A considerable interest has been expressed in using slurry bubble column reactors (SBCRs) to carry out FT synthesis, particularly for the conversion of stranded natural gas into liquids. Historically, wall effects in small-scale SBCR reactors (diameters less than 30 cm) have presented many challenges with regard to interpretation of kinetic/conversion data for process scale-up. In this paper, we describe a novel 5 cm diameter SBCR system that incorporates a natural slurry recirculation loop that minimizes wall effects and promotes plug-flow behavior in the liquid phase. Conversion performance, activity decline, and attrition of a precipitated Fe/K Fischer-Tropsch synthesis (FTS) catalyst in the SBCR is compared to that of a continuous stirred tank reactor (CSTR) run using the same catalyst and operating conditions. (C) 2003 Elsevier B.V. All rights reserved.