Biomass-to-hydrogen: A review of main routes production, processes evaluation and techno-economical assessment

Hydrogen is viewed as a sustainable strategic alternative to fossil fuels, especially in the field of road and air transport. Currently, hydrogen production is derived from fossil fuels or is manufactured by splitting water. A novel option, H2-generation from lignocellulosic biomass, based on renewable resources is currently in a pilot-scale demonstration or at a commercial stage. The present study reviews the thermochemical, biological, and electrochemical approaches used for biomass-to-hydrogen. The advantages, limitations, and major improvements of each process are presented. A techno-economic assessment is also established based on the production cost, technology readiness level, and industrial scalability. The objective is to allow industrial producers to visualise the degree of technological maturity of each option, clarify the necessary development efforts before reaching the commercial stage, determine the most relevant and competitive routes, and assess the suitability of biomass as a feedstock for renewable hydrogen production. In the reviewed results, the thermochemical process, particularly gasification, partial oxidation, and steam reforming, presented the best yield for H2 production. Steam gasification is the best compromise because it is suitable for wet and dry biomass, and it does not require an oxidising agent. As for biological conversion, dark fermentation is more worthwhile than photo-fermentation due to its lower energy consumption. Additionally, the electrochemical process is feasible for biomass. The findings of this study indicate that biomass-hydrogen-based processes are promising options that contribute to the H2 production capacity but require improvements to produce larger competitive volumes.