Method of recovering caprolactam from mixed waste
AssigneeBASF SE
InventorsEdward A. Davis, Jack A. Dellinger
Life of this patent
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Abstract
A process for recovering caprolactam from waste containing both polycaprolactam and materials which are insoluble in acidic solvents for polycaprolactam includes agitating the waste in an acidic solvent capable of dissolving polycaprolactam without degrading the acid insoluble materials, separating the solution containing polycaprolactam from the acid insoluble materials, feeding the solution containing the polycaprolactam to a depolymerization reactor, without substantially precipitating the polycaprolactam and depolymerizing the polycaprolactam solution to obtain substantially pure caprolactam.
Claims12
A process for recovering caprolactam from waste containing both polycaprolactam and materials which are insoluble in acidic solvents for polycaprolactam comprising:
- (a) agitating the waste in an acidic solvent capable of dissolving polycaprolactam without degrading the acid insoluble materials and for a time sufficient to dissolve substantially all of the polycaprolactam;
- (b) separating the solution containing polycaprolactam from the acid insoluble materials;
- (c) without substantial precipitation, feeding the solution containing the polycaprolactam to a depolymerization reactor;
- and
- (d) depolymerizing the polycaprolactam solution to obtain caprolactam which is substantially free from ethylene glycol.
A process for recovering caprolactam from waste containing both polycaprolactam and polyethylene terephthalate comprising:
- (a) agitating the waste in an acidic solvent capable of dissolving polycaprolactam without degrading the polyethylene terephthalate and for a time sufficient to dissolve substantially all of the polycaprolactam;
- (b) separating the solution containing polycaprolactam from the acid insoluble materials;
- (c) without substantial precipitation, feeding the solution containing the polycaprolactam to a depolymerization reactor;
- and
- (d) depolymerizing the polycaprolactam solution to obtain caprolactam which is substantially free from ethylene glycol.
Dependencies are inferred from the claim text.