GB992264A - Hydrocracking process - Google Patents

Abstract

Hydrocarbon distillates containing 10-1000 p.p.m. of total nitrogen and boiling in the range 320-1050 DEG F. are hydrocracked using a catalyst which has been preferentially treated with ammonia to the exclusion of fouling by organic nitrogen compounds and using the treated catalyst in a continuous run of at least 750 hours in the presence of at least 1500 SCF hydrogen per barrel at 320-900 DEG F., 500-3,000 p.s.i.g. and 0.2-15 vol/vol/hour while continuosly raising the temperature to maintain a conversion of at least 20% per pass of product boiling below the initial boiling point of the feed and to maintain ammonia absorbed on the treated catalyst in equilibrium with ammonia produced from organic nitrogen compounds. The ammonia treatment may be effected prior to use but preferably is effected by contact with the feed hydrocarbon for not less than 100 hours at below 775 DEG F. while increasing the temperature; when the catalyst is fully ammonia treated there is an abrupt levelling off in the necessary rate of increase of temperature. The catalyst contains a hydrogenating-dehydrogenating component on an acidic, active cracking support, e.g. nickel sulphide and/or cobalt sulphide or silica-alumina, activated alumina, alumina-BF3 or a fluorided support.