Kinetics of nickel-catalyzed purification of tarry fuel gases from gasification and pyrolysis of solid fuels

被引:41
作者
Depner, H [1 ]
Jess, A [1 ]
机构
[1] Rhein Westfal TH Aachen, Inst Tech Chem & Makromol Chem, D-52074 Aachen, Germany
关键词
catalytic purification; tarry fuel gases; Ni-catalyst; naphthalene; benzene; methane; mass-transfer limitations;
D O I
10.1016/S0016-2361(99)00067-8
中图分类号
TE [石油、天然气工业]; TK [能源与动力工程];
学科分类号
0807 ; 0820 ;
摘要
As a contribution to develop a process for the chemical upgrading of tarry fuel gases, the kinetics of the catalytic conversion of hydrocarbons on a commercial nickel-catalyst in the presence of H-2 and H2O (Sud-Chemie, G 117) were studied. Besides single model hydrocarbons (naphthalene, benzene and methane) and their mixtures, a feed gas obtained by coal pyrolysis was catalytically converted. The experiments were performed in a tubular flow reactor at a total pressure of 160 kPa, a residence time with respect to the empty reactor up to 0.1 s and a particle diameter of 1.5 or 19 mm, varying with the temperature (450-1150 degrees C) and concentrations of H-2, H2O and the hydrocarbons. The influence of H2S and NH3 on the activity of the catalyst was also studied. The results indicate that the Ni-catalyst used is suitable to convert tarry fuel gases into a clean fuel or reduction gas, even if H2S is present. Although the rate of chemical reaction of the hydrocarbons on the Ni-catalyst is substantially reduced by hydrogen sulphide, a rest activity still remains, and all higher hydrocarbons are completely converted to CO, H-2 and CO2 at a temperature of about 1000 degrees C (0.3 vol% H2S; tau = 0.1 s). In contrast to H2S, NH3 has no influence on the conversion of hydrocarbons on the Ni-catalyst, and is just converted to N-2 and H-2. In a reactor of industrial scale, the overall reaction rate of hydrocarbon conversion is significantly affected by gas film diffusion (particle diameter: 19 mm), and is therefore only slightly influenced by H2S. (C) 1999 Elsevier Science Ltd. All rights reserved.
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页码:1369 / 1377
页数:9
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