Abstract: To know more about the application scope of heat-integrated distillation technology and acquire optimal column schemes, based on four binary systems with increasing relative volatility, the conventional distillation column and four heat-integrated distillation column configurations (a vapor recompression distillation column, an ideal internally heat-integrated distillation column, a simplified internally heat-integrated distillation column, a pressure-swing thermal-coupled distillation column) were optimized for minimizing total annual cost in this work with Aspen Plus. The heat-integrated distillation columns would show lower energy consumption and better economic performance when separating mixtures with close relative volatility, among which the vapor recompression and pressure-swing thermal-coupled distillation columns were the most promising ones. The conventional distillation column was an appropriate choice for mixtures of which relative volatility was relatively large. In addition, as payback period decreased, the economic advantage of heat-integrated distillation columns would also drop compared to the conventional distillation column.

Key words: relative volatility, heat-integrated distillation, energy consumption, total annual cost

摘要： 为了进一步了解热耦合精馏工艺的适用范围,同时寻找其中经济性较优的工艺流程,本文利用Aspen Plus流程模拟软件,针对相对挥发度依次递增的四组二元物系(苯-氟苯、苯-正庚烷、苯-甲苯、苯-氯苯)分别开展了常规精馏和4种热耦合精馏工艺(热泵精馏塔、理想内部热耦合精馏塔、内部热耦合精馏塔简化构型、差压热耦合精馏塔)的模拟研究,过程优化的目标函数为年均总费用最低。通过优化结果的对比可知,热耦合精馏工艺在分离相对挥发度较小的物系时能耗相对较低,经济性相对较好,其中又以热泵精馏塔和差压热耦合精馏塔的效果最为显著;而在相对挥发度较大的物系分离中,常规精馏则是较为合适的工艺选择。此外,随着投资回收期的减小,热耦合精馏工艺相对于常规精馏工艺的优势也有所下降。

关键词: 相对挥发度, 热耦合精馏, 能耗, 年均总费用