Cadmium based metal oxide sorbents for pre-combustion CO2 capture

摘要

Recent efforts in reducing carbon dioxide emissions arenmotivated by incentives to slow down anthropogenic climate change.nNevertheless, carbon dioxide emitting fossil fuels, like coal, are likelynto continue to play a key role in the power generation sector over thennear future. In order to reduce CO2 emissions while generating powernfrom fossil fuels, the Integrated Gasification Combined Cycle (IGCC)nprocess with CO2 capture (also known as pre-combustion CO2ncapture) is proposed. In this process, coal is gasified with water in anlow oxygen atmosphere to produce a synthesis gas (syngas)nconsisting of mostly water, hydrogen and carbon monoxide. In ansubsequent water gas shift reactor, this syngas reacts to form mostlynhydrogen and CO2. This shifted syngas typically has a temperature ofn250 to 400 °C.1 It would thus be beneficial to remove the CO2 in thisntemperature range without the need for further cooling or heating ofnthe syngas. The product that is left after this step would then be highnpurity hydrogen that could be used as a clean energy source in ancombined gas/steam turbine power plant, while the CO2 isnsequestered. Doiwa and Tomanek reported that cadmium oxide reactsnwith carbon dioxide at temperatures between 250 and 300 °C ifnsodium halides are present.2 Based on their observations, it wasnproposed that these materials might be suitable as sorbents in thenscope of pre-combustion CO2 capture.