In this work, the diisopropanolamine (DIPA) and 3-aminopropyItriethoxy silane (APTS) were respectively supported on the hydrated silica fume particles by the impregnation method. The influences of the sorbent preparation parameters on the structural property of sorbents were investigated. The CO2 capture capacities and the thermal stabilities of the prepared solid sorbents were evaluated using the T GA reaction apparatus. The result s showed that all the sorbents exhibited a type IV isotherm with a hysteresis loop of type H3. Due to the blocking of micropores (＜2 nm) and some mesopores (-10 nm), the specific surface areas of the sorbents were significantly reduced after DIPA or APTS was supported. The CO2 adsorption reaction was very rapid in the initial period, but the conversion leveled off after about 20 min, and the sorbent was incompletely converted for the reaction time as long as 1 hr. The DIPA/silica fume sorbent prepared at a weight ratio of 1.0/1 had a maximum CO 2 capture capicity of 1.25 mmol/g sorbent at 30°C, while only 66.6% of the DIPA utilization was achieved. The incomplete amino utilization could probably be explained by the limitations of CO2 mass transfer or absorption process. Furthermore, the multiple adsorption/desorption cycling results indicated that the solid sorbents are regenerable and their CO2 absorption process is fully reversible.
