Study on the Pyrolysis Characteristics and Mechanism of KCl-Pretreated Sunflower Stalk

2013 ◽  
Vol 448-453 ◽  
pp. 1665-1674
Author(s):  
Dong Yu Chen ◽  
Qing Yu Liu ◽  
Yan Qing Hu

To study the influence of KCl pretreating on the pyrolysis kinetics of sunflower stalk, the pyrolysis of sunflower stalk pretreated by different concentration KCl solutions were performed by nonisothermal thermogravimetric analysis (TGA) at five different heating rates. The Ozawa and Kissinger methods were employed to calculate the activation energy and the Šatava method was used to obtain the kinetic mechanism model. The results showed that the pyrolysis process of the sunflower stalk pretreated by 3% and 10% KCl solution can be separated into four stages (water loss, depolymerization and vitrification, thermal decomposition, and carbonization). With the heating rate increasing, the main pyrolysis zone of the TG (thermogravimetric) and DTG curves move to the higher temperature direction, and the maximum pyrolysis rate and its corresponding temperature increase too. Adding a small amount of metal salts is conducive to the formation of volatile, and a certain amount of metal salts can improve the charcoal yield. More KCl additive makes the lower activation energy value, and the obtained activation energy value increases with the heating rate increasing. By means of the Šatava method, the kinetic mechanism model for the pyrolysis of KCl-pretreated sunflower stalk is Zhuralev-Lesakin-Tempelman equation, which is three-dimensional diffusion.

2015 ◽  
Vol 1092-1093 ◽  
pp. 118-121
Author(s):  
Dong Yu Chen ◽  
Qing Yu Liu

To study the influence of KCl pretreating on the pyrolysis kinetics of soybean stalk, the pyrolysis of soybean stalk pretreated by different concentration KCl solutions were performed by nonisothermal thermogravimetric analysis (TGA) at five different heating rates. The Ozawa method was employed to calculate the activation energy. The results showed that the pyrolysis process of the soybean stalk pretreated by 3% and 10% KCl solution can be separated into four stages (water loss, depolymerization and vitrification, thermal decomposition, and carbonization). With the heating rate increasing, the main pyrolysis zone of the TG (thermogravimetric) and DTG curves move to the higher temperature region, and the maximum pyrolysis rate and its corresponding temperature increase too. A small amount of metal salts addition is conducive to the formation of volatile, and a certain amount of metal salts can improve the charcoal yield. More KCl additive makes the lower activation energy value, and the obtained activation energy value increases with the reaction degree.


2014 ◽  
Vol 953-954 ◽  
pp. 261-266
Author(s):  
Dong Yu Chen ◽  
Yan Qing Hu ◽  
Qing Yu Liu

To study the influences of the acid-washing on the characteristics of soybean stalk pyrolysis , and search the high-efficiency catalyst for biomass pyrolysis, pyrolysis experiments of soybean stalk pretreated by 0.1mol/L HCl acid solution were performed by nonisothermal thermogravimetric analysis (TGA) at five different heating rates. The results showed the pyrolysis process of HCl-washed soybean stalk can be separated into four stages (water loss, depolymeri-zation and vitrification, thermal decomposition, and carbonization). At the same heating rate, the maximum pyrolysis rate of HCl-washed is larger than untreated soybean stalk, but the corresponding temperature is higher. All the DTG (differential thermogravimetric) curveas appear a smaller shoulder peak respectively. With the heating rate increasing, the main pyrolysis zone of the TG (thermogravimetric) and DTG curves move to the high-temperature direction, and the maximum pyrolysis rate and its corresponding temperature increase too. HCl-wahsed makes the weight loss rate of the final temperature increase 5% approximately. The value area of activation energy of the main pyrolysis area is 140.19~174.59 kJ/mol calculated by the method of Ozawa. The Šatava method inferred the most possible mechanism function of HCl-wahsed soybean stalk is Zhuralev-Lesakin-Tempelman equation, which is three-dimensional diffusion.


2014 ◽  
Vol 960-961 ◽  
pp. 442-446
Author(s):  
Lin Chen ◽  
Shu Zhong Wang ◽  
Zhi Qiang Wu ◽  
Hai Yu Meng ◽  
Jun Zhao

Wood-based materials from Municipal Solid Waste have the potential of covering a significant part of the future demand on gasification capacities. However, their pyrolysis kinetics and gasification behavior has not yet been fully investigated. This paper describes the pyrolysis characteristics of typing paper and Chinese parasol from municipal solid waste applying the non-isothermal thermogravimetric analysis, the apparent activation energy and the pre-exponential factor were obtained by kinetics analysis at the heating rate of 10/20/40 oC•min-1.


2014 ◽  
Vol 9 (2) ◽  
pp. 155892501400900
Author(s):  
Tao Wang ◽  
Xianlin Xu ◽  
Yanlin Ren ◽  
Songtao Qin ◽  
Xiaoyang Sui ◽  
...  

The thermal decomposition behavior of fire retardant viscose fiber and viscose fiber were studied by thermogravimetric analysis (TGA) under air atmosphere at heating rates of 10, 20, 30 and 40oC/min. The activation energy and pre-exponential factor were calculated by using the Kissinger method, Flynn-Wall-Ozawa (FWO) method and Satava-Sestak method. The results show that the activation energy for the fire retardant viscose fiber calculated by Kissinger and FWO method was 102.51kJ/mol and 103.73kJ/mol, respectively. The activation energy for viscose fiber calculated by Kissinger and FWO method was 103.58 kJ/mol and 104.83kJ/mol, respectively. The kinetic mechanism function of fire retardant viscose fiber was G(α) = [(1+ α)13-1]2 following a kinetic model of three-dimensional diffusion and the kinetic mechanism function of viscose fiber was G(α) = α3/2 following the power function rule.


2020 ◽  
Vol 39 (2) ◽  
pp. 227
Author(s):  
Adnan Kurt ◽  
Hacer Andan ◽  
Murat Koca

A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.


2012 ◽  
Vol 550-553 ◽  
pp. 2758-2762 ◽  
Author(s):  
Xi Jie Chu ◽  
Yong Gang Wang ◽  
Li Hong Zhao

The pyrolysis tests of Shenhua coal and Shenhua direct liquefaction residue have been carried out using thermogravimetric at the differential heating rate. The kinetic parameters k and E were calculated using DAEM method. Results show DAME model can describe the pyrolysis behavior of Shenhua coal within the range of 20% to 95%, the activation energy of coal pyrolysis ranges from 53.98 to 279.38 kJ/mol, and DAME model can describe the behavior of Shenhua direct liquefaction residue within the range of 10% to 80%, the activation energy of residue pyrolysis is about 170 kJ/mol. The results of which are basically consistent with the experimental data.


2013 ◽  
Vol 781-784 ◽  
pp. 2009-2012 ◽  
Author(s):  
Hai Yu Meng ◽  
Shu Zhong Wang ◽  
Lin Chen ◽  
Jun Zhao ◽  
Zhi Qiang Wu

The pyrolysis characteristics of pine powder and polyvinyl chloride (PVC), respectively representing the biomass and plastics components of municipal solid waste, were studied in a thermogravimetric analyzer, and the influence of heating rate on pyrolysis characteristics was also investigated. The pyrolysis temperature was heated from ambient up to 900 °C at different heating rates including 10, 20 and 40 °Cžmin-1. The pyrolysis of pine powder was composed of two obvious weight loss phases, which were dehydration and the decomposition of cellulose and hemicellulose. The lignin in pine powder decomposed over a broad temperature range until 900°C. The pyrolysis of PVC was complicated, and included the release of hydrogen chloride (HCl), the formation of hydrocarbons. Besides, the additives in PVC decomposed at about 600 °C. The TG and DTG curves of pyrolysis for pine powder and PVC were similar at different heating rates, however, each weight loss phase of pyrolysis was shifted to high temperature with increasing the heating rate.


2013 ◽  
Vol 781-784 ◽  
pp. 2406-2410 ◽  
Author(s):  
Zhi Qiang Wu ◽  
Shu Zhong Wang ◽  
Qi Xing Guo ◽  
Jun Zhao ◽  
Lin Chen ◽  
...  

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.


2019 ◽  
Vol 38 (1) ◽  
pp. 298-309
Author(s):  
Fredy Surahmanto ◽  
Harwin Saptoadi ◽  
Hary Sulistyo ◽  
Tri A Rohmat

The pyrolysis kinetics of oil-palm solid waste was investigated by performing experiments on its individual components, including empty fruit bunch, fibre, shell, as well as the blends by using a simultaneous thermogravimetric analyser at a heating rate of 10°C/min under nitrogen atmosphere and setting up from initial temperature of 30°C to a final temperature of 550°C. The results revealed that the activation energy and frequency factor values of empty fruit bunch, fibre, and shell are 7.58–63.25 kJ/mol and 8.045E-02–4.054E + 04 s−1, 10.45–50.76 kJ/mol and 3.639E-01–5.129E + 03 s−1, 9.46–55.64 kJ/mol and 2.753E-01–9.268E + 03, respectively. Whereas, the corresponding values for empty fruit bunch–fibre, empty fruit bunch–shell, fibre–shell, empty fruit bunch–fibre–shell are 2.97–38.35 kJ/mol and 1.123E-02–1.326E + 02 s−1, 7.95–40.12 kJ/mol and 9.26E-02–2.101E + 02 s−1, 9.14–50.17 kJ/mol and 1.249E-01–2.25E + 03 s−1, 8.35–45.69 kJ/mol and 1.344E + 01–4.23E + 05 s−1, respectively. It was found that the activation energy and frequency factor values of the blends were dominantly due to the role of the components with a synergistic effect occurred during pyrolysis.


2013 ◽  
Vol 848 ◽  
pp. 126-130
Author(s):  
Hua Xiao Yan ◽  
Hui Zhao ◽  
Qi Liu ◽  
Yan Xiang Ai ◽  
Yan Zhang ◽  
...  

The Suaeda salsa L. has been discovered to be a great potential as a new kind of renewable energy. The pyrolytic characteristics and kinetics of S. salsa were investigated at heating rates of 5, 10, 20, 30°C/min under nitrogen atmosphere respectively. The most probable mechanism function was deduced using Popescu method, which is a three-dimensional diffusion function (), and n=-2/3. Activation energy and pre-exponential factors were studied through the FWO, KAS and Popescu methods. The results showed that the activation energy increase as the pyrolysis process and three stages were observed in the TG-DTG curves of S.salsa. The results showed that S.salsa as a pyrolysis feedstock has a great potential and a good prospect in bio-oil production.


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