Catalytic conversion of residual raw material into biodiesel using a superior magnetic solid acid catalyst based on Zn-Fe ferrite: thermodynamic and kinetic studies

• Published in: RSC advances Vol. 14; no. 29; pp. 2743 - 2756
• Main Authors: Gonçalves, Matheus Arrais, Lima dos Santos, Hiarla Cristina, Melo da Silva, Paula Maria, Paula da Luz Corrêa, Ana, Ribeiro, Thaissa Saraiva, de Araújo Sobrinho, Izadora, Narciso da Rocha Filho, Geraldo, Vieira da Conceição, Leyvison Rafael
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 27.06.2024; The Royal Society of Chemistry
• Subjects: Biodiesel fuels; Catalysts; Catalytic converters; Chemistry; Energy consumption; Esters; Industrial applications; Magnetic properties; Molybdenum; Molybdenum oxides; Molybdenum trioxide; Raw materials; Zinc ferrites
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d4ra03580a

This study investigates the potential and applicability of a novel solid magnetic catalyst constructed by incorporating molybdenum oxide (MoO 3 ) into zinc ferrite (ZnFe 2 O 4 ) to biodiesel production using Waste Frying Oil (WFO) as the residual raw material. The molybdenum amounts (5, 15, 25, 35 and 45%) present in the catalyst were studied and the catalyst demonstrated great characteristics and high acid properties, as well as superior magnetic and catalytic attributes. The one variable at time (OVAT) optimization method revealed that the application of the MoO 3 /ZnFe 2 O 4 catalyst resulted in obtaining a biodiesel with 97.6% ± 0.727 conversion to fatty acid methyl esters (FAME) under the following optimized reaction conditions: temperature of 165 °C, methanol : WFO molar ratio of 40 : 1, catalyst amount of 6 wt% and reaction time of 3 h. In addition, the catalyst showed high reusability after six reaction cycles, with conversion to esters above 90%. Besides, the activation energy ( E a ) calculated in the kinetic study was 25.3 kJ mol −1 . Moreover, the properties of the synthesized biodiesel met the standards set by the ASTM D6751 and EN 14214, which indicates the high MoO 3 /ZnFe 2 O 4 potential for industrial application with low energy consumption as well as minimal negative environmental impact. This study investigates the potential and applicability of a new solid magnetic catalyst constructed by incorporating molybdenum oxide (MoO 3 ) into zinc ferrite (ZnFe 2 O 4 ) for the production of biodiesel using waste frying oil as the residual raw material.