高气速选择性分离氨碳混和气模拟实验

Simulation Test on High Gas Velocity Selective Separation of NH_3/CO_2 Mixed Gas

采用二级串联鼓泡吸收器对NH3 /CO2 摩尔比为 2∶1的混和气体进行高气速选择性吸收 ,获得氨的总吸收率为 96 .7% ,二氧化碳的总吸收率为 33.1% ,二级吸收器出口气相CO2 摩尔含量达 90 .9% ,液相氨碳摩尔比为 5 .85。将此吸收液在加压下精馏分离氨 ,基本可以把吸收液中游离氨回收。分离游离氨后的溶液在常压下进行解吸 ,蒸馏塔出口液体含NH3 和CO2 量仅为 0 .0 14 %和 0 .0 0 6 % ,解吸气回串联吸收器进行循环吸收分离。对预计工业分离过程进行物料和能量衡算 ,分离 1kg液氨需 1MPa的蒸汽约 3.2kg。

Selective absorption under high gas velocity is carried out on a mixed gas with NH 3/CO 2 in a mole ratio of 2∶1 in two bubbling absorbers in series, the total absorption factor of ammonia is 96.7%, that of carbon dioxide is 33.1%, the mole content of CO 2 in the gas phase at the outlet of the second stage absorber reaches 90.9% and the mole ratio of NH 3/CO 2 in the liquid phase is 5.85. The absorption liquid is rectified under pressure to separate out ammonia, thereby recovering practically all free ammonia from the absorption liquid. Then, the liquid is desorbed at atmospheric pressure, the liquid at the exit of the distilling tower contains only 0.014% of ammonia and 0.006% of CO 2, and the desorbed gas is returned to the absorbers in series for circulating absorption and separation. The material and energy balance is calculated for the expected industrial separation, and the separation of 1kg of liquid ammonia requires 3.2 kg of steam at 1 MPa.