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Title: Investigation on mechanism of coal liquefaction-hydrocracking of model compounds

Abstract

There is strong evidence for the existence of -O-CH{sub 2}- and -CH{sub 2}-CH{sub 2}-bridge linkages in coal, especially in low rank coals, so there is a close relationship between hydrocracking kinetic of model compounds and coal liquefaction. In a tube autoclave with the volume of 17 ml the hydrocracking experiments of six model compounds are carried out in the presence of tetralin. The results show that the stability order of six model compounds in hydrocracking is as follows: Ph-Ch{sub 2}-Ph > Ph-O-Ph > Ph-Ch{sub 2}-Ch{sub 2}-Ph > Ph-O-CH{sub 2}-Ph > Ph-CH{sub 2}-S-CH{sub 2}-Ph > Ph-CH{sub 2}-S-S-CH{sub 2}-Ph. Introducing 10% (in weight) of benzyl phenyl ether can increase the decomposition ratios of diphenyl methane and diphenyl ether from 4.3% to 12.6% and 18.3% to 31.5% respectively. From the hydrocracking kinetic experiments for both benzyl phenyl ether (BPE) and dibenzyl (DB), the reaction corresponds to first order. The apparent activation (DE) is 83.9 kJ/mol for BPE and 150 kJ/mol for DB in the range of temperature 330--450 C, that is, the same as coal liquefaction. The influence of initial hydrogen pressure on hydrocracking of model compounds is also described in this paper. Under the conditions of the experiments the decomposition ratios (DR)more » of model compounds increase linearly with the increase of initial hydrogen pressure, e.g., DR is only 34.3% under 3.0 MPa (420 C), but 56.8% can be obtained when the initial hydrogen pressure reaches 8.5 MPa. Moreover, changing the initial pressure can influence not only DR of model compounds but also their hydrocracking mechanisms. Applying Mo-Ni, Y- and 5A-sieves to hydrocracking of model compounds are all effective. For more stable compounds such as dibenzyl methane and diphenyl ether the Y-sieve is better than the Mo-Ni catalyst, but it is just contrary to crack for benzyl phenyl ether.« less

Authors:
 [1]; ;  [2];  [3]
  1. Tongji Univ. (China)
  2. East China Univ. of Science and Technology (China)
  3. Inst. of Chemical and Fuel (Germany)
Publication Date:
OSTI Identifier:
324705
Report Number(s):
CONF-970931-
TRN: IM9911%%402
Resource Type:
Conference
Resource Relation:
Conference: 14. annual international Pittsburgh coal conference and workshop: clean coal technology and coal utilization, Taiyuan (China), 23-27 Sep 1997; Other Information: PBD: 1997; Related Information: Is Part Of Fourteenth annual international Pittsburgh coal conference and workshop: Proceedings; PB: [1500] p.
Country of Publication:
United States
Language:
English
Subject:
01 COAL, LIGNITE, AND PEAT; COAL LIQUEFACTION; CHEMICAL REACTION KINETICS; POLYPHENYLS; HYDROCRACKING; STABILITY; HYDROGEN; ACTIVATION ENERGY; PRESSURE DEPENDENCE

Citation Formats

Wu, J Z, Gao, J S, Hang, Y Z, and Oelert, H H. Investigation on mechanism of coal liquefaction-hydrocracking of model compounds. United States: N. p., 1997. Web.
Wu, J Z, Gao, J S, Hang, Y Z, & Oelert, H H. Investigation on mechanism of coal liquefaction-hydrocracking of model compounds. United States.
Wu, J Z, Gao, J S, Hang, Y Z, and Oelert, H H. 1997. "Investigation on mechanism of coal liquefaction-hydrocracking of model compounds". United States.
@article{osti_324705,
title = {Investigation on mechanism of coal liquefaction-hydrocracking of model compounds},
author = {Wu, J Z and Gao, J S and Hang, Y Z and Oelert, H H},
abstractNote = {There is strong evidence for the existence of -O-CH{sub 2}- and -CH{sub 2}-CH{sub 2}-bridge linkages in coal, especially in low rank coals, so there is a close relationship between hydrocracking kinetic of model compounds and coal liquefaction. In a tube autoclave with the volume of 17 ml the hydrocracking experiments of six model compounds are carried out in the presence of tetralin. The results show that the stability order of six model compounds in hydrocracking is as follows: Ph-Ch{sub 2}-Ph > Ph-O-Ph > Ph-Ch{sub 2}-Ch{sub 2}-Ph > Ph-O-CH{sub 2}-Ph > Ph-CH{sub 2}-S-CH{sub 2}-Ph > Ph-CH{sub 2}-S-S-CH{sub 2}-Ph. Introducing 10% (in weight) of benzyl phenyl ether can increase the decomposition ratios of diphenyl methane and diphenyl ether from 4.3% to 12.6% and 18.3% to 31.5% respectively. From the hydrocracking kinetic experiments for both benzyl phenyl ether (BPE) and dibenzyl (DB), the reaction corresponds to first order. The apparent activation (DE) is 83.9 kJ/mol for BPE and 150 kJ/mol for DB in the range of temperature 330--450 C, that is, the same as coal liquefaction. The influence of initial hydrogen pressure on hydrocracking of model compounds is also described in this paper. Under the conditions of the experiments the decomposition ratios (DR) of model compounds increase linearly with the increase of initial hydrogen pressure, e.g., DR is only 34.3% under 3.0 MPa (420 C), but 56.8% can be obtained when the initial hydrogen pressure reaches 8.5 MPa. Moreover, changing the initial pressure can influence not only DR of model compounds but also their hydrocracking mechanisms. Applying Mo-Ni, Y- and 5A-sieves to hydrocracking of model compounds are all effective. For more stable compounds such as dibenzyl methane and diphenyl ether the Y-sieve is better than the Mo-Ni catalyst, but it is just contrary to crack for benzyl phenyl ether.},
doi = {},
url = {https://www.osti.gov/biblio/324705}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Wed Dec 31 00:00:00 EST 1997},
month = {Wed Dec 31 00:00:00 EST 1997}
}

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