METHOD OF AGING REGENERATED DIACID CRYSTALS
A method of obtaining a purified regenerated diacid from a depolymerization of a polyester in a waste material wherein the depolymerization provides a depolymerized mixture comprising a regenerated diol, a regenerated diacid, and a catalyst is disclosed. The method comprises: separating a regenerated composition including the regenerated acid and the catalyst from the regenerated diol; providing the regenerated composition in a liquid medium to form a pre-aged mixture; subjecting the pre-aged mixture to thermal cycling wherein the cycling occurs within 25° C. and within a temperature range of from 150° C. or more to 300° C. or less to form an aged mixture; and separating the regenerated composition from the liquid medium in the aged mixture.
1 - 53 . (canceled)
54 . A method of obtaining a purified regenerated diacid from a depolymerization of a polyester in a waste material wherein the depolymerization provides a depolymerized mixture comprising a regenerated diol, a regenerated diacid, and a catalyst, the method comprising:
separating a regenerated composition including the regenerated acid and the catalyst from the regenerated diol;
providing the regenerated composition in a liquid medium to form a pre-aged mixture;
subjecting the pre-aged mixture to thermal cycling wherein the cycling occurs within 25° C. and within a temperature range of from 150° C. or more to 300° C. or less to form an aged mixture; and
separating the regenerated composition from the liquid medium in the aged mixture.
55 . The method of claim 54 , wherein the waste material is a waste textile.
56 . The method of claim 54 , wherein the catalyst comprises antimony, germanium, titanium, cobalt, molybdenum, or a mixture thereof.
57 . The method of claim 54 , wherein the catalyst comprises an antimony acetate, antimony trioxide, antimony glycolate, an antimony/metal composite, or a mixture thereof.
58 . The method of claim 54 , wherein the catalyst is present in the regenerated composition in an amount of from greater than 0 ppm to 300 ppm.
59 . The method of claim 54 , 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.
60 . The method of claim 54 , wherein the regenerated diacid comprises an aromatic diacid.
61 . The method of claim 60 , wherein the aromatic diacid comprises a terephthalic acid.
62 . The method of claim 54 , wherein the regenerated diol comprises an aliphatic diol.
63 . The method of claim 62 , wherein the regenerated diol comprises ethylene glycol.
64 . The method of claim 54 , wherein the method comprises:
depolymerizing the polyester to form a depolymerized mixture comprising a regenerated diol, a regenerated diacid, and a catalyst.
65 . The method of claim 64 , further comprising:
clarifying the depolymerized mixture.
66 . The method of claim 65 , further comprising:
decolorizing the depolymerized mixture.
67 . The method of claim 66 , wherein decolorization is conducted using a decolorizing agent comprising activated charcoal.
68 . The method of claim 54 , wherein the method comprises:
isolating the regenerated diacid and the catalyst from the regenerated diol to form a regenerated composition including the regenerated acid and the catalyst.
69 . The method of claim 68 , wherein the isolating step comprises precipitating the regenerated diacid and the catalyst.
70 . The method of claim 69 , wherein the precipitating step comprises adding a strong acid to the depolymerized mixture.
71 . The method of claim 69 , wherein the precipitating step is conducted at two intervals, each at a different pH.
72 . The method of claim 54 , wherein the waste material comprises a polyester and at least one other polymer.
73 . The method of claim 72 , wherein the at least one other polymer comprises cellulose or a polyamide.