METHOD OF DEPOLYMERIZING A POLYESTER IN A WASTE MATERIAL
A method of depolymerizing a polyester in a waste material is disclosed. The method comprises: supplying the waste material comprising the polyester to a depolymerization vessel; depolymerizing the polyester to form a depolymerized mixture comprising a regenerated diol, a regenerated diacid, and a catalyst; isolating the regenerated diacid and the catalyst from the regenerated diol to form a regenerated composition including the regenerated acid and the catalyst; and separating the regenerated composition from the regenerated diol. In addition, a regenerated composition formed from depolymerization of a waste material is disclosed wherein the regenerated composition comprises a regenerated diacid and a catalyst and wherein the catalyst is present in an amount of from 5 ppm to 300 ppm.
1 - 46 . (canceled)
47 . A method of depolymerizing a polyester in a waste material, the method comprising:
supplying the waste material comprising the polyester to a depolymerization vessel;
depolymerizing the polyester to form a depolymerized mixture comprising a regenerated diol, a regenerated diacid, and a catalyst;
isolating the regenerated diacid and the catalyst from the regenerated diol to form a regenerated composition including the regenerated acid and the catalyst; and
separating the regenerated composition from the regenerated diol.
48 . The method of claim 47 , wherein the waste material is a waste textile.
49 . The method of claim 47 , wherein the catalyst comprises antimony.
50 . The method of claim 47 , wherein the catalyst comprises an antimony trioxide, antimony glycolate, an antimony/metal composite, or a mixture thereof.
51 . The method of claim 47 , wherein the catalyst comprises an antimony acetate.
52 . The method of claim 47 , wherein the catalyst is present in the regenerated composition in an amount of from greater than 0 ppm to 300 ppm.
53 . The method of claim 47 , wherein the catalyst is present in the regenerated composition in an amount of from greater than 0 wt. % 0.05 wt. % based on the weight of the regenerated diacid.
54 . The method of claim 47 , wherein the regenerated diacid comprises an aromatic diacid.
55 . The method of claim 54 , wherein the aromatic diacid comprises a terephthalic acid.
56 . The method of claim 47 , wherein the regenerated diol comprises an aliphatic diol.
57 . The method of claim 56 , wherein the regenerated diol comprises ethylene glycol.
58 . The method of claim 47 , wherein the depolymerization is conducted at a temperature of from 100° C. to 220° C.
59 . The method of claim 47 , wherein the depolymerization is conducted in water.
60 . The method of claim 47 , wherein the depolymerization is conducted via hydrolysis.
61 . The method of claim 60 , wherein the hydrolysis is conducted in the presence of a strong base.
62 . The method of claim 47 , further comprising:
clarifying the depolymerized mixture.
63 . The method of claim 62 , further comprising:
decolorizing the depolymerized mixture.
64 . The method of claim 63 , wherein decolorization is conducted using a decolorizing agent comprising activated charcoal.
65 . The method of claim 47 , wherein the isolating step comprises precipitating the regenerated diacid and the catalyst.
66 . The method of claim 65 , wherein the precipitating step comprises adding a strong acid to the depolymerized mixture.
67 . The method of claim 65 , wherein the precipitating step is conducted at two intervals, each at a different pH.
68 . The method of claim 47 , wherein the waste material comprises a polyester and at least one other polymer.
69 . The method of claim 68 , wherein the at least one other polymer comprises cellulose or a polyamide.
70 . The method of claim 47 , wherein the polyester is depolymerized without the addition of a catalyst during the depolymerizing step.
71 . A regenerated composition formed from depolymerization of a waste material, the regenerated composition comprising a regenerated diacid and a catalyst, wherein the catalyst is present in an amount of from 5 ppm to 300 ppm.