Research on coal tar catalytic cracking over hot in-situ chars

LIU Shu-yuan; WANG Yin; WU Rong-cheng; ZENG Xi; XU Guang-wen

Volume 41 Issue 09

Sep. 2013

Turn off MathJax

Article Contents

Article Navigation > Journal of Fuel Chemistry and Technology > 2013 > 41(09): 1041-1049

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]. Journal of Fuel Chemistry and Technology, 2013, 41(09): 1041-1049.

Citation:

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]. Journal of Fuel Chemistry and Technology, 2013, 41(09): 1041-1049.

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]. Journal of Fuel Chemistry and Technology, 2013, 41(09): 1041-1049.

Citation:

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]. Journal of Fuel Chemistry and Technology, 2013, 41(09): 1041-1049.

PDF( 3151 KB)

Research on coal tar catalytic cracking over hot in-situ chars

1.
State Key Laboratory of Multi-phase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;
2.
University of Chinese Academy of Sciences, Beijing 100049, China;
3.
Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China

Received Date: 2012-12-24
Rev Recd Date: 2013-02-28
Publish Date: 2013-09-30

Abstract

Abstract

A comparison of coal tar catalytic cracking over hot char from in-situ coal pyrolysis and cooling char was investigated. The results show that the in-situ char has a higher capability of removing tar than the cooling char under the same reaction conditions. The tar content in the product gas is reduced to as low as 100 mg/m³ when the temperature of the in-situ char bed and the gas residence time in the bed are 1 100 ℃ and 1.2 s, respectively. BET analysis shows that the in-situ char has larger specific surface area and more micro pores than the cooling char, while the uniformity of the carbon crystallite structure in the cooling char increases, causing the decrease of the char's catalytic activity for tar removal. With the increase of gas residence time in the char bed or of cracking temperature, the tar content in the product gas decreases greatly, while the difference of catalytic activity for tar cracking between in-situ char and cooling char also decreases. The activity of the spent char is decreased significantly. However, the activity of the spent char can be basically recovered when it is partially gasified with steam.
- hot char,
- cold char,
- tar,
- catalytic cracking

FullText(HTML)

References(26)

References

BRAGE C, YU Q Z, CHEN G X, SJOSTROM K. Tar evolution profiles obtained from gasification of biomass and coal[J]. Biomass Bioenergy, 2000, 18(1): 87-91.

MILNE T A, EVANS R J. Biomass gasifier "tars": Their nature, formation, and conversion[R]. Colorado: Nrel, 1998.

HAN J, KIM H. The reduction and control technology of tar during biomass gasification/pyrolysis: An overview[J]. Renew Sust Energ Rev, 2008, 12(2): 397-416.

BAKER E G, MUDGE L K, BROWN M D. Steam gasification of biomass with nickel secondary catalysts[J]. Ind Eng Chem Res, 1987, 26(7): 1335-1339.

KINOSHITA C M, WANG Y, ZHOU J. Effect of reformer conditions on catalytic reforming of biomass-gasification tars[J]. Ind Eng Chem Res, 1995, 34(9): 2949-2954.

ARAUZO J, RADLEIN D, PISKORZ J, SCOTT D S. Catalytic pyrogasification of biomass. Evaluation of modified nickel catalysts[J]. Ind Eng Chem Res, 1997, 36(1): 67-75.

MIYAZAWA T, KIMURA T, NISHIKAWA J, KADO S, KUNIMORI K, TOMISHIGE K. Catalytic performance of supported Ni catalysts in partial oxidation and steam reforming of tar derived from the pyrolysis of wood biomass[J]. Catal Today, 2006, 115(1-4): 254-262.

DELGADO J, AZNAR M P, CORELLA J. Calcined dolomite, magnesite, and calcite for cleaning hot gas from a fluidized bed biomass gasifier with steam: Life and usefulness[J]. Ind Eng Chem Res, 1996, 35(10): 3637-3643.

DELGADO J, AZNAR M P, CORELLA. Biomass gasification with steam in fluidized bed: Effectiveness of CaO, MgO, and CaO-MgO for hot raw gas cleaning[J]. Ind Eng Chem Res, 1997, 36(5): 1535-1543.

HOSOKAI S, NORINAGA K, KIMURA T, NAKANO M, LI C Z, HAYASHI J. Reforming of volatiles from the biomass pyrolysis over charcoal in a sequence of coke deposition and steam gasification of coke[J]. Energy Fuels, 2011, 25(11): 5387-5393.

CHEMBUKULAM S K, DANDGE A S, KOVLLU RAO N L, SESHAGIRI K, VAIDYESWARAN R. Smokeless fuel from carbonized sawdust[J]. Ind Eng Chem Prod Res Dev, 1981, 20(4): 714-719.

HOSOKAI S, HAYASHI J, SHIAMADA T, KOBOYASHI Y, KURAMOTO K, LI C Z, CHIBA T. Spontaneous generation of tar decomposition promoter in a biomass steam reformer[J]. Ind Eng Chem Res, 2005, 83(9): 1093-1102.

BRANDT P, LARSEN E, HENRIKSEN U. High tar reduction in a two-stage gasifier[J]. Energy Fuels, 2000, 41(4): 816-819.

HOSOKAI S,KISHIMOTO K,NORINAGA K, LI C Z, HAYASHI J. Characteristics of gas-phase partial oxidation of nascent tar from the rapid pyrolysis of cedar sawdust at 700-800℃[J]. Energy Fuels, 2010, 24(5): 2900-2909.

ABU E-R Z, BRAMER E A, BREM G. Experimental comparison of biomass chars with other catalysts for tar reduction[J]. Fuel, 2008, 87(10-11): 2243-2252.

HAYASHI J I, IWATSUKI M, MORISHITA K, TSUTSUMI A, LI C Z, TADATOSHI C. 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(5): 1977-1987.

ZENG X, WANG Y, YU J, WU S S, ZHONG M, XU S P, XU G W. Coal pyrolysis in a fluidized bed for adapting to a two-stage gasification process[J]. Energy Fuels, 2011, 25(3): 1092-1098.

ZENG X, WANG Y, YU J, WU S S, ZHONG M, XU S P, XU G W. Gas upgrading in a downdraft fixed-bed reactor downstream of a fluidized-bed coal pyrolyzer[J]. Energy Fuels, 2011, 25(11): 5242-5249.

HENRIKSEN U, AHRENFELDT J, JESEN T K, GOBEL B, BENTZEN J D, HINDSGAUL C, SORENSEN L H. The design, construction and operation of a 75 kW two-stage gasifier[J]. Energy, 2006, 31(10-11): 1542-1553.

GILBERT P, RYU C, SHARIFI V, SWITHENBANK J. Tar reduction in pyrolysis vapors from biomass over a hot char bed[J]. Bioresource technology, 2009, 100(23): 6045-6051.

SENNECA O, SALATINO P, MASI S. Microstructure changes and loss of gasification reactivity of char upon heat treatment[J]. Fuel, 1998, 77(13): 1483-1493.

FENG B, BHATIA S K, BARRY J C. Structural ordering of coal char during heat treatment and its impact on reactivity[J]. Carbon, 2002, 40(4): 481-496.

SHARMA A, KADOOKA H, KYOTANI T, TOMITA A. Effect of micro structural changes on gasification reactivity of coal chars during low temperature gasification[J]. Energy Fuels, 2002, 16(1): 54-61.

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.

SENNECA O, SALATINO P, MASI S. Heat treatment-induced loss of combustion reactivity of a coal char: The effect of exposure to oxygen[J]. Exp Therm Fluid Sci, 2004, 28(7): 735-741.

SHENG C D. Char structure characterized by Raman spectroscopy and its correlations with combustion reactivity[J]. Fuel, 2007, 86(15): 2316-2324.

Relative Articles

Supplements(0)

Cited By

Proportional views