November 18, 2006
Ethanol From Wood Chips As Cheap As Corn Ethanol?

MIT's Technology Review reports a company is going to build a demonstration plant for a technology which they claim will produce ethanol from wood chips as cheaply as ethanol from corn.

Experimental methods for converting wood chips and grass into ethanol will soon be tested at production scale. Mascoma Corporation, based in Cambridge, MA, is building demonstration facilities that will have the capacity to produce about one-half to two million gallons of ethanol a year from waste biomass. The startup recently received $30 million in venture-capital money, which is fueling its scale-up plans.

Mascoma is genetically engineering microorganisms to do part of the work to convert wood into simple sugars. They say at the current state of their technology their production cost will be similar to that of corn ethanol. They expect further development of their technology will cut their ethanol production cost in half.

Corn ethanol does not scale. Whereas some experts think wood ethanol could scale all the way to a total replacement for gasoline.

Corn grain, the current source of ethanol in the United States, requires large amounts of land and energy to produce. This, along with the demand for corn as food, limits the total amount of ethanol that can be produced from corn to about 15 billion gallons a year--about three times what is currently produced. If the fuel is to supplant a sizable fraction of the 140 billion gallons of gasoline consumed each year in the United States, ethanol producers will need to turn to biomass such as wood chips and switchgrass. These resources are cheaper and potentially much more abundant, and they can be converted to ethanol much more efficiently than corn can because they require less energy to grow (see "Redesigning Life to Make Ethanol").

Since ethanol has less energy per gallon than gasoline that potential 15 billion gallons of ethanol amounts to only 10 billion gallons of gasoline or one fourteenth of current US gasoline consumption. Since demand is rising it represents an even smaller fraction of future demand and does not address demand for diesel, aircraft fuel, and other uses of fossil fuels.

Biomass from wood and other sources might be able to replace all gasoline in the United States.

Indeed, ethanol from such sources could replace "a very large fraction" of the gasoline currently used for vehicles, says Gregory Stephanopoulos, professor of chemical engineering at MIT. He says some experts estimate that with gains in efficiency and high yields of ethanol, all the gasoline for transportation could be replaced; the most conservative estimates say that about 20 percent could be replaced.

As I read the continuing series of reports on advances in biomass technology I'm starting to get a sense that the people who are fighting to prevent global warming are fighting yesterday's battle. Biomass energy is going to drop so far in price that ethanol will replace most of the current uses of gasoline and diesel fuel. If that happens then environmentalists will need to start worrying about how much of the world's landmass will get shifted into production to produce biomass for energy.

My guess is that wood biomass will be less disruptive for animals and insects. Trees take years to grow. So once planted the area they occupy will provide habitat for species that can migrate in. But I'd like to see analyses on the likely effects of large scale tree biomass energy from people with expertise on habitats. Will even savannahs get planted with trees and will a large number of types of habitats become monocultures that support a smaller range of plants and animals?

Harvard environmental studies professor Michael McElroy argues the United States does not have enough land to scale up ethanol production all that much.

Some 73.4 million acres of land were harvested for corn in the United States in 2004—23 percent of the nation’s total cultivated land area. Anticipating the demand for additional corn for ethanol, the futures market currently projects a 25 percent increase in the price of a bushel of corn for 2007. How will farmers respond to this incentive? There are two possible options. One is to increase the total planted area. The second is to favor corn over alternative crops, such as soybeans. But soybeans are already in short supply globally, and there are plans to use them as a source of biodiesel fuel as well. And if we opt to expand the total cultivated area, we will have to open up much less productive acreage for cultivation, with presumably higher applications of fertilizer and additional reliance on irrigation. Neither option is attractive in terms of either economics or the implications for environmental quality. At a minimum, we should expect higher prices for the production of either ethanol, or food, or both (corn and soybeans are essential components of animal feed in the United States).

I've done rough calculations in previous posts where I figured out how much land mass it would take to grow enough corn to replace all oil and natural gas in used in the United States. The rough estimate was well over a third of the US land mass assuming that production yield on the additional acres would be as high as the 160 bushels typically seen on existing corn acres and under cultivation in the United States. But of course the additional acres would have far lower productivity. Plus, the pesticide run-off, the additional demands for irrigation water, and other problems with scaling up makes corn ethanol completely impractical as a major source of energy.

Some existing ethanol production plants get 2.6 gallons of ethanol per bushel of corn. I've seen claims that some plants get 2.7 gallons of ethanol per bushel and an announcement for a technology that might boost the ratio to 2.8 gallons per bushel. Multiply by two thirds to get the energy equivalent for gallons of gasoline.

Suppose we imagine a future technology that'll extract 3 gallons of ethanol per bushel of corn. That's like 2 gallons of gasoline. Then an acre would produce 2 gallons times 160 bushels or 320 gallons of gasoline equivalent energy. But there's an unresolved controversy as to how much energy input is needed to produce the bushels of corn in the first place. Some fraction of the ethanol output would need to be fed back into agricultural production to make the corn. So the net energy yield per acre of corn is probably far less than the equivalent of 320 gallons of gasoline per acre and might even be less than 100 gallons.

Now consider the 140 or so billion gallons of gasoline that the United States consumes per year. At 100 gallons per acre we are talking 1.4 billion acres to produce enough corn to make enough ethanol to replace gasoline. But the United States contains only 2.3 billion acres and some of that is desert and in Alaska and in areas where there's not enough water for farming. You'll find arguments for scaling up biomass production in sunnier Brazil where farms could operate all year round. But aren't the rain forests in Brazil already getting cut down too fast for other purposes?

Trying thinking about what ethanol means for a place like India which has 10 times the population density of the United States. An industrializing India that joins a worldwide move to biomass energy would put such a large fraction of its land under cultivation that you can just plain forget about the survival of any rare big cat or primate species outside of zoos. Fuggedaboutit. The way FuturePundit sees it biomass energy is a bigger threat to wildlife in the 21st century than is global warming. We ought to be thinking about how to accelerate nuclear power and photovoltaics as ways to save wildlife habitats and slow the rate of extinction of species.

Share |      Randall Parker, 2006 November 18 03:38 PM  Energy Biomass

ScottyB said at November 18, 2006 8:01 PM:

Woody biomass crops used are sometimes fast growing poplar hybrids, typically on a 7 year rotation. Even still, they don't get very big before they're harvested. I don't have the numbers in front of me, but I don't think the annual poplar biomass yield per acre is higher than that of miscanthus, which might be the current reigning yield champ.

I am also concerned about excessive land use due to a booming biomass industry, and think it would be wise to properly plan a balance between food, biomass, and recreational land use. Can the economic markets be trusted to decide this?

Also I agree that other energy sources need funding and development. This has to be a multi-pronged approach. My impression here in the Midwest is that your Average Joe thinks ethanol will solve everything. People think a silver bullet exists. But we also need dramatic improvements in conservation, along with biomass alternatives.

back40 said at November 18, 2006 10:14 PM:

If you have the tech to get ethanol from cellulose - the tree, switchgrass etc. trope - then you should look at the mass of the whole corn plant rather than just the bushels of grain yield. Corn grown for that purpose wouldn't be the same as that grown for grain, it would be cultivars that produce large, leafy plants - something closer to what is now grown for silage. The total biomass yield of improved varieties developed for energy should be used for comparison to get a more accurate picture of possibilities.

This is just a tech neep - your main points are unscathed - but it would strengthen the argument to include such considerations. One of the arguments corn advocates use is that we know a very great deal about corn and can swot up a new variety quickly, and already have an industry in place to do so. Corn has been a pretty marvelous c4 grass that has been bred to do a wide variety of things - not just the field corn that is currently dominant. They have a point. I suspect that work is already in progress to engineer some sort of variety that could be preferred by those producing for fuel markets.

Wolf-Dog said at November 19, 2006 2:44 PM:

With genetic engineering, it is almost guaranteed that in the near future there will be many hardy and fast growing plants that will grow in desert areas, or regions that are not useful for agriculture. Thus I do not think that biomass energy will be an environmental problem, on the contrary, biomass farming for fuel, will actually reduce or at least recycle carbon dioxide in the atmosphere.

The danger, however, is that next year there will probably be a temporary glut of oil, and combined with the intentional manipulation by OPEC, this may lead to an avalanche of bankruptcies for the alternative energy companies which are very vulnerable now, which is what the OPEC wants.

Garson Poole said at November 19, 2006 10:23 PM:

Growing and harvesting biomass using current technological capabilities would require vast areas of land to generate substantial amounts of energy as Randall notes. Solar would also require many square miles of land (or rooftops) to provide a substantial energy output. However, there is a technology that promises a much smaller land footprint. Large wind turbines can be placed on floating platforms at sea. The platforms can be located offshore at a distance that minimizes any visual impact.

There has been substantial opposition to offshore wind projects such as “Cape Wind” which has a proposed location in Nantucket Sound off the coast of Massachusetts. Yet, floating platforms can be located further away from the coast so that politically well-connected and wealthy seaside residents are unlikely to raise an alarm. General Electric is one of the major wind turbine manufacturers that is pursuing this idea along with other companies and researchers.

The magazine Technology Review discussed this approach in an article entitled Giant Wind Turbines with the summary “Floating wind farms placed far offshore could lead to affordable electricity -- without cluttering the view.” Here is an excerpt:

Huge turbines mounted on floating platforms could make wind power competitive with fossil-fuel-generated electricity. These advanced wind turbines, which are in development, could be situated far from the shore, too, avoiding battles with onshore residents who object to the presence of large wind farms.
GE has announced a $27 million partnership with the U.S. Department of Energy to develop 5-7 megawatt turbines by 2009, each of which could power well over 1,000 homes. Supplanting the company's current 3.6 megawatt turbines, these giant energy factories should make wind power more economical, since the major cost of building and installing offshore wind farms does not depend primarily on a turbine's size, but on the number of them that need to be erected.
The article ends with a somewhat disappointing claim that wind power could supply 20 percent of U.S. energy needs.

Rob said at November 19, 2006 10:55 PM:

20% of grid power coming from wind is because wind is so unreliable. We want power coming when we want it, even if the wind is not blowing. While electricity can be moved from production to demand, there are big losses at distance. Electricity produces locally can be stored, but that has big losses too, and requires building more infrastructure, like lead acid batteries a couple stories tall. Plugging turbines into the existing grid we can get about 20%, more than that, and the grid needs rebuilding at huge capital costs. A number I see fairly often is $2.3 million per mile of high voltage cable for long distance transmission.

Randall, I want a biofuel proving project: Farm gets X gallons of oil and natural gas. Electricity use is recorded (it does not have to come from coal. After the first year, no more oil or nat. gas. How much biofuel comes out without oil going in? The experiment may be expensive, but not nearly as expensive as the biofuel "Apollo Project" for the subsidy farmers.

How much biofuel/dollar?
How much per acre?

They need to give us proven numbers, not photos of amber waves of grain and flags courtesy ADM.

Garson Poole said at November 20, 2006 3:05 AM:

Thanks for your comment Rob. Yes, the intermittency of wind power is a problem because the electrical grid must maintain stability, and it also must be able to respond to changing demands. One advantage of wind turbines on floating platforms is that the wind farther from shore is stronger and blows more steadily. The Technology Review article claims that the platforms “would allow the turbines to generate power at 50 percent capacity on average throughout the year, compared with 30 percent or less with on-land turbines.”

Rob suggests that energy storage may require “infrastructure, like lead acid batteries a couple stories tall.” But there is another intriguing possibility for storage that is emerging which uses large-scale vanadium-based “flow batteries”. The energy storage capacity of these batteries can be increased by increasing the volume of liquid held in tanks. A new wind farm project in Ireland will include a 12MWh flow battery as described here. The energy storage density is not too impressive but in this utility application the battery is stationary. Randall has championed more funding for battery research and I think that flow batteries are an important avenue to explore.

There is another way to improve the resilience of the power grid. Large numbers of grid connected hybrid and electric vehicles with bi-directional chargers that both accept power from the grid and deliver power could help greatly as discussed in this Renewable Energy Access article.

One company called EEStor has been mentioned in the comments on this blog in the past. They are trying to manufacture ultracapacitors that are supposed to have remarkable properties. If EEStor achieves its apparent goal then electric cars and plug-in hybrid vehicles will be viable. Some observers are dubious about the chances of success, but I hope that they succeed. The most recent article about EEStor that I could find appeared in the Austin American-Statesman on November 5th. The article is entitled Charging into the future. Here is an excerpt:

The company has come up with a new method for making ultracapacitors, battery-like devices that can store large amounts of electricity. EEStor's energy storage unit can hold enough charge to power a car 300 miles, according to its patent, and it can be recharged in the time it takes to pump a tank of gas. And it can do that at only a small, if any, premium to the cost of a gas-powered engine.

Randall Parker said at November 20, 2006 7:12 AM:


The ground footprint to get all power from solar would be a very small fraction of what it would be to get all power from biomass. I've done calculations on this in the past and linked to a Cal Tech physicist David Goodstein's calculations as well.

How big the footprint would be depends on efficiency of conversion. But solar panels world 12 months of a year and even at 10% conversion get far more (probably more than an order of magnitude more) from an acre than plants. Plus, solar panels do not need water and yearly labor and energy to plant and harvest.

50% efficiency solar would probably give us enough power just from roofs and outer walls.

Of course the sun does not always shine. Hence the biggest advantage of nuclear.

But, yes, we need better batteries. We need better batteries to go to nuclear as well. Or we need better hydrogen storage mechanisms. But I see hydrogen as a more distant prospect.

bigelow said at November 21, 2006 12:58 PM:

“The danger, however, is that next year there will probably be a temporary glut of oil, and combined with the intentional manipulation by OPEC, this may lead to an avalanche of bankruptcies for the alternative energy companies which are very vulnerable now, which is what the OPEC wants.” --Wolf-dog

OPEC cares about getting money and getting more money. After the '70s oil boycott alternative energy was making great progress. Carter put solar panels on the White House roof. Then OPEC pumped lots more oil causing the price to crash. Reagan took the solar panels off the White House roof. The alternative energy industry went into the toilet. But today barring world depression, seems the oil glut is already retreating, and by next summer’s driving season ought to be gone. Demand for oil is still increasing, even if it is off slightly here.

Ethanol might make it on the farm as fuel, but not in our cars. Today’s corporate farming model is mostly a factory for converting petroleum into food and fiber. Yields for an ethanol crop without the petroleum fertilizers on factory farms would be low and falling because the soil is basically dead; nothing more than a sponge where the chemicals are dumped on and the crops taken off. To produce a crop without petroleum the soil has to be fertile. To keep soil fertility or restore it is a big deal. Massive withdrawals (crops) must be balanced by deposits (manures, trace minerals). If the ethanol production residue isn’t suitable or goes elsewhere, rather than back on the land, what else goes to maintaining soil fertility in its place?

An all renewable grid system driven by wind and solar would need lots of storage. Options are compressed air, flywheels, pumped water, hydrogen from electrolysis, besides batteries and ultracaps. I thought a totally renewable grid sounded like a good idea once. Using remaining fossil energy inputs we build a renewable system using storage systems, wind, solar, etc and at some point the renewable energy system becomes a closed system with no fossil inputs. If system equipment wears out, it has to be replaced using energy from the grid. Eventually repairs will no longer be a negligible drain on the system, as more energy goes to fix the system, less is available for other uses. Without external inputs like many more nukes, we will all be revisiting the middle ages sooner or later.

Paul Dietz said at November 23, 2006 10:19 AM:

I suspect ethanol will be supplanted as the biomass-derived liquid fuel by more energy dense hydrocarbons. There's a lab-scale process for converting sugars into gasoline-like hydrocarbons that converts 90% of the chemical energy of the input feeds into the output fuel stream. One nice feature is one of the input streams is hydrogen, so if you have a non-biomass hydrogen source you can extend the biomass resource with it.

Randall Parker said at November 23, 2006 2:30 PM:


Sugars are partially oxidized with oxygen in their structure. So it makes sense to use hydrogen to reduce the carbons and knock off the oxygens.

Yes, reducing biomass to make it a more compact energy source is a lot more appealing than going to get refueled more often with less energy dense ethanol.

There are proposals to design nuclear reactors that will rip hydrogen out of water at high temperatures in order avoid the energy loss from generating electricity. Electricity can split water. But there's more wasted energy if the nuclear heat first spins turbines to generate electricity.

Could hydrogen from a nuclear plant fed into a biomass plant using cellulosic technology produce gasoline at competitive prices?

Alternatively, there's wind and photovoltaics for electricity to split the water. But photovoltaics cost way too much. Wind might cost too much as well.

beowulf said at November 25, 2006 7:34 PM:

Of course ethanol doesn't work in existing engines (unless its diluted in a 90% gasoline mix) nor can it be sent through the existing oil pipelines. Butanol research is a better bet, it works as a gasoline substitute and doesn't require engine or pipeline modifications.

W.A. McCormick said at July 29, 2007 11:45 AM:

You can forget the potential "Oil Glut". China is expanding faster than OPEC can dream of Glutting. China needs oil desperately. I fear that they will soon be ready to go to war for it, if it is not available otherwise. What they get currently, they get from Russia, and that is a trickle compared to their need. They need to own the Middle East. I think that our situation is, "Convert fast or face disaster". There is about to be a world oil shortage like we have never seen. All the oriental countries are gearing up in industrials at phenomenal rates, and that requires energy. In China, even the rice farmers have left the farms and gone to town to work in the factories.

As to corn and corn stalks, have you seen a corn farm? The stalks are about 6-8 inches apart, and each stalk has 1 ear of corn on it. There is no way to get more stalk on the land, and I think they have about maximized the grain production too. Corn production has been high tech for many years.

As for biomass availability, capacity is only one aspect. Look at what is being wasted annually in timber harvesting. Logging compainies are leaving the forests looking like war zones. That should be classified criminal. If we just used what is being wasted, we would have much fuel. Crying over whether we can get our total diet out of one cup is silly slobber.

W.A. McCormick
Lindale, TX

W.A. McCormick said at September 29, 2007 11:11 PM:

There is considerable research going on presently with the aim of developing a cheap means of gasifying cellulose, and then condensing it to ethanol. There is a lot of information on this process on the internet, and some claims that it can be done for $1.00/gallon. The biggest negative factor is that a plant would take a huge initial investment. Considering the size of the stakes in this game, that is peanuts. Any state could make that kind of investment, and many big businesses could do so too. The biggest positive factors are the facts that it would convert the cellulose almost instantly and very cheaply, into fuel. There would not be any long delays waiting for fermentation to take place, and the cost would be minimal per gallon. I am not sure how well perfected this process is, but I would like to see some of you comment on it.

W.A. McCormick

Cyrus said at July 10, 2008 7:01 AM:

Any afford to produce bio-fuel or alternatives to be used in combustion engines will be just a short term relief and the demand for energy will be raising to the point that if we plant all the deserts on the earth and dry all our oceans to plant corn won't be enough to supply the demand for energy and still to expensive ad un-efficient to produce.
The energy crises will limit our technological, industrial and urban developments, expansions and growth worldwide and will case international crises and wars if we don't find a realistic energy solution.
Even wind and solar energy are stone-aged to me plus we can't be all over the place.
We have to start developing ways to harvest the energy from electromagnetic fields passing through our planets atmosphere which is enough to supply our todays demands for energy
by billions of times and if we reach that goal it'll take us to the next technological revolution and since that development could take decades we have to focus on nuclear energy.
We were the first nation to develop nuclear energy but haven't develop any new plants in decades just because of publics uneducated concern about the environment.
We have to forget about the public BS about the environmental risks because nuclear is the cleanest efficient form of energy if controlled safely.
We should develop generators using Hydrogen Fusion which is much cleaner than uranium to produce electricity.
Develop safe and clean nuclear powered cargo ships, trains and even cars which you only have to refuel once a year.
The world is running out of copper we waste most of our electricity on the power lines; we have to find cheaper and more efficient ways to transfer electricity.
We have to look back and search for the inventions and inventors that could be a part of our solutions
Find out what happened to Nicola Tesla's inventions promising free energy and no one cared.
We have to wake up and invest in something real.
Email me if you have any comments

K Brown said at July 26, 2008 2:21 PM:

many years ago I remember a discussion of a small fusion reactor suitable to power an automobile. Anyone else remember that? Gatech51

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