Metal wire gauzes as catalyst supports and structured reactor internals offer a number of advantages over monolithic reactors. Structured catalytic reactors based on wire gauzes are explored in this study for the control of NOx emissions from a stationary engine fuelled with gas generated from a biomass gasification process. Simulations are performed on reactors filled with (a) wire gauzes, (b) multi-channel monoliths, and (c) a packed bed with 2 mm beads, for the NH3-SCR process using the kinetic data obtained for copper-exchanged ultra-stabilized zeolite Y catalyst (Cu-USY). The purpose of this procedure is to select the most efficient reactor internals and to assess the necessary reactor length allowing maximum conversion of NOx. These simulations show that optimum performance is obtained when the wire gauze support is employed. The results also show that when the Cu-USY catalyst (very active in SCR) is used in combination with a wire gauze structure, the combined effects of higher rates of reaction with higher rates of heat and mass transfer may significantly increase the NOx conversion. (C) 2012 Elsevier B.V. All rights reserved.