Process and system for depolymerizing plastic

A continuous flow process for depolymerizing plastic, comprising:

• a) continuously flowing a mixture containing solid plastic particles in a solvent and in the presence of a catalyst through a line in a heating chamber at a particle speed sufficient to maintain suspension of the plastic particles in the solvent and to prevent the plastic particles from agglomerating and clogging the line;
• wherein the plastic particles consist of polyethylene terephthalate, modified polyethylene terephthalate, polyethylene terephthalate blends, polyethylene naphthalate, polybutylene terephthalate, polyethylene terephthalate glycol, polylactic acid, poly (glycolic acid), poly D,L-lactic-co-glycolic acid, polyethylene 2,5-furandicarboxylate, and copolyesters, or any combination thereof;
• wherein the solvent consists of ethylene glycol, diethylene glycol, glycol ethers, 2-ethyl hexanol, tetramethyl cyclobutanediol, cyclohexanedimethanol, alcohols, ethanol amine, ionic liquids, polar protic solvents, polar aprotic solvents, or any combination thereof;
• b) transferring heat through the line in the heating chamber to heat the mixture to a reaction temperature to start the depolymerization of the plastic particles in the solvent into a homogeneous solution including a liquefied reaction product;
• wherein the reaction temperature is within 20° C. of the melting point of the plastic particles in the heterogeneous mixture;
• wherein the liquified reaction product includes monomers, dimers, or oligomers;
• and
• c) holding the mixture at the reaction temperature for at least one minute.