Pyrolysis of coal with different moisture contents in fixed-bed reactorwith internals

doi:10.11949/j.issn.0438-1157.20141772

CIESC Journal ›› 2015, Vol. 66 ›› Issue (7): 2656-2663.DOI: 10.11949/j.issn.0438-1157.20141772

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Pyrolysis of coal with different moisture contents in fixed-bed reactorwith internals

HU Erfeng^1,2, ZHANG Chun², WU Rongcheng², FU Xiaoheng¹, XU Guangwen²

1 School of Chemical and Environmental Engineering, China University of Mining & Technology, Beijing 100083, China;
2 State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China

Received:2014-11-30 Revised:2015-05-11 Online:2015-07-05 Published:2015-07-05
Supported by:
supported by the National Basic Research Program of China (2011CB201304), the National Natural Science Foundation of China (U1302273), the International Science & Technology Cooperation Program of China (2013DFG60060), the “Strategic Priority Research Program” of CAS on Clean and High Efficiency Utilization of Low-rank Coal (XDA07050400) and the National Natural Science Foundation of China (21306209, 21106156).

内构件固定床反应器中不同水分煤的热解特性

胡二峰^1,2, 张纯², 武荣成², 付晓恒¹, 许光文²

１中国矿业大学北京化学与环境工程学院, 北京 100083;
2 中国科学院过程工程研究所多相复杂系统国家重点实验室, 北京 100190

通讯作者: 许光文
基金资助:
国家重点基础研究发展计划项目(2011CB201304);国家自然科学基金云南联合基金项目(U1302273);国家国际科技合作专项资助项目(2013DFG60060);中国科学院战略性先导科技专项“低阶煤清洁高效利用关键技术与示范”(XDA07050400);国家自然科学基金项目(21306209, 21106156)。

Abstract

Abstract:

The effects of coal moisture on heating rate and product distribution for pyrolysis of coal in a fixed-bed reactor with or without internals were investigated. The results showed that the reaction time in the reactor without internals is approximately twice of the time in the reactor with internals. With utilization of internals to enhance heat transfer and regulate the pyrolysis gas flow direction inside the reactor, increasing the coal moisture content prolonged the time that required to heat up the coal at the bed center to the preset temperature and increased the light tar content, whereas the tar yield tended to first increase and then decrease and the yields of pyrolysis gas and water tended to increase. In contrast, there was not dramatic difference in the reactor without internals when varying the coal moisture. At a heating furnace temperature of 900℃, the increase of coal moisture from 0.41% to 11.68% (mass) increased the tar yield from 9.21% to 10.74% (mass) for the reactor with internals, but when the coal moisture content increased further to 15.93% (mass) the tar yield decreased to 10.26% (mass). The variation trend with coal moisture content in the average pyrolysis gas composition was similar for both reactors, and the higher heating value (HHV) became lower when the coal moisture increased.

Key words: coal pyrolysis, internals, coal moisture content, secondary reaction, reaction control

摘要：

通过在有无内构件(传热板和中心集气管)固定床反应器中研究不同水分含量煤的热解特性,考察了两反应器中煤料的升温特性、热解产物分布、焦油品质以及气体产物组成和半焦热值。结果表明,内构件可以强化传热和调节热解产物在反应器内的流动,相对无内构件反应器,有内构件反应器的反应时间缩短近一半。在有内构件反应器中,当煤水分增加,导致煤热解反应要求的时间延长,焦油中轻质组分(沸点低于360℃)含量明显升高,焦油收率先增加后降低,热解水和热解气产率升高,而无内构件反应器的热解产物无明显差异。当加热温度900℃时,煤水分从0.41%(本文中无特殊说明的均为质量分数) 增加至11.68%,焦油产率从9.21%增长到10.74%;当煤水分增加到15.93%,焦油产量下降到10.26%。两反应器气体平均组成随水分增加的变化趋势相似,气体热值均随水分增加呈下降趋势。

关键词: 煤热解, 内构件, 煤水分, 二次反应, 反应调控

CLC Number:

TQ536.1

HU Erfeng, ZHANG Chun, WU Rongcheng, FU Xiaoheng, XU Guangwen. Pyrolysis of coal with different moisture contents in fixed-bed reactorwith internals[J]. CIESC Journal, 2015, 66(7): 2656-2663.

胡二峰, 张纯, 武荣成, 付晓恒, 许光文. 内构件固定床反应器中不同水分煤的热解特性[J]. 化工学报, 2015, 66(7): 2656-2663.

References 22

[1]	Lemaignen L, Zhuo Y, Redd G P, et al. Factors governing reactivity in low temperature coal gasification (Ⅱ): An attempt to correlate conversions with inorganic and mineral constituents [J]. Fuel, 2002, 81 (3): 315-326.
[2]	Hanson S, Patrick J W, Walker A. The effect of coal particle size on pyrolysis and steam gasification [J]. Fuel, 2002, 81(5): 531-537.
[3]	Porada S. The influence of elevated pressure on the kinetics of evolution of selected gaseous products during coal pyrolysis [J]. Fuel, 2004, 83 (7/8): 1071-1078.
[4]	Yang Huimin. Effects of reaction atmospheres on the formation of gaseous products during coal pyrolysis [J]. Journal of Taiyuan University of Technology, 2010, 41 (4): 338-341.
[5]	Alonso M J G, Alvarez D, Borrego A G, et al. Systematic effects of coal rank and type on the kinetics of coal pyrolysis [J]. Energy & Fuels, 2001, 15 (2): 413-428.
[6]	Cui L, Lin W, Yao J. Influences of temperature and coal particle size on the flash pyrolysis of coal in a fast-entrained bed [J]. Chemical Research in Chinese Universities, 2006, 22 (1): 103-110.
[7]	Zhu W, Song W, Lin W. Effect of the coal particle size on pyrolysis and char reactivity for two types of coal and demineralized coal [J]. Energy & Fuels, 2008, 22 (4): 2482-2487.
[8]	Butuzova L, Razvigorova M, Krzton A, et al. The effect of water on the yield and structure of the products of brown coal pyrolysis and hydrogenation [J]. Fuel, 1998, 77 (6): 639-643.
[9]	Krebs V, Furdin G, Marêché J F, et al. Effects of coal moisture content on carbon deposition in coke ovens [J]. Fuel, 1996, 75 (8): 979-986.
[10]	Hayashi J I, Iwatsuki M, Morishita K, et al. Roles of inherent metallic species in secondary reactions of tar and char during rapid pyrolysis of brown coals in a drop-tube reactor [J]. Fuel, 2002, 81 (15): 1977-1987.
[11]	Yip K, Wu H, Zhang D. Effect of inherent moisture in collie coal during pyrolysis due to in-situ steam gasification [J]. Energy & Fuels, 2007, 21 (5): 2883-2891.
[12]	Zhang Chun. Coal pyrolysis for high-quality tar in fixed bed pyrolyzer enhanced with internals [J]. Energy & Fuels, 2013, 28 (1): 236-244.
[13]	Zhang C, Wu R, Hu E, et al. Coal pyrolysis for high-quality tar and gas in 100 kg fixed bed enhanced with internals [J]. Energy & Fuels, 2014, 28 (11): 7294-7302.
[14]	Shamsi A, Shadle L J, Seshadri K S. Study of low-temperature oxidation of buckskin subbituminous coal and derived chars produced in ENCOAL process [J]. Fuel Process Technology, 2004, 86 (3): 275-292.
[15]	Atwood M T, Schulman B L. The TOSCOAL process-pyrolysis of western coals and lignites for char and oil production [J]. Preprints of Papers American Chemical Society Division of Fuel Chemical, 1977, 22: 233-252.
[16]	Li Q, Li R, Ma Z, Chen J. New progress of the U.S. LFC technology of low rank coal upgrading with cogeneration of coal liquids [J]. China Min. Mag., 2010, 12 (2): 82-87.
[17]	Zhang J, Wu R, Zhang G, Yu J, Yao C, Wang Y, Gao S, Xu G. Technical review on thermochemical conversion based on decoupling for solid carbonaceous fuels [J]. Energy & Fuels, 2013, 27 (4): 1951-1966.
[18]	Eddinger R, Jones J, Blanc F. Development of the COED process [J]. Chem. Eng. Prog., 1968, 64 (10): 33-38.
[19]	Strom A, Eddinger R. COED plant for coal conversion [J]. Chem. Eng. Prog., 1971, 67 (3): 75-80.
[20]	Khan M R.A literature survey and an experimental study of coal divolatilization at mild and severe conditions: influence of heating rate, temperature and reactor type on products yield and composition [J]. Fuel, 1989, 68: 1522-1536.
[21]	Nagata M, Nishioka K, Yoshida S. A simulation model for the estimation of carbon formation on coke oven walls [J]. Ironmaking Conference Proc. AIME, 1985, 44: 355-362.
[22]	Wang Peng (王鹏), Wen Fang (文芳), Bu Xuepeng (步学朋), et al. Study on the pyrolysis characteristics of coal [J]. Coal Conversion (煤炭转化), 2005, 28 (1): 8-13.

Pyrolysis of coal with different moisture contents in fixed-bed reactorwith internals

内构件固定床反应器中不同水分煤的热解特性

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