Method for separating carbazole from coal tar
By using an o-xylene-m-xylene composite solvent system and an optimized crystallization and washing process, the problem of low carbazole yield in the prior art was solved, and the efficient preparation of high-purity carbazole was achieved, significantly improving the carbazole yield.
Patent Information
- Application Number
- CN202511283697.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-09
- Publication Date
- 2025-11-18
AI Technical Summary
The yield of purified carbazole prepared by solvent crystallization-distillation in the existing technology is low, which is difficult to meet the market demand for high-purity carbazole.
Using an o-xylene-m-xylene composite solvent system as the solvent, the yield of carbazole was improved by optimizing the crystallization temperature and washing steps through multiple crystallization and washing processes.
The yield of carbazole was significantly improved. When the volume ratio of o-xylene to m-xylene was 1:2, the yield of carbazole reached 63.28%, which was 8.25% higher than that of xylene solvent alone, and the overall improvement rate was 15.00%. It was further improved to 66.76% by recovering the washing liquid phase, with an improvement rate of 21.38%.