Catalytic synthesis of high-octane fuels from biologically-derived sources

Autothermal reactors using noble-metal catalysts have been shown to produce α-olefins from higher hydrocarbons such as biodiesel without a need for external heat input or regeneration. We aim to develop a staged autothermal reactor to carry out an additional hydroprocessing reaction and convert α-olefins to saturated branched hydrocarbons. We fabricated a reactor that contained a 0.5 wt % Pt/γ-Al ₂O ₃ stage with 10 g of zeolite H-BEA situated downstream of a 2 wt % Rh/α-Al ₂O ₃ stage. Decane was chosen as a surrogate for a higher alkane and was partially oxidized over the Rh stage to form C ₄₊ olefins with an 8% carbon yield and oxidation products H ₂, CO, CO ₂, and H ₂O. The H ₂ and hydrocarbon products formed in the Rh stage reacted on the downstream bifunctional zeolite stage and the C ₄₊ yield increased to 19%. This process also enhanced the percentage of branched isomers in the product distribution. The increase in yield of C ₄₊ products and the presence of branched isomers indicates the feasibility of integrating a hydroprocessing catalyst with a partial oxidation catalyst in a single-pipe autothermal reactor.