Continuous Hydrogenation of Steam Cracked Gasoline

Abstract

Studies on continuous hydrogenation of steam cracked gasoline were made, using nickel subsulfide catalyst.The catalyst used was prepared by sulfiding nickel with hydrogen containing hydrogen sulfide in small concentration e.g. 1% by volume, at a low temperature e.g. 200°C, and treating this sulfided nickel with hydrogen or a mixture of hydrogen and hydrocarbon oil at a temperature from 200° to 300°C. Principal constituent of this catalyst was found to be nickel subsulfide, Ni3S2, by X-ray diffraction.The catalyst is active for the hydrogenation of diolefins in steam cracked gasoline but is inactive for the hydrogenation of aromatic nucleus. Such a selectivity has not been found with metallic nickel catalyst.Hydrogenation conditions used were such as follows: temperature 100° to 170°C; pressure 10 to 50kg/cm2, gauge; liquid space velocity 1.0 to 6.2.Since no high polymerization and cracking reactions were observed and catalytic activity and selectivity were constant during the 3.5 months of the catalyst life test, it is expected that the life could be extended further.