A new strategy for the control application to enhance the CO2 absorption efficiency of the bench-scale bubble column reactor by combining the pH target optimizer with an I/O linearizing controller is presented. A lumped parameter approach using two-film theory is introduced to develop the reactor model. The target pH set point is obtained by solving an optimization problem to maximize the absorption efficiency based on the steady state reactor model, while the I/O linearizing controller enforces the pH to track the target. Real-time control performance of the proposed method with a bench-scale bubble column reactor is investigated. The experimental results show that the I/O linearizing controller successfully enforces the reactor pH with less fluctuation in control action compared with a PI controller. The pH target optimizer provides the optimal use of the sodium hydroxide flow to enhance the CO2 removal efficiency in the reactor.