For more than a decade, two groups at the University of Kentucky Center for Applied Energy Research (CAER) have focused their time and talent investigating and creating new technologies for different methods for capturing carbon dioxide (CO₂) from coal-fired power plants and industrial facilities.

The center’s Power Generation Group, led by Kunlei Liu, has developed a breakthrough post-combustion CO₂ capture technology using advanced engineering and a novel solvent. A second group, CAER’s Biofuels and Environmental Catalysis research team, led by Mark Crocker, has used biology to help capture CO₂. Specifically, they have developed new technologies using algae to capture the carbon dioxide.

Thanks to a new grant from the U.S. Department of Energy’s (DOE) National Energy Technology Laboratory, these two groups are joining forces on an innovative new project that will leverage each group’s expertise. The project is titled “Ammonium Looping with Membrane Absorber and Distributed Stripper for Enhanced Algae Growth.” The $3.7 million project includes DOE funding and industry and university cost-share.

CAER researchers will be developing an NH₃-based looping integrated CO₂ capture and utilization technology that will reduce capture capital and operating costs by 50%. In traditional CO₂ capture systems, the flue gas from the power plant is pretreated for cooling/SO₂ removal, extracted steam is required for solvent regeneration, and the CO₂ must be compressed for downstream utilization or sequestration. The CAER-proposed system will eliminate those steps.  

“This new CO₂ capture and utilization system design marries use of a non-degradable capture solvent with continuous, steady feed of nutrients to the algae,” said Heather Nikolic, research program manager at CAER. “This technology could generate the type of cost savings and production increase needed to make both CO₂ capture and algae utilization more economical and accessible.”

This technology will also boost algae production by 50% by continuously supplying CO₂ and NH₃ in the appropriate growth ratio, compared to an intermittent feeding system.

“We are excited to work with and learn from our CAER colleagues on this project,” said Crocker, associate director at CAER and professor in UK’s Department of Chemistry. “By installing these solvent generators near the algae bioreactor we will provide local, just-in-time distribution of CO₂ and NH₃ at the appropriate ratio, boosting algae production. We believe this engineering advancement will have a significant impact on algae production.”

Researchers from Colorado State University, Vanderbilt University and Trimeric Corporation will partner with CAER on this project.

“Successful development of this technology will allow for more environmentally friendly use of fossil fuels for reliable electricity production,” said Liu, associate director at CAER and associate professor in the UK College of Engineering. “This project will allow us to significantly reduce the complexity and cost of CO₂ capture and biofixation from all sources, whether it is from utility companies, cement manufacturing, or chemical plants. But we also hope it shows the public that carbon capture and utilization technology can be affordable and sustainable.”