Effects of Different Alcohol and Catalyst Usage on Biodiesel Production from Different Vegetable Oils

In this study, biodiesels were produced from sunflower, corn, soybean, rapeseed, hazelnut, and cottonseed oils by transesterification reactions using methanol, ethanol, 2-propanol, and 1-butanol as alcohol. Potassium hydroxide, sodium hydroxide, and sulfuric acid were used as catalysts. After biodiesel production, ester conversion rates and fuel properties such as viscosity, density, and total and free glycerol were determined and compared in graphical forms. From the experimental results, it was concluded that the most suitable alcohol for biodiesel production is methanol. Other alcohols should be used with an acid catalyst in long reaction times such as at least 48 h. As the alkaline catalyst, potassium hydroxide is more superior to sodium hydroxide. Among the studied vegetable oils, sunflower oil gave the best results, while cottonseed oil gave the worst ones in terms of practicality and some fuel properties.