WiSys Technologies

Lignin-Solvent Fuel

WiSys Technology Number: T08010US
Patent Number: 8,211,189
Patent Issued Date: July 12, 2012 (PDF)
Stage of Development:

The process is being scaled up from a laboratory system


Renewable energy production is an increasingly important issue both nationally and globally. Biofuels are a promising source of renewable energy due to their promise to reduce greenhouse gas emissions and increase energy security by lowering energy imports. Current biofuel technologies are focused largely on ethanol as a liquid transportation fuel. Ethanol contains less energy per unit of gasoline and requires corn, an important source of food for production. Additionally, since ethanol is soluble in water, separation via distillation is an energy intensive process. A fuel produced in a less soluble solvent would be separable using gravity and constitute a much less energy intensive production process. Biofuels produced from cellulose and lignin obtained from cellulosic biomass will not compete with a source of food and may offer a more energy dense biofuel with a less energy intensive production process.


Researchers at UW-Stevens Point have developed a new process for obtaining liquid biofuels from a variety of woods, agricultural refuse, and bioenergy crops. Lignin, a major component of wood and other organics, can be separated from cellulose and hemicellulose in an organosolv pulping process using n-butanol as the pulping solvent. The lignin is soluble in n-butanol but the n-butanol is insoluble in water, so the solvent and lignin can be easily separated; the energy intensive distillation process used in ethanol production is avoided. The resulting lignin-solvent mixture is expected to be a suitable replacement for transportation fuels. This mixture may also be combined with biodiesel to offer improved energy density and a lower gelling temperature. The lower gelling temperature makes this mixture suitable for JP-8 aviation fuel. Additionally, retaining the lignin and solvent together in a mixture will reduce the equipment fouling that has been associated with lignin. This improved organosolv process is superior because such a wide variety of raw materials can be utilized, the lignin product is easily purified, and the lignin-solvent mixture is very useful as a fuel both independently and mixed.


  • The lignin-solvent mixture may be used as a transportation fuel independently
  • The lignin-solvent mixture may also be combined with biodiesel to replace JP-8 aviation fuel


  • A variety of sources of biomass may be used such as hardwood and softwood trees, bioenergy crops (Miscanthus or switchgrass), and agricultural refuse (sugar cane, corn stover, wheat straw)
  • The separation is less energy intensive than ethanol production in water
UW-Stevens Point UW-Stevens Point
Don Guay
Professor of Paper Science and Engineering
Eric Singsaas
Professor of Biology