Hydrocarbon treating process involves: (a) combining a hydrogen feed stream, a recycle stream and a hydrocarbon feed stream to form a combined feed stream comprising propane, butane, hydrogen and methane, passing this stream through a reaction zone containing a bed of catalyst operating at conditions effective to simultaneously promote diene hydrogenation, the reaction of mercaptans and olefins present to form thioethers and the isomerisation of n-olefins, to form a reaction zone effluent stream comprising hydrogen, ethane, propane, butane and thioethers, (b) recovering heat from a first portion of the effluent by indirect heat exchange against fluid removed from the stripping section of a unitary fractionation column, and then passing the first portion of the effluent into the reaction zone as the recycle stream, (c) passing a second portion of the effluent into a stripping section of the fractionation zone which comprises an upper stripping section and a lower rerun section operated at differing reflux ratios, with the reflux ratio of the stripping section being greater than that of the rerun section, (d) passing a liquid phase process stream comprising butane and thioethers from the bottom of the stripping section into the rerun section, (e) recovering a net overhead product stream comprising hydrogen and ethane from the stripping section and withdrawing the net overhead product stream from the process, (f) recovering a liquid phase butane rich net product stream which is free of thioethers by at least partially condensing a vapour phase process stream removed at the top of the rerun section and withdrawing the net product stream from the process and (g) recovering a net bottoms stream comprising thioethers from the bottom of the rerun section.    USE -   For thioetherification and selective hydrogenation of light hydrocarbons especially to gasoline products.    ADVANTAGE -   Provides increased simultaneous conversion of mercaptans to higher boiling compounds, isomerisation of light monoolefins and selective hydrogenation of diolefins. Process costs are reduced.