• Soda lime scrubbing technique for capturing CO2 developed at Oak Ridge National Laboratory

    Date posted:

    • Post Author

      Patrick Lavery

      Combustion Industry News Editor

New research at Oak Ridge National Laboratory in Tennessee, USA, has produced a means of scrubbing CO2 from coal-fired power plant flue gases using soda lime. Flue gases are bubbled through a solution of bis-iminoguanidines, which bind to bicarbonate anions, which then act as sorbents for CO2 molecules, in a process which the researchers say is 24% less energy intensive than industrial benchmarks. The CO2 sorption process creates a kind of organic (solid) limestone, which is separated out of the process and heated to 120oC, releasing the CO2 again in a pure form so that it can be stored. The big advantage of the process is that, after ten cycles, no absorbent is lost, a significant improvement on processes to date. Senior author of the research paper (published in Chem on 31 January), Radu Custelcean, said the “main advantage of our ‘organic soda lime’ is that it can be regenerated at much lower temperatures and with significantly less energy consumption compared to inorganic scrubbers.”