Abstract: A process for forming reactants useful in the manufacture of polyethylene terephthalate includes the steps of: (a) contacting recyclable polyethylene terephthalate with ammonium hydroxide whereby a mixture of ammonium terephthalate and ethylene glycol is formed, (b) separating the ammonium terephthalate, and (c) heating said ammonium terephthalate at a temperature from about 225° C. to about 300° C. to produce terephthalic acid.

Abstract: Disclosed herein is a process for depolymerizing and purifying recyclable PET comprising the steps of: (a) conducting acetolysis on recyclable PET to form terephthalic acid and ethylene glycol diacetate; (b) reacting the terephthalic acid with methanol to form dimethyl terephthalate; and (c) reacting the dimethyl terephthalate with the ethylene glycol diacetate under transesterification and polycondensation conditions to form both a PET product with an unusually low concentration of copolymerized diethylene glycol and methyl acetate. Further disclosed is a process wherein the above process is efficiently combined with a process for producing cellulose acetate. In addition to steps (a)-(c), the combination process additionally comprises the steps of: (d) carbonylating the methyl acetate with carbon monoxide to form acetic anhydride; and (e) acetylating cellulose with the acetic anhydride to form cellulose acetate and acetic acid, with the acetic acid being useful in step (a).

Abstract: Disclosed herein is a process for depolymerizing and purifying contaminated post-consumer polyester. In the process, depolymerization is effected by way of glycolysis in an agitated reactor vessel. The process includes the steps of contacting a contaminated polyester with an amount of a glycol to provide a molar ratio of greater than about 1 to about 5 total glycol units to total dicarboxylic acid units at a temperature between about 150 to about 300° C. and an absolute pressure of about 0.5 to about 3 bars. This reaction is conducted for a time sufficient to produce, in the reactor, an upper layer having a relatively low density contaminant floating on top of a lower layer which includes a relatively high density depolymerized oligomer of the polyester, and separating the upper layer from the lower layer. The layers may be separated by removing the upper layer from the reactor in a first stream and removing said lower layer from the reactor in a second stream.