Reactor-separator system

A coupled reactor-separation system (Figure 4.6) was used by Livingston et al. in which they were able to perform a Heck reaction and to recycle the catalyst 10 times using a semi batch method. [14,15] To prevent degradation of the membrane by the... 

Fig. 13.1 Two basic types of integrated reactor—separator systems. In A the membrane is used as an add-on to the reactor, whereas in B the membrane is fully integrated.

In addition to recycling reactants back into the reactor, there are several other tricks to keep reactants in the reactor and thus attain higher conversions and yields. Aunong these are formation of vapor-phase products from liquid or solid feeds and the use of membranes that pass products but retain reactants. We will discuss the integration of reactor-separation systems in Chapter 12. 

L. Pibouleau, P. Floquet, and S. Domenech. Optimal synthesis of reactor separator systems by nonlinear programming method. AlChEJ., 34 163,1988. 

Ismail RS, Pistikopoulos EN, Papalexandri KP. Synthesis of combined reactive and reactor/separation systems utilizing a mass/heat exchange transfer module. Chem Eng Sci 1999 54 2721-2729. 

Finally, we consider a preliminary approach for the optimal synthesis of reactor-separation systems. Here, we formulate a combined reaction-separation model by postulating a species-dependent residence time distribution. The optimization of this distribution function leads to a separation profile as a function of time along the reactor. The costs for maintaining a separation profile are handled through a separation index, which models the intensity of separation,... 

Pibouleau. L., Floquet, P., and Domenech, S. "Optimal Synthesis of Reactor Separator Systems by Nonlinear Programming Method, AIChE J. 34, 163 (1988). 

FIGURE I l.l I Production of urea by a simple, one-pass reactor-separator system,... 

An LM enzyme system, which can combine reaction and separation as well as maintain a concentration gradient between internal and external aqueous phases, is thus being investigated for the L-tyrosine to L-DOPA conversion reaction. This combined enzyme reactor / separation system... 

CSTR equivalence prindple. Example 4.8 is motivated by a recent result of Feinberg and Ellison called the CSTR equivalence principle of reactor-separator systems [4]. This surprising principle states ... 

M. Feinberg and P. EUison. General kinetic bounds on productivity and selectivity in reactor-separator systems of arbitrary design I. Principles. Ind. Eng. Chem. Res., 40fl4) 3181-3194, 2001. 

For w -order reaction A -> products taking place in an isothermal CSTR-Reactor-Separator system, the dimensionless model Eqs. 13.7 and 13.10 reduces to ... 

Marty et al. have reported a complete pilot-plant reactor/separator system for carrying out enzymatic reactions in SCFs. The plant comprises a continuously operated tubular reaction vessel followed by four cyclone separators. The separators may be put in descending pressure order by adjusting needle valves between each vessel. Liquid products are recovered from the bottom of each vessel discontinuously [15]. 

V decreases with increasing conversion of A. Thus, if it is possible to remove small amounts of V cheaply from large volumes of the reaction mixture, the optimum reactor configuration and mode of operation would involve the use of a plug flow reactor with low conversions of A per pass coupled with a separator to remove the product V and to recycle unconverted reactants. The exact conversion level to be employed will depend on an economic analysis of the combined reactor-separator system. 

Reactor with recycle [4]. The system depicted in Fig. 8.7 shows a simplified scheme of a reactor-separator system that includes a recycle stream. Compounds A and B are fed to the reactor to produce compoimd C according to the following stoichiometric reaction ... 

Fig. 1. Reactor-separator system with recycle of unconverted reactant.

Table 1. Design data for reactor-separator system.

Fig. 2. Scaled disturbance sensitivity of reactor-separator system. Effect of changes in reaction rate constant on distillate composition A magnitude larger than 1 at a particular frequency...

Fig. 3. Scaled frequency response from reflux L to distillate composition yo of reactor-separator system.

Fig. 9. Reactor-separator system. Process sensitivity function 5p before (dashed) and after (solid) addition of delay tank in recycle path.

Fig. 10. Filter effect of delay tank in recycle path (solid) and cascaded mixing tank of same size (dashed) for reactor-separator system.

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