Non-catalytic production of fatty acid methyl esters from degummed soybean oil and supercritical dimethyl carbonate in a tubular reactor

• Published in: The Journal of supercritical fluids 2023-07, Vol.198, p.105921, Article 105921
• Main Authors: Nunes, Ana Luiza Barrachini, Vernier, Liara Jalime, Albarello, Mariana, de Castilhos, Fernanda
• Format: Article
• Language: English
• Subjects: Acidity; Continuous reactor; Interesterification; Thermal decomposition
• ISSN: 0896-8446; 1872-8162
• DOI: 10.1016/j.supflu.2023.105921

This work aimed to investigate the continuous production of fatty acid methyl esters (FAME) from deggumed soybean oil (DSO) and dimethyl carbonate (DMC) under supercritical conditions. Response surface methodology (RSM) was used to optimize important reaction variables as temperature (258–342 °C), DMC:DSO mass ratio (0.48:1–5.52:1) and pressure (6.6–23.4 MPa) with the FAME yield as a response. It was possible to obtain a FAME yield of 90.50% at 325 °C, 17 MPa and 3 gDMC/gDSO, with the residence time of 10 min. The influence of the free fatty acids content in the raw material (1–10%) was evaluated. FFA in the oil positively contributed to the increase in the FAME yield obtained. Thermal decomposition phenomenon of esters at high temperatures was verified. A 52.04% thermal decomposition was observed at 342 °C, 3:1 DMC:DSO mass ratio, 15 MPa in 30 min. Short residence times showed promised results in most experimental conditions. [Display omitted] •FAME production from degummed soybean oil was assessed in a continuous reactor.•Optimum condition was 325 °C, 17 MPa and 3:1 DMC:DSO mass ratio with a 90.51% yield.•An increase in the acidity in the oil contributed to enhance FAME yield.•Due to thermal decomposition phenomenon, short residence times are recommended.