粗甲醇精馏系统技改的模拟计算及BHS型填料的应用

将100 kt/a甲醇生产装置粗甲醇精馏系统由双塔流程改造为三塔双效精馏流程,即在利旧的基础上增加1座加压塔。运用Aspen Plus软件对新流程各塔进行了模拟优化,模拟优化结果为:新增加压塔的理论板数N=38,进料位置NF=26,回流比R1.6;其余2座塔进料位置NF分别为15和28,回流比R分别为0.6和1.5。以BHS型填料的结构特点及填料层压降数学模型为基础,完成了对新增加压塔的设计参数的计算。在此基础上,对技改前、后的流程进行了静态模拟及对比研究,结果表明:三塔双效精馏流程可使精甲醇质量分数达99.9%以上,年节省水蒸气和循环水分别为48 kt和2 936 kt,年可从废水中回收甲醇658.82 t,年增经济效益2 837.1万元。

Simulation Calculation of Technological Transformation Measures for Crude Methanol Rectification System and Use of BHS Packing

The crude methanol rectification system of 100 kt/a methanol production plant is to be revamped from dual-tower process to three-tower dual-effect rectification process , that is to add a pressure tower on the basis of using spare equipment .The software Aspen Plus is used to simulate and optimize each tower in new process , the simulation and optimization results are： for the new added pressure tower, theoretical plate number N=38, feeding location NF =26, and reflux ratio R〉1.6;for the rest two towers, the feeding locations NF are 15 and 28, and reflux ratio R are 0.6 and 1.5 respectively .Based on structural features of BHS packing and mathematical model of packing layer pressure drop , the design parameters calculation of the new added pressure tower is accomplished .On that basis , static simulation of processes before and after technical renovation and comparison study are carried out , results show that with three-tower dual-effect rectification process , methanol mass fraction can reach above 99.9%, the annual saving of steam and circulating water are 48 kt and 2 936 kt respectively, methanol recovered from waste water is 658.82 t, the increase of economic benefit is 28 .371 million annually .