As Gevo recommences the switchover to bio-based isobutanol at its first commercial plant, we look in-depth at 2012′s contamination issues and the prospects and path forward.
In Colorado, Gevo, Inc. (NASD:GEVO) announced that it has resumed commercial production of isobutanol at its Luverne, Minn. plant in single train mode, successfully utilizing its proprietary Gevo Integrated Fermentation Technology (GIFT).
“I am pleased to report that we have been successful in operating our full scale fermentation and our GIFT separation system that separates the isobutanol from the fermentation broth. This serves to further validate our technology as we had not previously run the GIFT system at full scale. I can now say that it runs beautifully,” noted Gevo CEO Patrick Gruber.
“We plan to be producing isobutanol and operating throughout the rest of this year, bringing all of our fermenters and GIFT systems online in the third and fourth quarters, testing run rates, then ramping up production and sales in 2013 and 2014” Gruber added.
“We will sell the isobutanol we produce, using it for market development in the specialty chemicals market, in specialty oxygenated fuel blendstocks markets, and as a building block to make fuel products such as jet fuel and chemical products such as paraxylene for polyester used in the production of bottles and fibers.” Isobutanol applications for the specialty chemicals and chemical intermediates sectors include work in paraxylene with Toray (OTC:TRYIF) and Coca-Cola (NYSE:KO).
Let’s look at the 2012 problem – what it was, what it wasn’t. At the end of the day, the problem at Luverne came down to this guy and friends of his strains of bacillus, a rod-shaped, single-celled bacteria with an insatiable appetite for dextrose, or corn sugars.
Microbial infections are a common feature of world-scale fermentation especially in their commissioning period they’re a common nuisance with ethanol plants, also, that have developed antibiotics and other strategies to combat them.
As Gevo CEO Pat Gruber observed, in talking with the Digest, “First step was, for us, to make sure we understood all the competitors that are chewing up the sugar, eating up yield. There’s no way to know until you do it, at scale. What matters is how you respond.”
Bacteria lurk. Picture the small white infection spots you see on a child’s inflamed tonsil when tonsillitis or strep throat strikes and parents will know that those type of infections can go away and then suddenly strike again. Those are lurking bacteria that have found a happy home, hung up in a tube somewhere inside the body lying in wait for the right conditions to appear, and then spring back into view.
It is not completely different with microbial contamination in fermentation systems likewise, the microbes embed themselves in small infection pockets, and then rise up in numbers when the sugars start to flow.
“You are always going to have microbes, whether they come in through the air or water,” said Gruber. “But there is manageable, and then there is outnumbered
In Gevo’s case given that this is a new system, producing isobutanol instead of ethanol, it was essential to understand the particular cocktail of microbes before designing a remedy. “The fixes included changing the fermentation conditions and related operating parameters,” noted Gruber, “making equipment modifications to improve sanitization, and, most importantly, improving our operating disciplinethe procedures we use at the plant.
The House that
Ruth Gevo Built
Let’s visit one aspect of Gevo’s changes for a moment. Interestingly, the production yeast microbe itself has not been altered. But the fermentation conditions were changes to ensure that it competes more effectively with whatever other critters get into the soup.
In its own way, not entirely unlike the way that the original (1923) Yankee Stadium, “the House that Ruth Built,” was designed with the Bambino’s batting style in mind. That facility had the “short porch” in right field tailored to Ruth’s left-handed pull swing, leaving big hitters from visiting teams to face 450-foot stretch of center field known as “Death Valley”.
The drought and the corn crisis
The path forward from 2012′s microbial infections might have looked differently if corn prices had not soared following the 2012 drought. The original backup plan for Luverne in the commissioning phase was to return to ethanol production, or to continue to produce isobutanol and work through yield and process improvement. But, as Gruber noted to the Digest, “it’s one thing if corn is $4 or $5. With corn at $7.50 and going to $8, profitable ethanol production was essentially out of the question,” so we decided to pause production last fall after generating the isobutanol we needed for initial market development.
The path to full production
“For now,” Gruber notes, “we are currently operating in single train mode. It is easier to manage one fermenter and one GIFT separation system while we learn how to run the plant at full scale. Also, it is a more efficient use of corn feedstock and we gain valuable operating experience as we go.”
Having said that, one fermenter at Gevo scale is, ahem, not exactly nothing given that they are operating at million liter scale.
Let’s put that in the context of some other highly-successful paths to scale. Genomatica is operating at around 600,000 liter scale, Solazyme (SZYM) has reached 500,000 liter-scale, and we understand that Amyris (AMRS) is operating at something around 200,000 liter scale at the moment. Each company will find the scale that is right for their process it is not the case that 500,000 is inevitably better than 200,000 although economies of scale apply.
The point is, operating in single-train mode with a million liter fermenter is akin to operating two at Solazyme scale, or more at Amyris scale.
The expectation is that Gevo will have all of its fermentation units running at scale by year end, and the company continues to aim towards its critical delivery dates in 2015 for its clients.
Redfield, Biofuel Energy and other projects
What about expansion of the Gevo system to Redfield and other plants, such as Biofuel Energy? “too early to say on timeline,” Gruber told the Digest. “The interest is out there. But for now we are going to be fully focused on getting the production optimized at Luverne.”
What about cellulosic sugars? For sure, Gevo has noted that companies like Sweetwater are landing deals with ethanol plants to bring cellulosic sugars into their production streams. “We can work with cellulosic sugars, for sure” said Gruber, “but our cellulosic is not ready for prime time.”
The Gevo-Butamax dispute
Next stop in the never ending battle between Gevo and Butamax over their respective patents is an August trial date over the ’375 Gevo patent, relating back to the use of a specific gene that has been knocked out to ensure high production rates for isobutanol. This is a Gevo suit against Butamax there remains pending litigation on appeal relating to Butamax suits against Gevo for infringement on Butamax patents.
And the eff
orts to invalidate each others patents go on, as well. And on. And on.
The Bottom Line
It’s good news across the industry that Gevo is back to isobutanol production and there are no voices amongst the Digesterati indicating that a slow-and-steady approach to having all the fermenters online before year end is a bad idea.
Items to watch? The August trial on Gevo’s patents. Corn prices, generally. A steady progress between now and end-of-year to having all the fermenters online. For the longer term, announcements on the Redfield second commercial facility, and progress with cellulosic sugars.
Jim Lane is editor and publisher of Biofuels Digest where this article was originally published. Biofuels Digest is the most widely read Biofuels daily read by 14,000+ organizations. Subscribe here.