Continuous distillation of phthalic anhydride with vapor side stream recovery
Abstract
Abstract A PROCESS FOR CONTINUOUS DISTILLATION PURIFICATION OF PHTHALIC ANHYDRIDE WITHIN PREHEATED PHTHALIC ANHYDRIDE IS FED TO THE MIDDLE SECTION OF A DISTILLATION COLUMN OPERATED UNDER A SUMP PRESSURE OF ABOUT 500-800 MM. HG, FORERUNNINGS CONTAINING MORE VOLATILE COMPONENTS ARE CONTINUOUSLY SEPARATED AT THE HEAD OF THE COLUMN, A RESIDUE CONTAINING HIGHER-BOILING CONTAMINATES IS WITHDRAWN FROM THE SUMP, AND A SIDESTREAM OF PURIFIED PHTHALIC ANHYDRIDE HAVING A PURITY OF 99.1 TO 99.95% BY WEIGHT IS REMOCED IN THE VAPOR PHASE FROM THE LOWER PART OF THE COLUMN STRIPPING SECTION. FURTHER PURIFICATION MAY BE OBTAINED BY PASSING THE PURIFIED SIDESTREAM PRODUCT INTO A SMALL VACUUM DISTILLATION COLUMN.
Inventors
- 👤 H Gehrken
- 👤 G Helms
- 👤 G Keunecke
- 👤 H Krimphove
Bibliographic Details
Claims Analysis
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