镇海炼化芳烃联合装置扩能增效改造实践

摘要

中国石油化工股份有限公司镇海炼化分公司450 kt/a对二甲苯(PX)联合装置在更换新型吸附剂的基础上,实施了吸附塔旁路流程改造、控制系统升级和分馏系统改造等一系列措施,对装置进行换剂扩能适应性改造.同时还进行了抽出液塔顶低温热利用和异构化冷高分改热高分的技术改造.装置改造后,PX产品在纯度为99.8％的情况下,收率可达97％左右,PX产能从520 kt/a提高到595 kt/a,有效地扩大了装置生产规模.装置抽出液塔顶低温热利用和异构化单元热高分工艺技术改造项目实施后,全年综合能耗从13.1 GJ/t下降至11.7 GJ/t,取得了较好的经济效益.%In the 450,000 TPY paraxylene (PX) unit of SINOPEC Zhenhai Refining & Chemical Co.,Ltd.,the capacity is expanded by the revamping through replacement of adsorbent,application of by-pass process for adsorption tower,upgrading of control system and revamping of fractionation system,etc.In addition,the unit is also revamped for utilization of low-temperature heat at overhead of extraction tower and cold high-pressure separation was revamped into hot high-pressure separation for isomerization system.After revamping of the unit,the purity of PX product is 99.8％,the yield is about 97％,the capacity of the unit is expanded from 520,000 TPY to 595,000 TPY.After implementation of effective utihzation of low-temperature heat at overhead of extraction tower and revamping of cold high-pressure separation into hot high-pressure separation for isomerization system,the annual energy consumption is reduced to 11.7 GJ/t from 13.1 GJ/t.The economic benefit is satisfactory.