低硫原料对加氢裂化装置运行的影响及对策

Effect of low-sulfur vacuum gas oil on hydrocracking process and its counter measures

介绍了中国石油长庆石化公司120万t/a加氢裂化装置加工自产减压蜡油(长庆VGO,含硫质量分数小于0.1%)的实际运行状况,分析了低硫原料对加氢裂化反应所产生的影响,并与注硫后的运行情况进行了对比,提出加工低硫原料的应对措施。结果表明,长庆VGO硫含量低,导致循环氢中的H2S含量亦较低,进而使催化剂硫化度降低,活性下降;通过注入预硫化剂,可使循环氢中H2S含量增大,NH3含量降低,反应温升提高,催化活性增大;加工低硫原油时,可降低反应出口注水量以提高循环氢中的H2S含量,并采取适宜的补硫措施,如注入预硫化剂、掺炼高硫原料、回收富氢气体中的H2S等。

Selfproduced vacuum gas oil （ VGO, mass fraction of sulfur less than 0. 1% ） was pro- cessed in a 1.20 Mt/a hydrocracking unit of Chan- gqing Petrochemical Company. The effect of the low ulfur feedstock on hydrocracking reaction was investigated, the comparison with sulfur- adding process was conducted, and the countermeasures for processing lowsulfur feedstock were proposed. The results showed that the low content of sulfur in selfproduced VGO resulted in the low content of H2S in recycle hydrogen, thus the decrease of both sulfidity and activity of catalysts. Adding presulfurizing agentcould increase H2S content in recycle hydrogen, de- crease NH3, raise reaction temperature and improve activity of the catalysts. For the processing of lowsulfur feedstock, reducing the amount of adding water at reactor outlet could increase the H2S content in recycle hydrogen, and the appropriate sulfur supplement method could also be selected,such as adding presulfurizing agent,mixing highsulfur feedstock and re- covering H2S from rich hydrogen gas et al.