Oxygenated fuels, furan derivatives

Mechanisms related to cellulose-derived biofuels focus on the chemistry offuran derivatives. Beyond the unimolecular decompositions and oxidative reactions discussed previously in this section, furan derivatives can undergo a wide variety of other reactions. They are transformed by pyrolytic, hydrolytic, and other chemical processes to longer chain ethers (R1OR2) and aldols (hydroxyaldehydes and hydroxyketones, Ri(0H)R2C(0)R3). These oxygenated species are then converted through hydrogenation and deoxygenation processes to liquid HC fuels (alkanes). 

Hydrodeoxygenation involves the removal of oxygen from various oxygen containing compounds in petroleum feedstocks. The oxygen content in petroleum crudes is very low, typically of the order of less than 0.1 wt%. Carboxylic acids and to a lesser extent phenols are found in low- and medium-boiling fractions. However, fuels derived from tar sands, shale oils, and coal have a substantial amount of oxygen compounds. These may include ethers, furan, carboxylic adds, and phenols. 

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