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

Abstract

SummaryHerein, 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.

Lignin Valorization by Cobalt‐Catalyzed Fractionation of Lignocellulose to Yield Monophenolic Compounds

“…Rinaldi and coworkers have extensively studied Raney‐nickel catalysts in transfer hydrogenolysis of lignocellulose. By employing isopropanol as both a hydrogen source and a solvent, up to 25 wt % monomeric bio‐oil was obtained . However, careful optimization of reaction conditions is required as nickel catalysts tend to produce a mixture of aromatic and ring‐saturated products, and the catalyst is prone to deactivation .…”

“…By employing isopropanol as both a hydrogen source and a solvent, up to 25 wt % monomeric bio‐oil was obtained . However, careful optimization of reaction conditions is required as nickel catalysts tend to produce a mixture of aromatic and ring‐saturated products, and the catalyst is prone to deactivation . Recently, non‐noble‐metal nanoparticles supported on nitrogen‐doped carbon have attracted attention as substitutes for noble‐metal catalysts in various redox reactions .…”

Across the Board: Mark Mascal on the Challenges of Lignin Biorefining

“…In turn, aromatics‐directed HDO occurred at a temperature of 350 °C and an initial H 2 pressure of 0.5 MPa. Under both conditions, the process rendered two distinct main cuts of branched hydrocarbons (gasoline: C 6 –C 10 ; kerosene/diesel: C 14 –C 20 ) . Because transportation fuels are mixtures in any case, the complexity of lignin could even be seen as an advantage here.…”

“…Underb oth conditions, the process rendered two distinct main cuts of branched hydrocarbons (gasoline:C 6 -C 10 ;k erosene/ diesel:C 14 -C 20 ). [9,10] Because transportation fuels are mixtures in any case, the complexity of lignin could even be seen as an advantage here. Scheme1 gives ag raphical representation of a hypothetical lignin fragment containing all three subunits (G, H, and S) connected by the three major linkages (b-O-4, b-b, b-5) which,a ssuming no CÀCb ond cleavage, would yield the branched cycloalkanesshown on hydrodeoxygenation.…”

Catalytic Processes for The Valorization of Biomass Derived Molecules

“…At the same time, biomasses can be directly converted into liquid fuels and bio-oils via pyrolysis (thermal degradation process in absence of added oxygen) [21] or used as starting materials for the production of vegetable oils that are efficiently used in several energetic application [22,23]. Finally, a recent trend is surely the production of aromatics, including BTX compounds (benzene-toluene-xylene), starting from lignin, sugars and aromatic ethers, and esters in the framework of the so-called "lignin-first biorefinery" [24][25][26][27][28].…”