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Figure 13.6 Temperature control responses for + 20% production rate changes for (a) MeAc, (b) EtAc, (c) IPAc, (d), BuAc, and (e) AmAc systems.

flowsheets, faster responses and much more symmetrical responses can be obtained for the controlled temperatures as well as major product compositions as shown in Figures 13.6b and 13.6c. The product composition settles in <10 h and much smaller offsets in the acetate composition can be achieved (^0.001 mf for EtAc, nil for IPAc). For the type III flowsheets, symmetrical responses in the temperature control trays can be seen in Figures 13.6d and 13.6e. However, two different composition dynamics are observed, which can

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Figure 13.6 (Continued).

Figure 13.6 (Continued).

be foreseen from nonlinear analysis (Table 13.1). For the BuAc system, the product composition dynamics settles in <5 h (the fastest response) and symmetrical responses can also been seen for most of the process variables except the trace acid concentration (Fig. 13.6d). Steady-state offsets are also observed, but the error is around 0.002 mf for +20% feedflow changes. For the AmAc system the dynamics are fast, but the responses are asymmetrical

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