高纯度酒精蒸馏中常见挥发性杂质的分离过程模拟

Simulation of familiar volatile impurities separation in high purity alcohol distillation process

酒精工业在国民经济中具有重要的地位,酒精产品广泛地应用于重要的工业部门,其中高纯度酒精具有严格的杂质含量控制,其产品主要用于涉及人体健康的食品、制药行业。本文以酒精5塔蒸馏工艺流程为基础,利用稳态流程模拟软件AspenPlus模拟高纯度酒精蒸馏过程,模拟结果与实际情况相当吻合,可为工艺流程的生产实践与诊断优化提供数据支持。通过流程中挥发性杂质的分布及运动情况阐述其传质过程,水洗塔利用酯、醛等轻物质在稀酒精中的强挥发性对其予以分离,精馏塔利用杂醇油物质的积聚性,通过塔中侧线抽取分离,甲醇塔利用浓酒精中甲醇与乙醇明显的挥发能力差异实现分离。由模拟可知,通过5塔蒸馏工艺可得到符合国家标准规定的高纯度酒精产品,但工艺并不能分离酒精发酵醪液中所有非目标组分。随着酒精产品贸易对象的拓宽,传统的5塔工艺需要进一步改进以适应新的要求。

Alcohol industry plays an important role in the national industry and alcohol products are widely used in important industrial sectors.With the strict control of impurities,high-purity alcohol is used to meet the demand of food and pharmaceutical industry.Based on the five-column distillation process,a steady state simulation of high purity alcohol distillation process is established by Aspen Plus.Conformed with the actual process data,the simulation results are able to provide references to the research of alcohol distillation process.According to the distribution and movement of the volatile substances in the distillation process,the mass transfer of impurity in distillation process is expatiated.Ester,aldehyde and other light substances are high volatility in dilute alcohol,consequently,are easier excluded in water-washing-column.Fusel oil substances are extracted through the side line stream because of their aggregations in distillation-column.Methanol and ethanol are separated in methanol-column on the basis of their significant differences in volatile in high ethanol concentration.The high-purity alcohol product which got through five-tower distillation process can measure up to the national standard,but not all the non-target components in fermentation mash can be removed by the process.With the expansion of alcohol product trade partners,the traditional five-column distillation should make improvements to satisfy the new requirements.