STEP carbon capture - The barium advantage

We have recently introduced the theory of the Solar Thermal Electrochemical-Process for carbon capture and utilization (STEP carbon). We have also provided experimental validation of that theory using electrolysis of molten lithium and eutectic alkali carbonates at high (similar to 50%) solar efficiency and high rate, and delineated the materials required to use STEP carbon to decrease atmospheric CO2 to preindustrial levels in ten years. In this communication an effective, alternative STEP carbon electrolyte is introduced. It is demonstrated thermodynamically that barium carbonate can provide more than an order of magnitude greater affinity for direct carbon dioxide absorption from the air than our prior lithium carbonate electrolyte. It is demonstrated experimentally that molten barium carbonate mixtures provide an effective medium for the direct electrolytic reduction of absorbed carbon dioxide at high rate and lower energy. The products of the electrolysis are graphite, which is readily stored as a valued added commodity for future generations, and oxygen. The electrolyte is not consumed in this carbon dioxide splitting process. (C) 2013 Elsevier Ltd. All rights reserved.