• Bibliometric analysis reveals two decades of biogas research trends in Africa. • South Africa demonstrates leadership in biogas research output, funding, and regional collaborations. • Five key thematic clusters have been identified: technology, policy, waste, agriculture, and socio-economics. • Limited private-sector involvement indicates untapped investment opportunities. • Future research should prioritize scalable technologies and co-digestion strategies. The need to switch to more sustainable energy sources is a critical priority for Africa, where there is an established case of energy poverty, waste management challenges, and environmental degradation persist. Despite the vast potential of anaerobic digestion (AD) for biogas production, fragmented research output and the absence of a systematic regional synthesis limit its translation into practical solutions. This work seeks to address this gap by presenting a comprehensive bibliometric analysis of two decades of research on anaerobic digestion as a sustainable route for biogas production from organic waste in Africa. The data used was retrieved from the Scopus database and covers a 20-year period (2004–2024), and was analyzed using VOSviewer software. Using these bibliometric tools, 156 peer-reviewed publications were analyzed to elucidate key research trends, thematic clusters, author collaborations, funding patterns, and emerging research priorities. The findings reveal that South Africa leads the region in biogas research output, funding contributions, and institutional collaborations, underscoring its pivotal role in advancing biogas technology. Five distinct thematic clusters were identified, encompassing technical aspects of anaerobic digestion, waste management strategies, agricultural integration, energy policy, and socioeconomic dimensions. Although significant advancements have been made, issue like high initial costs, inadequate ineffective policies, and limited private sector participation continue to impede large-scale adoption. Funding analysis highlights the predominance of government agencies, academic institutions, and international collaborations, with a notable deficit in private sector investment. This study emphasizes the importance of multidisciplinary approaches, increased financial support, and targeted policy interventions to address existing gaps and drive innovation. Future research should focus on optimizing co-digestion strategies, enhancing biogas yields, and developing scalable technologies tailored to local conditions. This bibliometric analysis provides valuable insights for researchers, policymakers, and stakeholders, and suggests a roadmap for future research and practical implementation of biogas as a sustainable energy source to address Africa’s energy and environmental challenges.
Amenaghawon et al. (Sun,) studied this question.