Abstract
In this work, a model for the absorption of carbon dioxide using 3wt% dilute aqueous ammonia solution in rotating packed bed and packed bed was developed and validated using experimental data. The model was then employed to design absorbers for different throughput rates, ranging from 0.01 to 1000ton-CO 2 -capture/day. The solvent used is 3wt% ammonia solution operating in the lean-to-rich loading range of 0.2-0.4. The results were compared to those obtained with a similar model using 30wt% monoethanolamine solution operating in the lean-to-rich loading range of 0.35-0.49. It was found that the apparent intensification effect of the rotating packed bed is more significant for ammonia than for monoethanolamine solution. This is explained by the fact that the operating loading of the monoethanolamine solution is closed to saturation and the average reaction rate is low at this end. Improving mass transfer will increase the amount of CO 2 transferred from gas to liquid resulting in an accumulation of free CO 2 , thus reducing the driving force. For the dilute ammonia process, there is still sufficient reaction rate to covert the free CO 2 because the operating lean-to-rich loading is far from saturation.