The conceptual design, modeling, and optimization of a MeOH-to-H₂ processor by an integration of a multi-tube annular membrane methanol reformer (MTAMMR) and the preheating system are presented. The annular membrane methanol reformer (AMMR) is a packed-bed reactor consisting of two concentric cylinders and its surface is covered with the Pd-Cu membranes. When the methanol steam reforming and the preferential oxidation reactions are carried out in the outer and the inner tubes, respectively, the counter-current axial flow in the annular gap can ensure the thermally self-sustaining operation. Under sufficient consideration of the effect of heat integration, three plate-fin heat exchangers (PFHEs) are taken into account in the preheating system. Through a series of optimization algorithms for maximizing the H₂ permeation rate of each AMMR and minimizing the total energy demand of the preheating system, respectively, the optimal operating conditions and specifications of MeOH-to-H₂ processor are obtained. Finally, it is successfully found that the perfect weight of the optimized MeOH-to-H₂ processor is close to the H₂ tank weight for 2016 Toyota Mirai vehicle if the PFHEs use titanium material.