Fernandes Júnior, Valter JoséOliveira, Tatiane Potiguara2019-02-132018-09-25OLIVEIRA, Tatiane Potiguara. Utilização do Óxido Bimetálico CaO-TiO2 na conversão catalítica do óleo de algodão (Gossypium hirsutum L.) em ésteres alquílicos (Biodiesel) via transesterificação metílica. 2018. 142f. Tese (Doutorado em Química) - Centro de Ciências Exatas e da Terra, Universidade Federal do Rio Grande do Norte, Natal, 2018.https://repositorio.ufrn.br/jspui/handle/123456789/26633Due to the increase in energy demand and pollution problems caused by the use of fossil fuels, the development of alternative fuels as well as other sources of clean and renewable energy has become necessary. Therefore, biodiesel has been consolidating as an excellent alternative. Transesterification is the most used reaction to obtain biodiesel, in which besides the vegetable oil, the presence of an alcohol and a catalyst is necessary. Among the heterogeneous catalysts, calcium oxide (CaO) has been highlighted due to the low cost and high activity, but its activity is caused by calcium ions in the polar phase that undergoes leaching. Thus, mixed oxides have been shown as an alternative to CaO. This study investigates the addition of titanium oxide to calcium oxide and the use of mixed oxide, CaO-TiO2, as the basic heterogeneous catalyst in the transesterification, from cottonseed oil (Gossypium hirsutum L.), in order to obtain alkyl esters (Biodiesel). These CaO-TiO2 mixed oxide catalysts were prepared in different molar ratios of Ca:Ti and then calcined at 800°C. The mixed oxides obtained were characterized by X-Ray Diffraction (XRD), Thermogravimetry (TG), Raman Spectroscopy, Scanning Electron Microscopy (SEM) coupled to Xray Dispersive Energy (EDS) analysis and N2 adsorption and desorption analysis .The catalysts obtained were used in the transesterification reaction with methanol: oil molar ratio of 20:1, 10% w/w catalyst and temperature of 60°C for 5h. The catalyst with the highest catalytic activity was 0.25Ca-0.75Ti, with conversion of 92,2%. Different calcination temperatures (800, 900 and 1000ºC) of 0.25Ca: 0.75Ti were tested, in addition to the variation of transesterification synthesis parameters. The best reaction conditions determined in this study were the methanol / oil ratio 20:1, 10 wt% catalyst at 60°C for 6 h reaction for the 0.25 Ca:0.75Ti-800 catalyst, calcined at 800°C, which presented a conversion percentage of 94.23%, and the anti-leaching and reuse ability. Therefore, the mixed oxide CaO-TiO2 has a great potential for obtaining biodiesel.Acesso AbertoCaO-TiO2BiodieselÓxido mistoCatalisadores heterogêneosTransesterificaçãodoctoralThesisCNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA