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Design of highly CO2-soluble chelating agents for carbon dioxide extraction of heavy metals

Published online by Cambridge University Press:  03 March 2011

Ali V. Yazdi
Affiliation:
Chemical Engineering Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
Eric J. Beckman
Affiliation:
Chemical Engineering Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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Abstract

Carbon dioxide is an attractive organic solvent in today's chemical process environment, in that it is nonflammable, inexpensive, and exhibits low toxicity. Further, materials solubilized in carbon dioxide are easily and completely recovered/concentrated from solution via a simple pressure quench. Despite these favorable properties, CO2 is nonpolar and therefore is a very poor solvent for materials such as conventional metal chelating agents, thus blocking application of carbon dioxide in metal extraction/recovery. Consequently, we are exploring the molecular design of materials which are highly CO2 phillic, that is, they exhibit solubilities in carbon dioxide which are significantly greater than alkanes with the same number of main-chain atoms. By functionalizing chelating moieties with CO2-phillic oligomers, we have generated materials that both effectively extract metals from solid matrices and that dissolve in carbon dioxide in significant quantities. The application of such chelating agents is not limited to soil cleaning operations. In fact, these chelates make the use of CO2 possible in many applications where precision cleanup/recovery of metal ions are required. For example, CO2 has been promoted as a replacement for CFC's in cleaning processes in the electronics industry. Use of these chelates would allow the removal of metals, along with other impurities in a CO2 cleanup procedure.

Type
Environmentally Benign Materials and Processes
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1McHugh, M. A. and Krukonis, V. J., Supercritical Fluid Extraction, 2nd ed. (Butterworth-Heinemann, Boston, 1994).Google Scholar
2McLaren, L., Myers, M. N., and Giddings, J. C., Science 159, 197 (1968); Giddings, J.C., Myers, M. N., McLaren, L., and Keller, R. A., Science 162, 67 (1968).CrossRefGoogle Scholar
3Randolph, T. W., Clark, D. S., Blanch, H. W., and Prausnitz, J. M., Science 238, 387 (1988); Russell, A.J. and Beckman, E. J., Appl. Biochem. Biotech. 31, 197 (1991).CrossRefGoogle Scholar
4Desimone, J. M., Guan, Z., and Elsbernd, C. S., Science 257, 945947 (1992).CrossRefGoogle Scholar
5Hubert, P. and Vitzhum, O. G., Angew. Chem. Int. Ed. 17, 710 (1978).CrossRefGoogle Scholar
6Laintz, K. E., Wai, CM., Yonker, C. R., and Smith, R. D., J. Supercrit. Fluids 4, 194198 (1991).CrossRefGoogle Scholar
7Dandge, D. K., Heller, J. P., and Wilson, K. V., Ind. Eng. Chem. Prod. Res. Dev. 24, 162166 (1985).CrossRefGoogle Scholar
8Francis, A. W., J. Phys. Chem. 58, 10991114 (1954).CrossRefGoogle Scholar
9Harris, T. V., Irani, C. A., and Pretzer, R., US Patent No. 4,913,235, assigned to Chevron Research Co. (1990).Google Scholar
10Iezzi, A., Bendale, P., Enick, R. M., Turberg, M., and Brady, J., Fluid Phase Equil. 52, 307317 (1989).CrossRefGoogle Scholar
11Johnston, K. P., The University of Texas at Austin, personal communication.Google Scholar
12Stofesky, D., Reid, M., Hoefling, T. A., Beckman, E. J., and Enick, R. M., J. Supercrit. Fluids 5, 237241 (1992).Google Scholar
13Sucre, L. and Jennings, W., Anal. Lett. 13 (A6), 497501 (1980).CrossRefGoogle Scholar
14Hoefling, T. A., M. S. Thesis, University of Pittsburgh, PA (1993).Google Scholar
15Hoefling, T. A., Newman, D. A., Enick, R. M., and Beckman, E. J., J. Supercrit. 6, 165171 (1993).CrossRefGoogle Scholar
16Abu-Dari, K., Karpishin, T. B., and Raymond, K. N., Inorg. Chem. 32, 30523055 (1993).CrossRefGoogle Scholar
17“Further Development of LICADO Coal Cleaning Process,” Final Report, Science and Technology Center, Westinghouse Electric Corp., Pittsburgh, PA (September 1993).Google Scholar