GB845679A - Naphtha reforming process - Google Patents

Abstract

A naphtha is upgraded by separating by distillation into two fractions cutting at about 200 DEG F., treating the lower boiling fraction with a molecular sieve of the 5 type to remove normal paraffins, recombining the treated lower boiling fraction with the higher boiling fraction and reforming the recombined feed. The light naphtha is preferably treated with the molecular sieve in the vapour phase at 175-350 DEG F., flow. rates of 0.1-5 vol./vol./hr. and pressures of atmospheric to several hundred pounds per square inch. The sieve may be desorbed as required by using as stripping gas an olefine such as propylene or cracked refinery gas containing propylene heated to 200-300 DEG F. Reforming may be carried out over a molybdena-alumina catalyst, containing 10% molybdena and 2-5% silica, at 850-975 DEG F. and 50-500 p.s.i.g. using space velocities of 0,1-0,5 Wt/Wt/hr. and a recycle gas rate of 2,000-8,000 cubic feet per barrel of feed. Alternatively a platinum group metal-alumina catalyst, e.g. containing 0,01-1% platinum or 0,1-2% palladium preferably on eta-alumina having a surface area of 150-220 square metres per gram, may be used. Conditions in this case are 850-975 DEG F., 200-700 p.s.i.g., 0,5-4 Wt./Wt./hr. with 1,000-6,000 cubic feet of recycle gas per barrel. The catalyst may be regenerated by oxygen followed by chlorine treatment. The reforming may be carried out to give a product of Research octane number clear of 90-100.