Comprehensive Experimental Investigation of Rosehip ( Rosa canina L.) Seed Oil as a Novel Biodiesel Feedstock: Engine Performance, Combustion, Emission, and Exergy Analyses

ABSTRACT

Given the increasing volatility of global energy markets, identifying previously unexplored resources like rosehip ( Rosa Canina L.) is essential to diversify and strengthen the sustainable biodiesel feedstock portfolio. In this study, rosehip seed oil methyl ester (RSOME) was produced via transesterification at 50°C for 60 min using a 6:1 methanol‐to‐oil molar ratio and 1 wt.% KOH catalyst, achieving a biodiesel yield of 93.63%, and was experimentally evaluated in a four‐cylinder common‐rail CI engine over an engine speed range of 1500–3000 rpm under fixed‐load conditions. Combustion, performance, exergy, and emission characteristics were evaluated. RSOME exhibited a cetane number of 52.36. Among the tested fuels, B5 achieved the best overall performance, improving BSFC by 1.2%–5.5%, increasing exergetic efficiency by 1.6%–5.9%, and reducing exergy destruction by 1.3%–8.5% relative to diesel. B5 also exhibited speed‐dependent combustion behavior, slightly decreasing Pmax (up to 2.6%) at lower speeds but increasing it by 6.0% while reducing NO _x emissions by 6.8% at 3000 rpm. However, the large‐scale utilization of RSOME as a biodiesel feedstock may be constrained by the use of rosehip seed oil in high‐value health and cosmetic applications. Future studies should investigate RSOME under varying load conditions and long‐term engine durability scenarios.