Chapter 2 - Biomass utilization for sustainable biohydrogen generation

Abstract
Biohydrogen, a form of energy carrier, and its production from biomass through thermochemical and biochemical processing, represents a clean and renewable source of energy, contributing significantly to meeting global energy challenges. Biomass feedstock—in all forms of agricultural and forestry residues or organic wastes—can flexibly support applications in waste management and energy generation. Thermochemical methods, particularly gasification and pyrolysis, provide high yields of hydrogen. The biochemical processes such as anaerobic digestion and fermentation offer less expensive options that scale up more easily, with fermentation yielding up to four moles of hydrogen per mole of glucose. However, these processes are being enhanced by new-generation technologies such as supercritical water gasification (SCWG) and microbial electrolysis cells (MECs). SCWG achieves up to 60% in hydrogen concentrations, and MEC can achieve up to 90% of theoretical yields. Overall, low outputs of hydrogen, which is linked to variability in the quality of feedstocks, and high capital costs, remain major barriers. These challenges further necessitate improved pretreatment methods, process optimization, and supportive policies, which are discussed hereafter in this chapter. With increased awareness and policy inputs within circular economic models, these technologies can soon enter their commercialization stage. Considering that global food waste alone could yield between 120 to 150 billion cubic meters of biohydrogen annually, the role of biohydrogen in achieving carbon neutrality and energy security is thus paramount. Future systemic research and innovation, driven mainly by collaborative efforts, are imperative in realizing biohydrogen as one of the cornerstones of a sustainable energy future.

Author
Hamed Rahimi

DOI
https://doi.org/10.1016/B978-0-443-43970-4.00002-3

ISSN
978-0-443-43970-4

Publish Date: 3-Mar-2026