Ames National Laboratory scientists turn plastic waste into sulfur-free diesel fuel

10 May 2024 --- US Department of Energy’s Ames National Laboratory scientists have engineered a chemical conversion process to transform plastic waste into cleaner-burning diesel fuel.

Led by Aaron Sadow and Wenyu Huang, the research team has unveiled a solution that is expected to address two pressing global challenges: plastic pollution and transportation emissions. 

The researchers emphasize plastics are necessary materials with properties that lead to many applications, including safe food storage, lightweight electronics and sanitary medical equipment. 

However, plastic waste, particularly from single-use products, poses a significant environmental hazard, persisting for thousands of years in landfills and polluting natural habitats and water sources. Meanwhile, the transportation sector, reliant on diesel for power and mobility, contributes substantially to air pollution and climate change.

“We are converging on a crisis made worse by emissions impacting air quality and climate change that requires us to use our natural resources more efficiently, including the fossil resources used to make plastics and liquid fuels,” says Sadow. 

“But by looking holistically at energy and fuels, chemicals and materials, and their natural supply, we can design sustainable solutions for our plastic waste and energy problems.”

Catalysis conversion
The newly devised process, a catalytic conversion method, directly converts plastic waste into diesel fuel in a single step. 

Unlike conventional catalysts, which yield a range of products necessitating energy-intensive separation processes, the catalysts employed in this process exhibit selectivity, yielding diesel fuel directly from the reaction.

The chemical used by the Ames Lab scientists breaks apart the plastic polymers selectively into diesel fuel during the reaction process. 

“There is a competitive advantage to making it from plastic if you can bypass the massive refineries, and that’s exactly what our technology does,” Sadow explains.

Furthermore, the scientists say the resulting diesel is notably cleaner than its counterpart, devoid of sulfur — a common pollutant in traditional diesel production. 

“It’s hard to remove sulfur from crude oil. That’s an expensive part of the refining process,” Huang elaborates. “Plastic inherently doesn’t have sulfur because it’s already refined.”

Multiple patent applications have been filed for various aspects of the technology, underscoring its potential for widespread adoption and commercialization.

Edited by Radhika Sikaria