GB858420A - Improvements relating to the production of gas suitable for use as town gas - Google Patents

Abstract

858,420. Combustible gas. BRITISH PETROLEUM CO. Ltd., PORTER, H. T., RENSHAW, A. K., and WHITE, P. T. March 26, 1958 [March 29, 1957; Aug. 8, 1957], Nos. 10337/57 and 25024/57. Class 55 (2). A process for the production of town gas comprises contacting a petroleum fraction containing non-aromatic hydrocarbons and boiling within the gasoline or naphtha range with a dehydrogenating and dehydrocyclization catalyst under conditions such that a normally liquid product with a higher aromatic content than the feedstock and a hydrogen-rich gas are produced, the calorific value of the hydrogen-rich gas being reduced to a lower value, e.g. 500 B.Th.U., by dilution with a gas such as flue gas. The operating conditions may be a pressure of up to 50 p.s.i.g., a temperature of 450‹-580‹ C. and a space velocity of 0.1-1.0 v/v/hr. Preferably the catalyst is maintained as a fluidized or moving bed from which a portion is withdrawn for regeneration. Heat may be supplied by preheating the feedstock or recycled gas or by the regenerated catalyst. Suitable catalysts are those comprising metals of Group VI or Group VIII of the Periodic Table and is preferably chromium oxide supported on alumina optionally containing one or more promoters such as a rare earth or a mixture of rare earths, bismuth, boron, germanium or nickel, preferably in combination with an alkali metal, e.g. potassium. Other effective promoters include cobalt chromite, copper chromite, zinc titanate or iron chromite. Preferably a substantial proportion of the feedstock boils below 100‹ C. and may suitably be a light gasoline or a light relatively aromatic-free fraction of a catalytic reformate.