Sustainability Is Where You Find It

At Pacifichem, the conference is set up so that you tend to want to just drift around and stick your head into one meeting room for a talk and them skip out to another session for a different talk.

Lush volcanic hills rise from downtown Honolulu, as seen through the metal and glass framework of the Honolulu Convention Center. Credit: Steve Ritter/C&EN

Doing that one afternoon, I came across a talk by Rogers E. Harry-O'kuru of the U.S. Department of Agriculture's National Center for Agricultural Utilization Research, in Peoria, Ill., who was speaking about novel synthetic products that could be made from milkweed. Milkweed, which literally is a weed in agricultural areas, can ideally be cultivated on unused farmland, Harry-O'kuru said. The plant produces a fibrous "seed floss," which equips the seeds for wind dispersal, that can be used as a hypoallergenic fill material for pillows and jackets, he noted. The seeds also contain a highly unsaturated oil that can be converted to polyoxiranes and polyhydroxy triglycerides to use as base materials in creams and lotions or as lubricants, he said. What struck me about Harry-O'kuru's lecture is the ingenuity of people to turn whatever they have at hand into useful products that potentially cost little and can help improve the environment. These talks have applications globally, especially in developing countries. I then noticed a handful of other talks strung together by the common theme of sustainability: Kyoung S. Ro of USDA's research center in Florence, S.C., gave an interesting talk on gasification of blended animal manures to produce synthesis gas and activated carbon. Pig and chicken poop mixed with sawdust and wood chips can be converted to syngas, which can be burned to generate electricity or further upgraded to dimethyl ether that can be used as a diesel fuel substitute. The whole process can be carried out in a transportable reactor, with the char left behind purified and used as activated carbon filter material in the reactor. Guillermo Toriz of the University of Guadalajara, in Mexico, gave a talk on the diversified uses of agave, the plant that is used to make tequila. The waxing and waning popularity of tequila has led to a severe overproduction of agave in Mexico, Toriz said, which has obliterated the price for farmers from about $2.00 per kilogram to about 5 cents per kilogram, making it uneconomical to harvest. Toriz described some new uses for agave that could help farmers: Enzymatic production of high-fructose-content agave syrups, using fructans (fiberlike polysaccharides) in agave as food additives and prebiotics that help promote growth of beneficial bacteria in the human gut, and using esterified fructans to make microspheres to encapsulate and deliver drugs to the colon. Janusz Kozinski of the University of Saskatchewan described the use of supercritical water as a medium for converting dead pine trees into biofuels. This is an interesting possible use of large quantities of lodgepole pine in western Canadian forests--stands of trees have been decimated by the mountain pine beetle. Kozinski is developing a continuous reactor system for converting the lignocellulosic material into biofuels or chemicals. Each of these examples shows how chemical ingenuity can be used to take seemingly unusable waste products and turn them into something useful.

Author: Steve Ritter

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