To address plastic pollution crisis, researchers turn to AI-guided robots, chemical recycling

BUFFALO, N.Y. — Plastic pollution is among the world’s most pressing environmental issues, threatening drinking water, wildlife, food supplies and more.

To address this multifaceted problem, University at Buffalo researchers are developing a novel set of tools that aim to reduce plastic waste and decrease the production of plastic.

This includes a robotic system that relies on machine learning and other technologies to autonomously improve its ability to sort plastics, as well as environmentally responsible solvents and new chemistries that breakdown plastics to make them easier to reuse.

“Not only is this work critically important to our planet, it also contributes to the country’s advanced manufacturing capabilities. It will help meet both consumer demand for and corporate commitments to incorporating recycled plastics into commercial products,” says Paschalis Alexandridis, UB Distinguished Professor in the Department of Chemical and Biological Engineering, who is leading the multidisciplinary effort.

The project is supported by a four-year, $2 million grant the U.S. National Science Foundation (NSF) awarded UB this fall.

It aims to improve the nation’s plastic recycling efforts, which have been muddled since China curtailed plastic waste importing in 2017 with its “National Sword” policy. It also includes public outreach strategies, such as recruiting students underrepresented in STEM (science, technology, engineering and math) fields.

Multidisciplinary research team

Alexandridis, who also holds an appointment in UB’s Department of Civil, Structural and Environmental Engineering, is the grant’s principal investigator. He leads the research team which blends expertise from diverse fields, including computer science, physics, chemistry, chemical engineering, environmental engineering and economics.

Co-investigators from the UB School of Engineering and Applied Sciences include Karthik Dantu, associate professor in the Department of Computer Science and Engineering, and Marina Tsianou, associate professor in the Department of Chemical and Biological Engineering. Additional co-investigators from the Department of Chemistry in the UB College of Arts and Sciences include Javid Rzayev, professor and associate chair, and Luis Velarde, associate professor.

Additional researchers on the project include: John D. Atkinson, associate professor in the Department of Civil, Structural and Environmental Engineering; Amit Goyal, director of UB’s RENEW (Research and Education in eNergy, Environment and Water) Institute and a SUNY Distinguished Professor and SUNY Empire Innovation Professor in chemical and biological engineering; Michael A. Shelly, environmental economist and research assistant professor in the RENEW Institute; and Thomas G. Thundat, SUNY Empire Innovation Professor in the Department of Chemical and Biological Engineering and the RENEW Institute.

AI robots and advanced solvents

The robotic system under development will combine novel sensor technology that can register the molecular signature of each piece of plastic, and machine learning that, on the basis of these molecular signatures, identifies in real-time the specific type of each piece of plastic.

By integrating this system with existing technologies, researchers aim to create an advanced mixed waste sorting process that also captures and reuses other materials often found in plastic recycling streams, such as contaminants and non-polymeric waste, that make recycling difficult and expensive.

In addition to the robotic system, the research team is investigating how to use environmentally responsible solvents to recover desirable plastics from mixed plastic streams. The solvents would separate the plastic from additives or impurities, and render it suitable for reuse in new products.

The approach, known as chemical recycling, has low greenhouse gas emissions compared to other recycling methods.

The research team also will develop new chemical ways for the controlled breakdown of plastic molecules into valuable raw materials. For example, there is a group of plastics called polyolefins that are used in food packaging, toys and other products. Recovered and purified polyolefins could be upcycled to produce waxes used in adhesives, coatings and printing inks. They can also serve as building blocks for additive manufacturing technologies.

Plastics accumulate in landfills and environment

The work is important, Alexandridis says, because plastics are incredibly durable and accumulating in landfills and the environment, where they contaminate waterways and animal life. Recapturing value from end-of-life plastic materials can help push the U.S. and other nations toward the long-term goal of creating a circular economy for plastics, he says.

Equally important, he adds, is the outreach to students and the public.

As such, the researchers are designing a broad range of activities to recruit a diverse group of undergraduate students from local two- and four-year colleges who can participate in research and share knowledge with local communities. Additional outreach on the importance of recycling is planned for middle and high school students, and the public.

The ideation of the project stemmed from ongoing multidisciplinary efforts to improve plastics recycling led by RENEW, such as the institute’s new state-funded effort to improve plastics recycling.

Additionally, the new NSF-funded project compliments other research activities at UB such as UB’s Sustainable Manufacturing and Advance Robotic Technologies (SMART) Community of Excellence. It also involves contributions from external partners, including Honeywell and Modern Corp.

Funding comes from NSF’s Emerging Frontiers in Research and Innovation (EFRI) program.