Chemical recycling of solvolysis terephthalyl column bottoms coproduct streams

A method for processing waste plastic, said method comprising:

• (a) separating a stream of mixed plastic waste (MPW) into a polyethylene terephthalate-enriched (PET-enriched) stream and a polyolefin-enriched stream (PO-enriched) stream;
• (b) subjecting at least a portion of said PET-enriched stream to solvolysis in a solvolysis facility to form a principal glycol product, a principal terephthalyl product, and at least one coproduct stream, wherein said coproduct stream comprises a terephthalyl column bottoms coproduct stream;
• and
• (c) introducing at least a portion of said terephthalyl column bottoms coproduct stream from said solvolysis facility into at least one of the following:
• (i) a partial oxidation (POX) gasification facility;
• (ii) a pyrolysis facility;
• (iii) a solidification facility;
• (iv) a cracker facility;
• and (v) an energy generation/energy production facility.

A solvolysis coproduct composition formed within a solvolysis facility for processing polyester terephthalate-containing waste plastic to form a principal glycol product and a principal terephthalyl product using a solvent, said composition comprising:

• at least 70 weight percent of oligomers comprising polyester moieties;
• and
• at least 1 part per billion (ppb) by weight and not more than 25 weight percent of substituted terephthalyl components, based on the total weight of the composition,
• wherein said composition has a mid-range boiling point higher than the boiling point of said terephthalyl.