| 摘要 |
A method and apparatus is disclosed for the distillation of readily polymerizable vinyl aromatic compounds with polymerization inhibitors of low volatility, particularly a phenothiazine (PZ)-tertiarybutylcatechol (TBC) polymerization inhibitor combination. The method comprises introducing a feed of impure vinyl aromatic compound into a typical distillation train comprising a first fractionation column, a recycle column, and a finishing column; introducing as a separate stream into the upper portion of said recycle column and into said first fractionation column an effective amount of the PZ-TBC inhibitor in a volatile aromatic hydrocarbon diluent; and then distilling the vinyl aromatic compound in the presence of oxygen to recover an overhead product of high purity vinyl aromatic compound and a bottoms fraction.
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