Elevated temperature carbon dioxide capture via reinforced metal hydrotalcite

Hydrotalcite-like compounds (HT) were synthesized following a combustion-recrystallization-impregnation procedure using aluminum, magnesium nitrates precursors and carbonate solutions. Different types and amount of fuels, different amount of carbonate and different synthesis temperature were used during HT synthesis in order to understand their roles in forming HT structure and CO2 adsorption level. It was discovered that the addition of fuels to facilitate the reaction into mixed oxides and later HT influenced the capacity of CO2 adsorption. Beside type and amount of fuels, the carbonate amount and synthesis temperature also played important roles in forming the HT structure and thus, the CO2 adsorption level. The highest adsorption capacity was observed at 1.21 mmol/g by K-Na HT (K of 18.5% and Na of 1.5%) at operating temperature of 300 degrees C and 0.4 bar of CO2 partial pressure in the presence of N-2 (equivalent to total pressure of 1.34 bar). The HT exhibited Type IV isotherm, a typical mesoporous and slit shape pore material with pore size of 5.4 angstrom and BET surface area of 124 m(2)/g. (C) 2010 Elsevier Inc. All rights reserved.