(33d) Low Temperature Conversion of Bio-Mass to Ultra-Clean Gasoline

The need for renewable fuels to reduce carbon emissions, improve economic security, and achieve energy independence is widely acknowledged and understood. Displacing large quantities of imported oil with domestic biofuels requires certain enabling technologies that are equivalent to those in an oil refinery.

Two of the most prominent technologies under consideration for biomass conversion, pyrolysis and gasification, have significant intrinsic limitations. Both gasification and pyrolysis involve very high temperature (500-1000°C) endothermic reactions and generally exhibit poor yields and problematic solid waste streams. Gasification is also very inefficient when the feedstock material contains more than 10% water. Enzyme or microbial routes to cellulosic ethanol are also popular. Even if the cost of the requisite enzymes or microbes can be greatly reduced, these technologies will still fail due to low product concentrations, high energy costs and long reaction times.

Exelus proposes a first-of-a-kind process to deconstruct biomass into a stable liquid feedstock and convert it to liquid transportation fuels. The final product is a mixture of alcohols that serve as a direct replacement for gasoline. This process finds the ?middle ground? between the slow, low temperature reactions catalyzed by enzymes and the fast, high-temperature, and un-selective reactions occurring in pyrolysis or gasification.

The Exelus concept overcomes the issue of highly reactive intermediates (sugars) reacting to form un-selective products like polymers and acids through the use of environmentally benign chemistry and innovative reactor designs. Liquid-phase aqueous processing is used to minimize the need to dry biomass and to provide both a solvent and reactant in the hydrolysis of biomass. A combination of low capital investment, high biomass utilization and lower processing costs translates into a cost of fuel produced via the new route of about $2.00/gal.