Highly efficient and stable calcium looping based pre-combustion CO2 capture for high-purity H2 production

Economically-viable CO2 capture is the most significant challenge for producing high-purity H-2 from fossil fuels. In this work, calcium looping (CaL) is explored as a low-cost, pre-combustion CO2 capture scheme for modifying fuel gas produced by gasification and water-gas shifting. The efficiency reveals that average sorption capacities as high as 401 mg-CO2/g-CaO are achieved. Extremely high CO2 removal rates and high-purity H-2 streams approaching 100% are achieved due to the uniquely high CO2 selectivity of the CaL-based CO2 capture technology. By using optimal sorption and desorption temperatures, the CaL technology also demonstrated an exceptionally high CO2 carrying capacity of 51%, and the stability of the sorbent through 20 CO2 sorption-desorption cycles in this work is 2 and 3 times better than the best and second best state-of-the-art CaO sorbents, respectively. The implications of the present results are that the CaL technology discussed here could lead to a significant decrease in energy consumption associated with CO2 capture. (C) 2019 Elsevier Ltd. All rights reserved.