Renewable energy integrated pyrolysis/gasification technologies for hydrogen generation: A bibliometric analysis of decarbonisation strategies for sustainable future

The growing concerns over climate change, environmental degradation, and the depletion of fossil fuel reserves have intensified the global push toward sustainable and clean energy solutions. Hydrogen has emerged as a promising alternative fuel due to its high energy content and zero-emission characteristics. Among various hydrogen production methods, biomass-based thermochemical conversion processes such as pyrolysis and gasification have been given special attention for their ability to convert renewable and waste biomass into hydrogen. This review provides a comprehensive Bibliometric and qualitative analysis of global research trends in biomass-to-hydrogen production from 2010 to 2024. A total of 5,402 publications were retrieved from the Scopus database using selected keywords including “hydrogen production,” “biomass-to-hydrogen,” and “thermochemical conversion.” Analytical tools like VOSviewer and Microsoft Excel were employed to evaluate document types, leading authors, journals, institutions, and keyword co-occurrence. The results indicate that China, USA, and India are the leading contributors to this field, with the International Journal of Hydrogen Energy being the most prominent journal. The study also reviews recent technological developments, challenges, and innovations in biomass pyrolysis and gasification for hydrogen production, focusing on process efficiency, feedstock utilization, and renewable system integration. Despite notable advancements, further research is required to enhance economic viability and scalability.