A series of experiments were performed to investigate and compare the heat transfer characteristics of a catalyst bed during the Fischer−Tropsch synthesis (FTS) reaction and heating without the reaction. A Co/TiO2 catalyst was used in a relatively large internal diameter (ID) tubular reactor. In the first set of experiments, the bed was run under typical low-temperature FTS conditions, while in the second set an inert gas was fed to the bed and a heater with variable heat output was used along the center axis of the catalytic bed to generate the temperature profile. The two-dimensional (radial and axial) temperature profiles in the bed in both cases were measured for varying flow rates and reactor wall temperatures. Simple radial heat transfer models were derived for these two sets of experiments, and the effective thermal conductivity coefficients of the catalyst bed were estimated. Comparisons of the results showed that there were considerable differences between the values of the coefficients and in the shape of the temperature profiles in the reaction and nonreaction cases. This suggests that the liquid formed during the reaction may play an important role in affecting the heat transfer characteristics of the catalyst bed.