Ionic liquid and microwave irradiation synergism for efficient biodiesel synthesis from waste cooking oil

• Published in: Biofuels (London) 2023-02, Vol.14 (2), p.137-146
• Main Authors: Kavlak, Adile, Sönmez, Özgür
• Format: Article
• Language: English
• Subjects: Biodiesel; ionic liquids; microwave heating; waste cooking oil
• ISSN: 1759-7269; 1759-7277
• DOI: 10.1080/17597269.2022.2122148

Ionic liquid (IL) and microwave irradiation synergism was successfully employed in the catalytic conversion of waste cooking oil (WCO) into biodiesel: 1-butyl-3-methylimidazolium hydrogen sulfate ([Bmim]HSO 4 ) was used as an IL catalyst, and tested parameters influencing the biodiesel conversion were reaction time and reaction temperature, catalyst amount, and the methanol:oil molar ratio. A biodiesel conversion of 93.4% was achieved in a reaction time of 4 h, at a reaction temperature of 150°C, using a methanol:oil molar ratio of 28:1, and 10 wt% of [Bmim]HSO 4 . A comparison was made between conventional and microwave methods. While high conversion was achieved after 4 h with the microwave method, high conversion was achieved after 6 h with the conventional method. A kinetic study was also carried out for biodiesel conversion, and the activation energy and pre-exponential factor were found to be 73.30 kJ/mol and 1.36 × 10 7 min −1 , respectively. Finally, the properties of the produced biodiesel were assessed, and it was found to be compatible with fuel specifications based on the American Society for Testing and Materials (ASTM) D6751 standard.