Pretreated Biomass for Food and Fuel

Bruce Dale urges careful thought about energy and agriculture.
By Susanne Retka Schill | June 26, 2013

A 1-ton-per-day pilot facility on the campus of Michigan State University geared up this spring to produce pretreated biomass for feed trials. It’s part of a demonstration that professor Bruce Dale hopes will show others how pretreating biomass for feeding animals can be successfully integrated with biofuels production, ultimately producing both more food and fuel. 

While ethanol skeptics claim it’s obvious that food needs trump the use of agricultural resources for fuel, Dale will tell you biofuels are not optional.  As a scientist, he’s ready to back that up with data-based reasoning. His motivation, though, comes from his childhood, growing up in the copper mining town of Ruth in eastern Nevada and seeing what happens when the mine runs out and a ghost town is left behind. He thinks of that when he considers our country’s dependency on oil. “Copper is potentially recoverable and recyclable,” he says, “but when you burn oil, it’s gone.” 

Dale is far from a doomsday prophet, however. “I’m an optimist. I’d much rather have an optimistic view of the future and try to figure out how to get there.

”In a recent conversation with Ethanol Producer Magazine, Dale expounded on his vision for an agriculture that sustainably provides food, feed and fuel. As a professor of chemical engineering at MSU, Dale is known for a biomass pretreatment process dubbed AFEX, for ammonia fiber expansion. He is also known for his strong advocacy for biofuels, receiving the International Fuel Ethanol Workshop & Expo’s Award of Excellence in 2011.

Dale recently co-authored a peer-reviewed paper for the Council for Agricultural Science and Technology called “Food, Fuel, and Plant Nutrient Use in the Future,” along with an economist, a plant nutritionist and a soil scientist. The authors conclude the world will be capable of meeting its needs for food, fuel and fiber in 40 years, and biofuels can play a key role in fostering more efficient use of land resources.

Looking ahead to 2050, the paper finds that adequate world food production cannot depend upon expansion of harvested area. “Instead, scientists and food producers need to look at the way land is currently used and the best practices for how to move forward,” the CAST committee writes. The paper examines population dynamics, food demand, land use and productivity and the impact of energy and biomass production. The authors include Dale, David Zilberman, department of agricultural and resource economics, University of California-Berkeley, Paul Fixen, International Plant Nutrition Institute, Brookings, S.D., and John Havlin, department of soil science, North Carolina State University.

There is a clear relationship between a country’s wealth and its access to cheap energy, the paper says, pointing out that the “the age of stable, cheap oil is over.” As fossil fuel supplies shrink relative to demand, price volatility is likely to increase. “The world has had cheap food in no small part because it has had cheap energy, led by cheap oil. The production, processing and distribution of all agricultural and food commodities are intimately linked with the price of energy.” 

Energy Services
The importance of biofuels is underestimated, Dale suggests, in large part because people haven’t been trained to think carefully enough. “They just talk about energy, but we don’t pay for energy. What we want are the services energy gives us.” If we paid for energy, he points out, the cost of a Btu would be equal, regardless of its source. Instead, we pay about five times as much for a Btu of oil as for coal. Of the three primary services provided by energy, two—heat and electricity—have multiple options to complement petroleum: natural gas, coal, nuclear, hydro, solar, wind or biomass. But for the third service, mobility, fully 96 percent comes from petroleum, with the remainder coming from biofuels and compressed natural gas (CNG). 

CNG and electric will play a role in the future, he adds, but both have limitations. “[Electric vehicles] don’t have the power-to-weight ratio. It’s a matter of physics. You can’t pack enough energy in a battery to do certain types of things. You can’t get a jet aircraft off the ground with a battery. You can’t run a long-distance trucking fleet very well on batteries.” In addition, CNG is likely to be more widely utilized only by truck fleets, partly because engine conversions and refueling stations are extremely costly. 

When thinking carefully about energy, ethanol’s value is much greater than when considering just its energy return on investment. Dale points out that most of the energy used in ethanol production doesn’t come from petroleum, but rather natural gas. “What you get for liquid-out for liquid-in is 20-to-1 for ethanol,” he says. 

“That’s why biofuels, liquid fuels from plant material, are so critical,” he explains, largely due to the potential to significantly scale up production. “It’s going to be difficult for grains to do it at large scale, but it’s not difficult to do with cellulosic at large scale—it’s grasses and trees, woody material.” Many of the cellulosic feedstocks being considered have multiple benefits, he adds. “If we take reasonable care with how we grow them, how we develop them, then over time you get better water quality because perennial grasses improve water quality. You get more fertile soils because grasses improve soils. You get a lot of greenhouse gas (GHG) reduction because they are essentially carbon neutral and, if they are building up soil organic matter, they are probably carbon negative.”

The concerns raised in opposition to biofuels, including food versus fuel and land conversion impacts, are also not being thought through carefully, he says. “Agriculture today is nothing like it was 50 years ago, or 100 years ago,” he says, and it will change again. It isn’t hard to imagine a configuration for agriculture that would provide more food, more fuel and more environmental benefits.  “It’s actually quite easy to image win-win-win scenarios once you start thinking that way.”

Dale lays out a vision for the agriculture of the future that will use land resources more efficiently. He points out that currently 85 to 95 percent of U.S. agricultural land is used to feed animals, and not to feed humans directly. There are a number of ways in which biofuel production can utilize biomass resources without competing with feed use, and actually enhancing supplies. Biofuel production would allow the early harvest of feedstocks such as alfalfa and grasses when the protein content is high, utilizing the cellulosic fraction for biofuel production and concentrating the protein for animal feed. Additional feed protein can be coproduced with biofuels via the spent yeast. In addition, a ready market for biomass would stimulate double cropping, turning cover crops utilized for their environmental benefits into cash crops. 

Biomass Processing
Dale envisions the development of regional biomass processing depots that serve both the livestock feeding and biorefining industries. MSU is part of a research effort looking at ways of converting biomass into dense, stable, shippable intermediate commodities with uniform characteristics. Also researching the concept are Iowa State University, Idaho National Laboratory and Pennsylvania State University.   

At MSU, a pilot facility began operating in late May, making feed pellets from AFEX-treated biomass. “I’ve always known it would increase the animal feed value,” Dale says of the pretreatment process he and his colleagues have developed and refined over three decades. They are getting a boost from the Michigan Biotechnology Institute, formed at MSU to help move the commercialization process forward on university research. “They’ve made some notable advances in reducing the cost of the AFEX process and because of what they’ve done, we’re now in a position to commercialize animal feed first,” Dale says. “Then we can use the animal feed markets as a pull-through for the biofuels market.” 


MBI obtained more than $5 million in funding from the U.S. DOE and the MSU Foundation to build a pilot-scale AFEX reactor at its facility in Lansing, Mich. The goal is to produce 10 to 15 tons of AFEX-treated biomass, which will be used in large animal feed trials being led by Stephen Rust with the MSU animal science department. “After pretreatment, we pelletize the material and it essentially has the behavior of corn,” Dale says. “It’s as dense as corn, it’s stable like corn, it flows like corn.” He adds that preliminary feed trials indicate it will have 80 percent of the value of corn in convertible sugars. 

“If all goes well—and we have smaller-scale ruminant feeding tests that show us it will—there’s a lot of people who are interested in licensing it. We intend to license it very broadly and let as many people use it as want to,” he says. Ultimately, building a base market as livestock feed will allow the supply of pretreated biomass pellets to build to a point where a biorefinery would be assured of sufficient feedstock, solving the chicken-and-the-egg problem of building out the cellulosic ethanol industry. 

A Challenge
Dale lays out a challenge to the ethanol industry—both the corn-based and nascent cellulosic industry. “We need to start being proactive in the development of these fuels,” he says. “The thing is, in the U.S., the people who have the most easily converted and most abundant cellulosic material are the corn farmers with corn stover.” It is essential that corn stover for biofuel be done right, he emphasizes. He also thinks there is an opportunity to promote double cropping as a way of tapping into the benefits of cover crops while growing biomass for biorefineries. 

He urges biofuel producers and farmers to “start embracing a positive vision of the future.” The vision to communicate, he suggests, goes like this: “We understand the environmental concerns, we want to improve the environment too. We're going to start harvesting our corn stover, and at same time we’re going to plant cover crops and double crops. We’re going to build up soil organic matter, reduce erosion and we’re going to trap some of those nitrates so they don’t get into water and head down to the Gulf of Mexico.”   

Globally, similar systems for animal feed coupled with biofuel production can play an important role. “We underrate people’s ability to produce from the land if they have the right incentives and the right tools,” Dale says. Well-intentioned hunger programs of the past that distributed cheap surplus U.S. grains in developing countries had the unfortunate side effect of undermining local agricultural systems. “Here’s the bottom line. Those are places that are essentially without fossil fuels. They’re too late. They’re not going to get into the fossil-fuel bonanza. We will have burned it all up before Malawi or Mali or Kenya or other places in Africa and elsewhere ever get the chance,” he adds. “The only way they are going to develop and have the living standards we take for granted is to figure out how to produce sustainably—and that means in an environmentally sound way—lots of liquid fuels. That’s only going to come from plant matter. As we get this industry going, we’re going to see some very interesting side benefits for countries that don’t have much in the way of liquid fuels. It will help jump-start a lot of economic development there, in the same way that having the cheap petroleum for so many years did here. It’s not cheap anymore, so we’re suffering from that now. But a lot of places that aren’t blessed with the petroleum we’ve had will be able to grow their own fuel. And, because they’ll be incentivized to do it in a land-efficient way, there will be more food as well.” 

These systems won’t be instantly perfect and mistakes will be made, he predicts. Also, one of the lessons of the past is that productive agriculture often produces price-depressing surpluses for which biofuel production provides an alternative market. “We’ve learned people can only eat so much, but there’s apparently no limit to how much we would like to travel around if we could,” he quips. 

Author: Susanne Retka Schill
Senior Editor, Ethanol Producer Magazine


2.5 x more biomass possible

An analysis cited in the Council for Agricultural Science and Technology paper, “Food, Fuel, and Plant Nutrient Use in the Future,” shows that total biomass production potential, including both grain and cellulosic biomass, could be increased 2.5 times over current levels. “This is enough biomass to produce approximately 400 gigaliters of ethanol per year, roughly the energy equivalent of all imported petroleum used for gasoline production, while still providing all the food and feed currently produced on this acreage. This approach to integrated food and biofuel production also decreases total U.S. GHG emissions by approximately 700 teragrams carbon dioxide equivalents per year, roughly 10 percent of the total U.S. GHG emissions.”