EPA: Cellulosic ethanol from corn residue is carbon negative

There has been a lot of talk about the final rule on the Renewable Fuel Standard (RFS2) released recently by the U.S. EPA (funny how 3,000 pages will do that). Most of that talk has centered on what the rules mean for the existing corn ethanol, which the EPA determined meets the threshold of emitting at least 20 percent fewer greenhouse gas emissions than gasoline.

But what hasn't generated nearly as much discussion is what the document had to say about cellulosic ethanol. The cellulosic biofuel requirement in RFS2 is 16 billion gallons by 2022. The law had called for 100 million gallons this year, but the EPA reduced it to 6.5 million due to a projected production shortfall.

In their analysis of cellulosic ethanol made from crop residues such as corn stover using a biochemical process like we're employing for Project LIBERTY, the greenhouse gas (GHG) reduction is 130 percent in comparison to gasoline. In other words, driving your car with POET's cellulosic ethanol actually takes carbon out of the atmosphere.

For this reason and because of the availability of agricultural residue, the EPA expects it, and especially corn stover, to be the feedstock that contributes the most cellulosic ethanol toward meeting the 36 billion gallon target. On page 184 of the preamble, they state:

Agricultural residues are expected to play an important role early on in the development of the cellulosic ethanol industry due to the fact that they are already being grown...The most common residues are corn stover (the stalks, leaves, and/or cobs) and straw from wheat, rice, barley, and oats. These U.S. crops and others produce more than 500 million tons of residues each year, although only a fraction can be used for fuel and/or energy production due to sustainability and conservation constraints. Crop residues can be found all over the United States, but are primarily concentrated in the Midwest since corn stover accounts for half of all available agricultural residues.

The EPA sites one recent study showing that "under current rotation and tillage practices, about 30 percent of corn stover produced in the U.S. could be collected, taking into consideration erosion, soil moisture concerns and nutrient replacement costs." The ultimate amount removable by the farmer will of course vary by geographic location, soil quality and tillage practice, the EPA noted.

The EPA goes on to say: "Our agricultural modeling suggests that corn stover will make up the majority of agricultural residues used by 2022 to meet the EISA cellulosic biofuel standard (4.9 ethanol-equivalent Bgal)." Although we're only producing small amounts of cellulosic ethanol now, POET would like to be a big part of that big goal.

Answering public questions about corn cobs, POET's cellulosic ethanol costs

POET’s announcement last week that we’ve lowered the cost of producing cellulosic ethanol from $4.13 down to $2.35 got noticed by media outlets and blogs across the country.

Coverage from national mainstream media outlets included the Washington Post, the Associated Press, Clean Skies TV, and many more. Some notable blogs in the energy and alternative energy sphere also addressed the issue, including R-Squared Energy Blog, Green Car Congress, Salon.com, Climate Progress and Daily Tech.

The blogs were especially interesting because we could gain some insight into the public’s thoughts about what POET is doing thanks to the blog posts and comments from readers. A few issues came up repeatedly, and I’d like to address them here:

 

Q.    Does the cost include factors such as depreciation, labor, insurance, etc?

A.    Yes. We’ve been making ethanol for more than two decades, so we’ve got a pretty good sense of how to figure the cost of production at an ethanol plant. All commercial factors were included in our final number.

Q.  Does the cost incorporate the benefits of tax credits or other government incentives?

A.  No, the $2.35 figure represents the cost without any financial assistance.

 

Q.  Will removing corn cobs damage the soil?

A.  POET is funding research through Iowa State University to gather additional information on this important issue, but a number of studies have already been done on this subject, and they all indicate that taking corn cobs will not make a significant difference in soil nutrient content.

 

For instance, an April, 2009 study by Canadian researchers published in the Agronomy Journal concluded that “The potential therefore exists to use crop residues for ethanol production or other industrial purposes without adversely affecting the long-term productivity of medium- to heavy-textured soils providing that <40% of the total above ground residues other than grain are removed and the frequency of removal is no more than 2 yr out of three.”

 

Previous research from Iowa State (before POET was involved) has shown that the corn cob represents 5-7 percent of the nutrients (Nitrogen, Phosphorus, Potassium) in the stover.  To be clear, that does not include the grain. This is consistent with other research we've seen.

 

There has been enough research done to move forward confidently in this project, however we continue to seek more information so we can help farmers find the best way to manage their land while providing cobs for cellulosic ethanol production.

 

Q.  What are POET’s assumptions for the cost of purchasing cobs, and will farmers bring cobs in for that price?

A.  POET figures the cost of cobs at $55/ton. We figure the average farmer stands to gain a profit of about $20 per acre based on this cost, which includes equipment, labor and other costs. In addition to that, the Biomass Crop Assistance Program will provide farmers up to an additional $45/ton in matching funds for two years to help defray startup costs for farmers entering the biomass market.

We've had a great reaction from farmers in the Emmetsburg, Iowa area, and we're confident that others will have a similar reaction once they learn the details. POET Biomass, a new division at POET, helps farmers tailor their cob harvesting plans to best fit the needs of each particular farm.

Biofuel feedstocks of the future

Last week, I visited the Region 7 office of the U.S. Environmental Protection Agency to participate in a panel discussion about the feedstocks that will be used for biofuel production in the future. The panel discussion was part of the Ag Week conference put on by the EPA Region 7 Ag Team. I was joined on the panel by Dr. Emily Heaton from Iowa State University, Alan Weber from the National Biodiesel Board and Greg Karr of the Midwest Research Institute.

POET was invited to talk about our progress toward producing cellulosic ethanol from corn cobs. Here's the presentation I gave. After it loads (which may take a while) just click on it to advance the slides:

More research reaffirms the use of crop residue for cellulosic ethanol

A group of Canadian researchers published a paper in the Agronomy Journal seeking to quantify the amount of crop residue that can be used for ethanol production without adversely impacting soil quality. They conducted two studies:

1. The first evaluated three harvesting systems and their impact on straw removal with baling
2. The second measured straw removal after 50 yr on soil quality and wheat production using a fallow-spring wheat-spring wheat rotation (F-W-W) with three different treatments imposed

Their conclusion: Measurements of soil organic carbon and nitrogen showed no differences after 50 yr of straw removal, and spring wheat grain yields and grain protein concentration were also not affected based on the second study. The potential therefore exists to use crop residues for ethanol production or other industrial purposes without adversely affecting the long-term productivity of medium- to heavy-textured soils providing that 40% of the total above ground residues other than grain are removed and the frequency of removal is no more than 2 yr out of three.

These findings are similar to other studies we've seen, some of which have shown that as much as 50 percent of the stover can be removed without negatively impacting soil quality. As mentioned in the prior post, POET is working with Iowa State University to study the impact to the soil of using corn cobs for ethanol production and thus far research has shown that it has little to no impact. This is something we will continue to monitor closely and the Agronomy Journal provided an important contribution.

Cob Removal Treads Lightly on Soil

As stated in my last post, the U.S. Environmental Protection Agency’s Draft Regulatory Impact Analysis stated that corn stover is the most economical agricultural feedstock to be used to produce ethanol. Apparently, Iowa State University would agree.

New ISU research shows that using corn cobs for cellulosic ethanol will not harm soil nutrient content. The research was funded by POET as part of our ongoing internal study into the sustainability of using corn cobs as a feedstock for next-generation ethanol. According to the study, conducted on a test field near the Emmetsburg site, fertilizer treatment for a field in which cobs have been removed would be identical to treatment of a field in which cobs were not removed. ISU researchers will continue their work this year on the test plots, compiling more data to help farmers manage their land well while taking advantage of an additional revenue source from their fields.

Previous research by the U.S. Department of Agriculture showed that cobs contain only 2-3 percent of the measured nutrients of the above-ground corn plant. This has been confirmed by previous ISU research.

The new ISU research takes a closer look at data regarding soil quality and nutrient levels, the impact of cob and stover removal on future plant growth, and recommended levels of fertilizer applications, if any, for cob or stover removal. Once again, research seems to conclude that using corn cobs for ethanol makes sense economically and environmentally.

National Commitment to Cellulosic Ethanol

This was a monumental month for Project LIBERTY and all our partners as we move forward in changing the nation's energy landscape. On May 5, President Barack Obama issued a presidential directive creating a biofuels working group in his cabinet and the U.S. EPA issued preliminary rules for the Renewable Fuel Standard.

The President's actions reinforce his full-fledged support for cellulosic ethanol with an ambitious plan to boost investment in commercial projects to hasten the nation's transition to renewable fuel. Nearly $800 million form the American Recovery and Reinvestment Act will be used to accelerate biofuels research and commercialization, Secretary of Energy Chu announced. That money will be used to reinvest in both new and existing demonstration and commercial biorefineries, boost research efforts in next-generation biofuels, upgrade infrastructure to expand the availability and use of E85 and more. Click here for a statement from POET CEO Jeff Broin.

But clearly, a key feature was a finding by the EPA's Draft Regulatory Impact Analysis (pdf), "...Corn stover was chosen as the most economical agricultural feedstock to be used to produce ethanol in order to meet the 16 billion gallon EISA (Energy Independence & Security Act) cellulosic biofuel requirement." The EPA went on to say, "We estimate that by 2022 greater than 400 million tons of corn stover could be produced. Approximately 82 million tons would be needed to produce 7.8 billion gallons of cellulosic biofuel that our modeling projects to come from corn stover by 2022." Using corn cobs for ethanol makes sense economically and environmentally.

POET's use of corn cobs is a clear winner in the EPA's analysis of future cellulosic ethanol production. This puts Project LIBERTY and Emmetsburg-area farmers at the forefront of the nation's energy future.

IFT: corn cobs are the "low-hanging fruit" for cellulosic ethanol

The cover story of the August 23 issue of Iowa Farmer Today (IFT) sounds ominous: Harvest Quandry: Stover as biofuel raises new questions. The article from Gene Lucht talks about the importance of considering soil quality when evaluating corn stover as a feedstock for cellulosic ethanol.

But when you follow the article inside the publication, you find this paragraph:

Of course, there are areas where the industry could turn as it continues to explore the stover possibilities. One logical way of harvesting some biomass while not affecting soil quality and erosion heavily would be to harvest the cobs.

“It’s the low-hanging fruit,” Johnson says. (Jane Johnson is a research soil scientist with USDA-ARS at the North Central Conservation Research Laboratory in Morris, Minn.)

While the article states that cobs make sense from an agronomic perspective, Purdue University says they also make sense from an economic perspective. We covered that story on Rhapsody in Green. These are a few of the many reasons why POET believes that corn cobs will provide the fastest route to commercialization of cellulosic ethanol. IFT is on top of that in their sidebar: Corn cob ethanol production near.