Li to Lead Development of Transformational Energy Technology Funded by Department of Energy

June 24, 2021 – A multi-institutional team led by UC Irvine chemical engineer Han Li was awarded $1.8 million from the U.S. Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E).  The funds will be used to create new clean energy processes that more efficiently convert waste into commodities and biofuels and reduce its carbon footprint.

“I am very honored to receive this award and excited to carry out the proposed research,” said Li, principal investigator and assistant professor of chemical and biomolecular engineering. “This is a bold idea, and I am pleased to see that it fits well into ARPA-E's model of funding high-risk, high-impact work.”

If successful, her project will be the first biological platform to convert carboxylic acids into a broad range of fuels and commodities with greater than 100% carbon efficiency.

Currently, ethanol biofuel and a growing number of other plant-based products are made almost exclusively by fermentation. Existing methods for producing ethanol can waste more than a third of the carbon in feedstock (raw plant materials such as corn, wheat and soy) as carbon dioxide during the fermentation step alone. This waste adds greenhouse gas emissions, limits product yields and squanders valuable carbon feedstock.

Preventing the loss of carbon as carbon dioxide during bioconversion, or potentially incorporating external sources of carbon dioxide, could lower emissions and increase the yield of bioconversion processes.

To solve the problem of lost carbon, Li’s team is focusing on carboxylic acids, organic compounds often used in industrial applications. Compared with grain-derived sugars, carboxylic acids could be produced in large quantities from food and industrial wastes. This could serve as a more scalable and economical feedstock for biofuel and biochemical production. However, natural biological pathways for carboxylic acid conversion suffer from a low carbon yield.

“Our multi-institutional team proposes a cell-free enzymatic process to address this challenge,” said Li. The proposed system uses a unique, stronger-than-nature equivalent carrier to overcome a thermodynamic hurdle in carboxylic acid utilization that currently results in lost carbon. The team’s process uses a novel single carbon pathway that elongates and upgrades the product.

Li said, “This work aims at both replacing fossil fuels and decreasing carbon dioxide emission, which are important steps toward the nation's carbon-neutral future.”

In addition to Li, the team includes Gregory Weiss, UCI, chemistry; Justin Siegel, UC Davis; and Ramon Gonzalez, University of South Florida.

Li’s research team is one of 15 teams this year to have received this competitive award from ARPA-E’s Energy and Carbon Optimized Synthesis for the Bioeconomy (ECOSynBio) program. ECOSynBio focuses on developing advanced synthetic biology tools to engineer novel biomass conversion platforms and systems that are more efficient and produce fewer emissions than current fermentation processes widely used in biorefining.

– Tonya Becerra