Catalisadores heterogêneos a base de heteropoliácidos e estanho para produção de biodiesel

• Autor(a) principal: Cardoso, Abiney Lemos
• 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/123456789/217
• topic: Biodiesel; Compostos de estanho; Catálise heterogênea; Heteropoliácidos; Esterificação; Biodiesel; Tin compounds; Heterogeneous catalysis; Heteropolyacids; Esterification; CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA INORGANICA

The biodiesel obtaining through esterification reactions comes if turning every viable day, because a great amount of acids present free fatty exists in rejeitos industrial, domestic or animal fats. However it is necessary the search for new catalysts that promote the esterification reactions. In this sense, the use of free heteropolyacids or supported has if shown a viable alternative for homogeneous and heterogeneous reaction in soft conditions. In this work we described the use of HPW and tin chloride supported for such reactions. HPW and supported SnCl2 were prepared by the impregnation method being used as head offices SiO2, Nb2O5 and ZrO2. The temperature of calcination of the composites was a studied variable, and the thermal treatments were tested to 100ºC, 200°C and to 300°C for 4 hours with different amounts of HPW and SnCl2 10, 30 and 50% m/m. The results of infrared for HPW show that the structure of HPW was conserved even in the most drastic treatment (300ºC). The Composites of HPW and SnCl2 were tested in reactions of esterification of the acids oleico with etanol. leaching tests were accomplished for all the composed with 50% m/m. the results show that besides the calcination temperature the head office type is also a decisive factor in the stability of the catalyst. It was accomplished a recovery test and reutilização for the composite of HPW50/Nb2O5-200 ºC and for SnCl250/SiO2-200ºC. A detailed kinetic study was accomplished being used RMN 1:00, were like this certain kinetic properties as activation energy and the kinetic constants, and such thermodynamic properties as balance constants, entalpia entropy and energy free from Gibbs for the reactions catalyzed by H3PW12O40 in homogeneous phase.