PROCESS FOR PRODUCING HIGH-PURITY BISPHENOL A AND PRODUCTION APPARATUS

摘要

A process for producing bisphenol A which comprises: (A) a condensation reaction step in which phenol is condensed with acetone in the presence of an acid catalyst; (B) a concentration step in which the reaction mixture is concentrated; (C) a crystallization/solid-liquid separation step in which the concentrated reaction mixture is cooled to thereby separate a bisphenol A/phenol adduct from a mother liquor; (D) an isomerization step in which the mother liquor is wholly isomerized with an isomerization catalyst and the liquid resulting from the isomerization is circulated to the step (A) and/or step (B); (E) a recovery step in which the bisphenol A/phenol adduct is optionally recovered from part of the liquid resulting from the isomerization in the step (D); (F) an adduct decomposition step in which the phenol is removed from the adduct obtained in the step (C) to obtain a melt of bisphenol A; and (G) a granulation step in which the molten bisphenol A is granulated to produce prills as a product. The step (D) includes a free-acid removal step in which the free acid present in the mother liquor or liquid resulting from the isomerization is removed.