双再沸器透热精馏的节能优化

Energy-saving Optimization of Diabatic Distillation With Two Reboilers

以正丙醇-异丙醇体系为例,研究了双再沸器透热精馏操作。在该操作中,精馏塔的提馏段增设了一个中间再沸器,与塔釜再沸器一起共同分担精馏塔的热负荷。通过单因素分析和非线性拟合对相关工艺参数进行了模拟优化,并对相应操作的热力学性能和分离性能的变化进行了分析。最终优化结果表明:达到相同的分离效果,双再沸器透热精馏相较于绝热精馏有效能损失降低了29.4%。双再沸器透热精馏通过热量的合理分配,降低对热源的品位要求,提高能量利用率,最终达到节能目的。

The diabatic distillation with two reboilers was studied by separating a binary mixture of n-propanol and isopropanol as an example. In this operation, a jacketed inter-reboiler was set in the stripping section of the rectification tower. The heat duty of the tower was shared together by the inter-reboiler and the bottom reboiler. The single-factor analysis and non-linear fitting method were used to simulate and optimize the relevant process parameters of the proposed operation. The thermodynamic performance and separation performance of the scheme under the corresponding conditions were analyzed. The results showed that the exergy loss of the diabatic distillation with two reboilers was reduced by 29.4% as compared to that of adiabatic distillation when they had the same separation performance. The diabatic distillation with two reboilers achieved energy saving by rationally energy distribution, the energy quality reduction of heat sources, and the improvement of energy-using efficiency.