GB989301A - Improvements in or relating to the hydrogenation of unsaturated hydrocarbons - Google Patents

Abstract

The content of dienes is reduced in a mixture containing also hydrogen and carbon monoxide by passing the mixture in vapour phase over a supported nickel catalyst which, in operation, is partially sulphided but still contains a major proportion of nickel in elemental form, to cause hydrogenation of the dienes. The reaction temperature lies in the range 150 DEG to 400 DEG C., and the activated catalyst contains 2 to 20% by weight (of catalyst and support) elemental nickel. The catalyst support is preferably sepiolite, but alumina, kieselguhr, chalk and silica gel are mentioned. If a feedstock low in hydrogen is employed, it should be blended with a hydrogen-containing gas, and the mixture may contain small proportions of sulphur-containing compounds, preferably not less than 0.001 mol. %, and if no such compounds are present, extraneous sulphur compounds, diluted or not, are passed over the catalyst, e.g. as described in Specification 972,245 to sulphide a minor proportion of the nickel and improve the selectivity of the catalyst. Feedstocks mentioned are coal gas, town gas, producer gas, water gas, and as hydrogen-containing gas, various tail gases, e.g. one containing 70 mol. % hydrogen and 30 mol. % methane may be used. Inert constituents may be present. Four examples are described. Specification 476,684 also is referred to.