scholarly journals Investigation on Thermal and Kinetic Characteristics During Co-Pyrolysis of Coal and Lignocellulosic Agricultural Residue

2014 ◽  
Author(s):  
Zhiqiang Wu ◽  
Shuzhong Wang ◽  
Jun Zhao ◽  
Lin Chen ◽  
Haiyu Meng
Keyword(s):  
Activation Energy ◽  
Synergistic Effect ◽  
Wheat Straw ◽  
Lignocellulosic Biomass ◽  
Bituminous Coal ◽  
Mass Ratio ◽  
Heating Rates ◽  
Agricultural Residue ◽  
Remarkable Effect ◽  
Mixing Ratios

Co-utilization of coal and lignocellulosic biomass has the potential to reduce greenhouse gases emission from energy production. As a fundamental step of typically thermochemical co-utilization (e.g., co-combustion, co-gasification), co-pyrolysis of coal and lignocellulosic biomass has remarkable effect on the conversation of the further step. Thermal behavior and kinetic analysis are prerequisite for predicting co-pyrolysis performance and modeling co-gasification and co-combustion processes. In this paper, co-pyrolysis behavior of a Chinese bituminous coal blended with lignocellulosic agricultural residue (wheat straw collected from north of China) and model compound (cellulose) were explored via thermogravimetric analyzer. Bituminous coal and lignocellulosic agricultural residue were heated from ambient temperature to 900 °C under different heating rates (10, 20, 40 °C·min−1) with various mass mixing ratios (coal/lignocellulosic agricultural residue ratios of 100, 75/25, 50/50, 25/75 and 0). Activation energy were calculate via iso-conversional method (eg. Kissinger-Akahira-Sunose, Flynn-Wall-Ozawa and Starink methods). The results indicated that pyrolysis rate of coal was accelerated by wheat straw under all mixing conditions. Cellulose promoted the pyrolysis rate of coal under equal or lesser than 50% mass ratio. Some signs about positive or passive synergistic effect were found in char yield. Char yields were lower than that calculated from individual samples for bituminous coal and wheat straw. With the increasing of cellulose mass ratio, the positive synergies on char yields were reduced, resulting in passive synergistic effect especially under higher coal/cellulose mass ratio (25/75). Nonlinearity performance was observed from the distribution of activation energy.

Pyrolytic Behavior and Kinetic Analysis of Wheat Straw and Lignocellulosic Biomass Model Compound

2013 ◽  
Vol 860-863 ◽  
pp. 550-554 ◽  
Author(s):  
Zhi Qiang Wu ◽  
Shu Zhong Wang ◽  
Jun Zhao ◽  
Lin Chen ◽  
Hai Yu Meng
Keyword(s):  
Activation Energy ◽  
Kinetic Analysis ◽  
Wheat Straw ◽  
Lignocellulosic Biomass ◽  
Nitrogen Atmosphere ◽  
Thermochemical Conversion ◽  
Heating Rates ◽  
Decomposition Rates ◽  
Model Compounds ◽  
Pyrolysis Of Biomass

From a carbon cycle perspective, the thermochemical conversion of lignocellulosic biomass is inherently carbon neutral. Pyrolysis of biomass for energy supplying, such as bio-oil and bio-char, has been attracted much attention worldwide. Successful understanding the fundamental issues about the pyrolysis, including pyrolytic behavior and kinetic analysis of lignocellulosic biomass model compounds and real biomass, is essential for the further understanding and optimizing the pyrolysis process. In this paper, pyrolytic behavior of a typical lignocellulosic agricultural residue (wheat straw) and model compounds (cellulose) were measured through thermogravimetric analysis with various heating rates (10, 20, 40 °C·min-1) under nitrogen atmosphere. The results indicated that the interval of the weight loss for both wheat straw and cellulose moved upwards with the increment of heating rates. The maximum decomposition rates of cellulose were higher than those of wheat straw, and the temperature of maximum decomposition rates increased with the heating rates. Values of activation energy were solved through iso-conversional method. And the average values of activation energy for wheat straw and cellulose were 146.89 kJ·mol-1 and 134.56 kJ·mol-1 calculated from Flynn-Wall-Ozawa method, 144.05 kJ·mol-1 and 130.91 kJ·mol-1 calculated from Kissinger-Akahira-Sunose method, respectively.

A Kinetic Study of Co-Pyrolysis of Coal and Spent Mushroom Compost (SMC)

2013 ◽  
Vol 781-784 ◽  
pp. 2406-2410 ◽  
Author(s):  
Zhi Qiang Wu ◽  
Shu Zhong Wang ◽  
Qi Xing Guo ◽  
Jun Zhao ◽  
Lin Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Chemical Compounds ◽  
Initial Step ◽  
Mass Ratio ◽  
Intensive Study ◽  
Heating Rates ◽  
Mushroom Compost ◽  
Spent Mushroom Compost ◽  
Pyrolysis Characteristics ◽  
Fwo Method

Co-utilization of coal and biomass has been shown as an effective way to reduce the carbon footprint. Pyrolysis technology not only transform carbonaceous materials such as coal and biomass into various chemical compounds and fuels, but also as the initial step of the thermochemical conversation. For the sake of a better understanding of the co-thermal conversation, it is very necessary to get a intensive study on the co-pyrolysis of coal and biomass. In this paper the co-pyrolysis characteristics of coal and spent mushroom compost (SMC) were investigated through an thermogravimetry analyzer from ambient temperature to 950 °C at different heating rates (10, 20 and 40 °C/min) under nitrogen condition. Kinetic parameters were determined by the by the Flynn-Wall-Ozawa (FWO) method. It was found that the activation energy decreased with the increasing of the biomass mass ratio, but with the biomass ratio reached 0.75 the activation energy increased again. This may be involved with the negative synergies between the biomass and coal. The results could provide useful information for the further study on the co-pyrolysis of coal and MSC.

Co-Gasification Characteristic and Kinetic Analysis of Spent Mushroom Compost and Bituminous Coal

2014 ◽  
Vol 577 ◽  
pp. 71-76 ◽  
Author(s):  
Zhi Qiang Wu ◽  
Shu Zhong Wang ◽  
Jun Zhao ◽  
Lin Chen ◽  
Hai Yu Meng
Keyword(s):  
Activation Energy ◽  
Kinetic Analysis ◽  
Large Scale ◽  
Bituminous Coal ◽  
Western China ◽  
Heating Rates ◽  
Mushroom Compost ◽  
Essential Information ◽  
Spent Mushroom Compost ◽  
Carbon Dioxide Atmosphere

Co-gasification of biomass and coal is increasingly considered as a promising technology for sustainable utilization of coal and large-scale use of biomass. Co-gasification characteristic and kinetic analysis are the basic and essential information for the application of this technology. In this paper, co-gasification behavior of a typical bituminous coal from western China and spent mushroom compost (SMC) was investigated through thermogravimetric analyzer. The temperature interval was from ambient temperature to 1000 ○C with various heating rates (10, 20, 40 ○C•min-1) under carbon dioxide atmosphere. Kinetic parameter was solved through Distribution Activation Energy Model (DAEM). The results indicated that he maximum decomposition rates of the mixture and SMC were higher than that of coal except 25% SMC. Slightly synergistic effect during the co-gasification was found. The average values of the activation energy were 25.07 kJ•mol-1 for bituminous coal, 204.47 kJ•mol-1 for 25% SMC, 123.14 kJ•mol-1 for 50% SMC, 144.05 kJ•mol-1 for 75% SMC and 227.50 kJ•mol-1 for SMC, respectively.

Thermogravimetric Study on the Co-Pyrolysis Characteristics of Bituminous Coal and Wheat Straw

2014 ◽  
Vol 1070-1072 ◽  
pp. 146-151
Author(s):  
Xin Ping Yan ◽  
Ji Song Bai ◽  
Xiong Zhou ◽  
Shun Hong Lin
Keyword(s):  
Activation Energy ◽  
Thermogravimetric Analysis ◽  
Wheat Straw ◽  
Bituminous Coal ◽  
Synergistic Effects ◽  
Order Reaction ◽  
Pyrolysis Process ◽  
First Order ◽  
Pyrolysis Characteristics ◽  
Apparent Kinetic Parameters

In this work, the pyrolysis behavior of bituminous coal (BC) wheat straw (WS) and the blends were investigated by thermogravimetric analysis. It was found that the main thermal degradation stage of BC and WS lies in different temperature range and there is nearly no overlapping. Interaction was observed during the co-pyrolysis process of BC and WS. At high temperatures, the volatile releasing is slightly inhibited by WS addition. Coats-Redfern method was used to analyze the apparent kinetic parameters. The results indicated that both the two reaction stages during pyrolysis process are well correlated by first-order reaction. The variation trend of activation energy value further confirm the synergistic effects between BC and WS. The experimental results may provide useful data for co-thermochemical utilization of biomass with coal.

scholarly journals Co-Combustion Studies of Low-Rank Coal and Refuse-Derived Fuel: Performance and Reaction Kinetics

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3796
Author(s):  
Mudassar Azam ◽  
Asma Ashraf ◽  
Saman Setoodeh Setoodeh Jahromy ◽  
Sajjad Miran ◽  
Nadeem Raza ◽  
...  
Keyword(s):  
Activation Energy ◽  
Waste Management ◽  
Energy Demand ◽  
Power Plants ◽  
Combustion Process ◽  
Isoconversional Methods ◽  
Low Rank ◽  
Heating Rates ◽  
Average Activation Energy ◽  
Refuse Derived Fuel

In connection to present energy demand and waste management crisis in Pakistan, refuse-derived fuel (RDF) is gaining importance as a potential co-fuel for existing coal fired power plants. This research focuses on the co-combustion of low-quality local coal with RDF as a mean to reduce environmental issues in terms of waste management strategy. The combustion characteristics and kinetics of coal, RDF, and their blends were experimentally investigated in a micro-thermal gravimetric analyzer at four heating rates of 10, 20, 30, and 40 °C/min to ramp the temperature from 25 to 1000 °C. The mass percentages of RDF in the coal blends were 10%, 20%, 30%, and 40%, respectively. The results show that as the RDF in blends increases, the reactivity of the blends increases, resulting in lower ignition temperatures and a shift in peak and burnout temperatures to a lower temperature zone. This indicates that there was certain interaction during the combustion process of coal and RDF. The activation energies of the samples were calculated using kinetic analysis based on Kissinger–Akahira–Sunnose (KAS) and Flynn–Wall–Ozawa (FWO), isoconversional methods. Both of the methods have produced closer results with average activation energy between 95–121 kJ/mol. With a 30% refuse-derived fuel proportion, the average activation energy of blends hit a minimum value of 95 kJ/mol by KAS method and 103 kJ/mol by FWO method.

Thermo-catalytic decomposition of polystyrene waste: Comparative analysis using different kinetic models

2019 ◽  
Vol 38 (2) ◽  
pp. 202-212 ◽  
Author(s):  
Ghulam Ali ◽  
Jan Nisar ◽  
Munawar Iqbal ◽  
Afzal Shah ◽  
Mazhar Abbas ◽  
...  
Keyword(s):  
Activation Energy ◽  
Copper Oxide ◽  
Solid Waste ◽  
Thermodynamic Parameters ◽  
Model Fitting ◽  
Catalytic Decomposition ◽  
Decomposition Reaction ◽  
Inert Atmosphere ◽  
Heating Rates ◽  
Model Free

Due to a huge increase in polymer production, a tremendous increase in municipal solid waste is observed. Every year the existing landfills for disposal of waste polymers decrease and the effective recycling techniques for waste polymers are getting more and more important. In this work pyrolysis of waste polystyrene was performed in the presence of a laboratory synthesized copper oxide. The samples were pyrolyzed at different heating rates that is, 5°Cmin−1, 10°Cmin−1, 15°Cmin−1 and 20°Cmin−1 in a thermogravimetric analyzer in inert atmosphere using nitrogen. Thermogravimetric data were interpreted using various model fitting (Coats–Redfern) and model free methods (Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman). Thermodynamic parameters for the reaction were also determined. The activation energy calculated applying Coats–Redfern, Ozawa–Flynn–Wall, Kissinger–Akahira–Sunose and Friedman models were found in the ranges 105–148.48 kJmol−1, 99.41–140.52 kJmol−1, 103.67–149.15 kJmol−1 and 99.93–141.25 kJmol−1, respectively. The lowest activation energy for polystyrene degradation in the presence of copper oxide indicates the suitability of catalyst for the decomposition reaction to take place at lower temperature. Moreover, the obtained kinetics and thermodynamic parameters would be very helpful in determining the reaction mechanism of the solid waste in a real system.

Magnetic Properties, Nanostructure, and Ordering Kinetics of Nb Additive FePtCu Films

2010 ◽  
Vol 638-642 ◽  
pp. 1743-1748
Author(s):  
G.J. Chen ◽  
Y.H. Shih ◽  
Jason S.C. Jang ◽  
S.R. Jian ◽  
P.H. Tsai ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Magnetic Properties ◽  
Heating Rates ◽  
Fept Alloy ◽  
Ordering Kinetics ◽  
Nb Content ◽  
Kinetics Of ◽  
Nb Addition ◽  
Microstructure And Magnetic Properties

In this study,the (FePt)94-xCu6Nbx (x=0, 2.87, 4.52, 5.67) alloy films were prepared by co-sputtering. The effects of Nb addition content and heat treatment on the microstructure and magnetic properties of the polycrystalline FePtCu films are reported. Our previous experiments showed that the ordering temperature of the (FePt)94Cu6 films reduced to 320 °C, which is much lower than that of the FePt alloy. However, the grain growth after heat treatment limited the practical application in recording media. By adding the Nb content in the (FePt)94Cu6 film, the grain sizes of the films can be adjusted from 50 to 18nm, even for the films annealed at temperature as high as 600°C. DSC traces of as-deposited disorder films at different heating rates, to evaluate the crystallization of the order phase, revealed that the addition of Nb enhanced the activation energy of ordering from 87 kJ/mol to 288 kJ/mol for the (FePt)94-xCu6Nbx (x=0 and 2.87, respectively) films. The reduction of the grain size and the corresponding increase in the activation energy of the Fe-Pt-Cu-Nb films might result from the precipitation of the Nb atoms around the ordering FePt phase. The (FePt)94-xCu6Nbx (x=2.87) film showed a coercive force of 13.4 kOe and the magnetization of 687 emu/cc.

Thermogravimetric devolatisation behavior of agricultural residue for generation of syngas

2021 ◽  
pp. 1-17
Author(s):  
Praveen Kumar ◽  
P.M.V. Subbarao ◽  
L.D. Kala ◽  
V.K. Vijay
Keyword(s):  
Activation Energy ◽  
Pearl Millet ◽  
Proximate Analysis ◽  
Thermochemical Conversion ◽  
Degradation Behavior ◽  
Ozawa Method ◽  
Thermogravimetric Method ◽  
Agricultural Residue ◽  
Tg Analysis ◽  
Tg And Dtg

Abstract The thermal degradation characteristics of eucalyptus, pearl millet cob, and corncob were investigated using non-isothermal thermogravimetric method. This investigation was performed with the objective of carrying out thermochemical conversion for obtaining syngas. TG and DTG analysis were carried out to understand thermal devolatisation behavior and estimation of various thermophysical properties of the biomasses. The degradation behavior was analysed in the light of lignocellulosic composition that was found to have definitive influence on degradation outcomes. TG analysis has been utilized to obtain proximate analysis of biomass. Activation energy using Flynn-Wall-Ozawa method have been estimated and found to be 201, 150 and 68 kJ mol−1 for eucalyptus, pearl millet cob, and corncob respectively. The TG analysis and activation energy together indicated that corncob is easiest for thermochemical conversion amongst the three biomasses. The TG curve also confirms the same.

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