Hydrogen production through anaerobic fermentation has gained prominence among researchers as a promising ecological route, capable of combining the treatment of highly polluting waste with the generation of a clean fuel. Hydrogen is considered a strategic energy carrier for the transition and restructuring of the global energy matrix, as it is a renewable source free of carbon emissions. The present study aimed to conduct a critical and systematic review to analyze the main advances related to the use of anaerobic fermentation for hydrogen production and the importance of integration between biochemical pathways, addressing the parameters that influence its efficiency, the types of substrates and inoculum used, pretreatment conditions, the influence of optimized microbial strains on hydrogen production, types of reactors employed, and the technical, economic, environmental challenges associated with this biotechnological route, and main perspectives for future studies. Although still at an early stage, the feasibility of this technology has been demonstrated through various studies. It is observed that maximizing production is strongly linked to the precise control of operational variables, such as pH, temperature, hydraulic retention time, and the appropriate proportion of essential nutrients, especially carbon and nitrogen, which are fundamental for microbial growth and development in the system. Furthermore, the choice of substrates rich in organic matter with high carbohydrate content and the appropriate selection of inoculum, whether natural cultures or modified strains, aligned with the conditions of the fermentation process, are of great importance. The use of pretreatments also proves essential for the elimination of undesirable microorganisms, contributing to increased process efficiency. Thus, it is concluded that, despite its potential, anaerobic fermentation for hydrogen production still requires significant advances in research and large‐scale system development. With the improvement of the techniques involved, optimization of genetically modified strains, and integration of production processes, this approach can establish itself as a sustainable alternative for energy recovery from waste, contributing significantly to sustainable development through the transition to a cleaner and more resilient global energy matrix.
Santos et al. (Thu,) studied this question.