Bibliometric analysis and road-mapping on hydrogen production from biomass-derived glycerol

The multifaceted challenges associated with the current energy insecurity, alongside the significant repercussions of fossil fuel consumption, particularly the emission of greenhouse gases (GHG), warrant the necessity for adopting renewably-derived fuels. However, the quest for promoting a circular economy has led to the exploration of waste glycerol as a viable hydrogen (H₂) production feedstock. This strategy of converting waste glycerol into H₂ expands energy source diversification's sustainability and enhances biodiesel production's economic and environmental performance. Therefore, this study provides valuable insights into the current state and future trajectory of the glycerol-based pathway for H₂ production via reforming processes using bibliometric analysis and road-mapping approach. A total of 500 documents comprising 384 articles, 36 reviews, 59 conference papers, and 21 other encyclopedia entries, published in the last two decades (2004–2024) were extracted from the Scopus database. The analysis shows a relatively low publication output in the years before 2010, gradually reaching a peak of 45 publications in 2020. The numbers fluctuated in subsequent years, possibly due to the impact of the COVID-19 pandemic. A resurgence in 2022, with 40 publications, was observed, reflecting sustained interest in the research field driven by the growing adoption of renewable energy. As a result, the combined effect of bibliometric analysis and road-mapping approach identifies knowledge gaps, discovers emerging trends, assesses the research impact, and visualizes the intellectual structure of the research field, thereby paving the way for future collaboration and decision-making with the support of techno-economic and lifecycle assessment (LCA) of the biomass-based glycerol H₂ production.