Molten salts-modified MgO-based adsorbents for intermediate-temperature CO2 capture: A review

Carbon dioxide (CO2) capture using magnesium oxide (MgO)-based adsorbents at intermediate temperatures has been regarded as a very prospective technology for their relatively high adsorption capacity, low cost, and wide availability. During the past few years, great effort has been devoted to the fabrication of molten salts-modified MgO-based adsorbents. The extraordinary progress achieved by coating with molten salts greatly promotes the CO2 capture capacity of MgO-based adsorbents. Therefore, we feel it necessary to deliver a timely review on this type of CO2 capturing materials, which will benefit the researchers working in both academic and industrial areas. In this work, we classified the molten salts-modified MgO adsorbents into four categories: (1) homogenous molten salt-modified MgO adsorbents, (2) molten salt-modified double salts-based MgO adsorbents, (3) mixed molten salts-modified MgO adsorbents, and (4) molten salts-modified MgO-based mixed oxides adsorbents. This contribution critically reviews the recent developments in the synthetic method, adsorption capacity, reaction kinetics, promotion mechanism, operational conditions and regenerability of the molten salts-modified MgO CO2 adsorbents. The challenges and prospects in this promising field of molten salts-modified MgO CO2 adsorbents in real applications are also briefly mentioned. (C) 2017 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.