| 摘要 |
Processes have been developed to obtain recycle ionic liquid streams which are active for oxidation of alkyl aromatic compounds, and which reduce the amount of 4-CBA in the solid oxidation products. The process can reduce the makeup amount of ionic liquid, carboxylic acid, catalyst, bromine source, and ammonia source. |
| 主权项 |
1. A process for oxidizing an alkyl aromatic compound comprising:
contacting the alkyl aromatic compound, a first solvent comprising an ionic liquid and a carboxylic acid, a bromine source, a catalyst, and an oxidizing agent in a reaction zone under oxidizing conditions to produce an oxidation product comprising aromatic carboxylic acid, and at least one of dissolved unoxidized alkyl aromatic compound or dissolved partially oxidized alkyl aromatic compound, at least 25% of the aromatic carboxylic acid remaining in solution; crystallizing at least a portion of the aromatic carboxylic acid in a crystallization zone to produce a solid product comprising a crystallized aromatic carboxylic acid and a mother liquor liquid comprising the first solvent, and the at least one of unoxidized alkyl aromatic compound or partially oxidized alkyl aromatic compound and optionally aromatic carboxylic acid in solution; separating the solid product from the mother liquor liquid; separating the mother liquor liquid into a volatile portion comprising one or more of the carboxylic acid, the bromine source, and water, and a nonvolatile portion comprising the ionic liquid, the catalyst, and the at least one of dissovled unoxidized alkyl aromatic compound or dissolved partially oxidized alkyl aromatic compound; optionally introducing one or more of additional ionic liquid, additional carboxylic acid, additional bromine source, or additional ammonia or ammonium compound into the nonvolatile portion; and recycling at least a portion of the nonvolatile portion to the first reaction zone. |
