关键词: 催化裂化, 柴油, 脱硫, 催化氧化, 氧气

Abstract: 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).

Key words: catalytic cracking, diesel, desulfurization, catalytic oxidation, oxygen