This paper describes simulations that were performed with an Euler–Lagrange model that takes into account mass transfer and chemical reaction reported by Darmana et al. (2005. Detailed modelling of hydrodynamics, mass transfer and chemical reactions in a bubble column using a discrete bubble model. Chemical Engineering Science 60(12), 3383–3404). The model is used to simulate the reversible two-step reactions found in the chemisorption process of CO2 in an aqueous NaOH solution in a lab-scale pseudo-2D bubble column reactor. The computational results are compared with experimental data of bubble velocities, which were obtained with the use of particle image velocimetry. Furthermore, the influence of the mass transfer and chemical reaction on the hydrodynamics, bubble size distribution and gas hold-up is also studied and compared with the experiment. It is found that the present model is able to predict the entire reaction process. The prediction of the hydrodynamics without mass transfer is found to be accurate. The model however seems to underpredict the overall mass transfer process, which we believe, can be attributed to the inaccuracy of the mass transfer closure being used in the present study. Nevertheless, the trends of the influence of the mass transfer rate on the hydrodynamics have been successfully captured by the present model.