A low energy intensive process for the production of diesel fuel has been delineated from both 5-(hydroxymethyl)furfural (HMF) and its sugar precursor D-(-)-fructose. Alcoholic solutions of the above produced a mixture of potential bio-diesel candidates namely, 5-(alkoxymethyl)furfural, 5-(alkoxymethyl) furfural dialkylacetal, and alkyl levulinate, in the presence of solid acid catalysts. Sulfonic acid functionalized resins, Amberlyst-15 and Dowex DR2030 showed exceptional reactivity and selectivity for these reactions. Production of another potential diesel candidate 2,5-bis(alkoxymethyl)furan has been optimized through both sequential reduction/etherification and one-pot reductive etherification processes. During the metal catalyzed hydrogenation of HMF, platinum showed an exclusive selectivity for the reduction of the carbonyl functionality of HMF. Both Pt and Pt/Sn supported on Al 2 O 3 catalysts have been optimized for the production of 2,5-bis(alkoxymethyl)furan from HMF. The reaction mechanisms of etherification and reductive etherification have been discussed in detail on the basis of intermediates observed during these processes. † Electronic supplementary information (ESI) available. See

The etherification of furanyl alcohols produced from biomass-derived glucose and fructose has been a growing area of research for production of alternative diesel additives. We have determined that the Brønsted acidic resin catalyst, Amberlyst-15, is highly active and selective for the etherification of furanyl alcohols by both ethanol and butanol. The mechanism and kinetics of this reaction were investigated using 5-methylfurfuryl alcohol (MFA) as a probe molecule. Etherification of MFA was found to be first order in both the concentrations of furanyl alcohol and the acid sites. The mechanism of MFA etherification also holds for the etherification of 2,5-bis(hydroxymethyl)furan (BHMF) and 5-(hydroxymethyl)furfural (HMF). In the case of HMF, we find that acetalization of HMF precedes etherification in alcohol solutions. The apparent activation energy of furanyl alcohol etherification in ethanol and butanol solutions ranged from 17.0 to 26.3 kcal/mol. Electron donation/withdrawal at the 2 or 5 position of the furan ring in addition to solvent polarity was found to have significant effects on the rate of furanyl alcohol etherification.

Decarbonizing the transportation sector is critical to achieving global climate change mitigation. Although biofuels will play an important role in conventional gasoline and diesel applications, bioderived solutions are particularly important in jet fuels and lubricants, for which no other viable renewable alternatives exist. Producing compounds for jet fuel and lubricant base oil applications often requires upgrading fermentation products, such as alcohols and ketones, to reach the appropriate molecular-weight range. Ketones possess both electrophilic and nucleophilic functionality, which allows them to be used as building blocks similar to alkenes and aromatics in a petroleum refining complex. Here, we develop a method for selectively upgrading biomass-derived alkyl methyl ketones with >95% yields into trimer condensates, which can then be hydrodeoxygenated in near-quantitative yields to give a new class of cycloalkane compounds. The basic chemistry developed here can be tailored for aviation fuels as well as lubricants by changing the production strategy. We also demonstrate that a sugarcane biorefinery could use natural synergies between various routes to produce a mixture of lubricant base oils and jet fuels that achieve net life-cycle greenhouse gas savings of up to 80%.