Cellulosic
technology is a key to significant reduction of
greenhouse gases and is a significant global
warming technology.
What is cellulosic
technology?
Cellulosic technology is a set of technologies
to convert nonfood biomass, such as wood, energy grasses or waste paper,
to biosugars such as glucose and xylose. Cellulosic
technologies encompass all the aspects of making biofuels and renewable plastics
from cellulosic biomass. Such technologies include enzyme manufacture, cellulose
and hemicellulose hydrolysis, biomass pretreatment, and lignin combustion or
conversion. Two major types of cellulosic ethanol technology are 1) gasification
of biomass to synthesis gas and resynthesis of larger molecules like ethanol,
and 2) enzymatic hydrolysis of cellulose and hemicellulose to component sugars,
followed by fermentation or chemical conversion to cellulosic ethanol or other
advanced biofuels. Gasification methods have the advantage of being fast and
relatively less sensitive to feedstock type, but the disadvantage of destroying
useful structures like the glucose molecule. Enzymatic methods are slower, but
produce glucose, which is the metabolic substrate of choice for producing
ethanol, butanol, renewable diesel, renewable jet fuel, and a wide variety of
useful biobased chemicals as industrial feedstocks for bioplastics,
renewable chemicals and solvents.
General Biomass Company develops advanced
enzymes to make bioplastics and renewable chemicals from nonfood biomass and
municipal solid waste. Our engineered cellulase and hemicellulase enzymes make
biosugars - glucose and xylose - from cheap nonfood biomass. Glucose and
xylose are universal substrates for all industrial fermentations, allowing
production of a wide variety of renewable chemicals and bioplastics. They
are also substrates for cellulosic ethanol and advanced biofuels
such as green gasoline, green diesel and biojetfuel.
By providing cheap sugars from nonfood biomass, our enzymes
enable production of drop-in bioplastics without the use of grain,
starch, palm oil and other food-based sources. Recycling these plastics actually
removes CO2 from the atmosphere and sequesters it naturally
in structures such as building materials and playground equipment.
What are drop-in
bioplastics?
Drop-in
bioplastics are biobased equivalents to widely used plastics like
polyethylene and polypropylene. The advantage of these bioequivalent plastics,
apart from not using oil, is that they can be used in existing production lines
and they fit into the current recycling stream. Polyethylene can now be made
from ethylene manufactured from sugar cane ethanol. It has an advantage over
biodegradable or PLA plastics in that it drops into the current recycling
system. If the ethanol is made from cellulosic biomass, e.g. sugarcane bagasse,
then we have a complete lifecycle system in which green plants, e.g sugarcane,
pull CO2 out of the atmosphere, and the carbon winds up in a plastic product or
plastic packaging. Recycling that plastic and forming it into permanent
structures such as playground equipment or structural plastic effectively
sequesters carbon taken from the atmosphere, vs plastics made from oil.
What is cellulosic ethanol?
Cellulosic ethanol is fuel ethanol made
from glucose, a 6-carbon sugar derived from the cellulose in biomass.
Cellulosic ethanol is a substitute for gasoline. It is chemically identical to
ethanol made from food crops like corn and sugar, but comes from wood, waste
paper, and energy crops like poplar and switchgrass. Cellulosic ethanol is more
difficult to make, because cellulose is a tough structural material, unlike
starch from grains which is easily broken down to glucose sugar.
The primary feedstocks for fuel ethanol today include glucose
from corn starch in the U.S., currently producing about 12 billion
gallons of corn ethanol per year. Additional corn ethanol plants could push the
total to 15 billion gal/year, with the downside of increasing corn prices and
encouraging the shift of wheat and soybean acreage to corn. One bushel of corn
produces about 2.8 gal ethanol, so 12 billion gal corn ethanol requires about
4.3 billion bu/year, a significant fraction of the U.S. corn crop.
In Brazil, the primary feedstock for fuel ethanol is sucrose
(white sugar) from sugar cane, a more efficient source than corn.
Standard gasoline in Brazil is about 25% ethanol, and flexfuel vehicles using
E85 are popular. Growing large amounts of sugar cane is not an option in the
U.S., Canada and Europe because of the tropical climate required.
Cellulosic ethanol can be made from a variety of
biomass feedstocks including recycled paper, urban waste paper diverted from
municipal solid waste (MSW), agricultural wastes like sugarcane bagasse and corn
stover, energy crops like poplar, willow, and switchgrass, wood waste, and waste
streams from pulp and paper mills. Cellulose and hemicellulose are
the two carbohydrate components in most biomass, and can be hydrolyzed (split)
into their component sugars: glucose, xylose, both of which can
be fermented to ethanol, other biofuels like butanol, green diesel or
biojetfuel, or lactic acid which can be made into biodegradable or more
permanent plastics and fabrics. Cellulosic ethanol is also a sustainable
feedstock for drop-in bioplastics like renewable plant-based polyethylene and
polypropylene.
and
Why should we make cellulosic
ethanol?
Cellulosic ethanol made from biomass will produce
smaller amounts of greenhouse gases than corn ethanol, and far less than the
gasoline it will replace. This greenhouse reduction potential can be estimated
by Life Cycle Analysis (LCA), used by numerous groups to evaluate the net
energy balance and carbon balance of ethanol from corn and cellulosic biomass.
The two best examples of this analysis are (1) from Kammen's lab at Berkeley -
Farrell et al. (2006) Ethanol
Can Contribute to Energy and Environmental Goals and (2) from Michael Wang
(2005) at Argonne National Lab in Chicago: Updated Energy and
Greenhouse Gas Emission Results of Fuel Ethanol.
With continued technology improvements, cellulosic ethanol
will become cheaper than gasoline. Because it is locally made, it reduces the
transfer of wealth caused by oil imports. E85
Hybrids can drastically reduce gasoline consumption.
What is cellulose and where does it
come from?
Cellulose is a
polymer or string of glucose molecules joined
together in linear rows. The parallel rows of glucose molecules form a tough
crystalline substance which gives wood, paper and cardboard their strength.
Cellulose comprises about 40-60% of the material in common forms of biomass,
such as wood, paper, switchgrass, and corn stover. Cellulose is probably the
most abundant organic molecule on the planet.
The other biomass components are hemicellulose, made from 5-carbon sugars like xylose,
and lignin, which is a set of non-sugar
molecules acting like a glue to hold the biomass molecules together. The
5-carbon sugars, or pentoses, can also be fermented to ethanol, and the lignin
can be burned for energy or spun into high-strength carbon fibers for the
light carbon composites used in wind turbine blades and aircraft parts. With
further cost reductions, carbon fibers made from biomass lignin should become
part of an increasing new market for light weight automobiles, including EVs.
Glucose, xylose and lignin from biomass are currently the only feasible
alternatives for large-scale substitution of petroleum hydrocarbons.
E10, E15 and E85
E10 is a blend of 10% ethanol and 90% gasoline which runs in all
standard automobiles without modification. Assuming the U.S. uses 140 billion
gal of gasoline per year, it would take 14 billion gallons of ethanol to make
all U.S. gasoline as E10. Ethanol has about 2/3 the energy content of gasoline
per gallon compared to gasoline, but has a higher octane rating. Wholesale
gasoline is purchased as RBOB, a lower octane gasoline to which an octane
enhancer like ethanol must be added to make retail gasoline. Previous octane
boosters like MTBE and tetraethyl lead have been outlawed due to their
environmental toxicity. Ethanol is a natural substance which is rapidly degraded
in the environment.
E15 is a blend of 15% ethanol and 85% gasoline which
runs in most U.S. automobiles. In January 2011, based on extensive testing, the
EPA ruled that E15 could be sold for use in all automobiles made after 2001,
about two thirds of all cars on the road today. This effectively removes the
"blend wall" and increases U.S. ethanol demand by 50% or 7 billion gal/year,
nearly all of which must come from cellulosic ethanol, since the Renewable Fuels
Standard (RFS) limits corn ethanol to 15 billion gal.
E85 is a blend of 85% ethanol and 15% gasoline which
runs in flexfuel vehicles, or FFVs. There are about 8 million FFVs in the
U.S. and millions more in Brazil and other countries. FFV technology costs about
$200 per vehicle and consists of modifications to the fuel injection computer,
gas lines, etc., and sometimes a larger gas tank. FFVs allow a driver to fill up
with any mixture from straight gasoline to E85, with the automotive system
automatically sensing and adjusting the air/fuel mixture appropriately. New
blender
pumps let the customer choose to fill up with E10, E20, E30, E50 or E85,
if they drive a FFV.
Widespread blending and sale of ethanol blends is thus the
next stage in wider use of biofuels like cellulosic ethanol, assuming the
appropriate ethanol and fuel pumps are in place. To date, the major oil
companies have resisted the expansion of E85, since the retail product contains
only 15% gasoline made from oil. This creates a large opportunity for
vertically integrated cellulosic ethanol companies which would have
access to biomass feedstocks, refine the ethanol, blend it as E85, and sell it
at retail E85 stations, which could offer snacks and other fuel pumps
much like gas stations today. The difference would be that the bulk of the fuel
product is renewable, and branding and ownership would reside in new companies.
Technology now exists to make green gasoline from biosugars, so E85 may soon
be 100% renewable and made without any oil.
What is General Biomass Company
doing?
General Biomass Company uses advanced biotechnology to
develop custom biomass deconstruction enzymes. Each nonfood biomass feedstock is
different: old newspapers require different enzymes than sugar cane bagasse or
nut hulls or coffee bean husks or beetle-killed pine. We use a deep knowledge of
biomass structure and sophisticated genomics tools to find the right enzymes for
each feedstock, and produce them efficiently for R&D, pilot plant and
commercial scale processing.
We can help you become more sustainable. We offer consulting,
custom enzyme development, and an enzyme scaleup path to pilot and commercial
production that fits your feedstock. Please contact us with your needs.
General Biomass Company
2906 Central Street, #134
Evanston, IL 60201
U.S.A.
Email: dgibbs@generalbiomass.com
Phone: 847-624-3590
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