GB646408A - Improvements in and relating to selective hydrogenation proceses - Google Patents

Abstract

The selective hydrogenation of acetylene in the presence of a lower olefine is effected by passing the mixture with the addition of hydrogen in the proportion of at least 1 mol. hydrogen to 1 mol. acetylene over a reduced nickel oxide catalyst containing sulphur (see Group III) at 125-350 DEG C. The reaction may be effected under pressure and in the presence of inert gaseous diluents. The Specification as open to inspection under Sect. 91 comprises also the selective hydrogenation of allylene or the butynes in presence of lower olefines, including propylene and the butylenes; or the hydrogenation of vinylacetylene in the presence of butadiene; or phenyl acetylene in the presence of styrene; or the hydrogenation of ethylenic linkages in the presence of aromatics; or the hydrogenation of a conjugate diolefine in the presence of the corresponding mono-olefine; employing the above catalyst. This subject-matter does not appear in the Specification as accepted.ALSO:A catalyst for selectively hydrogenating hydrocarbons (see Group IV (b)) is prepared by treating nickel oxide with a hydrogen-containing reducing gas at 200-600 DEG C., and then with a sulphiding agent, e.g. hydrogen sulphide, carbon bisulphide, lower alkyl mer-captans, a solution of sulphur in benzene or toluene or a sodium polysulphide solution, until the sulphur content of the resulting catalyst is from 2 to 50 equivalents of sulphur per 100 equivalents of nickel. In addition to nickel oxide the catalyst may also contain the following elements, either as such or in the form of compounds, e.g. oxides, A1, Cr, Mg, Mn, Si, Cu, Ag, Au, U, V, Ti, Th, Zr, Zn, Sn, Pb, Bi, Hg, Co, Fe, alkali; alkaline earth and rare earth metals, and platinum group metals. The catalysts may be formed into pellets with the aid of lubricants, e.g. stearin or graphite, and sintered. Alternatively they may be used in finely-divided form for the fluidized technique. They may also be supported on, e.g., carbon, clays and gels. The nickel oxide may be prepared by precipitating the carbonate, igniting to oxide, pilling and sintering. The Specification as open to inspection under Sect. 91 comprises also the incorporation of phosphorus, arsenic, antimony, selenium, tellurium and the halogens into the reduced nickel oxide instead of sulphur. This subject-matter does not appear in the Specification as accepted.