Feedstock change is hot and poppin’

Corn, other renewable resources garner increasing interest and investment. Read here about the progress that is being made in discovering a new generation of feedstock.

By Bill Gerards, contributing editor

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BIO, the Biotechnolgy Industry Organization, Washington, D.C., notes that the benefits could include: new consumer products; new markets for the agricultural sector; the possibility of smaller, regional processing facilities around the country and around the world; energy savings; and reduced carbon dioxide emissions. A wide array of companies apparently find this combination appealing. “We’ve had quite a few new members lately” from the chemical sector, says Brent Erickson, vice president for BIO’s industrial and environmental section.

Carbon dioxide reductions will be especially attractive if woody biomass becomes an important feedstock, notes David Shonnard, a chemical engineering professor at Michigan Technical University, Houghton, Mich., and co-author of the book “Green Engineering: Environmentally Conscious Design of Chemical Processes.” Today’s reliance on fossil fuels, he says, acts “like a giant carbon pump working on a global scale,” bringing carbon from beneath the ground and sending it into the air, but the multiplication of plants and trees as feedstocks would “close the loop on carbon,” because such processes embrace the power of photosynthesis to remove carbon dioxide from the air while sending less of it back.

But Shonnard acknowledges several challenges that must be overcome. Wood is naturally resistant to degradation, so the enzymes and microorganisms needed to break it down are of a different order than those for corn kernels or some other renewable resources. The Natural Resources Defense Council, New York, in a 2004 report noted that “large scale penetration of cellulosic biofuels will require growing millions of acres of dedicated energy crops,” so early adoption of bio-based materials will rely more on agricultural and forest residues.

Shonnard also cites the chemical industry’s existing infrastructure as a possible obstacle to progress, partly because “the processes for converting these bio-based raw materials into products are different from the processes for converting fossil fuel materials into products.” Economic judgments justifying the changeover are complicated by the fact that environmental costs being paid by society under today’s fossil fuel regime are not well captured in the calculations watched by investors, he adds.

Different directions
Dow Chemical, Midland, Mich., took several steps assessing the costs and benefits of bio-based materials in 2005. It sold its stake in the Cargill Dow joint venture that produces polylactic acid (PLA) at Blair, Neb., from lactic acid derived from corn. But the company plans to retain bioprocessing in its toolbox, noting it “continues to make significant progress in its development of natural-oil-based polyols that can be used in lieu of a significant percentage of hydrocarbon-based polyols in urethane formulations.” Dow, which began research on such bio-based polyols in 2001, says it started product sampling with select manufacturers of flexible urethane slab in the U.S. and Europe in autumn 2005 and plans to continue the effort at least through this year.

The process for the “new family of vegetable-oil-based polyol products” developed and patented by Dow involves the disassembly of soybean or other natural oil feedstocks using a selective modification of the resultant fatty acids and the reassembly of the molecules into the desired product. “This process offers a number of advantages to both the manufacturer and the end-user,” Dow said in a statement to Chemical Processing. The ability to precisely tailor the degree of conversion of soy esters “allows for on-the-spot adjustment in the production of the bio-based polyols to compensate for the variation in the feedstocks.” The process also produces primary hydroxyl groups, yielding fast-reacting polyols that significantly enhance polyurethane foam’s processibility. Moreover, Dow says, a foam manufacturer can eliminate additional processing steps ordinarily needed to remove olefins — because the new process involves the complete hydrogenation of residual olefins, which helps to remove at their source odor-forming chemistries, which are common in natural-based polyols.

This development of natural oil polyols “is consistent with Dow’s effort to explore options to hydrocarbon-based feedstock challenges and opportunities, as well as supporting a sustainable environment,” Dow said in its statement.

Other initiatives include a production agreement announced early last year between Dow Haltermann Custom Processing and World Energy, Chelsea, Mass., a leading producer of biodiesel fuel.
Meanwhile, Cargill, Minneapolis, Minn., which has a number of active and planned investments and joint ventures for biodiesel and ethanol production in both the U.S. and Europe, has expressed wide-ranging interest in developing bio-based materials for the chemical industry. The company bought the Dow stake in their joint venture for PLA, which it calls the world’s first greenhouse-gas-neutral polymer made from corn. The PLA business, renamed NatureWorks in early 2005, now is focusing on the packaging market and has captured big customers like Wal-Mart, which currently uses NatureWorks PLA in some of its food packaging. Sales last year were projected to be more than 170% ahead of the 2004 level, a spokeswoman said.

Cargill says it made its first commercial sales of bio-based urethane polyols in the summer of 2005. The company also announced earlier last year that it had expanded a development agreement to use the proprietary olefin metathesis technology of catalysts company Materia, Pasadena, Calif. The aim is to convert bio-based oils to industrial chemicals, feedstocks and consumer products. Cargill sums up its bio-based enthusiasm with the estimate that “more than two thirds of the $1.5 trillion global industrial chemicals and plastics business could potentially be served by renewable materials.”

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