Installation of baffles in bioreactor is a promising method to improve the gas-liquid mass transfer. This work aims to understand the effect of arc baffle ('n' and 'u' shape) on gas-liquid mass transfer in flat-plate bubble column. Based on the numerical approach, the effects of three parameters of arc baffles on the CO2 gas-liquid mass transfer were studied, i.e., the projection length of baffle (L = 40, 60, 80 mm), the curvature radius of baffle (R = 50, 70, 90 mm and horizontal baffle means R = infinity mm) and the bottom clearance (H = 50, 100, 150, 200, 250, 300 mm). The mass transfer model was validated, the experimental and numerical results are in good agreement at gas flow rate of 1 to 3 L min-1. The results indicated that the overall volumetric mass transfer coefficient (KLa) for the 'n' and 'u' shape baffles both increased with the increasing L and H. For the 'u' shape baffle, the effect of R on K(L)a is low. Whereas, for the 'n' shape baffle, the K(L)a increased with the decreasing R. In addition, the results showed that the K(L)a of flat-plate bubble column with the 'n' shape baffle (L = 80 mm, R = 50 mm) can be increased by 44.5-170% compared with that with the horizontal baffle. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.