甲醇制烃（MTH）反应热力学研究

对甲醇制烃反应体系进行了热力学分析,计算了不同温度下各反应的焓变、吉布斯自由能变和反应平衡常数,采用平衡常数联立方程法估算了甲醇转化生成C2-C10烃的热力学平衡组成.计算结果表明：甲醇制烃为强放热反应,1 mol甲醇转化最大放热量约为90 kJ/mol;甲醇制烃体系中除甲醇脱水之外,大部分反应均可视为不可逆过程;高温低压不利于烷烃生成物,有利于芳烃和烯烃生成物.对计算结果与实验结果进行了比较,数据变化趋势较为一致.计算结果表明,甲醇制烃体系不受热力学的控制,催化剂的选择和反应条件的选择至关重要.

Thermodynamic study on methanol conversion to hydrocarbons(MTH)

Abstract: Thermodynamic analysis of methanol to hydrocarbons system has been carried out. Enthalpy change , Gibbs free energy change and equilibrium constant at different temperatures were calculated for each reaction. Thermodynamic equilibrium compositions of the C2-10 hydrocarbons products were estimated by the method of simultaneous equations of equilibrium constant. The results indicated that the process of methanol to hydrocarbons involves strong exothermic, the maximum heat release is up to 90 kJ/mol for 1 mol methanol conversion; In the reaction system, most of reactions could be taken as irreversible processes except methanol dehydration; High temperature and low pressure are adverse to alkanes, but favor to the olefins and aromatics to a certain extent. In our research, the change trend of caculated values is relatively consistent with that in experimental results. In actual MTH reaction process, the most important factor is not thermodynamics control but the choice of proper catalysts and reaction conditions.