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Is Ethanol the Answer to the Energy Dilemma?
n0xin writes "According to Fortune, "The next five years could see ethanol go from a mere sliver of the fuel pie to a major energy solution in a world where the cost of relying on a finite supply of oil is way too high." In an effort to meet fuel-economy standards, automakers already have 5 million ethanol-ready vehicles on the road. Supporters are optomistic that "we can introduce enough ethanol in the U.S. to replace the majority of our petroleum use in cars and light trucks." Are SUVs included in this category?"
Yes, the government tallies SUVs under that "light trucks" category, because they are (or used to be) built on truck frames. The only difference was they had cabs that went all the way back.
Ethanol would take up too much of our ag land that we need to sustain our food supply. Check the movie The End of Suburbia (http://endofsuburbia.com/ for a preview of our sad future.
It looks like there's finally a use for all the grass clippings coming out of suburban neighborhoods and non-office paper that gets thrown away instead of being recycled.
From the article:
Instead of coming exclusively from corn or sugar cane as it has up to now, thanks to biotech breakthroughs, the fuel can be made out of everything from prairie switchgrass and wood chips to corn husks and other agricultural waste.
This biomass-derived fuel is known as cellulosic ethanol.
Ethanol made from plants will form a closed carbon-cycle. Ethanol sythesized from non-fossil sources will form a closed carbo-cycle.
It also reduces the amount of Sulfur release, reducing acid rain. As acid rain has contributed to the deforestation of Scandinavia quite considerably, a reduction in atmospheric Sulfur may allow these to grow back and over time photosynthesis some of the CO2 back to Oxygen.
The only reason some people get lost in thought is because it's unfamiliar territory.
Ethanol fuel is made of corn. Corn is grown using industrial processes which rely heavily on oil-based fertilizers and oil-fueled machinery. A much better solution is hemp-oil.
could it be?
These are all over the place here in Brazil. Last I heard, something like 80% or 90% of small cars were sold with hybrid ethanol-gasoline engines (nicknamed Flex around here). Many shops (even small ones) already have the technology to convert an ordinary gasoline engine to a hybrid, and it isn't that expensive either.
I should remark that Brazil was a pioneer in the usage of ethanol for car fuels, but in the last decade or so it was getting out of fashion. With the advent of hybrid engines we're seeing a revival of sorts, particularly given the lower price (which unfortunately has been rising though).
For my part, I believe the future is biodiesel, not ethanol, though.
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Ethanol need not be produced from corn...From TFA:
Cellulosic ethanol requires little far machinery and no pesticides. From Renewable Energy Access:Between its lesser environmemtal impact (up to 80% reduced emmisions) and its cost-efficiency, cellulosic ethanol is far more environment-friendly than fosil fuels.
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Regardless of what crop is used to produce it, ethanol requires areable land, and lots of it.
To produce enough ethanol to sustain the US alone, would require hudreds of thousands of acres of crops. Regardless of the sustainability of the crops, it is a huge management issue in and of itself to control all that production.
Hydrogen, on the other hand, can be produced readily in a power-plant type fashion.
A look at a small table of energy return on energy invested figures gives ethanol from corn a 1.3, ethanol from sugarcane something like 0.8 to 1.7 (meaning it could possibly be a net energy loser!), and ethanol from corn residues 0.7 to 1.8. Compare that with petroleum's EROEI, which is today something of the order of 23, and had once been higher than 100. Even at the maximum efficiency level, it would probably take dedicating all of the arable land in the United States to grow corn for conversion to ethanol to allow business as usual. Also, mechanized farming techniques are so heavily dependent on petroleum-based (and natural gas based) fertilizers and pesticides. Here's a good article on how to properly evaluate these schemes for alternative energy, and ethanol doesn't fare very well.
No, the only real solution to the energy crisis is to abandon the grossly wasteful American way of life, and take steps towards serious conservation efforts.
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Ford's ethanol hybrid
To produce enough ethanol to sustain the US alone, would require hudreds of thousands of acres of crops.
Want a ballpark figure? 640 000 acres = 1 000 square miles. That's smaller than the State of Rhode Island (1 545 sq.mi)
I agree on all counts but I would add that there are other sources for ethanol than corn and some grow on arid land. One issue that's rarely discussed is that a lot of land is growing government subsidized crops that are essentially unneeded. If the land was used instead for ethanol or oil crops there would be a net gain. So long as the farmers get their subsidies they don't care what they grow. The problem usually comes down to a lack of communication between government departments. Much of the government opperates like warring camps competing for financial resources. If there was more cooperation in the government many of these problems would go away. Alternative sources are taboo because the oil companies are threatened by them. If it was simply a matter of wanting to stay on the oil standard we'd be romancing Canada for oil sand oil but the government has been ignoring the largest known source of oil. Why? Domestic oil companies have no control of that source. By invading Iraq we gained control of one of the largest current sources. It helps keep the domestic oil companies in control of the money. I hate to see the oil sands become the answer because that means a drastic increase in global warming. I hate the term global warming because it's deceptive. It's climate destabilization in truth. Notice the record cold and snow falls in Hawaii that no one in memory can remember seeing? It's part of the same effect and the global warming models predicted it. Everyone shouldn't be afraid of global warming it's the backlash which is global cooling that should make people afraid. Remember during the last round half of the US and virtually all of Canada was under an ice sheet. Europe is scared. Why aren't we? Just how many record hurricanes do we need in a year before some one wakes up and smells the CO2?
Of course, oil isn't energy positive either.
Okay, sure it's energy positive from the time we extract it from the ground, but any fair consideration needs to take into account the amount of energy that, once upon a time, was required to create that oil, since essentially what we're required to do is replace the whole supply chain (or, wait a few hundred thousand years -- or more! -- for the supply chain to replenish the stocks we've taken).
I'm led to believe that the figure is approximately 24 tonnes of plants to produce one litre of petrol as an end product. Considered this way, then ethanol, biodiesel or hydrogen are all far less energy negative.
The bonus is that waiting several hundred thousand years for the fuel supply to renew itself isn't necessary with the other energy-negative part-solutions.
Oh, and converting a standard four-stroke petrol engine to run on ethanol is not that hard, either -- as proven by a recent entry of a 1925 Austin in the Darwin to Adelaide Panasonic World Solar Challenge. Bigger carburetor jets (or similar adjustments in a fuel injected vehicle), cylinder head lubricant (probably not necessary on most unleaded vehicles), and some timing adjustments are about the mix of it, and come to think of it EFI systems could be designed to handle such adjustments mostly automatically.
Cellulosic ethanol is ethanol derived from cellulose.
..... this does not seem to offer any advantage over the use of a dilute acid.
The idea is simple. You take any plant matter containing cellulose {a long chain polysaccharide which is fairly immune to yeast}, and hydrolyse the cellulose into mono-, di- and short-chain polysaccharides. Then you have something that will undergo fermentation.
Any dilute acid will hydrolyse cellulose, but then you have the problem to get rid of the acid {which will harm the yeast} without creating a salt which also will harm the yeast. {Might it be possible to use a base whose salt with the chosen acid is insoluble in water, and filter out the precipitate? Since solubility is affected by temperature, it should be possible to refrigerate the mixture in the neutralisation tank to help it precipitate, and dump the waste heat into the hydrolysis tank to speed up the reaction. Further Work Required.} Alternatively, there may exist enzymes which will decompose cellulose into sugars and starches. If these are found to be compatible with yeast it may be possible to work a single-stage conversion, otherwise it will be necessary to do a multi-stage process, neutralising the first enzyme before fermentation
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