It has been proposed in literature that membrane contactors may be able to replace packed columns because of their superior mass transfer performance. This chapter presents a study that examines the chemical absorption of CO2 using packed columns and membrane contactors. In this study, the performance of traditional packed columns and membrane contactors was evaluated using the overall mass transfer coefficient as the basis of comparison. The study used structured packing because it has been shown to be superior to random packing. Furthermore, performance comparisons between the two devices were done when operating conditions in the packed column and membrane absorber were identical. This allowed for a more accurate performance comparison and led to a greater confidence in the results. Results found that the membrane contactor produced higher overall mass transfer coefficient values than the packed column. This result indicates that it may be possible to develop smaller, cheaper membrane-based absorption systems.