This electrochemical cell sequesters CO2 and generates electricity
By Gerald Ondrey |
Researchers from Cornell University (Ithaca, N.Y.; www.cornell.edu) have developed an oxygen-assisted, Al/CO2 electrochemical cell that converts CO2 into a useful product while producing electricity. This represents a possible paradigm shift from most current carbon-capture models, says Lynden Archer, the James A. Friend Family Distinguished Professor of Engineering. Traditional carbon-capture methods, such as scrubbing CO2 from fluegas with amines or other solvents, require energy to regenerate the absorbent — as much as 25% of the energy output of the power plant, says Archer.
The laboratory-scale cell (diagram) is based on a room-temperature ionic-liquid electrolyte — 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl)/aluminum chloride (AlCl3) melt, as an alternative to alkaline and saline electrolytes, which suffer from parasitic corrosion and hydrogen evolution problems. Aluminum is used as the anode and a mixed stream of CO2 and O2 is the active ingredient of the porous-carbon cathode. This cell design effectively captures CO2, converts it to a C2 oxalate (without the need for a catalyst or high temperatures), and generates 13,000 mA.h per gram of porous carbon at a discharge potential of around 1.4 V. The energy produced by…