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By Robert Rapier on Jun 17, 2009 with no responses

POET Sets the Standard

In a recent post (but certainly not the first time I mentioned this), I wrote:

Corn ethanol producers have to move away from fossil fuel inputs – or they need to otherwise find inputs that don’t normally track gasoline prices. This is why the sugarcane ethanol producer can compete on a level playing field with gasoline. The fertilizer inputs for sugarcane are much lower than for corn, and the distillation energy is provided by biomass. The only way the ethanol industry in the U.S. will be able to break free from the subsidies is to adopt similar practices.

The ethanol company POET, which I recently described as setting the standard for ethanol production in the U.S., has just taken a big step in that direction. This press release was just e-mailed to me:

Waste material to power cellulosic/grain ethanol plant

POET installs anaerobic digester at pilot cellulosic ethanol facility

SIOUX FALLS, S.D. (June 17, 2009) – A self-sustaining energy cycle for producing cellulosic ethanol is close to reality with the recent startup of an anaerobic digester at POET’s pilot plant in Scotland, S.D.

Corn cobs at Project LIBERTY will not only be used to produce ethanol; the liquid waste will go to an anaerobic digester to power the cellulosic plant and offset natural gas usage at the attached grain ethanol plant as well. That’s renewable energy created at the plant, powering the plant and powering the adjacent facility.

POET installed and fired up its anaerobic digester, which was designed and built by Biothane, on May 20. The digester uses liquid waste created in the process of converting corn cobs to ethanol. That waste is used to produce methane gas, which acts as roughly the equivalent of natural gas.

“This technology will cut fossil fuels out of our cellulosic ethanol production process and further improve the benefits of grain-based ethanol,” POET CEO Jeff Broin said. “Over the long term, POET would like to eliminate the use of fossil fuels at all of our plants through a variety of alternative energy sources.” The alternative energy technologies employed at other POET facilities include a solid waste fuel boiler, landfill gas and cogeneration.

The digester is in the research phase – corn cobs have never been used in this way before. The methane is currently being flared, but once the process is refined, it will be installed as part of Project LIBERTY.

Project LIBERTY is a 25 million gallon-per-year cellulosic ethanol plant, which will be built in Emmetsburg, Iowa. Research and development work is on schedule for the plant to begin production in 2011.

A photo of the anaerobic digester is available at

To see a documentary about POET’s pilot cellulosic ethanol plant visit Media outlets are welcome to link to the documentary in online coverage. Photos are also available for publication at

About POET

POET, the largest ethanol producer in the world, is a leader in biorefining through its efficient, vertically integrated approach to production. The 20-year-old company produces more than 1.54 billion gallons of ethanol annually from 26 production facilities nationwide. POET recently started up a pilot-scale cellulosic ethanol plant, which uses corn cobs as feedstock, and will commercialize the process in 2011. For more information, visit

What POET is doing is similar in spirit to what E3 Biofuels attempted. E3 had some startup problems that ultimately put them out of business, but as I described it at the time, this is I believe a necessary step for the ethanol industry. While I don’t expect this approach to be as cheap as using natural gas or coal for power, in the long run using biomass to power their plant will dampen some of the oscillations caused by volatile fossil fuel prices.

One other key issue – and I have seen conflicting information on this – is how much biomass can be removed in a sustainable manner. Since POET is just using cobs, they are probably OK. Start taking out large amounts of stover, and you may run into trouble. But using cobs solves many of the logistical challenges that cellulosic ethanol in general will face. The cob is already being collected with the corn (analogous to bagasse) so a portion of that logistics battle is already included in the deal. This is also why I think lignocellulose to fuel schemes need to focus on biomass already coming into central locations, such as landfills.

The one other obvious question is just how much natural gas can be displaced by digesting the liquid waste. Since they are still in a research phase, they probably don’t even have a good answer to this yet.