Abstract: A method of pretreating polystyrene-containing materials to form a solution of polystyrene in a processing solvent from which the styrene in the polystyrene in the materials is reclaimed. The materials are mixed with an environmentally acceptable pretreating solvent having a lower boiling point than the processing solvent, typically at a location remote from the reclamation plant. The pretreating solvent is selected from the group consisting of d-limonene, l-limonene, dipentene, and blends thereof. Prior to actual processing to reclaim styrene, the pretreating solvent is substantially replaced with the processing solvent. The pretreating solvent may be recovered for reuse.

Abstract: A method of reclaiming styrene from polystyrene-containing materials contaminated with animal fats and/or vegetable oils. A solution of polystyrene from such materials in a solvent is heated in distillation equipment to depolymerize the polystyrene and produce a styrene fraction and a heavier fraction, the styrene fraction being separated from the heavier fraction. Prior to heating, an inert gas is used to purge the distillation equipment of oxygen. The method preferably is carried out at the lowest temperature which will achieve the desired rate of depolymerization.

Abstract: Methods of using styrene oil, its fractions, and combinations thereof as working fluids, lubricants, fuels and solvents.

Abstract: In the method for reclaiming styrene monomer from polystyrene, polystyrene is mixed with a solvent and heated to approximately 300.degree. C. to 400.degree. C. to depolymerize the polystyrene to produce a styrene monomer fraction and a heavier fraction of partial depolymerization products. The styrene fraction is separated from the heavier fraction to recover the styrene monomer and polystyrene partial depolymerization products. In a preferred embodiment, the solvent comprises a "styrene oil" which results from the incomplete depolymerization of polystyrene, at least a portion of which is recycled to mix with polystyrene. The method is useful in reclaiming styrene monomer from napalm, foamed polystyrene, and other polystyrene products. In the case of reclamation of napalm, the method also includes the steps of separating and recovering benzene and gasoline.

Abstract: In the method for reclaiming styrene monomer from polystyrene, polystyrene is mixed with a solvent and heated to approximately 300.degree. C. to 400.degree. C. to depolymerize the polystyrene to produce a styrene monomer fraction and a heavier fraction of partial depolymerization products. The styrene fraction is separated from the heavier fraction to recover the styrene monomer and polystyrene partial depolymerization products. In a preferred embodiment, the solvent comprises a "styrene oil" which results from the incomplete depolymerization of polystyrene, at least a portion of which is recycled to mix with polystyrene. The method is useful in reclaiming styrene monomer from napalm, foamed polystyrene, and other polystyrene products. In the case of reclamation of napalm, the method also includes the steps of separating and recovering benzene and gasoline.