基于MINLP模型的焦化废水蒸氨塔操作优化

Optimization of Distillation Operation for Coking Wastewater Treatment Based on MINLP Model

以精馏塔基本的精馏逐级严格衡算方程为基础,增加反映氨水收益、公用工程价格、生化处理成本、再沸器加热方式和预热器热集成等影响蒸氨塔操作的参数和变量,建立了以操作费用最低为目标的适宜焦化废水蒸氨塔操作的非线性整数规划优化模型.结果表明,在生化处理成本为11.17$/t条件下,污水入口浓度、出口浓度、塔板数和预热器热效率均可显著影响蒸氨塔的操作,但直接蒸汽加热蒸氨塔处理成本比间接蒸汽加热低1.56$/t.前者的蒸氨塔操作费用最低的氨水出口浓度为300 mg/L,总塔板数为25,预热器热效率为65%,最佳进料温度为75.40℃.

A mixed integer nonlinear programming model for ammonia-water distillation column is set up based on rigorous MESH equation in order to minimize the operation cost of the column for obtaining the corresponding optimal operating parameters. In this model, utilities price, bio-treatment cost, heating type of the column and heat integration of the preheater are considered as the key factors affecting the column operation cost, while feed inlet temperature and location, and corresponding utilities flow rates are defined as the key operating parameters. The results indicate that direct heating column can save 1.56 ￥/t, compared with indirect one. The sensitive analysis shows that the parameters such as inlet and outlet concentrations of ammonia, total stage number, utilities price, and preheater efficiency have significant effect on the operation of the distillation column. For a direct heating column, the optimal operating conditions are outlet concentration at 300 mg/L, total stage number 25, preheater efficiency 65%, and feed inlet temperature 75.40 ℃.