Wisconsin Alumni Research Foundation

Clean Technology
Clean Technology
Two-Step Process Converts Lignin into Simple Aromatic Compounds
WARF: P140205US01

Inventors: Shannon Stahl, Alireza Rahimi, Joshua Coon, Arne Ulbrich

The Wisconsin Alumni Research Foundation (WARF) is seeking commercial partners interested in developing a selective, low-cost method to convert oxidized lignin or lignin-type materials into simple aromatic compounds.
Lignin is a major component of non-edible biomass. It is a cheap byproduct of pulp and biofuel production and is one of the few naturally occurring sources of valuable aromatic compounds. Converting lignin’s complex biopolymer structure into simple organic chemicals has attracted major interest.

For example, the world’s supply of artificial vanillin is produced by oxidizing spent sulfite liquor. However, this requires a chemical feedstock that arises from an expensive and polluting sulfite pulping process used in few mills today. Other production methods are hazardous, energy intensive or unsuitable on an industrial scale.

UW–Madison researchers previously developed a highly efficient method to oxidize lignin or lignin subunits (see WARF reference number P130104US01). This work represented the first step towards a greener, cheaper conversion strategy.
The Invention
Building on their work, the researchers have now developed a two-step process for selectively converting lignin and lignin-type material into low molecular weight aromatic compounds.

The lignin is first selectively oxidized via the previously described method, then reacted with an organic carboxylic acid, salt or ester (e.g., formic acid) for a time and temperature sufficient to cleave carbon-carbon or carbon-oxygen bonds. The process results in high yields of simple aromatic compounds.
  • Conversion of lignin to valuable aromatic fine chemicals
Key Benefits
  • Strong reactivity and selectivity
  • No expensive catalysts
  • Potential to be industrially scalable
  • No harmful or difficult-to-handle reagents
Stage of Development
The new process has been used to produce a mixture of small aromatic compounds (including vanillin, syringic acid and HMF) from an aspen-derived lignin sample.
Additional Information
For More Information About the Inventors
For current licensing status, please contact Jennifer Gottwald at [javascript protected email address] or 608-960-9854