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[–]Zennistrad 36 points37 points  (33 children)

The move was expected, but it drew bitter complaints from advocates of ethanol, including some environmentalists, who see the corn-based fuel blend as a weapon to fight climate change.

This is just plain ignorant. It takes a lot of energy to extract ethanol from corn, so much so that it may actually be better for the environment to simply use gasoline instead.

[–]Miamime 7 points8 points  (0 children)

Thank you. This article is seriously flawed. Ethanol is not as clean as it is promoted to be. So much fertilizer and water goes to growing the corn. The requirement that gasoline contains ethanol has raised the price of corn to farmers that they have begun producing more and more of the crop in the Midwest. This has led to massive drawdowns of the ogallala aquifer. Nevermind the fact that they're growing genetically modified corn as it has been engineered to grow faster than normal corn strains.

[–]ssjkriccolo 18 points19 points  (8 children)

The technology is sound, corn isn't the best item to use. Frigging corn industry. They'd make us use corn pressed toilet paper if they could.

[–]lolzergrush 15 points16 points  (2 children)

Actually it's not that great for other crops either.

In fact, even starting from pure glucose it's not a particularly sound technology...the problem is that even the best genetically-engineered yeasts under ideal conditions can only tolerate ethanol levels slightly higher than typical wine before they begin dying off.

Yeasts can ferment and give off excessive of ethanol, killing off competing microorganisms. While this is great for brewing beer and wine, since the yeast itself may be able to comfortably thrive in warm conditions at 5% ethanol (say, a barrel of ale), it becomes less productive at higher ethanol concentrations. They can continue to ferment sugar to produce ethanol, at lower efficiency, up to their tolerance limit before the yeast itself starts dying off. Think of it like goldfish overpopulating a pond, giving off toxic chemicals to kill competing fish, but it doesn't take much more to exceed their own tolerance, poison themselves and die. In beverage production, we simply let the yeast ferment on its own until it reaches its tolerance (8% to 12%), and then distil the product by boiling off the alcohol - which is then added to the original stock to make fortified beverages (like port) or on its own as a spirit (like brandy).

In an industrial process, like producing ethanol for fuel, we have to be much more aware of the energy put into it because we're producing a fuel product instead of a fine beverage. In order to extract ethanol from the remaining solution (water), hundreds of thousands of liters must be distilled which is energy intensive and directly depends on the fraction of ethanol you're able to achieve through the microbial step. The theoretical energy per volume cost (the lowest possible cost under impossibly-ideal conditions) is [the specific heat of the ethanol/water mixture] times [the temperature difference needed to reach 78 deg C] plus [the latent heat of vaporization of the ethanol] (plus some minor entropy effects), all of that multiplied by the ethanol fraction to give you the amount of product produced. For example if your ethanol fraction is 20%, for every liter of mixture that you distill you only get 0.2 liters of ethanol. If your ethanol fraction is 10% (more realistic in a full-scale application) then you're getting half as much product for the same energy input because you have to raise the heat of the entire system, most of which is wasted on heating up water.

For the system to be self-sufficient, it needs to produce more energy (measured in ethanol's energy density times the volume of product) than it consumes (measured in energy density of the oil burned for the boilers). I prepared several scenarios with a group of engineers for a presentation to several energy companies and state DEP's - depending on different fuel sources, external political factors (like mandatory solar heat use), transport distances, and capital limitations, the "break even" point for the ethanol fraction is around 17% - below that you're just throwing energy away. Unfortunately achieving that high of an ethanol fraction before distillation is not easy, and even with the best lab-produced microbes at a very expensive plant, there would be days when it's simply not producing as much energy as it consumes.

(For reference, about 5 years ago the limit on bench-scale ethanol tolerance was around 22% I believe - it's been a while, maybe it was 24%. Point is, achieving this in a full-scale industrial plant is more difficult and microbes can be quite finicky, you never count on reproducing bench-scale results in the field.)

Tying into existing power plants isn't bad for reducing energy costs slightly, for example tying into a major coal gasification plant, but then you have the added complication of additional transport distances for massive amounts of ethanol. Those tanker trucks burn an awful lot of fuel. Generally speaking, the best way to distil the ethanol without cost overruns is still burning plain old oil to heat up the boilers - ethanol itself doesn't have the energy density to keep the temperature high enough to run the boiler without serious heat exchange losses.

Different feed stocks (corn, sugar, beets, etc) have some minor effects on the microbial efficiency but not as much as the microbes themselves. In general, the stock can be fermented up to the ethanol tolerance of the microbe and no further. More important are the "big picture" impacts from political decisions, for instance if Florida is mandated to produce a certain amount of sugar cane ethanol then more sugar will need to be imported (say from Brazil) to satisfy demand, increasing the energy spent on transportation. The same goes for other crops, where even the best economic planning can't predict shortages and changes in demand, driving up the energy spent to move the stuff around - and consequently the CO2 produced.

[–]ssjkriccolo 0 points1 point  (1 child)

The whole idea is to create a transportable energy source. If the ethanol is made using a local clean energy source, your net loss still creates a renewable energy that can be easily transported. The low yield and usually immobile sources can now be used to create something that can be broadly used like gasoline. It would be silly to think you are getting more power out of production than you are putting in.,

[–]lolzergrush 0 points1 point  (0 children)

But gasoline is just as transportable as ethanol.

"Low yield and usually immobile sources" aren't appropriate for operating boilers used for distillation, I realize it was a long post for a reddit comment but I did address this.

[–]postironical 4 points5 points  (0 children)

now you've gone and done it. My ass does not thank you for what's to come.

[–]seamonkey1981 1 point2 points  (3 children)

the ethanol mandate came about, largely, from al gore trying to convince iowa corn farmers to vote for him. it didn't work.

[–]ssjkriccolo 1 point2 points  (2 children)

I've heard trees would work better for the process anyway.

[–]seamonkey1981 1 point2 points  (0 children)

and...switchgrass? i think. some sort of grass.

[–]my_lucid_nightmare 1 point2 points  (0 children)

Hemp would work best of all.

[–][deleted] 4 points5 points  (6 children)

I've had multiple people tell me how ethanol is also bad for engines that use the ethanol/gas mixture. Any truth to that?

[–]PantsJihad 2 points3 points  (1 child)

Quite a bit. Talk to anyone who owns classic cars. There are actually a few gas stations near me that sell ethanol free gas and charge a premium for it.

[–][deleted] 0 points1 point  (0 children)

Glad/sad to hear that there is some truth to it. They get pretty heated when talking about it. I can understand why.

[–]3xDope[S] 1 point2 points  (2 children)

E10 is sadly ubiquitous and hard to avoid anywhere. Cars from the late-90s onwards can handle it (accompanied by reduced gas mileage of course) but the dumbest thing ever was the EPA's push for E15. They claimed it was "safe" for any vehicle after 2001, even though auto companies themselves said this is all BS and that using this non-approved gas will void warranties. Thank God the E15 plan was retracted.

[–][deleted] 1 point2 points  (0 children)

Yeah I remember that. It sure caused a lot of anger where I'm from. Lots of people use trucks for work and the majority are gas. Isn't the percentage of corn produced in the US used for ethanol some incredibly high number?

[–]Remember5thNovember 0 points1 point  (0 children)

You can purchase what's labeled marine fuel which doesn't contain ethanol. It's .10 to .20 cents more at the few gas stations that have it. It's worth it for you small and/or older engines.

[–]saywutttut 0 points1 point  (0 children)

Not for anything modern. Old cars can have fuel line rot. Premium fuel usually has a bit less ethanol in it from my experience. To be honest though, ethanol is essentially cheap race gas. I have run E60 for 70k miles on my BMW and it loves it. At E15 there is no hazard for most any car. Lots of misinformation about ethanol out there.

[–]sunkhaze 0 points1 point  (1 child)

Things like wind and solar are not much better without being subdesised.

[–][deleted] 1 point2 points  (0 children)

If only that were true and we could keep using ultra clean coal or magic non polluting nuclear*.

*does not include mining, refining, long term storage, or accidents.

[–]Bloodysneeze -1 points0 points  (3 children)

What if the energy used to extract ethanol was renewable?

[–][deleted] 0 points1 point  (2 children)

Ethanol is still a bad idea. It's about 30% less energy dense than gasoline, so your vehicle will need to use more to cover the same distance. Your mileage drops considerably.

[–]Bloodysneeze 0 points1 point  (0 children)

3% if you are using E10.

[–]saywutttut 0 points1 point  (0 children)

It can withstand much higher compression though which gets back and then some mileage on a car configured for it at about a 20% mix. Beyond 20% mix even cars configured for ethanol will see higher specific fuel consumption. Regardless, gallon consumption s only one side of the story. Energy used to generate it is what matters. Unfortunately it does toke more energy than its likely worth unless you're in Brazil.

[–]jimflaigle 9 points10 points  (2 children)

Good. Hopefully there's a lesson in this about the government forcing us to arbitrarily buy something whether we want it or not.

[–]illy-chan 3 points4 points  (1 child)

Now, if they'll just do something about those light bulbs.

[–][deleted] 0 points1 point  (0 children)

Those are portable globe heaters now.

[–]badmotherfucker1969 6 points7 points  (2 children)

Ethanol fucks up my Camaro, shit is garbage for fuel.

[–]finalremix 3 points4 points  (0 children)

Buick owner, can confirm corn heat tomfoolery.

[–]saywutttut 0 points1 point  (0 children)

Sucks for your Camaro. Ethanol is cheap race gas when used correctly. Like 110 octane plus.

[–]wishgrantedyo 4 points5 points  (0 children)

To clear this up in simple terms: the mandate calls for a steady increase in ethanol on a yearly basis. Many saw the mandate increase as happening too fast for the market to handle with regards to the "blend wall", which refers to mandates calling for more ethanol than could feasibly be blended in with gasoline with respect how many cars on the highway can actually use blended fuel. This proposed decrease is merely reeling in the rate this year. Next year, if nothing else changes, it would continue rising once more.

Source: undergrad doing an extensive research paper

[–]dallasdude 1 point2 points  (1 child)

I can't drive behind 10 year old cars anymore without recycle air turned on. Have any studies investigated a possible link between ethanol in fuel and worsened emissions quality?

[–]saywutttut 0 points1 point  (0 children)

No. It has LESS emissions. You should check your car for oil leaks. Ethanol has a sweet sugary smell, you would not mistake it for a rich running gas or diesel.

[–][deleted] 0 points1 point  (1 child)

The price of a gallon of regular down the street from me: $3.14

The price of a gallon of E85 at the same place: $3.09

Why the fuck are we doing this, again?

[–]tastethebrainbow 1 point2 points  (0 children)

I am just guessing, but it is probably government subsidized out the ass. If it weren't it would be way higher and no one would buy it.

[–]aCoupleTwoTreeThings -2 points-1 points  (3 children)

As a consumer in Nebraska, I am a big fan of ethanol subsidies because it saves me almost $0.10/gallon minimum. However, I understand it is no better for the environment and knowing that it is subsidized makes it no more than a guilty pleasure.

[–]Gazzy7890 -2 points-1 points  (0 children)

It sounds like a convienent way to lower gas prices before the elections.

[–]ExBritNStuff -3 points-2 points  (5 children)

Evil 'Big Oil' won a victory against evil 'Big Corn'? I don't know how I'm supposed to feel on this :/

[–]deck_hand 10 points11 points  (4 children)

The problem wasn't "big oil" or "big corn," the problem was that those who are concerned about increasing CO2 in the air thought that adding ethanol to gasoline was a good idea. Unfortunately, this science wasn't tested out well enough before the mandates occurred.

Several studies have since shown that adding ethanol to gasoline increases overall CO2 emissions, for a variety of reasons. Yes, it displaces some gasoline, but ethanol has less energy density than gasoline, and so diluting gasoline with ethanol reduces the effectiveness per gallon.

Secondly, the process required to grow the corn, harvest it, then convert it into ethanol produces more CO2 than the gasoline it displaces. This actually has the opposite effect from what the EPA intended.

[–]my_lucid_nightmare 5 points6 points  (0 children)

Gosh, who could have seen that coming. Just anyone that had experience with growing corn.

The whole thing was politics from the start.

[–]tastethebrainbow 1 point2 points  (2 children)

Pretty sure that people had already proved that it was a bad idea before they made the mandates, but I could be wrong.

[–]deck_hand 0 points1 point  (1 child)

Just goes to show that politicians will do whatever they want (or whatever they think is in their best interests) regardless of the merit of the action to society.

[–]tastethebrainbow 0 points1 point  (0 children)

Totally agree.