Coal fired power plants are the major emitters of carbon dioxide, a significant greenhouse gas. Presently, technology is available to capture the carbon dioxide from the flue gas streams, but it is costly and highly energy consuming. In order to make CCS technology economically and technologically feasible, researchers and organizations across the globe are working towards finding an efficient process that address the aforesaid problems.
Codexis is one such company that has made significant progress towards developing economical, commercial scale technology to reduce carbon emissions from the coal-fired power plants. The president and CEO of Codexis says, “Current carbon capture technology is inefficient and costly, hindering large scale development. It can nearly double the cost of electricity produced and decrease the amount of total plant electricity output.”
Codexis has developed custom enzymes that it claims reduces the energy requirement for carbon dioxide capture. Enzymes developed by the Codexis under the grant have shown to be functional and stable in relatively inexpensive and energy efficient solvents for 24 hours at temperatures up to 750C. use of these enzymes along with solvents in the carbon capture process reduces the energy requirement by nearly 30%.
These reductions are possible through development of customized carbonic anhydrase (CA) enzymes, or biocatalysts. CA is an enzyme which catalyzes the transfer of carbon dioxide in nature – for example, CA enables carbon dioxide to be released from blood into the lungs during respiration. However, the natural enzyme does not function at the high temperatures and harsh industrial conditions in coal-fired power plant flue gas. Enzyme performance has been improved by about 100,000 times over natural forms of the CA enzyme.
Codexis has developed this technology jointly with CO2 Solution Inc., Quebec, Canada.