Improved carbon dioxide capture using metal reinforced hydrotalcite under wet conditions

The removal and recovery of carbon dioxide at high temperature using different hydrotalcite (HT) materials can be enhanced significantly under wet condition. The heat of adsorption for all the three HT samples was higher under wet condition than dry condition. The breakthrough capacity of the gas measured at 300 °C was the highest when the amount of water vapor was in the range of 25–27.5%, 27.5–30% and 30–32.5% (v/v) for carbon dioxide concentration in the feed maintained at 10%, 20% and 30% (v/v), respectively. Higher concentration of water vapor than these threshold amounts reduced the overall removal and recovery at all adsorbate concentration. We found that the adsorbent could be reused for multiple times with relatively small loss of activity under wet condition. The measured loss of capacity was only 6.7% after 50 cycles of operation.