**5. Conclusion**

660 Mass Transfer - Advanced Aspects

0 500 1000 1500 2000 2500 3000 **Time (min)**

0 500 1000 1500 2000 2500 3000 **Time (min)**

0

0

2

4

6

8

**C (ppm)**

10

12

14

16

Fig. 12. Theoretical elution curves at raffinate port: Run 2

Fig. 13. Theoretical elution curves at extract port: Run 2

Tr21 Tr18 Taxol

5

10

15

20

25

**C (ppm)**

30

35

40

45

Tr21 Tr18 Taxol

50

This chapter showed that a multicomponent and complex system, such as taxane mixture, can be treated as a pseudo-binary model, in which mixtures A (low-affinity mixture) and B (high-affinity mixture) are considered as single solutes A and B. In this case, it is possible to use the standing wave design to specify zone flow rates and switching time. The numerical simulation of SMB offers predictive results, pointing to two separation steps of Taxol® from impurities at least. It was analyzed the influence of column numbers in Taxol® separation, in which purity improvement was not relevant with number-ofcolumn increase (4 to 8). In this case, the purity increase is governed by the selectivity between Taxol® and other solute.
