This review covers the sustainable development of advanced improvements in CO2 capture and utilization.

No abstract

CO2 reduction is crucial if the effects of this gas on global warming are to be alleviated. We report for the first time an alkali carbonate molten salt promoted CaO‐based CO2 sorbent with CO2 capture performance superior to that of neat CaO. The influences of chemical composition, loading, and melting temperature of the (Li–Na–K)2CO3 molten salts and of the calcination and adsorption temperatures on CO2 capture were evaluated systematically. The microstructural and morphological evolution of the samples during CO2 adsorption was studied by X‐ray diffraction, scanning electron microscopy, and Fourier‐transform infrared spectroscopy analyses. The (Li–K)2CO3 molten salt coating was found not only to promote CO2 uptake but also to facilitate CO2 desorption from CaO. In particular, at low temperatures of 500 and 600 °C, the CO2 capture capacity increased significantly from 1.19 and 3.26 mmol g−1 to 6.93 and 10.38 mmol g−1, respectively. The melting point of the molten salts was also a crucial factor in the improvement of CO2 uptake. Kinetic studies based on fractal‐like models indicated that the rate coefficients for (Li–K)2CO3/CaO were approximately 3.3 to 3.8 times larger than those for neat CaO. The coating of alkali carbonate molten salts is believed to prevent the formation of a rigid CaCO3 layer on the surface of the CaO particles and to provide continuous delivery of CO32− to promote CO2 capture. During the CO2 adsorption/desorption cycling tests, (Li–K)2CO3/CaO resulted in a stable and reversible CO2 uptake of 6.0–6.3 mmol g−1, which is much higher than that of neat CaO (2.0 mmol g−1).

No abstract

No abstract

For CaO‐based high‐temperature CO2 sorbents, excellent cyclic stability is highly desired for its practical applications. Among all techniques, preparation of CaO‐based composites is one of the most widely accepted strategies, and the mixing status between CaO and the inert supporting material is crucial for its anti‐sintering property. This work provides a new strategy for preparing nanometrically dispersed MgO/CaO composites with significantly improved cyclic stability. The so called solvent/nonsolvent synthesis method can endow a simultaneous solidification of Ca and Mg and result in a nano‐meter level mixing of CaO and MgO. The optimized sorbent Mg/Ca‐0.2 retained 95.3 % (13.45 mmol g−1) of its initial capacity after 7 cycles, while the control CaAc2−CaO only retained 52.9 % (8.67 mmol g−1) of its initial capacity. The addition of MgO also increase the CO2 sorption and desorption kinetics after several cycles. We believe that this new and facile solvent/nonsolvent synthesis method is also promising for the preparation of other highly mixed metal oxides.

No abstract

Electrochemical impedance spectroscopy analyses were utilised to explore the oxygen ion conductivity of alkali metal salts promoted CaO.