SCIENCE/TECHNOLOGY
Engineers Take Up Challenge Of Sustainable Development • AIChE meeting focuses on need for recycling and pollution prevention technologies, processes near commercialization Deborah L. Illman, C&EN Washington hemical engineers "can have a greater impact on achieving sustainable development than is possible through any other profession," contends Don V. Roberts, vice president of CH2M Hill. He defines sustainable development as "meeting the needs of the present without compromising the ability of future generations to meet their own needs." Roberts was one of the keynote speakers at the summer national meeting of the American Institute of Chemical Engineers (AIChE), held last month in Seattle. Waste minimization and pollution prevention are sustainable development concepts at the forefront of chemical technology. So it isn't surprising that these themes should infuse the chemical engineers' meeting, which looked at needs in these areas as well as showcasing advances on the verge of commercialization. AIChE program chairman William D. Byers notes that timing played a role. Planning for the conference, he says, happened to coincide with the June 1992 Earth Summit in Rio de Janeiro, which made sustainable development a natural choice for the meeting theme. Byers is director of air quality at CH2M Hill in Corvallis, Ore. As a result, sessions on pollution prevention were directed toward waste reduction in the aerospace, electronics, pulp and paper, mining and metals processing, and nuclear industries—all areas of special relevance in the Pacific Northwest region. By grouping these
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sessions together, explains Byers, the program committee hoped to foster cross-fertilization of ideas among practitioners in these fields. To reinforce his point, Roberts cited a speech given last year by Henry J. Hatch, chief of engineers at the U.S. Army Corps of Engineers. Speaking before the World Engineering Partnership for Sustainable Development, Hatch observed that sustainable development "requires doing more with less—less resource input and less waste generated. It requires new manufacturing processes, more use of recyclable materials, and the development of regenerative or recyclable output components. Instead of endof-pipe technologies alone, it requires pollution prevention ... [and] that we consider the life-cycle consequences of production. It requires an approach that imitates natural or biological processes and seeks new levels of the resource efficiencies of production." Another keynote speaker, Rep. Al Swift (D.-Wash.), called for better communication between technical experts and politicians, and outlined how engineers can provide much-needed input about new technologies to the political process. Swift is a member of the Energy
& Power Subcommittee of the House Committee on Energy & Commerce. Input from scientists and engineers is especially needed to help critically evaluate new recycling and pollution prevention technologies in terms of feasibility, cost, and efficiency, Swift says. He adds that regarding environmental cleanup operations, technical experts need to do more to help policymakers and the public understand the risks and costs associated with cleanup options. Some of the unmet technical needs in pollution prevention and sustainable development were addressed by Earl R. Beaver, technical director for waste elimination at Monsanto Chemical. Beaver is
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Swift, Roberts, Beaver (clockwise from top Hght) address sustainable development needs SEPTEMBER 13,1993 C&EN
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SCIENCE/TECHNOLOGY
Undergraduates square off in recycling contest A plastics recycling competition for undergraduate students was held at the American Institute for Chemical Engineer's (AIChE) summer national meeting last month in Seattle—a city well known for its ambitious recycling program. Cosponsored by the American Plastics Council, the Partnership for Plastics Progress, and AIChE, the competition drew more than 160 undergraduate engineering and chemistry students from across the nation who submitted ideas for novel recycling technologies. The challenge was to design a system that could recycle used plastics into marketable petrochemical products. Competing for cash awards, the top three finalist teams presented their plans at the meeting. A panel of 14 judges from industry, government, and academia evaluated the presentations based on criteria that included technical soundness, environmental impact, process economics, and payback. Chemical engineering students Mark Duso, Travis Thelen, and Timothy Toth from Michigan Technological University, Houghton, were first-place winners. A team of Johns Hopkins University, Baltimore, Md., students—Sam Baldwin, Timothy Harrah, and Chris Kirby—placed second, and a team from Louisiana State University, Baton Rouge—Jerome Acosta, Cang Nguyen, and Zhiyu Zhu—came in third. The Michigan Tech team won for a process employing a fluidized-bed reactor to produce a liquid product
responsible for identification, development, and application of waste elimination technologies across the company's five divisions. A member of both AIChE and the American Chemical Society, Beaver is trying to bridge the gap in this regard between chemical engineers and chemists. Among the most critical needs, says Beaver, are new synthesis and reactor designs that avoid use and generation of toxic and hazardous substances. Alternatives to the use of chlorine in synthesizing industrial products, for example, should be developed, he says, as well as new schemes for total reuse of water in process and cooling operations. Beaver stresses the value of cooperative efforts by industry, academe, and 36
SEPTEMBER 13,1993 C&EN
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Recycling contest winners (from left) Toth, Duso, Thelan of Michigan Tech "This event offers students the chance to work on a real-world problem that has no single right answer and for which solutions must balance technical and societal goals/' says event organizer Mark W. Meszaros, technical program manager in plastic solid waste management at Amoco Chemical, and project manager with the American Plastics Council. Finalists participated in a field trip on the day following the meeting session to a little town in Washington where big things are happening in recycling technology. Conrad Industries Inc., of Chehalis, Wash., in collaboration with the American Plastics Council, has developed a process that heats plastics in the absence of oxygen. The process breaks down the plastics into their basic components—a liquid petroleum stream that can be used to make new
government in pollution prevention. One such cooperative effort is AIChE's Center for Waste Reduction Technologies, an activity in which 27 sponsors have joined forces to carry out an array of educational, research, and other collaborative projects aimed at source reduction of waste in the chemical and petrochemical industries. Beaver is chairman of the advisory board of the center. The AIChE meeting showcased various waste reduction technologies that are now nearing commercialization. For instance, a scheme called "microwave-induced sulfur and hydrogen autolysis" is being developed in a joint Russian-American research program to recover hydrogen and sulfur from hydrogen sulfide waste streams. Presented
products; natural gas, which is used to fire the recycling unit; and residual solid carbon that can be sold for use in the production of materials such as pigments, activated carbon, and rubber goods. Conrad Industry's process may help surmount the problems of cleaning, sorting, and finding uses for recycled plastic materials. "This technology is at the forefront of what's happening worldwide," says Meszaros. "The students were impressed with the facility and were full of questions for the scientists and engineers involved in the project," Meszaros adds. "Seeing firsthand that organic and analytical chemists worked side-by-side with engineers showed them the importance of teamwork in tackling real-life problems."
by John Harkness of the energy systems division of Argonne National Laboratory, the approach is based on work originally described in the Russian literature. Hydrogen sulfide is fed into a plasma reactor, where it breaks down into elemental sulfur and hydrogen. Unlike conventional methods, the approach allows hydrogen gas to be reclaimed. The plasma-chemical reactor can be driven by either a microwave or a radio-frequency generator. When compared with the current technology, Harkness says, "the new process could save as such as $125 billion annually early in the next century. This could have a major impact on the refining industry." In addition, he says, "ancillary environmental benefits in-
elude lower sulfur dioxide and carbon dioxide emissions/' An industry working group with about six members has formed to help develop the technology. Another cooperative venture, focused on green cleaning technology using supercritical fluids to replace chlorofluorocarbons, was described by Dennis L. Hjeresen, program manager of applied environmental technologies at Los Alamos National Laboratory in New Mexico. Many efforts aimed at "green" technology are under way (C&EN, Sept. 6, page 26) at Los Alamos. The lab has established a user facility where companies can test cleaning technologies on real parts and equipment. Hjeresen says the facility now has a 60-L system running, the largest commercially available for supercritical fluid cleaning. By means of a piezoelectric sensor installed in the cleaning system, in-situ measurements of contamination removal can help determine appropriate end points for the supercritical fluid cleaning process. Membranes, too, are receiving increased attention for use in material recovery processes and pollution control. One example, described by Rod Ray of Bend Research, Inc., Bend, Ore., deals with a new type of reverse osmosis membrane for treating oily wastewaters. "Strict new government regulations pertaining to the discharge of oily wastewaters represents a significant technical and economic challenge for today's oil producers," says Ray. "Between one and 100 barrels of wastewater are typically produced per barrel of oil. This ... waste stream can contain oil and grease, dissolved organics, dissolved solids, and suspended solids. ... [The] majority of these contaminants must now be removed prior to disposal." The company has patented a special hollow-fiber membrane module that "exhibits exceptional resistance to fouling," says Ray. Feed solution is pumped through the insides of the hollow fibers. Purified water, which can be discharged or reused, passes through the fiber walls, while a concentrated solution of contaminants for disposal or recycling exits the ends of the fibers. By applying special coatings to the inside surfaces of the hollow fibers, the company can tailor membrane performance to particular applications. These include feed streams with high concentrations of organics or dissolved solids or those having high osmotic pressures. •
Groups report on advanced polymers
Cyclic oligomers form nonlinear optical resins
Μ'ΙΓ.»^.! Stephen C. Stinson, C&EN Northeast News Bureau Widespread efforts aimed at syntheses of advanced polymers are continuing to bear fruit. Although based on costly raw materials or employing complex processes, new polymers resulting from advances discussed in Chicago could be economically viable as parts of technology systems, if not on a cent-per-poundof-resin basis. Among the advances: • Organic chemistry professor David E. Bergbreiter of Texas A&M University, College Station, described a polymeric "smart" hydrogénation catalyst to the
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