Evaluation of trimethyl borate and triethyl borate as fuel additives for enhancing physicochemical properties of canola and peanut oil biodiesels

Biodiesel is a promising alternative to conventional fossil fuels; however, its physicochemical properties often require enhancement to improve performance and stability. This study investigates the effects of trimethyl borate (TMB) and triethyl borate (TEB) as additives to improve biodiesel fuel characteristics. Canola oil and peanut oil biodiesels were synthesized using the transesterification process. Subsequently, 1% and 2% TMB and TEB were added to the biodiesels, and their physicochemical properties were analyzed. The density, kinematic viscosity, cetane number, flash point, cold flow properties, calorific value, and corrosion behavior were evaluated. The addition of TMB reduced kinematic viscosity by up to 15.7% in peanut biodiesel and 6.1% in canola biodiesel. Cold flow properties also improved, with pour point reductions of up to 2.1°C for peanut biodiesel and 1.9°C for canola biodiesel. However, slight decreases in calorific value (up to 1.7%) and flash point (up to 15°C) were observed. All samples maintained excellent corrosion resistance (1a rating). These findings demonstrate that TMB and TEB can effectively enhance biodiesel flow properties and viscosity, particularly benefiting cold climate applications.