GB848232A - Improvements in or relating to hydrogenation - Google Patents

Abstract

Gasolines containing at least one diolefine are improved by destruction of gum-forming constituents by passing with hydrogen over a supported catalyst containing nickel which under the operating conditions is present in major proportions as the metal, the conditions being such that diolefines are converted to mono-olefines without appreciable conversion of mono-olefines to saturated hydrocarbons, the hydrogen consumption preferably being limited to such that the octane number of the product is not less than that of the feedstock by more than a small amount. The feedstock may boil in the range 15 DEG -200 DEG C. and preferably has a sulphur content of 0,005-0,04%; steam cracked gasolines are particularly suitable. The catalyst is preferably supported on silica-free alumina. The hydrogen employed need not be pure hydrogen but a gas containing 25-90 mol. per cent. hydrogen such as tail gas from reforming, steam cracking, catalytic cracking or dehydrogenation processes. Suitable conditions are 0-200 DEG C. and 0-1,000 p.s.i.g. at a space velocity of 1-5 vol./vol./hr. with a gas rate of 300-700 SCF/B. The octane number is preferably not reduced by more than 2,5.ALSO:Gasolines containing mono- and di-olefines are improved by destruction of gum-forming constituents by passing with hydrogen over a supported catalyst containing nickel which under the operating conditions is present in major proportions as the metal, the conditions being such that di-olefines are converted to mono-olefines without appreciable conversion of mono-olefines to saturated hydrocarbons, the hydrogen consumption preferably being limited to such that the octane number of the product is not less than that of the feedstock by more than a small amount. The feedstock may boil in the range 15-200 DEG C. and preferably has a sulphur content of 0.005-0.04%; steam cracked gasolines are particularly suitable. The catalyst is preferably supported on silica-free alumina. The hydrogen employed need not be pure hydrogen but a gas containing 25-90 mol. per cent hydrogen such as tail gas from reforming, steam cracking, catalytic cracking or dehydrogenation processes. Suitable conditions are 0-200 DEG C. and 0-1000 p.s.i.g. at a space velocity of 1-5 vol/vol/hr. with a gas rate of 300 - 700 SCF/B. The octane number is preferably not reduced by more than 2.5. Specification 660,155 is referred to.