高压复杂物系化学平衡计算——由合成气制低碳醇的热力学分析

A New Method for Calculation of Chemical Equilibrium of Complex System——Thermodynamic Analysis of the Process from Synthetic Gas to Lower Alcohol

本文提出了一种计算高压复杂物系化学平衡的新方法。对由CO/H_2合成低碳醇的反应过程的化学平衡进行了计算。结果表明,平衡产物中的CH_4、CO_2、H_2O的产率占有绝对优势。在醇类中,甲醇的平衡产率最大。并且,H_2/CO摩尔比对平衡产率影响很大。

In this paper, a new method for calculating the chemical equilibrium of complex system was proposed.The new method was applied to the synthesis of alcohol from synthetic gas. The system contains nine independent reactions. The results show that equilibrium yield decreases as CH_4>H_2OCO_2>alcohols—C_2+hydrocarbon, while in alcohols, the order is CH_3OH>C_2H_5OH>C_3H_7OH, in C_(2^+) hydrocarbons, alkane>alkene with same carbon number, C_(2^+) hydrocarbons>C_(2^+) alcohols, C_1 products(?)C_2 products. Elevated temperature will reduce the euilibrium conversion of the reactant and yield of CH_4 and H_2O, but increase yield of alcohols and Cv_(2^+) hydrocarbons. The equilibrium yield of all the possible products, except for CO_2, will be enhanced at higher pressure, but the alcohol selectivity is greatly dependent on the pressure. Higher pressure leads to increase the alcohol equilibrium yield significantly.Increasing the mole ratio of H_2/CO, the equilibrium yield of CH_4, CH_3OH and H_2O reaches a maximum respectively. Methanol is the main product in alcohol fraction. The H_2/CO ratio has a great effect on equilibrium vield