Electrifying landfill plastic is ASU professor's goal

The United States uses about 37 million tons of plastic every year, according to management consulting firm McKinsey & Company. Almost half is single-use, disposable plastic from the packaging and food service industries that largely ends up in landfills. This single-use plastic is difficult to recycle, and as it breaks down in landfills, it releases toxic chemicals into the surrounding soil. This contaminates groundwater and disrupts ecosystems.

To solve this problem, a team of Arizona State University researchers is using novel technologies to study the manufacturability of upcycling plastic waste into high-value carbon fiber materials to advance the electric vehicle, or EV, industry. As electric vehicles gain popularity, the industry expects that there will soon be a spike in demand for carbon fiber materials.

“With one project, our goal is to make sustainability strides in two significant areas,” said Kenan Song, the project lead and assistant professor of manufacturing engineering. “We are addressing and leveraging the negative impacts of plastic waste to impact decarbonization efforts via the EV industry.”

Song specializes in advanced manufacturing research in the School of Manufacturing Systems and Networks, part of the Ira A. Fulton Schools of Engineering. He leads the Advanced Materials Advanced Manufacturing Lab on ASU’s Polytechnic campus, which explores the advanced manufacturing, design, fabrication, characterization and simulation of advanced composite materials with a focus on increased performance in practical applications.

Song’s project, “Textile Engineering of Polyethylene Recycling for Future Vehicles,” is supported by the Zimin Institute for Smart and Sustainable Cities at ASU, an initiative that strives to create new and advanced technologies to make cities safer, more secure, healthier, sustainable and resilient.

“The proposed work attacks a significant and growing local, regional, national and worldwide problem — that of recycling plastics created by cities’ inhabitants,” said Greg Raupp, Zimin Institute director and a professor of chemical engineering in the Fulton Schools. 

From landfill waste to carbon fiber materials

Song explained that by applying precisely controlled heat treatment via a novel co-axial spinning method, specific plastics can be transformed into durable carbon fibers. Song and his team also use LightFiber, a green technology developed by ASU’s Global Security Initiative that is not currently deployed in commercial manufacturing settings, to aid in scaling this process.

“Specific plastics will undergo an evolution of their crystallization structures that will form into carbon fiber materials,” he says. “These carbons’ unique microstructures can be electrically conductive, thermally dissipative or structurally robust.”

These properties, combined with more efficient manufacturability of carbon fibers, enable the creation of lightweight and durable materials that lend to efficient structural support and even carbon dioxide absorption that all contribute to decreased fuel consumption and improved vehicle performance.

“Carbon fiber-reinforced electrodes in EV batteries, composites for vehicle frames or fillers in vehicle tires — all enhance the performance of each part and the vehicle as a whole,” Song said.

To address the Zimin Institute’s overarching goal of eliminating plastic waste in future cities, the process to transform plastic waste into carbon fibers must be scalable through advanced manufacturing methods.

Along with enabling durable carbon fiber production from recycled plastics, LightFiber offers an easy-to-scale manufacturing platform that allows the research team to produce thousands of meters of carbon fibers within hours. This could help turn the concept into a cost-effective and commercially viable solution.

“This research is useful for waste management and plastic recycling in the future, which is crucial for the next generation,” said Varunkumar Thippanna, a systems engineering doctoral student and the project’s lead researcher.

He leads efforts to research and analyze different types of plastic waste, conduct co-axial spinning experiments, apply the heat treatment process and characterize the improvement of the properties of composite fibers when reinforced with upcycled plastics.

Raupp said he believes that this project is in alignment with the new technology solutions needed to fulfill the Zimin Institute’s sustainability mission.  

“I look forward to the synergy of this project with the rapidly growing investment in Arizona by companies large and small in electric vehicle and EV battery innovation and manufacturing,” he said.