Changes in char properties after catalytic reforming volatiles from pyrolysis of brown coal

CHEN Zong-ding; WANG Yong-gang; XU De-ping; XU Xiu-qiang

Volume 45 Issue 8

Aug. 2017

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CHEN Zong-ding, WANG Yong-gang, XU De-ping, XU Xiu-qiang. Changes in char properties after catalytic reforming volatiles from pyrolysis of brown coal[J]. Journal of Fuel Chemistry and Technology, 2017, 45(8): 908-915.

Citation:

CHEN Zong-ding, WANG Yong-gang, XU De-ping, XU Xiu-qiang. Changes in char properties after catalytic reforming volatiles from pyrolysis of brown coal[J]. Journal of Fuel Chemistry and Technology, 2017, 45(8): 908-915.

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Changes in char properties after catalytic reforming volatiles from pyrolysis of brown coal

1.
National Research Centre for Geoanalysis, Beijing 100037, China
2.
School of Chemical and Environmental Engineering, China University of Mining and Technology (Beijing), Beijing 100083, China

Funds:

The project was supported by the 12th Five-Year Plan of National Science and Technology Support 2012BAA04B02

Received Date: 2017-02-13
Rev Recd Date: 2017-05-02

Available Online: 2021-01-23

Publish Date: 2017-08-10

Abstract

Abstract

To decrease tar yield and thus improving gasification efficiency, tar from pyrolysis of Shengli brown coal was catalytically reformed in situ in a two-stage quartz reactor using char (as catalyst) prepared from the pyrolysis of same coal. The properties of char catalysts before and after reactions were analyzed and compared. The results show that the mass of char generally decreases after the reforming reactions, which means that char is a kind of consumptive catalyst. The maximum reduction in specific surface area after reactions is from 422 to 231.8 m²/g. Results from Raman spectroscopy show that the O-containing functional groups, as well as the ratio of small aromatic rings (3-5 aromatic rings) to big aromatic rings (more than 5 aromatic rings) in char, decrease after the reactions. Besides, it appears that during the interaction between char and volatile, char from fast-heating pyrolysis mainly cracks the volatiles into small-molecule gases, while char from slow-heating pyrolysis removes the volatiles by coking on its surface.
- brown coal,
- pyrolysis,
- char,
- volatile,
- catalytic reforming

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References(18)

References

[1]	WANG L, WU C, ZHAO Z. Effect of char on catalytic cracking of tar from biomass gasification with toluene as a model compound[J]. Acta Energi Sin, 2006, 27(5): 514-518. http://en.cnki.com.cn/Article_en/CJFDTOTAL-TYLX200605018.htm
[2]	WANG F J, ZHANG S, CHEN Z D, LIU C, WANG Y G. Tar reforming using char as catalyst during pyrolysis and gasification of Shengli brown coal[J]. J Anal Appl Pyrolysis, 2014, 105: 269-275. doi: 10.1016/j.jaap.2013.11.013
[3]	ABU E Z, BRAMER E A, BREM G. Experimental comparison of biomass chars with other catalysts for tar reduction[J]. Fuel, 2008, 87: 2243-2252. doi: 10.1016/j.fuel.2008.01.004
[4]	BRANDT P, LARSEN E, HENRIKSEN U. High tar reduction in a two-stage gasifier[J]. Energy Fuels, 2000, 14: 816-824. doi: 10.1021/ef990182m
[5]	ASADULLAH M, ZHANG S, MIN Z H, YIMSIRI P, LI C Z. Effects of biomass char structure on its gasification reactivity[J]. Bioresour Technol, 2010, 101: 7935-7943. doi: 10.1016/j.biortech.2010.05.048
[6]	尤占平. 生物质炭催化重整热解焦油技术研究[D]. 天津: 天津大学, 2010. http://cdmd.cnki.com.cn/Article/CDMD-10056-1011266604.htm YOU Zhan-ping. Research on catalytic reforming of tar from pyrolysis using biomass char as catalyst[D]. Tianjin: Tianjin University, 2010. http://cdmd.cnki.com.cn/Article/CDMD-10056-1011266604.htm
[7]	SONG Y, WANG Y, HU X, XIANG J, HU S, MOURANT D, LI T T, WU L P, LI C Z. Effect of volatile-char interaction on in situ destruction of nascent tar during the pyrolysis and gasification of biomass. Part 1. Roles of nascent char[J]. Fuel, 2014, 122: 60-66. doi: 10.1016/j.fuel.2014.01.002
[8]	陈宗定, 张书, 王芳杰, 贾晓路, 许德平, 王永刚.活化前后半焦原位催化重整褐煤热解焦油研究[J].煤炭科学技术, 2014, 11: 105-110. http://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201411028.htm CHEN Zong-ding, ZHANG Shu, WANG Fang-jie, JIA Xiao-lu, XU De-ping, WANG Yong-gang. Study on in-situ catalytic reforming of coal tar from pyrolysis of brown coal by activated and inactivated char[J]. Coal Sci Technol, 2014, 11: 105-110. http://www.cnki.com.cn/Article/CJFDTOTAL-MTKJ201411028.htm
[9]	ZHANG S, MIN Z H, TAY H L, ASADULLAH M, LI C Z. Effects of volatile-char interactions on the evolution of char structure during the gasification of Victorian brown coal in steam[J]. Fuel, 2011, 90: 1529-1535. doi: 10.1016/j.fuel.2010.11.010
[10]	许修强, 王永刚, 陈宗定, 白磊, 张锟俊, 杨萨莎, 张书.胜利褐煤半焦冷却处理对其微观结构及反应性能的影响[J].燃料化学学报, 2015, 43(1): 1-8. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18547.shtml XU Xiu-qiang, WANG Yong-gang, CHEN Zong-ding, BAI Lei, ZHANG Kun-jun, YANG Sa-sha, ZHANG Shu. Influence of cooling treatments on char microstructure and reactivity of Shengli brown coal[J]. J Fuel Chem Technol, 2015, 43(1): 1-8. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18547.shtml
[11]	许修强, 王永刚, 张书, 陈宗定, 陈绪军, 贺欣.褐煤原位气化半焦的反应性及微观结构的演化行为[J].燃料化学学报, 2015, 03: 273-280. doi: 10.3969/j.issn.0253-2409.2015.03.004 XU Xiu-qiang, WANG Yong-gang, ZHANG Shu, CHEN Zong-ding, CHEN Xu-jun, HE Xin. Evolution behavior of reactivity and micro-structure of lignite char during in-situ gasification with steam[J]. J Fuel Chem Technol, 2015, 03: 273-280. doi: 10.3969/j.issn.0253-2409.2015.03.004
[12]	许修强, 王永刚, 陈国鹏, 陈宗定, 秦中宇, 戴谨泽, 张书, 许德平.水蒸气对褐煤原位气化半焦反应性能及微观结构的影响[J].燃料化学学报, 2015, 43(5): 546-553. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18622.shtml XU Xiu-qiang, WANG Yong-gang, CHEN Guo-peng, CHEN Zong-ding, QIN Zhong-yu, DAI Jin-ze, ZHANG Shu, XU De-ping. Effects of steam on the reactivity and microstructure of char from in-situ gasification of brown coal[J]. J Fuel Chem Technol, 2015, 43(5): 546-553. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18622.shtml
[13]	MIN Z H, ZHANG S, YIMSIRI P, WAGN Y, ASADULLAH M, LI C Z. Catalytic reforming of tar during gasification. Part Ⅳ. Changes in the structure of char in the char-supported iron catalyst during reforming[J]. Fuel, 2013, 106: 858-863. doi: 10.1016/j.fuel.2012.11.063
[14]	LIU S Y, WANG Y, WU R C, ZENG X, GAO S Q, XU G W. Fundamentals of catalytic tar removal over in situ and ex situ chars in two-stage gasification of coal [J]. Energy Fuels, 2014: 58-66. doi: 10.1021/ef4021153
[15]	刘殊远, 汪印, 武荣成, 曾玺, 许光文.热态半焦和冷态半焦催化裂解煤焦油研究[J].燃料化学学报, 2013, 41(9): 1041-1049. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18249.shtml LIU Shu-yuan, WANG Yin, WU Rong-cheng, ZENG Xi, XU Guang-wen. Research on coal tar catalytic cracking over hot in-situ chars[J]. J Fuel Chem Technol, 2013, 41(9): 1041-1049. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18249.shtml
[16]	MIN Z H, YIMSIR P, ASADULLAH M, ZHANG S, LI C Z. Catalytic reforming of tar during gasification:char as a catalyst or as a catalyst support for tar reforming[J]. Fuel, 2011, 90(5): 2545-2552. http://www.sciencedirect.com/science/article/pii/S0016236111001554
[17]	MIN Z H, ASADULLAH M, PIYACHAT Y, ZHANG S, WU H, LI C Z. Catalytic reforming of tar during gasification. Part Ⅰ. Steam reforming of biomass tar using ilmenite as a catalyst[J]. Fuel, 2011, 90: 1847-1854. doi: 10.1016/j.fuel.2010.12.039
[18]	KEOWN D M, HAYASHI J I, LI C Z. Drastic changes in biomass char structure and reactivity upon contact with steam[J]. Fuel, 2008, 87: 1127-1132. doi: 10.1016/j.fuel.2007.05.057