Design, modeling, and optimization of a lightweight MeOH-to-H2 processor

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.