Artículos de revistas
Cr/Al oxide as solid acid catalyst to afford Babassu biodisel
Fecha
2016-03-01Registro en:
Journal of the Brazilian Chemical Society, v. 27, n. 3, p. 515-525, 2016.
1678-4790
0103-5053
10.5935/0103-5053.20150279
S0103-50532016000300515
2-s2.0-84960327382
S0103-50532016000300515.pdf
Autor
Universidade Federal do Piauí-UFPI
Universidade Estadual Paulista (Unesp)
Universidade Federal do Maranhão
Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Institución
Resumen
In this work, it was described the preparation and the characterization of a solid acid catalyst obtained by the mixture of Cr/Al oxides (CRAL). The catalyst was tested in the transesterification reaction of babassu oil with 5% of free fatty acid (FFA). The results of textural and acidity characteristics of CRAL were: area (56 m2 g-1), pore size (7.0 μm), total acidity (182.28 μmol g-1), wherein Brönsted sites are the most active. Powder X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) show three phases of the catalyst (Cr2O3/Na2Cr2O3/Al2O3), 0.25:0.25:0.50, respectively. The reaction reached conversion about 98.6% under the conditions: alcohol/oil molar ratio (24:1), catalyst to oil mass ratio of 3.0%, 15 h and 70 °C. The turnover frequency (TOF) found was 24.5 × 10-4 s-1. Kinetic of the reaction was researched over a temperature range of 60-80 °C. A pseudo first-order model was proposed with the activation energy (Ea) of 49.18 kJ mol-1. CRAL is active in the biodiesel production for just one cycle, because in the second one it loses its activity. The leaching of catalyst is about 13%, demonstrating that the catalyst is not totally heterogeneous.