In order to utilize waste heat that is widely available in many industries, effects of flow and operation parameters on micro-tube reactor performance for hydrogen production through methanol steam reforming were studied by simulation. Results showed that outlet parameters are not significantly affected by the flow arrangements in both cocurrent and countercurrent flow conditions of reactant/heating media. However, the choice of aligned or crossing reactor tubes would affect methanol conversion and CO molar fraction. Methanol conversion rate and hydrogen molar fraction were higher for aligned arrangement than that of the crossing arrangement at different inlet velocities except for the inlet velocity of 0.1 m/s condition. They were also higher for aligned arrangement at different water/methanol molar ratios. CO molar fraction at reactor outlet was also examined for different tube arrangements. The results from this study can be used to optimize the design parameters for waste heat recovery coupled with methanol steam reforming reactors for hydrogen production. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.