Synthesis of calcium-based, Al2O3-stabilized sorbents for CO2 capture using a co-precipitation technique

摘要

Co-precipitation was employed to synthesize Ca-based, Al2O3-stabilized sorbents for CO2 capture. The chemical composition and morphology of the sorbents were characterized using scanning electron microscopy, X-ray diffraction and N-2 adsorption analysis. The cyclic CO2 uptake of the materials synthesized was studied in a thermo-gravimetric analyzer and compared to limestone. It was found that the calcium precursor and precipitation agent strongly influenced the chemical composition and morphology of the precipitated sorbents and, in turn, their cyclic CO2 uptake capabilities. The sorbent which was synthesized using Ca(NO3)(2) as the calcium precursor, and precipitated with (NH4)(2)CO3 at pH 9.7 showed the best cyclic CO2 uptake capability, viz. 0.36 g CO2/g sorbent after 30 cycles of calcination and carbonation, a value which compares favorably to the CO2 uptake of limestone of 0.20 g CO2/g sorbent