Biofuels for aviation: from bio-iso-butanol to synthetic paraffinic kerosene

Isobutyl alcohol from fermentation has been dehydrated to isobutene and this olefin has been oligomerized to a mixture of di-, tri- and tetra-isobutene over Amberlyst 15 catalyst, with more than 90 % selectivity to tri-isobutene, a branched C12 hydrocarbon that can be blended with jet fuel. Some key properties of this isobutene oligomers blend have been measured. Also, a process simulation scheme has been carried out with Aspen v9 to check the industrial feasibility of the whole scheme, including a third step of hydrogenation of the isobutene oligomers mixture, thus preventing a possible drawback due to lack of oxidative stability for the presence of olefins in this stream. The process simulation converges smoothly and the mass and energy balances and the preliminary equipment design predict the industrial feasibility of the whole process.