Carbon dioxide (CO 2) is a major greenhouse gas that results in the climate change. Hence, efforts are in place to control CO 2 emissions into the atmosphere. CO 2 removal is also an essential step in many industrial processing operations such as coal gasification, natural gas processing and hydrogen manufacturing. Thus far, absorption is the widely used process in industrial for capturing CO 2. This paper presents a review on the factors affecting the absorption efficiency for CO 2 capture in packed column. Challenges related to the absorption efficiency improvement and the impacts to real application as well as future directions are highlighted. © 2012 The Korean Society of Industrial and Engineering Chemistry.