IMPACCT

A team of six faculty members at Georgia Tech Research Corporation is developing an enhanced membrane by fitting metal organic frameworks, compounds that show great promise for improved carbon capture, into hollow fiber membranes. This new material would be highly efficient at removing CO2 from the flue gas produced at coal-fired power plants.

Lawrence Livermore National Laboratory (LLNL) is designing a process to pull CO2 out of the exhaust gas of coal-fired power plants so it can be transported, stored, or utilized elsewhere. Human lungs rely on an enzyme known as carbonic anhydrase to help separate CO2 from our blood and tissue as part of the normal breathing process. LLNL is designing a synthetic catalyst with the same function as this enzyme. The catalyst can be used to quickly capture CO2 from coal exhaust, just as the natural enzyme does in our lungs.

General Electric (GE) Global Research and the University of Pittsburgh are developing a unique CO2 capture process in which a liquid absorbent changes into a solid upon contact with CO2. Once in solid form, the material can be separated and the CO2 can be released for storage by heating. Upon heating, the absorbent returns to its liquid form, where it can be reused to capture more CO2. The approach is more efficient than other solvent-based processes because it avoids the heating of extraneous solvents such as water.

The University of Kentucky is developing a hybrid approach to capturing CO2 from the exhaust gas of coal-fired power plants. In the first, CO2 is removed as flue gas is passed through an aqueous ammonium-based solvent. In the second, carbon-rich solution from the CO2 absorber is passed through a membrane that is designed to selectively transport the bound carbon, enhancing its concentration on the permeate side. The team's approach would combine the best of both membrane- and solvent-based carbon capture technologies.

Massachusetts Institute of Technology (MIT) and Siemens Corporation are developing a process to separate CO2 from the exhaust of coal-fired power plants by using electrical energy to chemically activate and deactivate sorbents—materials that absorb gases. The team found that certain sorbents bond to CO2 when they are activated by electrical energy and then transported through a specialized separator that deactivates the molecule and releases it for storage.

A team led by three professors at Texas A&M University is developing a subset of metal organic frameworks that respond to stimuli such as small changes in temperature to trap CO2 and then release it for storage. These frameworks are a promising class of materials for carbon capture applications because their structure and chemistry can be controlled with great precision.

Codexis is developing new and efficient forms of enzymes known as carbonic anhydrases to absorb CO2 more rapidly and under challenging conditions found in the gas exhaust of coal-fired power plants. Carbonic anhydrases are common and are among the fastest enzymes, but they are not robust enough to withstand the harsh environment found in the power plant exhaust steams. In this project, Codexis will be using proprietary technology to improve the enzymes' ability to withstand high temperatures and large swings in chemical composition.