title: Soybean biodiesel methyl esters, free glycerin and acid number quantification by 1H nuclear magnetic resonance spectroscopy.
abstract: Production of alternative fuels, such as biodiesel, from transesterification of vegetable oil driven by heterogeneous catalysts is a promising alternative to fossil diesel. However, achieving a successful substitution for a new renewable fuel depends on several quality parameters. (1)H NMR spectroscopy was used to determine the amount of methyl esters, free glycerin and acid number in the transesterification of soybean oil with methanol in the presence of hydrotalcite-type catalyst to produce biodiesel. Reaction parameters, such as temperature and time, were used to evaluate soybean oil methyl esters rate conversion. Temperatures of 100 to 180 °C and times of 20 to 240 min were tested on a 1 : 12 molar ratio soybean oil/methanol reaction. At 180 °C/240 min conditions, a rate of 94.5 wt% of methyl esters was obtained, where free glycerin and free fatty acids were not detected.
authors.affiliation: LCO, Laboratório de Catálise e Oleoquímica, Faculdade de Química, UFPA, Belém, Pará, Brazil. natasha.coral@yahoo.com.br
authors.forename: Natasha
authors.initials: N
authors.lastname: Coral
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Rodrigues
authors.forename: Victor
authors.initials: V
authors.lastname: Rumjanek
authors.forename: José Roberto
authors.initials: JR
authors.lastname: Zamian
authors.forename: Geraldo Narciso
authors.initials: GN
authors.lastname: da Rocha Filho
authors.forename: Carlos Emmerson Ferreira
authors.initials: CE
authors.lastname: da Costa
mesh_terms: D000143:Acids / Q000032:analysis*; D056804:Biofuels; D004952:Esters / Q000032:analysis*; D005990:Glycerol / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D013024:Soybean Oil / Q000737:chemistry*; D013025:Glycine max / Q000737:chemistry*
chemical_list: D000143:Acids; D056804:Biofuels; D004952:Esters; D013024:Soybean Oil; D005990:Glycerol