Screening of inert solid supports for CaO-based sorbents for high temperature CO2 capture

Optimization of the structural characteristics of CaO and its effective stabilization yield high-capacity CO2 sorbents

“…According to our ICP-OES data, the sorbents Ca90Mg10, Ca85Mg15, and Ca80Mg20 had a MgO content of 8, 11, and 16 wt.%, respectively. These quantities of stabilizers were significantly lower than what has been used so far in most CaO-based CO 2 sorbents as reported in the literature 11 , 51 . To achieve a high CO 2 uptake capacity (on a weight basis), it is essential to minimize the quantity of the CO 2 -inactive stabilizer in the sorbent.…”

CaO‐Based CO2 Sorbents Effectively Stabilized by Metal Oxides

“…Concerning stabilizers, an additional aspect that has to be considered is the potential formation of mixed oxides with CaO (e.g.,C a 12 Al 14 O 33 with Al 2 O 3 or CaZrO 3 with ZrO 2 ), whereas some metal oxides such as MgO or Y 2 O 3 do not form any mixed oxidesw ith CaO under typical operating conditions. [5,[8][9][10][11] Turning to materials ynthesis techniques, in most of the works reported so far," conventional" approaches including mechanical mixing, wet impregnation, or co-precipitation have been used to introduce the stabilizer into the CaO matrix. [12][13][14] The main issue associated with these preparation techniques is that they do not provide materials with enhanced structural properties, such as high pore volume and surface area, which are criticalt oo btain high CO 2 uptakes.F urthermore, most conventional techniques can only provide al imited degree of homogeneity in terms of mixing between the active materiala nd the stabilizer.A saresult, larger quantities of the stabilizer are Calcium looping( i.e.,C O 2 captureb yC aO) is ap romising second-generation CO 2 capture technology.C aO, derived from naturallyo ccurring limestone, offersa ni nexpensives olution, but due to the harsh operating conditions of the process, limestone-derived sorbents undergo ar apid capacity decay induced by the sintering of CaCO 3 .H ere, we report aP echini methodt os ynthesize cyclically stable, CaO-based CO 2 sorbents with ah igh CO 2 uptake capacity.T he sorbents synthesized feature compositional homogeneity in combination with an anostructured and highly porous morphology.…”

Inorganic carbonate composites as potential high temperature CO2 sorbents with enhanced cycle stability

“…35 In another study, Luo et al found that the CO 2 uptake on MgO/CaO material was 0.15 g g À1 aer 100 cycles. 36 For a more extensive comparison of different metal oxides as inert support materials we refer the readers to Hu et al 20 It would appear that the cyclic stability of ACMO-4 and ACMO-5 was higher than that of some of the other sorbents previously studied with a high level of CO 2 uptake still possible aer 100 cycles. When compared with CaO-CaCO 3 and CaO-HPACC obtained from the calcination of CaCO 3 and HPACC, ACMOs demonstrate enhanced cyclic CO 2 uptake capacity due to the ability for MgO and Al(NO 3 ) 3 to hinder the sintering of CaCO 3 in ACMOs.…”