Researchers at Rice University have developed a groundbreaking method to extract high-yield hydrogen from mixed waste plastics, without the need for sorting by type or washing. This pioneering approach also yields high-value graphene, opening up new possibilities for sustainable and cost-effective hydrogen production.
According to Kevin Wyss, a Rice doctoral alumnus and lead author of the study published in Advanced Materials, this innovative method could potentially produce clean hydrogen at a fraction of the current market cost, essentially making it free. In comparison, “green” hydrogen currently costs approximately $5 for just over two pounds. This development has the potential to revolutionize the hydrogen production industry, which currently relies heavily on fossil fuels and generates significant carbon dioxide emissions.
James Tour, Rice’s T. T. and W. F. Chao Professor of Chemistry and a professor of materials science and nanoengineering, explained the urgent need for cleaner hydrogen production methods, stating, “Demand for hydrogen will likely skyrocket over the next few decades, so we can’t keep making it the same way we have up until now if we’re serious about reaching net-zero emissions by 2050.”
The innovative process involves subjecting plastic waste samples to rapid flash Joule heating for approximately four seconds, elevating their temperature to a staggering 3100 degrees Kelvin. This extreme heat vaporizes the hydrogen contained within the plastics, leaving behind high-quality graphene.
However, during the initial stages of development, the researchers observed volatile gases being emitted from the process. These gases were a mix of small hydrocarbons and hydrogen, but their exact composition was not initially clear. With funding from the US Army Corps of Engineers, the research team acquired the necessary equipment to precisely analyze and characterize these vaporized contents.
Wyss explained the significance of this breakthrough, stating, “We know that polyethylene, for example, is made of 86 percent carbon and 14 percent hydrogen, and we demonstrated that we are able to recover up to 68 percent of that atomic hydrogen as gas with a 94 percent purity. Developing the methods and expertise to characterize and quantify all the gases, including hydrogen, produced by this method was a difficult but rewarding process.”
This innovative approach holds immense promise in addressing two critical challenges: plastic pollution and the greenhouse gas-intensive production of hydrogen. By turning plastic waste into a valuable resource for clean hydrogen production, Rice University’s groundbreaking technology could play a pivotal role in advancing sustainability and combating environmental problems. It represents a significant step toward a cleaner, more sustainable future where waste is transformed into valuable assets, ultimately contributing to a greener and more efficient energy landscape.
