Catalytic Reforming of Naphtha and its Application to Aromatics Production (Part 3)

Abstract

Pyrolytic gasoline, by-product of ethylene manufacturing, contains much aromatics, from which benzene, toluene and xylene are recovered by two-stage hydrotreating and solvent-extraction. By hydrogenation, a small quantity of aromatics is lost through hydrogenation, and the hydrocarbons convertible to aromatics, if any, contained in the feed, can not be converted. On the other hand, by reforming of the gasoline, it is expected to obtain additional aromatics by dehydrogenation of naphthene.An experiment of reforming of pyrolytic gasoline was carried out, using a small reactor at 20∼30kg/cm2, 375∼510°C, the LHSV of 1.5hr-1 and H2 to hydrocarbon molar ratio of 6∼8. At the higher temperature (500°C) and the lower pressure (20kg/cm2), more aromatics were obtained than originally contained in the feed, and the bromine number as well as the sulfur content of the reformate were low enough for extraction.Reforming of pyrolytic gasoline is superior to conventional hydrotreating, with respect to higher aromatics yield and self sufficiency of hydrogen.