Cellulose ethanol
Cellulose ethanol
(OP)
Bio diesels are not new Brasil are great producers but, Richard Branson announced Virgin Fuel as a revolutionary Fuel.
Richard Branson He said “cellulose ethanol "is the by-product you get from the waste product (of plants), the bits in the field that get burned up," as opposed to ethanol which is produced from fruit or corn for example.”
Cellulose ethanol exhibits net energy content three times higher than corn ethanol and emits a low net level of greenhouse gases.
Some challenges of cellulose ethanol are: Corn requires an abundance of fertilizer to grow and carbon dioxide is emitted during ethanol production. The biggest opportunity for expanded production of ethanol will be from cellulose resources, however, this process is very expensive. The advancement and development of technologies for cellulose ethanol production is critical to expanding use of this fuel.
Luis





RE: Cellulose ethanol
RE: Cellulose ethanol
Hey, with the proper variety of hemp, energy use will fall 'way down, because nobody will want to go anywhere...
old field guy
RE: Cellulose ethanol
Doesn't have to be Corn or any current major cash crop. Basically you want to find the fastest growing/most efficient crop you can. I believe Switch Grass is one option being looked at although it is less energy dense (more acerage required for same energy) than corn although it takes less energy (fertilizer etc) to grow.
I believe you can also use what would otherwise be by product, straw, mulch etc.
RE: Cellulose ethanol
... except to the grocers.
RE: Cellulose ethanol
That's a good point. If we extract energy from the soil in the form of one crop or another, in a very short time the nutrients in the soil will be depleted and yields will go down. Then in order to increase yields, we have to get busy with adding fertilizers, at some expense of energy, and more intensive farming techniques, again with more expense of energy.
Anything less is pretty much the "slash and burn" farming methods used by semi-nomadic peoples the world over. Look at The Dust Bowl in the '20's. Those Okies didn't sart out with the intent of being nomadic, but the failures of crops due in part to tired soil turned them into nomads...
old field guy
RE: Cellulose ethanol
An optimistic estimate of the net energy of ethanol is zero! Not a good basis for x times claims.
HAZOP at www.curryhydrocarbons.ca
RE: Cellulose ethanol
owg I think 0707 meant in comparison to ethanol from just the grain. If you make ethanol from just the grain and throw the rest of the plant you get x usable chemical energy in ethanol. If you use the whole plant using cellulose break down methods then you get 3x usable energy. I don't think he was proposing breaking laws of thermodynamics.
If you mean the fact that some reports suggest that it takes as much energy to grow & process the corn as you get back from the ethanol that's another matter. Even if this is true it could still be a useful energy transformation method. If all the energy used to create the ethanol was from say wind (be it via electrical), and the ethanol used to run a vehicle this may still have enough advantages in certain situations over a land yacht or electric vehicle to make it worthwhile.
RE: Cellulose ethanol
Thus, the future of ethanol may depend on whether it can compete with crude oil on its own merits.
The concept of a bio refinery is modelled after petrochemical refineries, with production of multiple products at a single facility. Existing bio refineries include wet-mill corn processing and pulp and paper mills. As with petrochemical refineries, the vision is that the bio refinery would integrate several conversion processes to produce both transportation fuel (ethanol and bio diesel) and high-value chemicals or products, including ones that would otherwise be made from petroleum. Industrial bio refineries have been identified as the most promising route to the creation of a new domestic bio based industry.
Biomass would be classified as “Hard lignocellulose” (woody lignocellulose), “Soft ignocellulose” (herbaceous lignocellulose and dried excrement), “Starchy biomass” (rich in starch), and “Liquid biomass” (oils, black liquor and waste water rich in organics).
Should the secret of Virgin fuel be, to produce ethanol from a mix of human dried wastes mixed with herbaceous matter?
This is not new and most of the countries have policies of 3% to %5-bio diesel addition into fossil fuels
Richard Branson says:
“It will be called Virgin Fuel, yes! It's not ethanol-based as such, but it'll be a clean fuel. And if we've got it right, it could be a very important breakthrough. We think this fuel will work in cars and trucks and trains within a year. And we're hoping that it might work in commercial jet engines within five years, possibly sooner. So it will be able to work in Virgin Atlantic planes one day.”
What would it be?
Luis Marques
RE: Cellulose ethanol
"Cellulose molecules consist of long chains of glucose molecules as do starch molecules, but have a different structural configuration. These structural characteristics plus the encapsulation by lignin makes cellulosic materials more difficult to hydrolyze than starchy materials.
...
Since 5-carbon sugars comprise a high percentage of the available sugars, the ability to recover and ferment them into ethanol is important for the efficiency and economics of the process. Recently, special microorganisms have been genetically engineered which can ferment 5-carbon sugars into ethanol with relatively high efficiency. "
thats from: htt
I'm guessing they've got something, probably an engineered yeast, bacteria, or fungi which they believe they can use for a commercial scale conversion.
RE: Cellulose ethanol
htt
RE: Cellulose ethanol
RE: Cellulose ethanol
RE: Cellulose ethanol
Does it have potential? Sure. Unlike corn ethanol, it definitely has the potential to produce significantly more energy in fuel output than it consumes in fuel inputs. Why? Because there is a hell of a lot more cellulose in plant biomass than there is starch.
Does cellulose ethanol production have problems? Sure. Just like any other means of collecting and storing solar energy for use, cellulose ethanol has its share of problems, both in the refining and the source ethanol production area. These explain the delay in commercialization. And if it ever takes off, unsustainable agricultural practices WILL be used to produce the source cellulose. Why? Because, given our screwed-up inequitable "economics", these practices are "cheaper".
Until we're prepared to pay the full and fair cost of the energy we consume, including a tax/penalty for the emissions our fuel consumption produces, the cheapest fuel will remain the one we can pump out of a hole in the ground, or dig out of a hole in the ground.
RE: Cellulose ethanol
RE: Cellulose ethanol
go to
http
RE: Cellulose ethanol
http://www.iogen.ca
They already have a $30 million pilot facility built that makes a million gallons of ethanol per year, and they'd like to start building a bigger ($250 million) commercial plant.
RE: Cellulose ethanol
I disagree with the statement comparing ethanol made from grain to cellulose ethanol. The energy available is identical since the ethanol is identical in chemical composition. What the modifier "net" means could put some truth into that statement, if the cellulose based ethanol used no fuel to plant, cultivate or harvest and the process plant was more energy efficient. Otherwise, all ethanol is the same and resembles what gives my beer its kick.
RE: Cellulose ethanol
However you only come out ahead if the extra energy required to turn that waste into ethanol is less than the energy content made to grow the original crop.
Due to the lower sugar content of cellulose waste, and the difficulty of accessing the conents of each cell, that is not necessarily a slam-dunk.
Of course one question you need to always ask is what your aim is - reducing oil usage, or reducing greenhouse emissions, or saving money? They are not the same thing at all.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Cellulose ethanol
EXACTLY. Things that make sense for one set of goals may not for another.
Ragards,
Mike
RE: Cellulose ethanol
What is often termed power or energy generation is really energy conversion.
Certain types of energy are more useful for certain applications.
e.g. you could have a car with some kind of steam power plant burning crop waste. However, perhaps a vehicle burning ethanol derived from the crop waste is more efficient and/or easier to use and/or less costly and/or easier to fit into existing infrastructure etc.
So even though the efficiency from a pure thermodynamic stand point may not look good it may be worth the effort when you consider all factors, or at least the ones you can think of.
RE: Cellulose ethanol
RE: Cellulose ethanol
RE: Cellulose ethanol
Since only C, O and H is used up, the minerals may be
recycled to fertilize the field either by composting or drying and burning -- the later needs more energy and
would lose more N2.
Plesae read FAQ240-1032
My WEB: <http://geocities.com/nbucska/>
RE: Cellulose ethanol
"Cellulose ethanol can be produced from a wide variety of cellulose biomass feed stocks including agricultural plant wastes (corn stover, cereal straws, sugarcane bagasse), plant wastes from industrial processes (sawdust, paper pulp) and energy crops grown specifically for fuel production, such as switchgrass. Cellulose biomass is composed of cellulose, hemi cellulose and lignin, with smaller amounts of proteins, lipids (fats, waxes and oils) and ash. Roughly, two-thirds of the dry mass of cellulose materials is present as cellulose and hemi cellulose. Lignin makes up the bulk of the remaining dry mass.
As with grains, processing cellulose biomass aims to extract fermentable sugars from the feedstock.
But the sugars in cellulose and hemi cellulose are locked in complex carbohydrates called polysaccharides (long chains of monosaccharides or simple sugars). Separating these complex polymeric structures into fermentable sugars is essential to the efficient and economic production of cellulose ethanol.
Two processing options are employed to produce fermentable sugars from cellulose biomass. One approach utilizes acid hydrolysis to break down the complex carbohydrates into simple sugars. An alternative method, enzymatic hydrolysis, utilizes pre-treatment processes to first reduce the size of the material to make it more accessible to hydrolysis. Once pre-treated, enzymes are employed to convert the cellulose biomass to fermentable sugars. The final step involves microbial fermentation yielding ethanol and carbon dioxide.
Grain based ethanol utilizes fossil fuels to produce heat during the conversion process, generating substantial greenhouse gas emissions.
In the Cellulose ethanol production, fossil fuels are substituted by biomass. This property changes the emissions calculations.
Cellulose ethanol showed greenhouse gas emission reductions of about 80% [over gasoline], Corn ethanol showed 20 to 30% reductions. Cellulose ethanol's favourable profile stems from using lignin, a biomass by-product of the conversion operation, to fuel the process. Lignin is a renewable fuel with no net greenhouse gas emissions. Greenhouse gases produced by the combustion of biomass are offset by the CO2 absorbed by the biomass as it grows.
Feedstock sources and supplies are another important factor differentiating the two types of ethanol. Agricultural wastes are a largely untapped resource. This low cost feedstock is more abundant and contains greater potential energy than simple starches and sugars. Currently, agricultural residues are plowed back into the soil, composted, burned or disposed in landfills. As an added benefit, collection and sale of crop residues offer farmers a new source of income from existing acreage.
Industrial wastes and municipal solid waste (MSW) can also be used to produce ethanol."
RE: Cellulose ethanol
If your goal is energy efficiency, it would be better to simply burn the biomass feedstock to produce heat and use that to offset fossil fuels currently used for that purpose, until all such large stationary users of fossil fuels have their fuel needs satisfied. The "minerals" don't burn, so those can still be used for fertilization. Any screwing around you do to convert biomass to liquid fuels suitable for transportation invariably has a high energy efficiency penalty associated with it. Something about shaving off the edges of square pegs to fit round holes just bothers me.
RE: Cellulose ethanol
They appear to be building two large hoppers to do more of the same.
HAZOP at www.curryhydrocarbons.ca
RE: Cellulose ethanol
Does a cellulose process for ethanol create a usable byproduct like corn ethanol does?
RE: Cellulose ethanol
But your energy needs are stationary rather than for transportation, it's still far better to use the biomass feedstock for burning rather than going through all these energy-lossy conversion steps first. And until all our stationary energy needs are satisfied by renewable energy sources, why would we even BOTHER going after transporation fuels? Last time I checked, we were still burning a sh*tload of coal and natural gas and even bunker oil to make electricity?!?!