Ethanol. It seems so simple now.

Great Debates
21

[QUOTE=FrantzJ]
Free energy is impossible.
[/QUOTE]

Not free, just renewable. All hydrocarbon fuels are essentially solar energy in liquid or solid form – “free” in that sense. Fossil fuels store the energy the sun radiated millions of years ago, which makes them non-renewable – once the Earth’s (or any particular country’s or region’s) supply of coal or petroleum is gone, it’s gone. Ethanol, made from recently harvested plants, stores the energy the sun is radiating now, and more plants can be grown and harvested indefinitely. If ethanol is being used in ethanol production (i.e., if ethanol is used to fuel the farm machinery that grows and harvests the crops, and the trucks that carry them to the ethanol plant, and the trucks that distribute the ethanol to the point of use), that brings ethanol that much closer to being a truly renewable, sustainable resource and a practical alternative to gasoline – provided the amount of ethanol produced, minus the amount burned in the production process, is still large enough to be worth the trouble.

22

[QUOTE=kanicbird]
One big issue about widespread ethanol is you are competing directly with food.
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I believe it can be made from the inedible parts of crops – stalks, husks.

23

The problem is that , while solar energy falls onto the growing plant and is responsible for energy being stored there in chemical bonds, biomass is pretty inefficient compared to other ways of converting solar energy into usable form. Even if you take all of a crop and burn it and use the result, my impression is that it’s still not as good as the circa 18% you get from silicon photocells. The reason that coal and oil are such good sources of energy is that you’re using the end result of hundreds, thousands, or more years of stored-up low-efficiency solar energy conversion.

using the waste parts of corn to generate ethanol or methane or whatever and using the result as power strikes me as a good idea, but I’m under the impression that you really do need to use the edible corn part for ethanol conversion – that’s where the bulk of the sugar is that gets fermented into ethanol.
I haven’t seen anyone do a detailed calculation (I haven’t read the documents linked to above), but my gut feeling is that between the petrochemical fertilizers (and maybe de-weed and de-pest), and the power used to plant, water, harvest, and process the corn, it’d be hard to get more energy out of the crop in the form of ethanol than you put into it on your own accord. You’d need to soak up and efficiently convert a lot of sunlight.

24

[QUOTE=CalMeacham]
using the waste parts of corn to generate ethanol or methane or whatever and using the result as power strikes me as a good idea, but I’m under the impression that you really do need to use the edible corn part for ethanol conversion – that’s where the bulk of the sugar is that gets fermented into ethanol.
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That’s what I was thinking. There’s a reason we eat the corn itself and not the stalks. :slight_smile:

Yep. Comparisons w/ Brazil are a bit misleading since that country uses only a small fraction of the amount of fuel that the US does (IIRC, < 10%). There are still a lot of technical advances that can help make ethanol better, but I don’t get the impression we’re quite there yet. And I’d hate to have the government pick that solution as the one we’re going to get behind rather then letting competition pick the best solutions, as there is almost certainly more than one way to skin this particular cat.

25

[QUOTE=BrainGlutton]
I believe it can be made from the inedible parts of crops – stalks, husks.
[/QUOTE]

The inedible parts are often returned to the soil though, thus helping to replenish its nutrients. So even if we don’t directly compete with ethanol for nutrients, we do compete indirectly.

26

Ethanol works for Brazil, because of a unique confluence of factors 9tropical climate, huge surplus of sugar cane, and people who drive cars with 1 liter engines). this is not relevant to the USA. making ethanol from corn syrup is inefficient, and is just done to please Archaer-Daniels-Midland, and Catghill. My question: why don’t we make crude oil the same way as nature does it? We take the garbage output of NYC-and dump it into a 3000-foot deep quarry. As the garbage compresses, we supply some heat (we could have heating coils at the bottom, fueled by methane gas from the waste. We pile millions of tones of garbage into the pit-and the pressure at the bottom starts making-crude oil! basically, we get rid of garbage, and get oil at the same time! :eek:

27

[QUOTE=ralph124c]
We take the garbage output of NYC-and dump it into a 3000-foot deep quarry. As the garbage compresses, we supply some heat (we could have heating coils at the bottom, fueled by methane gas from the waste. We pile millions of tones of garbage into the pit-and the pressure at the bottom starts making-crude oil! basically, we get rid of garbage, and get oil at the same time!
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Assuming you’re not being facetious, I think this would take a lot of energy to achieve, and be somewhat complicated by the approx 18,485,325 different chemicals (some of them extremely toxic) that your giant garbage reactor would produce. It would be quicker and easier to just feed it into a combined heat & power incinerator.

28

[QUOTE=Mangetout]
The bulk quantity may be comparable, but if the mash has been used to produce ethanol, that must mean that some of the food value in it has been removed; that’s not to say it isn’t, overall, more efficient to get two uses out of it than one (and it’s certainly more efficient than simply throwing the mash away), but you still can’t get something for nothing.
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The only thing they take out is the starch, which is converted to sugar during the fermenting process. The rest of the nutrients stay in the exhausted mash. Corn was once seen as a great “fattener” of cattle because of the starch, but beef producers have moved toward leaner beef to meet market demand. That doesn’t mean skinny steers, of course, but whatever marbleing fat is required can be obtained through other additives – which, if I understand correctly, are byproducts of still other ag/industrial processes.

I also want to address the concern of “competition for food.” Hundreds of thousands of acres of good farmland are held out of production each year to keep prices (especially of corn and wheat) from dropping too low. We just don’t need that much stuff right now. Remember, too, the USDA doesn’t exist primarily for the benefit of farmers, but for the benefit of consumers – to make sure we don’t pay too much for our food. The balancing act is to keep commodity prices low enough that consumers aren’t hurt, but not so low that farmers abandon a crop as unprofitable. Finally, the amount of corn being used for ethanol is miniscule compared with the amount being used for food – and most of that is for animal feed, which, as we’ve already discussed, is now a second use for ethanol corn.

29

[QUOTE=BrainGlutton]
I believe it can be made from the inedible parts of crops – stalks, husks.
[/QUOTE]

inedible to man does not mean inedible to animals that man eats. Also economics comes into play, yes you can make fuel with switchgrass, but as demand grows are you as a farmer more likely to sell your corn for human consumption for $3/unit or to ‘Big Ethanol’ for $5/unit? This should drive the price of food much higher.

30

[QUOTE=JThunder]
The inedible parts are often returned to the soil though, thus helping to replenish its nutrients. So even if we don’t directly compete with ethanol for nutrients, we do compete indirectly.
[/QUOTE]

This was one of the things that was vaguley bugging me when I posted the OP, but it wasn’t at the forefront before I saw it written down. Using the by-product of the crops would tend to increase demand for fertilizer, which at present uses petro-products to produce.

I knew this wouldn’t be an easy solution. But like many things, it sure looks good on paper. Devil in the details and all that.

I’m thouroughly enjoying this thread and the ideas in it by many. Again, I figured this wasn’t the golden egg, but the idea is intriguing enough to want to learn about the possibilities.

Thanks again for all the info so far.

31

[QUOTE=CalMeacham]
The problem is that , while solar energy falls onto the growing plant and is responsible for energy being stored there in chemical bonds, biomass is pretty inefficient compared to other ways of converting solar energy into usable form. Even if you take all of a crop and burn it and use the result, my impression is that it’s still not as good as the circa 18% you get from silicon photocells. The reason that coal and oil are such good sources of energy is that you’re using the end result of hundreds, thousands, or more years of stored-up low-efficiency solar energy conversion.
[/quote]

Another reason is that we use a lot of machines that require hydrocarbon fuel. Ethanol can compete with gasoline. Electricity can’t, not until somebody invents a storage battery that can allow an electric car to go 200 or 300 miles without recharging, plus an electric motor that provides the kind of pickup and horsepower to which motorists have become accustomed.

32

[QUOTE=BrainGlutton]
not until somebody invents a storage battery that can allow an electric car to go 200 or 300 miles without recharging, plus an electric motor that provides the kind of pickup and horsepower to which motorists have become accustomed.
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Don’t forget a battery that can be recharged in less than 2 minutes. I realize that 200-300 miles is all many want to drive at any given time, but I’m on a serious road trip 300 miles is just the warm-up for the day. Convenience is a huge factor.

33

[QUOTE=duffer]
Don’t forget a battery that can be recharged in less than 2 minutes.
[/QUOTE]

Oh, that’s not a problem, if the battery is modular, standardized in most or all models of e-cars, and easily removable. “Filling” stations would simply have a bank of batteries on the recharger. Stop in and swap out your battery for a fully charged one.

34

[QUOTE=Gorsnak]
“Free energy” has absolutely nothing to do with ethanol. The energy in ethanol comes from the sun. The corn or sugar cane or whatever synthesizes carbohydrates from CO2 and H2O in a process called photosynthesis. It’s not a magic perpetual motion machine. Sheesh.
[/QUOTE]
The sun represents a perpetual energy machine. The more efficient the conversion the better. Right now we’re not trying to be more efficient but more convenient. The immediate need is to supply energy to technology that already exists using distribution systems that already exist.

[QUOTE=antechinus]
My understanding was that the problem with ethanol production is also that land, nutrients and water are required to make the stuff. This means ethanol production is in direct competition with food production. There is not enough land/water/sun/nutrients available for it to replace oil as fuel. Though, based on the economics, it can suppliment to a small extent.

Keep in mind ethanol has a lower energy density than petroleum based fuels.
Gasoline 44 MJ/kg
Diesel 47 MJ/kg
Ethanol 22.6 MJ/kg

also note:
Compressed Natural Gas (700 bar) 54 MJ/kg
LPG 34 MJ/kg
and there is lots of that stuff around.
[/QUOTE]
Ethanol also drives mileage way down which means a greater amount of CO2 per mile driven. I think we would be better off gasefying coal to make diesel fuel.

[QUOTE=duffer]
Don’t forget a battery that can be recharged in less than 2 minutes. I realize that 200-300 miles is all many want to drive at any given time, but I’m on a serious road trip 300 miles is just the warm-up for the day. Convenience is a huge factor.
[/QUOTE]
There are capacitor batteries that do just that. I’ve seen them demonstrated on power tools. They can be recharged in minutes. Don’t know if they are practical due to size limitations but they are very light weight.

35

Yeah, but the difference is that you can’t plant hundreds of acres of photocell seeds and stand back and watch them grow. Solar electric panels just don’t scale well. It would be totally impractical to build enough of them to power the entire country. And they also have the problem that they only produce power when the sun is shining. Ethanol crops just need average sunlight, and then after they are processed the energy is collected in a condensed form that can be used for any purpose.

[QUOTE=Magiver]
Ethanol also drives mileage way down which means a greater amount of CO2 per mile driven. I think we would be better off gasefying coal to make diesel fuel.

[/quote]

Except that the CO2 released from ethanol burning is CO2 that was recently captured in the crop. There is no net CO2 increase in the atmosphere. With coal, you are releasing CO2 that has been trapped for millions of years, which increases the current CO2 concentration in the atmosphere.

Capacitors are great for rapid release of energy, but the quantity of energy they can hold is relatively low. New technologies like nanotube capacitors may increase that dramatically, however. Still not enough to replace batteries, but enough that you could use a capacitor in your car to provide peak power for better acceleration.

As for ethanol, I’ve always been a skeptic, but I’m slowly changing my mind. There are some advances coming along that may make ethanol much more useful. Cellulosic ethanol is difficult to extract energy from, but new bio-engineered microbes may be able to do the initial breakdown and cut energy costs of production dramatically. At least one company is working on a bio-engineered ethanol crop that, at the end of its growing cycle, begins to break itself down into an intermediate that requires much less energy to produce ethanol from.

Honda sees Possible Ethanol Breakthrough

Bioengineered bacteria turns paper sludge into ethanol

Redesigning life to make ethanol

Redesigning crops to make fuel

Personally, I don’t think there’s one ‘magic bullet’ that will solve our energy needs. We’re not moving to a ‘hydrogen economy’, or an ‘ethanol economy’. Rather, we’re going to see diversification. Flex-fuel vehicles that can burn ethanol, gasoline, or other fuels. New car platforms that come in two parts - a modular hybrid drivetrain that contains batteries and motors, and a power unit that can be anything from a hydrogen fuel cell to a flex-fuel engine to more batteries for full electric operation. We won’t stop using gasoline - we’ll just start displacing it with alternatives until the demand for it drops enough that it becomes viable again, and a new economic balance will be reached with gasoline and oil making up a smaller percentage of our fuel usage. Over time, as non-renewable resources become more scarce, their price will rise and more alternatives will take over until we reach another equilibrium. Etc.

The new technologies that are here today - hybrids, plug-in hybrids, nuclear power, and ethanol, are the building blocks of a new diversified energy economy. Maybe hydrogen will make the grade, maybe it won’t. Wind power will join the mix in some small percentage, as will solar. New breakthroughs in solar cells from nanotubes may move solar up the ladder as time goes on, but the beauty of a diversified energy economy is that the ratio of the mix of energy supplies can then change gradually in response to market demands. If the price of electric power drops and the quality of batteries improve, more people will opt for the all-electric option in their cars - no infrastructure or major manufacturing changes needed.

36

[QUOTE=CalMeacham]
… the circa 18% you get from silicon photocells …
[/QUOTE]
We’re getting 30% now.

37

In laboratories they’re getting more than that. But 18% is a pretty average value.
Sam I don’t have the numbers, but I suspect you can get more usable power from a “farm” of photocells than a farm of etrhanol. And they don’t deplete the soil.

38

[QUOTE=CalMeacham]
Sam I don’t have the numbers, but I suspect you can get more usable power from a “farm” of photocells than a farm of etrhanol. And they don’t deplete the soil.
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Bold mine. While I don’t know if they do or don’t deplete the soil, one thing is for sure it has a effect. You are preventing energy from reaching the ground. Does it make a difference, well at first glance it doesn’t seem to, but such effects can’t be entirely rulled out either.

39

Actually, METHANOL (wood alcohol) is a better choice for the USA. methyl alcohol can be synthesized from natural gas, or wood or coal. Its a better fuel than ethyl alcohol, and can also be blended with gasoline. Methanol solves another problem-the alcoholics in Brazil buy a lot of fuel to drink-methanol is fatal, so no unauthorized, non-vehicular use problems.

40

[QUOTE=Sam Stone]
Personally, I don’t think there’s one ‘magic bullet’ that will solve our energy needs. We’re not moving to a ‘hydrogen economy’, or an ‘ethanol economy’. Rather, we’re going to see diversification.
[/QUOTE]

It does seem like we are moving towards diversification, but there may be a return to a single fuel which could be readilly made from vastly different energy sources. Perhaps this will be hydrogen, chemical battery storage, ethanol, or something else.

It just doesn’t seem to make sense to have a car that can run on gas, hyrodgen, electricity, diesel, CNG, ethanol. Yes there are single engines that can run on any of these fuels (well except for electric - but then again external combustion could use electric or even nuke power to produce heat to drive the thing), but take a look at what’s needed and how you store the fuel(s) onboard and I think it’s obviouse that at best a car will only run on a few fuels with simular properties, including the state of matter (liquid vs compressed gas).

Also I just can’t see filling stations will all different fuels available. It’s currently hard enough to tell how much gas is where there is 3 grades + diesel + kero, now add to that the price per cubic feet of CNG and H2, Add to that E-85 and eventually E-100, and the price per KW-H, how can one compare which is the fuel to get?