Joule
Volume 2, Issue 6, 20 June 2018, Pages 1118-1133
Journal home page for Joule

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

https://doi.org/10.1016/j.joule.2018.03.012Get rights and content
Under a Creative Commons license
open access

Highlights

  • Lignin-first biorefinery produces gasoline and kerosene/diesel drop-in fuels

  • A H2 self-sufficient deep converting lignin-first biorefinery is achievable

  • H2 surplus releases cellulose for the production of platform chemicals

  • Chemicals further monetize the deep converting lignin-first biorefinery

Context & Scale

Heterogeneous catalysis is no longer limited to the conversion of lignin wastes from cellulosic-centric industries, but has expanded to offer innovative solutions for the deconstruction of lignocellulose by reductive processes. Such solutions are referred to as lignin-first biorefining. They are highly efficient at preventing the generation of recalcitrance in the lignin streams while yielding delignified pulps. Herein, a lignin-centered convergent approach rendering two main cuts of branched hydrocarbons (gasoline: C6-C10, and kerosene/diesel: C14-C20) is introduced. As the hydrodeoxygenation of lignin streams is H2-intensive, the utilization of pulp as an H2 source via gasification is proposed. The cellulosic H2 shows potential for covering the H2 demand for the production of drop-in lignin fuels. Importantly, the energy content of the lignin fuels relative to the energy content of the lignocellulose is approximately 2- to 2.5-times higher than that of cellulosic ethanol. Therefore, it is now timely to question whether cellulosic bioethanol is the most sensible target fuel from lignocellulose.

Summary

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.

Keywords

biofuels
lignin
lignin-first biorefinery
HDO
aromatics
catalytic upstream biorefining
lignin fuels
phosphidated nickel catalysts
hydrodeoxygenation
Raney Ni
hydrogen transfer

Cited by (0)

3

Lead Contact