外部热耦合技术在BTX分离中的应用

Application of the External Heat-Integration Technique in BTX Separation Process

外部热耦合式复合精馏塔将热量从高压塔的精馏段传向低压塔的提馏段,降低了分离操作的不可逆性,从而提高系统的热力学效率,降低系统所需的能耗。目前国内苯/甲苯/二甲苯(BTX)的分离技术仍然与国外先进水平相差很远,主要表现在系统的能耗高、工艺落后等方面。本文将外部热耦合技术应用到苯/甲苯/二甲苯的分离过程中,并用M athem atica软件对系统的设备投资和操作费用进行了仿真计算。结果表明,使用外部热耦合结构,系统节能幅度可达到37.94%,年度总费用降低达18.84%。

The externally heat-integrated double distillation columns was a process that involved heat integration between the rectifying section and stripping section of a high-and a low-pressure distillation columns,respectively.It can enhance the thermodynamic efficiency and reduce the energy consumption substantially.At present,the Benzene/Toluene/Xylene（BTX） separation technology was still lagging far behind the international advanced level,mainly in high energy consumption and outdated process,etc.The external heat-integration technique was applied to the Benzene/Toluene/Xylene（BTX） separation process,and a systematic simulation was made by Mathematica software.The results indicated that the externally heat-integrated double distillation columns can cut the energy consumption by 42.12%,as well as the TAC by 18.84% in comparison with their conventional counterpart.