Experiments are performed in a bubble column using refractive fiber optic sensors and a paraffinic oil. A temperature range of 100-175 degrees C is considered for the study. A two-dimensional fluid recirculation model is applied and this allows the successfully representation of the experimental bubble rise velocity in the bottom section of the column and the confirmation that in the peripheral region of the column, there is important gas recirculation. Valuable insights concerning the turbulent kinematic viscosity, a key model parameter, are reported. Other important effects such as the influence of temperature, gas superficial velocity and axial position on the turbulent kinematic viscosity are also described.