Transesterification of used cooking oil at ambient temperature using novel solvent: experimental investigations and optimisation by response surface methodology

Biodiesel is an apposite alternative to fossil diesel that can abate environmental and economic concerns, but its production processes are energy-intensive. In the present study, the transesterification is carried out from used cooking oil (UCO) in the presence of a novel solvent to make the reaction mixture a single-phase at ambient temperature with minimal heat and mechanical stirring. The process parameters were optimised using central composite design (CCD) in response surface methodology (RSM). The optimum parameters for the maximum biodiesel yield of 94.83% were observed with 4:1 methanol/UCO molar ratio, 0.50% catalyst amount, 11.22 mL solvent amount, 36.83 degrees C reaction temperature and 10 min reaction time. The predicted yield and FAME yield of 94.83% and 99.44% were achieved, respectively, with ANOVA analysis having R-2 = 0.9504, Adj-R-2 = 0.8957 and Pred-R-2=0.7948. Further, the properties of biodiesel were also characterised through different analytical techniques and compared with literature reports.