Ultrasonic versus silent methylation of vegetable oils

Abstract

The profile of fatty acid methyl esters (FAME) of different vegetable oils produced under ultrasonic irradiation and conventional heating were compared. In the presence of potassium hydroxide as catalyst, the distribution of FAME was quite similar for both procedures, while in the case of sodium hydroxide ultrasonic irradiation gave better results. The FAME profile resulted from the reaction catalyzed by sulfuric acid was almost the same with the one resulted from the reaction catalyzed by KOH, while boron trifluoride can give rise to many artifacts, thus is not a reliable catalyst.

Ultrasound-assisted Synthesis of Biodiesel from Crude Cottonseed Oil Using Response Surface Methodology

“…To obtain increased biodiesel yields within shorter reaction times, ultrasonically-assisted production of biodiesel is currently the focus of new research [6][7][8][9] . This process improve the mass transfer between two immiscible liquids, methanol and oils through cavitation, the phenomenon in which bubbles containing primary vapor reduce the ambient pressure sufficiently at essentially constant temperatures, causing an explosive vaporization into the cavities.…”

Contribución al estudio de la aplicación de ultrasonidos de potencia en el secado convectivo de alimentos

“…Las principales aplicaciones de los ultrasonidos de potencia en medios líquidos se encuentran en el salado de carne (Cárcel, 2003) y queso (Sánchez et al, 2000), la deshidratación osmótica de frutas (Taiwo et al, 2003) y también en procesos de extracción de productos naturales tanto con disolventes convencionales (Romdhame y Gourdon, 2002;Albu et al, 2004;Stavarache et al, 2006) como con fluidos supercríticos (Riera et al, 2004;Balachandran et al, 2006;Hu et al, 2006;Cho et al, 2006). A partir del estudio de dichos trabajos se han podido identificar algunas de las principales variables que influyen en la aplicación de ultrasonidos de potencia: intensidad acústica, frecuencia, temperatura y tipo de material.…”

Physical Properties and Combustion Characteristics of Emulsion Fuels of Water/Diesel Fuel and Water/Diesel Fuel/Vegetable Oil Prepared by Ultrasonication

“…The physical effects arising from acoustic streaming, high-speed microjets, microstreaming and shockwaves can contribute to more effective preparation of O/W (oil-in-water) or W/O (water-in-oil) emulsions. Several researchers have investigated the preparation of emulsions 11) 16) and synthesis of biodiesel fuel by ultrasonic methods 17), 18) . This study investigated the application of the ultrasonic technique to preparation of two-phase water-indiesel fuel/vegetable oil emulsion fuels for use in burner combustion systems.…”