Qualidade do biodiesel: degomagem, perfis de ácidos graxos e misturas de biodiesel de diferentes matérias primas

• Autor(a) principal: Santos, Eleonice Moreira
• Data de Publicação: 2011
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/311
• topic: Biodiesel; Soja; Perfil de ácidos graxos; Biodiesel; Soybean; Fatty acid content; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA

Biodiesel derived from oils crops or animals fats is a potential renewable and alternative to pretroleum fuels. Chemically, biodiesel is monoalkyls esters of fatty acids, produced by transesterification. Structural features of fatty ester molecule that influence the physical and quality fuel properties are carbon chain length, degree insaturation, and branching of the chain. The oxidative stability and cold filter plugging point (CFPP) are affected in opposite ways by fatty acids. The increased unsaturated fatty acids content decreases the oxidative stability and improves the CFPP. Besides influence of fatty acids in biodiesel quality, the presence of phosphorus in biodiesel, drastically affects the catalyst performance. To evaluate some aspects of biodiesel quality, a study was performed about: importance of pre-treatment of vegetable oils for reduction in the phosphorus content; evaluation of a soybean line genetically modified to reduction in the linolenic acid content for biodiesel production; the use of biodiesel blends in the improvement of the oxidative stability and CFPP. In evaluating the use of degumming as pretreatment to reduce of phosphorus content in conventional soybean oil, soybeans containing low content of linolenic acid and jatropha using water degumming and acid degumming, the two tested methods were efficient in the reduction of phosphorus content in oils and did not affect the free acidity. In the evaluate of the low linolenic acid soybean performance for biodiesel production by comparing with conventional soybean, the results show that low linolenic acid soybean biodiesel has a higher oxidative stability that conventional soybean, and the CFPP for both is similar. In the evaluation of influence of biodiesel blends of conventional soybean and low linolenic acid soybean with jatropha and palm biodiesel, in the biodiesel properties - oxidative stability and CFPP - the profile and fatty acid content present strong correlation with these properties. Changes in the fatty acids esters content provided by blends show that CFPP for biodiesel blends of conventional soybean and low linolenic acid soybean with jatropha and palm have similar behavior. For oxidative stability the best values were for biodiesel blends with low linolenic acid soybean, jatropha and palm. Considering the results, improvements in the biodiesel quality can be achieved by simple pretreatment, such as water degumming for reduce in the phosphorus content; genetic modifications in the oil fraction for use as feedstock for biodiesel production; or through by biodiesel blends of different feedstocks, obtained combinations that improvement of oxidative stability and CFPP, besides other properties.