DuPont's experimental station in Wilmington, Del., sprawls over more than 150 acres, one of the largest nonacademic research campuses in the world. Its roots lie in the 19th century, but today the station is home to 2,000 scientists, and many are trying to solve huge 21st-century problems: global warming, dependence on oil and feeding the world, to name a few. DuPont is exploring how a single solution can have an impact on all of them. The potential magic bullet: biofuel.
"The area of biotechnology, in general, and biofuels, in particular, provide a real opportunity for DuPont. Our whole effort is to do what we call integrated science, where you mix biology, chemistry, engineering, and materials sciences together," says John Pierce, vice-president of DuPont's bio-based technologies. Pierce manages most of DuPont's biofuels effort, nearly all carried out in the Wilmington area by two research teams.
As an alternative to petroleum, biofuels substitute plants and other waste for gasoline as its basis. In the United States ethanol and ethyl alcohol are derived from corn and comprise most of the US-produced biofuels. Ethanol is not without its critics or controversy, however, with claims that ethanol takes more energy to produce than it yields. A new report from the National Research Council (NRC) charges that increased corn ethanol production would have a profound impact on water quality and availability. Some groups, including DuPont, would like to wean the ethanol industry away from a grain-based feedstock and instead produce ethanol from stover, the stalks and leaves of the corn plant.
Ethanol and other biofuels made from corn do not even begin to exhaust the possibilities for inventing and manufacturing new biofuels. Pierce says that DuPont is assessing its technology for use with other feedstocks, such as straws and byproducts from current crops, as well as newer types of biomass, such as switchgrass. "Somewhat different process designs will be required for different feedstocks, but the general approach is similar," he says.
DuPont entered the biofuels market thanks to a project to create an industrial polymer out of something other than petroleum. The result was 1,3-propanediol (PDO), made from corn. In June 2007 a new plant in Loudon, Tenn., began churning out PDO at the rate of 100 million pounds per year.
Making PDO is near-classic industrial biotechnology. The process uses starch from feedstock such as corn grain or cobs and breaks it down into the simple sugars glucose and xylose. The sugars are mixed in a fermenter with microbes, in this case Escherichia coli, which have been engineered into PDO factories. Downstream purification and distillation complete the process.
DuPont realized that its industrial biotech process for making PDO could be adapted to produce other products, notably biofuel. With the help of a US Department of Energy grant in 2002, the company began working to extract sugars for fermentation, not from starches but from cellulose and lignin, the tougher insoluble materials that stiffen plant cell walls.
"We can't share a whole lot of the specifics," says Michael Sanford, who heads DuPont's cellulosic ethanol technology development. "The challenge we have in cellulosic ethanol is to take polymerized sugar in the form of cellulose and hemicellulose that's in the stalk or the cob of a corn plant and find a way to very cost-effectively depolymerize that carbohydrate into monomer sugars of glucose and xylose. We have a combination of chemical and biological approaches," adds Sanford.
The overriding goal of DuPont's biofuels research projects is to reduce process expenses, because biofuels can't succeed in the market unless they are no more costly than petroleum fuels. So, Sanford explains, a major focus of their R&D is to find better, cheaper enzymes.
Making cellulosic biofuels requires a diverse team that includes biochemists, molecular biologists to do genetic manipulation of the organism, process chemists, and chemical engineers. Team members work on optimizing and developing process steps, as well as economic analysis, Sanford says.
The essential team members are the microbes. "The heart of the metabolic engineering process is a biocatalyst, a microorganism," says William Provine, technology manager for DuPont biofuels. "It can be a bacterium or yeast that consumes sugar as a main component and produces fuels and chemicals within its cell. It's designed to expel the product of choice," he says. When the product of choice is ethanol, the microbe is the bacterium Xymomonasmobilis, which can eat both pentose and hexose sugars and turn them into ethanol at a high rate.
DuPont is also busy working on a new designer fuel, biobutanol. Butanol is butyl alcohol, which is more like gasoline than ethanol. Like ethanol, the fuel can be made from petroleum or from plants such as corn, beets, sugar cane, and wheat, and from other renewable sources. Butanol has a number of advantages over ethanol, including higher energy density and the ability to be transported through pipelines. (Transporting ethanol requires trucking it to terminals for blending with other fuels rather than the much less expensive transport via pipeline.)
A big hurdle for producing biobutanol is the design of the appropriate microbial factory. "We're looking at taking an organism that had not produced butanol before and designing the pathways into it to produce butanol," says Provine. The microbe is still in the research stage, so the company declines to disclose its identity. DuPont joined with BP (formerly British Petroleum) in June 2006 to build a demonstration plant in the United Kingdom. The partners say they will produce about 5,000 gallons of biobutanol a year and test it in vehicles.
In producing biofuels, DuPont's seeks to leverage its industrial biotechnology expertise in making ethanol and butanol from plant feedstocks. Another approach is to create the seeds that in turn create feedstock to provide sugar for the bugs that make the fuel. That seed work is done at Pioneer Hi-Bred International in Des Moines, Iowa, which has been producing hybrid corn seed for nearly a century, and which DuPont acquired in 1999. The result is mostly corn seed with biotech biofuel-friendly traits like easy-to-extract starch.
While most of the research is conducted in the Midwest, some is also done in Wilmington, Del. For example, Anthony Kinney's work modifying the meal and oil content of soybeans for all kinds of applications such as food, human, and animal. Kinney is senior research manager, Crop Genetics Research and Development. His group is developing a soybean with high oleic content, meaning that it's exceptionally low in saturated fat, like olive oil. That makes it healthful to eat but also useful for diesel fuel because high-oleic oils have lower emissions than conventional vegetable oils. Most diesel still comes from petroleum, but it can also be produced from several non-fossil sources. Kinney says, "We have some more long-term biotech efforts to increase the oil content of soybeans for biodiesel. High-oleic will begin to be commercialized in 2009. The high-oil soybeans are still in early development so we don't have a commercialization timeline for that yet."
Kinney has been with DuPont since 1989, a longevity that is uncharacteristic in today's scientific job market but fairly typical of DuPont scientists. DuPont is so huge that it is possible to have many different careers within the same company. Kinney points out that at the experimental station alone there is a large crop genetics research effort, but also research on polymers, biomaterials, and many other tech topics. "It's like a university," he says.
David Anton, a Californian came to DuPont 25 years ago is now the new venture manager at DuPont biofuels, with business responsibility currently for biobutanol. "Not only are you playing with the technology you grew up with, you also have to think about it in the context of what attributes society is going to want. How does it integrate with all the other kinds of businesses and value chains that are out there? It's really cutting edge, state-of-the-art, and involves interactions that you might never have thought would happen in a scientific career," Anton says. "It's that ability to come to work and know that what you do can make a difference, not only to the company but also to society, that keeps a number of us coming here. There aren't very many other places in the world where we could have done the PDO process, for example, that had the vision and the reach and the ability to stick at something for long enough to see it through to fruition."
Another big attraction is the region. "It's well-connected," says Kinney, noting that there are major universities within a short distance and the Delaware Technology Park in Newark close to the University of Delaware. "And there's a strong commitment by the state to biotechnology. There's a lot of interest from the governor and the Secretary of Agriculture in biodiesel and biofuels. There are a lot of good reasons for being here."