The volumetricmass transfer coefficient

k

L

a

of gases (H

2

CO

CO

2

) 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 increasedwith 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

CO

2

) in the gas-paraffin-quartz system in a bubble column under elevated

temperature and elevated pressure.