Study of the calcination of CaCO3 by means of a Cu/CuO chemical loop using methane as fuel gas

The Ca-Cu looping process allows a H-2-rich product gas to be obtained on the basis of the sorption enhanced reforming (SER) concept, while generating a concentrated stream of CO2 suitable for geological storage or industrial use. Previous works have demonstrated that the Cu/CuO chemical loop provides a feasible alternative for regenerating the CO2-sorbent required for the SER with potentially low energy penalties. In this work, the CuO reduction/CaCO3 calcination operation, which is the key stage of the Ca-Cu looping process, is experimentally demonstrated in a fixed-bed reactor at TRL4 using pure methane as fuel gas. The effect of the temperature of the solids bed on the operation is also evaluated. A detailed characterization of both CuO- and CaO-based materials resulting from the experiments has been carried out, revealing only minor changes in their textural properties, which demonstrates their high stability after successive oxidation-carbonation-reduction/calcination cycles.