无累积罐循环全回流操作的模拟研究

间歇精馏循环全回流操作是一种具有前景的新型操作方式。文中在循环全回流操作的基础上,首次提出了无累积罐循环全回流新操作方式。通过数学模型对其进行模拟,模拟计算比较了新方式、恒回流比间歇操作和塔顶储罐一次全回流操作3种操作方式。模拟结果表明:无累积罐新操作方式的全回流阶段时间由2个因素决定,全回流开始时精馏塔内的浓度梯度情况和精馏塔内持液的平均浓度。随着全回流-全采出操作的进行,后续循环中的全回流阶段的时间增加,全采出阶段时间减少。当进料浓度低时,新操作方式的分离效率比恒回流比方式高26.4%—30.1%,并通过模拟揭示了新操作方式的特点。研究表明:无累积罐循环全回流操作方式是一种新型高效的分离操作。

Simulation of cyclic total reflux batch distillation without reflux drum

Cyclic total reflux operation is a promising operation mode.A new operation mode,i.e.the cyclic total reflux operation without reflux drum,was proposed for the first time.A mathematical model verified by experiment was used for the calculation.The newly proposed cyclic operation was compared with constant reflux operation and total reflux operation with one reflux drum.The simulation results show that the total reflux period is determined by two elements: the concentration profile when the operation begins and the average concentration in the distillation column.The results reveal that when the feeding concentration is low,the separation efficiency of cyclic total reflux operation without reflux drum is 26.4%-30.1% higher than that under regular constant reflux operation in batch distillation.