Catalytic reforming at low pressures and hydrogen rates - using platinum catalyst based on silicalite with small crystallite size

摘要

Reforming of hydrocarbon feeds contg. less than 1 ppm S is effected by contacting the feed with a catalyst at a temp. of 599-1058 deg.F, a pressure of less than 100 psig and an H2/feed molar ratio of 1 or less. Catalyst comprises Pt and an alkali(ne earth) metal (M) on silicalite. Silicalite has a crystallite content of at least 80% and SiO2/Al2O3 molar ratio of at least 1000. Size of at least 80 wt.% of the crystallites is less than 5 microns. Crystallite size is pref. less than 2 microns and silicalite is at least 95% crystalline. Catalyst contains 0.1-5 (esp. 0.3-2.5) wt.% Pt and sufficient M to neutralise at least 90% (esp. 100%) of the acid sites on the silicalite. Catalyst may also contain 0.1-1 wt.% of a promoter metal selected from Re, Sn, Au and Cr. Reforming is pref. effected at 644-1004 deg F. and 25-75 psig in the absence of added H2.