Santos, Eleonice MoreiraTeixeira, Ana Paula de CarvalhoSilva, Flávia Gontijo daCibaka, Thérèse EbambiAraújo, Maria HelenaOliveira, Willian Xerxes CoelhoMedeiros, FelipeBrasil, Alex NogueiraOliveira, Leandro Soares deLago, Rochel Montero2016-10-032016-10-032015SANTOS, E. M. et al. New heterogeneous catalyst for the esterification of fatty acid produced by surface aromatization/sulfonation of oilseed cake. Fuel Guildford, v. 150, p. 408-414, 2015. Disponível em: <http://www.sciencedirect.com/science/article/pii/S0016236115001684>. Acesso em: 26 set. 2016.0016-2361http://www.repositorio.ufop.br/handle/123456789/7006In 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 _C partially dehydrates the cake to form a carbon/cellulose composite which is sulfonated to produce strong ASO3H 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 m2 g_1) sulfonated activated carbon with similar number of ASO3H 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.en-USabertoAcid catalystOleic acidEsterificationBiodiesel cakeAromatizationArtigo publicado em periodicoO periódico Fuel concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 3957611079029.https://doi.org/10.1016/j.fuel.2015.02.027