Distillation process for recovery of high purity phenol
AssigneeAllied-Signal Inc.
InventorsMichael S. O'Donnell, Lamberto Crescentini
Life of this patent
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Abstract
High purity phenol is obtained from cleavage of cumene hydroperoxide by treating the crude phenol product stream in a first treatment zone with an amine, a coarse distillation to obtain an overhead stream comprising phenol, alpha-methyl styrene, cumene, and impurities, and steam distillation of the overhead stream in combination with addition of an amine to the steam distillation column for a second amine treatment step.
Claims28
In a process for producing high purity phenol wherein alpha-methyl styrene (AMS) is produced as a by-product, the improvement comprising:
- recovering a crude phenol product stream which includes AMS produced as a by-product in an amount of at least 0.5 weight percent and no greater than 10 weight percent, based on weight of phenol, and further includes acetol, 2-phenyl-propionaldehyde (2PPA), methyl-benzofuran (MBF), mesityl oxide (MO), and carbonyl impurities;
- treating said crude phenol product stream in a first treatment zone with an amine to convert acetol and 2PPA to higher boiling components;
- distilling said treated phenol product stream to separate higher boiling components and an overhead stream comprising phenol, AMS, and impurities including MBF, MO, and carbonyl compounds;
- steam distilling said overhead stream in a steam distillation column with a water to phenol ratio of at least 0.2:1 and no greater than 1.2:1 to recover a light product comprising phenol, water, AMS, MBF and carbonyl compounds and a heavy product comprising phenol having a reduced quantity of MBF, AMS, and carbonyl compounds, relative to said overhead stream;
- said steam distillation step additionally comprising a second amine treatment step whereby an effective amount of an amine is added to the lower portion of said steam distillation column to convert MO and carbonyl impurities to heavy and light impurities;
- and distilling the heavy product from the steam distillation step to recover high purity phenol and a bottoms product containing heavies and unreacted amine.
In a process for producing phenol by oxidation of cumene to cumene hydroperoxide and cleavage of cumene hydroperoxide to phenol and acetone wherein alpha-methyl styrene (AMS) is produced as a by-product, the improvement comprising:
- recovering a crude phenol product stream which includes some unreacted cumene, AMS produced as a by-product in an amount of at least 0.5 weight percent and no greater than 10 weight percent, based on weight of phenol, and further includes acetol, 2-phenyl-propionaldehyde (2PPA), methyl-benzofuran (MBF), mesityl oxide (MO), and carbonyl impurities;
- treating said crude phenol product stream in a first treatment zone with an amine to convert acetol and 2PPA to higher boiling components;
- distilling said treated phenol product stream to separate higher boiling components and an overhead stream comprising phenol, AMS, cumene, and impurities including MBF, MO, and carbonyl compounds;
- steam distilling said overhead stream in a steam distillation column with a water to phenol ratio of at least 0.3:1 and no greater than 1.0:1 to recover a light product comprising phenol, water, cumene, AMS, MBF and carbonyl compounds and a heavy product comprising phenol having a reduced quantity of MBF, AMS, and carbonyl compounds, relative to said overhead stream;
- said steam distillation step additionally comprising an amine treatment step whereby an effective amount of an amine is added to the lower portion of said steam distillation column to convert MO and carbonyl impurities to heavy and light impurities;
- distilling the heavy product from the steam distillation step to recover high purity phenol and a bottoms product containing heavies and unreacted amine;
- and recycling said bottoms product containing heavies and unreacted amine to the first treatment zone, thereby providing said amine to said first treatment zone.
Dependencies are inferred from the claim text.