Page 288 - Adsorbents fundamentals and applications

REFERENCES 273

(XAD-16) is compared with that on activated carbon in Figure 9.25. Resins have
the highest hydrophobicity among all sorbents. Based on the water capacity at
low relative humidities, XAD-16 is of the order of 100 times more hydrophobic
than activated carbon.
Such a high hydrophobicity gives resins a distinct advantage over activated
carbon for removal of air contaminants from humid air. For activated carbon,
the capacities for hydrocarbons are substantially reduced by humidity (see, for
example, Doong and Yang, 1987). In addition, the resins should be easier to
regenerate in the gas phase than activated carbon. A comprehensive study con-
ducted by Mackenzie et al. (1994) included more than 100 sorbents in examining
the removal efficiencies of humid air contaminated by chlorinated hydrocar-
bons. These sorbents included commercial polymeric resins, carbonaceous resins,
commercial polymers and rubbers, and activated carbon. Based on the removal
efficiency and ease of complete thermal regeneration, Ambersorb XE-563 (a car-
bonaceous resin) and Dowex Optipore were recommended as the best sorbents
(for replacing activated carbon).
Another unique property of the resins is their low capacities for CO 2 (Chen
and Pinto, 1990; Kikkinides and Yang, 1991). Based on this property, combined
with hydrophobicity, removal and recovery of SO 2 and NO x from combustion
gases with resins has been suggested (Kikkinides and Yang, 1991). It should be
noted, however, that basic ion-exchange resins are excellent sorbents for CO 2
(Yoshida et al., 2000).

REFERENCES
Ajayan, P. M. (1999) Chem. Rev. 99, 1787.
Albright, R. L. (1986) React. Poly. 4, 155.
Albright, R. L. and Yarnell, P. A. (1987) Ion exchange polymers. In Encyclopedia of
Polymer Science and Engineering, Vol. 8. Wiley, New York, NY, p. 341.
Alvarez, W. E., Kitiyanan, B., Borgna, A., and Resasco, D. E. (2001) Carbon 39, 547.
Bacon, R. (1960) J. Appl. Phys. 31, 283.
Baes, C. F. and Mesmer, R. E. (1976) The Hydrolysis of Cations. Wiley, New York, NY.
Baird, T., Fryer, J. R., and Grant, B. (1974) Carbon 12, 591.
Baird, T., Fryer, J. R., and Grant, B. (1971) Nature 233, 329.
Baker, R. T. K. and Harris, P. S. (1978) The formation of filamentous carbon. In Chemistry
and Physics of Carbon. (P. L. Walker, Jr. ed.). Dekker, New York, NY, pp. 83–165.
Baksh, M. S., Kikkinides, E. S., and Yang, R. T. (1992) Ind. Eng. Chem. Res. 31, 2181.
Baksh, M. S. A. and Yang, R. T. (1992) AIChE J. 38, 1357.
Barrer, R. M. (1978) Zeolites and Clay Minerals as Sorbent and Molecular Sieves. Aca-
demic Press, New York, NY.
Bartley, G. J. J. and Burch, R. (1985) Appl. Catal. 19, 175.
Bartley, J. J. (1987) Zirconium pillared clays. In Burch, R. loc. cit. p. 233.
Beenakker, J. J. M., Borman, V. D., and Krylov, S. Y. (1995) Chem. Phys. Lett. 232, 379.