Gas-phase chlorination of methyl chloride is an important industrial process producing widely applied chlorinated derivatives. Control over reactor stability and product distribution necessitates a thorough study of the strongly coupled turbulent flow and reaction processes in chlorination reactors. In this work, a hybrid finite-volume (FV)/transported probability density function (PDF) method is employed to analyze the performance of a coaxial jet-stirred rector with three feed-stream configurations when it is scaled up from lab scale to pilot scale, and then to plant scale. The reduced mechanism used here has 21 reactions and 15 species. With premixed inlets, the pilot-scale reactor is prone to extinguish. Strategies based on turbulence-chemistry interaction analysis for ensuing reactor stability are proposed and confirmed by simulations. On the other hand, nonpremixed inlets maintain reaction in the scaled-up reactors, but produce poor product yields. (C) 2004 Elsevier Ltd. All rights reserved.