Reactor for treating polystyrene material
A system for continuously treating recycled polystyrene material includes a hopper/densifier configured to feed recycled polystyrene material into the system. An extruder can turn the recycled polystyrene material into a molten material. In some embodiments, the extruder uses thermal fluids, electric heaters, and/or a separate heater. Solvents, such as toluene, xylenes, cymenes, and/or terpinenes can aid in generating the molten material. The molten material can be depolymerized in a reactor and a catalyst can be used to aid the depolymerizing. In certain embodiments, the catalyst is contained in a permeable container. In some embodiments, copolymers/monomers are grafted onto the depolymerized material. The depolymerized molten material can be cooled via a heat exchanger. The product can be isolated by extraction, distillation, and/or separation. In some embodiments, the product is treated through filtration and absorption media. In some embodiments, multiple reactors are used.
1. A method for continuously treating polystyrene material comprising:
selecting a solid recycled polystyrene material;
heating said solid polystyrene material in an extruder to create a molten polystyrene material;
filtering said molten polystyrene material;
placing said molten polystyrene material through a chemical depolymerization process in a first reactor to create a depolymerized polystyrene material; and
grafting a copolymer/monomer onto said depolymerized polystyrene material to form a grafted product; wherein said copolymer/monomer is
selected from the group consisting of an alkene, an acid, an alcohol, and an acetate;
wherein said grafted product has an average molecular weight between 40000 amu and 200000 amu.
2. The method of claim 1 wherein said filtering involves one selected from the group consisting of a filter bed and a screen changer.
3. The method of claim 1 wherein said chemical depolymerization process employs a catalyst.
4. The method of claim 1 wherein said chemical depolymerization process employs a second reactor.
5. The method of claim 4 wherein said first and second reactors are connected in series.
6. The method of claim 1 wherein said first reactor includes a static mixer.
7. The method of claim 1 of claim 1 further comprising purifying said grafted product, wherein said purification employs one of flash separation, absorbent beds, clay polishing or film evaporators.
8. The method of claim 4 wherein said first and second reactors are connected in parallel such that said first reactor forms said depolymerized polystyrene material and said second reactor creates a second depolymerized polystyrene material.
9. The method of claim 1 wherein said solid polystyrene material has an average molecular weight between 200000 amu and 250000 amu.
10. The method of claim 1 wherein said grafted product as an average molecular weight between 55000 amu and 146000 amu.
11. The method of claim 1 wherein said grafted product as a glass transition temperature between 75° C. and 105° C.
12. The method of claim 1 wherein said recycled polystyrene material is part of a polystyrene material feed, wherein said polystyrene material feed includes up to 25% by weight of non-polystyrene material.
13. The method of claim 1 wherein said recycled polystyrene material includes foam food containers.
14. The method of claim 1 wherein said copolymer/monomer is an acetate.
15. The method of claim 1 wherein said copolymer/monomer is an acid.
16. The method of claim 1 wherein said copolymer/monomer is an alcohol.
17. The method of claim 1 wherein said copolymer/monomer is an alkene.