PFRs. . «■ Plug-flow reactors

Key PFR = Plug Flow Reactor, BSTR = Batch Stirred-Tank Reactor, (S)BSTR = (Semi)Batch Stirred -Tank Reactor, SBSTR = Semibatch Stirred-Tank Reactor, CSTR = Continuous Stirred-Tank Reactor, TBR = Trickle-Bed Reactor. 

Abbreviations CSTR, continuous stirred-tank reactor EIM, environmental impact minimization NP, non-products PEI, potential environmental impact PFR, plug-flow reactor... 

In the figure, a link type called PFRLink is defined. This example link type expresses that exactly one instance of the specific reactor type PFR (plug flow reactor) can be simulated by exactly one instance of the specific reactor block RPlug in the simulation model. The reactors in both documents can have an arbitrary number of ports which are mapped by the link as well. To assign corresponding ports, the link may have sublinks each mapping pairs of ports . Both reactors are referenced as dominant increments. This link type is rather specific, as it forms relatively tight constraints for all of its instances. 

Ideal tubular reactor or batch stirred tank (PFR plug flow reactor or STR stirred tank reactor)... 

Figure 19.5 Speciation plots for the competitive-consecutive second-order reactions of ammonia and ethylene oxide. Panel PFR plug flow reactor panel CSTR individual continuous flow stirred-tank reactor.

Tubular reactor The contact time is the same for all molecules or fluid elements along the reactor when the velocity is uniform in the cross section of the tube, satisfying the plug flow. All molecules have the same velocity. Therefore, the concentration is uniform in a cross section of the tube and varies only along the reactor. In the isothermal case, the temperature remains constant in the longitudinal and radial directions. In the nonisothermal case, the temperature varies along the reactor. This reactor will be denominated ideal PFR (plug flow reactor). 

For the first criterion, one compares the reactor volumes based on the average residence time for a given extent of reaction or final conversion. The average residence time depends on the reaction kinetics and therefore the reaction rate, which in turn depends on whether the reaction takes place at constant volume or variable volume. In a system at constant volume, one obtains directly a ratio between the volumes, because the average residence time is equal to space time which is defined as the ratio between reactor volume and inlet volumetric flow in the reactor. For the same conversion, the ratio between volumes is proportional. Since the average residence time in a PFR reactor is similar to the reaction time in a batch reactor, we may assume that they have similar behaviors and then we compare only the ideal tubular reactors (PFR — plug flow reactor) to the ideal tank reactors (CSTR—continuous stirred-tank reactor). 

In a PFR (plug flow reactor), the polymer composition can be found by integration of the incremental addition to the polymer across the length of the reactor. During the progression of the monomers in a PFR, the composition varies with conversion ... 

GPPS general purpose polystyrene PFR plug flow reactor NR not relevant ... 

Fig. U7 Definition sketch showing e amm modes of operation for reactors, (a) Simple batch reactor, (b) Single-pass reactor, (c) tetcb-mlfEylatioii reactor, (d) Cascade of n identical reactors, PFR, plug flow reactor CSTR. oootuiiowl r stirred tank reactor.

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