industry the position as they go forward to keep increasing their revenues by being able to diversify out into additional products.” The DuPont and ADM plants represent this first stage of the biorefinery development concept. The DuPont plant is collocated with an ethanol plant operated by Tate and Lyle PLC. ADM’s PHA facility is next to one of the company’s wet mills.
Breaking It Up A problem for biorefining, McMillan says, is that there is a critical difference “between a mixture of valuable chemicals and valuable mixture of chemicals. The latter is where you’re trying to end up. Biomass has everything in it. It is a mixture of valuable chemicals that isn’t very valuable when
shift production to its most profitable mix of products. “Another example is the sugar industry in Brazil,” McMillan says. “There you are taking a product—sugar—that can be made into ethanol. Then you ask which is more valuable, ethanol or sugar? You are taking the same starting material and asking, which way should I go, how do I break this down or fractionate to maximize my return and minimize my risk?” The pulp and paper industry is another player well-positioned for biorefining. It has a history of efficiently harvesting and transporting large quantities of biomass and separating it into its components. The BDC is a paid membership group of pulp and paper companies and their suppliers working to advance biorefining in the forestry industry in Wisconsin.
The biorefinery concept may be inevitable. Eventually, ethanol supply will begin to catch up with demand and, like the pulp and paper industry, the ethanol industry will start looking for ways to diversify its income stream.
they are all together like that.” Part of the challenge of biorefining is finding ways to economically capture the highvalue fractions of biomass. Biorefining advocates may be better off looking at different industries for inspiration. McMillan says one such model would be the corn wet milling industry. Starch is the product that pays the bills for these companies, but they also produce a host of other products including dextrose, high-fructose corn syrup, dextrans, corn oil, corn gluten and corn fiber. As market conditions change, the wet mill can
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“We are doing our investigation of the multiple pathways of transitioning paper mills into biorefineries,” Schutt says. “A paper mill is a little like a cow. You put the wood chips in a digester much like a cow’s stomach. Out of it comes cellulose that the paper companies want, but you can also pull out the hemicellulose.” Paper plants using the sulfite process for making pulp can also extract the hemicellulose, which can be broken down for ethanol and acetic acid production. However, there are only a few sulfite mills left because