BDO装置含醇废液中正丁醇回收的研究与模拟

Study and Simulation of Recovery of n-butanol from the Solutions Containing Alcohols in BDO Unit

正丁醇是重要的化工原料,炔醛法BDO生产工艺废水中含大量正丁醇、水及少量正丙醇与甲醇,加以回收会产生较好的经济效益。对某厂10×104t/a BDO生产装置的丁醇塔进行改造,并增加塔器及辅助设备,分离提纯正丁醇,利用Aspen Plus模拟软件对拟改造的流程进行模拟计算,其中精馏塔均采用RadFrac模型,换热器采用Heater模拟,层析器采用Decanter模型。模拟计算的灵敏板温度、关键点的流量及组成等关键参数均与实际值吻合,说明Aspen Plus软件可用于对拟改造工艺的模拟计算,确定该塔的塔板效率为0.95,塔板效率较高,故对其改造后,即使由于气液相变化导致塔板效率改变,亦可通过优化工艺参数达到分离要求。研究结果表明：该工艺流程可有效从BDO副产的杂醇溶液中分离回收正丁醇,且正丁醇回收率及产品质量可分别达到99.47%和99.60%,经初步计算,该企业每年可回收优等品正丁醇1.28×104t,年增产值7680万元。

N-butanol is an important chemical raw material.The waste water from Reppe BDO unit contains a large amount of n-butanol,water and a small amount of n-propanol and methanol,so good economic benefit can be produced by recovering the n-butanol.The butanol tower of a 100 kt/a BDO unit was modified,and towers and auxiliary equipment were installed to separate and purify n-butanol.Aspen Plus was used to simu-late the modified process flow.The RadFrac model was used to simulate the fractionator,the Heater was used to simulate the heat exchanger,and the Decanter model was used to simulate the decanter.The simulated key parameters such as the temperature of sensitive plate and the flow and composition of key points coincided with the actual values,indicating that Aspen Plus can be used to simulate the modified process.The tower efficiency was determined to be 0.95,so after modification,even if the tray efficiency will change due to the changes in gas-liquid phase,the separation requirements can be met by optimizing the process parameters.The research results showed that the process can effectively recover n-butanol from the solutions containing alco-hols in BDO unit,and the recovery rate and product purity of n-butanol can reach 99.47% and 99.60% respectively.Based on the preliminary calculation,the company can recover 12800 tons of premium n-butanol each year,and an annual increase of 76.8 million yuan in output value can be achieved.