Oxidative coupling of methane (OCM) is suggested to be a promising process for the conversion of the abundant natural gas into useful chemicals. However, this reaction faces many drawbacks such as low yields for higher hydrocarbons, fast catalyst deactivation, and huge heat effects of the reaction. Only a well-designed fluidized bed reactor is able to overcome effectively those disadvantages and to provide a satisfactory continuous operation. However, design approaches for fluidized bed reactors are still based on models developed during 70s and 80s, which cannot take into account various hydrodynamic effects on the reactor performance. Thus, a reactor designer has usually to rely on extensive experiments in order to improve the classical fluidized bed reactor design. In this work, the relevance of hydrodynamics, reactor geometry, and feeding policy on the performance of a fluidized bed reactor for the OCM is shown. For this purpose, several case studies of fluidized bed reactors are simulated in full 3D geometry under the same reaction conditions, but with different reactor geometries and feeding policy. These studies show the significance of hydrodynamic parameters for the reactor performance, and moreover, how fluidized bed reactor performance can be improved by a careful study of coupled momentum-mass transport-reaction phenomena. Furthermore, it can be demonstrated that a suitable distributed feeding policy of oxygen provides an improved yield while a traditional fluidized bed reactor design results in an inferior performance among all investigated cases. (C) 2011 Elsevier B.V. All rights reserved.