Systems and methods for recycling waste plastics are provided, including a system for recovering styrene monomer from waste polystyrene. The system includes a mixing, heating and compacting apparatus to receive a supply of waste polystyrene and to output a densified polystyrene containing melt; a pyrolysis reactor configured to receive the densified polystyrene containing melt and a supply of recycled oligomers, pyrolyze the densified polystyrene containing melt and the recycled oligomers, and output a hydrocarbon gas stream and a solids residue stream; a quenching apparatus configured to receive the hydrocarbon gas stream output from the pyrolysis reactor and condense out oligomers for routing upstream to the pyrolysis reactor to be combined as the supply of recycled oligomers with the densified polystyrene containing melt, and to discharge an altered hydrocarbon gas stream for further processing; and a condenser configured to receive the altered hydrocarbon gas stream from the quenching apparatus and condense out styrene to form a styrene monomer oil product.

Systems and methods for recycling waste plastics are provided, including a system for recovering styrene monomer from waste polystyrene. The system includes a mixing, heating and compacting apparatus to receive a supply of waste polystyrene and to output a densified polystyrene containing melt; a pyrolysis reactor configured to receive the densified polystyrene containing melt and a supply of recycled oligomers, pyrolyze the densified polystyrene containing melt and the recycled oligomers, and output a hydrocarbon gas stream and a solids residue stream; a quenching apparatus configured to receive the hydrocarbon gas stream output from the pyrolysis reactor and condense out oligomers for routing upstream to the pyrolysis reactor to be combined as the supply of recycled oligomers with the densified polystyrene containing melt, and to discharge an altered hydrocarbon gas stream for further processing; and a condenser configured to receive the altered hydrocarbon gas stream from the quenching apparatus and condense out styrene to form a styrene monomer oil product.

A method of producing a five-carbon ring derivative-containing polyurethane involves introducing a DCPD-derived 5-carbon cyclic compound into a polyurethane material and effectuating polymerization in the presence of a solvent of a low boiling point and low toxicity to produce a five-carbon ring derivative-containing polyurethane of a high molecular weight.

A method of producing a five-carbon ring derivative-containing polyurethane involves introducing a DCPD-derived 5-carbon cyclic compound into a polyurethane material and effectuating polymerization in the presence of a solvent of a low boiling point and low toxicity to produce a five-carbon ring derivative-containing polyurethane of a high molecular weight.

A method of producing a five-carbon ring derivative-containing polyurethane involves introducing a DCPD-derived 5-carbon cyclic compound into a polyurethane material and effectuating polymerization in the presence of a solvent of a low boiling point and low toxicity to produce a five-carbon ring derivative-containing polyurethane of a high molecular weight.

Methods and systems for recovering dicyclopentadiene from pygas are provided. Methods can include heating pygas to generated heated pygas, recovering a C.sub.5 fraction from the heated pygas, and dimerizing cyclopentadiene from the C.sub.5 fraction to form dicyclopentadiene. Methods can further include recovering the C.sub.5 fraction from the pygas in a depentanizer column. Other methods can include heating pygas including dicyclopentadiene to form cyclopentadiene and hydrogenating cyclopentadiene in the pygas to form cyclopentane.

Methods and systems for recovering dicyclopentadiene from pygas are provided. Methods can include heating pygas to generated heated pygas, recovering a C.sub.5 fraction from the heated pygas, and dimerizing cyclopentadiene from the C.sub.5 fraction to form dicyclopentadiene. Methods can further include recovering the C.sub.5 fraction from the pygas in a depentanizer column. Other methods can include heating pygas including dicyclopentadiene to form cyclopentadiene and hydrogenating cyclopentadiene in the pygas to form cyclopentane.

Methods and systems for recovering dicyclopentadiene from pygas are provided. Methods can include heating pygas to generated heated pygas, recovering a C.sub.5 fraction from the heated pygas, and dimerizing cyclopentadiene from the C.sub.5 fraction to form dicyclopentadiene. Methods can further include recovering the C.sub.5 fraction from the pygas in a depentanizer column. Other methods can include heating pygas including dicyclopentadiene to form cyclopentadiene and hydrogenating cyclopentadiene in the pygas to form cyclopentane.

According to one or more embodiments presently disclosed, a method of catalytically converting polystyrene may include contacting polystyrene with a catalyst to form a product comprising ethylbenzene. The catalyst may include oxidized iron, oxidized cobalt, and oxidized copper. The catalyst may further include a mesoporous support material with pores having an average pore diameter of from 2 nm to 50 nm.

According to one or more embodiments presently disclosed, a method of catalytically converting polystyrene may include contacting polystyrene with a catalyst to form a product comprising ethylbenzene. The catalyst may include oxidized iron, oxidized cobalt, and oxidized copper. The catalyst may further include a mesoporous support material with pores having an average pore diameter of from 2 nm to 50 nm.