Cr/Al Oxide as Solid Acid Catalyst to Afford Babassu Biodisel

Journal of the Brazilian Chemical Society

Moura, Edmilson M.¹  Lima, Mariane G.¹  Neres, Haroldo L. S.¹  Moita Neto, Jose M.¹  Araújo, Eugênio C. E.¹  Moura, Carla V. R.¹  Lima, José R. O.¹  Embrapa Meio Norte, Teresina, Brazil¹  Oliveira, José E. de¹  Universidade Federal do Piauí, Teresina, Brazil¹  Sttolin, Ilza M.¹  Universidade Federal do Maranhão, São Luis, Brazil¹  Universidade Estadual Paulista, Araraquara, Brazil¹ 

关键词:  biodiesel;    catalyst;    babassu oil;    kinetic;    reusability;    leaching;    heterogeneity;   

DOI  :  10.5935/0103-5053.20150279

学科分类：化学（综合）

来源: SciELO

【 摘 要 】

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 ºC. 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 ºC. 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.

【 授权许可】

Unknown