甲醇制低碳烯烃反应体系的热力学计算与分析

采用原子矩阵法确定了甲醇制低碳烯烃独立的反应数,采用Gibbs自由能最小化方法,建立了计算烯烃产物之间平衡关系的数学模型,简化了计算过程。计算了甲醇制低碳烯烃各独立反应的Gibbs自由能及烯烃产物之间的平衡关系。热力学分析表明,甲醇制低碳烯烃反应主要为动力学控制,提高反应温度、降低反应压力和加水有利于乙烯平衡组成增加和乙烯与丙烯总平衡组成的增加,丙烯平衡组成随温度、压力变化存在最大值。计算数据与文献值比较表明,该法计算结果可靠,对甲醇制低碳烯烃的实验室研究及工业化生产有指导意义。

Thermodynamic Calculation and Analysis of Methanol to Olefins (MTO)

In order to simplify calculation process,the method of atomic matrix was applied to determine independent reactions of methanol to olefins reaction,and the method of Gibbs free energy minimization to establish mathematical model of calculating the equilibrium relation among the main olefin products for methanol to olefins reaction.The Gibbs free energy of independent reactions and the equilibrium relation among the main olefin products were focused and calculated.The results,which were obtained by thermodynamic analysis showed that methanol to light olefins was mainly controlled by kinetics.Reaction temperature raise,pressure reduction and water addition could improve ethylene equilibrium component and equilibrium component of ethylene and propylene,and propylene equilibrium composition existed maximum as temperature or pressure changes.The comparison between the calculation data and literature data show that the results of calculation are reasonable,and very important for experimental research and scale up of the process.