Thermal cracking of oleic acid promoted by iron species from iron ore tailings for the production of ketones and fuels.

Abstract

Iron ore tailings (IOT) are rich in iron oxides and silica and can be used for different applications such as allow the thermal cracking of fatty acids for the production of fuels and products with high added value. Thus, this work aimed to use of IOT as an iron source for the production of high-value products using oleic acid (OA) as carbon sources. These compounds were produced from a thermal decomposition reaction, from the mixture of OA and IOT, in a high pressure reactor (12.5 bar), using the ratio of 1:1 wt (acid:IOT), in temperatures between 250 and 450 ◦C (3 and 12 h). The results showed that for all reactions, the solid products obtained showed a percentage of less than 6 % of carbon material and different iron phases (Fe2O3, Fe3O4 and FeOOH). For the reactions carried out at 250 and 350 ◦C/3h the main fraction obtained was the liquid, however the compostion was mainly the starting compound and iron oleate. For the reactions carried out at 400 and 450 ◦C/3h, the main fraction was gas, mainly hydrogen. For the reaction carried out at 350 ◦C for 12 h the mass balance showed the formation of similar amounts of liquid and gaseous products. Liquid products formed ketones as the main product, while gaseous products were identified and presented greater selectivity for C3 hydrocarbons.