丁烯/甲醇耦合反应制乙烯、丙烯的热力学

本文通过热力学计算，得到各温度点下丁烯裂解/甲醇转化制乙烯、丙烯各反应的平衡常数和反应热，并分析了反应温度、原料组成对丁烯/甲醇耦合反应化学平衡的影响情况。计算结果表明甲醇脱水转化成烃的平衡常数非常大，远高于丁烯裂解反应；丁烯裂解的产物分布受反应温度的影响程度大于甲醇转化和丁烯/甲醇耦合反应；在甲醇反应中引入丁烯，可提高乙烯、丙烯含量及P/E（mol/mol），还可强化升温对甲醇反应的抑制作用；耦合反应中提高原料中丁烯含量对甲醇转化有一定的促进作用，而且丁烯的裂化情况对乙烯、丙烯收率起到决定性作用，尤其是高温条件下。

THERMODYNAMICS ON COUPLED CONVERSION OF BUTENE AND METHANOL TO ETHYLENE AND PROPYLENE

Equilibrium constants and reaction heats of several reactions about butene cracking and methanol conversion were obtained in this paper by thermodynamic calculation. Based on these data, influences of temperature and composition of feed on thermodynamic equilibrium mole fractions of components for coupled conversion of butene and methanol were discussed. Results calculated showed that equilibrium constants of methanol dehydration to olefins were far larger than those of butene cracking reactions. Temperature had more great effect to product distribution of butene cracking than methanol conversion and coupled conversion of butene and methanol. The yields of ethylene and propylene and the mole ratio of propylene to ethylene may all increase, and the inhibiting force of increasing temperature to methanol dehydration was intensified, when butene was introduced into methanol conversion. In addition, it can be concluded that, for coupled conversion of butene and methanol, the conversion of methanol could be promoted by increasing the content of buene in feedstock, and butene cracking played a crucial role in order to enhance yields of ethylene and propylene, especially at high temperature.