CO_2加氢制低碳烯烃反应中引入耦合反应的影响研究

The study of the effect of coupling reaction on light alkenes synthesis from CO_2 hydrogenation

针对CO2加氢制低碳烯烃反应的特点,考虑将气化反应引入到CO2加氢制低碳烯烃反应中。对无煤粉参与反应和有煤粉参与反应两种情况下的CO2加氢反应进行了热力学分析。采用总吉布斯自由能最小法计算得到不同温度下反应体系平衡组成及反应物的平衡转化率。对比两种情况下的计算结果表明,引入气化反应,平衡组成中烯烃含量和反应物H2转化率都提高了,而产物中H2O的含量降低了,表明有更多的氢储存到烃中,但反应物CO2的转化率降低了。此外,通过实验得到两种情况下CO2加氢反应产物分布,实验结果表明有煤粉参与的反应,烯烃选择性更高,但CO2转化率降低了,这与热力学分析所得结论一致。

According to the reaction feature of COx hydrogenation, the coal gasification is introduced to the reaction system of the light alkenes synthesis from CO2 hydrogenation. The thermodynamics analysis is carried out in the two systems of CO2 hydrogenation and CO2 hydrogenation with coal. The equilibrium compositions of reaction system and equilibrium conversions of tbe two cases are obtained by minimizing Gibbs free energy. The result shows that the content of the alkenes and the conversion of H2 improve, and the equilibrium composition of H2O is reduced, that is to say, more H2 is transferred to hydrocarbon. In addition, the product distribution is obtained by experiment for the two cases, which shows that the reaction of COx hydrogenation with coal has higher selectivity but low CO2 conversion. This is consistent with the result of thermodynamics analysis.