Biomass-to-Liquids Processes

There is an intense world-wide effort devoted to the conversion of biomass into oxygen-containing chemicals. In marked contrast to the scale of the effort devoted to chemicals, the direct conversion of biomass into oxygen-free hydrocarbon fuels has been dominated by the pioneering work from only two research groups.

The goal of converting biomass derivable sugars into gasoline-grade hydrocarbons consists of two conceptual steps. First, the oxygen content of the sugars must be reduced by cleaving the hydroxyl groups while replacing them with C-H moieties. Second, the chain length must be upgraded from the C5-C6 range of the starting sugars into the C8-C12 range of gasoline. There is precedent for both steps although, the second step is the most challenging and is the primary focus of this proposal.

The major challenge in producing gasoline grade hydrocarbons is to upgrade the carbon backbone from the C5-C6 range of the starting sugars into the C8-C12 range of gasoline. We propose to upgrade the hydrocarbon chain length catalytically by a carbonylation/hydrogenation route that has some analogy to our work on the olefin hydroformylation reaction. We will employ inexpensive first-row homogeneous transition metal catalysts that hold significant promise for being much more selective, active and robust than the existing heterogeneous systems. Furthermore, our catalytic approach is expected to lead to branched hydrocarbons with high-octane ratings.