Method for the recovery of caprolactam
Abstract
Abstract A process comprising the steps of: A. CONTACTING AT A TEMPERATURE RANGING FROM ABOUT 40* C. to about 90* C. a rearrangement mass comprising Epsilon caprolactam and sulfuric acid with the following reactants: (I) SUBSTANTIALLY WATER-FREE AMMONIUM SULFATE IN AN AMOUNT RANGING FROM ABOUT 0.9 TO ABOUT 1.1 MOLES PER MOLE OF SULFURIC ACID PRESENT IN SAID REARRANGEMENT MASS, AND (II) AN AQUEOUS AMMONIUM BISULFATE SOLUTION SATURATED AT A TEMPERATURE WITHIN THE RANGE OF 20* TO 55* C., the amount of said aqueous solution being such as to dissolve at the contacting temperature the ammonium bisulfate formed by the reaction of the sulfuric acid component of the rearrangement mass with said ammonium sulfate, to thereby afford an Epsilon -caprolactam phase and an aqueous ammonium bisulfate phase; B. SEPARATING SAID Epsilon -CAPROLACTAM PHASE; C. COOLING SAID AQUEOUS AMMONIUM BISULFATE PHASE TO A TEMPERATURE WITHIN THE RANGE OF 20* TO 55* C. to thereby afford crystalline ammonium bisulfate and a saturated aqueous ammonium bisulfate solution; D. RECOVERING AND RECYCLING SAID SATURATED AQUEOUS SOLUTION TO STEP A).
Inventors
- 👤 Leland J Beckham
Bibliographic Details
Claims Analysis
Total Claims: 4References Cited (Backward Citations)
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