To address hydrogen storage and transport challenges, a methanol reforming hydrogen reactor featuring multi-pipe exhaust heat recovery was simulated using Fluent. Initial simulations focused on microscopic flow, heat transfer, and reaction dynamics within a catalyst particle stack. Subsequent macroscopic analyses of a comprehensive reactor model evaluated how reactant inlet velocity, molar ratio of steam to methanol vapor (S/M), exhaust temperature, and flow impact reforming performance. Findings indicate that smaller catalyst particles enhance heat transfer and reaction at the cost of increased pressure drop, with an optimal size of 4.4 mm. Methanol conversion correlates positively with S/M, exhaust temperature, and flow, but negatively with inlet velocity. Hydrogen production increases then decreases with S/M, showing positive correlation with inlet velocity, exhaust temperature, and flow. Carbon monoxide selectivity is inversely related to inlet velocity and S/M, and positively to exhaust temperature and flow.