FCC柴油氧化萃取深度脱硫工艺研究

以氧气作氧化剂、甲酸作催化剂、N-甲基吡咯烷酮作萃取剂,采用催化氧化反应与溶剂萃取相结合的方法对催化裂化柴油进行了氧化萃取脱硫实验。考察了催化剂用量、催化氧化温度、反应时间、氧气压力及萃取剂的用量等对催化裂化柴油脱硫率的影响。结果表明,在反应温度为80℃、反应时间为90min、充氧压力为0.6MPa、催化剂与油体积比为10%的条件下,柴油经催化氧化脱硫后,硫含量可从1694.2μg/g降到190.8μg/g,脱硫率达到88.7%;在萃取剂油体积比为1.0和室温条件下,用N-甲基吡咯烷酮萃取3次,再经硅胶吸附后柴油硫含量为37.5μg/g,柴油收率为94%,达到欧Ⅳ排放标准小于50μg/g的要求。

STUDY ON THE DESULFURIZATION OF CATALYTIC CRACKED DIESEL BY OXIDATIVE EXTRACTION

This paper studied the combined desulfurization process of catalytic oxidation and solvent extraction for FCC diesel fractions by using hydrogen peroxide, formic acid and NMP as oxidation agent, catalyst and extraction agent, respectively. The influences of the amount of catalyst, reaction time, oxidation temperature, the pressure of oxygen and the amount of extraction agent on the sulfur removal rate were investigated. Test results showed that under the optimum conditions of a reaction temperature of 80 ℃, an oxidation time of 90 min, an oxygen pressure of 0.6 MPa and a catalyst to oil volume ratio of 0.1, the sulfur content of the treated diesel oil was reduced to 190.8 µg/g from the original 1 694.2 µg/g, the sulfur removal rate reached 88.7％. Then using a volume ratio of NMP to oil of 1.0, three times extraction at room temperature and further adsorption by silica gel, the yield of finished diesel fuel was 94%, and its sulfur content was 37.5 µg/g, which could well meet the requirement of European Emission Standard IV (less than 50 µg/g).