Patent ID: 6429346
Filing Date: 2002-08-06
Classification: C07C,Y02P

Abstract:
A simultaneous process for simulated moving-bed dismutation of a feedstock comprising primarily toluene and separation of toluene, benzene and xylenes in the presence of a desorbent consisting essentially of hydrogen in at least one adsorber-reactor containing a plurality of beds of a solid and comprising at least three zones, whereina) a vapor-phase or supercritical feedstock is introduced at the inlet of a reaction and adsorption zone (zone III), and at the outlet of said zone, a raffmate enriched in benzene and desorbent is recovered, b) the resultant desorbent is introduced at the inlet of a desorption zone (zone I), and an effluent is recovered at the outlet of said zone from which a portion in the form of an extract enriched in xylenes and desorbent is drawn off, c) another portion of the effluent of zone I is introduced at the inlet of a reaction and desorption zone (zone II), and an effluent that is sent to the inlet of reaction and adsorption zone III is recovered at the outlet of said zone; wherein each of the zones comprises at least one bed that contains an adsorbent adapted to separate benzene, toluene and xylenes and a catalyst adapted to dismutate the toluene into benzene and xylenes, the adsorbent and the catalyst being in solid form.