Patent ID: 6398947
Filing Date: 2002-06-04
Classification: C10G

Abstract:
A multistage integrated process for upgrading a petroleum naphtha comprising the steps of(a) introducing the naphtha to a catalytic reforming stage comprising a plurality of operatively connected catalyst zones including a first catalyst zone and a last catalyst zone, the last catalyst zone being maintained under reforming conditions of temperature ranging from at least 800Â° F. (427Â° C.) to 2192Â° F. (1200Â° C.), pressure of 0 psig (103 kPa) to 1000 psig (6998 kPa), a WHSV of from 0 to 50/hr and a hydrogen to hydrocarbon mole ratio of from 0 to 10, in order to provide an intermediate product comprising aromatics and paraffins; (b) transferring without interstage separation at least a portion of the intermediate product of the last catalyst zone, together with a toluene cofeed, to a synthesis zone for benzene and xylenes, the synthesis zone comprising at least one catalyst, wherein the synthesis zone is operatively connected to the last catalyst zone of the reforming stage of step (a), the synthesis zone being maintained under conditions of temperature ranging from at least 572Â° F. (300Â° C.) to 2192Â° F. (1200Â° C.), pressure of 0 psig (103 kPa) to 1000 (6998 kPa), a WHSV of from 0 to 50/hr and a hydrogen to hydrocarbon mole ratio of from 0 to 10, the catalyst of the synthesis zone comprising a molecular sieve having an alpha value greater than 100, and a sorption time of greater than 50 minutes based on its capacity to sorb 30% of the equilibrium capacity of ortho xylene at 120Â° C. and a xylene pressure of 4.5+/âˆ’0.8 mm of mercury to provide a hydrocarbon product of higher benzene and xylene content than the intermediate product of the last catalyst zone of the reforming stage.