Researchers in Georgia Tech’s School of Chemical & Biomolecular Engineering (ChBE) have won two grants from the Department of Energy (DOE) for projects designed to enhance the operational efficiency of systems that reduce carbon dioxide emissions from power plants.

One project, led by Assistant Professor Ryan Lively, is titled “Enabling 10mol/kg Swing Capacity via Heat Integrated Sub-ambient Pressure Swing Adsorption.” It will last for three years (total funding: $2,491,483) and will also involve ChBE faculty members Yoshiaki Kawajiri, Matthew Realff, David Sholl, and Krista Walton.

The project aims to drastically improve the efficiency of a process called pressure swing adsorption, through which carbon dioxide (CO2) emissions are separated from power plant flue gases. To better capture CO2, the researchers will cool and pressurize the flue gases.

Historically, it’s been believed that it would be too costly to treat the flue gases in this fashion, Lively explains, because power plants release so much CO2 into the atmosphere – 9 to 10 tons per minute.

“However, our team has devised ways to efficiently recover the energy required to cool and compress the flue gases,” he says.

Cooling the gas will enable highly efficient operation of pressure swing adsorption systems that employ metal organic frameworks supported by hollow fiber sorbents, which create more compact gas-separation devices.

“We’re rethinking the way we remove CO2 from power plants,” Lively says. “Through novel process engineering, state-of-the-art materials that remove CO2 can perform 10 times better than they would at ambient conditions.”

The other project funded by DOE – spearheaded by ChBE’s Ryan Lively and collaborators at Praxair, Inc. (an industrial gas company) – is titled “Improving Energy Efficiency of Air Separation via Hollow Fiber Sorbents.” It will last for 18 months (total funding: $1,174,277) and involve ChBE faculty members Christopher Jones, William Koros, and Matthew Realff.

The project aims to improve the industrial energy efficiency of gas separation technology associated with the creation of CO2 and hydrogen.

Known as “pre-combustion CO2 capture,” the technology involves gasifying the fuel for power production into hydrogen and CO2 at high pressures. This high-pressure CO2 is easier to capture than the low-pressure CO2 found in power plant flue gas.

“One of the major issues with this approach is the need to separate large quantities of air to assist in the gasification process,” Lively explains.

To make this large-scale air separation technology economically attractive, the researchers will develop and test a rapidly cycled pressure swing adsorption (RCPSA) system for separating the gases up to five times more efficiently than traditional cryogenic technology. The sub-ambient-temperature RCPSA system will involve advanced zeolites supported by hollow fiber sorbents.

Together, these two new DOE funded projects will support four post-doctoral researchers and four graduate students in ChBE at Georgia Tech.