Reclaiming ε-caprolactam from nylon 6 carpet

Claim 2

A process for the recovery of ε-caprolactam from nylon 6 carpet, comprising: a) providing a carpet made from nylon 6 fibers and having a non-nylon 6 backing containing one or more non-nylon 6 materials of polypropylene, jute, latex and fillers to a mechanical separator to prepare scrap containing both nylon 6 and non-nylon 6 backing materials, and a first waste portion; b) feeding the scrap from the separator to a depolymerizing reactor where the scrap is subjected to a depolymerization catalyst, temperatures of at least the melting point of nylon 6 and superheated steam to produce an ε-caprolactam containing distillate and a second waste portion; c) separating ε-caprolactam in the distillate from other volatiles therein; and d) purifying the ε-caprolactam obtained after separating so that the ε-caprolactam is of sufficient purity for reuse as a starting material for nylon 6 intended for use in carpet fiber.

Claim 3

The process of claim 1 further comprising e) routing the first and second waste portions to a power generating means as fuel for power production.

Claim 4

The process of claim 1 wherein said separating is by fractional distillation to obtain an aqueous fraction and a non-aqueous fraction.

Claim 5

The process of claim 3 further comprising h) sending the non-aqueous fraction to a power generating means.

Claim 6

The process of claim 1 wherein said purifying is by oxidizing the aqueous fraction, concentrating the oxidized aqueous fraction and distilling the concentrated oxidized aqueous fraction.

Claim 7

The process of claim 1 wherein said feeding is carried out continuously.

Claim 8

A process for recovering ε-caprolactam from nylon 6 carpet comprising: a) providing a carpet made from nylon 6 fibers and having a backing containing one or more non-nylon 6 materials of polypropylene, jute, latex and fillers to a mechanical separator to prepare scrap containing both nylon 6 and non-nylon 6 backing materials, and a first waste portion; b) feeding the scrap from the separator to a depolymerizing reactor where the scrap is subjected to a depolymerization catalyst, temperatures of at least the melting point of nylon 6 and superheated steam to produce an ε-caprolactam containing distillate and a second waste portion; c) separating ε-caprolactam in the distillate from other volatiles therein; and d) purifying the ε-caprolactam obtained after separating so that the purified ε-caprolactam is suitable for use as a starting material for nylon 6 carpet fiber; e) routing the first and second waste portions to a power generating means as fuel for power production; and f) sending the non-aqueous volatiles to the power generating means.

Claim 9

A process for recovering ε-caprolactam from nylon 6 carpet comprising: a) providing a carpet made from nylon 6 fibers and having a backing containing one or more non-nylon 6 materials of polypropylene, jute, latex and fillers to a mechanical separator to prepare scrap containing both nylon 6 and non-nylon 6 backing materials, and a first waste portion; b) feeding the scrap from the separator to a depolymerizing reactor where the scrap is subjected to a depolymerization catalyst, temperatures of at least the melting point of nylon 6 and superheated steam to produce an ε-caprolactam containing distillate and a second waste portion; c) separating ε-caprolactam in the distillate from other volatiles therein; and d) purifying the ε-caprolactam obtained after separating so that the purified ε-caprolactam is suitable for use as a starting material for nylon 6 carpet fiber; e) routing the first and second waste portions to a power generating means as fuel for power production; and f) sending the non-aqueous volatiles to the power generating means.

Claim 10

A process for reclaiming ε-caprolactam from nylon 6 carpet comprising: a) providing a carpet tufted with nylon 6 and having a backing containing latex for recycling; b) feeding the carpet to a depolymerization reactor; c) subjecting the carpet in the depolymerization reactor to a depolymerization catalyst present at about 1% to about 10% of the carpet weight at a temperature of about 230° C. and 325° C. to produce volatile monomers and a first waste portion; d) separating the volatile monomers from the first waste portion; and e) fractionating the volatile monomers to yield ε-caprolactam and a second waste portion.

Claim 11

The process of claim 8 further comprising using the first and second waste portions as feed for a power generating means.