GB1285791A - Process for producing gasoline - Google Patents

Abstract

1285791 Cracking; hydrotreating UNIVERSAL OIL PRODUCTS CO 12 Jan 1970 1377/70 Heading C5E Gasoline is produced by:-(a) catalytically cracking a feed stock (1) by cocurrent contact with freshly regenerated fluid catalytic cracking catalyst in a dilute phase riser cracking zone 5 to form first reaction products and partially deactivated cracking catalyst; (b) separating a stream 11 of first reaction products from the partially deactivated catalyst; (c) passing the partially deactivated catalyst into a fluidized dense phase bed of partially deactivated catalyst; (d) catalytically cracking a hydrotreated cycle oil stream 27 by contact with the dense phase bed of partially deactivated catalyst to form second reaction products; (e) separating a stream 12 of second reaction products from the cracking catalyst; (f) commingling the streams 11 and 12; (g) recovering a gasoline 15, suitably boiling up to 350-450‹ F., from the commingled product 13; (h) recovering a cycle oil 17 having an average boiling point above that of the gasoline 15 and rich in aromatics, the major type of aromatics being J-12, from the commingled product 13; (i) catalytically hydrotreating the cycle oil 17 in the presence of hydrogen at 21 to retain a major portion of the aromatics but convert the types of aromatics such that the major type of aromatic is J-8; and (j) recovering the hydrotreated cycle oil from step (i) and returning a stream 27 of hydrotreated-cycle oil to step (d). The cycle oil can be recovered from the commingled product 13 as a cycle oil 17, suitably boiling up to 550-750‹ F., which is catalytically hydrotreated in step (i) and a heavy cycle oil 2 which is combined with the feed 1 to step (a). Suitable feeds 1 are atmospheric gas oil, vacuum gas oil, coker gas oil and mixtures of these; a refractory stock 35 can also be introduced into the hydrotreating zone 21. The cracking is carried out at 800-1050‹ F., up to 50 p.s.i.g. and a ratio in riser 5 of total feed to fresh feed of 1À1-2À0 to convert 30-80% of the feed to gasoline per pass. Suitable cracking catalysts are amorphous silica-alumina, silicamagnesia, silica-zirconia, acid-activated clay, faujasite or mordenite dispersed in a silica or alumina containing matrix. The hydrotreating is carried out at 500-850‹ F. and 400-2000 p.s.i.g. using a fixed bed of catalyst comprising a support of alumina, silica-zirconia, silicamagnesia, silica-alumina, faujasite or mordenite bearing W and/or Mo along with Ni or Co, platinum or palladium.