酒精尾气回收工艺模拟与优化

研究从中药厂酒精尾气中回收酒精的吸收-解吸工艺。采用UNIFAC模型和Wilson模型分别预测吸收塔和解吸塔内的平衡关系,并对吸收塔和解吸塔内的工艺参数进行优化。结果表明：当吸收塔理论板数为25,液气比为0.24 L/m3,常温常压下操作时塔顶排气乙醇质量分数为28×10-6,塔釜乙醇回收率接近1;解吸塔为简单精馏塔,采用20块理论板,回流比为3,第10块板进料,塔顶可得91.7%的乙醇,塔釜得到几乎纯净的水,经冷却后作为吸收塔的吸收剂,循环套用。模拟结果对工业过程设计和设备改造具有一定指导意义。

Simulation and Optimization of Recycling Process for Exhaust Gas with Ethanol

The absorption-desorption process for recovery of ethanol from exhaust gas was studied by simulation with AspenPlus.UNIFAC model and Wilson model were selected for predicting equilibrium relationship of absorption tower and desorption tower respectively,meanwhile,the process parameters were optimized.The optimal parameters of towers were proposed： the theoretical total plate number of absorption tower is 25,the liquid gas ratio is 0.24 L/m3,the mass fraction of ethanol from overhead exhaust gas is 28×10-6 which is operated under room temperature and atmospheric pressure,the recovery rate of ethanol is close to 1 at column bottom.The theoretical total plate number of desorption tower is 20,the reflux ratio is 3,the raw material is fed at 10th plate.A top product of acetone with 91.7% concentration could be obtained and a bottom product of almost pure water can be recycling applied as absorbent water after cooling.These results are useful for construction design and improvement.