(6dh) Novel Routes to the Synthesis of Fuels/Lubricants and Chemicals from Biomass Derived Synthons

As the world’s accessible oil reservoirs are gradually depleted, it is important to develop suitable long-term strategies based on the utilization of renewable fuel that will gradually substitute the declining fossil fuel production. In this context, lignocellulosic biomass would ideally supply fuel/chemical markets and be fully compatible with existing petroleum infrastructure. Biological transformations, though efficient, typically produce bio-fuels like ethanol or carboxylic acid esters that can only be used at limited blend levels and integrate poorly with current fuel handling. Thus the development of new catalysts and methods is essential to move the energy related research forward. We recently reported different chemical routes to convert lignocellulosic products from a variety of renewable carbohydrate sources into hydrocarbons that can be used for gasoline, jet fuel, and diesel. As most natural fermentation products have lower carbon numbers coupling chemistry is needed to design larger molecules, ideally achieved by exploiting the functionalities present in the starting materials. We have shown that dehydrogenation reactions of fermented primary and secondary alcohols or ABE mixture can be readily converted to carbonyl compounds which on subsequent aldol-type condensation provides an excellent
procedure for increasing the carbon number and decreasing the O/C ratio of bio-derived molecules through removal of oxygen as water. For instance, we show that the secondary amine-functionalized silica can be used in the very selective dimerization of aldehydes and methyl ketones to produce molecules that are components of jet-diesel fuel and lubricants. The catalytic activity of secondary amine supported silica sample can be altered significantly by controlling the Bronsted acidity of M-OH (M = Al, Ti, Zr, Sn) species present on the support. These least oxygenated products were subjected to mild hydrodeoxygenation conditions in the subsequent step, in order to remove unsaturation as well as the oxygen atom make them as usable fuels.