Patent ID: 8404085

Claim:
A process for the purification of a crude hydroquinone HQ 0 comprising hydroquinone and amounts of impurities, including both: (i) impurities having a lower evaporation temperature than that of hydroquinone, referred to as light impurities, including resorcinol; and (ii) impurities having a higher evaporation temperature than that of hydroquinone, referred to as heavy impurities, including pyrogallol, the process which consists essentially of the following stages: (A) a topping distillation, comprising introducing the crude hydroquinone HQ 0 into a topping distillation column and removing the resorcinol as distillation top product, optionally in conjunction with all or part of the light impurities, recovering a crude mixture M, comprising hydroquinone and the heavy impurities, at the topping column bottom, wherein a reflux ratio in the topping distillation column is between 300 to 2,000; and (B) a tailing distillation, comprising injecting the crude mixture M obtained in stage (A) into a tailing distillation column and removing the pyrogallol at the column bottom, optionally in conjunction with all or part of the heavy impurities, recovering hydroquinone in a purified form (HQ) at the tailing column top.