Hydrogen production via methanol steam reforming: a review of H2 production enhancement methods

• Systematic compiling and categorization of thermal enhancements in MSR presented. • Heat transfer limitations cascade into other MSR performance constraints. • Flow configuration is a promising yet under-investigated enhancement pathway. • Structured supports enhance heat transfer but face adhesion and hold-up issues. • Temperature-CO tradeoff requires axial temperature control for optimization. With the increasing shift towards sustainable energy production, storage, conversion and utilization, leveraging existing infrastructure may be crucial for a seamless transition. Hydrogen production via steam reforming remains a vital component of the energy landscape. However, the endothermic nature of the reaction still presents significant challenges, especially when scaling down the process. Methanol steam reforming has garnered attention due to several underlying benefits, but heat transfer – which has been identified as the primary limiting mechanism – remains a dominant constraint. While recent reviews have focused on catalysts, reaction mechanisms, and reactor designs with significant emphasis on microreactors, limited attention has been given to systematically compiling and analyzing the various heat transfer enhancement techniques implemented to address these thermal limitations. This review examines reactor-scale heat transfer intensification approaches across multiple domains: reactor geometry modifications, methods of heat supply, structured catalyst supports and flow disturbance techniques. Each enhancement strategy is evaluated in terms of its impact on fuel conversion, hydrogen production, temperature distribution, and pressure drop. While microreactors demonstrate superior thermal uniformity, their widespread adoption faces barriers including fabrication costs, catalyst adhesion challenges, and limited production capacity. Conversely, flow disturbance methods in conventional packed bed reactors have demonstrated capacity improvements exceeding 60% with reduced temperature gradients. This overview provides insights into mechanisms underlying each enhancement technique and identifies promising areas for future research in this well-established process, with particular emphasis on flow configuration as an under-explored pathway for intensification.