US5656757A — Monomer recovery from multi-component materials

Claim 1

Independent Claim 131 words

A process for recovering monomer from a multi-component polymeric waste material that includes at least one hydrolyzable polymeric component, comprising: (a) subjecting a mixture of water and the multi-component polymeric waste material to heat and pressure to form a liquid aqueous solution which includes as a major constituent a mixture of depolymerization products of the hydrolyzable polymeric component and a water insoluble portion which includes as a major constituent a mixture of materials other than the depolymerization products; (b) cooling the mixture resulting from step (a) at a temperature at which the water insoluble portion forms a plurality of finely divided solid particles; (c) separating the liquid aqueous solution and the finely divided solid particles; and (d) recovering a monomer that formed the hydrolyzable polymeric component from the liquid aqueous solution.

Claim 2

Dependent Claim 131 words

A process for recovering monomer from a multi-component polymeric waste material that includes at least one hydrolyzable polymeric component, comprising: (a) subjecting a mixture of water and the multi-component polymeric waste material to heat and pressure to form a liquid aqueous solution which includes as a major constituent a mixture of depolymerization products of the hydrolyzable polymeric component and a water insoluble portion which includes as a major constituent a mixture of materials other than the depolymerization products; (b) cooling the mixture resulting from step (a) at a temperature at which the water insoluble portion forms a plurality of finely divided solid particles; (c) separating the liquid aqueous solution and the finely divided solid particles; and (d) recovering a monomer that formed the hydrolyzable polymeric component from the liquid aqueous solution.

Claim 3

Dependent Claim 18 words

The process according the claim 1, wherein the liquid aqueous solution is cooled to below about 150° C.

Claim 4

Dependent Claim 27 words

The process according to claim 2, wherein the liquid aqueous solution is cooled to a temperature in the range of from about 70° to about 100° C.

Claim 5

Dependent Claim 31 words

The process according to claim 1, wherein step (d) includes removing water from the liquid aqueous solution, followed by separating the monomer from other depolymerization products of the hydrolyzable polymeric component.

Claim 6

Dependent Claim 33 words

The process according to claim 4, wherein at least about 75% of water, based on total weight of water in the liquid aqueous solution, is removed prior to the separation of the monomer.

Claim 7

Dependent Claim 21 words

The process according to claim 4, wherein water is removed by distillation or evaporation, prior to the separation of the monomer.

Claim 8

Dependent Claim 18 words

The process according to claim 4, wherein the monomer is separated from the other depolymerization products by distillation.

Claim 9

Dependent Claim 25 words

The process according to claim 7, wherein the distillation is conducted at a temperature in the range of from about 100° to about 150° C.

Claim 10

Dependent Claim 18 words

The process according to claim 8, wherein the distillation is conducted at a temperature below about 135° C.

Claim 11

Dependent Claim 32 words

The process according to claim 4, wherein separation of caprolactam from the other depolymerization products includes contacting a stream including the caprolactam and other depolymerization products with superheated steam, followed by condensation.

Claim 12

Dependent Claim 20 words

The process according to claim 1, wherein the hydrolyzable polymeric component comprises a polyamide and the monomer comprises a lactam.

Claim 13

Dependent Claim 33 words

The process according to claim 1, wherein the hydrolyzable polymeric component comprises a polyamide and the monomer comprises at least one of the group consisting of a dicarboxylic acid and an alkylene diamine.

Claim 14

Dependent Claim 113 words

A process for recovering caprolactam from carpet material that includes nylon 6 and non-nylon 6 components, comprising: (a) subjecting a mixture of water and the carpet material to heat and pressure to form a liquid aqueous solution which includes as a major constituent a mixture of nylon 6 depolymerization products and a water insoluble portion which includes as a major constituent a mixture of non-nylon 6 components; (b) cooling the mixture resulting from step (a) at a temperature at which the water insoluble portion forms a plurality of finely divided solid particles; (c) separating the liquid aqueous portion and the finely divided solid particles; and (d) recovering caprolactam from the liquid aqueous solution.

Claim 15

Dependent Claim 113 words

A process for recovering caprolactam from carpet material that includes nylon 6 and non-nylon 6 components, comprising: (a) subjecting a mixture of water and the carpet material to heat and pressure to form a liquid aqueous solution which includes as a major constituent a mixture of nylon 6 depolymerization products and a water insoluble portion which includes as a major constituent a mixture of non-nylon 6 components; (b) cooling the mixture resulting from step (a) at a temperature at which the water insoluble portion forms a plurality of finely divided solid particles; (c) separating the liquid aqueous portion and the finely divided solid particles; and (d) recovering caprolactam from the liquid aqueous solution.

Claim 16

Dependent Claim 18 words

The process according to claim 13, wherein the liquid aqueous solution is cooled to below about 150° C.

Claim 17

Dependent Claim 27 words

The process according to claim 14, wherein the liquid aqueous solution is cooled to a temperature in the range of from about 70° to about 100° C.

Claim 18

Dependent Claim 25 words

The process according to claim 13, wherein step (d) includes removing water from the liquid aqueous solution, followed by separating caprolactam from other depolymerization components.

Claim 19

Dependent Claim 37 words

The process according to claim 16, wherein at least about 75% of water, based on total weight of water in the liquid aqueous solution, is removed from the liquid aqueous solution prior to the separation of caprolactam.

Claim 20

Dependent Claim 21 words

The process according to claim 17, wherein the water is removed by distillation or evaporation, prior to the separation of caprolactam.

Claim 21

Dependent Claim 17 words

The process according to claim 16, wherein caprolactam is separated from the other depolymerization products by distillation.

Claim 22

Dependent Claim 25 words

The process according to claim 19, wherein the distillation is conducted at a temperature in the range of from about 100° to about 150° C.

Claim 23

Dependent Claim 18 words

The process according to claim 20, wherein the distillation is conducted at a temperature below about 135° C.

Claim 24

Dependent Claim 32 words

The process according to claim 16, wherein separation of caprolactam from the other depolymerization products includes contacting a stream including the caprolactam and other depolymerization products with superheated steam, followed by condensation.

Claim 25

Dependent Claim 38 words

The process according to claim 13, wherein the amount of water contacted with the carpet material is from about 0.5 to 7 parts of water per one part nylon 6 present in the carpet material, based on weight.

Claim 26

Dependent Claim 44 words

The process according to claim 13, wherein step (a) comprises subjecting the carpet and water mixture to sufficient heat and pressure to initiate depolymerization of nylon 6 and extract the resulting nylon 6 depolymerization products from the carpet material into the liquid aqueous portion.

Claim 27

Dependent Claim 17 words

The process according to claim 13, further comprising purifying crude caprolactam recovered from the liquid aqueous solution.

Claim 28

Dependent Claim 24 words

The process according to claim 13, further comprising recycling a residue from step (c) to mix with the carpet material feed in step (a).

Claim 29

Dependent Claim 31 words

A process according to claim 13, wherein the non-nylon 6 components include at least one material selected from the group consisting of jute, polypropylene, latex, calcium carbonate, clay and hydrated alumina.

Claim 30

Dependent Claim 131 words

A process for recovering caprolactam from a carpet material that includes nylon 6 and non-nylon 6 components, comprising: (a) introducing the carpet material and water into a reactor; (b) subjecting the resulting mixture to heat and pressure to form a liquid aqueous portion which includes a s a major constituent a mixture of nylon 6 depolymerization products and a water insoluble portion which includes as a major constituent a mixture of non-nylon 6 components; (c) cooling the mixture resulting from step (b) at a temperature at which the water insoluble portion forms a plurality of finely divided solid particles; and (d) separating the liquid aqueous solution and the finely divided solid particles; (e) removing at least 75% water from the liquid aqueous solution; and (f) separating caprolactam from other depolymerization products.

Claim 31

Dependent Claim 131 words

A process for recovering caprolactam from a carpet material that includes nylon 6 and non-nylon 6 components, comprising: (a) introducing the carpet material and water into a reactor; (b) subjecting the resulting mixture to heat and pressure to form a liquid aqueous portion which includes a s a major constituent a mixture of nylon 6 depolymerization products and a water insoluble portion which includes as a major constituent a mixture of non-nylon 6 components; (c) cooling the mixture resulting from step (b) at a temperature at which the water insoluble portion forms a plurality of finely divided solid particles; and (d) separating the liquid aqueous solution and the finely divided solid particles; (e) removing at least 75% water from the liquid aqueous solution; and (f) separating caprolactam from other depolymerization products.

Claim 32

Dependent Claim 16 words

The process according to claim 28, further comprising purifying the caprolactam separated from the other components.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-08-11	2001-02-10	2001-08-12	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-08-11	2005-02-10	2005-08-12	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-08-11	2009-02-10	2009-08-12	$7700.00	Window Closed / Lapsed

Monomer recovery from multi-component materials

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