| 摘要 |
<p>Light impurities boiling below phenol are removed by extractive distillation using auxiliary extraction liquids boiling above phenol. Most of the light impurities are eliminated as first runnings. The still product ie. phenol + auxiliary liquids + remaining impurities, is fractionate continuously. High-purity phenol is liquid side-product (outlet between 5th and 15th plate from column head). Auxiliary liquid from the still is recycled, and the mixture of phenol and impurities from column head is partly refluxed and partly returned for extractive distillation.</p> |
