PhD Graduate Lingxiang Zhu publishes in Energy and Environmental Science Journal

Kemper County Energy Facility.

Kemper County Energy Facility: a 582 MW power plant filters carbon before burning fossil fuels in Kemper County, Mississippi. Courtesy of U.S. DOE NETL Document Library.

Published January 5, 2018

Membranes Boost Production of Green Hydrogen Fuel with CO₂ Capture

Carbon dioxide (CO₂) capture, sequestration, and utilization is an important approach to mitigating CO₂ emissions to the environment. A key strategy is to decarbonize fossil fuels before burning them. This process involves the conversion of fossil fuels into a gas mixture of hydrogen (H₂) and CO₂, which must then be separated to obtain CO₂ for sequestration/utilization and H₂ fuel for use. Membrane technology has inherent advantages for this separation because of its high energy efficiency, small footprint, and ease of scale-up.

Lingxiang Zhu

Lingxiang Zhu.

Lingxiang Zhu, a PhD student from Dr. Haiqing Lin’s group, has been focusing on the development of high-performance membranes for H₂ purification and CO₂ capture since 2014. His recent research demonstrated a new approach to manipulating polymer structure by acid doping, leading to superior H₂/CO₂ separation performance. Specifically, polybenzimidazole (PBI) was doped with polyprotic acids such as phosphoric acid and sulfuric acid. These acids cross-link PBI backbones, enhance chain packing efficiency, and drastically decrease free volume, improving the H₂/CO₂ selectivity to an unprecedented value of 140 at 150 °C. This selectivity is the highest among known polymers. The simple yet elegant approach of acid doping provides a flexible and exciting platform to enhance polymer chain-packing efficiency, and thus achieve sharp molecular size separation in polymers. The work was published in Energy & Environmental Science, which is a monthly journal published by the Royal Society of Chemistry with an impact factor of 29.5. [Read the full paper]

Lingxiang just defended his thesis entitled “Advanced polymeric membranes for H₂ purification and CO₂ capture” in December 2017, and he will start a postdoctoral training in coming summer. He plans to pursue an academic career, focusing on education and research in chemical engineering and membrane technology.