The volumetricmass transfer coefficient k(L)a of gases (H-2, CO, CO2) and mass transfer coefficient k(L) on liquid paraffin side were studied using the dynamic absorption method in slurry bubble column reactors under elevated temperature and elevated pressure. Meanwhile, gas-holdup and gas-liquid interfacial area a were obtained. The effects of temperature, pressure, superficial gas velocity and solid concentration on themass transfer coefficient were discussed. Experimental results show that the gas-liquid volumetric mass transfer coefficient k(L)a and interfacial area a increased with the increase of pressure, temperature, and superficial gas velocity, and decreased with the slurry concentration. The mass transfer coefficient k(L) increased with increasing superficial gas velocity and temperature and decreased with higher slurry concentration, while it changed slightly with pressure. According to analysis of experimental data, an empirical correlation is obtained to calculate the values of k(L)a for H-2 (CO, CO2) in the gas-paraffin-quartz system in a bubble column under elevated temperature and elevated pressure. (c) 2014 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.