title: Influence of the calcination and carbonation conditions on the CO₂ uptake of synthetic Ca-based CO₂ sorbents.
abstract: In this work we report the development of a Ca-based, Al(2)O(3)-stabilized sorbent using a sol-gel technique. The CO(2) uptake of the synthetic materials as a function of carbonation and calcination temperature and CO(2) partial pressure was critically assessed. In addition, performing the carbonation and calcination reactions in a gas-fluidized bed allowed the attrition characteristics of the new material to be investigated. After 30 cycles of calcination and carbonation conducted in a fluidized bed, the CO(2) uptake of the best sorbent was 0.31 g CO(2)/g sorbent, which is 60% higher than that measured for Rheinkalk limestone. A detailed characterization of the morphology of the sol-gel derived material confirmed that the nanostructure of the synthetic material is responsible for its high, cyclic CO(2) uptake. The sol-gel method ensured that Ca(2+) and Al(3+) were homogenously mixed (mostly in the form of the mixed oxide mayenite). The formation of a finely and homogeneously dispersed, high Tammann temperature support stabilized the nanostructured morphology over multiple reaction cycles, whereas limestone lost its initial nanostructured morphology rapidly due to its intrinsic lack of a support component.
authors.affiliation: Laboratory of Energy Science and Engineering, ETH Zurich, Leonhardstrasse 27, 8092 Zurich, Switzerland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Broda
authors.forename: Agnieszka M
authors.initials: AM
authors.lastname: Kierzkowska
authors.forename: Christoph R
authors.initials: CR
authors.lastname: Müller
mesh_terms: D002118:Calcium / Q000737:chemistry; D002119:Calcium Carbonate / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry; D049329:Nanostructures / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D013696:Temperature; D014961:X-Ray Diffraction
chemical_list: D002254:Carbonates; D010087:Oxides; D002245:Carbon Dioxide; D002119:Calcium Carbonate; D002118:Calcium