甲苯二异氰酸酯光气回收系统的扩产改造

Process improvement for phosgene recover system in toluene diisocyanate production

为了提高原甲苯二异氰酸酯(TDI)光气回收系统生产负荷,解决进料光气、惰性气体含量增加导致操作不稳定问题,采用Aspenplus软件对系统的甲苯吸收塔、甲苯解吸塔和甲苯精制塔进行了模拟分析和优化,考察了理论板数、进料位置、中间冷却器、塔径等影响因素,提出了保留原甲苯吸收塔和甲苯精制塔,新设计了甲苯解吸塔。原甲苯吸收塔增加2个中间冷却器、改变部分物料进料位置,新增塔代替原甲苯精制塔提馏段等措施,提高了生产负荷和操作稳定性,降低了设备投资费用。

To enlarge the capacity of the phosgene recover system of toluene diisocyanate （TDI） production and improve the operational stability with the increase of phosgene and inert gas feed content, the toluene absorption tower, the desorption tower and toluene purification tower are simulated and analyzed using Aspen pnls software. Various factors containing theoretical tray number,middle-cooler, column diameter are investigated and optimized. Existing toluene absorption tower and purification tower are retained. A new tower is designed for the toluene desorption. For the toluene absorption tower, additions of two middle coolers and feed position modification of some streams are proposed. A new distillation tower is designed to replace the stripping section of the toluene purification tower. These treatments improve the system load and operational stability and save the capital investment.