Environmental Engineering Reference
In-Depth Information
gasoline is still being developed. The following
are a brief sampling of patents and patent appli-
cations, and illustrate the variety of work in this
exciting area.
cally improve the yield of fermentable sugars
from cellulose.
Integrated Process Patents
BioJoule has applied for a patent (“Process for
the production of biofuel from plant materials”,
#20070259412) for an integrated approach for
removing lignin from the biomass feedstock using
ethanol under pressure, removing the five-carbon
sugar xylose from the remaining plant material,
and finally converting the cellulose that is left
into sugar which is then fermented into ethanol.
On a much smaller scale, patent application
#20070117195 (“Integrated thermochemical and
biocatalytic energy production system”) integrates
gasification of low-moisture wastes with hydroly-
sis and fermentation of high-moisture wastes—all
contained on a small flatbed trailer, designed to be
taken into remote military operations where waste
disposal and a lack of energy and electricity can
be a major problem.
Many more interesting patents could be re-
viewed, but hopefully these few examples serve to
show the extent of the interest, effort, and money
currently being expended on cellulosic ethanol
research and development.
Feed Stocks
Patent application #20070250961 (“Energy crops
for improved biofuel feedstocks”) relates to geneti-
cally engineering plants to produce not only more
biomass, but also the enzymes required to convert
the lignocelluloses into fermentable sugars. Other
efforts are aimed at hybridizing plants so that they
produce less lignin and more cellulose
Iogen discovered that a key to selection of a
good feedstock is the ratio of fiber to cellulose it
contains (“Pretreatment process for conversion of
cellulose to fuel ethanol”, patent # 6090595). This
may seem like an odd “invention”, but it certainly
helps focus the efforts of those wishing to grow
particular feed stocks for biofuel manufacture.
Pretreatment
Martin Marietta Energy Systems was awarded
a patent for an “Enhanced attrition bioreactor
for enzyme hydrolysis of cellulosic materials”
(#5508183). By combining pretreatment and
hydrolysis, this process increases the efficiency
of the operation and reduces its cost.
SELECTION OF SUPPLY
CHAIN COMPONENTS
Hydrolysis
A patent application filed in January of 2007
(“Systems and methods for producing biofuels
and related materials”, #20070178569) is for ways
to use the recently discovered capability of the
anaerobic bacterium
Clostridium Phytofermentans
to ferment cellulosic biomass into ethanol and
other useful products. This application illustrates
the effort to develop biological organisms capable
of simultaneously hydrolyzing and fermenting
cellulose into ethanol.
Another application (“Methods for enzymatic
hydrolysis of lignocellulose”, #20070218530)
relates to mixtures of enzymes that synergisti-
There are three major components of an efficient
cellulosic ethanol supply chain. These include
growth and collection of raw materials, conver-
sion process, and ethanol distribution. A number
of different options exist for the implementation of
each of these supply chain components. Establish-
ing a sustainable cellulosic ethanol supply chain
depends on the proper selection of components
for a given region, in this case Oregon.
