RESEARCH ON DESULFURIZATION OF STRAIGHT-RUN DIESEL BY LIQUID-LIQUID CATALYTIC OXIDATION

Aiming at the technical and economical problems in diesel hydrodesulfurization technique which include high equipment investment and operation cost and problems in hydro peroxide oxidation desulfurization method such as expensive oxidant, low diesel yield and sulfur containing sewage emission, a new catalytic oxidation desulfurization method of straight-run diesel has been developed. At atmospheric pressure and low temperature, the straight-run diesel is catalyzed by a liquid catalyst TS-2 and oxidized by air, and then the oxidized diesel is extracted by a composite extracting solvent EA-5 and adsorbed by clay to remove the sulfide. Results have shown that under optimal conditions, i.e. 60℃, 0.1MPa, 5min and volume ratio of catalyst/diesel is 0.1, the total sulfur content of diesel can be reduced from 1658μg/g to 133μg/g, the yield of diesel can reach 97.5% and the sulfur content of refined diesel can meet the second classification standard of “World fuel specification”. Compared with other existing diesel desulfurization methods, the advantages of the method are low investment and operation cost, moderate operating conditions and no waste emission.