A bibliometric analysis of studies on diesel engines fuelled with biodiesel and its blends: trends, hotspots, and future research

A bibliometric analysis of publications on biodiesel (and biodisel blend)-fuelled engine performance research (BBFEPR) was performed. Data of published works (1993-2021) were extracted using the Scopus (R) database. The network analyses of the obtained data were conducted using VOS Viewer (R) software to study the citation of journals and scientific papers, co-authorship by organization and country, and co-occurrence of author keywords involved in BBFEPR. A total of 2454 scientific articles (1797 journal articles, 508 conference papers, 130 review papers, and 19 conference review papers) were published concerning the BBFEPR. An increasing trend in publication was observed for the period under consideration. The network analysis revealed that India was the most productive country (with 1419 publications) while the most productive institution was the University of Malaya. The work published by Agarwal in 2007 (2393 citations) and the journal Fuel (11,610 citations) have the highest number of citations. Authors used 'biodiesel' followed by 'combustion', with 953 and 548 occurrences, respectively, as keywords. Research hotspots focused on biodiesel additives and feedstock development, combustion and performance improvement, and emission reduction strategies. Future research trends centered on the deployment of a magnetic field and nanoparticles to enhance combustion, performance, and emission characteristics; and on the use of nano-catalysts to improve biodiesel production.