Probing the Performance of a Ni–Ca–Ce Dual-Functional Material for Integrated CO<sub>2</sub> Capture and Utilization from a Synthetic Flue Gas Approximating Industrial Composition
Lukas C. Buelens, Louis Van de Voorde, Varun Singh, Hilde Poelman, Guy Marin, Vladimir Galvita
Abstract
Confining CO 2 emissions and accelerating toward a circular carbon economy demand process intensification strategies. This work evaluates integrated CO 2 capture and catalytic conversion over a solid dual-functional material (DFM) in the presence of H 2 O and O 2, approximating industrial compositions in a laboratory-scale fixed-bed reactor. CO 2 from flue gas and its isothermal utilization with H 2 are temporally separated by applying chemical looping with isolated steps driven by CaO and Ni. A ceria-modified DFM shows over 60% CO 2 capture efficiency and 70% CO 2 conversion with average space-time yields exceeding 850 kg CO2 m –3 reactor h –1 and 300 kg CO m –3 reactor h –1 at 973 K and 120 kPa. Increasing the H 2 feed concentration during the CO 2 utilization step steers the selectivity toward CH 4 . The material maintains its performance over 30 cycles using a synthetic flue gas containing CO 2, O 2, and H 2 O and 75 mol % H 2 for the CO 2 capture and utilization steps.