Transesterification of Soybean Acid Oil with Al2O3 Catalyst: Effects of Catalyst Concentration and Reaction Time on Biodiesel Yield and Quality

Abstract

Environmental concerns such as increased global warming have encouraged the use of biofuels in industrial settings. This paper studies the effect of varying catalyst concentration and reaction time in biodiesel production from soybean acid oil, a by-product of the acid degumming process in soybean oil refining via alumina-catalyzed transesterification. The results from transesterification revealed a progressive increase in biodiesel yield with increase in both reaction time and catalyst concentration. Fuel properties such as cetane number, antiknock index, density and acid number of four biodiesel samples obtained with ≥ 90% yield were determined. The best fuel properties of 52.80 cetane number, 95.20 research octane number and 90.20 anti-knock index were observed for the biodiesel sample produced in 75 minutes using 5wt% Al₂O₃, with an overall free fatty conversion of 99.90%. FT-IR spectra of resultant biodiesel indicated the production of Fatty Acid Methyl Esters (FAME).