Abstract: A process is disclosed for the thermal catalytic conversion of polymeric feedstocks, such as scrap tire rubber or plastics, to recover valuable hydrocarbons for reuse. The process includes the solvent washing of -6 mesh polymer feedstock to remove the stabilizing additives which have migrated to the surface of the individual polymer particles. Prior to the reaction step the washed and dried polymer particulate are blended with a metallic halide catalyst system. The mixture of polymer particulate and catalyst are continuously fed to a reactor wherein the conversion of the polymer is accomplished. The reactor and downstream process units are continuously swept by an inert gas which is maintained at just above atmospheric pressure. The combination of the reactor temperature and pressure, with the catalyst system, cause a conversion of the polymer particles to valuable gaseous hydrocarbons.

Abstract: Polymeric feedstocks, such as scrap or waste tires, rubber, and plastics, in a size range of -6 to +25 mesh are washed with an organic solvent to remove stabilizing additives which have migrated to the surface of the polymer particles, thus eliminating the stabilizers from participation in subsequent reactions and allowing the final production of more pure monomeric products. The polymer particles are exposed to ozone under conditions to cause stress cracking, fissuring and cleavage of the polymer feedstock particles. The ozonated polymer particles are depolymerized to produce one or more monomeric compounds, with the reaction taking place rapidly and occurring in the presence of a system of one or more catalysts which may be metallic salts. The depolymerization is accomplished under conditions of elevated temperatures and reduced pressure, the conditions being less severe than those conditions associated with thermal pyrolysis.

Abstract: Scrap rubber chunks from used tires are processed and the monomeric chemicals from which the tire rubber was synthesized are recovered. Rubber chunks reduced to a finely divided size are exposed to gaseous ozone to break down the cross-linked structure of the rubber. Subsequent thermal depolymerization occurs in a reactor chamber. Finely divided silica is introduced within the reactor to prevent agglomeration of rubber particles and to enhance the maintenance of a uniform reactor temperature. Reduced pressure within the reactor permits rapid removal of monomer vapors. Once the monomer vapors are separated, silica and carbon residues are recovered separately for either recycle or disposal.