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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Thu Jul-14-05 07:45 PM
Original message
American Chemists report a chemical method for ethanol from cellulose.
Edited on Thu Jul-14-05 07:46 PM by NNadir
Much ado has been made - and not without good reason - for the use of cellulosic ethanol. The methods currently employed are, however, enzymatic and therefore suffer from many drawbacks, including cost, the necessity for huge amounts of water, speed, and catalytic lifetime. For this reason, the following paper in the ASAP section of the journal Energy and Fuels is of interest:


"Pretreatment processes enhance hydrolysis of cellulose-containing materials by disrupting cellulose crystallinity,removing lignin, and/or removing hemicellulose.Among the various pretreatment methods, hydrothermolysis using steam or water has shown to be effective in removing and solubilizing hemicellulose.1,2 Pressure-cooking corn fiber or corn residue in water at a controlled pH effectively dissolves hemicellulose, glucans, and some of the lignin while minimizing loss of sugar due to degradation of monosaccharides by minimizing formation of the monosaccharides during the pretreatment step.3-6 Thus, dissolved oligosaccharides produced from liquid hot water pretreatment of biomass need to be further hydrolyzed to fermentable monosaccharides. Cellulases and xylanases function at 40-50 °C and do not form monosaccharide degradation products. Hence, they are attractive. However, these enzymes are expensive and contribute as much as $0.20-0.30/gal ($0.05-0.08/L) to the production cost of ethanol.7 Consequently, we have initiated studies on the mechanisms, robustness, and costs of acid catalysts in the form of solid resins packed in fixed-beds and run as plug-flow reactors. This research is, in part, motivated by the promising results of an initial test of a pretreatment process in which oligosaccharides are dissolved from corn fiber into stillage8 and the recent industrial validation of yeast that co-ferments glucose and xylose.9-11 Homogeneous acid catalysts such as surfuric acid and hydrochloric acid could be used for hydrolysis.12 They are perceived to be less expensive than enzymes but cause corrosion and must be eutralized after hydrolysis as well as properly disposed of. This adds cost..."

The abstract can be found here:

http://pubs.acs.org/cgi-bin/abstract.cgi/enfuem/asap/abs/ef050106l.html

The article refers to the use of strong acid cation exchange resins.
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Coastie for Truth Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Jul-15-05 12:12 AM
Response to Original message
1. This is exactly the creativity that impedning "Peak Oil" motivates
Be interesting to see a complete set of energy balances and material balances around this process -- but why worry -- there will be a new generation of PhD candidates coming along.

Seriously, I downloaded the acrobat files (power point with lots of flow charts) - for a first chop it looks good.
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rfkrfk Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Jul-15-05 12:04 PM
Response to Original message
2. why is $0.30 a gallon for enzimes, a problem ?
the last time I looked, wholesale gasoline
was $1.80 a gallon, or so.
Strickly as a fuel, {not as a gasoline blending agent ordered by law]
ethanol would sell for at least $1.00 a gallon.

Consider the poorer countries of the world,
less 30c for enzimes, 70c would pay for a lot of
labor, and other stuff. Keep in mind that you are
turning refuse, corn stalks, rice straw, sugarcane stalks,
into a saleable product.
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Jul-15-05 12:48 PM
Response to Reply #2
3. The cost of the enzyme is in addition to other costs.
These include:

Collection and transport of starting materials.

Labor costs

Reactor costs.

Water costs.

Heating costs.

Distillation costs.

Qualification costs.

Rework costs (if any).

Transport costs.

Sales and Marketings costs.

Seen in this light, the cost of enzymes is hardly trivial.

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existentialist Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-17-05 05:10 PM
Response to Reply #3
8. other costs
Other costs you still leave out include:

Cost of planting.

Cost of cultivating.

Cost of harvesting.

And the opportunity cost of not growing other crops on the land used for an ethanol source.
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-17-05 05:33 PM
Response to Reply #8
9. Yeah, I haven't been comprehensive.
I also note that there is not likely that there will ever be a continuous fermentation process.

For the long term, I think there are probably better ways to use biomass than to make biogenic ethanol.

That said, under certain niche circumstances I still believe that ethanol based fuels - especially for the short run - can have beneficial overall effects. Much of the cellulosic ethanol will come what is now essentially a side product, plant stalks. The use of this material may have bearing on soil depletion etc, but the emergency is now. We may have to accept some short term compromises.

In any case the matter of biomass and climate change are intertwined. Droughts or similar effects may foreclose the option before it can really be exercised.
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wuushew Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-17-05 09:06 PM
Response to Reply #9
10. You frequently mention DME as a fuel substitute
is there any literature on what the energy/land requirements would be for setting up such an industry that substitutes petroleum on a large scale? I have googled some links but many of them speak to the conversion of coal not bio-mass into DME.
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existentialist Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-17-05 11:18 PM
Response to Reply #10
11. yes, there are other efficiencies too
When ethanol is mixed with gasoline, particularly in cold weather, it helps the gasoline itself burn more efficiently, and helps both engine performance and mileage.

On the other hand, in hot weather it doesn't help a bit and tends to gum up engines.
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-18-05 05:04 PM
Response to Reply #10
14. DME is available from syn gas, a mixture of hydrogen and carbon oxides.
Syn gas has historically been made from coal but today is more commonly made from methane (natural gas) and water.

The journal to which I frequently link here Energy and Fuels gives many examples of syn gas made from various biological sources. It is almost a theme in that particular journal.

The particulars of land use/water/energy requirements will vary from case to case, from location to location. This is not tremendously different from the case with electricity production as it exists right now. Ignoring external costs (environmental, social and health costs) the competitiveness of a particular means of generating electricity varies. In some places nuclear power is not as "cheap" as coal, because coal fields are near the generation source. The same is true of natural gas, wind and other forms of electric generation such as solar, which is climate dependent.

As an example, it is worth noting that ethanol is very competitive in Kansas with crude oil. I actually have heard that today ethanol is actually cheaper than gasoline there. Ethanol is not cheaper than gasoline in the Gobi desert however - again completely ignoring external costs.

Dependence on location is much less a factor in the case of nuclear power, since the energy/mass density of nuclear fuel is so high. Nuclear fuel is "too cheap to meter," and is the equivalent on an energy/mass basis of crude oil at much less than a cent a gallon. In the nuclear case, almost all of the cost derives from the cost of the plant itself. The cost of the plant, in turn, is more closely tied to public attitudes - which are mostly absurd - than it is to actual material and engineering costs. Nuclear plants are very expensive where specious NIMBY legal strategies can create costs through delays, relatively cheap where they are built in a more or less routine and predictable way. This is the main reason that it is easy to build a nuclear plant in Finland and very difficult to build one in the USA.

The cost of energy is thus very much tied to individual choices, including the important choice of how to conserve. It simply is not true that the problems of energy cost, supply and environmental impact can be addressed by fiat or by declaring these issues to be someone else's problem. We are all involved.

That said, there are ways to technologically reduce the cost and impact of energy, for the long term. I believe that technology can learn a lot by looking for a model to the natural world. For instance, one reason we knew that heavier than air flight was possible was to observe that birds and insects could fly.

A parallel situation exists for the reduction (aka as "fixation") of atmospheric carbon dioxide to make energy storage media. Petroleum is, in fact an example of fixed reduced carbon dioxide. It is well known that DME and other fuels can be managed by hydrogenating carbon dioxide. Developing technology to repeat this process industrially may not be easy, but it is certainly possible, as we know from the existence of living things.

Many technologies are available to produce hydrogen - all with varying costs. Biomass is included. Nuclear power coupled to thermochemical decomposition devices also can work in this way. (Note: For many reasons, electrolysis sucks as a hydrogen production route.)

Someone will say, quite rightly, that my above statement implies that it is possible to use "solar only" means to provide industrial energy. This is, on reflection, certainly true, but the question - on which issues of land use/water/etc impinges is very much tied to scale. I believe that the human population is currently too high to make this a serious option now, but with a nuclear bridge, to a more sensible population size, it may be possible some day in a less stressed time.
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phantom power Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-18-05 05:29 PM
Response to Reply #14
15. How cheap (and fast) can a nuclear plant be built?
Suppose, for instance, that a few years from now, America gets religion regarding climate change and dwindling oil, etc, and decides that it wants to build an assload of nuclear plants, in a big hurry.

If people were highly motivated to do it, removing all artificial obstacles, etc, how fast could it be done? How cheaply?
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-18-05 06:24 PM
Response to Reply #15
16. From the French (and early American) experience 2 to 3 years each.
Edited on Mon Jul-18-05 06:33 PM by NNadir
A reasonable cost would be about two-three billion dollars each. As in all systems, construction costs are closely tied to the cost of money. If the United States spends and tax cuts its way into hyper-inflation - which seems to be its current program - the nuclear (and most other) options will be foreclosed.

It is worth noting that the United States designed, built and began to operate about 100 nuclear reactors in a 20 year period from 1960-1980. These reactors still today provide a very important fraction of our energy. The French built almost 80 reactors in a similar period so effectively that electricity is the 4th largest French export. Some of these reactors were very cheap. Some - almost all in the US - were incredibly expensive. Irrespective of these factors, almost all today operate profitably and at high capacity. In those days of course, we (the US) had worthy engineers, a respect for science, and a culture of realistic thinkers. Today we have a culture of worthless MBAs including the abysmal creature who occupies our White House.

The Gen IV reactor program claims that nuclear reactors can actually be built more cheaply than this figure, and perhaps more quickly. This prediction needs, of course, experimental verification.

It is worth noting, however, that the nuclear construction infrastructure is not what it used to be, at least in the US. This is somewhat offset by standardization of design, a much more complete understanding of nuclear reactor physics and engineering, the existence of a mature technology (we know what works from analysis - positive and negative - of existing reactors), and the by introduction of simpler technology like passive heat transfer systems.

In the United States nuclear engineering programs have languished from the long term effects of doublespeak. It is still, even at this late date, hammered in an almost rote fashion that nuclear energy is dead. As you know, I discuss this perception frequently.

Personally I believe that certain types of homogeneous reactors will prove very cheap and very easy to build should humanity survive long enough to employ them. These reactors do not involve the use of mechanical systems like control rod drives, etc and in many cases can be continuously fueled without shutdown. The basic idea is similar to the much ballyhooed "pebble bed reactor." Although I do not like this reactor (PBR) very much because I believe the design wastes fuel - I like reprocessing strategies - and because it is largely designed to address risks that are already acceptably low (with PWR's for instance), it probably would be a cheap technology with low start up and operating costs.
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phantom power Donating Member (1000+ posts) Send PM | Profile | Ignore Tue Jul-19-05 10:18 AM
Response to Reply #16
17. So, the effective rate depends on how many you build in parallel.
You can build one in 2-3 years, but you could also build 100 in 2-3 years, if you had sufficient resources to implement 100 projects in parallel.

Speaking purely in terms of money, we could build 100 of them for about what we've spent on the Iraq war. (so far)
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Fri Jul-22-05 11:55 PM
Response to Reply #17
18. Yes.
It breaks my heart, not just to have wasted the money in Iraq but to have wasted the money to kill and steal like common thugs.

For this much, we could have gone a long way towards building a future, just as that generation of the 1960's built a future for us.
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amandabeech Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-16-05 05:14 PM
Response to Original message
4. Would someone please put this in words accessible to
non-scientists?

Two questions:

1) What would be the estimated EROEI or net energy of this process?

2) What are the byproducts. I am particularly interested in recycling the nitrogen, phosphorus, potassium and trace elements necessary for plant growth from the feedstock.
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-16-05 07:38 PM
Response to Reply #4
5. This is research. Therefore there are many unknowns.
Edited on Sat Jul-16-05 08:11 PM by NNadir
I'll try to put it in simpler, if long winded, terms:

Polymers are giant molecules made from smaller subunits called monomers. Polyethylene for instance is a huge molecule that is a chain of a smaller (a two carbon molecule called ethene or "ethylene") discrete molecule.

Polymers are not limited to plastics made by human beings. Many living systems have polymers. An important class of such polymers are chains of small six carbon sugars.

The formation of these sugar polymers involves the removal of a water molecule. It is sometimes called "dehydration." The breaking down of sugar (and many other biological) polymers involves the addition of water molecules. It is commonly called "hydrolysis," literally "water breaking." Inside cells, hydrolysis and dehydration are effected with the use of very specific catalysts of relatively precise shapes. These are called enzymes.

There three main types of polymers of the most common sugar in living systems, glucose. These are cellulose, starch, and glycogen. The latter two are energy storage media in respectively, plants and animals. Because they are energy storage media, it is essential that plants and animals each have common enzymes that switch between the monomeric form, glucose, and the polymeric form. Such enzymes are widely distributed among almost all living things.

The difference between cellulose, starch and glycogen arise not from a difference in the monomers but in how the monomers are linked. Glucose is a three dimensional molecule: It has a "top," a "bottom" and "sides" that all differ. Plus there are different positions where the linkages can take place. There are in fact, many possible different types of polymers of glucose, but the most prominently found ones in nature are those which I have described.

Cellulose, although it requires the investment of energy to make, and thus contains (potential) energy is not primarily made cellular energy transactions. It is, instead, mainly used as a structural material which comprises wood and straw to give two examples. (The difference between wood an straw largely consist of the types and presence or absence of other types of polymers, called lignins - but all plant cell walls contain cellulose.) Enzymes that can break cellulose back into its constituent monomer, glucose, are relatively rare. In general they are only found in bacteria. In fact, in order to digest grasses, which are cellulose, the stomaches of solidungates (including horses and cows) must contain bacteria. If these bacteria die, the animal will die.

Enzymes work, in many cases, by behaving like acids. One definition of an "acid" is something that donates hydrogen ions (protons) to a molecule, causing it to insert water and hydrolyze.

Thus a brute force approach to hydrolysis of cellulose is to simply add acids, like sulfuric acid, or hydrochloric acid to wood or straw and to break it into simple sugar than can be fermented to give ethanol. With a little heat and time, this often actually works.

However, as mentioned in the paper, the simple addition of acids have drawbacks. The chief one is that they are corrosive, but another is that they represent a disposal - and therefore an environmental - problem. They must often be neutralized.

It would be nice if one could easily remove and add acids without much neutralization and separation. For many years this was not possible. But in the 1940's and 1950's chemists invented a form of insoluble acid that are known as ion exchange resins. These acids are different in that the acid molecule is itself bonded directly to a polymer, typically polystyrene. Thus instead of expensive processes like neutralization or extraction, the acid can be added and or removed simply by passing the solution over a solid material and then filtering it when desired. Such processes are superior in general because they can be made continuous. Continuous processes are always industrially cheaper than batch processes. Note that all current means of biological production of ethanol are batch processes. The manufacture of ethanol from ethene (from fossil fuel sources) is much cheaper (ignoring the external cost of global climate change) than biological methods in part because the fossil fuel process is continuous.

This is the basic idea of this paper.

Interestingly, ion exchange resins are very useful for recovering trace elements like those you mention, including potassium. In fact, many people have ion exchange resins in their home that remove calcium from their water: These are "water softener" systems. In theory ordinary water softeners could be used to "recover" calcium, if for some reason people had a need for it.

Such systems are more typically used for the removable of undesirable atoms, like lead or calcium, but they can also be used for recovery of desirable elements. The Japanese have, for instance, demonstrated an industrially scalable system for recovery of uranium from sea water using ion exchange. This process will only be economical, however, if the price of uranium rises to more than $200/kg, a factor of five higher than the current price.

Whatever the case, the paper describes of laboratory investigation. It is research, not commercial development. Whether it is useful, scalable, or economic remains to be seen. There are many unanswered and probably uninvestigated questions. It may be economic under some conditions and not others. There may be problems that prevent it from working on a scale greater than bench top. In general ion exchange resins are relatively expensive, although prices definitely are coming down. Ion exchange resins, unlike other types of acid, are reusable. They can function for many, many years with simple recharging processes.

I hope this clarifies the issues. Thanks for asking.

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amandabeech Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-23-05 12:33 PM
Response to Reply #5
19. Thanks so much NNadir.
Your translation clarifies many points for me.

I have read about the uranium extraction from seawater elsewhere (energyresources @ yahoo groups), but didn't understand how that works.
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NNadir Donating Member (1000+ posts) Send PM | Profile | Ignore Sat Jul-23-05 01:05 PM
Response to Reply #19
20. You're very welcome. I'm glad it helped.
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happyslug Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-17-05 11:32 PM
Response to Reply #4
12. Do not get hung up on ERORI when it comes to Ethanol/Bio-Diesel
Edited on Sun Jul-17-05 11:46 PM by happyslug
Remember the main concern is replacing oil in the transport role. Other energy needs of our society may be better addressed by direct use of many of the energy forms I will discuss below (For example it would probably be a more energy efficient use of plant fiber to burn directly in your fireplace than to convert the fiber to bio-diesel and burn it in your oil furnace). The main problem in the future will be transportation not heating (through the first problems with people dieing for lack of ability to get oil will be people dieing of lack of heat do to an inability to buy fuel oil for their homes during winter). Saying that lets concentrate on transportation and energy (The comments as to Ethanol also apply to Bio diesel, for both have to be produced and the only real difference is the process to get the end product NOT the fact you can use either as a fuel, the best term to use should be either Bio-energy or Bio-Fuel, for that is what we are talking about the use of energy sources based on biological crops).

ERORI (energy returned on energy invested) while important in transportation, is not the only factor to consider when considering the future of bio-energy to truly replace Oil in the transportation area. For Bio-Fuel to completely replace oil, Bio-Fuel's ERORI will have to be 1 or less (and it NEVER will be). On the other hand there places where the use of oil/Bio-Fuel type fuel is worth the excessive ERORI number. For example Ambulances, to get victims to the hospital as soon as possible. Emergency vehicles to get people out of harm's way (Which may even be helicopters which just eat up fuel).

Part of the future of Bio-Fuel will be to get the Energy used to produce the Bio-Fuel down, but the basic process of producing Bio-Fuel is energy in-efficient (i.e. the ERORI is more than 1). On the other hand the alternatives to liquid fuel are not as energy efficient from a weight to energy produced level as is oil/Gasoline/Bio-fuel. To better show you want I mean lets look at the Energy alternatives to Liquid Fuel. First is coal, while an excellent source of energy (Ignoring the pollution problems of coal) it is NOT as easy to use as oil, nor as energy powerful as oil. Furthermore the soot produced by using coal requires it to be used in much larger engines than oil burning engines (This is one of the reason you have never heard of a coal burning plane). Historically Coal has rarely ben used in internal Combustion engines (I would say never but I have heard of one or two applications that were tried and failed). Coal was used as a heat source in External Combustion engines (Ships engines and Steam Locomotives). Coal has been used to propel Cars and Trucks but all have been failures do to the size the engine has to be to be to be able to handle the soot from burring the coal (this assumes Internal Combustion engines, External Combustion engines could isolate the Coal soot).

Similar arguments can be made about Nuclear power. While the USAF did fly a nuclear generator in a B-36 bomber in the 1950s, Nuclear power has NEVER been used to propel a plane (Even the B-36 was powered by oil, the Nuclear Generator was just to test if it would interfere with flying a Plane, the Generator provided NO Power to the Plane). Generally the weight of the Nuclear Generator exceeded benefits of using nuclear power to propel the plane (Ignoring the potential problems when a plane crashes). Similar arguments can be made about the use of nuclear powered ambulances, trucks, and heavy machinery as I made about Coal powered ambulances, trucks, and heavy machinery.

Solar, wind, hydro and other "renew-ables" also can not replace oil in the transportation area. Either because they are not 100% reliable or just to heavy to use in a car. On the other hand all of these sources of energy (Solar, wind, Hydro, Coal and Nuclear) can be converted to produce electricity. Electricity can be used to directly in the transport role (i.e. after electrifying the rail lines and than the Interstates) or indirectly to provide the excess energy to convert either coal or crops to Bio-Fuel.

There is a lot of lost energy converting the various other forms of energy to electrical energy, such loses has to be accepted ed (and hopefully addressed with better technology in the future). The real problem is the lost of energy converting the electrical power to some sort of usable power for transportation. Thus the real problem is how to use the Electrical energy? The most efficient way is direct application i.e. as used on the Electrified train system of the American North East and the various Light Rail Vehicles used throughout the US. You will have the cost of maintaining the electric lines (Or third rail if a third rail system is used) but you will NOT have the lost of electrical power as set forth below.

The other two ways to convert the above Electrical Power for use in transport is either to power up batteries (20% efficient), fuel cells (50% efficient) or Fly Wheels (90% efficient, i.e. for every watt of power you put into a fly wheel you get .9 out of it) OR use the electrical power as the energy stock to convert crops into Ethanol or Bio diesel (Efficiently will depend on the crop use as the base AND the electrical power used to convert it into Bio-Fuel).

Charging Batteries just do not make sense given their heavy weight per power stored. Fly wheels, while efficient, are expensive, temperamental, and if something goes wrong deadly. Thus I see Fuel Cells being what people will be using and as you can see at 1/2 the efficiency as the same power being used directly by a LRV (And all of these power storage devices loss the ability to hold a charge as temperature declines). On the other hand ethanol is usable in winter (Bio-diesel is also usable but you have to make sure you use proper starting techniques when temperature drops below 32F).

Thus I foresee Bio-Fuel being used in the future, but not as replacement for our present use of oil/Gasoline. Can NOT happen. On the other hand some sort of Liquid fuel will be in demand. At least for winter use for emergency vehicles. I also see it being used on ultralights (where the use of such a fuel may permit someone to get someplace quicker than by riding a bike), airplanes for the Military (mostly search and Rescue as opposed to true military operations) AND use to launch satellites into space (Through this may be Hydrogen based, but derived either from Nuclear Power, Solar Power with Bio-Energy as a source stock for the Hydrogen). These "better" uses for Bio-Fuels will put a premium on such fuels and thus such fuels will exist but at very high prices. During the Bosnia War Gasoline was selling as high as $62 a gallon in one city under siege, which gives you the price I am looking at for such products).

Now I discussed the need for Liquid fuels with high ERORIs, but I also need to discuss ways to get that fuel to market. Today these crops ERORIs are high do to the high use of oil to plant, grow, harvest and transport such crops to a Bio-Energy producer. As pointed out above sooner or later transport will convert to electricity. Once Converted the issue will be getting the crop or bio-energy to the Rail head. You have two ways, animal/human propelled or Bio-Energy propel. I just do not see the later for the price will be to high. I see the former do to horses making the trip will be more efficient use of the fodder.

Within a day a Horse draw wagon can go 40-50 miles. Most places in American today are within 40 miles of a rail road track. Such horses will use the energy of the plant more efficiently than converting the plant to fuel and than using that fuel to haul the fuel. I see the same for the actual planting, growing and harvesting of crops. You will see a return to smaller farms do to the need for the farm to be small enough to be operated by a family using horses as opposed to today where to break even a farmer has to have a tractor. As the price of oil goes through the roof, farmers will convert to using horses. Many of them still have horses (at least as pets) thus the conversion will NOT be as bad as some expect (Through it will mean complete change in equipment for a horse can NOT provide the power needed to use the various plows and other attachments designed for use by a Tractor). Once the conversion is made things will settle down, but like most changes the conversion will be rough.

Now the above does NOT affect the ERORI that much, the main difference is the TYPE of energy used to produce the Ethanol. Today the above is done by tractors and trucks using oil. In the future it will be done by horses whose energy will be provided by grain and grass. It will be more energy efficient to feed the grain and grass to the horse and than use the horse as transport and to plow than to convert the grain and grass to Bio-energy and use the Bio-fuel to farm.

Thus the real question is not ERORI but the cost to produce the bio-fuel (Either Ethanol or Bio-diesel) AND who will pay the subsequent high costs GIVEN THE LACK OF AN ALTERNATIVE.

Once the farmer has converted to using the horse, the horse will have first claim on the food produced by the farmer. Once the farmer's family is feed than the excess crops will be transported by horse to the nearest railhead. The crop will be sold both as food and as a source of liquid energy.
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dcfirefighter Donating Member (1000+ posts) Send PM | Profile | Ignore Mon Jul-18-05 04:24 AM
Response to Reply #12
13. 1880's technology
Edited on Mon Jul-18-05 04:26 AM by dcfirefighter
isn't quite a step forward.

There are plenty of alternatives to horse & buggy culture:
www.carfree.com
www.skywebexpress.com
www.tdi.uk.com/Ultra%20Light%20Rail%20Minitram.htm

urban cores (re)built around several transit technologies can use grid power for intracity people and freight transport. Electric trams can also use short 'booster' wires to accelerate from stops, coasting between stations, with a battery for 'limping' in after emergency stops.

No farmer wants to spend two days moving his harvest from field to rail. At the ranges you speak of, battery power isn't out of the question. The fast lane of the Interstate Highway System could be converted to rail as well. Ideally, much more food will be grown nearer where it's consumed, perhaps suburban lawns will be replaced with cropland & market gardens.

I've seen several sources putting the output of open aerated algae ponds at 10-20,000 gallons biodiesel per acre, per year. This requires water, but can use salt water (though I imagine saltwater might accelerate the depreciation of equipment). Transport fuel could be used at current power usages on ~5% of the land area we use for grazing (though it would certainly benefit from being located next to urban wastewater plants rather than in rural Utah). I suspect that by the time such a plan began to see effect, the individual power usage would be down, but the increase net power usage will make up for the difference. I see no practical means for reducing transport fuel use without raising the cost of transport fuel.
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Broca Donating Member (524 posts) Send PM | Profile | Ignore Sat Jul-16-05 11:08 PM
Response to Original message
6. More on the drawbacks of the conventional methods of
Edited on Sat Jul-16-05 11:11 PM by Broca
ethanol production:

http://www.biologynews.net/archives/2005/07/05/ethanol_and_biodiesel_from_crops_not_worth_the_energy.html

I have a state assemblyman who at the bequest of the farm/corn lobby is pushing a bill to mandate the use of more ethanol from corn. Of course taxpayers subsidize the corn crops. Interestingly he touts free enterprise and capitalism. I guess mandating and subsidizing is the new capitalism.
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Coastie for Truth Donating Member (1000+ posts) Send PM | Profile | Ignore Sun Jul-17-05 09:02 AM
Response to Reply #6
7. Berkeley former EE Prof Bill Wattenburgh had Patzek on his show
on San Francisco's KGO - and tore Tad W. Patzek a new one. I have read the Pimentel and Patzek studies.

First, these studies make some "assumptions" in their comparisons with fossil fuels -- where corn based ethanol competes from "zero base" that even includes the sunlight as a cost (hint - photovoltaic can only use the ultra violet - so I am not sure how they get where they are going by including all sunlight).

Second, they make some assumptions about the state of the technology.

Third, I heard Tad W. Patzek on Ronn Owen's show, on KGO. I called in - asked him some questions about the study. Glib but faulty.

PS - I have worked in alternative, renewable and green energy (including Fischer-Tropsch, photvoltaics, high energy density batteries, fuel cells, and co-gen and distributed systems integration, and even nuke power). Yes, I do have publications (this is the latest edition, the edition I did was the earlier red bound edition)

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