How Cellulosic is Rising from Corn
The once futuristic vision of integrating traditional and second-generation ethanol facilities appears more attainable as various companies emerge with technology improvements that will allow corn ethanol producers to add cellulosic ethanol streams without taking on insurmountable piles of debt.
Edeniq Inc. was one of the first companies to promote the concept of integrated production. The Visalia, Calif.-based company has been developing technology for that purpose since its inception seven years ago. “That was the purpose of Edeniq—how do you take a process for cellulosic and convert it in a lowest-cost manner and integrate with a corn ethanol plant?” says Brian Thome, Edeniq president and CEO. With help from a $25 million U.S. DOE cost-sharing program, Edeniq has constructed a pilot-scale Corn-to-Cellulose Migration plant in Visalia in order to further perfect the concept. Completion of the plant was celebrated with an official ribbon cutting at the plant to celebrate its completion on June 26, but the facility actually began producing cellulosic ethanol at the end of March. “We like to talk about what we have done rather than what we believe we’ll be able to do in the future,” Thome says. That philosophy could serve Edeniq well as it approaches skeptical corn ethanol producers to discuss migrating toward cellulosic production.
According to Thome, many ethanol producers are quite interested in adding cellulosic to their revenues, but they are cautious about adding risk to a $200 million corn-ethanol plant. “They’re looking for proven technologies,” Thome says. “There are a lot of companies coming into this industry that have not been involved previously that make a lot of promises. As our industry has found out over previous years, those promises don’t always hold water.”
Looking for Leapers
Thome’s company has spoken to many plant leaders who say they want to be the fourth or fifth plant to add cellulosic technology to their process stream, after someone else has taken the leap to be the first to try it. That’s one reason Edeniq recently formed a joint development agreement with Flint Hills Resources Renewables LLC. The Koch Industries subsidiary operates four corn-ethanol plants in Iowa, representing approximately 425 MMgy of production capacity, and has agreed to work with Edeniq to scale up its cellulosic technology.
Flint Hills became an Edeniq investor in May, stating at the time that the investment was part of its strategy to enhance a competitive edge over fellow producers. This could come to fruition quickly, as the first of Edeniq’s three-step migration plan is put into place at one of Flint Hills’ plants. The Cellunator, Edeniq’s particle miller, is used to produce uniformly sized pieces of biomass for conversion to sugars. According to Edeniq, adding the Cellunator to a corn-ethanol plant can increase the facility’s income by $3 million to $6 million annually. Flint Hills also plans to install Edeniq’s corn-oil-extraction technology in at least three of its plants, further boosting their profitability through corn-oil recovery. The ultimate goal will be to test Edeniq’s Pathway enzyme platform, which is designed to allow facilities to produce cellulosic ethanol from corn fiber in the plants’ existing distillers grains. The Pathway enzymes, which will be used in conjunction with reduced amounts of commercially available enzymes, are expected to be ready for use by year’s end. The overall migration process is meant to be gradual, according to Thome, but the technologies allow plants to experience profit improvements along the way. “Our belief is that these plants have the opportunity to incrementally improve their revenues through the addition of technologies such as the Cellunator,” he says.
Thome says Edeniq is certain that corn ethanol producers will be the key to introducing cellulosic ethanol to the market by way of adding cellulosic streams to their existing facilities. “We believe firmly, as do a number of other companies, that we need to utilize the assets that are in the ground and the billions of dollars that have been deployed in our industry, as well as the expertise and operations and knowledge base of the corn ethanol industry, to add cellulosic to existing ethanol plants,” he says. There are challenges, of course, such as feedstock logistics and the formation of inhibitors in the cellulosic process, but Thome says Edeniq is addressing those issues and he believes they can be overcome. “We know, based on everything we’ve done, that you can integrate a portion of cellulosic materials, whether it’s sugar or otherwise, directly into the process and make some changes to fermentation [and] the effluent byproduct usage that are extremely beneficial to the plants and help them increase revenue and drive margins, which they need right now,” he says.
Cutting Costs and Validating
Canada’s largest ethanol producer, GreenField Ethanol Inc., has been developing cellulosic ethanol process technology for half a decade with an eye toward eventually integrating the technology into its four existing corn-ethanol plants. About a year ago, those involved with the technology development project thought they had achieved their goal. The process worked but the problem was it cost too much. “We ended up with an estimated cap ex [capital expenditure] at commercial scale for just the pretreatment package that we knew was not going to work,” says Barry Wortzman, vice president of business development. “Our process was fine and the equipment was executing the process, but the cost to do it was making it noncommercial, so we had to figure out a way to make it less expensive.”
After another year or so of additional development, the company now believes it has solved this problem by developing its own process equipment—a highly modified twin screw extruder that will be used at two places in the biomass pretreatment cycle. Replacing five or six pieces of equipment that would otherwise be required to do the job lowers the capital costs significantly, he says.
The modified extruder is first used at the very beginning of pretreatment. After the feedstock is chopped and sized, it is fed into the extruder, where it is detoxified in preparation for fermentation. At this stage, Wortzman says the extruder replaces two or three other pieces of equipment, and does so without lessening the efficiency of the process. In fact, he believes the extruder is more efficient. Additionally, for feedstocks that require acid treatments, standard equipment would need to be made of expensive, high-grade steel to prevent corrosion. GreenField’s extruder is designed instead with a liner, which again means less capital cost for producers.
The second point the extruder is employed is further downstream in preprocessing, where is it used to wash the material and separate the C5 and C6 sugars for processing. The washing is completed under high pressure using heat, which also contributes to the cooking process, providing a head start on the fermentation. Wortzman says up to three pieces of standard equipment were previously required to complete the washing/separation process that is now handled by a single extruder. “By combining all of this into one piece of equipment, as opposed to three, you have increased the cap ex gains significantly,” he says. “That’s why we believe that what we have got is going to be a real contributor for commercial viability.”
Wortzman declined to elaborate on the financial investment made by Greenfield to develop this technology, but says the company believes it will be worth the expense. “The name of the game is to increase your ethanol throughput in order to meet the demand,” he says, adding that while corn yields may continue to increase, the amount of corn that can be used at ethanol facilities will still be limited. Therefore, it is necessary for producers to incorporate technologies into their facilities that will broaden their range of usable feedstocks. In the case of Greenfield’s technology, that will likely include corn stover and cobs, but the equipment has also been tested on a variety of energy crops and other sources of biomass, including poplar trees.
Greenfield will validate its process on a continuous scale at its Chatham, Ontario, pilot plant later this year. From there, the company plans to roll out the technology at just one of its plants initially and expects to begin constructing its first bolt-on facility in 2014. The company currently operates three facilities in Ontario—an approximately 50 MMgy facility in Chatham, a 60 MMgy plant in Johnstown and a 7 MMgy facility in Tiverton—as well as a 40 MMgy plant in Varennes, Quebec. It’s not yet known which will serve as the inaugural commercial-scale cellulosic site. If all goes well, the cellulosic technology will likely be bolted on to all of Greenfield’s corn ethanol plants, but that decision is not final. “We walk before we run,” Wortzman says. “We have a plan, but we execute it in an incremental way.” Greenfield also plans to market its technology to other producers.
Together but Separate
Other corn ethanol producers and technology developers agree that existing ethanol plants can play a critical role in advancing cellulosic ethanol technology, but they envision co-located, free-standing facilities as the production method of choice. Poet-DSM Advanced Biofuels LLC is expected to be one of the first companies to display this concept. Its 20 MMgy corn cob-to-ethanol facility in Emmetsberg, Iowa, is currently being constructed adjacent to Poet’s 55 MMgy corn ethanol facility and is on pace to be operational in 2013. As the largest ethanol producer in the U.S., Poet has a wealth of corn ethanol production knowledge, and it’s that knowledge base that attracted DSM to the project as it sought a partner to demonstrate its sugar conversion technology. “DSM is the only company that can simultaneously ferment all C5 and C6 sugars in cellulosic biomass,” says Joost Dubois, branding director for bio-based products and services at DSM. “Furthermore, we have a proven track record in scaling up and running industrial biotech and large chemical operations that we will combine with Poet’s strength in process technology and infrastructure.” Dubois says that DSM wasn’t looking specifically for a co-location project to mark its entry into the U.S. cellulosic ethanol industry, but the strategy does offer clear advantages to the production process. “The Emmetsberg facility has a full infrastructure of [feedstock] suppliers and Poet has invested several years in building up experience in the collection of biomass on-site,” he says. “It is clear that co-location brings multiple advantages from a cost, staffing, biomass and logistics point of view, so the economics are clearly more favorable for a co-located plant than a stand-alone.”
Meanwhile, Denmark’s Inbicon has also based its cellulosic ethanol technology strategy on co-locating second-generation facilities with existing ethanol plants. Paul Kamp, director of sales and project development for Inbicon, says corn ethanol producers can reap a multitude of benefits through co-location, including increased profits and reduced energy costs. It’s possible that by utilizing energy produced through the cellulosic plant’s process, a traditional ethanol plant could also lower its carbon intensity to the point of qualifying the traditional fuel as an advanced biofuel, thus increasing demand for that product as obligated parties seek out advanced fuels to meet renewable fuel standard requirements. The build-out has been slow to start, but if the biofuels industry is going to meet the renewable fuel standard’s 36 billion gallon volume requirement in 2022, Kamp believes the industry needs to get back on track and begin rapidly expanding capacity. The corn ethanol industry has done it once before, and Kamp and others believe they can, and must, do it again.
Author: Kris Bevill
News Editor, Ethanol Producer Magazine