Effect of pH-controlled synthesis on the physical properties and intermediate-temperature CO2 sorption behaviors of K–Mg double salt-based sorbents

Combined Capture and Utilization of CO2 for Syngas Production over Dual-Function Materials

“…It has previously been shown that the mechanism of CO 2 adsorption over double salt adsorbents is through production of double carbonates. 12,20,24 Thus, a similar mechanism to the parent double salts is proposed for the corresponding DFMs.…”

“…Rapid adsorption–desorption is crucial for reducing the cycle time and hence maximizing the throughput of the combined capture-reaction system. It has previously been shown that the mechanism of CO 2 adsorption over double salt adsorbents is through production of double carbonates. ,, Thus, a similar mechanism to the parent double salts is proposed for the corresponding DFMs.…”

“…Potassium- and sodium-based CaO (K–Ca and Na–Ca) and potassium- and sodium-based MgO (K–Mg and Na–Mg) were all synthesized following the recipes reported in our earlier work or from the literature using potassium carbonate, sodium carbonate, magnesium nitrate hexahydrate, and calcium nitrate tetrahydrate precursors. ,, To synthesize DFMs, double salts were first incorporated into the γ-Al 2 O 3 using a wet impregnation method. Briefly, desired amounts of double salts were dissolved in distilled water followed by the addition of γ-Al 2 O 3 .…”

“…In this investigation, we aimed at developing DFMs that could be used for combined CO 2 capture and conversion to syngas through the DER route in one reactor and under isothermal conditions. In particular, several double salts (i.e., K–Ca, Na–Ca, K–Mg, and Na–Mg) were used as the adsorbent component of DFMs due to their high adsorption capacity at medium to high temperatures, relative stability, and rapid adsorption–desorption kinetics. − Nickel (Ni) was used as the catalyst component owing to its high catalytic activity, abundance, and low cost . Both components were supported on a high surface area γ-Al 2 O 3 .…”

CO2 capture using solid sorbents: Fundamental aspects, mechanistic insights and recent advances

“…Na2Ca(CO3)2 or K2Ca(CO3)2) [319]-[321]. The very fast formation of such Na/K-Ca carbonates (the double salts or double carbonates) appears to depend on surface area to a much lesser extent than does the formation of CaCO3 from CaO.Double carbonates have similar melting temperatures as the single alkali metal carbonates, butpossess different thermodynamic properties: in a N2 atmosphere, they decompose to CaO and the single alkali metal carbonate at temperatures similar to, or even lower than, CaCO3, whereas in a CO2 atmosphere, they do not decompose even when they reach their melting point (in contrast to many Mg-based double carbonates[322]-[325]). Double carbonates have therefore been used as sorbents for CO2 achieving higher cyclic CO2 uptake capacities than those that were observed for the reference CaO sorbent even at lower sorption temperatures[321],[326];the regeneration of the sorbents was always performed under N2.…”