Ending the Enzyme Enigma

Figuring out how to produce enzymes at a feasible cost is just part of the puzzle
By Kris Bevill | May 13, 2011

A decade ago, the cost of enzymes was at the top of the list of concerns for most would-be cellulosic ethanol producers. With some estimates placing them at around $5 per gallon of ethanol produced, enzyme costs were higher than the cost of feedstock in some cases, making cost-effective production nearly impossible to achieve. But after hundreds of millions of dollars spent on collaborative research and development efforts that crisscrossed the globe, enzyme costs have been dramatically reduced and are now being proven for commercial-scale use. There is still work to be done, but developers say they are continuously improving their enzyme systems and, with the help of producers, are ready to launch the cellulosic ethanol industry into full-speed commercialization mode.

‘Sea of Change’
“We think this is a year that is quite pivotal for the industry because we will see groundbreakings for commercial plants,” says Cynthia Bryant, global business development manager of bioenergy for Novozymes. “I’m hoping this is going to be the sea of change shift that we need in order for people to finally agree and see that the technology is no longer two or three years out. It is available. It’s here today. It actually has been here for awhile.”

Novozymes has been working for years to develop cost-effective enzymes for the ethanol industry. Its most recent development in this arena has been its trademarked Cellic CTec 2 enzymes, which Bryant says is the result of a goal set by the company’s CEO in 2008. Steen Riisgaard declared then that the company would deliver commercially viable enzymes to the cellulosic ethanol industry by 2010. Last February, the company unveiled Cellic CTec 2, which Bryant says enables producers to reduce enzyme dosage requirements and improve performance by 1.8 times on average, regardless of feedstock. The product will soon be put to the test in a real-world, commercial-scale scenario. Italy-based chemicals and plastics firm Mossi & Ghisolfi Group has been collaborating with Novozymes for a few years and recently broke ground on a 13 MMgy wheat straw/Arundo donax-to-ethanol facility in northwestern Italy. The project, expected to be the largest cellulosic plant in the world, is scheduled to begin production, using Cellic CTec 2 enzymes, next year.

Genencor, a division of Danisco, has been investing heavily in cellulosic ethanol enzyme development since 2000, according to the company’s business development director, Aaron Kelley, and has been aggressively launching new enzyme packages for the industry since 2007 when it introduced its Accellerase line of cellulose enzymes. “That was an interesting internal decision for us, because we knew at that time there wasn’t a significant market and we weren’t going to sell a lot of the product,” Kelley says. “But we felt it was important to start the conversation.”

Genencor’s most recent improvement, DUET, was also introduced last year. The product offers an improvement on hemicellulase, which also improves the digestibility of C6 sugars. Kelley says the overall result for users is a three-fold reduction in enzyme requirements. Genencor is also expected to soon have a commercial-scale home for its cellulosic ethanol enzymes. Dupont Danisco Cellulosic Ethanol LLC is scheduled to break ground on its 25 MMgy corn stover-fed facility, dubbed Project Blackhawk, in Iowa this summer. The plant will use a Genencor enzyme system tailored to suit that specific facility, so Kelley says it will serve as a good showcase for Genencor’s technology, but won’t be used as an indicator of all the company has to offer.

Progress on All Fronts
Novozymes and Genencor may control the lion’s share of the enzyme manufacturing industry, but several smaller players appear to be making their own headway in producing enzymes for the cellulosic ethanol industry. Verenium Corp., which was initially an enzyme developer, famously ventured into the production side of cellulosic ethanol a few years ago with its demonstration-scale facility in Jennings, La. Its partner for the project, BP, has since acquired all of the production-related activities and Verenium continues its research and development of enzymes for cellulosic ethanol production. Royal DSM, a Netherlands-based life sciences and materials company is also involved in a multiyear enzyme development project for the cellulosic ethanol industry.

Mark Emalfarb, president and CEO of Florida-based Dyadic International, believes smaller firms like his offer a unique ability to service the cellulosic ethanol industry. His company has been developing enzymes to produce sugars from biomass for years and he says that because his company is smaller than some of the other enzyme developers, (it has about 18 people on its research team) it is more able to adapt and as a result has created “a better mousetrap” than the large firms. Dyadic’s most notable collaborator to date is Abengoa Bioenergy, which acquired a stake in Dyadic in 2007 and signed a license agreement with the company in 2009, giving Abengoa the rights to continue developing the enzyme technology.

Gerson Santos, corporate director for Abengoa Bioenergy New Technologies, says Abengoa’s fully staffed research and development lab in Spain is currently optimizing the technology that will be used for its enzymatic hydrolysis process. The company had a significant breakthrough last summer when it began using its enzymes in Abengoa’s demonstration-scale facility in Salamanca, Spain. “This was a success and we are meeting our goals,” he says.

Abengoa plans to break ground on its 25 MMgy corn stover/wheat straw-to-ethanol plant in Hugoton, Kansas, this summer. The facility will utilize the enzyme technology being developed in Spain and Santos is confident that enzymes will be a non-issue for the facility. “Our enzyme system will be ready when the plant is ready, there is no doubt about it,” he says.

At What Cost?
As mentioned, the cost to use cellulosic ethanol enzymes has been a major factor thus far in the development of a commercial-scale cellulosic ethanol industry. Developing the enzyme systems has not been exactly cheap either, to put it mildly. Genencor alone has invested more than $100 million in its development projects. Emalfarb says his company has raised $70 million since going public. The U.S. federal government is also heavily invested in this arena. Andy Aden, a senior research engineer at the U.S. DOE’s National Renewable Energy Laboratory says the DOE has invested more than $1 billion in more than 20 integrated biorefinery projects in the past decade and has provided multiple grants to many of the enzyme manufacturers. This combined effort has garnered tangible results. Aden says the most common price range for cellulosic ethanol enzymes has dropped from $5 per gallon 10 years ago to between 50 cents and $1 per gallon today. “If it is that range, yes it’s still an important cost component, but it’s not the overall hurdle it once was,” he says.

Aden is part of an NREL team that is auditing and validating the enzyme development work of four manufacturing firms—Novozymes, Genencor, Verenium and DSM—as part of a project funded by the DOE’s Energy Efficiency and Renewable Energy Biomass Program. The program has provided the companies with a total of $1.3 million since 2007 for research to improve the activity and production efficiency of enzymes. The original funding announcement cited an objective of achieving an enzyme cost of 12 cents per gallon by 2011 and having requisite quantities of enzymes available for pilot testing by 2012. Because the final evaluation of the projects is currently being conducted, Aden wasn’t able to share early results, but he says he’s not sure the original price target per gallon is still applicable. The project is scheduled to end next September.

Abengoa has pegged a goal of 40 cents per gallon for its enzyme system input costs. “That’s in line with what our competitors are doing and right now we believe that is achievable based on the progress we’ve been making and on the progress others have made as well,” Santos says. “I’m fairly confident we will be achieving that objective.”

Collaborative Efforts
Kelley says that while enzyme costs are still significant, focusing only on the cost per gallon of enzymes is too narrow a view when evaluating the cost of cellulosic ethanol production. Pretreatment methods and costs are directly related to enzyme costs and, therefore, reducing enzyme costs requires extensive collaboration between ethanol producer and enzyme producer.

In fact, everyone involved in developing enzymes, from manufacturers to producers to government researchers, believes collaborations are vital to reducing enzyme costs and commercializing the industry, and nearly every cellulosic ethanol producer is partnered with one or more manufacturing firm. “We’re very proud of all of our partners and the dedication that they’ve put into this because it’s not easy,” Novozymes’ Bryant says. “They really believe in this and they see the light at the end of the tunnel and we see them continuing to make progress.”

“We’re really getting to the stage as folks integrate these processes where we’ve got to work together to find the optimal system and understand the input costs from all the different directions,” Kelley says. That is, of course, easier said than done in many ways. Production processes vary so widely depending on feedstock and technology that enzyme manufacturers must address each facility’s specific needs. And while the industry is moving together jointly to commercialize the end-product, companies are still competing for market shares and must seek to protect their own intellectual property (IP). Bryant says that while some processes are more similar than others, most have a unique niche in one or all of three specific areas—feedstock, process technology and business model. “We work with each one on a very individual level because they are so unique,” she says. “The more open we can be with a partner and the more open they are with us, the quicker we’re able to meet our milestones and get to success. But this has to be tempered with the fact that there is concern about IP and IP ownership. It’s a real balancing act.”

Forging Ahead
Cellulosic ethanol enzymes may never be cost-comparative to starch ethanol enzymes but that perhaps should never be the goal, considering the complexity of the cellulosic systems makes it unfair to compare the two processes. “I think this is one of the most complex systems we’ve worked on,” Kelley says. He points out that starch ethanol uses two or three enzymes and requires various enzyme activities to digest the starch. “In the cellulose process you’ve probably got at least eight different families and multiple enzymes in each of those families of activities,” he says. “And all of those activities need to work together to get to your optimum yield and conversion.”

“The technical challenge of breaking down biomass is always going to be a lot more difficult than breaking down starch,” Aden says. Improving the productivity of the enzymes and activity of the overall system, all in a sustainable fashion, is what will continue to drive down the cost of the process, he says, and that is where enzyme manufacturers are focusing their efforts now. It will require dedication and significant continued financial investment, but those involved in the process don’t appear to be lacking motivation to continue. “Once you are in this business, this is something you don’t stop,” Santos says. “It is an ongoing process where you continue to improve and optimize technology that you are working on. The plan is to continue working on this package until we prove it.”

Author: Kris Bevill
Associate Editor, Ethanol Producer Magazine
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