反应条件对CO甲烷化反应平衡及催化剂性能的影响

摘要

A thermodynamic analysis about the effects of temperature, pressure, and the composition of feed gas on CO metha-nation was carried out. The results indicate that low temperature, high pressure and a high H 2/CO molar ratio are favorable for the conversion of CO and CH4 selectivity. It was found that carbon deposition can be reduced by increasing reaction pressure, H2/CO mo-lar ratio and introducing steam into the feed gas. In addition, the impact of reaction conditions and composition of the feed gas on the performance of Ni-based catalysts were investigated experimentally. Experimental results show that the catalytic performance and the carbon deposition on the surface of catalysts were significantly affected by the reaction parameters, which is substantially consistent with thermodynamic analysis.%通过对CO甲烷化反应体系热力学计算，考察了反应条件和原料组成对平衡组成、平衡转化率以及CH4选择性和积炭的影响。计算结果表明，反应温度、压力、氢碳比和汽气比对CO平衡转化率、CH4选择性和积炭有明显影响，其中，低温、高压和高氢碳比有利于提高CO转化率和CH4选择性，而升高压力、增加氢碳比以及向原料气中加入水蒸气均能有效地减少积炭。另外，用Ni/MgO-Al2O3催化剂考察了反应条件和原料气组成对CO转化率、CH4选择性以及积炭的影响，实验结果，反应温度、压力、氢碳比和汽气比对催化剂的CO转化率、甲烷选择性以及积炭的影响明显，并与热力学平衡计算的结果基本一致。