Two new plastic pyrolysis plants are in the works in the US that could add a new recycling option for plastic trash and increase the supply of some commodity chemicals.
In pyrolysis, a feedstock such as waste plastic is heated in a low-oxygen environment and, instead of burning, breaks down into a mix of simpler hydrocarbons. Tweaking the reaction conditions—such as temperature, pressure, or use of a catalyst—allows operators to get various product mixtures.
The pyrolysis firm Encina is finishing designs with engineers at Worley for a plant that will take in about 160,000 metric tons (t) of waste plastic per year and yield 90,000 t of BTX, a mixture of benzene, toluene, and xylenes normally produced from oil. The firms say the designs are modular, which will let them add capacity later. This will be Encina’s first plant, and founder David Schwedel says the company has four more in the planning stages globally.
Braven Environmental is planning a plant in central Virginia that will take in 65,000 t of plastic per year and produce 50 million L of a diesel-like hydrocarbon blend, according to Michael Moreno, the company’s chief operating officer. The $32 million plant will also produce syngas, which it will burn to fuel the process. The firm expects to create 52 permanent jobs at the site when it opens in mid-2021.
Environmental advocates debate the merits of pyrolysis, citing concerns about scalability, toxic by-products, and derailment of a transition away from single-use plastics. Promoters of such chemical recycling methods counter that they save energy and help keep plastics out of landfills and waterways.
This story was updated on July 10, 2020, to correct an error in the subhead. Encina is considering multiple US locations for its plant, not just Texas.