Processing Pathways

FROM THE AUGUST ISSUE: Interest in cellulosic ethanol from corn fiber is piqued, as technology providers improve on their processes, increasing revenue stream possibilities for producers.
By Lisa Gibson | July 24, 2017

Some producers and technology developers in the ethanol industry say cellulosic ethanol from corn fiber will someday be as commonplace as corn oil extraction—it’ll be a given. The concept has its critics inside and outside the ethanol industry, but a few companies are forging ahead with what they say are revolutionary technologies to make ethanol from corn fiber a reality.

Edeniq, headquartered in Visalia, California, announced in June that it had raised $12 million in the previous year to optimize ethanol production from corn fiber at plants using its in-situ Pathway Technology. It’s the only process on the market that converts corn fiber to ethanol in the existing corn ethanol process, then measures cellulosic versus corn ethanol on the back end to qualify for D3 Renewable Identification Numbers. “Our approach is very simple: You do it through the existing plant,” says Brian Thome, president and CEO of Edeniq. “Through our use of cellulosic enzymes and our ability to measure changes that occur, we can actually tell the plant which gallons coming out of the back end are cellulosic and which ones are not.”

The cellulase enzyme converts the corn kernel fiber into C6 sugars, which are then fermented in the existing process with the starch, Thome explains. It’s a no-capex solution, he says. The only investment is the purchase of the Edeniq enzyme and the D3 registration. “We’re very blessed with a direct advantage over our competitors.” The process saves the upfront investment of millions of dollars worth of bolt-on equipment, he adds.

Pathway is installed at 27 plants, four of which are registered for D3 RINs, seven are in the process of registering, six are collecting information and four have Edeniq on-site for testing. Cam Cast, chief operating officer for Edeniq, says all plants that have filed for D3 registration with Edeniq’s process so far have been approved. The first customer was approved for D3 RINs in September, and Edeniq has gone from “0 to 60” in data collection, fundraising, and now, preparation for process improvements, Thome says. “We now have enough data from all of these plants to be able to go in and look at the cumulative effects—what works best, what doses of enzymes, what operational changes, etc., etc.”

Customers are seeing an average of 1 percent cellulosic ethanol and a 2 percent lift in ethanol production, according to Edeniq. The best-performing plants have seen 2 percent cellulosic ethanol and a 3 percent lift. Thome says Edeniq is continuing to improve its process and 2 percent cellulosic production is a low-hanging fruit. “It is certainly going to be higher than that by the time everybody’s done.”

Jeff Altena, director of operations and controller of Siouxland Energy Cooperative in Sioux Center, Iowa, says Edeniq’s Pathway Technology has yielded 1 percent cellulosic ethanol and a 2 percent lift in production. Siouxland has been using the technology since November and is registered for D3 RINs. “We’ve been researching different methods of adding value for quite some time,” Altena says. “I think every plant in the country does. … You have to look at the technologies that are out there and say, ‘OK. Is this something that will integrate into what we’re already doing, and what’s our end goal?’”

Edeniq was among a few corn-fiber processing technologies Siouxland considered, but it was the only one that guaranteed increased efficiency, Altena says. It also had the lowest price tag, he adds. “It’s done what they told us it was going to do.”

Fiber Separation
A number of other technologies are working their way up to commercial scale in the corn fiber-to-ethanol sector, most boasting a 10 percent increase in ethanol production and all separating the fiber either before or after fermentation.

Fluid Quip Process Technologies in Springfield, Ohio, is adapting wet mill technologies to the dry mill to separate components of the corn kernel, including fiber. The company has technologies that extract the fiber pre- and post-fermentation. Tests show the front-end process yields about 90 gallons of ethanol per ton of fiber, and 85 to 90 gallons for the back-end separation process, according to the company.

The D3Max technology uses the cooked wet cake from the ethanol process as a feedstock. Mark Yancey, chief technology officer, says the demonstration plant at Ace Ethanol in Stanley, Wisconsin, is successful and the company hopes to have its first commercial plant in operation by December 2018.

ICM Inc.’s Gen 1.5 corn fiber-to-ethanol process is prefaced by its selective milling and fiber separation technologies to maximize fiber recovery. The Gen 1.5 design employs front-end separation of fiber. ICM, based in Colwich, Kansas, says it has run multiple 1,000-hour fermentations at full production scale—585,000 gallons.

Meanwhile, Quad County Corn Processors near Galva, Iowa, takes the title of the largest cellulosic ethanol producer under the Renewable Fuel Standard, as well as the first to commercialize ethanol from corn kernel fiber. The plant announced in September 2016 that it had surpassed 5 million gallons.

And on the enzyme and yeast side, Novozymes and DuPont are leading the way, providing updated and optimized organisms. Novozymes announced in June that it added yeast to its bioenergy portfolio. Peter Halling, Novozymes’ vice president of commercial biofuels, says yeast strains in ethanol production have remained largely static, and the company’s new strains will help revolutionize them. Dupont says its corn fiber-to-ethanol enzyme can increase corn oil yield by up to 70 percent, in addition to increasing ethanol production by 10 percent.

In-Situ Vs. Separate Processing
The major differences between in-situ and separate processing are in the cellulosic ethanol lift, the requirements for registration, and cost, says Jim Ramm, director of engineering for EcoEngineers, an Ohio-based clean energy regulation advisory firm. An in-situ process can yield 1 to 3 percent cellulosic ethanol for D3 RINs, versus 7 to 10 percent with separated processing. In-situ also requires recertification annually, or every 500,000 gallons, he says.

But Ramm notes that in-situ does have a low capital cost and is a good way to transition into ethanol production from corn fiber. “It can be a way to get your feet wet in the D3 kernel fiber space without risk.” Producers can coprocess first, establish their marketing methods for D3 kernel fiber and then decide if they want to invest in separate processing to achieve yields of 7 to 10 percent.

Altena says the main draws to Edeniq’s in-situ process are the price, ease of integration into the existing system and flexibility. Because it didn’t change the existing process, it does not eliminate any future options for more efficiency or production, Altena says.

Overall, both pathways show promise, Ramm says. “I think they’re both good methods. Certainly, the economics seem to be there. The potential RIN revenues and energy credit revenues justify both. You can make a return on investment argument for both of them.”

Shifting the Mindset
For an industry producing 15 billion gallons of ethanol, a mere 1 percent increase would yield another 150 million gallons. Bumped up to 2 percent, it reaches 300 million. The value of those gallons, at about $1.50 a piece, and D3 RINs at $2 to $2.30, is “tremendous,” Cast says.

“That shifted mindset is really critical for our industry,” Thome says. “It could happen very quickly. That shift will hopefully help this industry a lot, expanding margins and profitability.”

Cellulosic RINs make up less than 2 percent of total RIN population. Within D3 RINs, cellulosic constitutes 2 percent, the rest being from biogas, Cast cites. “Our goal here, is within the next year, that 50 percent of D3 RINs will be from cellulosic ethanol, due to our technology,” he says.

Thome compares corn fiber ethanol to corn oil extraction at ethanol plants, saying the growth will happen, but the pace is uncertain. Ramm agrees, saying ethanol from corn fiber will be universally accepted. “It’s really the same idea. It’s another feedstock coming in the same bushel of corn, so it’s got a lot of similarities to corn oil.” A policy shift in favor of D3 and a stronger forecast for renewable volume obligations certainly would help the corn fiber-to-ethanol sector grow, Ramm adds.

“We really need to take a leadership position with this,” Thome says of the transition into widespread ethanol production from corn fiber. “There’s a lot to be gained by the industry as a whole and we’re excited to be a part of that.”

Author: Lisa Gibson
Managing Editor, Ethanol Producer Magazine