Room-Temperature Absorption of Carbon Dioxide on an Improved Soda Lime-Based Absorber

Soda lime beads are generally used for carbon dioxide (CO2) capturing at room temperature due to their higher absorption capacity compared to other absorbers. For this, the soda lime is synthesized using alumina as the doping material, which acts as a hardener to provide strength to the beads. The crushing load strength of the beads is an important parameter of the CO2 absorber material for the ease of handling and to prevent dust formation. In the present work, an improved soda lime based absorbent has been developed by the addition of silicon dioxide in the raw material to produce calcium silicate, which provides more crushing load strength to the improved soda lime beads. The effect of the addition of silicon dioxide in the raw material on the soda lime bead crushing strength and CO2 absorption capacity was studied. It was found that the crushing load strength of the beads as well as the CO2 adsorption capacity of the beads increased with increase in the addition of silicon dioxide. From a dynamic performance study, it was found that the CO2 absorption capacity of a soda lime-based pebble bed increased with increase in the flowrate of CO2 containing air due to the decrease in channeling formation of gas, which occurs at lower flowrates.