EconSouth (Third Quarter 2006)
Volume 8, Number 3
Third Quarter 2006
Q & A
‘Newer Technologies Are Increasing the Ethanol Yield’
An Interview with Joy Peterson of the University of Georgia
An assistant professor of microbiology at the University of Georgia in Athens, Joy Peterson conducts research on biomass conversions for producing fuel ethanol. One of her current projects uses pectin-rich processing residues from citrus, apples, and sugar beets with engineered bacteria as the biocatalysts. Her related projects involve using chemical pretreatments to help decrease the amount of enzymes required to degrade the biomass that converts to ethanol.
EconSouth: What makes ethanol the focal point of so many alternative energy discussions?
Joy Peterson: Liquid fuels like ethanol are the easiest to integrate into our existing structure. They can be burned in the same kind of engine that petroleum cars use. You’d have to watch the quantity because ethanol is a solvent. Anything prior to an E85 car is going to need to have some changes to the areas that might be affected by a solvent, like different hoses. That change is probably the easiest to integrate into our existing structure.
ES: From a consumer standpoint, what other obstacles are there?
Peterson: In Georgia, for instance, we don’t really have the infrastructure yet to deliver ethanol. We can’t use the existing network [pipelines] at that high a concentration. We need a little bit more work on that infrastructure.
ES: You’ve said that you’re optimistic about the study of using feedstocks other than corn to generate ethanol. Why is that?
Peterson: We have newer technologies that are increasing the yield. I’m sensitive to people saying about our research, “Oh, here we go. We already did this. We’re back in the ’70s.” They just aren’t aware of all the new technology that’s come about to make this really doable this time. The economic and environmental drivers have all started to align to propel ethanol production forward, but the technology has come a ways too. It’s a combination of agents and processes. It’s the change in the agents that allows the changes in the process. Look at sugar beets for an example. If you ferment the sucrose, you get so many gallons of ethanol per ton. If you use yeast, you’ll get about 23–25 gallons per ton of the pulp alone. If you use our newer technologies, you get closer to 100 gallons per ton. So when you start to learn about newer technology and apply it to specific situations, the feasibility study that was done maybe five years ago could in some cases be quite different from what that same feasibility study would be today.
ES: Ethanol producers in the Southeast are at a disadvantage using corn as a feedstock because of the cost of transporting most of it from the Midwest. What criteria does a good alternative source of biomass have?
Peterson: You can make ethanol from pretty much anything that used to be some kind of plant material. The questions are, How much do you have? What is the cost to you to get that material? Are you going to have to transport it? How much of it is water? What is your supply going to be? And is that cost going to fluctuate wildly because you just added a value to something? Are you going to drive the price up? What do you have to do to that material to get it to the point where either yeast, engineered bacteria, engineered yeast, or whatever can consume the glucose of the biomass and make ethanol as a waste product?
ES: How do you see ethanol production evolving in the Southeast?
Peterson: There are groups that are not necessarily interested in following the corn model. They would like to have something that they could grow in Georgia, for instance, and make smaller amounts of ethanol, maybe four or five million gallons a year instead of 40 or 50 million gallons. That ethanol would stay in their community. It would boost the number of jobs in their community, and people in the area could buy it, which to me is really attractive. As you know, in Georgia and the Southeast in general, you’ve got a lot of economically depressed areas. It would help the farmers, who are having a heck of a time.
ES: Because of the challenges of distributing ethanol, do you envision a different model than gasoline, perhaps one where there are a large number of small processing plants instead of a small number of large refineries?
Peterson: If you build a four-million-gallon-a-year plant, that production is not really going to make a huge dent in our fuel needs. So it depends on your goal. I firmly believe there’s room for everybody. And we [alternative biomass producers] don’t have to be “instead of corn.” The corn industry in the Midwest has made amazing strides, and they’re continuing to make some improvements. It doesn’t need to be an either-or. Even if we took all the sugar beets or all of the sugarcane and made ethanol from it, that’s not going to be enough to support our energy appetite. We just need to look at what we have a lot of. That perspective is why people come back, especially in Georgia, to the pines. We’re not necessarily using the round wood, board timber, or pulpwood you’d use for paper, but there’s a lot of cellulosic residue out there that we could do something with. I don’t like to see people get into a commodity competition. And I don’t think that’s necessary.
ES: What would you say to critics of ethanol who contend that using corn or other biomass will shrink the supply of food and also drive up prices?
Peterson: There’s always a potential for price fluctuations when you’re using something that has value as food. That’s going to be an issue. But there are all these niche markets that would help agriculture. You can broaden what you’re going to ferment into ethanol to include things that are waste-streamed or residued. Look at the amount of agricultural products left out in the field because they’re damaged, bruised, or infected, or the price is so low farmers can’t really pay to haul it to market. They would get a value for their waste material. We can make ethanol now from trash, residues, and waste products. What we’re trying to do now is make that production cost effective. I think using that feedstock removes that major concern that we’re fermenting something that could be food for someone.
ES: What do you see as the future for ethanol?
Peterson: I see simultaneous development of a lot of different technologies. I’m not sure just ethanol is the answer. I think there need to be lots of answers. We need to become self-sustaining. We need to lessen our dependence on less stable parts of the world. One of the compelling reasons I’m doing this research is for my children. I have young children. I also want to help support the farmers. I want us to be better stewards of the environment. And ethanol is one way to address environmental concerns, as is looking at any kind of alternative energy. We also have to couple that approach with more fuel-efficient cars and tightening our belts.