The main idea of this research is the modification of methane tri-reforming reactor to increase syngas production capacity. Since methane tri-reforming is an integration of steam reforming, dry reforming, and partial oxidation, the feeding policy is a key solution to shift reaction network toward the desired condition. In this regard, the conventional fixed bed reactor is divided into three equal beds in series, and the optimal distribution of steam, carbon dioxide and oxygen between beds is calculated to maximize hydrogen production. The conventional and proposed configurations are heterogeneously modeled based on the mass and energy conservation laws at steady state condition. Then, the accuracy of the developed model and considered assumptions is proved. To calculate the optimal condition of the proposed multi-bed tri-reformer, a single objective optimization problem is formulated considering process limitations. Based on the optimization results steam and carbon dioxide injection between beds increases hydrogen production about 2.93% at the same catalyst loading. The main advantages of the proposed configuration are higher hydrogen production, adequate hydrogen to carbon monoxide ratio, and higher carbon dioxide conversion. The results shows that carbon dioxide conversion in the proposed multi-bed configuration is about 16%. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.