About Chemistry, Environment, Waste Management and Green Life Inspirations

31 March 2010

Using "corrosion" to make ceramics

Form a metal precursor into a complex, shape, oxidize it, and get a ceramic with the same shape and dimensions.
Sometimes all it takes to solve a problem is to look at it from a completely different angle. For years, ceramists have been limited by their inability to form stable, complex shapes out of brittle metal oxides. Metallurgists, on the other hand, do everything they can to avoid forming metal oxides in the first place (they call them “corrosion products”). They can make any shapes they want out of malleable, ductile metals, but the resulting products don’t have the insulating and structural properties that ceramics have. When ceramic engineer Ken Sandhage joined a group of metallurgists, he didn’t see metal oxides as a problem, but as the beginning of a solution.
When Sandhage was earning his Ph.D. in ceramic engineering at the Massachusetts Institute of Technology in the early 1980s, he selected a metallurgist, Greg Yurek, as his adviser. Although he was the only ceramist in Yurek’s group at the time, this turned out to be an advantage—he gained more exposure than most ceramists to the theory of metal oxidation.
“Most work in this area has been done by metallurgists and electrochemists,” points out Sandhage, “so few ceramists know much about it, even though high-temperature metal oxidation is basically a ceramic process.”
Because metals are consumed by oxidation, metallurgists consider oxidation to be a type of corrosion that they would, of course, like to prevent. On the other hand, Sandhage realized that metal alloys that oxidize rapidly would be great as ceramic precursors or as nonfugitive binders. “This is using oxidation of metals from an opposite perspective. Instead of treating oxidation as metallic corrosion, oxidation can be considered to be an attractive processing route to ceramics or metal–ceramic composites,” Sandhage says. This idea became the basis for the development of the volume-identical metal oxidation (VIMOX) process and similar processes.
Laying the groundwork
But this would come later. First Sandhage had to earn his Ph.D., which involved studying the high-temperature corrosion of alumina in multi-silicate melts (slags) containing magnesia. Sandhage wanted to understand the corrosion of ceramic refractories used in coal gasifiers. Such refractories often contain Al2O3 that can react with the MgO in the slag to form spinel, MgAl2O4. He initially attempted to apply the Turkdogan–Wagner model for the active oxidation of volatile metals (1, 2) to describe the rate of this ceramic corrosion reaction, but he eventually realized a different model was needed.
He observed that in this ceramic reaction, Al2O3 dissolved incongruently in the corrosive slags; the Al2O3 dissolved by first forming a continuous, adherant layer of spinel that then, in turn, dissolved. Under steady-state conditions, the spinel formed and dissolved at equal rates, so that the spinel layer achieved a constant thickness on the Al2O3. Sandhage was able to describe this incongruent dissolution process with the use of the Tedmon model for the oxidation of chromium, which involves the simultaneous formation and volatilization of a continuous oxide layer with a constant thickness (3). As a result of his research, Sandhage realized that his knowledge of metal oxidation could be used effectively in modeling and understanding ceramic reactions and in developing new ceramic processes.
After working in the field of fiber optics for a few years, Sandhage joined his adviser at a start-up company called American Superconductor. Here, Yurek and his colleagues made oxide composite superconductors by selectively oxidizing yttrium, barium, and copper from alloys containing these elements and silver, resulting in a YBa2Cu3O7–Ag composite.
After 3½ years at American Superconductor, Sandhage decided to pursue oxidation-based research and develop other types of ceramics and ceramic composites in an academic setting. In 1991, he became a professor in materials science and engineering at Ohio State University, where he had to come up with a novel area of research. With his background in oxidation and a seed grant from the university, Sandhage started research in the oxidation of alloys containing alkaline and alkaline earth metals.
Sandhage went back to work done in the 1920s, when Pilling and Bedworth were looking at why oxidation rates differ in metals (4). Pilling and Bedworth considered the volume of oxide produced divided by the volume of metal consumed (now known as the Pilling–Bedworth ratio or PBR) to be an important parameter, and they evaluated this ratio for several metals. Most metals have a PBR > 1, whereas alkali and alkaline earth metals tend to have a PBR < 1 (Table 1).
Sandhage believed that if he could combine the right types of metals to form a precursor, so that the net volume change upon oxidation of the precursor was small or zero, he could convert complex-shaped metal-bearing precursors by oxidation into near net-shaped ceramic materials. (A net-shaped material has the same shape and size before and after processing. Most ceramics contain pores that cause them to shrink or deform when they are fired.) Metals tend to be ductile and relatively easy to form into complex shapes. On the other hand, ceramics traditionally have been difficult to make into complex parts without using expensive diamond machining to achieve the desired dimensions. By starting with easily formed metal precursors, then oxidizing the precursors to yield ceramics that retain the precursor shape and dimensions, near net-shaped ceramics can be produced without the need for ceramic machining. The VIMOX process is based on oxidizing different metals in a precursor (some of which expand, some of which contract upon oxidation) to limit the volume change upon conversion into a ceramic compound.
The VIMOX process
Sandhage and his students toiled for several years to demonstrate that the VIMOX process could be used to produce a number of technically useful ceramics and composites in near net shapes, such as those shown in Table 2 (6). During this time, Sandhage received support from several federal and state agencies for such research. In 1995, he was granted a patent for the VIMOX process (7).
The VIMOX process comprises several steps (Figure 1). First, precursors are prepared by mechanically alloying powders of metals and oxides to obtain a uniformly dispersed mixture with the proper phase content (for minimal volume change upon oxidation) and overall composition (for the desired final ceramic or ceramic composite). Next, the mixed powders are compacted and shaped by one or more of several metallurgical processes (e.g., pressing, rolling, drawing, machining). The amount of ductile metal in the precursor determines the type of fabrication process that is used. Approximately 30 vol% of ductile metal is used for pressing and about twice that for rolling and drawing.
Once the preforms are made into desired shapes, they are oxidized and converted into the final ceramic or ceramic composite using several heat treatments. These heat treatments can effect oxidation, compound formation, microstructural tailoring, or other desired processes. By carefully controlling the phase content of the precursor and the heat treatments, near net-shaped ceramics and composites can be produced without costly post-oxidation machining steps. Furthermore, because modest temperatures (300–500 °C) can be used to oxidize alkaline earth metals, the grain size of the resulting oxide can be quite small, so that subsequent sintering also can be done at modest temperatures. (Dense BaTiO3 has been produced at 1080 °C, several hundred degrees lower than normal, without a sintering aid.)
A casting process can also be used to prepare the precursors (Figure 2). A block of solid alkaline earth metal is placed in contact with a porous preform in the desired shape. The metal is melted under an inert atmosphere, causing it to infiltrate the pores of the preform. Heating the preform under oxygen produces a ceramic in the shape of the original preform that contains the alkaline earth metal.
One advantage of precursors containing alkaline earth metals is that they are ductile at room temperature, which makes them easy to machine and form into shapes. They are also easy to cast into shapes because of their low melting temperatures. Thus, the VIMOX process using these materials can make ceramics that retain shape, volume, and dimensions after oxidation, usually to within 1%.
In contrast, conventional ceramic processes require the use of organic binders that must be burned off the ceramic preform, producing high internal porosity. Such porosity produces significant distortions and shrinkage upon sintering, 20% or more, depending on the amount of binder used to form the ceramic preform (more for rolling, less for pressing). Since 1991, Sandhage’s group has produced a variety of functional ceramics by the VIMOX process, including biocompatible phosphates, ionically conducting cerates, dielectric titanates, superconducting cuprates, magnetic ferrites, and refractory aluminates and aluminosilicates for biomedical, sensor, electronic, magnetic, optical, chemical, and high-temperature applications.
Displacive compensation of porosity
One limitation of the VIMOX process is the thickness of parts produced. Parts thicker than several centimeters can take relatively long times (tens of hours) to oxidize completely. This limitation has recently been overcome with another oxidation-based process developed by Sandhage’s group, known as the DCP (displacive compensation of porosity) process. In 1998, graduate student Pragati Kumar was preparing preforms to spinel by infiltrating molten magnesium into porous Al2O3 and then solidifying the magnesium. He noticed that the Al2O3 had oxidized some of the magnesium to MgO during infiltration. After realizing that an oxidation–reduction reaction was occurring during infiltration, Sandhage and Kumar calculated the change in ceramic volume for this reaction:
3{Mg} + Al2O3 → 3MgO + 2{Al}
where {Mg} and {Al} refer to magnesium and aluminum dissolved in molten metal. To their surprise, more ceramic volume was generated than was consumed. They then decided to let this reaction run to completion during infiltration (reactive infiltration). They found that porous alumina preforms could be converted completely into dense, high MgO-bearing components with little change in shape or dimensions.
In other words, the increase in volume caused by the displacement reaction could be used to compensate for the porosity in the starting preform; hence, the term DCP. Because the oxygen source for such a displacement reaction is the solid oxide that is distributed throughout the preform, long-range diffusion of oxygen from outside of the preform is not required to complete this reaction. Once the molten metal fully infiltrates the preform (which occurs rapidly), the time required for complete reaction does not depend on the size of the preform. Sandhage’s group has since identified a variety of other volume-increasing displacement reactions that can be used to make components with a high ceramic content (Table 3).
The DCP process consists of two steps: infiltration of a molten metal into a porous, shaped ceramic preform and an in situ reaction of the molten metal with the ceramic preform (Figure 3). Because the volume of solid ceramic produced is larger than the original volume in the preform, dense composites with relatively high ceramic contents can be synthesized. If the metallic product of the reaction is solid at the reaction temperature, dense ceramic–metal composites are produced. If the metallic product is molten, the metallic liquid is squeezed out of the preform as the pores become filled with ceramic, and the composite contains a very high ceramic content. This latter process is called “pressureless reversible infiltration of molten alloys by the displacive compensation of porosity” (PRIMA-DCP).
A range of compositions and phase contents can be produced by varying the melt composition, the preform porosity, and the preform phase content. (The metal reinforcements in the composites can be continuous or discontinuous.) For example, composites of MgO/Mg–Al with MgO contents ranging from 70 to 86 vol% can be produced by varying the preform porosity from 47 to 29% (17). Composites with >80 vol% MgO were found to be electrically insulating; sufficient molten metal was extruded from the preform during reaction that only discontinuous particles of metal remained in the composite upon cooling to room temperature.
The DCP process also has been used to produce co-continuous MgAl2O4/Fe–Ni–Al composites by pressureless reactive casting of Mg–Al liquids at 900 °C into porous Fe/NiAl2O4 preforms with the net reaction:
4/3{Mg0.75Al0.25} + xFe(s) + NiAl2O4 → MgAl2O4 + y[Fex/yNi1/yAl1/(3y)]
where y = x + 4/3; 4 ≤ x ≤ 8; and the brackets {} and [] refer to liquid and solid alloys, respectively.
Composites with a variety of oxide and metal alloy compositions can be produced directly by DCP or PRIMA-DCP processes for use in electrical, refractory, insulating, or engine applications.
Nonoxide ceramic composites
The DCP process can also be used to make composites containing nonoxide ceramics. Sandhage recently worked with several senior undergraduate students to fabricate ZrC–W composites by the reactive casting of a Zr2Cu liquid into porous WC preforms (18). The net displacement reaction in this case is
0.5{Zr2Cu} + WC → ZrC + W + 0.5{Cu}
The residual molten copper does not form stable compounds with ZrC or tungsten and has minimal effect on the high-temperature resistance of the final material. Copper also has the advantage of lowering the reactive infiltration temperature and can be extruded out of the preform as the pores are filled. Dense, near net-shaped composites were produced within 2 h at 1200 °C and 1 h at 1300 °C.
Such composites are attractive for high-temperature applications where excellent resistance to creep, erosion, or thermal cycling is required, for example, throat inserts of rocket exhaust nozzles. Current nozzle liners are based on carbon or tungsten. Although tungsten exhibits minimal oxidation in solid-fuel rocket nozzles, and it has a very high melting point and good toughness, it is heavy (19.3 g/cm3) and relatively difficult to form into specific shapes at room temperature. Combining tungsten with ZrC is an alternative because ZrC is relatively lightweight (6.63 g/cm3) and chemically compatible with tungsten. This combination has better strength and toughness than ZrC alone.
However, the ZrC–W composites prepared by conventional methods are difficult to sinter, requiring hot pressing at 2000 °C and 20 MPa. They are also expensive to machine. Sandhage and his students have shown that the DCP process can produce ZrC–W composites in the desired shapes without machining at 1200 °C and ambient pressure. Furthermore, functionally graded ZrC–W composites can be produced by carefully tailoring the distribution of tungsten and WC in the starting preforms (19).
Sandhage has purchased a larger furnace for scaling up the DCP process. This furnace will be capable of making rocket nozzles that can be tested in rocket burner rigs at Edwards Air Force Base, CA (in collaboration with Wesley Hoffman of Edwards AFB).
Sandhage has also submitted a proposal to the U.S. Army to evaluate the use of the DCP process for making custom-tailored body armor. In this case, a plaster of Paris mold the exact shape of the torso is produced first. A slurry of silicon carbide is then cast into the mold. After drying, this porous preform is then infiltrated and reacted with a boron-bearing liquid to convert the porous SiC preform into lightweight, hard B4C–SiC composite armor that retains the preform shape and dimensions:
4{B} + (1+x)SiC → B4C + xSiC + {Si}
where {B} and {Si} refer to boron and silicon dissolved in a liquid solution. By tailoring the starting porosity and SiC particle size in the cast preform, Sandhage expects that near net-shaped B4C–SiC composites with tailored phase contents can be produced.
Although DCP is somewhat of an offshoot of VIMOX and can also produce net shapes at lower temperatures than conventional processes, there are major differences between the two approaches (Table 4).
Joint efforts expand applications
Sandhage is working with other Ohio State researchers to develop new applications for the VIMOX process. He has teamed up with Alan Litsky, a professor of orthopedics, to develop graded oxide coatings for metal hip implants. The pure oxide coatings of hydroxyapatite currently used do not adhere well to the underlying metal stem for long periods. A new graded hydroxyapatite coating concept has been demonstrated with the VIMOX process; the next step will be to make implants for animal studies after additional funding is obtained.
Sheik Akbar, a colleague in the materials science and engineering department, and Sandhage are investigating making TiO2-doped MgCr2O4 humidity sensors that can be reused after exposure to high temperatures. The VIMOX process produces near net-shaped sensors that can be positioned close to the ceramic ware to allow for local measurement of the drying rate. Placed on kiln cars, these humidity sensors could determine the drying rates of ceramic ware to allow for energy- and time-efficient rate-controlled drying.
One novel application of DCP takes advantage of marine biology, namely a type of green algae called diatoms. These single-celled creatures form microshells with intricate shapes and with submicrometer features. While on sabbatical in 1991 as a Humboldt Fellow in Germany, Sandhage met Australian marine biologist Monica Schoenwaelder, an expert on diatoms. After discussing her work, Sandhage came up with the idea of using diatoms as templates to make near net-shaped microdevices.
One application would be drug delivery biocapsules. Capsule-shaped diatoms, made of amorphous silica, have been reacted with magnesium to form MgO capsules that retain the diatom capsule shape. Because MgO is more biocompatible than SiO2,drugs could be easily and safely administered in MgO capsules. Capsule-shaped diatoms could also be converted into CaO, adding the benefit of dietary calcium to those who need it.
Eventually, Sandhage believes, genetic engineering can be used to tailor the diatom shape, and he has coined the term “genetically engineered microdevices” or GEMs. DCP would be used to tailor the composition and convert the silica into other ceramics or ceramic composites. Sandhage has applied for a patent (20) and expects to obtain seed money for further development.
“In addition to their size and shape advantages,” adds Sandhage, “diatoms have an extremely high replication rate of 3–8 times per day. This means you could theoretically make 1 billion similar microdevices in just 10 days. Genetically engineered diatoms could be used as biofactories to mass-produce large numbers of micro templates with similar tailored 3-D shapes that could then be converted by reaction into microdevices with tailored compositions for microsensors, micromotors, microrobots, etc.”
Bringing the products to market
After spending a decade conducting several millions of dollars worth of oxidation-based research and obtaining seven patents in metal oxidation technology, Sandhage is now actively working to commercialize the VIMOX and DCP processes. Orton Ceramic Foundation (Westerville, OH) is continuing development of the MgCr2O4 humidity sensors.
Sandhage believes that the VIMOX and DCP processes have great potential for commercially manufacturing ceramic and ceramic composite components with complex shapes. He warns, however, that “it is not easy to insert new processes into traditional ceramic manufacturing companies, especially since these companies are often not familiar with powder metallurgy or casting metallurgy-based processes. This requires a significant change in mindset.” Sandhage is thinking about starting his own company that will act as an intermediary to manufacture and test components.
Acknowledgments
Ken Sandhage has received research funding from the National Science Foundation, the U.S. Department of Energy, the U.S. Air Force Office of Scientific Research, and the Edison Materials Technology Center (Dayton, OH).

Back to the basics
The basic kinetic mechanism or mechanisms by which oxides undergo incongruent reduction with molten metals (DCP reactions) are not well understood. Sandhage and colleague Robert Snyder at Ohio State recently were awarded a National Science Foundation grant to study these reactions. The main objective of this research is to develop a fundamental understanding of the rate-limiting steps and microstructural evolution by which a solid oxide undergoes incongruent reduction with a reactive metallic liquid. A better knowledge of such reaction mechanisms will help predict how changes in processing conditions will affect reaction times, composite microstructure, and, consequently, the composite properties. In situ X-ray diffraction (XRD) will be used to track, in real time, the formation of spinel (MgAl2O4) on Al2O3 surfaces immersed under molten Mg–Al layers. This is possible because the absorption of MoKα X-rays by Mg–Al liquids is relatively low. This is the first time that dynamic X-ray analysis will be used to study liquid metal–solid ceramic displacement reactions underneath molten metal (Figure 4).
The in situ XRD method requires making novel graphite heating cells that are transparent to X-rays. With these heating cells, the entire preform and surrounding melt can be equilibrated thermally, avoiding the steep thermal gradients normally seen when heating strips are used. Dynamic in situ thermogravimetric analyses will also be used to determine the steady-state rate of incongruent reduction under well- controlled conditions.
References
  1. Turkdogan, E. T.; Grieveson, P.; Darken, L. S. J. Phys. Chem. 1963, 67, 1647–1654.
  2. Wagner, C. Corros. Sci. 1965, 5, 751–764.
  3. Tedmon, C. S., Jr. J. Electrochem. Soc. 1966, 113, 766–768.
  4. Pilling, N. B.; Bedworth, R. E. J. Inst. Metals 1923, 29, 530–591.
  5. Encyclopedia of Materials: Science and Technology; Buschow, K.H.J., Ed.; Elsevier: New York, 2001.
  6. Sandhage, K. H.; Allameh, S. M.; Kumar, P.; Schmutzler, H. J.; Viers, D.; Zhang, X.-D. Mater. Manuf. Processes 2000, 15, 1–28.
  7. Sandhage, K. H. U.S. Patent 5,447,291, 1995.
  8. Kumar, P.; Sandhage, K. H. J. Mater. Res. 1998, 13, 3423–3435.
  9. Viers, D. S.; Sandhage, K. H. J. Am. Ceram. Soc. 1999, 82, 249–252.
  10. Schmutzler, H. J.; Antony, M. M.; Sandhage, K. H. J. Am. Ceram. Soc. 1994, 77, 721–729.
  11. Ward, G. A.; Sandhage, K. H. J. Am. Ceram. Soc. 1997, 80, 1508–1516.
  12. Saw, E.; Sandhage, K. H.; Gallagher, P. K.; Litsky, A. S. Mater. Manuf. Processes 2000, 15, 29–45.
  13. Schmutzler, H. J.; Sandhage, K. H.; Nava J. C. J. Am. Ceram. Soc. 1996, 79, 1575–1584.
  14. Citak, R.; Rogers, K. A.; Sandhage, K. H. J. Am. Ceram. Soc. 1999, 82, 237–240.
  15. Jain, A.; Sandhage, K. H. In Innovative Processing and Synthesis of Ceramics, Glasses, and Composites IV; Bandal, N. P., Singh, J. P., Eds.; American Ceramic Society: Westerville, OH, 2000; pp 15–23.
  16. The Powder Diffraction File [CD-ROM], International Centre for Diffraction Data: Newtown Square, PA (2001 update).
  17. Kumar, P.; Sandhage, K. H. J. Mater. Sci. 1999, 34, 5757–5769.
  18. Dickerson, M. B.; Unocic, R. R.; Guerra, K. T.; Timberlake, M. J.; Sandhage, K. H. In Innovative Processing and Synthesis of Ceramics, Glasses, and Composites IV; Bandal, N. P., Singh, J. P., Eds.; American Ceramic Society: Westerville, OH, 2000; pp 25–31.
  19. Dickerson, M. B.; Snyder, R. L.; Sandhage, K. H., Presented at the 25th Annual Cocoa Beach Conference and Exposition, Cocoa Beach, FL, Jan 2001. Submitted for publication.
  20. Sandhage, K. H. U.S. Patent application pending.

Laurel M. Sheppard is a freelance writer based in Hilliard, OH (lashpubs@infinet.com). She has a B.S. in ceramic engineering from Ohio State University, Columbus.

A simple process for removing chloroform from water

Chloroform in water is a byproduct of the chlorination process (1). Bathing or showering in chlorinated tap water exposes individuals to chloroform by ingestion, inhalation, or dermal contact. Some epidemiological studies have suggested that exposure to chlorinated water causes bladder cancer (2, 3) and is associated with rectal cancer (3) and potential birth defects (4). Several studies, including some based on exhaled breath analysis, suggest that significant dermal exposure to chloroform occurs while showering, and the dose is roughly comparable to that resulting from inhalation (5, 6). (Breath analysis measures the time elapsed between first skin contact and when the chloroform is first observed in the exhaled breath.) Other studies have extended this work to swimming in indoor pools (7, 8). Most of these investigations have used breath measurements to determine total exposure.
We have proposed a process to remove chloroform from water. The process was tested and found to be adequate by public health standards for water that contains a concentration of chloroform up to 6.7 g/L.

Figure 1
Figure 1. A two-step process removes chloroform from water. Contaminated water is fed into a convection tank, where it passes through a “curtain” of compressed air. The air removes the chloroform from the water, and a charcoal bed removes the chloroform from the air. The purified air is released to the atmosphere.
We use an air curtain convection tank (Figure 1) coupled with a carbon bed system located at the air exit (9–11). This process provides rapid, efficient mass transfer of the chloroform from the liquid phase to the gas phase (11). The location of the air curtain and the flow rate of the compressed air have been optimized with respect to mass transfer and good mixing. Compressed air is injected into the convection tank through series of 16 equally spaced perforations (1.6 mm diam) in a single row along a transverse tube to create fluid circulation with an air curtain. The tube is placed centrally across the width of the bottom of the tank.
Saka and Doi (10) found that carbonized woody materials effectively adsorb chloroform from water and benzene from the atmosphere. Using their technique, we fed the air exiting the aerated tank into a charcoal-packed bed. This air contains chloroform and a small amount of water. The packed bed consists of a Perspex U tube (2 cm diam, 10 cm high) filled with granulated charcoal 0.5 mm in diameter. This shape was the most effective for reducing the concentration of chloroform in air.
We started with 5 L of water containing 18.25 g of chloroform. Air at 5 L/min aerated the water via the perforated pipe. The air exited the water tank, then passed through the carbon bed. The exhaust from the carbon bed was vented to the atmosphere.
(Figure 2) shows the change in the concentration of chloroform in water when air was blown into the contaminated water for 90 min. Gas chromatography was used to analyze for chloroform in the water. After 90 min, the concentration of chloroform in water went almost to zero. The chloroform was then removed from the air exiting the tank using the U-shaped charcoal bed. The air exiting the carbon bed was assumed to be free of chloroform (10).
This simple, novel process is very effective in eliminating chloroform from water. We believe that this method will be useful in protecting our environment from such a harmful pollutant.

References

  1. International Agency for Research on Cancer. Chlorinated Drinking Water; Chlorinated By-Products; Some Other Halogenated Compounds; Cobalt and Cobalt Compounds. IARC Monographs on the Evaluation of Carcinogenic Risk to Humans, Vol. 52; IARC: Lyon, France, 1991.
  2. Cantor, K. P., et al. J. Natl. Cancer Inst. 1987, 79, 1269–1279.
  3. Morris, R. D.; Audet, A. M.; Angelillo, I. F.; Chalmers, T. C.; Mosteller, F. Am. J. Public Health 1992, 82, 955–963.
  4. Bove, F.; Fulcomer, M. C.; Savrin, J. E. Am. J. Epidemiol. 1995, 141, 850–862.
  5. Jo, W. K.; Weisel, C. P.; Lioy, P. J. Risk Anal. 1990, 10, 575–580.
  6. Wester, R. C.; Maibach, H. I. Environ. Sci. Pollut. Control Ser. 1994, 9, 149–165.
  7. Wallace, L. A.; Nelson, W. C.; Pellizzari, E. D.; Raymer, J. H. J. Expo. Anal. Environ. Epidemiol. 1997, 7, 141–163.
  8. Lindstrom, A. B.; Pleil, J. D.; Berkoff, D. C. Environ. Health. Perspect. 1997, 105, 636–642.
  9. Fenelon, J. M.; Moore, R. C. Occurrence of Volatile Organic Compounds in Ground Water in the White River Basin, Indiana, 1994–1995; U.S Geological Survey Fact Sheet 138-96, U.S. Government Printing Office: Washington, DC, 1996.
  10. Saka, S.; Doi, M. Mater. Sci. Res. Int. 1998, 4, 249–253.
  11. Pleil, J. D.; Lindstrom, A. B. Clin. Chem. 1997, 43, 723–730.


Omar Chaalal is an associate professor of chemical engineering in the University General Requirements Unit at United Arab Emirates University (PO Box 17720, Al-Ain Abu Dhabi, U.A.E.; ochaalal@uaeu.ac.ae).
Ali Dowaidar is a research assistant in the chemical engineering department at United Arab Emirates University.

Educating an engineer

The University of Pittsburgh has a new learning center for undergraduate chemical engineering students. The authors describe its innovative aspects and student and faculty reactions.
The Chemical and Petroleum Engineering Department at the University of Pittsburgh perceived a need to improve the existing classroom space to accommodate increased class sizes. A study team was formed in 1998 to identify classroom design options that would meet the department’s functional needs, based on the positive results that other universities had achieved by applying active and collaborative learning methods. The study team established the following design and operational goals for a new learning center:
  • facilitate and promote team-based classroom activities,
  • provide support for computer-facilitated classroom exercises consistent with active collaborative learning pedagogies,
  • ensure good visibility and interactivity between students and the professor,
  • be distinctive so that the students and the faculty would be proud of this unique asset, and
  • provide a central “hub” for the department’s students and faculty.
We started our program with extensive benchmarking of other universities that were using advanced classroom facilities. Many institutions helped form the database of “best practices”, but special thanks go to the Office of Planning Engineering and the Electrical Engineering Department, Rensselaer Polytechnic Institute (RPI) (1); the Chemical Engineering Department at the University of Massachusetts, Amherst (2); and the Center for Innovation in Engineering Education, Arizona State University (3). The willingness of these institutions to share their concepts, designs, and experiences was most helpful in the excellent outcome for the learning center. Its implementation was made possible through the generous support of Frank L. Mosier, an alumnus of the department. In appreciation of his support and leadership, it has been named the Frank Mosier Learning Center.
RPI’s experience (4) and that of the two other institutions we had benchmarked, as well as positive results from collaborative and active learning assessments that emerged from National Science Foundation–sponsored trials (5, 6), influenced the design of the layout and the audiovisual and computer systems.
In the course of benchmarking, several issues became “must do” priorities for the new learning center:
  • Good visibility. Many computer-facilitated classrooms have become burdened with computer monitors. Large computer screens sitting on top of tables can become a major impediment to visibility and interaction within the room. Meeting graphics and visibility needs was a high priority.
  • Good acoustics. CPU fans from many computers in a room can produce substantial background noise. Methods to reduce room background noise needed to be explored.
  • Ease of support. Hardware and software maintenance can be substantial for a facility with 30 or more PCs. Means to minimize the level of maintenance effort had to be examined fully.
  • Customized desktops. Whereas the preliminary list of software that the faculty requested was large (~24 different packages), the software required for any one class was small (1–5 packages). Customizing desktops for each class would be a desirable feature.
  • Minimal distractions. Because this was a classroom and not a computer lab, we wanted to minimize the distractions of e-mail and the Internet (except when desired by the instructor for a specific class).
  • Capacity. The operational needs of the department dictated that the learning center accommodate 75 students.
The center had four major design components: the room, the furniture, the computer system, and the audiovisual equipment.

Figure 1- photo of tinted window wall between learning center and 
hall
Figure 1. Tinted window wall between the learning center and the hall (used at both entrances).

Figure 2- student desk with LCD monitors
Figure 2. Student desk with LCD monitors.
Figure 3 - podium showing control stations
Figure 3. Podium showing control stations.
Figure 4- photo of learning center
Figure 4. Overall view of the learning center.

The room

The existing classrooms that could be converted dictated the space available for construction of the learning center. The room is 30 ft deep × 65 ft wide. Part of the strategy to make the space unique and distinctive was to use tinted glass window walls adjacent to the entrances, as shown in Figure 1. Other elements of the redesigned room included raising the floor to accommodate the power and computer cabling to the desks and the podium and reconfiguring the HVAC (heating, ventilation, and air conditioning) to meet aesthetic and operational needs. Acoustic panels were added to the ceiling to minimize echoes.

Furniture

Early design decisions included the type and number of computers and the size and placement of monitors to meet the visibility requirement. The choice of computers and accessories had a substantial impact on the room layout and the furniture design.
The visibility requirement and, specifically, avoiding obstructions caused by monitors led the design team initially to consider monitors with nonglare glass tops built into student tables. Although this approach has been used successfully elsewhere, the additional requirement for promoting teamwork made the monitor-in-the-table approach unsatisfactory because of the difficulty of several team members peering into the “hole” in the table. Thin-screen LCD monitors were considered but deemed unsatisfactory because of the image and color distortion caused by viewing the monitors at an angle during team-based activities. This limitation was overcome when Acer View (San Jose, CA) offered an LCD monitor that has a 160° viewing range.
The availability of suitable thin-screen LCD monitors permitted the final design of the student desks, shown in Figure 2. The desk requirements included
  • accommodating five students (because of the room size and the need to have two- or three-person teams);
  • hosting two PC monitors, as well as the CPUs and peripherals (keyboard and mouse), and meeting the visibility requirements; and
  • providing writing space and storage space for the peripherals when not in use.
We decided on a commercially available telemetry system from Cybex (Huntsville, AL) so that the students’ CPUs could be located remotely. The Cybex units were installed under the students’ desks, one for each PC. These units permitted the remote location of the CPU and avoided having two CPUs at each table. (This remote location approach is discussed further in the following section.) The resulting student desk design fully meets the requirements for visibility, low noise (from computer fans), and the facilitation of teamwork and active learning via the PCs. The Cybex system also reduces the space requirements of accommodating 30 PCs in the learning center.
The podium had aesthetic and functional requirements; it was designed to complement the decor of the learning center and to house electronic equipment and the instructor’s PC (see Figure 3 and the following section).
The finished learning center is shown in Figure 4. The room was decorated with technical photography highlighting departmental activities.

Computer system

The basic computer system consists of 30 student PCs and an instructor’s PC. They all use the AcerView F51 LCD monitor and run under the Windows NT operating system. The overall configuration of the student PCs, the instructor’s PC, the server, and the network switch is shown in Figure 5.
The faculty was surveyed for software needs, and a suite of software was selected to meet the department’s requirements. Twenty-four software packages available in the learning center. The full complement of software is always available on the instructor’s PC, but the system was designed to have the desktop of the student PCs customized for each class. This ensured that only the software needed by an instructor is available for that class without other installed software that can distract students. The desktop can be modified by the system administrator to add or remove software for all 30 PCs in less than 5 minutes through the Novell Netware on the server.
Figure 5 - flow diagram
Figure 5. Configuration of learning center PCs and server.

Figure 6 - photo of pc room
Figure 6. Overall view of PC room.

Figure 7- picture of computer touch screen
Figure 7. Tech Electronics touch screen controller.
Netware provides several major functions. It allows login administration for individual classes, the instructor, and the system administrator. Most classes have a generic login for each class. File storage is via individual folders on the server, but not password-protected by individual students. For selected classes, where deemed appropriate, each student has an individual login. Netware also offers desktop management by class. The system administrator can create an account for each class. Then, by using ZenWorks, the administrator can add or delete any of the software packages available to the students in that class. Netware also provides file management, described later.
Remotely positioned computers. The student computers are not physically located in the learning center. Using the Cybex telemetry, the CPUs are in a separate room, as shown in Figure 6. The decision to place the PCs remotely was based on the concern about fan noise and limited space in the learning center. The configuration selected ensures adequate seating and workspace for five students at each table. This approach also minimizes the wear and tear on the PCs by the multitude of students who use them.
The file management system. The instructor can install files that are available to students on a read-only basis from a class-specific file folder on the server. The student can load the applicable file into the application (e.g., Microsoft Excel). Because the file is read-only, the students cannot save files to the location from which the file was opened. If a student tries to save work to the source file folder, a read-only designation appears.
Students can access template files that have been placed on the network by the instructor. After completing a classroom exercise, the students can save their work in the “student file” section on the server and transfer these files via the learning center network to their personal file space on the University of Pittsburgh’s UNIX timesharing system. This file export system is necessary because of the remote location of the PCs (no disk drives in the learning center). The arrangement has worked well. These file transfers are done with Ipswich WS-FTP software through the university LAN. A similar procedure can be used to transfer files into the learning center (e.g., homework).
Computer interaction. The podium is equipped with a touch-screen panel from Tech Electronics (Norcross, GA), so the instructor can set four modes of display and control the students’ PCs (see Figure 7):
  • Stand-alone: Each PC functions independently through the server and network switch as shown in Figure 5.
  • Instructor-to-student: The students’ monitors display what is on the instructor’s PC, and the students have no control of their PCs (Figure 8).
  • Student-to-instructor: A selected student’s PC also displays on the instructor’s PC (Figure 9). The instructor can optionally take control of that student’s PC to demonstrate the proper methodology on a problem.
  • Student-to-student: The work on a student’s PC is broadcast to the other students’ monitors at the instructor’s discretion (Figure 10).

Audiovisual system

The control aspects of the audiovisual system are built around a Crestron controller. Using the touch panel controller, the following functions are available to the instructor:
  • system power (main power, video projector);
  • lights—six lighting circuits are individually controlled for room illumination;
  • video source (document camera, VCR, video camera);
  • computer (podium PC, portable PC);
  • controller for 35-mm projector; and
  • audio system (microphone volume, program volume).
These are state-of-the-art devices and have served the needs of the faculty and students well.

Implementation, utilization, and reception

The students and the faculty have embraced the functional and aesthetic aspects of the learning center. One of the cultural outcomes that we strove for was an improved sense of community and better networking among students in the department; the behavior and feedback of the students clearly indicate that these goals have been achieved.
The faculty have adapted to the new instructional tools and opportunities for modified pedagogies. The learning center has only been operational for one year. Although each faculty member’s rate of adapting to the new system is different, essentially all have switched from the old overheads to Microsoft PowerPoint for visuals.
Beyond that, other changes include the use of Web-based lecture notes, which are delivered to each LCD monitor in the learning center, and full implementation of active learning, such as short lectures, in-class work on a PC-based problem (accessed by the students from the server), and group discussion of assignments.
The faculty continue to modify and adapt class format to make full use of the capabilities available. Formal evaluation of changes in learning and retention will be made on the basis of student assessments made before and after implementation of the learning center; preliminary qualitative feedback is very positive. Likewise, the faculty’s feedback has been quite positive.
The effort needed to support the advanced technology in the learning center has been minimal. A computer specialist is on contract for one day a week to make upgrades and changes to the computer system. Beyond several minor startup problems, the overall system has been essentially maintenance-free.

Early outcomes

We have completed two semesters and the summer session, and most of the department’s classes were held in the learning center. The database is relatively small in terms of quantitative assessment, but we can report some significant observations and trends.
The faculty have applied the new computer and audio visual facilities in the learning center in varying degrees. For classes in which a substantial transition to a cooperative or collaborative learning pedagogy took place, a review of student evaluations of the instructor showed that on average, the “overall” rating of the instructor increased by 15%, compared with previous evaluations by classes without the new capabilities. The most dramatic change was in the evaluation category “ability to solve engineering problems”, in which the average increase was almost 20%. Such changes are significant when the transition occurred in two adjacent semesters. A review of the ratings of the other instructors during the same time showed that no substantial change occurred in the ratings of those who used the new audiovisual capabilities but did not include cooperative and collaborative learning in their classes.
We requested student evaluations of the learning center, and these narrative assessments have been positive as well. They also identified some minor adjustments to improve functionality, which either have been implemented or are in progress.

Recommendations for further development

Because of the extensive and successful predesign benchmarking and the coordination of the design team with the faculty, the learning center has fulfilled all of the identified needs and expectations. If we had the luxury of selecting the dimensions of the room to be used, our preference would be to have a room that was deeper and narrower, that is, more nearly square.
Document cameras come in a wide range of resolutions. For optimal performance in an engineering environment, the highest resolution three-chip camera might be beneficial, but the $14,000 cost can be prohibitive. Alternative products to capture in-class lecture notes include electronic whiteboards and plasma screens. These devices must be reviewed to determine which approach best meets the needs of your students and faculty.
The Tech Electronics system’s ability to “broadcast” the instructor’s notes or slides to the students’ flat-screen monitors has been very successful. For an additional learning center in the School of Engineering at the university, the design team has eliminated the large-screen, high-intensity video projectors, so the only “projection screens” will be the students’ monitors. In the new room, the document camera has been replaced with a scanner and a plasma screen that the instructor can use for in-class writing.
Every institution will have different requirements and budgets that will dictate the approaches outlined here. However, we believe some issues are clear.
  • Cooperative and collaborative learning does improve students’ reception to materials presented. Other studies (4–6) have clearly shown that these pedagogical techniques also enhance students’ performance and their ability to apply new skills.
  • The available technology facilitates “active learning”; however, to realize the benefits, it is necessary that the faculty not be intimidated by new technology and overcome any reluctance to break typical engineering problems into 10- to 15-min “bits”.
  • To meet the needs and expectations of today’s students and faculty, the basic design concepts described here must be seriously considered.
  • The department has found substantial value in the new learning center and will share (at no cost) its design philosophy and implementation details with other departments. Please contact us to discuss possible collaboration.

References

  1. Maby, E.; Holmes, O.; Bequette, B. W.; Laplante, B. Rensselaer Polytechnic Institute, Troy, NY, personal communication, 1998.
  2. Malone, M. F. University of Massachusetts, Amherst, personal communication, 1998.
  3. Doaks, B. Arizona State University, Tempe, personal communication, 1998.
  4. Maby, E.W.; Carlson, A. B.; Connor, K. A.; Jennings, W. C.; Schoch, P. M. A Studio Format for Innovative Pedagogy in Circuits and Electronics. In Proceedings of the 27th Frontiers in Education Conference; IEEE, 1997; Vol. 3, pp 1431–1434.
  5. Felder, R. M.; Brent, R. Cooperative Learning in Technical Courses: Procedures, Pitfalls, and Payoffs; ERIC Document Reproduction Service, ED 377038, 1994.
  6. Felder R. M. J. Eng. Educ. 1995, 84, 361–367.


John N. Murphy is a visiting research professor at the University of Pittsburgh (Chemical and Petroleum Engineering Dept., School of Engineering, 1249 Benedum Hall, Pittsburgh, PA 15261; 412-624-9923; murphy@engrng.pitt.edu). His principal research interests are workplace and laboratory health and safety, advanced learning systems, and the application of computer-based training and virtual reality for improved and more cost-effective training. He received his B.S. degree in engineering from the University of Pittsburgh and his M.B.A. from Duquesne University; he is a Registered Professional Engineer.
Alan J. Russell is chair of the Chemical and Petroleum Engineering Dept.; Nickolas DeCecco Professor of Chemical and Petroleum Engineering; professor of molecular genetics and biochemistry at the University of Pittsburgh; and executive director, Pittsburgh Tissue Engineering Initiative Inc. (412-624-9631; russell@engrng.pitt.edu). His principal research emphasis is applied enzymology and tissue engineering. He received his Ph.D. in chemistry at Imperial College of Science and Technology, London.
Anthony B. Jones is a systems analyst and administrator at the University of Pittsburgh (Computing Services & Systems Development, 717 Cathedral of Learning, Pittsburgh, PA 15260, 412-383-9631; abj@pitt.edu). He received his B.S. degree in computer science from the University of Pittsburgh and is a Certified Novell Engineer. His work at Pittsburgh since 1991 has involved design, implementation, support, configuration, and migration of university computing systems and laboratories and management of technical staff.

cartoon of mechanic talking to scientist
"I see you've applied the team-based learning approach to your lesson on tensile strength."

Global warming: Are attitudes changing?

artwork by Scott Roberts

Three years after the historic signing of the Kyoto Protocol, the international treaty on reducing greenhouse gas emissions, the author seeks answers from some of industry’s top executives.
It wasn’t long ago that industry views on global climate change were dominated by skeptics. When the first international treaty on greenhouse gas emissions (see box, “Kyoto Protocol basics” for a detailed discussion) was brokered in Japan in 1997, many industry critics scorned the effort as the work of “wild-eyed” greens. The view held by most industrial producers was that the science on global warming was inconclusive and that forcing costly emissions reductions on a regulated schedule could destroy the U.S. economy.
Kyoto Protocol basics
The Kyoto Protocol is the first internationally binding treaty on reducing emissions of greenhouse gases. Signed by 150 nations in Kyoto, Japan, in December 1997, the protocol seeks to reduce worldwide emissions of carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride to 5% below 1990 levels by 2008–2012. Country-specific reduction targets vary from –8 to +10%; some underdeveloped countries are actually allowed to increase their emissions. The target for the United States is 7% below 1990 levels. Signing the protocol merely signifies intent to comply. A country is held to its mandated target once it deposits an instrument of ratification, something only 24 countries have done so far. The origins of the protocol date back to the 1992 United Nations Conference on Earth and Development (the so-called Rio Earth Summit) held in Rio de Janeiro. This meeting produced the United Nations Framework Convention on Climate Change (UNFCC), which sought to stabilize greenhouse gas concentrations in the atmosphere to levels that would minimize climatic interference. Much of the language in the Kyoto Protocol was derived from this original document. The UNFCC designated the developed countries as Annex 1 and the underdeveloped countries as non-Annex 1 parties to the convention.
The Kyoto Protocol has been the subject of considerable debate. In the United States, some members of Congress have sought to prevent ratification, believing that requirements for developing countries are too lenient and unfairly saddle developed countries with the bulk of emissions reductions. In 1997, 6 months before the protocol was formally unveiled in Japan, Senators Robert Byrd (D-WV) and Robert Hagel (R-NE) introduced legislation prohibiting the United States from ratifying the protocol unless the agreement also mandated emissions reductions from developing countries within the same period. This Byrd–Hagel resolution has formed the legislative foundation for congressional opposition to any measures that seek to implement Kyoto Protocol provisions in the United States. At this time, the likelihood that the U.S. Congress will ratify the Kyoto Protocol appears slim; however, it is possible that more countries other than the United States will ratify the treaty over the next several years.
Using advertising campaigns to dispel the notion of global warming, powerful industry groups lobbied Congress against emissions restrictions for greenhouse gases, which include carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. Global warming theories hold that these gases ascend to the atmosphere and trap heat on the earth’s surface like windowpanes on a greenhouse. Cut to 2000 and this picture has changed dramatically. Industry has been forced to contend with evidence that global warming is a real and immediate problem. The previous decade was the warmest on record, with each of the past 3 years being successively warmer than the last. On the northern and southern extremes of the planet, glaciers have been melting at an unprecedented rate. Recently, a mile-wide patch of ocean opened at the North Pole, something scientists don’t think has happened for more than 50 million years. A draft report titled Climate Change Impacts on the United States, issued by the National Science Foundation in June, predicts continuing increases in global temperatures of between 5 and 10 °F over the next century, with a range of potential effects on health and the environment (1).
It is debatable whether these events have anything to do with industrial emissions, but their appearance now, ominously coincidental with climate modeling predictions, appears to be having an impact on public opinion. According to a 1998 survey by the World Wildlife Fund, ~60% of Americans believe global warming is a real problem (2). Furthermore, a March 1999 survey conducted by the Mellman Group, a Washington, DC–based polling organization, found that 76% of 450 congressional officials, industry association leaders, media representatives, economists, scientists, and policy experts think U.S. action is necessary to reduce greenhouse gas emissions (3).

A shift in the mainstream view

With these views now typifying the mainstream, the old guard critics in industry are increasingly on the defensive. For example, the Global Climate Coalition (GCC), an influential Washington, DC–based industry group—known for its hard-line skepticism on global warming and intense lobbying efforts against legislated controls—has softened its tone while trying to improve its radical image. Once the leading voice for corporate America in the climate debate, GCC has suffered a series of high-profile defections, including Ford Motor Co., Royal Dutch–Shell Group, Dow Chemical Co., and DaimlerChrysler Corp. An article in The Economist derided the GCC as a “spent force” (4). Speaking from the Ford Office of Environmental Strategy, Philip Colley, company public affairs spokesperson, explained why Ford decided to leave the group. “Going through the GCC had been a useful way for us to interface with the government on global climate issues,” he said. “But the GCC became a lightning rod for critics of the industry and membership was impeding our own environmental agenda.” GCC’s spokesperson, Frank Maisano, acknowledges that its affiliated companies increasingly saw membership with the organization as a public relations liability. As a consequence, in late summer of this year, the GCC restricted its membership to trade associations, something that Maisano hopes will help to “refocus attention on the climate debate rather than who is a member and who isn’t.”
While the GCC struggles to retain its relevance, other more moderate groups are taking center stage in the inter national debate about global warming. Perhaps the most influential is the Pew Center for Global Climate Change, an independent organization with funding from such sources as the Pew Charitable Trust, whose own industry group—the Business and Environmental Leadership Council—boasts a roster of blue-chip companies whose annual sales exceed $500 billion. Its 28 current members include industrial giants BP Amoco, Shell International, United Technologies, and DuPont.
The GCC and the Pew Center agree that climate change is a serious issue that warrants industry action, but their views differ in several key ways. Among their chief differences is that the GCC continues to lobby against all mandated controls on emissions, whereas the Pew Center believes that controls are necessary to address and reduce the ongoing problem of global warming. Eileen Claussen, the president of the Pew Center, says, “All our member companies agree in principle with the concept of a binding emissions reduction treaty. And they are all comfortable with me saying this on behalf of their involvement with the Pew Center.”
Whether acceptance of mandated controls “in principle” extends to the Kyoto Protocol is a whole different question. At press time (which predates a pivotal meeting for Kyoto delegates held in early November at The Hague), the protocol was referred to as flawed by the GCC and the Pew Center. Although most stakeholders see the protocol as loaded with a variety of problems (e.g., limited involvement by developing countries), the key issue for even the most treaty-friendly companies is the short timeframe for compliance among nations. For example, the United States is held to a 7% reduction below 1990 levels by 2008–2012, a target that Claussen concedes is totally unrealistic. “It doesn’t take an engineer to see that a 7% reduction is overly ambitious in a country where emissions have already grown to more than 11% above 1990 levels and are likely to continue to rise,” said Claussen at a speech in London in June (5). But Claussen acknowledges that with more flexible deadlines and a clear road map for reducing emissions, a binding treaty—maybe even a revised version of the Kyoto Protocol—could be agreeable to the Pew Center companies.

Explaining the shift

The question of whether or not mandated controls are needed to address climate change is probably the most conspicuous issue for companies on either side of the debate. The result is that for some companies, mandated controls would produce serious economic hardships. According to John Grasser, vice president of external communications at the National Mining Association, the coal mining industry could be “killed off” by mandated controls. But beyond this example, it is not obvious which industry sectors stand to lose the most, because the vulnerability of companies depends on many factors, such as market diversification, available capital, and technical resources. Furthermore, companies that position themselves to take advantage of mandated controls could come out ahead, should controls come to pass. Therefore, it is not unusual to see two companies in the same industry sector with sharply diverging views on the issue. Connie Holmes, chair of the board of the GCC, says, “It doesn’t matter if you’re talking about utilities, the oil industry, the automobile industry, or any industry, you’ll find a range of opinions within each of them on whether climate change is happening and what the best strategies are for dealing with it.”
Another source of disagreement is an emerging concept in environmental policy called the “precautionary principle”, which holds that in situations in which serious or irreversible damage is possible, lack of full scientific evidence should not stand in the way of actions designed to prevent environmental damage. The concept has many advocates when it comes to highly charged and scientifically ambiguous issues, of which climate change is a clear example. Some companies exploit the uncertainty of global warming to justify minimal action in lieu of more definitive data, whereas others act unilaterally to reduce their emissions.
Consider the differences between BP and ExxonMobil, both giant multinational oil companies that should have a similar stake in the debate. BP, a former GCC member, is now entrenched in the Pew Center philosophy and has released a statement claiming that “the precautionary approach to climate change is the only sensible way to progress in light of the uncertainty over the issue.” As part of a program to green its operations, BP has set a goal to achieve a 10% reduction in greenhouse gas emissions below 1990 levels by 2010. On the other hand, ExxonMobil has consistently downplayed the science of global warming and rejected precautionary approaches for dealing with it. Chair Lee R. Raymond has stated, “We do not have a sufficient scientific understanding of climate change to make reasonable predictions to justify drastic measures.” Consequently, ExxonMobil has not set an internal timetable for reducing emissions, but rather, is continuing to make “investments in environmental technologies”.
Observers point to several factors that might explain the opinion differences among companies. First, BP is headquartered in the United Kingdom, where pro-environment views dominate across the political spectrum. In the United States, home of ExxonMobil, skeptics retain a good deal of political influence, which lessens the threat of mandated controls. On a broad level, European (and Japanese) companies may lean toward the precautionary principle and an acceptance of mandated controls out of political motivations. There are some notable exceptions. For example, DuPont’s green reputation on the topic of climate change is almost unsurpassed in any industry. DuPont committed to reducing greenhouse gases in 1991 and claims to have cut its emissions by 45% since then.
Second, BP’s investment in alternative capabilities, particularly hydrogen fuel cells and solar energy, is considerably greater than that of ExxonMobil. Some observers suggest that companies investing in alternative energy markets stand to gain considerably from mandated controls and that this explains their more “progressive” positions. Jeff Morgheim, BP’s climate change manager, vehemently rejects this suggestion. “I put this in the realm of conspiracy theory,” he says. “If anyone thinks we can push binding reductions on the world community then we have a lot more power than I ever dreamed of. The fact is that we believe the world is headed for a decarbonized energy economy that someday may be carbon free. And we are positioning ourselves to take advantage of it.”
Third, the influence of a company’s chief executive should not be underestimated. BP’s CEO John Browne has a long history of aligning himself with environmental causes and has worked to orient the company around precautionary ideals—providing what Morgheim calls a “well-entrenched and lasting legacy that goes beyond any one person.”
Claussen describes the role of the chief executive as “absolutely crucial”. “I think it makes all the difference in the world,” she says. “When you look at Pew Center companies that have set internal targets, almost all of them have CEOs who are engaged on the issue of global warming, for example, Chad Holiday at DuPont, Mark Moody-Stewart at Shell, and George David at United Technologies.”

Voluntary programs

If stakeholders tend to agree on anything, it is that voluntary industry action will be necessary to address future environmental problems. In fact, the GCC promotes voluntary programs and new technology as the cornerstone of its agenda, rooted in the belief that market solutions can handle global warming (if indeed industry has anything to do with it) without any regulatory interference. In the absence of a binding regimen for reducing emissions, companies have been free to develop their own climate programs, and many have done so to varying degrees. Specific activities vary by industry and include improving process efficiency in industrial operations, reducing energy consumption, finding ways to sequester carbon, and many others. According to a 1999 fact sheet released by the GCC, “[In 1998] nearly 190 companies and organizations from nearly every industry sector reported on more than 1500 [emission reduction] projects to the Energy Information Administration, the Department of Energy’s statistical and forecasting arm” (6).
Some of the greatest initial successes come with finding the “low-hanging fruit”, that is, actions that yield environmental results without much economic pain. Obviously, the low-hanging fruit varies among companies: For United Technologies, it was energy conservation; for BP, it was limiting fugitive emissions from gas lines; and for DuPont, it was limiting releases of non-CO2 greenhouse gases such as nitrous oxide and halocarbons.
The overriding question is “will voluntary programs be sufficient over the long haul?” According to Maisano of GCC, environmental technologies spawned by voluntary programs will build on each other and yield exponential emissions reductions into the future. But will these technologies keep up with industrial growth? Even Maisano describes them as “the great unknown”; he concedes, “We can’t predict how well they are going to perform.”
Most environmental managers worry about sustaining their climate change programs once the low-hanging fruit is plucked and their companies merge and expand operations. Morgheim commented, “We’d like to grow the companies we have now at several percent a year. The challenge is to grow organically without increasing emissions, and this is where we see the costs start to go up. It’s going to take some radical thinking about how we achieve efficiency in our plants and platforms.”
At some point, voluntary programs might get so expensive that they could begin to compromise a company’s position in the marketplace. Claussen says this is one of the reasons the Pew Center believes that in addition to voluntary programs, mandatory controls will also be necessary—they level the playing field for industry. Another problem with a strictly voluntary approach, she adds, is the lack of any mechanism for ensuring that emissions control programs are equally effective. Pointing to the existing situation, she says, “Some of these programs are good; some are not so good. And not everyone has voluntary programs. This is one of the reasons emissions are up by 11% overall since 1990.”
Ironically, some multinational companies that reject the notion of mandated controls may have to adhere to them anyway if they conduct business in countries that ratify a binding instrument to reduce greenhouse gas emissions. And indeed this is one of the key remaining questions about the Kyoto Protocol: Will sufficient numbers of countries ratify the protocol to bring it effectively into force despite the objections of the United States? This question, and many other concerns regarding the future effects of global warming, remain unanswered.

References

  1. Climate Change Impacts on the United States: Potential Consequences of Climate Variability and Change (draft report); National Science Foundation, National Assessment Synthesis Team: Washington, DC, June 12, 2000 (under review).
  2. Survey of the National Voter Data; World Wildlife Fund: Washington, DC, 1998.
  3. Presentation and Analysis of Findings for the Pew Center for Global Climate Change; Mellman Group Inc. and Wirthlin Worldwide: Washington, DC, March 1999.
  4. Changing the Climate of Opinion. The Economist, Aug 12, 2000; www.economist.com (available on the Web by subscription only).
  5. Claussen, E. Kyoto: The Best We Can Do or Fatally Flawed? Speech presented at Royal Institute of International Affairs Conference, London, June 20, 2000.
  6. 1999 Inventory of Industry Voluntary Actions (fact sheet); Global Climate Coalition: Washington, DC.


Charles W. Schmidt is a freelance writer on science-related topics (171 Danforth St., Portland, ME 04102; 207-772-9672; cschmidt@gwi.net).

New Fuels: An “artificial leaf” for turning sunlight into fuel


Scientists are working to create an
“artificial leaf” that imitates a living leaf’s
chemical photosynthesis process to
convert sunlight and water into a liquid
fuel like methanol for cars and trucks.

Credit: National Aeronautics and Space
Administration (NASA)
(High-resolution version
)

Summary

    Scientists are making progress toward development of an “artificial leaf” that mimics a real leaf’s chemical magic with photosynthesis — but instead converts sunlight and water into a liquid fuel such as methanol for cars and trucks. That was among the topics at the 1st Annual Chemical Sciences and Society Symposium, initiated though the American Chemical Society Committee on International Activities.
Leaves are a natural part of our everyday surroundings. But many people fail to appreciate their importance. Leaves provide us with shade, food, valuable medicines, breathtaking scenery, and even the oxygen we breathe.
Scientists are now making progress toward development of an “artificial leaf” that mimics a real leaf’s chemical magic with photosynthesis, but instead converts sunlight and water into a liquid fuel such as methanol for cars and trucks. That is among the conclusions in a new report from top authorities on solar energy who met at the 1st Annual Chemical Sciences and Society Symposium. The gathering launched a new effort to initiate international cooperation and innovative thinking on the global energy challenge.

Julie Callahan, Ph.D.,
Image courtesy of
American Chemical Society
The three-day symposium, which took place in Germany this past summer, included 30 chemists from China, Germany, Japan, the United Kingdom, and the United States. It was organized through a joint effort of the science and technology funding agencies and the chemical societies of each country, including the U.S. National Science Foundation and The American Chemical Society, the world’s largest scientific society.
A paper describing highlights of the symposium notes that the sun provides more energy to the Earth in an hour than the world consumes in a year. Compare that single hour to the one million years required for Earth to accumulate the same amount of energy in the form of fossil fuels. The paper notes that fossil fuels are not a sustainable resource and urges us to break our dependence on them. Solar energy is among the most promising alternatives.
The scientists pointed out during the meeting that plants use solar energy when they capture and convert sunlight into chemical fuel through photosynthesis. The process involves the conversion of water and carbon dioxide into sugars as well as oxygen and hydrogen. Scientists have been successful in mimicking this fuel-making process, termed artificial photosynthesis, but now must find ways to do so in ways that can be used commercially. Participants described progress toward this goal and the scientific challenges that must be met before solar can be a viable alternative to fossil fuels.
Highlights of the symposium include a talk by Kazunari Domen, Ph.D., of the University of Tokyo in Japan. Domen described his current research on developing more efficient and affordable catalysts for producing hydrogen using a new water-splitting technology called “photocatalytic overall water splitting.” The technology uses light-activated nanoparticles, each 1/50,000th the width of a human hair, to convert water to hydrogen and oxygen. He said that the technique is more efficient and less expensive than current technologies.

Kazunari Domen, Ph.D.,
Image courtesy of
Kazunari Domen,
University of Tokyo
Here is Dr. Domen to describe the process:
    “Scientists have tried for many years to develop a way to split water molecules, similar to what leaves do during photosynthesis. My new process captures light and splits water using one device. It is one of the few water-splitting devices that uses visible light instead of ultraviolet light.” “Current water-splitting systems have still only less than one percent solar energy conversion efficiency. We are trying to achieve a much higher efficiency of between 5 to 10 percent. If we can do that, then we will have an “artificial leaf” technology that is cheap and practical to use on a large scale.” “We are very excited about the future our new “artificial leaf” technology for helping solve the world’s energy problems. My dream is to use the device to collect large amounts of solar energy in a desert area and then use that energy to develop chemical fuels such as methanol and ammonia. These fuels can then be used to power a car or generate electricity.”
Domen noted that the ultimate goal of artificial photosynthesis is to produce a liquid fuel, such as methanol or “wood alcohol.” Achieving this goal would fulfill the vision of creating an “artificial leaf” that not only splits water but uses the reaction products to create a more usable fuel, similar to what leaves do.
Julie Callahan, Ph.D., of the ACS Office of International Activities and principal investigator for the project, expressed hope that the solar energy symposium would be the first of an ongoing series of scientific symposia to tackle global challenges of the 21st century.
Here’s Dr. Callahan:
    “Building on the success of this first symposium, we’re now gearing up for the future, convening top chemical scientists to address other, equally pressing global challenges. It is an exciting time to be a chemist.”
Smart chemists. Innovative thinking.
That’s the key to solving global challenges of the 21st Century. Be sure to check our other podcasts on fuels [Biofuels and The Sun and More]. Today’s podcast was written by Mark Sampson. I’m Adam Dylewski at the American Chemical Society in Washington.

11 March 2010

CERA Week: Natural Gas Industry Looks To Shore Up Demand

By Jason Womack 
   Of DOW JONES NEWSWIRES 
 
HOUSTON (Dow Jones)--The natural gas industry is grappling with a big problem: trying to find an outlet for vast new supplies of the fuel.
The boom in domestic natural-gas production from onshore natural-gas fields known as shales has dominated much of the discussion at the IHS Cambridge Energy Research Associates conference. And while many industry executives and experts agree that a global economic recovery will eventually lead to the long-term demand growth needed to absorb excess supply, near-term demand remains stunted.
"We need to be better about the facts and hopefully, over time, that will build more support for gas," said Helge Lund, president and chief executive of Statoil ASA (STO), which is investing billions in U.S. shale-gas development.
Over the course of the conference, executives have promoted the fuel as a secure and robust domestic energy source that provides a low-carbon alternative to other fossil fuels, and they encouraged attendees to do the same.
"It's a no-brainer," Steven Farris, chief executive of Apache Corp. (APA), said during a panel discussion at which he advocated wider use of natural gas as a transportation fuel. "I truly believe that we are going to use more natural gas in this country."
The pressure to peddle the commodity comes after the economic downturn undermined demand - particularly among industrial users, which account for about a third of domestic consumption. Prices have plunged more than 65% from their 2008 summer highs above $13 a million British thermal units.
However, some see price volatility falling away as producers continue to tap new fields and secure low-cost supplies that will compete more effectively against coal, a staple fuel source for electricity generation in the U.S.
"We should expect relatively low prices for the long term," Chad Deaton, chief executive of oilfield-services provider Baker Hughes Inc. (BHI).
Still, Deaton said during a panel discussion that industry participants--from those developing technology to producers, to utilities--need to agree on a pricing framework to make the economics of the business work.
-By Jason Womack, Dow Jones Newswires; 713-547-9201 jason.womack@dowjones.com