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Ethanol to Hydrogen Reactor Developed
guacamolefoo writes "CNN reports that researchers at the University of Minnesota have developed a small (2 ft. high) hydrogen reactor that turns ethanol into hydrogen and then uses a fuel cell to turn the hydrogen into electricity. It notably does not use fossil fuels in the process. I knew that liquor would save us all some day."
One item of interest is that this new technique converts ethanol to hydrogen at a 60% efficiency rate, compared to the 20% efficiency rate with current technology.
to create a 1-1.5 gallons of ethanol. Cover article of Harpers last month...
That article is pretty damn skimpy on the details. Check out this one which I found at ArsTechnica. Perhaps the most important detail is that a rhodium-based catalyst needs to be heated to 700 celsius for the reaction to have any efficiency.
---- El diablo esta en mis pantalones! Mire, mire!
The IOP web site here claims that ethanol to electricity is 3x more efficient than ethanol for powering vehicle engines.
Well, no doubt fossil fuels are used somewhere along the lines, but this makes it sound pretty simple and mostly biological.
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As taken from here.
Ethanol is an alcohol-based alternative fuel produced by fermenting and distilling starch crops that have been converted into simple sugars. Feedstocks for this fuel include corn, barley, and wheat. Ethanol can also be produced from "cellulosic biomass" such as trees and grasses and is called bioethanol.
Yes it takes a lot of energy to make - a lot of solar energy and water in a method commonly known as 'growing'.
There's a growing sense that even if The Future comes,
most of us won't be able to afford it.
-- Lemmy
Ever noticed how most foods and drinks are sweetened with "high fructose corn syrup", rather than the simpler "sugar", and thought it was a bit odd? I'd always just assumed that it was to disguise the ingredient, but that seemed pointless given the nutritional listing of sugar content. Apparently the resolution is that the US government mandates a price for sugar which is about twice the global one. It does not mandate such a price for corn syrup, so corn syrup is cheaper. The major manufacturer of corn syrup (Archer Daniels Midland) "donates" generously to both parties to ensure the continuation of this policy.
(ADM also runs a mammoth ethanol boondoggle based on government subsidies. Every dollar of profits earned by their corn sweetener operation costs consumers ~10$, every dollar earned by their ethanol operation costs taxpayers ~$30.) (ADM also runs a mammoth ethanol boondoggle based on government subsidies. Every dollar of profits earned by their corn sweetener operation costs consumers ~10$, every dollar earned by their ethanol operation costs taxpayers ~$30.)
Ethanol takes energy to make. Lots of energy, possibly more than it contains. That energy comes from fossil fuels.
Today that may be the case. It may not always be that way. I think that if we used more nuclear power, ethanol would make even more sense.
I am not opposed to "alternate energy" sources. I think that ethanol, wind, geothermal, fusion, and solar power should all be researched. We have to use what works for now, and that is fossil fuels, but we won't have fossil fuels forever. We need to look towards the future. We need to be prepared to use other sources of energy.
Even if we didn't use ethanol as a primary fuel source, it can have other benefits. Mixing ethanol with gasoline reduces emissions.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
I call bullshit.
It's true that energy is required to make ethanol, but the most of that energy is bioenergy from the yeast, converting the starch to ethanol + C02. The starch must be heated before it can be converted (gelatinized), and there is some energy required for that but typically done simply from the heat of crushing the corn.
The bulk would be the distilling process, but you could EASILY create a solar distillery or gelatinizing process, too, which is where the bulk of any added energy comes from.
Point is, you can be as inefficient as you like and claim that it's some corn cartel. But I'm not pulling out my tinfoil hat just yet.
As an aside, it's fairly trivial to get a BATF license to distill for fuel.
>ethanol from fermented corn is not gonna work, >primarily since all of the farm machines need >gasoline
Uh. Diesel. Almost all farm equipment have run on diesel for the last 40 years. And bio-diesel is a reality....
But there are two considerations to make here that are not part of the above statement:
Yes. Ethanol engines require very pure ethanol. Ethanol is produced by fermenting biomass (in this case, corn). The end result is a ethanol/water mixture, which requires extensive purification in order to be useful. This reactor tolerates ethanol/water mix around 50% (they used 103 proof ethanol). You eliminate the distillation costs which makes this reactors a lot cheaper than a pure ethanol engine.
(Actual article for this instututions with subscriptions is here. The Science summary is here.)
The only problem with theory is that most corn isn't grown where that High Plains Aquifer is. (Sure, there's a bit here and there, but most of that part of the country is wheat and grazing land.) Corn does take a lot of water, so it's mostly grown where the water is: Ohio, Indiana, Illinois, Iowa, etc. The draining of the High Plains Aquifer may be a problem, but it doesn't affect corn production.
From the article: "The cell could produce 1 kilowatt of power, nearly enough for an average home."
) turns up numbers showing that an iron takes about 1.2KW, or just over 1KW for a toaster. So almost enough for an average home, so long as I wander round the house turning off everything else before flattening my shirt or browning some wheat. That's handy.
A bit of googling (http://www.arctic-cat.com/generators/wattage.asp
(This occured to me because I have a fusebox that can't cope with me using a medium iron and an electric heater on low in the same room. Domestic bliss.)
The reactor pushes a mixture of watery ethanol and air over a rhodium-based catalyst heated to about 700 ?C. It takes only five seconds to start up, and produces a steady stream of hydrogen and carbon dioxide with very few other waste products.
Ethanol causes Pollution too
Ethanol wrong for CA
I've seen other materials cited saying that ethanol is not harmful. Regardless, I'm sure that the pollution that is generated by your corn-fed in-house ethanol-hydrogen fuel cell will be contained by the time this thing gets to market.
While it may not use fossil fuels, I've been told a few times the largest viable source of ethanol is industrially cracked ethene (I think) from crude oil.
I guess once we got the vehicles etc. converted to this fuel we could set up fermentation plants if the oil ran out, but it still looks to me like the oil companies are safe for now.
Ethanol has been used as a fuel for a long time in many countries, often substituted on a percentage basis with regular gas. It was especially useful during wars etc when petroleum were in short supply.
Engineering is the art of compromise.
This assumes that we are using current techniques to farm the corn and ferment and distill it. If the farm machinery can use biodiesel instead of fossil diesel then that part is taken out. If the the still can be heated using solar heating (direct solar heating, not using inefficient solar cells), some use of wind, etc. then it may be possible to make the equation go positive for us.
As long as the input is fossil fuels or ethanol or hydrogen (perpetual motion machine, anyone?), efficiency means we'll come out behind. As plants learned long ago, you need outside input of power for it to be worthwhile which is why some researchers are looking at bacterial catylists among other things to split out the hydrogen from water. Plants left hydrogen behind a long time ago so perhaps we're going down a dead end.
$#!^ happens, but why does it always have to happen to me???
You can't drink it, of course.
To the nay sayers pointing out that it takes 1-1.5 gallons of fossil fuels to make one gallon of ethanol you missed a important part of this. "Ethanol can usually only be burnt if it is completely free of water - and getting the water out is an energy-intensive process. Schmidt's reactor works with wet ethanol." So this doesnt require PURE ethanol, it can accept the water being left in, which according to that statement is a large part of the energy intensive process to make ethanol. So this isn't the 'pure' ethanol.
This USDA paper addresses the issue. It compares various ethanol studies and concludes a positive energy balance in production.
But the real trick is reducing the costs of processing cellulose to ethanol to make it competitive with processing glucose from corn (which is more easily broken down) into ethanol. This is trivial when you eliminate all the subsidies, it's just a bit harder when you consider the heavy corn ethanol subsidies. However, companies like Iogen have been producing much more efficient techniques such as enzymatic hydrolysis for breaking down cellulose into an easily fermentable form - which they goes into the yeast fermentation process. The technology is already being deployed at modest scale factories.
So the answer is that yes, yeast do the fermentation. And to make fossil fuel-free, net energy positive ethanol, you just add some weak acid or strong enzymes to the mix earlier on to make sugars that are more easily fermented. As for carbon emissions (as CO2 or otherwise), which you mention, ethanol from cellulose "consumes" as much carbon in the growing plants as it releases when combusted, and in that sense it is both renewable and net-carbon-neutral to the environment. So does ethanol from corn, though the fact that the overall energy production is negative in that case means that the energy deficit has to be made up, generally by burning fossil fuels to generate energy for growing and havesting corn.
Which brings us back to many people complaining here on Slashdot that ethanol is bad for the environment. They just don't understand that ethanol != corn ethanol.
8.3 light minutes.
Why did GEAR crush RDP?
The paper addresses some of the issues raised in the column you linked. Pimentel in particular. It compares the results of several studies and attempts to address them.
Pimentel (who comes up with the negative energy results) tried to include some very hard to quantify items, such as the energy required to build the farm machinery that was used to grow the corn. Certainly a valid input, but he provides no details as to how he came up with his numbers.
Growing all that corn also takes a Lot of Water. more water than rain.
I grow corn in wisconsin and am very surprised to learn that it takes more water than rain. We, for reasons of topology, don't irrigate and our corn and still grow 125-150 bushel corn.
In short, the parent should be modded -1 overgeneralized.
Using power from our very own stellar fusion reactor located at a convenient approximate 18 light minutes, is much cleaner.
That's 8 light minutes, and there are no solar panels yet that are efficient enough to drive a car, much less a tractor. Have you taken a look at how many watts it takes just to get one horsepower? You'd need a small nuclear reactor to produce enough watts to get the 450 horsepower of a tractor! (A 335 Kilowatt reactor to be exact.) Not to mention the number of batteries it would take to keep a tractor running at night.
Solar power is a niche market. It has its uses, but general power generation is not one of them.
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If ethanol is actually to play an increasing role in the energy needs of the first world (or the US specifically), it will not come from corn, it will be a result of the refining of sugar cane in Latin & South America & the Caribbean. Sugar cane has a much higher energy level and is much easier to convert to ethanol.
Quick quiz: which nation is the largest producer of ethanol, and what is its feedstock?
And as long as we are injecting facts into this discussion (yes, I'm new here...), while corn production does require lots of water, less than a third of US corn production is irrigated.
And finally, as for all of the "Does producing ethanol require more energy than it uses" discussion, the real question is whether ethanol is an efficient mechanism to capture solar energy and store it in chemical form. The evidence is mixed. The professor at Cornell who is frequently cited is David Pimentel, an entymologist. According to those who specialize in energy, the conclusion for corn-based ethanol is much, much more nuanced. Newer processing plants (those built in the last 3 years) fed by farmers using appropriate nitrogen application techniques are energy-positive. But there are many legacy plants (as well as legacy farmers). Again, in the long-term, the cost of conversion & transport from warmer climes is actually more relevant, though.
And yes, by the way, IAAAE (I am an agricultural economist). In fact, IAAGE (I am a grains economist for a Big Ten University)
Answer: Brazil, sugar cane.
While production of ethanol can be inefficient rarely does it result in a net energy loss. Several different studies show anywhere from a 38% net gain in energy to over 100% depending on methods use. The generally cited claim of a net energy loss from producing ethanol all seem to come from only one paper written by David Pimental. To support his claims he seems to have taken a worst pratices view for every step in the production process, a realworld combination found in less than 5% of current ethanol production. The more comphrensive studies I've been able to find show a slight, albeit not stellar, net gain in energy. The most recent (2002) by Michigan State shows a net gain of 0.56 MJ/MJ of input for corn based ethanol production. If one looks at Cellulose based ethonal production, studies show almost a 2.5 net energy gain and it is easier on the environment since it requires less maintenance and fewer fertilizers.
o ne tenergybalance.htm
For reference this site has some good links, including a rebuttal of the Pimental paper (as well as showing the Pimental article).
http://www.econet.sk.ca/pages/issues/ethanolinf
As for needing a nuclear reactor to power a tractor, bullshit! See my post below where I point out that the big mining dump trucks as well as trains are all electric. They use the diesel motor to power a generator which in turn powers the electric motors. All you need to do is replace the diesel motor and generator with something like a big hydrogen powered fuel cell...
I was kidding about the nuclear power plant. Mostly because it was assumed that you aren't running it off of a chemical fuel like diesel. You said yourself that the electric mine cars are hooked to a diesel generator. But you're not going to get the necessary energy out of solar panels.
Corn is solar powered. Just because it is not efficent (yet) to convert light directly to electricity, don't forget how much energy falls on every acre of land from the sun. It's just the storage method you use that may be inefficient or polluting.
How much corn does it take to generate 335 kilo-joules of energy? How long does it take for that corn to grow? I'm willing to bet that miles of traditional solar panels will still produce more power over the same amount of time. But who wants to give up hundreds of thousands of acres of land for solar power generation?
If you look at oil, you'll find an even worse energy production rate. How many thousands of years does it take nature to produce a tank of gas?
Face it. Nuclear power is the only source of power that can produce enough power to maintain our civilization long term. Nuclear fuel is plentiful here on earth and in the rest of the solar system, it can be made cheaply, and it doesn't output tons of radioactive material per day. (*cough*coal plants*cough*) Instead of developing low power density fuel cells, we should be developing micro-power plants for use in industrial equipment, and small, safe, and efficient nuclear plants to replace our aging, dirty, and expensive power grid.
Sorry if I'm getting off topic here, but fuel cells are quickly becoming a pet peeve of mine.
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Ethanol is a lot easier to transport, refill,... than hydrogen. I bet a lot of energy is wasted in the ethanol->hydrogen reaction. So why not just use the ethanol directly?
More energy is used to purify the ethanol to standards that make it compliant with current internal combustion engines than is ever won back from burning the ethanol. I.e. the ethanol must be modified to emulate gasoline in order to be burned directly, and that takes a lot of energy.
Ethanol having its hydrogen extracted doesn't require any such purification process, making the conversion of ethanol->hydrogen, then burning the hydrogen, vastly more effecient than burning the ethanol directly. three times more effecient, according to the article. This leads to a situation where we can remove traditional energy sources from the equation, using the sun+soil+water to grow the crop, using sun+some small amount of energy to ferment, using some small amount of energy to extract the hydrogen, then burning the hydrogen. As long as the energy won from the sun is greater than the energy used to ferment the ethanol and to extract the hydrogen we have a self-sustaining energy economy (assuming we aren't draining acquafers and the like).
Best of all, we can produce the energy here at home, and stop pouring dollars into countries with regressive religions and toxic idealogies...which in turn might do something to slow the spread of toxic idealogies in our own countries.
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the catalyst is aluminum oxide covered in rhodium and cerium oxide.
the ethanol vapor only needs to be heated slightly. the catalyzation causes energy to be released (heating it to 700C). the waste heat can then be used to heat the ethanol vapor.
the rhodium is exteremely expensive as far as catalysts go.
Now, Lanny Schmidt of the University of Minnesota, Twin Cities, Xenophon Verykios of the University of Patras, Greece, and colleagues have developed a potentially portable ethanol converter. In it, a solution of ethanol and water passes through a fuel injector--a nozzle that ordinarily pumps gasoline into a car's motor--and into a gently heated chamber, where it vaporizes and mixes with air. The mixture then passes through a porous plug of aluminum oxide covered with rhodium and cerium oxide, which catalyzes reactions that yield hydrogen and carbon dioxide. The reactions heat the catalyst to over 700C, which keeps the process going. The gadget converts essentially all of the hydrogen in ethanol into hydrogen gas, the researchers report.
"Their process has the advantage that it is very, very fast," says James Dumesic, a chemical engineer at the University of Wisconsin, Madison, who is working on producing hydrogen from sugars. But he points out that the ethanol process also generates a lot of carbon monoxide, which the high-power fuel cells that might someday propel cars cannot tolerate. Gabor Somorjai, a chemist at the University of California, Berkeley, points out that rhodium happens to be "the most expensive catalyst you can ever make."
Earth is closest to the sun (perihelion) when the northern hemisphere is experiencing winter, and furthest (aphelion) when the northern hemisphere is experiencing summer. (In 2004, perihelion was on Jan 4, and aphelion will be July 5. [source])
Earth's perihelion: 147,000,000 km = 8.17 light-minutes
Earth's aphelion: 152,000,000 km = 8.44 light-minutes [source]
it takes more energy to produce the ethanol than you get back in stored chemical energy. I am sure that no one disputes that.
I dispute this. Having grown up on a grain farm I have a very good handle on the fuel and fertilizer inputs. Being a hobbiest beer and winemaker I have a very good handle on the mashing and fermentation processes. Being very good friends with a fellow who runs a commercial water distillation plant I have a very good handle on the state of high efficieny distillation systems.
This idea stems from work by David Plimentel at Cornel. (see my other post) David analysed horribly ineffecient coal fired distillation systems. His assumptions are incorrect.
One example is as follows. corn can easily produce over 100 bushles per acre. Barley can easily produce over 40 bushels per acre in the dry land farming areas I grew up in. Since barley weighs in at 48 lbs/bushel - that is nominally a tonne of grain per acre.
A 40 acre feild can be plowed in about 6 hours using a tractor and plow that runs about 3 1/2 MPH and burns about 3-4 gallons of fuel per hour. This means that plowing the feild can be done with under about 20 gallons of fuel - or about 1/2 barrel. A tractor of this size is about 70 horsepower and that compares favorably to your SUV which burns 3 gallons of fuel per hour while running down the highway at 60 MPH while it gets 20 MPG fuel economy.
It takes about 4 trips over the feild - one for 1st spring working, another for sowing the grain, another to take it off and another for working the field in the fall. Typically it will lay fallow for one year in 4 and during this year it will need to be worked 3-4 times. Since each trip requires in the ball park of a 1/2 barrel of fuel, the farmer will use about 1/2 x 4 x 1.5 = 3 barrels per crop for the 40 acre feild. To this we need to add fertilizers and these typically are applied when I was doing it at about 40 lbs/acre and each sack of fertilizer weighted 80 lbs so that 40 acre field needed 20 sacks of fertilizer or about 3/4 tonne. Present day fertilization levels are much higher mind you.
Nevertheless, chemically the fertilizer was something like 11-48-0 or 11-55-0 and this translates to 11% nitrogen by weight - typically in the form of ammonium phosphate. The chemical formula is NH4H2P2O5. If we look at jsut the nitrogen which is typically made by starting with Methane (CH4) and replacing the Carbon with a Nitrogen then we are looking at about 11% by weight Nitrogen (which is what the 1st number stands for) and that works out to adding about 11% of 3/4 of a tonne of Nitrogen to the feild. This works out to about 165 lbs of Nitrogen.
On a per pound basis the energy in Methane is not all that much different than liquid fuels... a few percent but within 15%. There is more energy in the carbon bonds than the hydrogen bonds so fuels like Diesel carry more BTU per pound than gasoline (predomenantly parafines: C(n)H(2n+2)) and similarly gasoline carries more BTU per pound than methane.
atomic weights: C=12, N=14, H=1 This implies that CH4=16 and NH4=18. They are within 12% of each other. Thus it is fair to say that 165 LBS of Nitrogen on the feild is about the same as 18/14x165=212lbs NH4.
Since the methane is lighter it is fair to say that we'll need in the ball park of 200 lbs CH4 as a chemical feedstock. At 8 lbs/gallon (Gasoline), 200 lbs represents about 25 gallons or just over 1/2 barrel of oil equivalent (BOE).
Well - we started with the farmer using 3 barrels of oil in the form of liquid fuel to plough the land. Next we calculated the energy input by way of Nitrogen in the form of NH4 and got about 1/2 barrel more - albeit at a low fertilization level so lets double it!!! Now our farmer is up to 4 barrels for his crop of 40 acres. That is 10 acres per barrel... but we do have other unaccounted for energy inputs like the coal used t
I assume you mean 125-150 bushels per acre?
;-)
Yes. In the vernacular "100 bushel corn" is 100 per acre.
Not being of an agricultural bent, I don't know if this is a realistic yield or not.
For my area it is a good yield. I suppose some people might go as low as 80-100, but they aren't making anything at that. Really pro farmers on really good soil might go 175 or even 200 if the weather works with them.
Is this measured on the cob or off?
Off.
For each bushel, how much waste (stalks & cobs, etc) is produced?
A ton. Perhaps literally.
Would burning 150 bushels' worth of (sun-dried) waste produce enough heat to distil 150 bushels' worth of mash?
Dunno. But it may not be the right question anyway. It may well be better to cut the corn like you would for silage and use the entire plant for mash, then use the increased energy production to heat to mix. I'm just speculating though, I haven't fact one to back up that guess.
How much gas does your tractor take to plant & harvest a 1 acre cornfield?
None. We use deisel.
In truth that answer depends on how many times you have to pass over the field. A no-till planter is going to cost you half a gallon an acre and combining is about a gallon and a half.
However, you will typically double or triple that without getting into nutty scenarios. If you are doing zone building that's going to be another gallon and a half, fertilizing can vary between a tenth and a half. If you chop for silage (as I suggest above) you burn three and a quarter per acre right there.
So, the amount varies widly depending on what you're doing.
The max theoretical energy conversion by plants using chlorophyll is only about 12%. [src: http://w3.aces.uiuc.edu/NRES/LPPBP/PathW.html]
This does NOT include the losses incurred by converting the resulting plant matter to booze!
So, yeah, solar panels are by far more efficient. But still suck. By "335kJ" I assume you mean '335 kJ/sec' or 335kW, and that would require 335m^2*(1/0.20) = 1,675 square meters of solar panel. The numbers are so big I am questioning the simple math.
The most disgusting thing is that I am going to disagree with you on the fuel cells from Ethanol sucking (well, you didn't say as much, but...): why? Because you don't use prime plant stock to create it. Ethanol can be made from much of the crap stock that is not worth the bother of bailing and / or packaging. Or the crap that goes bad. As long as there is some sugar left to distill (I mean, hell):...
And most importantly, nuke won't happen fast enough to clean our air before I die. Don't get me wrong, I love the idea of a bunch of smaller nuke plants. Not portable... I have my limits. But hell, the biggest sin in the transportation world is that nobody is building even CRUISE ships with nuclear engines. wtf?
Cheers