Flow effects on the kinetics of an isothermal, equimolar, second-order reaction taking place in a channel were investigated using a Lagrangian numerical method. The reactants were released instantaneously from the two opposite walls of the channel into fully developed turbulent or laminar flow. The overall conversion, the residence time and reactor length required to achieve 80% conversion, and the effective reaction rate coefficient were calculated. A correlation of the efficiency ratio, defined as the effective rate coefficient divided by the reaction rate constant, with the flow parameters was found. (C) 2007 Elsevier B.V. All rights reserved.