热集成变压精馏分离吡啶-水的工艺模拟与优化  

Process simulation and optimization of heat-integrated pressure swing distillation system for pyridine-water separation

作　　者：辛燕平[1] 赵明 夏铭[1] 许春建[1] 

机构地区：[1]天津大学化学工程国家重点实验室,天津300072 [2]华陆工程科技有限责任公司,陕西西安710065

出　　处：《化学工程》2014年第5期1-5,共5页Chemical Engineering(China)

摘　　要：基于吡啶-水体系的共沸组成对压力变化敏感,提出了热集成变压精馏的新工艺。新工艺采用冷凝器-再沸器式热集成,利用高压塔塔顶蒸汽加热低压塔再沸器,以节省能耗和操作费用。选择NRTL活度方程为物性计算模型,使用Aspen Plus软件对该工艺流程进行严格稳态模拟。为了获得经济最优的工艺条件,提出了局部经济优化和全局经济优化相结合的优化方案,并建立了优化迭代流程。优化结果显示:当低压塔和高压塔的操作压力分别为16 kPa和1 200 kPa,总理论板数分别为12和14,新鲜原料和循环物流分别从低压塔第9块板和从第6块板进料,高压塔的物流进料位置为第8块板,高压塔质量回流比为0.59时,年度总费用(TAC)最小。与常规的变压精馏工艺相比,热集成变压精馏工艺更加节能经济,可以节约能耗43.52%,节省年度总费用40.70%。A new method for pyridine-water separation was presented by using heat-integrated pressure swing distillation since the azeotropic compositions change significantly with pressure. Condenser-reboiler type heat integration was used between the condenser in high pressure distillation column and the reboiler in low pressure distillation column to save energy and operating costs. NRTL activity model was chosen as the property package in the simulation. Rigorous steady state simulations were implemented by means of commercial software Aspen Plus. To obtain the optimized configurations for this process,an optimization scheme combining partial economical optimization with global economical optimization was proposed. Sequential iterative optimization procedure was presented to facilitate the optimization. The optimal operating pressures for the two columns are 16 kPa and 1 200 kPa,respectively. The optimal total numbers of stages for low pressure distillation column and high pressure distillation column are 12 and 14,respectively. The fresh feed stream and recycle stream are fed into low pressure distillation column from stages 9 and 6. The feed location of high pressure distillation column is stage 8. The optimal mass reflux ratio of high pressure distillation column is 0. 59. Compared with the corresponding traditional pressure swing distillation scheme,heat-integrated pressure swing distillation scheme is more energy-saving and economical,with energy decreased by 43. 52% and total annual cost（ TAC） decreased by 40. 70%.

关 键 词：吡啶 水 热集成 变压精馏 模拟 优化 

分 类 号：TQ028.31[化学工程]