煤制氢低温甲醇洗装置改造方案研究

Research on upgrading scheme for rectisol unit in a coal to hydrogen plant

某石化厂将煤制氢原料中掺混的低硫石油焦换成了高硫石油焦,希望以此进一步降低原料成本,但经过操作发现进入低温甲醇洗装置的原料气中H2S大量增加,远超原装置设计值,因此需要对这部分的工艺流程进行改进。首先采用RPS软件对与原设计相似的工艺流程进行了模拟计算,确认可用于高硫工况;接下来新增加了1套未变换气洗涤系统以净化新增未变换气,并再次对高硫工况进行了模拟计算;最后提出了2种方案,建议优选方案2进行改造。

A petrochemical plant replaces low-sulfur petroleum coke blended in the coal-to-hydrogen feedstock with high-sulfur petroleum coke,hoping to further reduce the feedstock cost.However,after operation,it is found that the H_2S content in the feed gas entering the rectisol unit increases significantly,far exceeding the original plant design value.Therefore,the process in this section needs to be improved.The original process is firstly simulated by using RPS software to confirm that it can be used for simulation of the high sulfur conditions.Next,a new unconverted gas scrubber system is added to clean the additional unconverted gas.Simulation is also performed for high sulfur conditions.Finally,two upgrading schemes are proposed,and scheme 2 is recommended as the preferred option for actual modification.