Compact, low energy CO₂ management using amine solution in a packed bubble column

A novel method for removing CO₂ from gas streams is described. The carbon dioxide continuous scrubber, CDOCS, takes advantage of the intimate liquid-gas contact afforded in a packed bubble column to both absorb the CO₂ from a gas stream, and to regenerate the solution. The design relations and performance of a prototype CDOCS system using amine solution are presented. Over a 30-day trial, 20 m³/h of air was continuously scrubbed to 60-80 ppm. The CDOCS footprint is less than 0.18 m³ with power consumption around 300 W. Applications for air scrubbing include alkaline fuel cells, small scale processing, and industrial safety. A concept is proposed to sweeten biogas from dairy farm effluent for on-farm electricity generation. While industrial processes involving packed or plate trickle columns are well known for CO₂ production and sweetening, these conventional methods are complex and expensive, and do not scale down to air scrubbing or to small scale biogas production.