Dimethyl carbonate(DMC) is a new kind of industrial product,which has extensively applied in different aspects. Special distillation is required to separate the mixture of DMC and methanol since methanol usually exists in the DMC product. Three special distillation configurations including extractive distillation,azeotropic distillation and pressure swing distillation were proposed to separate the DMC-MeOH azeotrope system. The steady-state simulations of the three processes were established by Aspen Plus,and the optimum parameters of the three processes with minimum energy requirement have been obtained using sensitive analyses. The simulation results showed that energy requirement of extractive distillation accounts for 29.0% of the pressure swing distillation and 30.2% of the azeotropic distillation respectively,which shows a good energy-saving potential. Control of extractive distillation process with minimum energy consumption was investigated using the Aspen Dynamics,and two control structures were proposed. The control structure with fixed reboiler duty/feed rate ratio was proposed based on the basic control structure,and the dynamic simulation results revealed that this control structure can handle feed flow rate and composition disturbances quite effectively.%作为一种新环保型化工产品,碳酸二甲酯近年来在各行业中得到了广泛应用.由于碳酸二甲酯产品中常含有与之形成共沸物的甲醇,因此需要特殊工艺对其进行分离.本文利用Aspen Plus软件建立了严格稳态模型,对比了萃取精馏、共沸精馏和变压精馏分离碳酸二甲酯-甲醇二元共沸物的3种分离工艺,并以系统能耗为目标进行单变量分析,得到最低能耗下的萃取精馏、共沸精馏、变压精馏工艺参数.稳态分析结果表明:萃取精馏过程能耗只占变压精馏的29.0%、占共沸精馏的30.2%,其节能优势明显.在此基础上,采用Aspen Dynamics软件对萃取精馏最佳工艺进行了控制研究,提出了两种控制结构.结果表明,含有固定再沸器/进料比例的改进控制结构能够有效地应对进料流量与进料组成扰动,保证碳酸二甲酯和甲醇产品纯度.
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