BETTER BIOFUEL: The plants that grow naturally on fallow agricultural lands could make better biofuels than crops.
Image: © J.E. Doll, Michigan State University
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A mix of perennial grasses and herbs might offer the best chance for the U.S. to produce a sustainable biofuel, according to the results of a new study. But making that dream a reality could harm local environments and would require developing new technology to harvest, process and convert such plant material into biofuels such as ethanol.
Biofuels have become controversial for their impact on food production. The ethanol used in the U.S. is currently brewed from the starch in corn kernels, which has brought ethanol producers (and government ethanol mandates) into conflict with other uses for corn, such as food or animal feed. Already, corn ethanol in the U.S. has contributed to a hike in food costs of 15 percent, according to the Congressional Budget Office, and the U.N. Food and Agriculture Organization blames corn diverted to biofuels for a global increase in food prices.
To see if nonfood plants could be a source of a biofuel the way corn is, researchers followed six alternative crops and farming systems in so-called marginal lands over 20 years, including poplar trees and alfalfa. Such marginal lands face challenges such as soil fertility and susceptibility to erosion.
The new analysis found that conventional crops such as corn had the highest yield of biomass that can be turned into biofuel on marginal lands, although their ability to reduce CO2 is harmed by tilling, fertilizing and other CO2-producing activities necessary to turn them into fuel. (Such factors have caused considerable scientific disagreement over whether ethanol from corn delivers any useful greenhouse gas reductions, although the researchers find that even corn provides some climate benefits as long as oil production and combustion is included in the comparison.)
In contrast, the grasses and other flowers and plants that grow naturally when such lands are left fallow—species such as goldenrod, frost aster, and couch grass, among others—can deliver roughly the same amount of biofuel energy per hectare per year if fertilized, yet also reducing CO2 by more than twice as much as corn. "When biofuel is produced from such vegetation, the overall climatic impact is very positive," says lead researcher Ilya Gelfand of Michigan State University. The research was published in Nature on January 17. (Scientific American is part of Nature Publishing Group.)
By taking those field results and feeding them into a computer model that calculated how much such marginal land was available within 80 kilometers of a "potential biorefinery," Gelfand and colleagues found that 21 billion liters of cellulosic ethanol could be produced in this way per year from roughly 11 million hectares of currently fallow land in 10 Midwestern states.
Such a glut of cellulosic biofuel, if realized, would reduce greenhouse gas emissions—compared with oil that otherwise would have been burned—by 44 teragrams (44 billion kilograms) per year. That is "the same as the CO2 emissions from 10 million medium-sized cars, each with an annual run of 20,000 kilometers," wrote climate researchers Klaus Butterbach-Bahl and Ralf Kiese of the Karlsruhe Institute of Technology in Germany in a commentary on the research, also published in Nature. It would also satisfy 25 percent of the 80-billion-liter target for cellulosic ethanol production in 2022 set by the U.S. government in 2007.
"It is good that the authors are attempting to focus on land that is not already used for food production," says agricultural expert Timothy Searchinger of Princeton University, who was not part of the study. But the research suggests that even if researchers maximized the capacity to grow biofuels on all marginal lands, "the amount of cellulosic ethanol it could produce is only enough to provide 1.5 percent of U.S. transportation fuel by 2020." And the expected yields are about 20 percent less than predicted by a U.S. Department of Energy analysis of biofuel potential in 2011.
Such cellulosic ethanol from native plants would also require technological breakthroughs to efficiently convert plant leaves, stems and other inedible parts into fuel. Whereas a few such cellulosic biorefineries are being built or exist at the prototype scale, none have the capacity to cope with such a mix of perennial grasses and herbs. In fact, one of the key needs for such sustainable biofuels to move forward remains "a profitable biorefining process," Gelfand notes, along with a better understanding of ecological impacts. As it stands, such cellulosic biorefineries get their materials either from the residue of conventional crops, such as corn stover, or from harvesting trees.
Turning marginal lands into biofuel farms could also have a negative impact on the local environment. Marginal areas are often currently set aside for conservation, both as a means to provide a habitat for wildlife as well as a way to protect it from agricultural runoff into waterways.
And, even if such cellulosic ethanol became a reality, it might still come into conflict with food production. "If fuel became sufficiently valuable, it might well displace food crops, as is now the case with corn grain ethanol," Gelfand says. But "expanding fuel production to marginal lands not suitable for food production is a way to relieve the pressure on productive cropland to produce fuel."
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22 Comments
Add CommentThis is another article on biofuels generated by Academia without regard what is happening in the real world and the most important factor; profit. There are many reasons why "marginal" land is marginal and not producing a crop today. It is impossible to "feed" those acres into a computer and expect a rational conclusion on potential production. Land preparation, soil type, location, accessibility, slope, field size and cost are all factors that make each parcel unique and impossible to generalize. While there is potential to create crops that will maximize biomass yield on poor land, it will always require increased inputs as well as producers who will recognize the potential profit in operating those acres. Even then, farmers will respond to the market and grow the crop that promises the greatest return.
Reply | Report Abuse | Link to thisWe should finally put to rest the requirement for "technological breakthroughs" when we describe cellulosic biofuels. Ineos has completed an eight million gallon per year plant in Florida using waste products. Abengoa, POET and Dupont/Danisco are all building 25 mgy plants in the Midwest using crop residues, primarily corn stover. The technology is here and will only get better as these plants begin commercial production next year.
The Department of Energy has documented more than 100 million tons of corn stover per year that can be harvested without impacting erosion or fertility. As corn yields increase the amount of corn residue also increases, leading to tillage problems. Fortunately, removing 3 tons of stover will facilitate no-till farming, greatly increasing organic matter, micro-organisms and fertility, while decreasing carbon loss to the atmosphere.
Corn stover is available in huge quantities today and we are making great strides on how to harvest and store it. Collecting 400,000 tons of stover between harvest and winter with variable weather can be a challenge. Fortunately, our farmers, equipment manufacturers and agribusinesses will be up to the task as they lead the world in innovation and productivity.
Larry Johnson
Can Mary Nichols and Governor Brown support a BP GMO fuel ethanol waiver? Motorcycle, Classic car, Lawn tool engines, Boat, & the beef just might like a choice, a waiver.
Reply | Report Abuse | Link to thisThere may need to be a zoning restriction on farm lands to ensure that food production isn't diminished. Land suitable for food production should be zoned exclusively for food or feed production.
Reply | Report Abuse | Link to thisOther cellulosic sources like wheat/oat/barley straw will also reduce the input costs of methanol/ethanol production. But the problem with using these kinds of sources like corn stover is that eliminating them from reintegration into the land ultimately means the land will need fertilizer to replace them anyways.
Reply | Report Abuse | Link to thisGood comments!
Reply | Report Abuse | Link to thisThere's some fundamental reasons why marginal lands are marginal - any harvesting of them would not be sustainable, for a couple of years, maybe, and destroy some of our few remaining (somewhat) undisturbed natural ecologies.
There is a company in Canada called Iogen that has enzymes to help make cellulose ethanol. They have been at it for years and Shell invested big money in the company years ago. I believe they are still in operation. Check them out.
Reply | Report Abuse | Link to thisThis is so stupid!!! Fossil fuels are not needed except to keep everyone trapped in a carbon producing machine. Nicola Tesla drove from NYC to Buffalo and back with an antenna. NO FUEL!!!
Reply | Report Abuse | Link to thisAlthough the conversion process would be so efficient, to use a gallon of dirty fuel, to make one of bio fuel: would be useless.
Reply | Report Abuse | Link to thisAnyway we need clean energy to produce clean fuels.
And precipitate liquefied gas from the methane produced at the output of hydraulic turbines, is the best solution to get clean and renewable fuels. O for industrial raw material.
And the perfect energy is: the OCEANOGENIC POWER.
Ethanol biofuel is ridiculous. You need more energy to produce ethanol than its energy content. Just burn agricultural waste in steam turbine plants. That's low tech and more energy efficient.
Reply | Report Abuse | Link to thisDr. Strangelove, congratulations you have a basic understanding of the 2nd law of thermodynamics. Ethanol is a energy storage medium unlike fossil fuels which are a source of energy. So, yes, whenever you use an energy storage medium it will always get less energy out of it than you put into it. The hope is that the energy you put into it can be derived from clean energy sources such as wind and solar. Energy efficiency is not the only issue, the issue is economics. The most economically feasible solution may not be the most efficient. The fact is, the sun and wind provide us with more than enough energy for our needs, the issue is how to cost effectively capture it and store it.
Reply | Report Abuse | Link to thisThat is sensible, and probably will eventually be done when all the other plans either don't work, or are so expensive that they need to have massive governmental subsidies to stay alive.
Reply | Report Abuse | Link to thisI do think perennial grasses and herbs are more energy efficient than planting corn which requires fertilizer, and irrigation, as well as probably extensive pesticides and cultivation or chemical weed control. It's has become essentially a starch factory out on the south 40.
Reply | Report Abuse | Link to thisProbably one of the biggest ongoing problems is the fixation on ethanol, which has low heat content compared to gasoline and requires either starch for fermentation or else almost pure cellulose, if the proposed cellulosic ethanol production cycles actually are financially and technically possible and can be scaled up to industrial production.
Methanol would actually be much simpler to produce using biofuels, and is already in wide spread production from coal.
There is a straightforward industrial process for converting methanol to gasoline which has been in use in New Zealand since the 80's using zeolite based catalysts and I think a plant is likely in development in China, since I read about them building a plant.
China has been on a methanol economy for some time now using large amounts of methanol converted from coal and is used as a liquid fuel, even for fueling vehicles and all types of liquid fuel uses. It does have it's problems and I read of a methanol tanker truck having an accident with fire, and I think injuries or deaths, so there are hazards as well as toxicity, methanol causing blindness, however people should not be drinking this stuff, either the ethanol from cellulosic biofuel production or even gasoline. Usually the alcohol proposed as a fuel additive for gasoline, to improve oxygenation and octane. Methanol, rather than being an additive, can actually be converted to gasoline, and used directly, so we would be less dependent on importing oil from politically unstable areas of the world, off shore drilling and even arctic sources such as the North Slope,
It would have more than one source, coal, while if there is a bad drought year, like this last one where a lot of the corn crops were just plowed under since the corn died due to heat and drought in July. So much for biomass and then where would we be.
An industrialized economy requires millions of tons of commodities on a regular, uninterrupted basis to keep operating and supply, food, clothing, shelter, and transportation for about 6 billion people on the planet.
Biomass can only contribute to, not replace the energy needs of the planet.
I moved to a small town in Missouri this past year where the surrounding fields are largely devoted to corn. We also have a local bio-fuel plant. Of course this past year we had a serious drought as well, with Missouri exports exceedingly low. And the production of corn also relies rather heavily on Monsanto products, chemically and in the chosen seed.
Reply | Report Abuse | Link to thisSo, my question is, how can we not diversify as a policy in food production to a broader variety of plants, considering the world's great need for food? And why would we use good acreage and bad to plant corn alone? In fact the up and coming methods of transportation rely more heavily of battery power, which can be obtained through solar power on vehicle roofs more efficiently and less polluting than any bio-fuel.
Some years ago I read that in Amsterdam the public transportation trains are powered by solar panels too. In the USA public transportation and everything else is powered by private corporation donations to elections. This is one aspect that a scientist may have difficulty with out loud and in print, in my opinion.
http://www.science20.com/news_articles/converting_solar_power_car_miles_which_better_photovoltaic_or_biofuels-101124
Reply | Report Abuse | Link to thisI read the article expecting to find a list of plants that could replace corn as a viable crop for ethanol production. Alas they are no technological breakthroughs to allow this to happen. If there were any, it would already be happening.
Reply | Report Abuse | Link to thisScientific American is quick to criticize what works and quick to glorify what doesn't work. What technological non-breakthrough will SA alert us to next. Give us another turkey, served with all the glorious miss-leading headlines for our tired eyes to feast on.
Reading this was a waste of my time. Why not just start a turkey of the month column.
Excellent article.
Reply | Report Abuse | Link to thisFortunately in the debate on Food Vs Fuel,there are alternatives for biofuel production to Sugarcane and Corn – Agave. Agave is a care-free growth plant. What is more it is regenerative. It can be brown in vacant and waste lands in developing countries. Mexico is pioneer in biofuel production from Agave.
What’s more, agave might even benefit from higher atmospheric carbon dioxide levels and increasing temperatures, according to researchers at the Colegio de Postgraduados en Ciencias Agricolas (Postgraduate College of Agricultural Science) in Texcoco, Mexico and the University of California. Agave can use higher levels of carbon dioxide in the air than many other plants, and it has adaptation to living in the desert.
Agave uses a metabolic technique that greatly reduces water loss. The plant uses a process calledcrassulacean acid metabolism (CAM). In CAM, a plant stores carbon dioxide absorbed at night, then uses it during photosynthesis in the daytime.
By inhaling carbon dioxide only at night, agave can keep the opening on their leaves, called stomata, closed during the heat of the day. That saves a tremendous amount of water compared to crops like corn, a C4 plant.
The CAM process is also what allows agave to use higher levels of CO2 than crops like wheat, barley, and potatoes, which are known as C3 plants.
Agave could reduce the food vs. fuel debate as well. Agave grows in areas where corn would wither and sugar cane would shrivel. It’s adapted to nutrient-poor, arid lands, so growing agave doesn’t compete with food and fiber crops.
Another care-free growth plant is Opuntia. Opuntia produces biogas and this in large quantities can be used for power generation. Already biogas generators upto 1 MW size are available from China.
Dr.A.Jagadeesh Nellore(AP),India
E-mail: Anumakonda.jagadeesh@gmail.com
It is more economical if the biodiesel comes from wastes such as used cooking oil, animal fats; biogas from human, pig and cow manure. Food vs. fuel is foolish. Fuel from waste is smart.
Reply | Report Abuse | Link to thisCollection is a problem which reders the process uneconomic.
Reply | Report Abuse | Link to thisDr.A.Jagadeesh Nellore(AP),India
Converting biomass to ethanol is very inefficient. 'Biomass pyrolysis' converts every part of a given biomass into 'biochar' & hydrogen, or biofuels. The technology is now receiving big investments from major oil companies and has the advantage that it sequesters CO2. Look it up on your search engine....
Reply | Report Abuse | Link to thisFirst, lets remember current generation biofuel from corn doesn't just make biofuel. An equal part of the process leaves a high protein animal food. Yes that is right, its not food vs. fuel, its both. In fact many animals are fed corn, that ideally wouldn't be. Part of the reason is many species don't take well to the high starch content in corn. Corn ethanol uses the starch, but leaves the protein, fiber and fat unuses. The protein fiber and fat are all sold as animal feeds. The fat can also be used as a biodiesel feedstock. Also CO2 from fermentation can be used by soda companies, as an acidifier for waster water effluent, or for freezing and dry ice. FOr stover, as fields get more densely planted, stover will have to be removed, otherwise the excess stover inhibits new crop growth the next year. So taking 1/3 of the stover off current fields is not a bad thing, taking all would be, but nobody who is going to do cellulosic ethanol is going ot do that. I really think it would be good for people to do just an ounce of independant research before posting.
Reply | Report Abuse | Link to thisAs I understand, it has been widely established that diverting land used to produce food for producing fuel results in increased food prices. Unless Fuel can be produced using agricultural waste that is not currently used for food for humans or livestock, food prices will be negatively impacted.
Reply | Report Abuse | Link to thisThis article reports a study intended to address those concerns, by finding ways to produce non-food crops on land that is not used to produce food.
"To see if nonfood plants could be a source of a biofuel the way corn is, researchers followed six alternative crops and farming systems in so-called marginal lands over 20 years, including poplar trees and alfalfa. Such marginal lands face challenges such as soil fertility and susceptibility to erosion."
Perhaps you should have read the article?
or perhaps you should do some research about how many acres are being used for food production. There are now less acres in production on total than there was 10 years ago. It is a huge misconception that all the corn being planted is for food. In fact there wouldn't have been nearly the acres planted if the government didn't hugely subsidize farmers, especially in the 80's. We as tax payers were paying for corn to rot in bins, on ocean transports. Also the majority of corn grown in the us is number 2 yellow corn, not white corn. White corn is for human consumption, yellow corn is for animal consumption. Most places, such as Africa and South America will refuse to eat yellow corn, it is not used to make tortilla's there. The feed product coming out of current generation plants takes out a small component of the corn, one many species don't utilize well. What is left is a feed that is 3 times the protein. This allows for animals to go to the market sooner, thus reducing feed cost for the animal, not raising it.
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