In the present work, an average membrane wetting ratio at high operating pressure of hollow fiber polyvinylidenefluoride (PVDF) and polytetrafluoroethylene (PTFE) membrane contactors was estimated analytically based on log-normal distribution function. The membrane characteristics, liquid velocity, operating pressure were also considered for the calculation. The simulations were validated with experimental data to confirm the accuracy of the calculated average membrane wetting at high pressure. At the operating pressure of 1 bar, dry modes are observed for both PVDF and PTFE. While the results of PTFE correspond with the dry mode, the partially wetted mode well predicts the results of PVDF at high operating pressure. The increases of liquid velocity and operating pressure show the higher membrane wetting due to the influences of increasing pressure drop in membrane module and lower surface tension of CO2-dissolved water at high operating pressure. Moreover, PTFE provides lower average membrane wetting compared with PVDF since the average membrane wetting ratio from the calculation occurs at higher trans membrane pressure at the outlet liquid (>lbar) which can be possible to maintain the dry mode including during the start-up of the process for the highest absorption performance using PTFE. (C) 2017 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.