Abstract: This research presented simulation and analysis of the dimethyl ether production process of one-step synthesis from syngas. This research presented a novel dimethyl ether production technology with multi-effect distillation and water as the absorbent. The energy consumptions of methanol and water were simulated and compared using Aspen Plus. The results showed that water was more energy efficient as the absorbent，reducing the total heat load by 23.54% and the total cooling load by 35.97% compared with methanol as the absorbent. From the perspective of energy saving，two-column and three-column separation processes were proposed according to different separation objectives. The results showed that the two-column separation process of methanol and water can increase the dimethyl ether production by 11.50%，without significant change in the energy consumption compared with the original production process. The three-column distillation process can reduce the cooling load by 45.07% and heat load by 19.27%，with an increase of 11.15% of the dimethyl ether production. The energy-saving effect of these new separation processes was remarkable.

Key words: dimethyl ether, simulation and optimization, multi-effect distillation

摘要： 二甲醚作为燃料的替代品，其生产开发在化学工程领域受到了广泛关注。本文对合成气一步法制备二甲醚过程进行了模拟分析，提出了用水作为吸收剂并采用多效精馏的二甲醚生产新工艺。利用Aspen Plus化工模拟软件对吸收塔进行模拟比较了甲醇和水作为吸收剂的能耗，模拟结果表明，用水吸收较甲醇吸收总热负荷降低23.54％，总冷负荷降低35.97％，更为节能。从节能降耗角度出发，根据不同的分离任务，提出了采用两塔分离甲醇-水及三塔分离甲醇-水的两项工艺改进措施。结果表明，采用两塔分离甲醇-水工艺比原工艺二甲醚产量增加了11.50%，能量消耗无明显变化。进一步采用三塔精馏工艺总冷负荷比原工艺减少45.07％，总热负荷减少19.27%，且二甲醚产量增加11.15％，节能效果显著。

关键词: 二甲醚, 模拟与优化, 多效精馏