对二甲苯吸附分离工艺改进研究

摘要

The model of simulated moving bed(SMB)for para-xylene separation by adsorption was established. The influence of the bed number ratio in each functional zone,the void volume between beds,and the total bed number on adsorption performance was investigated. Results showed that the op-timized ratio of the bed number in adsorption zone over that in the purification zone is in the range of 0. 5—0. 7;the optimized ratio of the bed number in desorption zone/the purification zone is in the range of 0. 4—0. 5. The suitable ratio for buffer zone over total bed number is 8. 5%-13. 0%. Increasing the total bed number and decreasing the void volume can improve the separation efficiency of the process. Test results indicated that the optimized bed numbers in each zone(desorption,purification,ad-sorption,and buffer zone)is 3,7,4,2. This configuration reduces the number of adsorbent bed and adsorption tower under the premise of basically the same process performance.%建立了模拟移动床吸附分离对二甲苯过程的模型,研究吸附塔各功能区床层数比例、床层间空体积比例及床层总数对过程吸附性能的影响.研究结果显示:吸附区和脱附区与提纯区床层数的适宜比例分别为0. 5~0. 7和0. 4~0. 5;缓冲区占总床层数的适宜比例为8. 5%~13%;吸附剂床层总数的增加及床层间空体积的降低,可以提高分离效率.根据研究结果提出改进工艺的方案为16(3-7-4-2)床层;该方案在基本保持工艺性能前提下减少了吸附剂床层和吸附塔数量.