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Thursday, April 19, 2007 A New Biofuel: PropanePropane chemically derived from corn could be used in heating and transportation.
MIT researchers say they have developed an efficient chemical process for making propane from corn or sugarcane. They are incorporating a startup this week to commercialize the biopropane process, which they hope will find a place in the existing $21 billion U.S. market for the fuel. While much of the attention on biofuels has focused on ethanol, the process developed by the MIT researchers produces propane, says Andrew Peterson, one of the graduate students who demonstrated the reactions. Propane is used in the United States for residential heating and some industrial processes, and to a limited extent as a liquid transportation fuel. "We're making a demonstrated fuel" for which a market and an infrastructure already exist, says Peterson, who works in the lab of chemical-engineering professor Jefferson Tester and has founded the startup C3 BioEnergy, based in Cambridge, MA, to commercialize the technology. Propane, which is currently made from petroleum, has a higher energy density than ethanol, and although it is often used in its gaseous form, it's the cleanest-burning liquid fuel. The C3 BioEnergy process depends on supercritical water--water at a very high temperature and pressure--which facilitates the reactions that turn a biological compound into propane. Peterson wouldn't reveal the starting compound, but he says that it is a product of the fermentation of the sugars found in corn or sugarcane. The reaction is driven by heat, requiring no catalysts. At supercritical temperature and pressure, Peterson says, "water does bizarre things. It becomes like a nonpolar solvent" and mixes with the organic compounds. Once the reaction has taken place, the solution is kept under high pressure and cooled to room temperature so that the propane comes out of the solution and floats to the top. "We've demonstrated that we can make propane," says Peterson. "Now we're trying to optimize the reaction rate and get it to a scalable stage." Peterson says the biopropane conversion has a good energy balance: not much fossil fuel needs to be burned during production. The reaction does not require the input of a large amount of energy because the heat that's key to the biopropane conversion is recoverable using a heat exchanger, a device that transfers heat in and out of a fluid. "All biofuel reactions involve removing oxygen from the starting compound," says George Huber, assistant professor of chemical engineering at the University of Massachusetts, in Amherst. There are a number of strategies for doing this, including reactions that rely on biological catalysts. But, says Huber, "supercritical fluids are a very promising way to make biofuels. You can do it in a very small reactor in a very short time, so you can do it very economically." Other academic labs are developing processes that use high-temperature, high-pressure fluids to make biofuels. Douglas Elliott, at the Pacific Northwest National Laboratory, in Richland, WA, is using near-supercritical conditions in combination with a catalyst to treat wastewater and unprocessed biomass. Under these conditions, organic compounds can be made into a mixture of methane (the main component in natural gas) and carbon dioxide. "We've gone all the way from small-batch reactors to treating a few gallons of wastewater per hour," says Elliott, who is working with a company on commercializing the technology for water treatment. "We're still in the lab with biomass." Huber and Elliott say the MIT biopropane process is novel. "I've never seen anyone make propane with supercritical fluids," says Huber. In some countries, including Australia, propane is more widely used as a transportation fuel. In the United States, "you would have to modify engines to use it," says Huber. "Biopropane could be used where we already use propane." |
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Oil from Wood
11/09/2007
Comments
nekote on 04/19/2007 at 4:17 AM
109
Corn to Ethanol, as currently practiced, is finally beginning to be seen as the feel good, foolish, government subsidy, white elephant it is.
Great for corn farmers and ADM and farm Senators.
But,
Price of corn (and downstream food items) rising.
Price of gasoline with Ethanol also rising.
Mileage of gasahol being recognized as lower.
Pollution concerns about gasahol rising.
EROEI of corn Ethanol is somewhere between .8 and 1.2 (20% negative to 20% positive)
EROEI of corn to Propane?
At least >2 or 3?
Katherine Bourzac on 04/19/2007 at 9:38 AM
Associate Editor
7
edc on 04/19/2007 at 8:07 PM
1
What is the EROEI of regular gasoline?
I would also be interested in a non-partisan version of this number for ethanol.
nekote on 04/20/2007 at 4:48 AM
109
http://www.energybulletin.net/14745.html
(can't vouch for their "independence" / bias)
Initially, ~ 100:1
1970's ~25:1
current ~ 10:1
FWIW, other EROEI:
Biodiesel- 3:1
Coal- 1:1 to 10:1
Ethanol- 1.2:1
Natural Gas- 1:1 to 10:1
Hydropower- 10:1
Hydrogen- 0.5:1
Nuclear- 4:1
Oil- 1:1 to 100:1
Oil Sands- 2:1
Solar PV (2) - 1:1 to 10:1
Wind (2) - 3:1 to 20:1
killian on 11/26/2007 at 8:08 PM
54
chanokin on 04/23/2007 at 10:40 PM
2
McMillan968 on 04/19/2007 at 9:22 PM
38
Just what we need more uses for corn the RICH get richer!! Congratulations
Mr. Biofuel on 04/20/2007 at 3:34 AM
1
The problem with ethanol is that it makes a great additive to gasoline, but is not the optimal fuel for today's low compression, low octane engines. The widespread use of high concentrations of ethanol would optimally require a high compression, high octane engine which would then be unsuitable for the use of regular low octane gasoline when ethanol is not available. Using corn to make propane instead produces a fuel that already has a market and an infrastructure for sale and distribution.
Sounds like a good idea to me.
chuck@biofuelnetwork.net
http://www.biofuelnetwork.net
ryuuguu on 04/20/2007 at 2:49 AM
5
Bytesmiths on 04/25/2007 at 1:25 AM
3
I'm against making fuel from food. But biodiesel from waste vegetable oil could displace a tiny portion, perhaps 3%, of the total North American diesel fuel stream. Every bit counts, no?
My fear is that biodiesel will become a monster like ethanol has become, driving the price of soy way up. (Soy is a stupid feedstock for biodiesel, anyway, but them farmers only know how to grow beans and corn. :-)
secondmidnite on 04/20/2007 at 11:52 AM
2
wizardB on 04/23/2007 at 9:09 AM
13
Boilerman on 06/29/2007 at 2:48 PM
3
The subsides are received by the Oil Companies for blending their gas with Ethanol.
hawkeyestratigraphicinc on 04/23/2007 at 4:21 PM
1
Presently the US ethanol industry kicks out 0.31 Million Barrels a day or 0.114 Billion Barrels a year (note that the ethanol industry likes to quote their production numbers in gallons. There are 42 gallons in one barrel). In relationship to total US production ethanol represents 3.9% share of the US production, 1.4% of US daily consumption, or 0.004% of world daily consumption. Presently there is more ethanol infrastructure in place that there is corn available to purchase. As a consequence, corn prices have risen, and all the products that are derived from corn, including corn tortillas down in Mexico (up 40% in the last 2 years).
Ethanol does not have the same BTU that gasoline does.
Ethanol has 76,000 BTU/gallon. Gasoline has 125,000 BTU/gallon
Ethanol is 61% as effective as gasoline, so if you got 20 MPG on gas, you’d get 12.2 MPG on pure ethanol.
So the net effect of producing the annual US 114 Million Barrels Ethanol yields an equivalent 69 Million Barrels of Oil (gasoline) after BTU correction.
The total energy needed to produce ethanol from corn grain — including fermentation, fertilizing, fuel for farm tractors, harvesting and transporting the grain, building and operating an ethanol plant, and the natural gas used to distill corn sugars into alcohol — is about the same (within a factor of two plus or minus) as the energy content of the ethanol produced. Studies have concluded, though no peer-reviewed academic studies, that ethanol production yields more energy than it consumes, in a ratio of about 1.34:1, or that corn ethanol yields 26% more energy than is used to make it and that 74% of each gallon of ethanol produced is required to replace the energy used in production. In other words to produce the 114 Million Barrels of Ethanol every year, we use 84 Million Barrels to make it. So the net “new” energy produced is 30 Million Barrels Ethanol annually. After equating this for BTU content, it yields 18.3 Million Barrels of oil equivalent. At 18.3 Million Barrels a year, the US oil industry presently produces that equivalent amount in 2.4 days, the world oil industry produces that equivalent in 6.46 hours.
To put this new resource in a cost perspective, the US taxpayer subsidied the corn-ethanol cycle to the tune of $3,300,000,000.00 in 2004. Therefore the net cost of adding the 18,300,000 Bbls of “new” ethanol fuel comes at a net cost of $180.32 Barrel to the American public, or $4.29/gallon. This is one of the dumbest “feel good – green” deals I have seen.
The above facts do not even factor in the irreversible mining of the soil humus, the trade-offs in higher food prices.
At any rate, ethanol is here to stay. I think that other grains might also be sucked into the mix. I’d hate to see a lot of the set-aside CRP lands put back into production, fence row to fence row to just make more ethanol to put in our cars. It would make a lot more sense to make more fuel efficient cars, that to plow up all of our lands.
riffcon on 04/25/2007 at 12:29 PM
2
ER
Chad on 05/25/2007 at 11:46 PM
6
Farmers, unfortunately, seem to be a stubborn bunch - I am one, who resist change. this is actually a definition of most of the US. Most farmers I spoke with last year, June 2006, had never heard of ethanol. They didn't know anything about it and that they could help produce it. But since the ethanol manufacturers kept stressing how much more they could sell their product at, for a higher profit, they flocked to the idea.
CHeck back in your history about the total domestic production of corn in this company over the last 100 years. You'll see a huge expansion from other crops to corn in the 40's (WWII), so much so, the government started paying farmers NOT to grow corn! We flooded the market and then, with such a surplus that couldn't all be shipped out, we had to invent new ways to use it. Compare this overstock of corn in the US versus the price/production rate of Coke and Pepsi and other HFCS users and you'll see some wonderful trends.
Back to the farmers last year, no one ever talked about how selling their corn for a higher profit would effect the price of almost every foodstuff available on the market. A minor side efect no one thought of or simply forgot to mention.
rodrigoesborges on 04/01/2008 at 7:54 AM
1