Assessment of Conversion Technologies for Bioalcohol Fuel ...

Development Status–BioEnergy International claims to be developing a “pipeline of
novel biocatalysts”, but has not publicly released information about its curent activities
or progress involving development of a cellulosic biomass-to-alcohol process.
Future Plans–As it moves forward with its conventional corn-to-ethanol projects,
BioEnergy International intends to continue improving its process technology for the
production of ethanol from biomass, including the fermentation of sugars generated
from the processing of the cellulose components of agricultural wastes, to augment its
corn based process technology. The company’s goal is to have this technology ready
for commercial deployment at one of its corn-to-ethanol plants by 2008.
Brelsford Engineering, Inc., Bozeman, Montana
Organizational Background–Brelsford Engineering Inc. (BEI) has developed a
cellulosic biomass-to-ethanol technology based on a patented hydrolysis process
utilizing dilute acid. Part of BEI’s development eforts have been funded by the
Montana Renewable Energy Foundation. BEI’s development originated with a smalscale
grain-based ethanol production plant designed, built, and operated for USDOE
by EG&G Idaho, Inc. at the Idaho National Engineering Laboratory (INEL) in 1980. It
was dismantled in 1982. Subsequently, BEI obtained the complete EG&G Idaho
Engineering Designs and Reports.
Technology Characteristics–The BEI process, shown in Figure A9, utilizes a dilute
acid two-stage plug-flow reactor system. The slurry feedstock is fed into the feed
tank, where sulfuric acid is combined with biomass. The slurry goes through a
progressive cavity pump to the primary reactor that operates at 135°C. The output of
the primary reactor is centrifuged then exposed to fresh sulfuric acid and heat. The
feedstock goes through a slurry mixer and then into the secondary reactor, which is
kept at 180°C. The slurry is then flashed to lower the temperature. Waste heat is
recycled to the primary reactor. The acid and water mixture is then returned to the
slurry feed tank where it re-enters the system. The slurry goes back into the primary
reactor to produce highly concentrated sugars. The sugars are fermented to produce
ethanol.
Development Status - BEI has completed bench-scale and pilot-plant testing of its
process. However, the results of these tests are not publicly available. The company
claims to have tested its process with the following feedstocks: soft and hardwood saw
milling wood wastes; wheat and barley straw; corn stover and corn fiber; and municipal
refuse-derived cellulose and green wastes.
Future Plans–BEI offers for private sale the industrial design of the BEI Cellulose
Hydrolysis Processing & Reactor System, along with specifications of available
process equipment, instruments and control systems.
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