Production of High?Purity Hydrogen and Basic Chemicals via High-Efficiency Biomass Conversion

Contributions to the development of efficient renewable?resource conversion for a sustainable energy society.

Research (Rikka) November 28, 2025

Li Liuyun Assistant Professor, Faculty of Engineering

Research aimed at reducing emissions of greenhouse gases such as carbon dioxide and developing renewable energy sources as alternatives to fossil fuels is attracting increasing attention as a means of mitigating global warming. Among these efforts, high?purity hydrogen has gained attention as a potential fuel for automobiles, however, its production still faces challenges such as establishing efficient production technologies and reducing costs. Assistant Professor Li is conducting research on producing high?purity hydrogen by using biomass as a fuel and applying chemical looping combustion—a process that cyclically alternates the reduction and oxidation of iron.

“I have long aspired to help realize a clean hydrogen?based society, which led me to major in energy research at a university in China. During my studies, I attended a lecture by a Japanese researcher and was deeply impressed by the advanced research and technologies presented. After that experience, eventually I was given an opportunity to pursue research at Niigata University.”

In conventional high?temperature gasification, all reactions occur within a single reactor (a device designed to for chemical reactions efficiently), resulting in the generation of mixed gases that require additional separation processes. To address this issue, Assistant Professor Li developed a chemical looping hydrogen production method by separating the reactors so that different reactions occur independently in each unit. This approach successfully enabled the production of high?purity hydrogen. Moreover, because this method does not require equipment to separate the carbon dioxide generated during the hydrogen production process, it offers the potential for significant cost reduction.

“For the practical use of renewable energy, both environmental considerations and resource stability are essential, which is why I chose biomass as the raw material. By advancing the chemical reactions in stages and combining multiple reactors, we can operate each unit to produce the single gas that does not require downstream separation. We will continue conducting demonstration experiments to establish the system and to achieve large?scale production of high?purity hydrogen. The renewable?energy field is evolving every day, and there is even research on producing valuable chemicals directly from carbon dioxide. The growing global interest in renewable energy is incredibly encouraging and motivates me to move forward.”

Profile

Li Liuyun

Assistant Professor, Faculty of Engineering

Ph.D. (Engineering). Specializes in energy engineering. Joined Niigata University in 2010. Her research focuses on energy conversion and valuable chemicals production from Niigata?sourced woody biomass (wood pellets made from forest?thinning residues).

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Beyond the University

For Assistant Professor Li—who saw the sea for the very first time after coming to Niigata—the coastline near campus is a special place.
When research becomes overwhelming, she refreshes herself by enjoying a meal while gazing out at the sea.
“I am fond of the sea because I feel like it gives me power when I look out on it.”