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针对以碳酸二甲酯(DMC)和苯酚(PhOH)为原料、酯交换法合成碳酸二苯酯(DPC)化学反应平衡常数非常低的问题,从理论上研究了提高原料转化率的方法及反应器的选型。首先,从理论上分析和揭示了从反应系统移去产物甲醇是提高原料转化率的最重要途径;其次,在假定化学反应达到平衡的基础上,将原料转化率视作由组分浓度控制的蒸馏过程进行研究,比较分析了带冷凝器的CSTR反应器、反应蒸出塔和反应精馏塔三种情况下甲醇可达到的移出率及其对原料转化率的影响规律。结果表明,原料转化率同时受化学反应平衡、反应体积、汽液平衡条件和分离因素的限制,最理想的工艺是反应精馏塔,其中PhOH的转化率可达到29.71%。
Aiming at the problem that the equilibrium constants of chemical reaction of diphenyl carbonate (DPC) synthesized by transesterification method are very low with dimethyl carbonate (DMC) and phenol (PhOH) as raw materials, the methods and reactions for improving the conversion rate of raw materials are theoretically studied Selection of the device. First of all, it is theoretically analyzed and revealed that removing the product methanol from the reaction system is the most important way to improve the conversion rate of the raw materials. Secondly, based on the assumption that the chemical reaction is balanced, the conversion of the raw materials is regarded as controlled by the component concentration The process of distillation was studied. The reusable rate of methanol removal and its influence on the conversion rate of raw materials were compared under three different conditions: CSTR reactor with condenser, reaction distillation column and reaction distillation column. The results show that the conversion rate of raw materials is limited by chemical reaction equilibrium, reaction volume, vapor-liquid equilibrium conditions and separation factors. The optimal reaction process is the reactive distillation column, in which the conversion of PhOH can reach 29.71%.