Biodiesel Fuel from Animal Fat. Ancillary Studies on Transesterification of Beef Tallow

Abstract

Transesterification of beef tallow was investigated. The solubility of ethanol in beef tallow was much higher than that of methanol. At 100 °C the solubility of methanol was 19% (w/w). The solubility of ethanol in beef tallow reached 100% (w/w) at about 68 °C. For the distribution of methanol between beef tallow methyl esters (BTME) and glycerol, the percentage of total methanol in the glycerol phase was higher than that in the fatty acid methyl ester (FAME) phase in a simulated system at room temperature. At 65−80 °C, however, the percentage of total methanol in FAME (60% (w/w)) was higher than that in glycerol (40% (w/w)) in a 90:10 (w/w) blend of FAME and glycerol. This coincided with the methanol distribution in the transesterified product. The process for making beef tallow methyl esters should recover methanol using vacuum distillation, separate the ester and glycerol phases, and then wash the beef tallow methyl esters with warm water. At neutral pH, the separation of ester and glycerol and water washing was easier because it reduced emulsion formation.

Biodiesel de soja: taxa de conversão em ésteres etílicos, caracterização físico-química e consumo em gerador de energia

“…Assim, países como França, Áustria, Alemanha, Bélgica, Reino Unido, Itália, Holanda, Finlândia, Estados Unidos, Japão e Suécia vêm investindo significativamente na produção e viabilização comercial do biodiesel, através de unidades de produção com diferentes capacidades 6,13,21 e também se pode dizer que para o Brasil esta é uma tecnologia bastante adequada, devido à disponibilidade de óleo de soja e de álcool etílico derivado da cana-de-açúcar. No entanto, a comercialização do biodiesel ainda apresenta alguns gargalos tecnológicos 24 , surgindo como obstáculos para sua comercialização o preço da matéria-prima e os custos operacionais 25 . O Brasil consome cerca de 35 milhões de t/ano de óleo diesel 26 , assim, com ampliação deste mercado a economia de petróleo importado seria expressiva, podendo inclusive minimizar o déficit de nossa balança de pagamentos.…”

Biodiesel Production and Quality

“…During the transesterification of beef tallow with methanol the reaction was very slow during the first minute due to the mixing and dispersion of methanol into beef tallow. In the next five minutes, the reaction proceeded very fast (Ma et al, 1998). The production of beef tallow slowed down and reached the maximum value at about 15 min.…”

“…A small amount of soap favors the consumption of catalyst and reduces the catalytic efficiency, as well as causing an increase in viscosity, the formation of gels, and difficulty in achieving separation of glycerol. Ma et al (1998) suggested that the free fatty acid content of the refined oil should be as low as possible, below 0.5%, and Feuge & Grose (1949) also stressed the importance of oils being dry and free of free fatty acids. The use of alkali catalysts in the transesterification of used cooking oil is somewhat limited because the FFA in used cooking oil reacts with the most common alkaline catalysts (NaOH, KOH, and CH 3 ONa) and forms soap.…”

Production of biodiesel from vegetable oils

“…the maximum free fatty acid content must be at most 0.5% (Ma et al, 1998;Bradshaw and Meuly, 1944;Feuge and Grose;1949). This parameter is, nevertheless, less critical than the water content.…”