The New Process Vaporizes Plastic To Produce Gas For Manufacturing New Recycled Plastics

A new chemical process can essentially evaporate the dominant plastics in today's waste streams and convert them into hydrocarbon based materials for new plastics. Suitable for most major plastics: polyethylene and polypropylene. This catalytic process was developed by the University of California, Berkeley and is applicable to two main types of post consumer plastic waste: polyethylene and polypropylene. Polyethylene is used for most disposable plastic bags, while polypropylene is used for hard plastics such as microwave tableware and luggage. This process can also effectively degrade the mixture of these plastics. If scaled up, this process can help create a circular economy for many disposable plastics. Plastic waste will be converted back into monomers used to manufacture polymers, thereby reducing the fossil fuel required for producing new plastics. Transparent plastic water bottles made of polyethylene terephthalate (PET), a type of polyester, were designed in the 1980s to be recycled in this way. But compared to polyethylene and polypropylene plastics (known as polyolefins), polyester plastics have a very small volume. John Hartwig, a chemistry professor at the University of California, Berkeley who led the research, said, "There are large amounts of polyethylene and polypropylene in our daily necessities, from lunch bags to laundry soap bottles to milk cans - many things around us are made of these polyolefins. In principle, what we can do now is to bring these objects back to the starting monomers through the chemical reactions we designed, which break the usually stable carbon carbon bonds. By doing so, we are closer than anyone to endowing polyethylene and polypropylene with the same recyclability as polyester in water bottles. Hartwig, graduate student Richard J. "RJ" Conk, chemical engineer and UC Berkeley graduate school professor Alexis Bell, and their colleagues will publish details of the catalytic process in the journal Science on August 29th.