| 摘要 |
A simultaneous process for simulated moving-bed dismutation and separation of a toluene feedstock into benzene and xylenes in the presence of a hydrogen-rich desorbent in at least one adsorber-reactor (100) that contains beds of a solid and comprises at least three zones (23, 24, 25) is described. Vapor-phase or supercritical feedstock (1) is introduced at the inlet of a reaction and adsorption zone (25) (zone III), and a raffinate (15) that is high in benzene and desorbent is recovered at the outlet. Desorbent (5, 7) is introduced at the inlet of a desorption zone (23) (zone I), and an effluent from which is drawn off a portion (8) in the form of an extract that is high in xylenes and desorbent is recovered at the outlet. The other portion of the effluent of zone I is introduced at the inlet of a reaction and desorption zone (24) (zone II), and an effluent is recovered at the outlet that is sent back to the inlet of reaction and adsorption zone III. Each of the zones comprises at least one bed that contains an adsorbent that is adapted to separate benzene, toluene and xylenes, and a catalyst that is adapted to dismutate toluene into benzene and xylenes, whereby the adsorbent and the catalyst are in solid form. Application for the synthesis of terephthalic acid. FIG. 1 to be published.
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