Acquiring an effective CaO-based CO₂ sorbent and achieving selective methanation of CO₂

Abstract

We achieve selective methanation of CO2 and acquire an effective CaO-based CO2 sorbent by reduction of CO2 with a MgH2/CaH2 mixture.

Selective methanation of carbonate@carbon composite formed by the reaction of carbon dioxide with alkali metals

“…The small particles on the surface of samples may be produced nano‐sized carbon. The EDX mapping images show that there are uniformly distributed C and O elements in alkali carbonate@carbon composites (Figure 3D‐F), which is consistent with the previous reports 52 . The surface areas of Li 2 CO 3 @C, sodium carbonate (Na 2 CO 3 )@C, and potassium carbonate (K 2 CO 3 )@C composites are equal to 10.10, 3.41, and 9.52 m 2 /g, respectively (Figure S3, and Table S2 in Data S1).…”

“…The EDX mapping images show that there are uniformly distributed C and O elements in alkali carbonate@carbon composites ( Figure 3D-F), which is consistent with the previous reports. 52 The surface areas of Li 2 CO 3 @C, sodium carbonate (Na 2 CO 3 )@C, and potassium carbonate (K 2 CO 3 )@C composites are equal to 10.10, 3.41, and 9.52 m 2 /g, respectively ( Figure S3, and Table S2 in Data S1). The pore size distribution of M 2 CO 3 @C composite (M = Li, Na, K) is concentrated in the range of 15 to 25 nm ( Figure S4 in Data S1).…”

CO2 Capture at Medium to High Temperature Using Solid Oxide-Based Sorbents: Fundamental Aspects, Mechanistic Insights, and Recent Advances

“…606 The ball-milled samples were observed to enhance the rate of calcination, but smaller crystallites also sinter faster ("melting-point depression"), leading to a worse performance over multiple cycles when the regeneration is performed in a CO 2 atmosphere (Figure 18). It was concluded that overall obtaining small crystallites is beneficial, but new methods are required to modify CaO such that its nanocrystallinity is retained (e.g., through the addition of structural stabilizers, 607 as is described in detail in section 3.1.2, or regeneration steps 608 ).…”

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

“…It was concluded that overall obtaining small crystallites is beneficial, but new methods are required to modify CaO such that its nano-crystallinity is retained (e.g. through the addition of structural stabilizers [540], as is described in detail in Section 3.1.2, or regeneration steps [541]). Different to that, thermal pretreatment of CaO has often been employed to improve the cyclic stability of the sorbents [268], [282], [542]; the principal idea behind this approach is that the morphology of the sorbent and the pore network obtained upon an extended initial calcination step at high temperature are largely maintained through cycling ("hard skeleton"), similar to metamorphic rocks such as marble [543], [544].…”