Bibliometric Analysis of R-290 Refrigerant Research (2004 – 2025) : insight from a PAGER Framework

Growing global concern over climate change and environmental sustainability has increased research interest in environmentally friendly refrigerants, particularly propane (R-290), a low-GWP natural refrigerant. This study presents a comprehensive bibliometric analysis of R-290 research published between 2004 and 2025, based on data extracted from the Scopus database. The PAGER framework (Problem, Actors, Governance, Evidence, and Recommendations) is employed to synthesize insights derived from bibliometric mapping and analysis. The study examines publication trends, country and institutional contributions, author collaboration networks, and keyword co-occurrence using VOSviewer. The results indicate a substantial increase in publications after 2015, with significant contributions from China, India, and Indonesia. Keyword analysis identifies major research themes, including energy efficiency, flammability, natural refrigerants, life cycle assessment, and air conditioning applications. Despite the growing body of literature, research gaps remain in system-level integration, safety implementation, and real-time performance evaluation. This study provides strategic directions for future research to support the broader and safer adoption of R-290 in refrigeration and air conditioning systems.