Patent ID: 6844472
Filing Date: 2005-01-18
Classification: C07C

Abstract:
1. A process for separation and purification of a crude mixture comprising hydroquinone and resorcinol, in which process the crude mixture is first subjected to a series of distillation stages comprising: (i) subjecting the crude mixture to a distillation stage (II) designed to produce, as a distillation top product, a resorcinol-rich fraction comprising resorcinol, essentially, and hydroquinone; (ii) subjecting a distillation bottom product obtained by step (i) to a distillation stage (III) designed to produce, as a distillation top product, a hydroquinone-rich fraction comprising hydroquinone, essentially, and resorcinol; and then subjecting the hydroquinone-rich fraction and/or the resorcinol-rich fraction to a refining stage (IV or V) in order to extract the hydroquinone and/or the resorcinol, respectively, wherein the refining stage comprises successive cooling/crystallization, draining of a eutectic, reheating and draining a liquid fraction, and then melting-recovering a crystallized fraction.