Ion exchange is a stoichiometric phenomenon commonly used in water treatment as an end-of-pipe technique. Such process is highly influenced by mass transfer conditions and may be modeled by adsorption equations. Although widely applied in industries its theory has not been completely understood and depends on the exchanger characteristics. Moreover, competitive systems may add complexity and decrease removal efficiency and exchanger selectivity mainly in dynamic systems. In this chapter some general theory was presented and some detailed examples involving alginate biopolymer, bonechar and zeolite in single and competitive systems were discussed in batch and continuous state.
Part of the book: Mass Transfer
Due to the constant expansion of the aviation sector, the global air industry has performed the search for alternative fuels to petroleum‐derived aviation kerosene, which present low emission of greenhouse gases and other pollutants, in addition to supplying the engines and aircraft already in operation using the existing distribution infrastructure. Thus, one alternative that has been studied is the synthetic kerosene derived from gasification processes followed by Fischer‐Tropsch synthesis. Several features seem to be crucial in controlling product selectivity in the aviation fuel range, among them are the zeolitic support, acidity, and promoters. Therefore, the effect of these parameters in the Fischer‐Tropsch synthesis is discussed in this chapter and, finally, the zeolitic catalysts that, according to the literature, have significant potential in obtaining synthetic aviation fuel are evidenced.
Part of the book: Zeolites