Concept: The Center for Plastics Innovation (CPI) of the University of Delaware (UD) has formulated a direct approach to convert single-use plastic waste into ready-to-use molecules for jet fuels, diesel, and other lubricants. UD researchers used a chemical method ‘catalytic hydrocracking’ to break down polyolefins, a type of plastic that is difficult-to-recycle.
Nature of Disruption: The catalytic hydrocracking method breaks down plastic solids such as high-density polyethylene, polypropylene, and polystyrene in ordinary plastic bags and bottles into smaller carbon molecules. Hydrogen molecules are added on either end to stabilize the material. The catalyst used in the process is a composite medium made up of zeolite and mixed platinum oxide. As the catalyst is applied to solid plastic, it breaks down into smaller molecules. Researchers claim that although each catalyst is ineffective on its own to break the plastic, combining platinum and zeolite improves the effectiveness. In short, platinum causes the first crack in polyolefins following which zeolite takes over and breaks it down even further. As the acidity of zeolite is combined with platinum nanoparticles, high yields of up to 85 % of liquid hydrocarbons are achieved with very little solid as a by-product. By adjusting the ratios of the two catalysts, the resulting mixture can be optimized to produce a variety of fuels, ranging from jet fuel to gasoline for vehicles.
Outlook: Hard-to-recycle polyolefins make up 60 to 70% of all plastics produced in the world. Therefore, reducing plastic waste by chemically turning it into fuels can help to drive a circular economy, in which goods are recycled into new products rather than being tossed out at the end of their lifespan. The recycled materials may be reused to create the same product or, in the case of oils, upcycled into higher-value goods, resulting in both economic and environmental benefits. UD researchers already filed a patent in 2020 for the process and carrying out further research. They believe that the commercialization of the catalytic hydrocracking process can occur within five to 10 years. UD also has plans to apply a similar method to break down other types of plastic materials.