溶剂生产中醪塔的优化模拟

Simulation and Optimization of Prefractionator Operation in the Process of Solvent Production

针对丙酮—丁醇精馏工艺过程中醪塔分离性能差和能耗高的问题,提出了优化方案,增加了醪塔塔高,添加一个侧线采出位置.应用PRO/Ⅱ化工流程模拟软件对优化后的醪塔进行模拟,考察了醪塔理论板数、侧线采出位置、进料位置等因素对醪塔分离性能和蒸汽消耗量的影响.优化后经模拟确定了醪塔理论板数为40块,进料位置为第18块理论塔板处,侧线采出位置为第10块理论塔板处.该条件下,醪塔塔顶馏出物中水含量由47.09%降到13.23%;侧线采出产物轻相中丁醇的含量为73.07%,而优化前在醪塔塔顶产物中丁醇的含量为34.19%;能耗与原工艺相比降低了38.74%;醪塔塔釜废醪液中总溶剂含量降为0.013%.工业醪塔试车运行结果与模拟结果吻合良好.

An optimum scheme was proposed to solve the problems of the process of distillation for butanol-acetone, such as high heat duty and low separating efficiency ofprefractionator. The theoretical plate number ofprefractionator was increased. A side withdrawing position of prefractionator was added. The effect of theoretical plate number, feeding position and side withdrawing position on the separating efficiency and the steam consumption of prefractionator were simulated with PRO/Ⅱ software. The optimum operating parameters for new process were obtained. The theoretical plate number was 40. The feeding position was the 18th stage, the side withdrawing position was the 10th stage. Under the conditions, the mass fraction of water in overhend products decreased from 47.09% to 13.23%; the mass fraction of butanol in the light phase of side withdrawing products was 73.07%, but the mass fraction in overhead products before optimization was 34.19%; the steam consumptiom was saved by 38.74%, the mass fraction of solvent in column bottom was reduced to,0.013%. After optimization, the test running result of prefractionator showed good agreement with the simulation result.