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Power Science

Switchgrass Makes Better Ethanol Than Corn 560

Posted by ScuttleMonkey
from the seemingly-easy-choice dept.
statemachine writes to mention that the USDA and farmers took part in a 5-year study of switchgrass, a grass native to North America. The study found that switchgrass ethanol can deliver around 540 percent of the energy used to produce it, as opposed to corn ethanol which can only yield around 24 percent. "But even a native prairie grass needs a helping hand from scientists and farmers to deliver the yields necessary to help ethanol become a viable alternative to petroleum-derived gasoline, Vogel argues. 'To really maximize their yield potential, you need to provide nitrogen fertilization,' he says, as well as improved breeding techniques and genetic strains. 'Low input systems are just not going to be able to get the energy per acre needed to provide feed, fuel and fiber.'"
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Switchgrass Makes Better Ethanol Than Corn

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  • by compumike (454538) on Friday January 11, 2008 @06:36PM (#22006648) Homepage
    It's true that corn is a pretty poor feedstock for ethanol generation. But I think most people (farmer subsidy lovers) think that ethanol has come into focus because of its potential as a fuel *replacement* for gasoline.

    Let me remind you why we have a demand for ethanol in the first place: a replacement for MTBE [wikipedia.org], a gasoline anti-knock additive (letting the engine run at higher compression ratios, and thus more efficiently) which was found to be leeching into groundwater and concentrating. MTBE is being phased out, and ethanol is a replacement chemical. Whether or not ethanol will be used as an energy source is irrelevant. It's critical today as a fuel additive for gasoline. Beyond that, it's a pretty inefficient energy carrier. Switchgrass may do better, but we're not there yet.

    --
    Electronics kits for the digital generation! Free videos -- click here. [nerdkits.com]
  • by Surt (22457) on Friday January 11, 2008 @06:38PM (#22006666) Homepage Journal
    When you replace oil with ethanol, you stop using carbon that was fixed a long time in the past (and thus did not contribute to present levels of co2), and instead use carbon that was fixed in the last growing cycle. The net co2 added to the atmosphere in a year is zero, because the corn/switchgrass has to fix the co2 before you can later release it in the burn cycle.
  • by sl0ppy (454532) on Friday January 11, 2008 @06:40PM (#22006726)
    except that many hops farmers have switched from farming hops on their premium farm land, to farming inefficient corn, thus driving up the price of beer.

    it's hard for something to be "free, as in beer" when a bottle of beer is very expensive to make due to a hops shortage.

    it never makes sense to burn our food.

  • by Your Pal Dave (33229) on Friday January 11, 2008 @06:48PM (#22006884)
    There is leftover grain after fermentation. It's called Distiller's Grain and it makes a good livestock feed (due to the vitamins in the yeast, perhaps?). Unfortunately, due to its moisture content, it cannot be stored for very long or transported very far, so a lot of it goes to waste.
  • by iamlucky13 (795185) on Friday January 11, 2008 @06:49PM (#22006892)
    This has been circulating around the intarwebs for a few days now, so it spurred me to do some background reading already.

    Corn has higher amounts of the simpler sugars that bacteria need to work on to produce the ethanol. Switchgrass and other cellulosic feedstocks, which are largely equivalent in feasbility in general terms, have those sugars bound up in...you guessed it...cellulose. Because of this it requires much more processing prior to fermentation. There are several ways to do this with varying costs and efficiencies, but at the very least is technically viable.

    However, this pre-processing and the fact that large-scale cellulosic ethanol production is a new technology means the initial costs are higher. According to Wikipedia (with original sources referenced), corn ethanol plants cost about $1-3 per gallon of annual capacity to construct. The first round of large scale cellulosic ethanol plants now under construction are billed about $7 per gallon of annual capacity. Production costs are expected to run about $2.25 per gallon initially, or about $125 per barrel of oil energy equivalent.

    However, as the method is proven, that cost is expected to come down. About $350 million of cost is also being funded by the federal government under the new energy plan. Also, the cost of the feedstock for cellulosic ethanol production is much lower, as it can use switchgrass as mentioned in the summary, corn stover, wood chips, or just about anything else containing plant matter, where as the corn method requires corn (duh), and thus competes with food production.

    Of course, the article makes the energy-return benefit over corn ethanol obvious. Elsewhere it has been estimated that cellulosic ethanol production could account for 30% of our transportation energy needs in a couple decades. Obviously far short of weaning us off foreign oil, but a start nonetheless. However, an added benefit of using grasses like switchgrass is the fields don't have to be replanted every year, reducing soil depletion and erosion.
  • by ranton (36917) on Friday January 11, 2008 @06:52PM (#22006934)
    because corn farming has a powerful lobby

    That is so funny that I almost fell out of my seat. Corn prices have stayed fairly constant for the past three decades. I am not talking about being adjusted for inflation. If the corn farmers have a powerful lobby then that must mean that lobbiest truly have no power at all. (not the case)

    If you take the price that corn sold for in the 1970s and adjusted for inflation, corn should be selling for above $10/bushel today. The prices of corn and other commodities have been kept low for years because there are more voters who eat food than there are who grow food.

    Sure corn farmers have lobbiests, but I cannot even fathom the idea that they are powerful. The only reason corn is being used now is because it is plentiful and doesnt take any major changes to the current agricultural industry to start using for ethanol. Politicians love making changes that sound good but dont actually take any work.

    --
  • by cromar (1103585) on Friday January 11, 2008 @06:55PM (#22006992)
    Hemp seed is actually really healthy [nutiva.com] and contains good amounts of all essential amino acids (and so is high in protein). It provides some iron, good amounts of manganese and magnesium, and is also a good source of omega-3 and -6 fatty acids. Hemp seeds are good for salad toppings, baking, etc (think multi-grain bread). Hemp oil is also highly nutritious and can be used as other vegetable oils are.

    It's a shame that prohibition drives the seed prices through the roof.
  • by Anonymous Coward on Friday January 11, 2008 @06:56PM (#22006998)
    Biofuels from plants (any plants) recycle carbon dioxide from the atmosphere. Fossil fuels all release more carbon that's been sequestered in the ground for millions of years and add to the CO2 burden.
  • by nine-times (778537) <nine.times@gmail.com> on Friday January 11, 2008 @07:11PM (#22007238) Homepage
    I don't know about hemp, but according to the summary:

    The study found that switchgrass ethanol can deliver around 540 percent of the energy used to produce it, as opposed to corn ethanol which can only yield around 24 percent.

    This means that corn gets you negative amounts of fuel (you'll use more farming it than you'll get out of farming it), while switchgrass gets you fuel.

    The only reason corn has been chosen as the main crop for getting ethanol in the US is because of the strong cron lobby. It really isn't a feasible energy *source*, since it uses more energy than it produces.

  • Sure corn farmers have lobbiests, but I cannot even fathom the idea that they are powerful.

    I get a check every year that disagrees with you.

    They may not be sugar-lobby powerful, but they still manage to farm the government well enough.

  • by Paradise Pete (33184) on Friday January 11, 2008 @07:17PM (#22007326) Journal
    That is so funny that I almost fell out of my seat. Corn prices have stayed fairly constant for the past three decades.

    You must have a rather slippery seat.

    The 2002 Farm Bill guarantees corn farmers a price of $2.60 per bushel in 2002-2003 and $2.63 per bushel in 2004-2007 for the corn that they produce. In order to realize this price, corn farmers are eligible to receive a combination of direct payments, loans, and counter-cyclical payments.

    Fixed Direct Payments: Set at a fixed rate of $.28 per bushel for crop years 2002-2007. These payments are based on historic crop yields, so farmers are not obligated to grow any crop in order to receive benefits. Since these payments increase in direct proportion to the acreage and yield of eligible crops planted, they encourage larger tracts of land to be used for corn cultivation.

    Loans: The marketing assistance loan program and the loan deficiency payment program work to bring the price of corn up above $1.98 per bushel in 2002-2003, and $1.95 per bushel in 2004- 2007. These non-recourse loans allow the producer to choose when and how much of the loan they are going to pay back. They skew market signals by acting as a price floor for current production and encourage overproduction. Counter-Cyclical Payments: If the price of corn is still below the $2.63 target, counter-cyclical payments are used. They work in the same way as direct payments, and are based upon historical crop acreage and yield instead of current production. Again, this means that producers do not have to produce in order to receive payments.

    Conclusion:
    Corn production is the most heavily subsidized commodity in the United States today. Payments are extremely concentrated and benefits flow overwhelmingly to corporate agribusiness. Current government policy is pumping up the bottom line of modern, profitable corporations and leaving the taxpayer to foot the bill.

    pdf [taxpayer.net]

  • by Radtastic (671622) on Friday January 11, 2008 @07:18PM (#22007360)
    IANA Biochemist, but it seems to me like switchgrass should take a back seat to Jatropha [wikipedia.org]? Jatropha would seem to ge the nod because not only does it grow in poor soil conditions, it already has a high oil content. Nor do we have to worry about any GE going on, as it isn't an edible crop. (Although its toxicity may pose other problems.)
  • by statemachine (840641) on Friday January 11, 2008 @07:23PM (#22007420)
    For all the people who are complaining about the summary/headline, please know that it is hard to fit all of the math in the headline. Please read the article for that. ScuttleMonkey redid my headline (although slightly more correct, he made it more vague).

    For those who say there aren't refineries, ScuttleMonkey took out my quotes and put different ones in. I said the DoE is partially funding new refineries, the first of which will come online in Georgia -- also in the fine article.

    Although I credit and thank ScuttleMonkey for greenlighting my submission whereas it was flatly ignored yesterday when I submitted it, please complain about his editing, and not my original content, if you feel the summary was vague or had omissions. You can compare both if you read the firehose submission (complain to me if you don't like that one).
  • by MyNymWasTaken (879908) on Friday January 11, 2008 @07:41PM (#22007628)
    Interesting. I hadn't heard of this before.

    It seems that BP is thinking along the same lines too.
    BP's Bet on Butanol [technologyreview.com]
    BioButanol: a better biofuel (fact sheet) [bp.com]
  • by davidsyes (765062) on Friday January 11, 2008 @07:48PM (#22007704) Homepage Journal
    Maybe this is restating what you've said, but the nice thing about switchgrass instead of corn is that the switchgrass frees up or releases from captivity the fields earmarked for use as corn-for -fuel use. This means that the recent uptick in crops-to-store-to-consumer pricing/cost should settle down. There was a big fear (in some quarters) that the cost of some foods related to/around corn/corn oils/etc would skyrocket.

    But, an aside: I think all I need to do is listen to NPR/TOTN/Science Friday, SciAm, et al, and pick up things half a week to a week earlier than get posted here. (And, like going to switchgrass from corn, I can deal with less dupes...)

    See:

    http://www.npr.org/templates/story/story.php?storyId=17910749 [npr.org]
    7 January 2008

    and:

    http://www.npr.org/templates/story/story.php?storyId=5183608 [npr.org]
    1 February *2006*

  • by gawbl (941021) on Friday January 11, 2008 @07:55PM (#22007786)

    Let me remind you why we have a demand for ethanol in the first place: a replacement for MTBE, a gasoline anti-knock additive (letting the engine run at higher compression ratios, and thus more efficiently)

    Not quite. On the basis of studies done in the 1970s, the US EPA decided that certain high-smog areas (e.g. Los Angeles) must use gasoline blended with an oxygenate. IOW, if you blend oxygen into the gas, the engine burns leaner, at least if you are using a carburetor.

    But nobody in the US uses carburetors anymore. Every modern car has fuel injection with an oxygen sensor; the sensor notices the leanness created by the oxygenate, and enriches the mixture. Bottom line: slightly reduced gas mileage, CA drivers pay more for oxygenated gasoline, MTBE or Big Corn make profits. There is no smog benefit.

    CA pleaded with the US EPA for years for an exemption to the oxygenate mandate; EPA presumably ignored CA due to pressure from MTBE and ethanol producers.

    which was found to be leeching into groundwater and concentrating. MTBE is being phased out, and ethanol is a replacement chemical.

    Mostly correct. MTBE is difficult to separate from water, and probably carcinogenic (unproven; nobody did the study). Besides, MTBE at 5-15ppb makes water taste like paint thinner.

    Example MTBE Contamination: http://www.epa.gov/region09/mtbe/charnock/index.html [epa.gov]

    Ethanol is no longer touted as oxygenate; instead, Big Corn touts it for carbon neutrality. Whether ethanol is really carbon-neutral depends upon who you believe. I'm personally very doubtful that corn-based ethanol is beneficial to carbon emissions; dunno about sawgrass.

  • by zogger (617870) on Friday January 11, 2008 @08:05PM (#22007916) Homepage Journal
    Jatropha will not grow in the bulk of the US landmass, it is a subtropical plant and can only tolerate a few light frosts. I looked into it for a fuel crop here and even this being Georgia, we are too far north.

    I agree with the other poster, either switchgrass or industrial hemp are better targets for exploitation for biofuels using marginal land in most areas of the US.
  • by ArcherB (796902) * on Friday January 11, 2008 @08:07PM (#22007942) Journal

    Hemp seed has almost no appreciable THC content and is more nutrient dense than soybeans.
    True, but the redeeming factor of soy is that it provides complete protein.
  • by That's Unpossible! (722232) on Friday January 11, 2008 @08:15PM (#22008064)
    1. Growing corn gets you food OR fuel, not both.
    2. Corn is subsidized, thus its true costs are hidden from us.
    3. Corn must be re-planted every year from seeds. Switchgrass is a perennial whose 'produce' can be harvested from the same plant each year.
  • summary error (Score:2, Informative)

    by penguinbroker (1000903) on Friday January 11, 2008 @08:29PM (#22008282)
    ftfa - "This means that switchgrass ethanol delivers 540 percent of the energy used to produce it, compared with just roughly 25 percent more energy returned by corn-based ethanol according to the most optimistic studies."

    corn-based ethanol therefore delivers roughly 125% of the energy used to produce it, not 24%
  • by merreborn (853723) on Friday January 11, 2008 @08:35PM (#22008366) Journal

    Growing corn gets you fuel, OR food. Farms aren't going to use the same crop to produce fuel and food-- they'll produce one or the other.

    Also, should your fuel sources be competing with your food sources?


    To reinforce your point, animal feed prices have tripled due to increased demand for ethanol, which in turn has driven up the price of beef.
  • Re:Follow the carbon (Score:5, Informative)

    by jeff4747 (256583) on Friday January 11, 2008 @08:49PM (#22008574)

    ...which is then put right back into the air when burned in cars.

    Hence the term "Carbon Neutral".

    After the fuel is burnt, you end up with the same amount of CO2 in the atmosphere. OTOH, with petrofuels, you end up with more CO2 than you started with.

    Most of that electricity is from coal-powered plants

    At the moment, yes. But there's little reason to believe that will always be the case, especially with the advances in wind, solar and tidal power, coupled with increased intrest in Nuclear power.

    the heat comes from burning excess material, which continue to put carbon back in the air and pull carbon from the ground

    The excess material was created by removing CO2 from the atmosphere. So burning it is still carbon-neutral.

    Click the Energy Balance tab to see input vs. output of carbon.

    I'm not sure what the heck you're talking about here. The Energy Balance tab has nothing to do with carbon. It's comparing the energy of the final fuel to the energy required to make it. Energy is energy in that graphic, whether the energy comes from oil or from a nuclear reactor.

    Now, if you're talking about the CO2 tab, that one actually does deal with carbon. However, there's several sources of ethanol, so it's not clear what you're referring to. The worst being corn at 22% reduction, and best being celluose at 91%
  • by cromar (1103585) on Friday January 11, 2008 @08:51PM (#22008608)
    LOL. Good one. I was just thinking I should have mentioned it doesn't have any THC in it!
  • by spineboy (22918) on Friday January 11, 2008 @09:06PM (#22008776) Journal
    Sugar beets have a high sugar content(therefore can make more EtOH), and can grow in fairly cold, adverse environments. Grows quite well in North America. Corn is being used because of the lobbying effort of Archer-Daniel Midland, a world leader in processing corn, wheat, soybeans. Corn is a lousy product to make ethanol.

    Ethanol yield/per acre for sugar beets is about 2x times that of corn, and about 25% higher than sugar cane.
    Sugar cane is more efficiently made into ethanol yielding 8 times as much energy as required to make it, sugar beets only about twice. Corn is nearly an even output.
  • by pclminion (145572) on Friday January 11, 2008 @09:13PM (#22008846)

    except that many hops farmers have switched from farming hops on their premium farm land, to farming inefficient corn, thus driving up the price of beer.

    Mass produced domestic beer IS going up in price, but this is not really because of the hop shortage. The hop shortage is severely affecting the homebrew and microbrew markets, but the big brewers don't use much hops, if any, in their brews. Instead they use isomerized alpha acid, a synthetic version of one of the major hop bittering compounds. Sam Adams is the only mass brewer I know of who actually uses real hops exclusively.

    Beer prices are spiking mostly due to rising grain prices. However, the hop situation does suck. I've seen hops triple in price in the last year. And since I typically brew IPAs, I use a lot of hops and this hurts bad. I have my own plants but the output is nowhere near what I need for a year's worth of brewing. It is sad to see the fields getting ripped up and replanted with corn, which after all is only profitable because of government subsidy.

  • algae (Score:3, Informative)

    by zogger (617870) on Friday January 11, 2008 @09:50PM (#22009216) Homepage Journal
    I would be in favor of more algae research and deployment, but not necessarily in the oceans but in controlled pools/tanks in the desert, in combination with some some solar and geo thermal and perhaps very large greenhouses. And mostly because they will most likely go for genetically modified algae and I wouldn't want to chance such a crop going wild with unintended consequences. I also think they could control it better in pools or tanks than in the wide open ocean. I've worked on the ocean before, it ain't always a flat millpond...

    I think the energy question will be answered with an "all of the above" solution, I am not seeing any single one solution fitting all circumstances everywhere. although back to the jatropha, mexico's oil fields are now in decline, it probably wouldn't hurt them a bit to see if they could start to squeeze a few million acres of the plant in there before it goes into fast decline....

    Personally I am trying to eventually go full personal production for the fuels I need/use, to decentralize production (doing my bit to be part of the solution rather than just part of the problem), and also pure self interest-keep my wallet stuffed more than "theirs". I am not real far along yet, just wood as primary heating fuel, perpetual supply and carbon neutral, some solar PV,a greenhouse for year round food production (helps drop shipping demand/fuel use/pollution from imported foods, plus it is just better to make your own food onsite, IMO, tastier!), but am working towards liquid biodiesel next, that's why I happened to know about the jatropha, I had looked into it and had to abandon the idea. Most likely we will be looking at using waste chicken litter for a feedstock source, as we have that in rather large abundance ;)

  • by Anonymous Coward on Friday January 11, 2008 @09:55PM (#22009240)
    There is a bit more then that stopping the widespread deployment of butanol. Butanol is primarily made from natural gas (IE- an oil product). The bio-converters and bacteria used to make butanol are more sensitive, and much more difficult to convert into an industrial scale bio-converter.

    Butanol also gels at a much higher temperature then gasoline or ethanol; which makes its use as a winter fuel (You either have to have a pressurized pump that can push gelled fuel until the engine warms up enough to liquefy it; or adding some other additive to lower it's gelling point).

    That said; butanol is .80/l right now so anyone who doesn't mind keeping barrels of it at there home and the high gelling point is not an issue could convert today.
  • by Lost Engineer (459920) on Friday January 11, 2008 @10:14PM (#22009414)
    What in the world makes you think nobody would produce corn here if it weren't subsidised? There's simply no better place to grow it than the midwest. Without subsidies it would simply be more expensive in a direct fashion, rather than through taxation.
  • by reverseengineer (580922) on Friday January 11, 2008 @10:31PM (#22009568)
    The sugar price supports paradoxically play a big role in hurting Hawaii's sugar industry. The price floor means that the minimum price for sugar from Florida, Louisiana, and Texas is the same as that for Hawaii, so producers in those states make just as much money for their sugar, but have much lower costs for labor and transportation. The supports are also a significant incentive to producers in those other states to produce as much as they can, which negates Hawaii's dramatic per-acre productivity advantage.
  • Energy != oil (Score:3, Informative)

    by Dire Bonobo (812883) on Friday January 11, 2008 @11:20PM (#22010066)

    I've only looked at corn ethanol in much detail, but that stuff requires MORE oil to produce, per unit of burnable energy (that you can actually pump into your car), than gasoline does. It gets fertilized with oil, harvested with tractors that run on oil, transported with oil ... by the time it gets to your tank, it would have been better just to use the stupid oil to begin with.

    That's total nonsense. Not all energy is oil!

    Take a look at the studies on ethanol - Pimental's, for example. About 90% of the energy involved is for (a) fertilizer, or (b) distillation-process heat, neither of which involve oil!

    Basically, you've been fed a lie.

    Maybe switchgrass is a little better than corn

    It's better by about a factor of four; that's more than "a little".

    Brazillian sugarcane ethanol is similar to switchgrass in that regard. Basically, anyone who's only looked at corn ethanol has a very, very biased view of what can be done. US-grown corn ethanol is a ridiculous product - it's agricultural subsidies in a bottle - and shouldn't be used as the basis of any sensible technological comparison.

    Show me a large-scale ethanol process, sunlight-to-tank, that doesn't take petroleum as an input

    Don't be absurd. Oil isn't going to vanish overnight, and agriculture uses such a small fraction of it (~5%) that even peak-is-nigh models like ASPO's predict the world will have plenty for agriculture for decades to come.

    Moreover, demanding that alternative energy sources make no use of current energy sources is as useful as demanding they turn the moon to green cheese - there is absolutely no economic benefit to cutting an alt-energy business off from the world's infrastructure, so nobody who's running such a business will do it. Insisting they should is no more than a way to ignore their results as "not counting".

  • by Anonymous Coward on Friday January 11, 2008 @11:28PM (#22010142)
    >Growing corn gets you fuel, OR food. Farms aren't going to use the
    >same crop to produce fuel and food-- they'll produce one or the other.

    I am a farmer, and I'm right in the middle of this. I'm hoping to profit nicely from ethanol demand.

    The corn I grow is a commodity. I really don't care if the buyer uses it for food or ethanol production. I store it in my grain bins and sell it when the price is right.

    Corn is a nicely flexible commodity. I like it.

    >Also, should your fuel sources be competing
    >with your food sources?

    It doesn't really matter. We farmers can grow extreme amounts of corn without much effort. We're so good at it, we've had to hold ourselves back on production for decades.

    Switchgrass, on the other hand, doesn't have much use other than (potentially) as fuel. I sure don't want to eat it. I could grow it quite easily if the market demands it, but I'd need to tool up with different equipment and farming techniques. It's a real hassle to bale and store hay...I don't expect switchgrass would be much different. The root system created by switchgrass would make a field hell to get back to where I could plant corn again if it were needed for food.

    I can't think of any marginal land where growing switchgrass would make much sense, either. If it's not growing corn, I've got better uses for it, even if it is only grazing land for livestock.

    >Growing hemp gets you fuel, food, and fiber.

    Don't get me started on that damn ditchweed. It's rough on equipment. My family tried it years ago when it was needed during the wars. We're still trying to reclaim land lost to it. You can't eat it, and you sure as hell can't smoke it. About the only decent thing I can say about it is it's good for erosion control. That's why it's called ditchweed.

    >Hemp doesn't produce a sizable amount of food.

    Damn straight.
  • by uvajed_ekil (914487) on Friday January 11, 2008 @11:43PM (#22010280)
    Hemp oil is also highly nutritious and can be used as other vegetable oils are. ...and for some odd reason, an hour after dinner you get this uncontrollable urge to eat a LOT of Twinkies. (I know, I know... but I couldn't pass up the chance to say that).

    Yeah, good one, that's hilarious. Perpetuating utterly false misinformation that keeps a highly useful and sustainable crop from being legal is SO funny. If that is clever, I've got another one for you:

    Hemp seed is imported into the US only by terrorists, it shreds puppies, and hates Jesus. It is also highly radioactive, makes people sterile, and originated on planet Xircon 6. Hah! So funny. OMG lol.

  • by MrHops (712514) on Saturday January 12, 2008 @02:11AM (#22011434)
    Keep in mind that ethanol doesn't require the nitrogenous components, so most of the "waste" can be put back on the fields.

    Yes, there will be loss, but it's not anywhere near as bad as some make out. Any decent organic farmer can lecture for hours on the wonders of compost, and as long as the farmers are careful about irrigation runoff, it isn't too bad.

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