Hydrogenolysis of Sulphur Compounds Hydrodesulphurization

The most important technical application of sulphide catalysts is in the removal of sulphur compounds from fossil fuels by hydrodesulphurization (abbreviated hds) sulphur compounds are converted to hydrocarbons and H2S (which is removed by washing)  

The usual industrial catalyst consists of molybdenum (or occasionally tungsten) disulphide supported on y-alumina and promoted by cobalt (or more rarely nickel). An account was given in the earlier Report and more recent reviews of hds catalysts and reactions have been published. Delmon has published an excellent critique of work on the structure of Co-Mo catalysts. Technical processes have been reviewed,  

Objectives of current research are (a) determination of the structure of the catalyst and the active sites (ft) elucidation of reaction mechanisms and reaction networks (c) improved selectivity (desulphurization over hydrogenation) (d) longer catalyst lifetime (e) improved physical properties (mechanical strength, pore size distribution). 

Technical interest has concentrated on hydroprocessing heavy and residual oils and coal. The catalyst is required to be effective in hds and also in hydrocracking, hdn and hdo (Section 6), and demetallization. A particular problem in these applications is catalyst by carbon and metals deposition. 

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