources.
Highlights
► Contrasted detection of N-products when using Curie-point pyrolysis. ► Different but comparable fractions of riverine dissolved organic matter (DOM). ► C1s XPS and 15N NMR studies revealed different nitrogen functionalities. ► Correlation N-products/functionality of nitrogen in the macromolecular sources.Influence of particle size and kinetic parameters on tire pyrolysis
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
J. Haydary, Ľ. Jelemenský, L. Gašparovič, J. Markoš
One of the most important parameters that can significantly affect the cost of the tire pyrolysis process is the time needed for thermal decomposition of the tire material. In this work, the influence of particle size and kinetics of thermal decomposition on the pyrolysis time was studied. The apparent kinetic parameters of tire thermal decomposition were estimated using three different approaches based on thermogravimetry measurements. In separate experiments, tire particles with different sizes were pyrolyzed under isothermal conditions in a laboratory flow reactor at different residence times of the particles in the reactor and the data recorded were employed in the determination of tire conversion during the thermal decomposition. A mathematical model of tire pyrolysis considering heat conduction in the tire particles was developed. All three types of estimated kinetic parameters were used to determine the conversion behavior at isothermal conditions and the results were compared with experimental data obtained. The model was used also to calculate the pyrolysis time in an industrial scale reactor at different temperatures and particle sizes.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
J. Haydary, Ľ. Jelemenský, L. Gašparovič, J. Markoš
One of the most important parameters that can significantly affect the cost of the tire pyrolysis process is the time needed for thermal decomposition of the tire material. In this work, the influence of particle size and kinetics of thermal decomposition on the pyrolysis time was studied. The apparent kinetic parameters of tire thermal decomposition were estimated using three different approaches based on thermogravimetry measurements. In separate experiments, tire particles with different sizes were pyrolyzed under isothermal conditions in a laboratory flow reactor at different residence times of the particles in the reactor and the data recorded were employed in the determination of tire conversion during the thermal decomposition. A mathematical model of tire pyrolysis considering heat conduction in the tire particles was developed. All three types of estimated kinetic parameters were used to determine the conversion behavior at isothermal conditions and the results were compared with experimental data obtained. The model was used also to calculate the pyrolysis time in an industrial scale reactor at different temperatures and particle sizes.
Highlights
► The effect of particle size was estimated experimentally and by modeling. ► Kinetic parameters of tire pyrolysis were estimated by three different methods. ► Conversion of tire particles with different sizes was determined experimentally. ► Determined kinetic parameters and heat transfer parameters were used in a model. ► Calculated conversions were compared with experimental estimated.Preparation and characterization of adsorbents for treatment of water associated with oil production
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mark Sueyoshi, Rashid S. Al-Maamari, Baba Jibril, Masaharu Tasaki, Kazuo Okamura, Hitoshi Kuwagaki, Hidenori Yahiro, Kunimasa Sagata, Yu Han
Two sets of adsorbents were prepared from locally available raw materials, characterized and tested. The first set consists of crushed natural attapulgite and crushed attapulgite mixed with petroleum tank-bottom sludge and carbonized at 650°C. Another set was prepared using trunk of date palm tree (Phoenix dactylifera) activated at 700 and 800°C. Both sets were characterized using BET surface area and pore distributions, FTIR, XRD, SEM and TEM. Natural attapulgite and attapulgite/sludge composite exhibited different characteristics and adsorptive capacities for oil removal from oily water. Adsorptive capacities were calculated from the breakthrough curves of a column test. An oily water solution of about 500mg-oil/L was passed through both the attapulgite and attapulgite/sludge columns until the column effluent concentration exceeded a reference limit of 10mg-oil/L. Uptake was calculated at this limit at 155 and 405mg-oil/g-adsorbent, respectively. This was lower than the performance of a commercial activated carbon sample (uptake calculated at 730mg-oil/g-adsorbent). Relatively, the date palm, carbonaceous-based adsorbent samples showed less significant differences in both bulk and surface properties. Uptake significantly improved to 1330–1425mg-oil/g-adsorbent. Attempt was made to associate this performance with the difference in the surface areas between the two sets. However, other factors are found to be important as the second set has a range of surface area less than that of the commercial sample. As evidenced by FTIR, XRD and TEM, the activated carbonaceous materials developed porous structures which form defective graphitic sheet ensembles that serve as additional adsorption sites in the sample.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mark Sueyoshi, Rashid S. Al-Maamari, Baba Jibril, Masaharu Tasaki, Kazuo Okamura, Hitoshi Kuwagaki, Hidenori Yahiro, Kunimasa Sagata, Yu Han
Two sets of adsorbents were prepared from locally available raw materials, characterized and tested. The first set consists of crushed natural attapulgite and crushed attapulgite mixed with petroleum tank-bottom sludge and carbonized at 650°C. Another set was prepared using trunk of date palm tree (Phoenix dactylifera) activated at 700 and 800°C. Both sets were characterized using BET surface area and pore distributions, FTIR, XRD, SEM and TEM. Natural attapulgite and attapulgite/sludge composite exhibited different characteristics and adsorptive capacities for oil removal from oily water. Adsorptive capacities were calculated from the breakthrough curves of a column test. An oily water solution of about 500mg-oil/L was passed through both the attapulgite and attapulgite/sludge columns until the column effluent concentration exceeded a reference limit of 10mg-oil/L. Uptake was calculated at this limit at 155 and 405mg-oil/g-adsorbent, respectively. This was lower than the performance of a commercial activated carbon sample (uptake calculated at 730mg-oil/g-adsorbent). Relatively, the date palm, carbonaceous-based adsorbent samples showed less significant differences in both bulk and surface properties. Uptake significantly improved to 1330–1425mg-oil/g-adsorbent. Attempt was made to associate this performance with the difference in the surface areas between the two sets. However, other factors are found to be important as the second set has a range of surface area less than that of the commercial sample. As evidenced by FTIR, XRD and TEM, the activated carbonaceous materials developed porous structures which form defective graphitic sheet ensembles that serve as additional adsorption sites in the sample.
Highlights
► Locally available materials were utilized to make adsorbents and characterized. ► Attapulgite and its mixture with sludge exhibited low oil adsorption from water. ► Physically activated date palm trunk exhibited high oil adsorption from water. ► In addition to the nature of pores, graphitic band response is an important factor.Synthesis, crystal structure modeling and thermal decomposition of yttrium propionate [Y2(CH3CH2COO)6·H2O]·3.5H2O
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
M. Nasui, C. Bogatan (Pop), L. Ciontea, T. Petrisor
An yttrium propionate complex was synthesized and characterized for its application as precursor for Y2O3 based oxide thin films deposition and YBa2Cu3O7− x superconducting thin films. The TG–DTA and FT-IR analyses have revealed the formation of an yttrium propionate complex with the formula [Y2(CH3CH2COO)6·H2O]·3.5H2O. The molecular structure of the yttrium propionate complex was determined by modeling the FT-IR spectra. The coordination numbers for the yttrium ions are eight and nine, respectively being coordinated by bridging bimetallic triconnective and chelating bidentate propionate groups. The thermal decomposition of yttrium propionate has been investigated by thermogravimetric (TG) and differential thermal analysis (DTA) coupled with quadrupole mass spectrometry (QMS), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
M. Nasui, C. Bogatan (Pop), L. Ciontea, T. Petrisor
An yttrium propionate complex was synthesized and characterized for its application as precursor for Y2O3 based oxide thin films deposition and YBa2Cu3O7− x superconducting thin films. The TG–DTA and FT-IR analyses have revealed the formation of an yttrium propionate complex with the formula [Y2(CH3CH2COO)6·H2O]·3.5H2O. The molecular structure of the yttrium propionate complex was determined by modeling the FT-IR spectra. The coordination numbers for the yttrium ions are eight and nine, respectively being coordinated by bridging bimetallic triconnective and chelating bidentate propionate groups. The thermal decomposition of yttrium propionate has been investigated by thermogravimetric (TG) and differential thermal analysis (DTA) coupled with quadrupole mass spectrometry (QMS), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR) techniques.
Highlights
► An yttrium propionate complex was synthesized and characterized. ►The molecular structure, as determined by modeling is Y2(CH3CH2COO)6·H2O. ►We proposed a reaction mechanism of the yttrium propionate.Preparation of Si/O/C nanotubes using Ge nanowires as template
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Lubomír Krabáč, Mariana Klementová, Jan Šubrt, Radek Fajgar, Jaroslav Kupčík, Zdeněk Bastl, The Ha Stuchlíková, Vladislav Dřínek
The silicon oxycarbide Si/O/C nanotubes were prepared by two-step procedure. First, a nanostructure deposit mainly composed of nanocables with germanium core was synthetized by low pressure chemical vapor deposition (LPCVD) using hexamethyldigermane Ge2Me6 and 1,1,3,3-tetramethyldisilazane (Me2SiH)2NH as the volatile precursors. Second, LPCVD was followed by annealing at 850°C in vacuum to evaporate germanium core. As a result Si/O/C nanotubes were formed. Various techniques such as Raman spectroscopy, TEM, SEM/EDX, XPS and HRTEM were used to study the physical and chemical properties.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Lubomír Krabáč, Mariana Klementová, Jan Šubrt, Radek Fajgar, Jaroslav Kupčík, Zdeněk Bastl, The Ha Stuchlíková, Vladislav Dřínek
The silicon oxycarbide Si/O/C nanotubes were prepared by two-step procedure. First, a nanostructure deposit mainly composed of nanocables with germanium core was synthetized by low pressure chemical vapor deposition (LPCVD) using hexamethyldigermane Ge2Me6 and 1,1,3,3-tetramethyldisilazane (Me2SiH)2NH as the volatile precursors. Second, LPCVD was followed by annealing at 850°C in vacuum to evaporate germanium core. As a result Si/O/C nanotubes were formed. Various techniques such as Raman spectroscopy, TEM, SEM/EDX, XPS and HRTEM were used to study the physical and chemical properties.
Behavior of intumescent epoxy resins in fireproofing applications
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mercedes Gomez-Mares, Alessandro Tugnoli, Gabriele Landucci, Federica Barontini, Valerio Cozzani
The thermal degradation process of a commercial intumescent epoxy resin for fireproofing applications was investigated. The changes in the morphology of the material during exposure to fire-like conditions were interpreted in the light of the degradation of single material components and of the overall swelling mechanism. An apparent kinetic model was developed to describe the thermally activated conversion and the weight loss of the material. The dramatic change in the key properties of the material (thermal conductivity, volume swelling, and apparent density) was investigated and linked with the thermal degradation phenomena governing the swelling process. Models were developed to describe material properties as a function of temperature and material conversion. The models provide the simulation of the fire-triggered degradation of the sample material at the heating rates of interest, allowing a detailed analysis of fireproofing performance.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mercedes Gomez-Mares, Alessandro Tugnoli, Gabriele Landucci, Federica Barontini, Valerio Cozzani
The thermal degradation process of a commercial intumescent epoxy resin for fireproofing applications was investigated. The changes in the morphology of the material during exposure to fire-like conditions were interpreted in the light of the degradation of single material components and of the overall swelling mechanism. An apparent kinetic model was developed to describe the thermally activated conversion and the weight loss of the material. The dramatic change in the key properties of the material (thermal conductivity, volume swelling, and apparent density) was investigated and linked with the thermal degradation phenomena governing the swelling process. Models were developed to describe material properties as a function of temperature and material conversion. The models provide the simulation of the fire-triggered degradation of the sample material at the heating rates of interest, allowing a detailed analysis of fireproofing performance.
Highlights
► The thermal degradation process of an intumescent epoxy resin was investigated. ► The swelling process during thermal degradation was analyzed. ► A lumped kinetic model for thermal degradation was developed. ► Conversion dependent models were obtained for density, porosity and thermal conductivity. ► Models obtained are crucial to allow an improved description of fireproofing performance.Thermal properties and combustion behaviors of flame retarded epoxy acrylate with a chitosan based flame retardant containing phosphorus and acrylate structure
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Shuang Hu, Lei Song, Haifeng Pan, Yuan Hu, Xinglong Gong
Functional materials prepared from natural resources arouse a great interest recently. Herein, a novel natural material based flame retardant chitosan phosphate acrylate (GPCS) containing phosphorus and acrylate structure has been prepared. Its effect on thermal properties and combustion behaviors of epoxy acrylate (EA) has been investigated. Microscale combustion calorimeter (MCC) data showed that GPCS reduced the peak heat release (PHRR) and total heat release (THR) of samples greatly, which meant that GPCS was efficient in reducing the flammability of EA. The results of thermogravimetric analysis (TGA) exhibited that GPCS improved the thermal stability of materials at high temperature. Investigation of real time Fourier transform infrared (RT-IR) and thermogravimetric analysis/infrared spectrometry (TGA-IR) revealed that GPCS promoted the formation of char and reduced the release of combustible gas. Thermomechanical properties data showed that the storage modulus of samples increased then decreased with increasing GPCS content while the glass transition temperature continued reduced.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Shuang Hu, Lei Song, Haifeng Pan, Yuan Hu, Xinglong Gong
Functional materials prepared from natural resources arouse a great interest recently. Herein, a novel natural material based flame retardant chitosan phosphate acrylate (GPCS) containing phosphorus and acrylate structure has been prepared. Its effect on thermal properties and combustion behaviors of epoxy acrylate (EA) has been investigated. Microscale combustion calorimeter (MCC) data showed that GPCS reduced the peak heat release (PHRR) and total heat release (THR) of samples greatly, which meant that GPCS was efficient in reducing the flammability of EA. The results of thermogravimetric analysis (TGA) exhibited that GPCS improved the thermal stability of materials at high temperature. Investigation of real time Fourier transform infrared (RT-IR) and thermogravimetric analysis/infrared spectrometry (TGA-IR) revealed that GPCS promoted the formation of char and reduced the release of combustible gas. Thermomechanical properties data showed that the storage modulus of samples increased then decreased with increasing GPCS content while the glass transition temperature continued reduced.
Highlights
► A novel natural material based flame retardant chitosan phosphate acrylate (GPCS) has been prepared. ► We investigated the effect of GPCS on thermal and combustion properties of epoxy acrylate. ► The fire hazards of epoxy acrylate reduced greatly.Adsorption of methylene blue onto biomass-based activated carbon by FeCl3 activation: Equilibrium, kinetics, and thermodynamic studies
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Samar K. Theydan, Muthanna J. Ahmed
Ferric chloride has been utilized as an activator for preparation of activated carbon from an agricultural solid waste, date pits. The characteristics of prepared activated carbon (FAC) were determined and found to have a surface area and iodine number of 780.06m2/g and 761.40mg/g, respectively. Experiments were carried out to evaluate the batch adsorption isotherms and kinetics of methylene blue (MB) on FAC at different temperatures. Experimental equilibrium data were analyzed by the Langmuir, Freundlich and Sips isotherm models. The results show that the best fit was achieved with the Sips isotherm equation with a maximum MB adsorption capacity of 259.25mg/g. Pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyze the kinetic data obtained at different initial MB concentrations. The adsorption kinetic data were well described by the pseudo-second order model. The calculated thermodynamic parameters, namely ΔG, ΔH, and ΔS showed that adsorption of MB onto date pits was spontaneous and endothermic under examined conditions.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Samar K. Theydan, Muthanna J. Ahmed
Ferric chloride has been utilized as an activator for preparation of activated carbon from an agricultural solid waste, date pits. The characteristics of prepared activated carbon (FAC) were determined and found to have a surface area and iodine number of 780.06m2/g and 761.40mg/g, respectively. Experiments were carried out to evaluate the batch adsorption isotherms and kinetics of methylene blue (MB) on FAC at different temperatures. Experimental equilibrium data were analyzed by the Langmuir, Freundlich and Sips isotherm models. The results show that the best fit was achieved with the Sips isotherm equation with a maximum MB adsorption capacity of 259.25mg/g. Pseudo-first order, pseudo-second order and intraparticle diffusion models were used to analyze the kinetic data obtained at different initial MB concentrations. The adsorption kinetic data were well described by the pseudo-second order model. The calculated thermodynamic parameters, namely ΔG, ΔH, and ΔS showed that adsorption of MB onto date pits was spontaneous and endothermic under examined conditions.
Highlights
► Activated carbon was prepared from date pits by ferric chloride activation (FAC). ► FAC was used to remove methylene blue (MB) from aqueous solutions. ► Surface area of 780.06m2/g was characterized for FAC. ► Maximum MB capacity of 259.25mg/g was reported using Sips isotherm. ► The kinetic data were well described by pseudo-second order model.Continuous high-temperature fluidized bed pyrolysis of coal in complex atmospheres: Product distribution and pyrolysis gas
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mei Zhong, Zhikai Zhang, Qi Zhou, Junrong Yue, Shiqiu Gao, Guangwen Xu
This study is devoted to investigating the continuous coal pyrolysis in a laboratory fluidized bed reactor that fed coal and discharged char continuously at temperatures of 750–980°C and in N2-base atmospheres containing O2, H2, CO, CH4 and CO2 at varied contents. The results showed that the designed continuous pyrolysis test provided a clear understanding of the coal pyrolysis behavior in various complex atmospheres free of and with O2. The effect of adding H2, CO, CH4 or CO2 into the atmosphere on the tar yield was related to the O2 content in the atmosphere. Without O2 in the atmosphere, adding H2 and CO2 decreased the pyrolysis tar yield, but the tar yield was conversely higher with raising the CO and CH4 contents in the atmosphere. In O2-containing atmospheres, the influence from varying the atmospheric gas composition on the product distribution and pyrolysis gas composition was closely related to the oxidation or gasification reactions occurring to char, tar and the tested gas.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Mei Zhong, Zhikai Zhang, Qi Zhou, Junrong Yue, Shiqiu Gao, Guangwen Xu
This study is devoted to investigating the continuous coal pyrolysis in a laboratory fluidized bed reactor that fed coal and discharged char continuously at temperatures of 750–980°C and in N2-base atmospheres containing O2, H2, CO, CH4 and CO2 at varied contents. The results showed that the designed continuous pyrolysis test provided a clear understanding of the coal pyrolysis behavior in various complex atmospheres free of and with O2. The effect of adding H2, CO, CH4 or CO2 into the atmosphere on the tar yield was related to the O2 content in the atmosphere. Without O2 in the atmosphere, adding H2 and CO2 decreased the pyrolysis tar yield, but the tar yield was conversely higher with raising the CO and CH4 contents in the atmosphere. In O2-containing atmospheres, the influence from varying the atmospheric gas composition on the product distribution and pyrolysis gas composition was closely related to the oxidation or gasification reactions occurring to char, tar and the tested gas.
Highlights
► Coal pyrolysis behaviors were studied in fluidized bed with continuous coal feed and char discharge. ► The yields of product were obtained in complex atmospheres at temperatures from 750°C up to 980°C. ► Raising the ER until 0.107, tar and char yields decreased, while gas and water yields increased. ► In O2-free atmosphere, adding CH4 into the atmosphere increased tar and char yields. ► Adding combustible gas into the N2 +O2 atmosphere increased the tar and char yields.Study on the gas evolution and char structural change during pyrolysis of cotton stalk
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Peng Fu, Song Hu, Jun Xiang, Lushi Sun, Sheng Su, Senmeng An
The gas release properties and char structural evolution during the pyrolysis of cotton stalk were investigated. The evolution characteristics of volatile products were examined by pyrolysis–Fourier transform infrared spectroscopy (FTIR)/thermal conductivity detection (TCD) analysis (Py–FTIR/TCD). The char chemical structure and physical characteristics were investigated by means of FTIR and N2 physisorption techniques. Evolution characteristics of the main volatile products were given. The evolution of CO2 was approximately 26°C earlier than that of CO. CH4 evolution covered over a wider temperature range of 300–600°C, with a maximum at 394°C. The amount of hydroxyl, aliphatic CH and olefinic CC bonds in the char decreased significantly above 250°C. The aromatization process started at ≈350°C and continued to higher temperatures, leaving the char enriched with condensed aromatic ring systems. The BET surface area increased continually with increasing temperature to reach a maximum value of 4.68m2/g at 500°C and decreased at higher temperatures. The micropore volume showed a similar behavior to the surface area, while the mesopore volume and total pore volume always increased.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Peng Fu, Song Hu, Jun Xiang, Lushi Sun, Sheng Su, Senmeng An
The gas release properties and char structural evolution during the pyrolysis of cotton stalk were investigated. The evolution characteristics of volatile products were examined by pyrolysis–Fourier transform infrared spectroscopy (FTIR)/thermal conductivity detection (TCD) analysis (Py–FTIR/TCD). The char chemical structure and physical characteristics were investigated by means of FTIR and N2 physisorption techniques. Evolution characteristics of the main volatile products were given. The evolution of CO2 was approximately 26°C earlier than that of CO. CH4 evolution covered over a wider temperature range of 300–600°C, with a maximum at 394°C. The amount of hydroxyl, aliphatic CH and olefinic CC bonds in the char decreased significantly above 250°C. The aromatization process started at ≈350°C and continued to higher temperatures, leaving the char enriched with condensed aromatic ring systems. The BET surface area increased continually with increasing temperature to reach a maximum value of 4.68m2/g at 500°C and decreased at higher temperatures. The micropore volume showed a similar behavior to the surface area, while the mesopore volume and total pore volume always increased.
Highlights
► Evolution characteristics of main volatile products were given. ► The evolution of CO2 was approximately 26°C earlier than that of CO and CH4 evolution mainly occurred 300–600°C with a maximum at 394°C. ► The amount of OH, aliphatic CH and olefinic CC bonds in the char decreased significantly above 250°C. ► The aromatization process started at ≈350°C and continued to higher temperatures, leaving the char enriched with condensed aromatic ring systems. ► S BET and V micro reached maxima of 4.68m2/g and 0.0022cm3/g at 500°C, while V meso and V total always increased.Synthesis, crystal structure and thermal decomposition of Zr6O4(OH)4(CH3CH2COO)12
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
R.B. Mos, M. Nasui, T. Petrisor, M.S. Gabor, R.A. Varga, L. Ciontea
The present study reports on a novel zirconium oxo-hydroxypropionate complex, obtained by the reaction of zirconium acetylacetonate with propionic acid, used as an oxide precursor for applications in Zr based thin films deposition. The molecular structure of the zirconium precursor has been determined by X-ray diffraction on single crystals and was demonstrated to be [Zr6O4(OH)4(CH3CH2COO)12]2, in good agreement with the formula calculated from the thermogravimetric analysis. The zirconium complex precursor is a three dimensional channel-type polymer. The thermal decomposition of the zirconium precursor has been studied by simultaneous differential thermal analysis-thermogravimetry-mass spectrometry (DTA-TG-MS) both in air and argon atmosphere at a heating rate of 10°C/min. The infrared spectroscopy (FT-IR) has confirmed the molecular structure as determined from the X-ray diffraction on single crystals. The aging of the precursor solution was investigated by NMR relaxometry measurements. The X-ray diffraction on the precursor powder at different temperatures was also performed to investigate the nature of the intermediate decomposition products.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
R.B. Mos, M. Nasui, T. Petrisor, M.S. Gabor, R.A. Varga, L. Ciontea
The present study reports on a novel zirconium oxo-hydroxypropionate complex, obtained by the reaction of zirconium acetylacetonate with propionic acid, used as an oxide precursor for applications in Zr based thin films deposition. The molecular structure of the zirconium precursor has been determined by X-ray diffraction on single crystals and was demonstrated to be [Zr6O4(OH)4(CH3CH2COO)12]2, in good agreement with the formula calculated from the thermogravimetric analysis. The zirconium complex precursor is a three dimensional channel-type polymer. The thermal decomposition of the zirconium precursor has been studied by simultaneous differential thermal analysis-thermogravimetry-mass spectrometry (DTA-TG-MS) both in air and argon atmosphere at a heating rate of 10°C/min. The infrared spectroscopy (FT-IR) has confirmed the molecular structure as determined from the X-ray diffraction on single crystals. The aging of the precursor solution was investigated by NMR relaxometry measurements. The X-ray diffraction on the precursor powder at different temperatures was also performed to investigate the nature of the intermediate decomposition products.
Highlights
► We grown and characterized a new single crystal zirconium oxo-hydroxypropionate complex. ► The X-ray diffraction pattern on the single crystal has revealed that the precursor formula is [Zr6O4(OH)4(CH3CH2COO)12]2. ► We proposed a reaction mechanism of the zirconium precursor.Effects of chromium ion on sulfur removal during pyrolysis and hydropyrolysis of coal
15 August 2012,
08:47:12
Publication year:
2012
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Jiqing Huang, Zongqing Bai, Zhenxing Guo, Wen Li, Jin Bai
The effects of impregnated Cr3+ on sulfur removal during pyrolysis and hydropyrolysis of coal were investigated by loading CrCl3 into raw, demineralized and pyrite removed coal, respectively. The results indicate that Cr has no effect on the removal of pyrite. Cr affects the removal of total sulfur by forming Cr7S8 and affecting the removal of organic sulfur. Cr acts as the sulfur removing agent by promoting the decomposition of the unstable organic sulfur at low temperature. However, it behaves to be sulfur fixing agent between 400 and 700°C so as to inhibit the evolution of H2S, even in hydropyrolysis. With the increase of temperature from 700 to 1050°C, a certain ratio of Cr7S8 is converted into organic sulfur during pyrolysis; however, almost all the Cr7S8 is reduced into Cr at 1050°C during hydropyrolysis. And Cr significantly promotes the removal of organic sulfur at high temperature within reducing atmosphere. The XPS results indicate that the sulfur is enriched on coke surface by Cr, which is attributable to the formation of Cr7S8 as well as the transfer of organic sulfur from bulk to surface during pyrolysis and hydropyrolysis.
Source:Journal of Analytical and Applied Pyrolysis, Volume 97
Jiqing Huang, Zongqing Bai, Zhenxing Guo, Wen Li, Jin Bai
The effects of impregnated Cr3+ on sulfur removal during pyrolysis and hydropyrolysis of coal were investigated by loading CrCl3 into raw, demineralized and pyrite removed coal, respectively. The results indicate that Cr has no effect on the removal of pyrite. Cr affects the removal of total sulfur by forming Cr7S8 and affecting the removal of organic sulfur. Cr acts as the sulfur removing agent by promoting the decomposition of the unstable organic sulfur at low temperature. However, it behaves to be sulfur fixing agent between 400 and 700°C so as to inhibit the evolution of H2S, even in hydropyrolysis. With the increase of temperature from 700 to 1050°C, a certain ratio of Cr7S8 is converted into organic sulfur during pyrolysis; however, almost all the Cr7S8 is reduced into Cr at 1050°C during hydropyrolysis. And Cr significantly promotes the removal of organic sulfur at high temperature within reducing atmosphere. The XPS results indicate that the sulfur is enriched on coke surface by Cr, which is attributable to the formation of Cr7S8 as well as the transfer of organic sulfur from bulk to surface during pyrolysis and hydropyrolysis.
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ReplyDeleteThe most vital parameters which will considerably have an effect on the value of the tire transformation method is that the time required for thermal decomposition of the tire material. during this work, the influence of particle size and mechanics of thermal decomposition on the transformation time was studied.
ReplyDeleteTire Pyrolysis Plant
Some of them are batch type and few are continuous type. But still they have certain problems. We have made an attempt to design a continuous pyrolysis plant with capacity 2 TPD which will meet pollution control board’s requirements .
ReplyDeleteContinuous Plastic Pyrolysis Plants