

Is Ethanol the Answer to the Energy Dilemma? 342
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?"
SUVs (Score:2, Informative)
No (Score:3, Informative)
Very interesting (Score:4, Informative)
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.
Wrong. It could. (Score:5, Informative)
Re:Still doesn't (Score:4, Informative)
Costs more than it delivers (Score:1, Informative)
Re:Ethanol seems best (Score:5, Informative)
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.
Re:No it's not (Score:5, Informative)
Ethanol need not be produced from corn...From TFA:
Cellulosic ethanol requires little far machinery and no pesticides. From Renewable Energy Access [renewablee...access.com]: Between its lesser environmemtal impact (up to 80% reduced emmisions) and its cost-efficiency, cellulosic ethanol is far more environment-friendly than fosil fuels.
You forget one factor... (Score:3, Informative)
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.
Energy Return on Energy Invested (Score:5, Informative)
A look at a small table [eroei.com] 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 [fromthewilderness.com] 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.
Like this Ford? (Score:2, Informative)
Hundreds of thousands of acres vs Rhode Island (Score:4, Informative)
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 [google.com]. That's smaller than the State of Rhode Island (1 545 sq.mi) [google.com]
Re:Like this Ford? (Score:3, Informative)
Re:No (Score:3, Informative)
Other sources of fermentable materials is currently being reasearched. Some of the sources that have been researched range from various types of trees such as birch and spruce to food processing wastes like chicken and fish entrails. The bottom line is that ethanol is a viable source of alternative energy.
Re:Still doesn't (Score:5, Informative)
Re:Ethanol seems best (Score:3, Informative)
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 [eurekalert.org]. 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 [ninemsn.com.au] 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.
Re:Who are the supporters? (Score:3, Informative)
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
Re:No (Score:4, Informative)
The stalks aren't made in to feed, the seed is, again for the same reason - low carb content. And I really hope you mean the cob and not the stalk, because if you've ever driven by a corn field you can clearly see that they don't even bother to pull up the stalk.
The production of EtOH has been increasing, but the appropriate question to ask is would it be cheeper than gas if the EtOH subsidies were removed. It wouldn't have two years ago, but we may be getting close to the point where it is now.
However, if a farmer is going to sell a portion of his crop to EtOH production, that is all it would be used for.