LSU Researchers Create Low-Cost Method to Recycle Plastic

SEATTLE (Scrap Monster):  LSU researchers have created a new, low-cost way to break down plastic, a potential breakthrough that could save billions of dollars and eliminate billions of tons of plastic pollution.

“Getting plastics to the recycling plant is only half the battle. The other half is reusing that plastic waste to create new products,” said James Dorman, program manger with the U.S. Department of Energy and former LSU Chemical Engineering professor. “Some estimates show as much as 95 percent of plastics in the U.S. ends up in landfills and incinerators. Our process breaks down commercial plastics, including polystyrene and high- and low-density polyethylene, so recycled material can be seamlessly integrated into new products.”

Dorman and LSU Chemical Engineering Professor Kerry Dooley use electromagnetic induction heating along with special magnetic materials and catalysts to break down different types of plastic.

Electromagnetic waves melt the plastics from the inside out, which requires far less energy. Dorman and Dooley’s process also produces only small amounts of unwanted byproducts such as methane, a powerful greenhouse gas, unlike conventional recycling. The conventional method of melting plastic waste, pyrolysis, requires high temperatures and produces gases like carbon dioxide and hydrogen.

Dorman and Dooley’s method works at lower temperatures and offers more precise control of the breakdown process. Their method can be tailored to handle food residues and other contaminants that help limit plastics recycling. For example, recyclers commonly send plastic containers that still contain food – yogurt for example – to the landfill because the residue taints the recycled material.

Most plastic starts with fossil fuels. Refiners heat oil and natural gas to “crack” the large molecules into smaller molecules, among them ethylene and propylene. Those chemicals are the building blocks used to make a variety of plastics. By linking the monomers, plastics manufacturers create a long chain molecule called a polymer, or a plastic.

“Our extraction process retains key, core monomers, so they can be reinserted into the polymerization process,” Dorman said. “For example, we can pull the ethylene from the polyethylene during recycling and use it to make new polyethylene.”

Ethylene and propylene are extremely valuable. The global market for ethylene alone is estimated at $150 billion.

“By recycling these chemicals, we can help reduce the need for new fossil fuels and lower greenhouse gas emissions,” Dooley said. “Basically, our extraction process helps clean up the environment and creates a way to make money from what was once trash.”

“This breakthrough in plastic recycling is a crucial step in our Scholarship First Agenda mission to build a research platform for energy resilience,” said LSU Vice President of Research and Economic Development Robert Twilley. “By innovating processes that increase the recycling of carbon-based materials and reduce carbon emissions, LSU is addressing the challenge of plastic waste and helping to create a sustainable energy future.”

Dorman and Dooley have worked with the LSU Office of Innovation & Technology Commercialization (ITC) to pursue patent protection for their invention.

“We’re excited about helping Drs. Dorman and Dooley explore the commercial possibilities for this cutting-edge technology,” said Daniel Felch, LSU ITC senior commercialization officer.

Courtesy: www.possierpress.com