甲苯甲醇甲基化制二甲苯分馏系统节能工艺研究  

Study on energy saving technology for fractionation system of toluene methylation to Xylene

作　　者：贺来宾[1] 马丽丽[1] 杨卫胜[1] He Laibin;Ma Lili;Yang Weisheng(SINOPEC Shanghai Research Institute of Petrochemical Technology, Shanghai 201208)

机构地区：[1]中国石油化工股份有限公司上海石油化工研究院,上海市201208

出　　处：《炼油技术与工程》2018年第6期33-36,共4页Petroleum Refinery Engineering

摘　　要：以200 kt/a甲苯甲醇甲基化制二甲苯装置为研究对象,对装置能耗结构进行了计算分析。分析表明,装置主要的能耗为未反应的甲苯循环分馏所引起的燃料消耗,约占装置总能耗的64.6%。其中甲苯塔重沸炉消耗燃料气量约占燃料气消耗总量的86%,用于原料甲苯过热的进料加热炉燃料消耗约占14%。通过对分馏系统的模拟,分别计算了两塔常压分离、两塔加压分离和三塔分离3种分离工况,分析了各方案所需冷热公用工程消耗、蒸汽发生量以及综合能耗情况。结果表明:对于蒸汽供给充足的生产企业,可选择三塔分离方案,该方案不副产蒸汽,冷热公用工程消耗均最小,综合能耗120.4 kg/t(以kg/t表示千克标油每吨)甲苯进料,较优化前降低5.0%。而对于缺少蒸汽的生产企业,两塔加压分离方案更为适用,该方案可产生24.3 t/h蒸汽,且综合能耗最低,为93.7 kg/t甲苯进料,分离单元能耗降低26.0%。In a case study of a 200,000 TPY plant of toluene methylation to xylene, the energy consumptions of the unit are calculated and analyzed. The analysis shows that the main energy consumption of the unit is the fuel consumption of recycle fractionation of toluene which accounts to about 64.6% of the total energy consumption of the unit. The fuel consumption of toluene column reboiler is about 86% of the total fuel consumption, and the fuel consumption of the feed heating furnace used for toluene overheating is about 14%. Through the simulation calculation of fractionation system, the energy consumptions of two column normal pressure separation, two-column pressure separation and three-column separation are analyzed and discussed. The hot and cold utilities requirements, steam generation and energy consumptions of each process scheme are analyzed. The results show that the three-column separation process can be selected for the petrochemical plant with sufficient steam supply. In this scheme, no steam is produced, the consumption of cold and hot utilities is the lowest, and the energy consumption is about 120.4 kg/t toluene feed, which is about 5.0% lower than that before the optimization. For the petrochemical plant in which the steam is in short supply, the two column pressure separation scheme is more suitable. In this process, the steam production is 24.3 t/h and energy consumption is the lowest, which is about 93.7 kg/t toluene feed, and energy consumption for the separation section is reduced by 26.0%.

关 键 词：甲苯 甲醇 甲基化 二甲苯 分馏系统 节能优化 

分 类 号：TQ241.13[化学工程—有机化工]