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Why Cellulosic Ethanol Depends on a Renewable Fuel Standard

Words by RP Siegel

As part of our series on biofuels, I recently spoke with Adam Monroe, President of Novozymes North America. I called to talk abut the Renewable Fuel Standard (RFS), but like all good conversations, ours wandered beyond the original topic and into a discussion about cellulosic ethanol, the development of which, as it turns out, depends heavily on continued support of the RFS.

Triple Pundit:You’re in Europe right now. What is the perspective over there on biofuels? Most of what we hear about is what is happening here in the U.S.

Adam Monroe: There is definitely interest all around the world. The Europeans, I would say, are coming at this more from a climate change perspective. They are looking at the RFS and wondering if that could be a policy for them. There is quite a bit of innovation going on in this space. Italians are coming online with one of the largest cellulosic plants in the world using wheat straw and subsequently energy cane. It’s going to take a little while for them to sort through what’s best from a policy perspective.

3p: So this is still pretty much in the future for them?

AM: Well not from a production standpoint. There is a good amount of production going on in Denmark. You’ve got Italy and Spain. They are creating a first wave of commercialization. And they are exporting those models around the world.

3p: What feedstocks are they using?

AM: Everything from wheat straw to grain based, to energy grass, arundo donax, which is prevalent in Italy, along with wheat. The Spanish also use corn and I believe they’re also looking at corn stover

3p: If you look at where we today relative to the RFS, it says that by the year 2022, a total of 21 billion gallons of biofuel needs to be provided by something other than corn. That puts a lot of burden on the cellulosic side. There’s going to have to be a lot of movement if you’re going to make that goal.

AM: That’s exactly right. I’ve gotten that question a lot about why are we behind. If you look at the biomass resources in the U.S., there’s over 60 billion gallons that can be made just from the sustainable biomass resources. Just ag[ricultural] residue alone, taking in just 17 percent of this residue, which is well under the amount that’s considered sustainable, that’s 16 billion gallons right there. So the 21 billion number is, in many ways, a conservative number. But there are a number of things that people don’t see, like this fantastic wave of innovation that has made possible other feedstock options, new pathways to get to cellulosic. That’s a lot for the EPA to consider. This wave of innovation has overwhelmed the agencies. So, from my perspective, for a brand new industry, just launched in 2007 and we’re on the cusp of commercialization - that’s pretty impressive if you ask me.

3p: What is the main thing driving this move towards cellulosics?

AM: Well, let’s just call it like it is. The RFS is absolutely the linchpin policy. If we didn’t have the Renewable Fuel Standard, I would have a very difficult time predicting when you’d have this transformation. That’s because you’re trying to break into a very large, highly developed industry, with tons and tons of infrastructure that has a lot of capital invested in it. So to get in there and have a level playing field to allow the public to have a choice of fuels, the Renewable Fuel Standard is absolutely key. Having said that, there is a very serious realization that we need renewable carbon. I mean carbon is in every form of life from our food, to our materials, to our energy and we have to get to renewable sources of it. The only way to get to that is to take it out of the atmosphere and recycle it. So it becomes very obvious when you look out into the future and consider the pressure that’s going to be placed on fossil energy and everything that comes with it, renewable carbon is the way to go, and cellulosic renewable carbon is the largest source. I think that the innovation that the RFS stirred, has really given everybody a new set of binoculars as to the possibilities that are out there for making the molecules that we know today.

3p: The question of cellulosic vs. starch-based ethanol runs across a number of issues, such as food vs. fuel. Is there a perception out there that perhaps the cellulosic approach that uses byproducts, rather than primary agriculture, is somehow more sustainable?

AM: I think it falls into two camps. I think there’s one camp that is convinced that the food side of this is a much bigger deal than it is, therefore anything other than that is a better choice. Then there is the other side that says, well, look at all the biomass and carbon that’s available that’s not in a grain form that we can get at and couldn’t that be exciting. Wouldn’t that be a huge resource for the world if we can learn to convert it into the things we need?

3p: What about if you take the corn and remove the starch for ethanol and you set aside the protein for animal feed, then using the rest of  plant to make cellulosic ethanol; is that being done?

AM: Yes, in fact, one of the synergistic models that are out there is being pursued by companies like Abengoa, Poet, ICM and DuPont. When you are harvesting the kernels from the corn, you also harvest what works out to the top third of the plant. That’s a lot of biomass and it’s some of the easiest to convert into a sugar. Then you send the sugar stream to the same ethanol producer. What’s neat about that is that the part that’s not converted, that’s the lignin. The lignin has a very high energy value. And that can be used within the facility for heat. So when you combine that energy into the ethanol facility you get some very high synergies there. That helps to lower the energy cost overall. It helps to produce more ethanol from the same land and it has an even better greenhouse gas impact.

3p: Clearly, by combining the two, you’re getting far more energy out of the same amount of land and water. Do you have any idea what the combined yield would be in gallons per acre?

AM: Of course it depends on a number of factors, but according to our calculations you get an additional 19 percent above and beyond what we get today from the kernels.

3p: That’s great. So ideally, you would have a corn processing facility that is capable of producing ethanol from the corn kernels, or from the stover, and creating animal feed, or corn syrup, almost like a flexible manufacturing kind of arrangement. Is that kind of thing happening now?

AM: That’s what you’re starting to see happen in Europe. The technology that has been developed to extract all the nutrients and all the energy and the fiber and everything else that we can from renewable sources of carbon is going to be really important. All the technology and the work that we do on the non-starch-based side is the new wave and it is something that has tremendous potential that’s commercializing now. So we just need to hold our course and I think we’re going to be able to look back in five to ten years and see a huge industry out there that’s employing lots of people, both in the United States and globally.

3p: Looking at this from the sustainability perspective and I see a lot of potential here in extracting value from what was previously considered waste. Both in the sense that Craig Stuart Paul was talking about with municipal waste, and what we’re talking about here with agricultural crop residues. I can envision a plant in a corn-growing region that has the ability to use the various inputs, the kernels, the cobs, the leaves, etc. and use them to make starch-based biofuel and cellulosic ethanol and animal feed, and whatever else, all under one roof, using the entire plant like the Indians once did with the buffalo.

AM: I think you just described the refinery of the future. They’re not all going to be in the Corn Belt either. They are the Fiberights, making ethanol from municipal waste, and wood chips and everything else from the Northwest, to Southern pine pulpwood that right now has no place to go, and energy grasses in places where we are not able to grow anything else. It’s all going to be very exciting as long as we can hang on to the policy that got us there.

[Image credit: morgan.burke2: Flickr Creative Commons]

RP Siegel, PE, is an inventor, consultant and author. He co-wrote the eco-thriller Vapor Trails, the first in a series covering the human side of various sustainability issues including energy, food, and water in an exciting and entertaining format. Now available on Kindle.

RP Siegel headshotRP Siegel

RP Siegel (1952-2021), was an author and inventor who shined a powerful light on numerous environmental and technological topics. His work appeared in TriplePundit, GreenBiz, Justmeans, CSRWire, Sustainable Brands, Grist, Strategy+Business, Mechanical Engineering,  Design News, PolicyInnovations, Social Earth, Environmental Science, 3BL Media, ThomasNet, Huffington Post, Eniday, and engineering.com among others . He was the co-author, with Roger Saillant, of Vapor Trails, an adventure novel that shows climate change from a human perspective. RP was a professional engineer - a prolific inventor with 53 patents and President of Rain Mountain LLC a an independent product development group. RP was the winner of the 2015 Abu Dhabi Sustainability Week blogging competition. RP passed away on September 30, 2021. We here at TriplePundit will always be grateful for his insight, wit and hard work.


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