The effect of elevated pressure on the hydrodynamics of a pilot-scale bubble column reactor has been studied in the non-Newtonian liquid phase. Various hydrodynamic characteristics of the bubble column reactor including the total gas holdup and its axial distribution, operating flow regime transition point, pressure fluctuation and its standard deviation have been evaluated by means of several pressure traducers along the column height. The superficial gas velocity and operating pressure varied from 1 to 35 (cm s(-1)) and 0.1 to 1.0 (MPa), respectively. It was found that the total gas holdup increases with an increase in the operating pressure. The operating flow regime transition point was shifted to higher superficial gas velocities at elevated pressures. The standard deviation of pressure fluctuations was also found to increase with operating pressure but to decrease with the elasticity of the liquid phase. A new correlation has also been developed to predict the gas holdup in bubble columns operating at elevated pressures. The new correlation was shown to be able to predict the experimental data of gas holdup within a mean absolute percentage error of 20%. (C) 2015 Elsevier B.V. All rights reserved.