In this study, a carbon monoxide (CO) absorption column model based on the COSORB process was designed for CO separation. We presented a 1-D dynamic simulation model of the CO absorption column using gPROMS. The designed model was validated using actual data from a pilot plant for syngas separation. To illustrate the applicability of the designed model, case studies were conducted for CO separation from blast furnace gas (BFG) and Linz-Donawitz gas (LDG), which are the major by-product gases from the iron and steel industry. The simulation results showed slight difference in the final absorption ratio of CO from the gases ( >99% in all cases); however, CO absorption rate of LDG was 4 times larger than other cases because of its high CO concentration. However, the reaction rate of LDG is very high, the absorption of LDG in the column showed a pattern different from those for BFG and syngas absorption. The case studies for the operating pressure and feed temperature showed that the CO concentration [CO] in the feed gas must be higher than 0.16 kmol/m(3) to achieve 99% CO absorption.