METHOD OF SEPARATION OF PARAXYLENE INCLUDING ADSORPTION STAGE WITH INJECTION OF WATER AND CRYSTALLIZATION STAGE Russian patent published in 2002 - IPC

FIELD: separation of paraxylene from starting raw material containing mixture of aromatic C₈ isomers. SUBSTANCE: method includes adsorption and desorption stage of isomers of mixture in fluidized layer in at least one column containing zeolite with the use of desorbent. Adsorption and desorption are performed under conditions suitable for obtaining paraxylene enriched fraction and paraxylene depleted fraction. Method includes additionally one crystallization stage of paraxylene enriched fraction at obtaining pure paraxylene. According to invention water is introduced into starting raw material, desorbent and/or recirculating flow circulating between last and first layers of said column at such flow rate that average weight content of water in paraxylene enriched fraction and in paraxylene depleted fraction should range from 1 to 250 h/mln, mainly, from 3 to 120 h/mln. S/F ratio of flow rates of desorbent and starting raw material and desorption stage should be 6-2.5, mainly, 0.8-1.5 and preferably between 1 and 1.35. EFFECT: enhanced efficiency. 21 cl, 9 dwg, 1 tbl, 9 ex