A Convergent Approach for a Deep Converting Lignin-First Biorefinery Rendering High-Energy-Density Drop-in Fuels

Herein, a lignin-centered convergent approach to produce either aliphatic or aromatic bio-hydrocarbons is introduced. First, poplar or spruce wood was deconstructed by a lignin-first biorefining process, a technique based on the early-stage catalytic conversion of lignin, yielding lignin oils along with cellulosic pulps. Next, the lignin oils were catalytically upgraded in the presence of a phosphidated Ni/SiO₂ catalyst under H₂ pressure. Notably, selectivity toward aliphatics or aromatics can simply be adjusted by changes in H₂ pressure and temperature. The process renders two distinct main cuts of branched hydrocarbons (gasoline: C₆-C₁₀, and kerosene/diesel: C₁₄-C₂₀). As the approach is H₂-intensive, we examined the utilization of pulp as an H₂ source via gasification. For several biomass sources, the H₂ obtainable by gasification stoichiometrically meets the H₂ demand of the deep converting lignin-first biorefinery, making this concept plausible for the production of high-energy-density drop-in biofuels.