加氢裂化轻石脑油博士试验问题及解决方案

中国石油独山子石化公司加氢裂化装置所生产的轻石脑油被作为车用汽油调合组分使用。装置开工初期，轻石脑油硫质量分数不大于3.5 μg/g，硫醇硫质量分数不大于3 μg/g，而博士试验不通过情况时有发生，针对这个问题对轻石脑油中不同活性硫化物进行定性与定量分析。结果表明：轻石脑油博士试验不通过的主因在于轻石脑油携带了痕量的硫化氢（质量分数不大于0.5 μg/g）协同硫醇所引起，只要脱除了硫化氢，博士试验就可以通过。基于此，提出了优化轻石脑油分馏系统的操作、轻石脑油分馏系统的蒸汽汽提改为重沸器汽提、对轻石脑油进行脱硫脱臭处理等工业上可行的解决方案。

PROBLEM OF DOCTOR TEST FOR HYDROCRAKING LIGHT NAPHTHA AND COUNTERMEASURES

The light naphtha from the hydrocracking unit of PetroChina Dushanzi Petrochemical Company is used as a blending component of vehicle gasoline. At the initial stage of plant start-up, the sulfur mass fraction of the light naphtha was no more than 3.5 μg/g, with the mercaptan sulfur content less than 3 μg/g, but sometimes the doctor test failed. To solve this problem, different active sulfides in light naphtha were analyzed qualitatively and quantitatively. The results showed that the main reason for the failure of the doctor test was the synergy of trace amounts of hydrogen sulfide (no more than 0.5 μg/g) with mercaptan in samples, as long as the hydrogen sulfide was removed, the doctor test could pass. Based on this, some feasible industrial solutions were put forward, such as optimizing the operation of light naphtha fractionation system, stripping by reboiled gas instead of steam stripping in light naphtha fractionator, and using the adsorptive desulfurization or sweetening process.