Thermal management of highly exothermic Fischer-Tropsch synthesis (FTS) has been a challenging bottleneck limiting the radial dimension of the packed-bed (PB) reactor tube to 1.5 in. ID. A computational demonstration of a novel microfibrous entrapped cobalt catalyst (MFECC) in mitigating hot spot formation has been evaluated. Specifically, a two-dimensional (2-D) model was developed in COMSOL (R), validated with experimental data and subsequently employed to demonstrate scale-up of the FTS bed from 0.59 to 4 in. ID. Significant hot spot of 102.39 K in PB was reduced to 9.4 K in MFECC bed under gas phase at 528.15 K and 2 MPa. Improvement in heat transfer within the MFECC bed facilitates higher productivities at low space velocities (>= 1000 h(-1)) corresponding to high CO conversion (>= 90%). Additionally, the MFECC reactor provides an eightfold increase in the reactor ID at hot spots <= 30 K with CO% conversions >= 90%. This model was developed for a typical FTS cobalt-based catalyst where CO2 production is negligible. (C) 2017 American Institute of Chemical Engineers