Scientists in the United States and China have developed a groundbreaking one-step method for converting mixed plastic waste into petrol with an impressive efficiency of over 95%. This innovative approach operates at room temperature and ambient pressure, making it less energy-intensive and simpler than conventional plastic-to-fuel methods. The process not only produces petrol and chemical raw materials but also hydrochloric acid, which can be reused in various industrial applications. This advancement promises to support a circular economy by transforming plastic waste into valuable products.
The researchers involved in this work hail from several institutions, including the US Department of Energy-funded Pacific Northwest National Laboratory, Columbia University, the Technical University of Munich, and East China Normal University. Their method aims to address the growing issue of plastic waste, which is largely composed of polyolefins—such as polyethylene and polypropylene—as well as polyvinyl chloride (PVC). These plastics are prevalent in a variety of everyday products including packaging, containers, and medical devices.
To achieve the conversion, the team combines plastic waste with light isoalkanes sourced from refinery byproducts. This approach yields hydrocarbon compounds that fall within the gasoline range, consisting primarily of molecules that have six to twelve carbon atoms. Additionally, the hydrochloric acid produced during the process can be neutralized and reused, potentially replacing more energy-intensive production methods typically used for this chemical.
The researchers highlight the significance of their method in the context of global plastic waste management, as most plastic materials are difficult to recycle. PVC, a particular challenge because of its chlorine content, typically requires dechlorination before any processing to avoid toxic emissions. This new study addresses that challenge by integrating the dechlorination process with the upgrading of discarded PVC into usable hydrocarbons in a single stage.
Efficiency results from the study indicate that when processing PVC materials at 86 degrees Fahrenheit, the method achieves a conversion rate of 95% for soft PVC pipes and 99% for rigid PVC pipes and wires. Even with mixed plastic combinations, the team reported a solid conversion efficiency of 96% at slightly higher temperatures. The authors emphasize that their method is applicable to real-world waste streams, not just laboratory samples.
Additionally, the researchers’ work is characterized as a pioneering step in refining mixed plastic waste into premium petrol efficiently while minimizing process complexity. With global plastic production expected to reach 10 billion tonnes, the team positions their method as a viable pathway for transforming challenging waste streams into valuable resources, thereby supporting sustainability initiatives in the industry.
The findings of this research have been published in the peer-reviewed journal Science.
https://interestingengineering.com/science/us-china-turn-plastic-to-petrol