Modified Dolomite-Based Pellets for High Temperature Post-Combustion Co2 Capture

Abstract

In this study, synthetic dolomite-based pellets were prepared by means of one-pot method. Zr and Ce were used as modifier and aluminate cement was employed as binder. The addition of the promoters by two different routes (1-step or 2-step) was analyzed. The pellets were exposed to several carbonation-calcination cycles in a thermogravimetric analyzer at low CO2 concentration (5 vol.%) and wet conditions (8 vol.% steam) at 600 oC. The calcination was carried in harsh conditions to mimic the realistic process (950 oC, 77 vol.% CO2). The Zr-modified and synthetized by 2-step one-pot method was presented as the most promising among all the sorbents with an initial capturing capacity of 16.9.% in cycle 2 to 14.4 % after cycle 40. It was proved that both, sintering and pore blockage are fairly well prevented. Different characterization techniques were employed, including N2 adsorption-desorption at 77 K, X-ray diffraction (XRD) and scanning electron microscopy combined with energy-dispersive spectroscopy (SEM-EDS).