New heterogeneous catalyst for the esterification of fatty acid produced by surface aromatization/sulfonation of oilseed cake

FUEL

卷:150

Article

Santos, Eleonice Moreira¹  de Carvalho Teixeira, Ana Paula¹  da Silva, Flavia Gontijo¹  Cibaka, Therese Ebambi¹  Araujo, Maria Helena¹  Coelho Oliveira, Willian Xerxes¹  Medeiros, Felipe¹  Brasil, Alex Nogueira²  de Oliveira, Leandro Soares¹  Lago, Rochel Montero¹ 

[1] Univ Fed Minas Gerais, Dept Quim, Inst Ciencias Exatas, BR-31270901 Belo Horizonte, MG, Brazil

[2] Biominas Engn Ind, Itauna, MG, Brazil

关键词: Acid catalyst;    Oleic acid;    Esterification;    Biodiesel cake;    Aromatization;    Sulfonation;   

DOI  :  10.1016/j.fuel.2015.02.027

来源: Elsevier

【 摘 要 】

In this work, an efficient heterogeneous acid catalyst for the esterification of oleic acid was prepared directly from oilseed cake by a simple sulfonation with concentrated H2SO4. Characterization by SEM/EDS, IR, Raman, TG, TG/MS, potentiometric titration showed that treatment with H2SO4 for 1, 2 and 4 h at 120 degrees C partially dehydrates the cake to form a carbon/cellulose composite which is sulfonated to produce strong -SO3H acidic sites. These surface sites were active for the esterification of oleic acid with yields ca. 84%, 88% and 94% in the presence of 5, 10 and 20 wt% catalyst, respectively. These results are comparable to 98% yield obtained with 1 wt% H2SO4 and higher than 75% observed for a high surface area (880 m(2) g(-1)) sulfonated activated carbon with similar number of -SO3H active groups. These results are discussed in terms of two effects: (i) the number of sulfonic surface acidic groups and (ii) the presence of a hydrophilic cellulosic fraction in the catalyst that adsorbs/traps water formed in the reaction shifting the esterification equilibrium and improving the yield. (C) 2015 Elsevier Ltd. All rights reserved.

【 授权许可】

Free