歧化装置与芳烃装置二甲苯塔分离热耦合工艺

Thermal coupled process for separation of xylene tower in disproportionation unit and aromatic hydrocarbon unit

针对歧化装置和芳烃装置的C_(8)和C_(9)物料被重复冷凝与加热,以及设备数量多、投资大、占地多、开工程序复杂等缺点,中海石油宁波大榭石化有限公司将歧化装置的重芳烃塔与芳烃装置的二甲苯塔合并为1个新二甲苯塔,开发出满足C_(8)芳烃深度分离和C_(9)芳烃烷基转移的低成本分离热耦合精馏技术。结果表明:通过Petro-SIM软件模拟,该二甲苯塔分离热耦合工艺获得的C_(8)芳烃产品中甲苯质量分数小于0.98%,C≥9重芳烃质量分数小于2.51%,获得的C_(9)芳烃产品中C_(8)芳烃质量分数小于0.21%,C≥10重组分质量分数小于0.07%;与传统工艺相比,热耦合工艺装置建设投资约减少2700万元,节省占地6666.7 m^(2),减少二氧化碳排放9600 t/a。

In response to the drawbacks of repeated condensing and heating of C_(8)and C_(9)feedstocks in the disproportionation unit and aromatics units,as well as the large number of equipment,high investment,large land occupation,and complex start-up procedures,a low cost separation thermal coupled distillation technology that met the deep separation of C_(8)aromatics and alkyl transfer of C_(9)aromatics was developed by Ningbo Daxie Petrochemical Co Ltd of CNOOC.The characteristics of the distillation technology was that merged the heavy aromatics tower of the disproportionation unit and the xylene tower of the aromatics unit into a new xylene tower.The results showed that through the simulation of Petro-SIM software,the mass fraction of toluene in the C_(8)aromatic hydrocarbon product obtained by the thermal coupled process of the xylene tower separation was less than 0.98%,the mass fraction of C≥9 heavy aromatic hydrocarbons was less than 2.51%,and the mass fraction of C_(8)aromatic hydrocarbons in the C_(9)aromatic hydrocarbon product obtained was less than 0.21%,and the mass fraction of C≥10 heavy aromatic hydrocarbons was less than 0.07%.Compared with traditional processes,the construction investment of the thermal coupled process unit was reduced by about 27 million Yuan,saving 6666.7 m^(2)of land and reducing carbon dioxide emissions by 9600 t/a.