The combination of advances in Computational Fluid Dynamics (CFD) reactive flow predictions together with mature, robust optimization techniques provides the opportunity to evolve promising design development methods. A quench conversion reactor concept has been chosen to perform a CFD-based multi-objective optimization on the basis of an optimization concept for turbulent, reactive flows using a Multi-Objective Genetic Algorithm (MOGA-II). The study includes the pre-optimization of the numerical setup as well as the reduction of a detailed chemical mechanism to reduce computation time and also fit the specific quench concept syngas and reaction conditions. Geometric and process parameters have been defined as control parameters to maximize the H-2/CO ratio in the syngas and minimize the corresponding exit temperature. To achieve this, three cases with different optimization strategies, including a Pareto optimization, are investigated and discussed. Optimized, feasible design options for the quench reactor were obtained. (C) 2016 Elsevier B.V. All rights reserved.