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  • Study on the synthesis and thermal degradation of Vinylphenylpolysilsesquioxane
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-12
    Liu Tao, Sun Chao, Ma Fengguo

    Vinylphenylpolysilsesquioxane is synthesized through hydrolysis and condensation method, using phenyltrimethoxysilane and dimethylvinylethyoxysilane as raw materials. Its structure is confirmed by Fourier-transformed infrared (FTIR) and nuclear magnetic resonance (NMR) spectra. The degradation of vinylphenylpolysilsesquioxane under nitrogen atmosphere is investigated by thermal analysis techniques combined with infrared spectroscopy (TGA-FTIR) and TGA combined with gas chromatograph-mass spectrometer (TG-GC-MS). Its thermal degradation kinetics and thermal degradation mechanism is inferred from TGA under nitrogen atmosphere. In the light of these analyses, the degradation process is divided into two stages. In the first stage from 170 °C to 465 °C, the thermal degradation products are oligomer polysilsesquioxane, a little CO2 and H2O. Its thermal degradation mechanism is nucleation and growth process, its reaction order was 4. Its thermal degradation kinetics equation is View the MathML source d α d t = 3.25 × 10 17 ( 1 − α ) [ − ln ( 1 − α ) ] − 3 exp ( − 2.73 × 10 4 / T ) .In the second stage, the thermal degradation products are benzene and its derivatives. Its thermal degradation mechanism is nucleation and growth process, its reaction order was 4. Its thermal degradation kinetics equation is View the MathML source d α d t = 5.37 × 10 15 ( 1 − α ) [ − ln ( 1 − α ) ] − 3 exp ( − 3.60 × 10 4 / T ) .

    更新日期:2018-01-13
  • Catalytic hydroliquefaction of rice straw for bio-oil production using Ni/CeO2 catalysts
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-11
    Dongdong Chen, Quanhong Ma, Lingfei Wei, Naixu Li, Quanhao Shen, Wei Tian, Jiancheng Zhou, Jieyu Long
    更新日期:2018-01-11
  • Influence of moisture content on cattle manure char properties and its potential for hydrogen rich gas production
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Ya Xin, Dianlong Wang, XiangQian Li, Qiaoxia Yuan, Hongliang Cao

    Cattle manure with different moisture contents was carbonized under different temperatures to investigate the products distribution and cattle manure char’s properties. And the cattle manure char’s gasification performance was compared with cattle manure to explore the manure char’s gasification potential. Results showed that temperature and moisture content exerted a strong influence on products distribution and cattle manure char properties. Manure char yield decreased and gas yield increased with increasing temperature. Moisture content of 56.20% was favor to improve the gas yield, while moisture content of 85.12% promote the liquid yield. Carbon content in manure char decreased as the moisture content increased, and it increased as temperature increased. The product distribution and elemental analysis results indicated that the C in cattle manure was converted to gas phase at 56.20% moisture content and to liquid phase at 85.12% moisture content. Steam gasification results showed that syngas and hydrogen yields from manure char increased by 1.79 and 2.27 times, respectively, comparing with gasification of cattle manure. And weight loss of manure char (52.00%) was lower than that of cattle manure (83.70%). These indicated that using cattle manure char as gasification feedstock can enhance the reduction of tars in the product gas. In addition, the H2 concentration from manure char reached 59.22%. Therefore, the cattle manure char is a good feedstock for producing hydrogen.

    更新日期:2018-01-11
  • Gas production by catalytic pyrolysis of herb residues using Ni/CaO catalysts
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Anzhuang Xu, Weihong Zhou, Xiaodong Zhang, Baofeng Zhao, Lei Chen, Laizhi Sun, Weijing Ding, Shuangxia Yang, Haibin Guan, Bin Bai

    A series of Ni/CaO catalysts with different ratios of Ni content were prepared by using an isovolumetric impregnation method. The performance of Ni/CaO catalysts on cyclic CO2 absorption and catalytic pyrolysis of herb residues was investigated by using a thermogravimetry and differential thermal analyzer (TG-DTA) and a fixed micro-bed pyrolysis reactor system. The results of cyclic absorption experiments using Ni/CaO catalysts with different ratios of Ni content showed that the CO2 absorption capability of CaO decreased rapidly with increasing number of cycle, and the addition of Ni increased the anti-deactivation capability of CaO in cyclic CO2 absorption. Among the catalysts, the absorption rate of 10% (wt) Ni/CaO was up to 0.7 in the eighth cycle, which was 22.8% higher than that of pure CaO. The analysis of the catalytic pyrolysis products of herb residues indicated that the addition of CaO and 10% (wt) Ni/CaO resulted in effective removal of CO2 in the gaseous products, significant increase in the lower heating value(LHV), and reduction in the yield of condensable liquids such as tar. Compared with CaO, the addition of Ni increased effective gases production and the heating value of the gaseous product and further decreased the yield of condensable liquids. Under the conditions of 700 °C, 10% (wt) Ni/CaO catalyzed pyrolysis of herbal residues yielded an effective gas production of 325.3 mL/g and the lower heating value of 18.6 MJ/m3.

    更新日期:2018-01-11
  • Pyrolysis involving n-hexadecane, water and minerals: Insight into the mechanisms and isotope fractionation for water-hydrocarbon reaction
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Kun He, Shuichang Zhang, Jingkui Mi, Wenlong Zhang

    To ascertain the effects of minerals and dissolved salts on gas generation from water-hydrocarbon reaction, a series of pyrolysis of n-C16 with water and different minerals or salt solutions at 330–420 °C and 50 MPa were conducted in a gold-tube pyrolysis apparatus. It was shown that both calcite and montmorillonite exhibited evidently catalytic effects on gas generation in pyrolysis of hydrocarbon involving water at elevated temperature. The evident higher D/H ratios of methane in hydrous pyrolysis using deuterated water demonstrate that water provided H or D for hydrocarbon gas generation in water-hydrocarbon reaction. Meanwhile, the presence of two minerals resulted in the distinct distribution of the isomeric index (i-C4/n-C4) and carbon isotopic compositions for gas products. In addition, there was a negative correlation between gas yields/isomeric index and NaCl/KCl concentrations in hydrous pyrolysis of n-C16. Theoretical calculations based on density functional theory (DFT) and transition states (TS) revealed that the activation energies for reactions between alkenes and H+ or water are much lower than those involving water and other organic compounds. The water-hydrocarbon reaction in this study should mainly occur via ionic mechanism, though free radical reaction between alkyl radicals and water also presented. Moreover, it was demonstrated that ionic and free radical mechanisms dominated the water-hydrocarbon reaction with montmorillonite and calcite, respectively. The effects of dissolved salts on water-hydrocarbon reaction can be interpreted by the evolution of H+ concentration with salt concentration in aqueous solutions at elevated temperature. In addition, the differences in carbon isotope fractionation for methane generation from water-hydrocarbon reaction via free radical and ionic mechanisms were addressed. Hydrogen isotope fractionation for methane during water-hydrocarbon reaction or hydrogenation by water was also elucidated by thermodynamic calculations. Finally, a model for the prediction of hydrogen isotopic ratios of methane after hydrogen transfer equilibrium between water and methane is proposed.

    更新日期:2018-01-11
  • Analysis of COD and composition identification of carbon matter in the coal-series kaolin
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Teng Huang, Shaomin Lei, Yuanyuan Liu, Mengjiao Ji, Yanming Fan

    Coal-series kaolin is the product of seam deposition in coal-accumulating basin. With small amount of carbon matter, separating and purifying the carbon matter from the kaolin is rather difficult, which may increase difficulties for the cognition and application of coal-series kaolin. Results of this study show that carbon matter has a significant influence on the chemical oxygen demand(COD) of the coal-series kaolin, while the analysis of the chloroform extraction and demineralization residue of kaolin shows that the main structure of carbon matter consists of aromatic hydrocarbon, with one to two benzene units, and the oxygen-containing functional groups mainly consist of phenolic compounds, amino acids. Therefore, the main composition and structure of carbon matter in the coal-series kaolin have been identified for the first time, which will have broad popularizing prospect for the sustainable and efficient utilization of coal-series kaolin.

    更新日期:2018-01-11
  • Biochar from biosolids microwaved-pyrolysis: Characteristics and potential for use as growing media amendment
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Bhawana Bhatta Kaudal, Cristina Aponte, Graham Brodie

    Biochar, produced from biosolids using microwave pyrolysis technology, is energetically a more efficient alternative to that produced with conventional convective heating. However the potential of microwave generated biochar as a growing media amendment has not been sufficiently explored. Here we produced biochar from biosolids using microwave energy. The pyrolysis expeiments were conducted in two stages, initially using a custom built single mode chamber to explore the energetics and product distribution of the pyrolysis process at different temperatures and secondly in a 1 m3 6 kW multi-mode chamber, to explore potential scale-up of the process. The second phase of the pyrolysis experiments was focused on biochar generation for use in the remainder of this research. Microwave pyrolyzed biochar (MB) was characterised for its chemcal and physical properties. Then, we conducted a greenhouse experiment, where we compared the ability of four growing media mixes that combined pine bark with (i) sphagnum peat and fertilizers; (ii) 20% MB and fertilizers; (iii) 60% MB and fertilizers; and (iv) 60% MB and no fertilizers, to promote plant growth and nutrient uptake and to minimise leaching losses. MB had high mesoporosity (average pore width of 4.46 nm), moderate surface area (75 m2 g−1), elevated nutrient content and low heavy metal concentrations as compared to other biosolids biochars reprted in literatures. Substitution of peat with 60% MB on volume basis reduced leaching loss of nitrate and phosphate from the media but increased leaching loss of ammonium. Addition of MB in conjunction with fertilizer increased plant growth and plant nitrogen and phosphorus use efficiency. Our study has shown microwave pyrolysis as a promising technology for pyrolyzing biosolids and also has demonstrated the synergistic interaction of MB and fertilizer which results in greater plant growth and nutrient uptake and use efficiency.

    更新日期:2018-01-11
  • Microwave assisted pyrolysis of crop residues from Vitis vinifera
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Mattia Bartoli, Luca Rosi, Alessio Giovannelli, Piero Frediani, Maurizio Passaponti, Marco Frediani

    A fast pyrolysis of crop residues of Vitis vinifera has been realized using a multimode microwave (MW) oven using various MW absorbers. The combination of absorber/reactor arrangement address the process towards a high formation of bio-oil (34.9%) and gas (45.7%) or the production of large amount of bio-char (up to 71.4%). Bio-oils were collected as dark brown liquids with low viscosity and density. They were characterized through analytical and spectroscopic methods and the compounds present were identified and quantified. Large amount of acetic acid (up to 172.5 g/L) and appreciable amount of aromatics (up to 39.5 g/L) were formed in all experiments. Bio-oil obtained using carbon as MW absorber and set-up B showed the lower water concentration (39.5 wt%). Bio-chars formed in all tests showed almost the same calorific values, close to that of commercial pellets. The MAP of vine residues is a sound way to reduce environmental risks for their disposal and gave usefully chemicals, mainly acetic acid, aromatics and fuels through a fast pyrolysis process.

    更新日期:2018-01-11
  • Increasing light aromatic products during upgrading of lignite pyrolysis vapor over Co-modified HZSM-5
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Xue-Yu Ren, Jing-Pei Cao, Xiao-Yan Zhao, Wen-Zhong Shen, Xian-Yong Wei
    更新日期:2018-01-11
  • Conversion of poultry litter into bio-oil by microwave-assisted catalytic fast pyrolysis using microwave absorbent and hierarchical ZSM-5/MCM-41 catalyst
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Bo Zhang, Jing Zhang, Zhaoping Zhong, Yichi Zhang, Min Song, Xiaojia Wang, Kuan Ding, Roger Ruan
    更新日期:2018-01-11
  • Spray pyrolysis deposited high quality nano-crystalline CdO thin film and their structural, room temperature and selective gas sensing properties
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Umesh T. Nakate, Pramila Patil, Balaji Ghule, Satish Ekar, Revan Ambare, R.S. Mane
    更新日期:2018-01-10
  • Upgrading of lignin pyrolytic-oil model compounds in a catalytic dielectric barrier discharge plasma reactor
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-10
    Xinxin Liu, Tao He, Yuanzheng Ge, Guomin Li, Jingli Wu, Zhiqi Wang, Guangbo Liu, Jinhu Wu

    Catalytic upgrading of anisole and guaiacol in an atmospheric dielectric barrier discharge (DBD) plasma reactor was studied. Compared to thermal upgrading in a fixed bed, the DBD plasma method can convert the model compound to benzene and toluene with high selectivity under relatively low temperature. The synergistic effect between H2 plasma and Ni-Mo/SiO2 catalyst is crucial to the high deoxygenation rate. The primary reactions occurring during the DBD upgrading process include demethylation, methyl transfer, and hydrogenolysis. XRD spectra indicate that phase change should not be the primary reason for catalyst deactivation; GC-MS, NH3-TPD, and regeneration experiments show that carbon deposition is the cause for deactivation. NH3-TPD analysis reveals that a combination of medium and strong acid sites plays an important role in the hydrogenolysis of phenols to benzenes. The present work shows DBD catalytic upgrading as a promising route for the C-O bond hydrogenolysis reaction.

    更新日期:2018-01-10
  • Modeling the Pyrolytic Behavior of Lignin through Two Representative Monomers: Vanillin and Acetovanillone
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-06
    Weikun Jiang, Jiangyong Chu, Shubin Wu, Lucian A. Lucia
    更新日期:2018-01-07
  • Reverse engineering of plastic waste into useful fuel products
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-03
    Prosper Achaw Owusu, Noble Banadda, Ahamada Zziwa, Jeffrey Seay, Nicholas Kiggundu

    This paper’s twofold aims are: to assess the potential of converting plastic waste into useful fuels in both continuous and batch pyrolysis reactors using an appropriate technology and to investigate the effect of silica-alumina catalyst on the yield and quality of pyrolytic liquid oil. The plastic waste used (HDPE, PP and PS) were obtained from Kiteezi landfill site, Kampala (Uganda). In a further step, the properties of the liquid fuel obtained from pyrolysis were also compared with commercial transportation fuel to ascertain its suitability on diesel engines.The fuel qualities were analysed using ASTM standard test methods At a degradation temperature of 450 °C, thermal pyrolysis in a batch reactor resulted in the highest yield of liquid fractions. The liquid yield of HDPE, PP and PS was found to be 80%, 82.6% and 80% by mass, respectively. In contrast, silica-alumina catalyst to feedstock ratio of 1:10 was the most effective in terms of gaseous fraction production. The gaseous fractions were: 60 wt% for the mixture, followed by HDPE (59.63 wt%), PS (59.07 wt%) and PP (49.33 wt%). A catalyst/polymer ratio of 1:10 greatly reduced the degradation temperature. The degradation temperature for HDPE, PP and PS was reduced by about 33%, 23% and 17%, respectively. The liquid oils from HDPE and PP had densities of 0.796 g/cm3 and 0.786 g/cm3; kinematic viscosities of 2.373 mm2/s and 2.115 mm2/s, dynamic viscosities of 1.889 mPas and 1.856 mPas; boiling point ranges of 119–364 °C and 148–355 °C; and cetane indices of 46 and 63, respectively. The characteristics of HDPE and PP pyrolytic sample oils are similar to conventional transportation fuel.

    更新日期:2018-01-03
  • Influence of inherent mineral matrix on the product yield and characterization from Huadian oil shale pyrolysis
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-03
    Zhibing Chang, Mo Chu, Chao Zhang, Shuxia Bai, Hao Lin, Liangbo Ma

    Huadian oil shale was subjected to step-wise acid treatment to remove inherent carbonate and silicate minerals. The original oil shale and its demineralization products (carbonate- and carbonate-silicate-free oil shale samples) were pyrolyzed in a fixed-bed pyrolyzer to determine the mineral matrix effect on product yield and characteristics of shale oil and gases. The shale oil yields of original, carbonate-free, and carbonate-silicate-free oil shale samples were 50.4 wt.%, 44.3 wt.%, and 50.3 wt.% (values on dry and mineral matter-free basis), respectively, which indicated that carbonates promote, while silicates suppress, shale oil production. Coking of aromatic compounds appeared to be the dominant mechanism accounting for the variation of the shale oil yield. Elimination of the carbonate minerals decreased the nitrogen- and oxygen-containing compounds of shale oil, while removal of silicates increased the oxygenated compounds. Both carbonate and silicate minerals decreased the atomic H/C ratio of shale oil. Silicates promoted the cracking and aromatization of aliphatic hydrocarbons, which increased the short-chain aliphatic hydrocarbons and aromatic hydrocarbons of shale oil, as well as C1–C4 hydrocarbons and H2 yields. On the contrary, carbonates suppressed the cracking of long chain aliphatic hydrocarbons.

    更新日期:2018-01-03
  • Decomposition of the ISA-card under steam for valorized polymetallic raw material
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-02
    Monika Zabłocka-Malicka, Włodzimierz Szczepaniak, Piotr Rutkowski, Katarzyna Ochromowicz, Anna Leśniewicz, Jacek Chęcmanowski

    The complete 3Com TokenLink Velocity ISA 16/4 3C319 waste card was gasified under steam at atmospheric pressure in the allothermal process by heating up to 900 °C. The product was easily partitioned according to size and magnetic properties into 5 fractions. Each fraction was analyzed for content of metals by classical chemical route (aqua regia/ICP-OES). With exception of bulky steel parts, these fractions were also investigated by XRD and SEM-EDS methods It was found that there were no bromides in the solid product of gasification. Aqueous condensates, collected in six periods, were individually analyzed for content of bromine and potentially volatile metals (Sn, Zn, and Pb). The composition of tars and oils from condensates and proportions between contents of detected species were also evaluated (GC-MS). Condensation of the excess of steam appeared efficient in the cleaning of the gas from tars, oils, and HBr − final form of bromine. Results of the experiment were discussed and supplemented by the thermodynamic assessment of oxygen potential of the system as well as speciation and volatilization of metals and bromine. Finally, the process was shortly discussed in terms of zero-emissions + zero-waste model as well as the valorization of the waste due to transformation into metal-mineral resource enriched in valuable metals.

    更新日期:2018-01-03
  • Evaluation of chemical structure, pyrolysis reactivity and gaseous products of Shenmu coal of different particle sizes
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-02
    Xiye Chen, Yan Zhao, Li Liu, Linyao Zhang, Zhuo Zhang, Penghua Qiu

    In this study, chemical structure and pyrolysis reactivity of six different coal particle fractions were researched using Fourier transform infrared spectroscopy (FT-IR) and thermogravimetric analysis (TGA), respectively. An on-line FTIR was applied to assess the evolution characteristics of the gaseous products. The results expose that with the particle size decreasing, the ash content of Shenmu coal sample gradually increases, while the pyrolysis reactivity steadily decreases. In addition, the content of hydrogen as well as some typical chemical groups in coal is also affected by particle size. In our experimental conditions, the comprehensive infrared structural parameter has a good linear relation with pyrolysis reactivity. Moreover, with the particle size decreasing, the release amount of CH4, aliphatic hydrocarbons and light aromatic hydrocarbons gradually decreases, while the release amount of CO changes little.

    更新日期:2018-01-03
  • Non-isothermal pyrolysis properties of Laminaria japonica
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2018-01-02
    Tae Uk Han, Young-Min Kim, Muhammad Zain Siddiqui, Taeho Lee, Atsushi Watanabe, Norio Teramae, Seungdo Kim, Young-Kwon Park

    The pyrolysis of Laminaria (L.) japonica was examined using non-isothermal analytical pyrolysis techniques, such as thermogravimetric analysis (TGA) and multi-shot pyrolysis (Py)-gas chromatography/mass spectrometry (GC/MS). TGA, derivative TG, and the apparent activation energy suggested that the decomposition of L. japonica has three thermal decomposition stages. The average mass spectra and multi-shot Py-GC/MS chromatograms obtained at each thermal decomposition stage confirmed the main decomposition reaction at each thermal zone. At the first stage, the decomposition of lipids and carbohydrates was initiated. The main decomposition of carbohydrates occurred at the second stage. At the final stage, proteins were decomposed and char intermediates were stabilized by supplying a higher temperature. A low activation energy at the second stage and the presence of metals in L. japonica suggests that during the non-isothermal pyrolysis of L. japonica, the catalytic effect is enhanced and involves the decomposition of carbohydrates.

    更新日期:2018-01-03
  • Size tunable carbon-encapsulated nickel nanoparticles synthesized by pyrolysis of nickel acetate tetrahydrate
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-29
    Juan C. De Jesús, Salvador García, Daniela Dorante

    In this study, size control of carbon-encapsulated nickel nanoparticles (CENiNPs) synthesized by direct thermal decomposition of Ni(CH3COO)2.4H2O (NiAc) was possible by varying systematically the initial amount of the precursor during its pyrolysis. The reaction was conducted inside a thermogravimetric analyzer coupled to a quadrupole mass spectrometer for evolved gas analysis. By heating non-isothermally different initial amounts of NiAc (100–400 mg) in an argon flow at 10 °C/min from room temperature to 500 °C, CENiNPs were readily obtained, in which a thin layer of carbon resulting from the breakdown of the anion protects their metallic core from spontaneous oxidation. High resolution transmission electron microscopy and methane catalytic decomposition tests revealed that this encapsulating layer can also exert a significant role in the control of the size distribution (40–140 nm) and catalytic activity of the resultant CENiNPs. Temperature programmed oxidation of the CENiNPs identified preliminary some surface carbon species responsible for the packing of the catalytically-active metallic core. This simple and cost-effective method emerges as a competitive way to manufacture and conserve highly active CENiNPs.

    更新日期:2017-12-31
  • Pyrolysis Characteristics of Tobacco Stem after Different Solvent Leaching Treatments
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-29
    Zhenguo Chen, Erwei Leng, Yang Zhang, Anqing Zheng, Yang Peng, Xun Gong, Yuqian Huang, Yu Qiao

    The considerable amounts of alkaloids in tobacco stem (TS) make it wasteful and environmentally detrimental to directly pyrolyze it. This paper reveals the effects of leaching treatments with different solvents (hydrochloric acid, water and ethyl alcohol) on the pyrolysis characteristics of TS using TG-FTIR and Py-GC-MS. Alkaloids mainly consisting of nicotine were almost completely removed by leaching treatments, leading to the reduction of the N content in treated samples and the reduction of N-containing compounds in the obtained tar by Py-GC-MS. Potassium and calcium, which are the two main cations in TS, were removed completely by acid leaching, whereas calcium is resistant to water and alcohol. The removal of inorganic species in leached samples reduced the stability of TS at low temperatures ( < ∼ 270 °C) but improved it at high temperatures (270–490 °C). In addition, more sugars, such as levoglucosan, and high-mass weight species were generated by pyrolysis of TS leached by several solvents, especially acid. Different from water and alcohol, hydrochloric acid strongly destroyed the matrix structure of TS and lowered its thermal stability. Because of the removal of acid-soluble lignin by hydrochloric acid, the generation of benzenes during pyrolysis were markedly inhibited.

    更新日期:2017-12-31
  • Intermediate products characterization and thermal decomposition mechanism of potassium tetraoxalate during in – situ synthesis of potassium carbonate
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-29
    Naina Raje, Bhupesh B. Kalekar, Darshana K. Ghonge

    Current studies describe the application of simultaneous TG–DTA–FTIR techniques in the in-situ synthesis of potassium carbonate (K2CO3) from the thermal decomposition of potassium tetraoxalate dihydrate [KH3(C2O4)2.2H2O]. Progress of the decomposition reactions with increasing temperatures was monitored online through TG mass loss, corresponding heat effects and evolved gases. Sequential formation of anhydrous potassium tetraoxalate, potassium hydrogen oxalate [KHC2O4] and potassium oxalate [K2C2O4] was confirmed using thermal, ATR − FTIR and PXRD measurements. The intermediate potassium oxalate undergoes structural transformation and then decomposes to potassium carbonate by the temperature of 600 °C. PXRD measurements confirm the formation of K2CO3 and the results are in agreement with ATR − FTIR and thermal analysis.

    更新日期:2017-12-31
  • Comparison of Catalytic performance of an Iron-alumina pillared montmorillonite and HZSM-5 zeolite on a Spouted Bed Reactor
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-29
    E. Borsella, R. Aguado, A. De Stefanis, M. Olazar

    Catalytic pyrolysis of high density polyethylene (HDPE) on HZSM-5 catalyst and an iron-alumina pillared montmorillonite, prepared in laboratory (FAMO), was performed by means of a conical spouted bed reactor. This type of reactor is a suitable technology for plastic pyrolysis due to its high heat and mass transfer rates and excellent performance in the handling of sticky solid materials. The pyrolytic process carried out on HZSM-5 catalyst gave significant yield of gaseous products (above 74 wt%), while FAMO catalyst gave high yields of waxes, particularly rich in diesel hydrocarbon range (C11-C21). Waxes obtained by subjecting HDPE to thermal pyrolysis had a higher range of molecular weight. Waxes have been characterised using different techniques, such as gel permeation chromatography (GPC), polidispersity (PD), Fourier transform infrared (FTIR) spectroscopy, Simulated Distillation, and TDP.

    更新日期:2017-12-31
  • The emission of gaseous nitrogen compounds during pyrolysis of meat and bone meal
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-28
    Yuheng Feng, Lu Wan, Shengjie Wang, Tianchi Yu, Dezhen Chen

    Pyrolysis is a clean and economical method to dispose meat and bone meal (MBM) from animal carcasses. However, the large quantity of nitrogen from the animal protein will lead to the formation of gaseous-N compounds such as NH3 and HCN, which are the precursors of NOx. In this study, the release behavior of these gaseous-N compounds during the pyrolysis of MBM was investigated using a temperature-programed tube reactor combined with an FTIR analyzer. Moreover, the formation mechanism of them was elucidated by examining the evolution of solid and liquid N-products with temperature. The result showed that 31.0% of the MBM was released as gaseous N including NH3, HCN and HNCO, among which NH3 accounted for 76.2% while HNCO was a minor product. NH3 was mainly released below 300 °C from the decomposition of ammonium and the polymerization of liable protein. On the other side, the nitriles and heterocyclic N-compounds identified in tar and char were the precursors of HCN and HNCO. The results provided basic data for the inhibition and removal of gaseous N-compounds during the pyrolysis of animal biomass.

    更新日期:2017-12-31
  • Pyrolysis characteristic and mechanism of waste tyre: a thermogravimetry-mass spectrometry analysis
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-28
    Jun Han, Wei Li, Dongyi Liu, Linbo Qin, Wangsheng Chen, Futang Xing

    In this study, waste tyre pyrolysis characteristic was investigated by a thermogravimetric analyzer combined with a mass spectrometer (MS). At the same time, the functional groups at the surface of residue char were also characterized by a Fourier-transform infrared (FTIR) spectrometer. The main components of the gas evolved from tyre pyrolysis process were H2O, CO, CO2, and hydrocarbon. According to MS and thermogravimetric (TG) curves, tyre pyrolysis could be divided into four stages. The first stage was due to water vaporization and plasticizer decomposition at the temperature below 320 °C. The secondary stage was attributed to natural rubber decomposition at 320–400 °C, and the third stage was related to the decomposition of synthetic rubber, which took place at 400–520 °C. The fourth stage was occurred above 520 °C. The variation of the functional groups on the residue char analyzed by FTIR also proved the above assumption.

    更新日期:2017-12-31
  • Effect of particle of HZSM-5 zeolite on the catalytic depolymerization of organosolv lignin to phenols
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-27
    Xing Wang, Boyu Du, Lei Pu, Yanzhu Guo, Haiming Li, Jinghui Zhou

    The effect of particle on the catalytic activity of HZSM-5 zeolite in organosolv lignin to phenols was investigated in the supercritical ethanol-water under the operating conditions of 350 °C and 4 h. Two samples comprising a micro and a nano size HZSM-5 were prepared by reflux and hydrothermal crystallization method, respectively. The catalyst samples were characterized with XRD, SEM, BET and NH3-TPD analytical techniques. The effect of crystal size on the lignin conversion to phenols and the structure changes of lignin residue were studied. The nano-HZSM-5 showed higher yield of phenols and lower yield of char as compared to the micro-HZSM-5. The enhanced content of aromatic C-C structures and extenuative content of aromatic C-O and C-H showed that intramolecular dehydration and deoxygenation were occurred with nano- and micro-HZSM-5, and the nano-HZSM-5 activity significantly stronger than micro-HZSM-5.

    更新日期:2017-12-27
  • Thermal and catalytic micropyrolysis for conversion of cottonseed oil dregs to produce biokerosene
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-26
    Tarciane Greyci dos Santos Souza, Brenda Lohanny Passos Santos, Ayrla Murielly Alves Santos, Anne Michelle Garrido Pedrosa de Souza, James Correira de Melo, Alberto Wisniewski Jr

    A sample of cottonseed oil dregs was obtained by the alkali pretreatment of the oil to remove free fatty acids and other impurities before an industrial biodiesel production process. The alkali dregs was characterized and submitted to non-catalytic, catalytic, and reactive hydrogen atmosphere micropyrolysis experiments to assess the capacities for type SPK–HEFA biokerosene production. Non-catalytic and catalytic micropyrolyses were performed at 500 and 550 °C. In the catalytic experiments, catalysts based on Mo or W oxides supported on Zr or Ti oxides were tested for the first time for this purpose. The moisture content of the cottonseed oil dregs was 23.4% (wt%) and the other major components were triacylglycerols + free fatty acids (65.0%) and inorganic material (9.8%). The products of the micropyrolysis experiments were characterized by GC-MS and quantified by GC-FID. The presence of moisture in the initial feedstock provided better results in the thermal conversion to liquid biofuel (16%), compared to dry biomass (6%), considering the n-alkanes and n-alkenes produced in the range C9–C16. The mass conversion performed in the presence of catalysts at 550 °C resulted in an average yield of around 32%, compared to a value of 19% for a non-catalytic process under a nitrogen atmosphere, with the same values for the yields under a reactive hydrogen atmosphere. The reactive atmosphere and the catalysts did not have any substantial influence on the ratio between n-alkanes and n-alkenes.

    更新日期:2017-12-27
  • Pyrolysis of organic ester cured alkaline phenolic resin: identification of products
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-26
    Angelika Kmita, Aleksandra Benko, Agnieszka Roczniak, Aneta Frączek-Szczypta, Mariusz Holtzer

    Increased application of organic compounds, mainly in form of synthetic resins, used as binders for moulding and core sands in metal casting, may have an adverse effect on the environment and work conditions in foundry plants. In this article we focused on the identification of the degradation products formed during laboratory scale simulation of complex thermal degradation of commercial binder. For our investigation we have chosen the phenol-formaldehyde based resin hardened by a mixture of organic esters (PFRE) as it is widely used in the core and mould sand technology. The identified degradation products obtained during the experiments varied depending on mechanism used for pyrolysis. In the “slow” evaluation, simple compounds such as: CO, CO2, NH3, H2O, phenol and CH4 were generated. Meanwhile, during the “flash” pyrolysis (500, 700, 900 and 1100 °C), mainly phenol and its methyl and ethyl derivatives as well as benzene were released. It was determined that the pyrolysis products and their ratio depended on the temperature during the degradation process.

    更新日期:2017-12-27
  • Thermochemical decomposition of coffee ground residues: a kinetic study
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-24
    Javier Fermoso, Ondřej Mašek

    A thermogravimetric analyser coupled to a mass spectrometer, for evolved gas analysis, were employed to perform pyrolysis tests at heating rates (5–100 °C/min) and at maximum temperature of 500 °C to determine kinetic parameters of thermochemical decomposition of the biopolymers comprising coffee ground residues. During the pyrolysis process, the maximum decomposition rate of each biomass component increased linearly with the heating rate used. The slope increased with the biopolymer reactivity in the following sequence: hemicellulose > celluose > lignin. Accordingly, kinetic parameters for any of these individual biopolymers in CGR were estimated using the model-free isoconversional dynamic methods Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) models. The average value for the apparent activation energy of the individual biopolymers (hemicellulose, cellulose and lignin) in CGR calculated by KAS and FWO methods were estimated as 214, 241 and 266 kJ/mol, respectively; whilst for the CGR as a whole it was 242 kJ/mol. The two model-free isoconversional dynamic methods have been shown to be useful tools for assessment of biomass pyrolysis kinetic parameters, as they can provide Ea values for use in reactor design models.

    更新日期:2017-12-27
  • Coupling of an acoustic emissions system to a laboratory torrefaction reactor
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-23
    Edgar A. Silveira, Marcus Vinícius Girão de Morais, Patrick Rousset, Armando Caldeira-Pires, Anélie Pétrissans, Luiz Gustavo Oliveira Galvão

    This article describes the use and characterization of an acoustic system coupled to a torrefaction reactor. The reactor, including phase shift and frequency, was characterized by applying both Lissajous/Hilbert and cross-spectrum techniques. Optimum acoustic frequencies were identified and an exploratory torrefaction test combining frequencies and temperatures was performed. The results from dynamic solid yields, conversion rates and temperature profiles showed that acoustic fields may improve torrefaction treatment.

    更新日期:2017-12-27
  • Valorization of coffee silverskin industrial waste by pyrolysis: from optimization of bio-oil production to chemical characterization by GC × GC/qMS
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-13
    Allan dos Santos Polidoro, Enelise Scapin, Eliane Lazzari, Aline Nunes Silva, Anaí Loreiro dos Santos, Elina Bastos Caramão, Rosângela Assis Jacques
    更新日期:2017-12-14
  • Cement catalyzed conversion of biomass into upgraded bio-oil through Microwave metal interaction Pyrolysis in aluminum coil reactor
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-12
    Khadim Hussain, Nadia Bashir, Zahid Hussain, Shaharin Anwar Sulaiman

    Metal objects spark in the microwaves, exposing metals to melting point temperatures. The resulting heat can be utilized for the pyrolysis of biomass into upgraded bio oil. In this work pyrolysis was carried out both in the presence and absence of catalyst and the upgradation of bio oil was found the combine action of microwave heating, microwave effects and the catalytic activity of cement. Catalytic pyrolysis of biomass was carried out by mixing powdered biomass with fine powder of cement and placing the resulting mixture in an aluminum coil located in the baked clay reactor followed by its exposure to the microwaves. In this process aluminum coil was used as microwave receiving and heat generating antenna. All these experiments were carried out in a modified domestic microwave oven. The amount of product fractions like bio-oil, biogas and biochar was determined in terms of the mass of catalyst, time of reaction and the gauge of aluminum wire used for the preparation of coil. The bio oil obtained under the optimum conditions was analyzed using Gas chromatography mass spectrometry and the gaseous product was analyzed using chemical tests. Significant difference was observed in the chemical composition of bio oils prepared by catalytic and non-catalytic processes. Further, the oxygen contents of both types of the bio oil were found less than those to be obtained by conventional pyrolysis.

    更新日期:2017-12-14
  • Catalytic fast pyrolysis of cellulose to produce furan compounds with SAPO type catalysts
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-10
    Xu Chen, Yingquan Chen, Zhen Chen, Danchen Zhu, Haiping Yang, Peng Liu, Tao Li, Hanping Chen
    更新日期:2017-12-14
  • Pyrolytic behaviors of decocting residues of Rhodiola rosea
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-06
    Tipeng Wang, Li Peng, Yinong Ai, Runhe Zhang, Qiang Lu

    Pyrolysis behaviors of decocting residues of Rhodiola rosea (RR) were studied by TGA and Py-GC/MS. Results indicated that with an increase of decocting time from 0 to 4 h, the contents of extractives and hemicellulose decreased from 29.15 and 5.35 wt.% to 28.18 and 3.47 wt.%, respectively, the contents of acid-insoluble lignin increased from 43.81 to 46.58 wt.%; the content change of cellulose was small. Pyrolysis processes of RR mainly occurred in seven stages and independent weight loss of lignin were found at 380–800 °C, which suggested that RR could be a perfect material to study the lignin structure. The effects of decocting time on the pyrolysis behaviors of RR were slight, mainly changing the pyrolysis progress of extractives and hemicellulose and enhancing the Activation Energy at stage3 from 96 to 110 kJ/mol. In RR pyrolysis, low pyrolysis temperature (for example 300 °C) was propitious to the formation of sugars and furans; high temperature (for example 500 °C) could be contributed to enhance the contents of linear ketones; however, moderate temperature (for example 400 °C) could be a better choice to product the linear acids and phenols. 15.44% content of 1, 6-anhydro-β-d-glucopyranose in the bio-oil at 300 °C suggested good pyrolysis selectivity of RR. Decocting treatment changed the product distributions in the bio-oil. The contents of linear ketones increased remarkably from 13.34 to 25.35% and the contents of sugars and furans decreased from 8.06 and 7.02% to 6.33 and 2.46%, respectively.

    更新日期:2017-12-14
  • Thermoplastic development of coking and non-coking maceral concentrates and molecular weight distribution of their pyrolysis products
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-06
    Quang Anh Tran, Rohan Stanger, Wei Xie, Nathan Smith, John Lucas, Terry Wall

    A suit of nitrogen-dried maceral concentrates derived from a coking coal and a non-coking coal was investigated to reveal the impact of varying coal main organic constituent, the vitrinite, on their thermoplasticity and pyrolysis products. The thermoplastic development of maceral concentrates during pyrolysis was evaluated via their thermo-swelling and dynamic volatile release. These measurements were then linked to molecular weight distributions of vaporised tars and tetrahydrofuran (THF) extracts obtained from heat-treated samples. Regardless of the vitrinite content, only coking macerals agglomerated during pyrolysis while non-coking macerals retained their powdered structure. This result indicated that although concentrating the vitrinite could alter the extent of coal thermoplasticity, such process could not grant or remove thermoplasticity from a maceral concentrate. This was reflected in the similar molecular weight distribution of solvent extracts produced between the parent coals and their concentrates. In specific, coking concentrates generated extractable materials with a relatively more complex structure, consisting of a bimodal molecular weight distribution with 12–14 Da repeating structures at <600 Da and 24 Da reoccurring units between 600 and ∼1500 Da. Solvent extracts isolated from non-coking concentrates, on the other hand, possessed a unimodal molecular weight distribution with only 12–14 Da repeating structures extending to ∼800 Da. The absence of high-range molecular weight materials (the 24 Da repeating units) in non-coking coal and its concentrates was speculated to play a vital role to their inability to exhibit thermoplastic behaviour during pyrolysis.

    更新日期:2017-12-14
  • Light olefin production from catalytic pyrolysis of waste tires using nano-HZSM-5/γ-Al2O3 catalysts
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-05
    Zhuangzhang He, Qingze Jiao, Zhuqing Fang, Taotao Li, Caihong Feng, Hansheng Li, Yun Zhao
    更新日期:2017-12-14
  • Properties and pyrolysis behavior of moso bamboo sawdust after microwave-assisted acid pretreatment
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-02
    Yunpu Wang, Dengle Duan, Yuhuan Liu, Roger Ruan, Guiming Fu, Leilei Dai, Yue Zhou, Zhenting Yu, Qiuhao Wu, Zihong Zeng

    The effects of microwave-assisted acid pretreatment on the characteristics and pyrolysis behavior of moso bamboo sawdust (BS) were investigated by ultimate, Fourier transform infrared spectroscopy, thermogravimetric (TG), and pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS) analyses in this study. Microwave temperature (100 °C–200 °C), reaction time (30 min–90 min), and acid concentration (0.5 M–1.5 M) were the main influencing factors. Results of ultimate analysis indicated that the properties of the pretreated samples are better than those of the raw BS. Moreover, appropriately reducing the oxygen and ash contents and increasing the microwave temperature promoted decarboxylation and dehydration during pretreatment. Microwave-assisted acid pretreatment decreased the acetyl groups and hydrogen bonds. Of the three main influencing factors affecting the structure of moso BS, microwave temperature was the most important. TG analysis results indicated that the thermostability of the pretreated samples is improved after pretreatment. Moreover, the pyrolysis behavior of moso BS is insensitive to the reaction time and acid concentration under mild conditions. The relative contents of acids, furans, aldehydes, and ketones derived from the pretreated samples decreased according to the results of Py-GC/MS. Meanwhile, the relative glucopyranose and phenol contents of the pretreated samples are higher than those of the raw moso BS and achieve the maximum values of 48.31% and 20.18%, respectively, at 200 °C.

    更新日期:2017-12-14
  • Effects of torrefaction temperature and acid pretreatment on the yield and quality of fast pyrolysis bio-oil from rice straw
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-12-02
    Suchada Ukaew, Jacob Schoenborn, Bethany Klemetsrud, David R. Shonnard

    This study investigated the effects of torrefaction temperatures and dilute acid pretreatment on the quality of pyrolysis bio-oil and the distribution toward gaseous, liquid bio-oil, and char products from rice straw. Torrefaction of rice straw was conducted at different temperatures (225 °C, 250 °C, and 275 °C) for 30 minutes in a Py-GC/MS reactor. After the torrefaction process was completed, fast pyrolysis of torrefied rice straw was then performed at temperatures of 450 °C, 500 °C and 550 °C with a heating rate of 1000 °C/s and held for 20 seconds in the same micropyrolysis reactor. The results showed that the decrease of pyrolysis bio-oil, gas, and water, are observed when the torrefaction temperature increases. However, the decreasing trend of pyrolysis char yield was observed when the torrefaction severity increases at pyrolysis temperatures 450 °C and 500 °C, but an increasing trend was noticeable at pyrolysis temperature 550 °C. The phenolic components in pyrolysis bio-oil from torrefied rice straw were lower compare to raw rice straw. The torrefaction process helps improve the quality of pyrolysis bio-oil in terms of reducing some water, acid, and oxygenated species. The torrefaction temperature of 225 °C with the pyrolysis temperature of 550 °C is indicated as the optimum condition in our study. Additionally, the removal of mineral content from rice straw promoted higher yields of pyrolysis bio-oil, particularly levoglucosan. The acid pretreatment method also improved the pyrolysis product distribution in terms of enhancing bio-oil yield and reducing water, gas, and char.

    更新日期:2017-12-14
  • Application of Py-GC/MS coupled with PARAFAC2 and PLS-DA to study fast pyrolysis of genetically engineered poplars
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-28
    Hilal E. Toraman, Victor Abrahamsson, Ruben Vanholme, Rebecca Van Acker, Frederik Ronsse, Gilles Pilate, Wout Boerjan, Kevin M. Van Geem, Guy B. Marin

    Field-grown genetically engineered and wild-type poplars were pyrolyzed in a micro-pyrolysis (Py-GC/MS) setup under fast pyrolysis conditions. Poplars (Populus tremula x P. alba) down-regulated for cinnamoyl-CoA reductase (CCR), which catalyzes the first step of the monolignol-specific branch of the phenylpropanoid biosynthetic pathway, were grown in field trials in France and harvested after a full rotation of 2 years. The effect of small compositional differences, specifically small shifts in lignin composition and their impact on the bio-oil composition, could not be identified using principal component analysis (PCA), necessitating the use of more advanced analysis techniques. The combination of parallel factor analysis 2 (PARAFAC2) and partial least squares-discriminant analysis (PLS-DA) for detailed characterization and classification of the pyrolysis data enabled the classification of the poplars with a success rate above 99% using the PARAFAC2 scores. This methodology proved to be extremely valuable to identify subtle information in complex datasets, such as the one used in this study. The obtained PLS-DA models were validated by cross-validation, jackknifing and permutation tests in order to ensure that the model was not overfitting the data. PLS-DA showed that down-regulation of CCR disfavored the relative amount of both guaiacyl and syringyl lignin-derived compounds. This study shows that lignin engineering can be a promising strategy to alter the lignin composition of the biomass for the production of high value-added phenolic compounds.

    更新日期:2017-12-14
  • Microwave pyrolysis of sewage biosolids: Dielectric properties, microwave susceptor role and its impact on biochar properties
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-28
    Elsa Antunes, Mohan V. Jacob, Graham Brodie, Philip A. Schneider

    Microwave assisted pyrolysis (MWAP) is an alternative heating approach to convert biosolids into value-added products, such as biochar, biogas and bio-oil. Studying the dielectric properties of biosolids is fundamental to understand the behaviour of this material under microwave irradiation and to design microwave assisted pyrolysis systems. This study examined the dielectric properties of biosolids with changes in moisture content and applied microwave frequency. Results demonstrated that the dielectric constant decreases with decreasing moisture content and with increasing microwave frequency, but the dielectric loss factor of dry biosolids is almost zero. Simulations demonstrated that moisture content of biosolids impacts on the distribution and intensity of electromagnetic field. Because of the poor dielectric properties of dry biosolids, a microwave susceptor must be added to the biosolids to attract microwave energy so that the materials can reach temperatures required for pyrolysis. Therefore, this study also investigated the impact of four microwave susceptors (activated carbon, charcoal, biochar and glycerol) on biosolids pyrolysis and on biochar properties produced from biosolids via microwave assisted pyrolysis at 600 °C. The choice of microwave susceptor influences the heating rate of biosolids and the specific surface area of the resultant biochar. Results show that activated carbon favours the heating process, increases surface area, and the biochar produced with activated carbon has the highest carbon stability and energy value.

    更新日期:2017-12-14
  • A comparison between the characteristics of single- and mixed-feedstock biochars generated from wheat straw and basalt
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-27
    Sarasadat Taherymoosavi, Stephen Joseph, Ben Pace, Paul Munroe

    Mixed-feedstock-biochars can increase both available soil organic matter (SOM) and inorganic nutrients, yielding a more valuable biochar for agricultural purposes. Since the agronomic benefits of biochar are dependent on its structural and physio-chemical characteristics, this study compares these properties for single- and mixed-feedstock-biochars using a range of analytical techniques. Six biochars were produced from wheat straw (Ws), and a combination of wheat straw and basalt (WsBs) at three pyrolysis temperatures, 450, 550 and 650 °C. The results showed that WsBs biochars contained higher ash contents, with considerably lower fixed carbon, volatile matter and electrical conductivity than the Ws biochars. Microscopic and spectroscopic analyses revealed increases in the concentration of Si on the surface of wheat straw particles during processing. A layer of Si on the surface of the C matrix appeared to prevent further reactions between C-rich phases and some mineral phases (mainly Fe and Ca-rich regions) at 650 °C. Other mineral compounds, such as those rich in K and Na, were adsorbed to both C and Si-rich phases. Basalt incorporation into the wheat straw particles also catalysed new functionalities. Surface C-N-based functionalities (amides) were only detected in wheat straw biochars, whereas ammonium-based groups were found in the WsBs biochars. Concentrations of dissolved organic carbon, which were affected by both feedstock composition and pyrolysis temperature, appeared to be higher in the Ws biochars, with the highest concentrations found at 450 °C. The WsBs biochars contained greater concentrations of biopolymers and humic-like substances than the Ws biochars. These organic fractions would increase the availability of micro-nutrients, reduce ions leaching and promote soil strength and resistance to erosion following the biochar application.

    更新日期:2017-12-14
  • Operating parameters for bio-oil production in biomass pyrolysis: A review
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-26
    Raquel Escrivani Guedes, Aderval S. Luna, Alexandre Rodrigues Torres
    更新日期:2017-12-14
  • Analysis of the asphaltene properties of heavy crude oil under ultrasonic and microwave irradiation
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-22
    Jaber Taheri-Shakib, Ali Shekarifard, Hassan Naderi

    Using new technologies are quite significant in the production and development of heavy oil reservoirs. In this study, the effects of microwave (MW) and ultrasonic (US) waves on the properties of Ellam heavy crude oil of the southwest oil reservoirs of Iran have been investigated. Experimental results show that different processes occur in samples under MW radiation for 5, 10, 15 and 20 min. Under MW for 5 and 10 min we have viscosity reductions from 15.836 mPa.s to 12.234 mPa.s and 11.122 mPa.s, respectively. This is due to volume expansion with decreasing viscosifying component and high absorption capacity of heavy molecules of oil toward MW that charges the cracking process. US waves increase the viscosity of oil for all time durations because the power from US waves causes the evaporation of light compounds. Next, the effect of MW and US radiation on the asphaltene clusters using microscopic images was investigated. Results of asphaltene particle size distribution show that increasing duration of wave radiation makes the particles smaller, and the size range of asphaltene particles in the samples under MW radiation is much smaller than for the samples under US wave radiation. Moreover, in samples under MW radiation, the large particles cannot be seen. Consequently, the average particle size of asphaltene is smaller in samples under US wave radiation. But the particle size range is high, and large-sized particles in different time intervals of US radiation are observed. The results of scanning electron microscopy show that microwaves make the asphaltene conglomerate forming particles smaller and more regular in shape than the primary state, whereas ultrasonic waves completely alter the structure of the asphaltene particles, creating asphaltene clusters with a different structure. Based on the Fourier transform infrared spectra, ultrasonic exposure increases the cracking rate of the weaker bands and the condensation of aliphatic bands more than does exposure to microwaves, due to an increase in the intensity of the spectra.

    更新日期:2017-12-14
  • Co-pyrolysis and co-hydrothermal liquefaction of seaweeds and rice husk: Comparative study towards enhanced biofuel production
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-21
    Yamin Hu, Shuang Wang, Jiancheng Li, Qian Wang, Zhixia He, Yongqiang Feng, Abd El-Fatah Abomohra, Stephen Afonaa-Mensah, Chiwai Hui

    The production of bio-oil and bio-char by fast pyrolysis and hydrothermal liquefaction of Enteromorpha clathrata, rice husk and their mixtures have been compared. The results indicated that hydrothermal liquefaction produced higher yield of bio-oil and lower yield of bio-char for the same raw samples. There were more macromolecules (hexadecanoic acid, cyclopenten and esters), small-molecule hydrocarbons and N-containing compounds in hydrothermal liquefaction bio-oil, while more aromatic substances were observed in fast pyrolysis bio-oils. There was significant difference between E. clathrata bio-oils from these two thermochemical methods CO, CH/CH2/CH3 and NH functional groups in E. clathrata bio-oil from hydrothermal liquefaction showed stronger absorption strength than bio-oil from fast pyrolysis. However, the only difference between rice husk bio-oil from hydrothermal liquefaction and fast pyrolysis was aromatic ring signal in Fourier transform infrared spectroscopy curves. In addition, synergistic effect was investigated during the co-pyrolysis and co-hydrothermal processes. Such synergistic effect led to the improvement recorded in the bio-oil quality by deoxidation reaction to increase the H/C ratio in bio-oil from co-pyrolysis of E. clathrata/rice husk blends, and reduces the O/C ratio in bio-oil from co-hydrothermal process, and also enhances the calorie value of bio-oil. The synergistic effect, however, lowered the co-pyrolysis and co-hydrothermal bio-oils yields. Moreover, the addition of rice husk into E. clathrata promoted the bio-oil conversion efficiency of protein and increased the content of aromatic substances.

    更新日期:2017-12-14
  • Co-carbonization behaviors of petroleum pitch/waste SBS: Influence on morphology and structure of resultant cokes
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-21
    Youliang Cheng, Qingling Zhang, Changqing Fang, Yun Ouyang, Jing Chen, Xin Yu, Donghong Liu

    Petroleum pitch was modified by waste styrene-butadiene-styrene copolymer (SBS) and the cokes were obtained via the co-carbonization method. The waste SBS content and the co-carbonization temperature have important effects on the morphology and structure of resultant cokes. It can be found that adding waste SBS can obviously increase the methylene content in the cokes and improve the thermal stability of the co-carbonized products. The coke of MP7.5-450-10 exhibits almost 100 vol% anisotropy region with streamline texture and has the lowest weight loss of 5 wt%. The coke of MP10-450-10-C has the smallest carbon interlayer space and the largest crystallite thickness. Co-carbonized products at 900 °C have the porous structure similar with carbon foam, and the large pore diameter is in the range of 200–1000 μm. Importantly, there are some mesopores existing in the products. Moreover, adding waste SBS can increase the specific surface area and the pore volume of carbonized products. The samples of MP7.5-450-10-C has some mesopores with the diameter of 3–50 nm, and the pore volume is 0.013 cm3 g−1.

    更新日期:2017-12-14
  • Fabrication and formation mechanism of carbon foam with two-level cell structure
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-21
    Qiyun Zhang, Yixuan Mu, Qilang Lin, Yangfa Chen, Changqing Fang, Lei Xiong

    A novel method was developed for production of carbon foam with two-level cell structure, which possesses two kinds of cell sizes of about 1 μm and 300 μm. Results show a carbothermal reduction occurs between the pore wall of first-level foam and the nano-MgO at high temperatures, which results in further bubbling and forming the second-level foam. The carbon foam prepared exhibits a characteristic of pseudoplastic deformation with a relatively compressive strength of 1.72 MPa, and possesses a low bulk density of 0.11 g/cm3 and a high porosity of 94.2%.

    更新日期:2017-12-14
  • Thermal degradation of Polylactide/Poly(ethylene glycol) fibers and composite fibers involving organoclay
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-21
    Esra Ozdemir, Jale Hacaloglu

    In this study, electrospun fibers of melt blended poly(lactic acid) and poly(ethylene glycol), (PLA)-PEG blends involving 10, 15 and 20 wt% PEG and their corresponding composites with organically modified montmorillonite, Cloisite 30B were prepared and characterized by x-ray diffraction, differential scanning calorimetry, thermogravimetry and direct pyrolysis mass spectrometry techniques. The narrower fiber diameters observed for the PLA-PEG fibers involving organoclay compared to the corresponding neat fibers were associated with the presence of quaternary ammonium salt as organic modifier increasing electrical conductivity. Strong evidence for phase separation during the electrospinning process was detected for PLA-PEG fibers. On the other hand, for PLA-PEG composite fibers, as a consequence of the diffusion of both PLA and PEG chains from the bulk polymer into the galleries between the silicate layers of the organoclay, the interactions between PLA and PEG chains were enhanced and both components showed similar thermal characteristics, indicating lack of phase separation. These interactions further inhibited the interactions between the PLA chains and organic modifier of the organoclay

    更新日期:2017-12-14
  • Research on the thermal behavior of novel heat resistance explosive 5,5′-bis(2,4,6-trinitrophenyl)-2,2′-bi(1,3,4-oxadiazole)
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-20
    Jing Zhou, Li Ding, Fuqiang Bi, Bozhou Wang, Junlin Zhang

    5,5′-bis(2,4,6-trinitrophenyl)-2,2′-bi(1,3,4-oxadiazole) (TKX-55) was synthesized through an oxidation-chloridization-condensation-cyclization sequence. Thermal decomposition behavior and non-isothermal decomposition reaction kinetics of TKX-55 were investigated by the differential scanning calorimetry and thermogravimetric analysis (DSC-TG) methods The research of decomposition mechanism of the molecule was further carried out through in-situ FTIR spectroscopy technologies. The experiment results showed that the enlarged conjugated system has a marked effect on the thermal stability and the picryl moiety is much more stable than the 1,3,4-oxadiazole moiety during the heat-up process, indicating that the decomposition process is mostly likely to initiate from the ring-opening reaction of 1,3,4-oxadiazole moiety which is supported by the computational scanning result of potential energy surface.

    更新日期:2017-12-14
  • Catalytic co-pyrolysis of switchgrass and polyethylene over HZSM-5: Catalyst deactivation and coke formation
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-15
    Charles A. Mullen, Christina Dorado, Akwasi A. Boateng

    Conducted in the presence of a zeolite catalyst such as HZSM-5, fast pyrolysis of biomass can promote the rejection of oxygen and the formation of aromatic hydrocarbons in the organic liquid products. Unfortunately, this pathway removes hydrogen from the already hydrogen deficient biomass starting material, limiting the yield of hydrocarbons and leading to coke formation which results in catalyst deactivation. Co-pyrolysis of biomass and a low cost hydrogen rich material such as waste plastic has been considered as one strategy for mitigating hydrogen-deficiency with an added benefit of disposing of waste plastics effectively. Previous work has shown an enhancement of aromatic yields when polyolefins were copyrolyzed with biomass over fresh HZSM-5, but studies on the effect of catalyst deactivation with repeated use of the catalyst are lacking. In this study, pyrolysis coupled with gas chromatography and mass spectrometry (py-GC/MS) with an external catalytic reactor was used to perform ex situ catalytic co-pyrolysis of switchgrass and polyethylene (1:1 w:w) in the presence of HZSM-5. The catalyst (∼15 mg) was exposed to ∼1 mg biomass and/or plastic in a series of 30 or 60 pulsed experiments for a cumulative feedstock to catalyst ratio of 2:1 and 4:1, respectively. Results showed that the initial rate of catalyst deactivation (up to feed:catalyst 2:1), as measured by the decrease in production of aromatic hydrocarbons, was significantly decreased, estimated at only ∼28% of the rate of deactivation that processing of switchgrass alone caused. However, over the continued use of the catalyst, up to a feed to catalyst ratio of 4:1, the rates of deactivation from the blended feedstock increased to near expected rates based on the rate of deactivation for the switchgrass and HDPE individually.

    更新日期:2017-12-14
  • Pyrolytic-deoxygenation of triglycerides model compound and non-edible oil to hydrocarbons over SiO2-Al2O3 supported NiO-CaO catalysts
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-15
    N. Asikin-Mijan, H.V. Lee, T.S. Marliza, Y.H. Taufiq-Yap

    Catalytic deoxygenation (DO) of triglycerides-based feeds to diesel-like fuel was investigated over NiO-CaO/SiO2-Al2O3 and NiO/SiO2-Al2O3 catalysts using semi-batch reactor under partial vacuum and inert N2 flow. The results showed that the bi-functional catalyst exhibited the highest DO activity with product selectivity toward diesel-like fuel n-(C13–C20). The catalytic process appeared to inhibit the occurrence of side reactions via neutralization of the strong acid sites. On the other hand, DO reaction under inert N2 flow has improved the deoxygenated product, which demonstrate that N2 flow condition has effectively removed the decarboxylation/decarbonylation gasses (CO2/CO) from poisoning the catalyst active sites. The high concentration of strong basic-acid sites of the catalyst is the main reason for increased CC cleavage pathway, while milder acidic sites responsible for CO cleavage pathway. High degree of unsaturated fatty acid in the feedstock has affected adversely the DO of triglycerides by accelerating the catalyst deactivation. The N2 flow condition, degree of unsaturated fatty acid in the feedstocks, acidity and basicity of the catalysts are important factors to improve DO activity as well as product selectivity.

    更新日期:2017-12-14
  • Thermal decomposition study of some polyimide-polydimethylsiloxane copolymers
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-13
    Corneliu Hamciuc, Gabriela Lisa, Elena Hamciuc, Nita Tudorachi

    This study presents the evaluation of thermal and thermo-oxidative stability of some polyimide-polydimethylsiloxane (PI-PDMS) copolymers and establishes the thermal degradation mechanism by simultaneous mass spectrometry and Fourier transform infrared spectroscopy of gas products from thermogravimetric analyzer (TG/MS/FTIR) in two working atmospheres: air and He. The thermal stability and the start mechanism of thermal degradation were correlated with the chemical structure of PI-PDMS and the working atmosphere. The main thermal decomposition products were determined in both oxidative and inert atmosphere.

    更新日期:2017-12-14
  • Carbohydrate composition in Eucalyptus wood and pulps – Comparison between Py-GC/MS and acid hydrolysis
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-13
    T. Ohra-aho, F.J.B. Gomes, J.L. Colodette, T. Tamminen

    In analytical pyrolysis, carbohydrates are degraded into stable anhydrosugars, which are analyzed by GC/MS. The benefit of Py-GC/MS is that fiber composition including carbohydrates, lignin and its S/G ratio can be determined simultaneously from fiber-based materials without need of extensive pretreatment, contrary to the traditional method. In this study, the relative carbohydrate composition of various Eucalyptus species was determined by Py-GC/MS. In addition, pulps produced from the same species by soda-AQ and soda-O2 processes were analyzed similarly. The results were compared with those obtained by acid hydrolysis followed by HPLC. This comparison showed that the relative carbohydrate composition determined by Py-GC/MS for the wood samples differed from the values obtained by acid hydrolysis. Significantly better correlation between the two methods was observed for the pulp samples cooked to varying kappa number levels. Fractionated pyrolysis was applied in order to find explanation to the observed difference in the degradation behavior of carbohydrates in wood and pulp samples. Due to the close association of lignin and carbohydrates, the thermal behavior of lignin was followed as well. The results showed that the thermal behavior of xylan and cellulose differed in the wood samples, but were almost equal in the pulp samples. Thermal degradation of xylan was similar with lignin in both sample types. Similar thermal behavior between the components is a prerequisite for reliable Py-GC/MS analysis. Therefore, this method cannot be recommended for the comparison of carbohydrate compositions between different wood raw materials. However, it is applicable to pulp samples and may find application in research for profiling carbohydrate compositional changes with processing methods: and conditions.

    更新日期:2017-12-14
  • Microstructure and phase evolution in pyrolysed short fibre reinforced polymethylsilsesquioxane-phenolic interpenetrating networks
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-07
    Ancy Smitha Alex, S Bhuvaneswari, C Sarath Chandran, T Jayalatha, V Sekkar, C Gouri

    Simultaneous interpenetrating networks (IPNs) comprising of polymethylsilsesquioxane (PMSQ) and phenolic resole (PF) systems at various PMSQ to PF ratios (0–75% w/w PF) which formed the matrix resin for 60% w/w short silica fibre reinforced composites (SR-PMSQ-PF) are subjected to a controlled heating regime in argon atmosphere at 1500 °C to investigate the microstructure and phase evolution based on IPN composition. This study aims at giving an insight into thermal, mechanical and chemical stability of silicone-phenolic IPN composites, particularly for high temperature thermal protection applications as in aerospace. The morphology and microstructure of the pyrolysed composites are well characterized using Raman and FTIR spectroscopy, XRD and SEM-EDS and based on this a mechanism for microstructure evolution is proposed. It is inferred that the pyrolysis of SR-PMSQ-PF composites results exclusively in the formation of cristobalite silica. In addition to that, the formation of SiC is also facilitated particularly in nano dimension with increase in phenolic content, by carbothermal reduction of silica derived from PMSQ and silica fibre predominantly through solid-vapour phase reaction along the (111) crystalline plane. The systematic evaluation of microstructure and morphology of pyrolysed SR-PMSQ-PF IPN composites is useful to define specific thermal protection applications for these composites.

    更新日期:2017-12-14
  • Lanthanum, cerium, and boron incorporated ZSM-12 zeolites for catalytic cracking of n-hexane
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2017-11-07
    Mohammed A. Sanhoob, Oki Muraza, Masato Yoshioka, Muhammad Qamaruddin, Toshiyuki Yokoi

    Zeolites have a vital role in the conversion of naphtha to more valuable products, especially when the price of crude oil is falling down. Medium-pore zeolites such as MTW zeolite, for instance, require further modification to produce more valuable products with higher selectivity and conversion. ZSM-12 (MTW) zeolite was synthesized and modified using an impregnation method by adding extra-framework elements, namely, cerium, boron, and lanthanum with different loadings to visualize the role of these extra-framework elements on the catalytic cracking. It was observed that impregnation has a negligible effect on the zeolitic phase of MTW zeolites as confirmed by XRD patterns. Weak and strong acid sites were affected by the presence of extra-framework elements. However, impregnation of ZSM-12 with extra-framework elements led to the decrease in Brønsted and increase in Lewis acid sites as observed from pyridine FTIR. The catalytic performance of impregnated ZSM-12 zeolite was applied in n-hexane cracking at 650 °C under atmospheric pressure. Despite the decrease in the catalytic conversion in the presence of the extra-framework, impregnation slightly enhanced the selectivity towards light olefins and depress the selectivity of the paraffin. The highest selectivity to olefins was observed over B-ZSM-12 zeolite with 2 wt.% of boron with an average selectivity of 69% and average conversion of 64% after 240 min.

    更新日期:2017-12-14
  • Thermal pretreatment of a high lignin SSF digester residue to increase its softening point
    J. Anal. Appl. Pyrol. (IF 3.471) Pub Date : 2016-03-24
    Daniel Howe, Manuel Garcia-Perez, Danny Taasevigen, James Rainbolt, Karl Albrecht, Hui Li, Liqing Wei, Armando McDonald, Michael Wolcott

    Residues high in lignin and ash generated from the simultaneous saccharification and fermentation of corn stover were thermally pretreated in an inert (N2) atmosphere to study the effect of time and temperature on their softening points. These residues are difficult to feed into gasifiers due to premature thermal degradation and formation of reactive liquids in the feed lines, leading to plugging. The untreated and treated residues were characterized by proximate and ultimate analysis, and then analyzed via TGA, DSC, 13C NMR, Py-GC–MS, CHNO/S, and TMA. Interpretation of the compositional analysis indicates that the weight loss observed during pretreatment is mainly due to the thermal decomposition and volatilization of the hemicelluloses and amorphous cellulose fractions. Fixed carbon increases in the pretreated material, mostly due to a concentration effect rather than the formation of new extra poly-aromatic material. The optimal processing time and temperature to minimize the production of carbonyl groups in the pretreated samples was 300 °C at a time of 30 min. Results showed that the softening point of the material could be increased from 187 °C to 250 °C, and that under the experimental conditions studied, pretreatment temperature plays a more important role than time. The increase in softening point was mainly due to the formation of covalent bonds in the lignin structures and the removal of low molecular weight volatile intermediates.

    更新日期:2017-12-14
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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