Signal UCLA-Ewha Team Converts Mixed Plastic Waste Directly Into High-Purity Hydrogen

Summary

Researchers at UCLA Samueli School of Engineering and South Korea's Ewha Womans University have developed an alkaline thermal treatment process that converts a mixture of the three most common plastics—PET, PE, and PP—directly into hydrogen fuel of over 90% purity without sorting, published in the Proceedings of the National Academy of Sciences on July 31, 2026. Because PE and PP are chemically inert under alkaline conditions, the team added a mild thermal oxidation pretreatment step that introduces oxygen-containing functional groups, allowing all three plastics to react efficiently. Carbon released during the reaction is captured by sodium hydroxide and locked into solid sodium carbonate rather than released as CO2, with more than 75% of the original plastic carbon converted to stable carbonate or liquid organic residue and less than 13% escaping to the atmosphere. The process also runs 300-400°C cooler than conventional steam gasification, reducing energy demand, at a time when only 9% of discarded plastic is recycled worldwide because sorting by type is labor-intensive and costly. Co-author Ah-Hyung "Alissa" Park, dean of UCLA Samueli, said the approach "solves two urgent global problems at the same time."