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.