logo

SCIENCE CHINA Technological Sciences, Volume 62 , Issue 11 : 2029-2037(2019) https://doi.org/10.1007/s11431-018-9492-5

Metal chloride influence on syngas component during coal pyrolysis in fixed-bed and entrained flow drop-tube furnace

More info
  • ReceivedNov 5, 2018
  • AcceptedMar 12, 2019
  • PublishedJun 26, 2019

Abstract

Pyrolysis was carried out in an entrained flow drop-tube furnace (DTF) and tube furnace (TF) using Pingzhuang lignite coal with various catalyst concentrations (2 wt%, 4 wt%, and 6 wt%) of KCl and CaCl2 for the syngas component at 800°C–1200°C. Five catalysts (KCl, CaCl2, NiCl2, MnCl2, and ZnCl2) at 6 wt% were chosen for DTF at 800°C–1200°C. An online gas chromatograph analyzer and the Fourier transform infrared spectra were used for the analysis of the syngas and char structure. Results showed that the overall CO2 and CH4 content in DTF was lower than that in TF, mainly due to the CH4 carbon reaction at high temperature. Moreover, the CO% in DTF was higher than in the TF experiment, as char reacts with carbon dioxide to form carbon monoxide. In DTF experiment, the maximum and minimum CO2 content was 15.20% with 6 wt% Mn at 800°C and 0.33% with 6 wt% K at 1100°C, respectively. The maximum CO% was found in raw coal. Concentrations of Mn2+, Zn2+, and K+ can significantly increase H2%, whereas Ca2+ and Ni2+ have a minor effect on H2%; however, the overall presence of catalyst has a positive impact on the H2 content.


Funded by

the Innovative Research Groups of the National Natural Science Foundation of China(Grant,No.,51621005)


Acknowledgment

This work was supported by the Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 51621005).


References

[1] British Petroleum (BP). Statistical review of world energy. https://www.bp.com/en/global/corporate/energy-economics/statistical-review-of-world-energy/coal.html#coal-reserves, 2017. Google Scholar

[2] Zellagui S, Schönnenbeck C, Zouaoui-Mahzoul N, et al. Pyrolysis of coal and woody biomass under N2 and CO2 atmospheres using a drop tube furnace: Experimental study and kinetic modeling. Fuel Process Technol, 2016, 148: 99-109 CrossRef Google Scholar

[3] Guo R, Yang J, Liu Z. Behavior of trace elements during pyrolysis of coal in a simulated drop-tube reactor. Fuel, 2004, 83: 639-643 CrossRef Google Scholar

[4] Gonzalez V, Rußig S, Schurz M, et al. Experimental investigations on lignite char gasification kinetics using a pressurized drop tube reactor. Fuel, 2018, 224: 348-356 CrossRef Google Scholar

[5] Valdés C F, Chejne F. Effect of reaction atmosphere on the products of slow pyrolysis of coals. J Anal Appl Pyrolysis, 2017, 126: 105-117 CrossRef Google Scholar

[6] Liu L, Kumar S, Wang Z, et al. Catalytic effect of metal chlorides on coal pyrolysis and gasification part I. Combined TG-FTIR study for coal pyrolysis. Thermochim Acta, 2017, 655: 331-336 CrossRef Google Scholar

[7] Xu W C, Tomita A. The effects of temperature and residence time on the secondary reactions of volatiles from coal pyrolysis. Fuel Process Technol, 1989, 21: 25-37 CrossRef Google Scholar

[8] Wang H, Chen Z, Zhang X, et al. Thermal decomposition mechanisms of coal and coal chars under CO2 atmosphere using a distributed activation energy model. Thermochim Acta, 2018, 662: 41-46 CrossRef Google Scholar

[9] Griffin T P, Howard J B, Peters W A. Pressure and temperature effects in bituminous coal pyrolysis: Experimental observations and a transient lumped-parameter model. Fuel, 1994, 73: 591-601 CrossRef Google Scholar

[10] Cetin E, Gupta R, Moghtaderi B. Effect of pyrolysis pressure and heating rate on radiata pine char structure and apparent gasification reactivity. Fuel, 2005, 84: 1328-1334 CrossRef Google Scholar

[11] Calkins W H. Investigation of organic sulfur-containing structures in coal by flash pyrolysis experiments. Energy Fuels, 1987, 1: 59-64 CrossRef Google Scholar

[12] Zhang K, Li Y, He Y, et al. Volatile gas release characteristics of three typical Chinese coals under various pyrolysis conditions. J Energy Institute, 2018, 91: 1045-1056 CrossRef Google Scholar

[13] Reichel D, Siegl S, Neubert C, et al. Determination of pyrolysis behavior of brown coal in a pressurized drop tube reactor. Fuel, 2015, 158: 983-998 CrossRef Google Scholar

[14] Li Q, Wang Z, He Y, et al. Pyrolysis characteristics and evolution of char structure during pulverized coal pyrolysis in drop tube furnace: Influence of temperature. Energy Fuels, 2017, 31: 4799-4807 CrossRef Google Scholar

[15] Binner E, Facun J, Chen L, et al. Effect of coal drying on the behavior of inorganic species during victorian brown coal pyrolysis and combustion. Energy Fuels, 2011, 25: 2764-2771 CrossRef Google Scholar

[16] Ohtsuka Y, Asami K. Highly active catalysts from inexpensive raw materials for coal gasification. Catal Today, 1997, 39: 111-125 CrossRef Google Scholar

[17] Clemens A H, Damiano L F, Matheson T W. The effect of calcium on the rate and products of steam gasification of char from low rank coal. Fuel, 1998, 77: 1017-1020 CrossRef Google Scholar

[18] Wang J, Yao Y, Cao J, et al. Enhanced catalysis of K2CO3 for steam gasification of coal char by using Ca(OH)2 in char preparation. Fuel, 2010, 89: 310-317 CrossRef Google Scholar

[19] Ding L, Dai Z, Wei J, et al. Catalytic effects of alkali carbonates on coal char gasification. J Energy Institute, 2017, 90: 588-601 CrossRef Google Scholar

[20] Tang J, Wang J. Catalytic steam gasification of coal char with alkali carbonates: A study on their synergic effects with calcium hydroxide. Fuel Process Technol, 2016, 142: 34-41 CrossRef Google Scholar

[21] Ding L, Zhou Z, Guo Q, et al. Catalytic effects of Na2CO3 additive on coal pyrolysis and gasification. Fuel, 2015, 142: 134-144 CrossRef Google Scholar

[22] Zhang F, Fan M, Huang X, et al. Catalytic gasification of a powder river basin coal with CO2 and H2O mixtures. Fuel Process Technol, 2017, 161: 145-154 CrossRef Google Scholar

[23] Zhang J, Zhang R, Bi J. Effect of catalyst on coal char structure and its role in catalytic coal gasification. Catal Commun, 2016, 79: 1-5 CrossRef Google Scholar

[24] Zhang L, Kudo S, Tsubouchi N, et al. Catalytic effects of Na and Ca from inexpensive materials on in-situ steam gasification of char from rapid pyrolysis of low rank coal in a drop-tube reactor. Fuel Process Technol, 2013, 113: 1-7 CrossRef Google Scholar

[25] Li Q, Wang Z, Lin Z, et al. Effects of hydrothermal modification on sulfur release of low-quality coals during thermal transformation process. J Energy Resour Technol, 2018, 140: 072201 CrossRef Google Scholar

[26] Sun Z, Wu J, Haghighi M, et al. Methane cracking over a bituminous coal char. Energy Fuels, 2007, 21: 1601-1605 CrossRef Google Scholar

[27] Zou X, Yao J, Yang X, et al. Catalytic effects of metal chlorides on the pyrolysis of lignite. Energy Fuels, 2007, 21: 619-624 CrossRef Google Scholar

[28] Murakami K, Shirato H, Ozaki J, et al. Effects of metal ions on the thermal decomposition of brown coal. Fuel Process Technol, 1996, 46: 183-194 CrossRef Google Scholar

[29] Song H, Liu G, Zhang J, et al. Pyrolysis characteristics and kinetics of low rank coals by TG-FTIR method. Fuel Process Technol, 2017, 156: 454-460 CrossRef Google Scholar

[30] Liu L, Yuan Y, Kumar S, et al. Catalytic effect of metal chlorides on coal pyrolysis and gasification part Ⅱ. Effects of acid washing on coal characteristics. Thermochim Acta, 2018, 666: 41-50 CrossRef Google Scholar

[31] Niu Z, Liu G, Yin H, et al. Investigation of mechanism and kinetics of non-isothermal low temperature pyrolysis of perhydrous bituminous coal by in-situ FTIR. Fuel, 2016, 172: 1-10 CrossRef Google Scholar

Copyright 2020  CHINA SCIENCE PUBLISHING & MEDIA LTD.  中国科技出版传媒股份有限公司  版权所有

京ICP备14028887号-23       京公网安备11010102003388号