Biodiesel synthesis using spent FCC catalyst and CaO from a mixture of sunflower oil and oleic acid

Abstract

A physical mixture of two heterogeneous catalysts, calcium oxide (CaO) and spent fluid catalytic cracking (SFCC) catalyst, was used to produce biodiesel from a mixture of refined sunflower oil (RSFO) and 5 wt% oleic acid. The reaction was performed with a 6: 1 M ratio of methanol to oil at 65 °C and 3 wt% catalyst loading. The SFCC catalyst loading was also varied to investigate its effect on soap formation and biodiesel production. The presence of the SFCC catalyst reduced the reaction time from 14 h to 7 h to achieve conversion >99 %. It also decreased the soap formation compared with the reaction catalyzed by CaO alone. The lowest oleic acid conversion to soap (~20%) was obtained for CaO + 20 % SFCC case. Calcium diglyceroxide (CaD) was also tested as a catalyst – it further reduced the reaction time to 1 h for 99 % conversion.