| 摘要 |
The present invention relates to a process of separation and purification allowing purified hydroquinone to be obtained from crude mixtures essentially containing hydroquinone in combination with very small amounts of impurities including resorcinol and pyrogallol. The process of the invention, which involves starting from a crude hydroquinone containing said impurities, is characterized in that it comprises a topping distillation allowing the resorcinol to be removed as the distillation top product, and allowing a crude mixture essentially comprising hydroquinone and the heavy impurities to be recovered at the column bottom, said mixture then being subjected to a bottoming distillation which allows the pyrogallol to be removed at the column bottom and allows hydroquinone in a purified form to be recovered at the column top.
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