Distillation: processes – separatory – Adding material to distilland except water or steam per se – Organic compound
Patent
1995-06-15
1997-10-21
Manoharan, Virginia
Distillation: processes, separatory
Adding material to distilland except water or steam per se
Organic compound
203 74, 203 75, 203 77, 203 78, 203 80, 568750, 568753, 568869, B01D 340, C07C 3780
Patent
active
056792239
ABSTRACT:
An extractive distillation process using a high boiling polyol such as glycerol is employed for separating high purity catechol, 3-methylcatechol and 4-methylcatechol from a high boiling, pitch-like dihydric phenol fraction. Fractional distillation first separates an impure overhead mixture of the catechol and 3-methylcatechol and an impure 4-methylcatechol bottoms. The impure overhead is extractively distilled to remove impurities and then extractively distilled again to separate the catechol and 3-methylcatechol. This produces a pure overhead of 3-methylcatechol and a bottoms of catechol and polyol which is distilled to recover the catechol and recycle the polyol. The impure 4-methylcatechol is distilled to remove residual material and then extractively distilled to remove impurities. The resulting mixture of 4-methylcatechol and polyol is distilled to recover the pure 4-methylcatechol and to recycle the polyol.
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Baker Gene G.
Duncan David H.
Kuhn Alfred K.
Maas Dana J.
Mohl Kevin M.
Dakota Gasification Company
Manoharan Virginia
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