Abstract: Taking the aromatics isomerization unit of a factory as research object, the differences between the cold and hot high pressure separation processes are briefly introduced. The purity of recycle hydrogen, equipment investment, energy consumption and operation cost of the two separation processes are compared based on the PROⅡ simulation results. Compared with cold high pressure separation process, although the purity of recycle hydrogen decreases, the increase of dissolved hydrogen will lead to a slight increase of make-up hydrogen. However, the heat-exchange process of hot high pressure separation process is more reasonable, and the steam consumption of deheptanizer reboiler reduces greatly with the increase of feed temperature of deheptanizerd. By adopting the hot high pressure separation process, the equipment investment can be reduced by 1.054 million yuan, the energy consumption can be reduced by 107.1 MJ/t, the annual operation cost can be saved by 12.97%, and the overall income of the unit can be increased. In general, hot high pressure separation process is suitable for aromatics isomerization unit.

Key words: aromatics isomerization unit, cold high pressure separation process, hot high pressure separation process, purity of recycle hydrogen, energy consumption

摘要： 以某厂芳烃异构化装置为研究对象,介绍芳烃异构化装置存在的冷、热两种高压分离(高分)工艺流程的区别,结合PROⅡ软件模拟计算结果,从循环氢纯度、设备投资、能耗和操作费用等方面对两种工艺进行综合分析。结果表明,相比冷高分工艺,尽管采用热高分工艺循环氢纯度降低、溶解氢量增加会造成补充氢量略有提高,但装置换热流程更为合理,脱庚烷塔进料温度升高,塔底重沸器蒸汽耗量大幅度降低。通过计算比较,采用热高分工艺,设备投资可减少105.4万元,装置能耗降低107.1 MJ/t,年操作费用节省12.97%,装置整体效益提高。综合考虑,芳烃异构化装置选用热高分工艺更有优势。

关键词: 芳烃异构化装置, 冷高分工艺, 热高分工艺, 循环氢纯度, 能耗