Sorbent design

FGD is used to control S02 emissions from coal and oil combustion from electric utilities and industrial sources. Impingement scrubbers are one wet scrubber configuration used to bring exhaust gases into contact with a sorbent designed to remove the S02. On occasion, wet scrubbers have been applied to S02 emissions from processes in the primary non-ferrous metals industries (e.g., copper, lead, and aluminum), but sulfuric acid or elemental sulfur plants are more popular control devices for controlling the high S02 concentrations associated with these processes. 

This chapter discusses the fundamental principles for designing nanoporous adsorbents and recent progress in new sorbent materials. For sorbent design, detail discussion is given on both fundamental interaction forces and the effects of pore size and geometry on adsorption. A summary discussion is made on recent progress on the following types of materials as sorbents activated carbon, activated alumina, silica gel, MCM-41, zeolites, n -complexation sorbents, carbon nano tubes, heteropoly compounds, and pillared clays. 2001 Academic Press. 

Pore size, sorbent design, 87-88 Potential energy, adsorption, 81-83 Precipitation, nanostructured materials,... 

Future needs for a clean environment will lead to increasingly higher standards for air and water pollutants. These challenges require better sorbents that are not conunerciaUy available. Traditionally, sorbents were developed based on empiricism. To meet the new challenges, tailored sorbents need to be developed based on fundamental principles. Theoretical tools, such as ab initio molecular orbital theory and Monte Carlo simulations can be used to speed up the sorbent design. It is one of the goals of this book to help put sorbent design on a more rational basis. 

A major difference exists between bulk separation and purification for sorbent design and selection. For bulk separation, isotherm linearity (hence high-working capacity) is needed. A steep isotherm (or high Henry s constant) is needed for purification. Thus, for r-complexation sorbents, supported salts with monolayer of full-surface coverage are desirable for bulk separation, whereas ion exchanged zeohtes are suitable for purification. 

---