Discontinuous recycle reactor

Figure 6.57. Summary diagram of work flow in the systematic development of a bioprocess of the presented integrating strategy. The diagram is based on the interaction between kinetics (Chap. 5) and transport (Chap. 3) processes, which are clarified during a kinetic analysis (Chap. 4). As a special situation, the design and utilization of new types of reactors are shown (discontinuous stirred vessel, DCSTR bubble column, BC semicontinuous stirred vessel, SCSTR recycle reactor, RR continuous stirred vessel, CSTR continuous cascade, NCSTR tower reactor, TR continuous plug flow reactor, CPFR fixed and fluidized bed reactor, FBR).

The system can be operated in the parallel mode, discontinuously (batch-wise) with each reactor as an independent unit, semi-continuously or as a reactor cascade. Both homogeneous and heterogeneous reactions as well as product and catalyst separation and catalyst recycling are possible. 

Commercial application of Cu-catalyzed oxydecarboxylation of benzoic acid was initiated in the 1960s by Dow Canada. At least three different companies operated similar processes before they were discontinued in recent years [3c]. The process uses toluene as a feedstock and consists of two main reactors (Figure 5.2) [3a]. Toluene is oxidized in the first reactor to approximately 40% conversion and 90% selectivity for benzoic acid. Toluene is recycled and intermediate benzaldehyde is isolated or recycled. Benzyl benzoate, methylbiphenyls, formic acid, and acetic... 

Discontinuously operated trickle-bed reactor with recycle, 1 inch diameter... 

Commercially, solution polymerizations are not carried out to high conversions (near 100%) but continuously at a constant monomer concentration. The unreacted and evaporated monomer is recycled together with the solvent. This type of production process has two advantages. The reactor always works in a range of high polymerization rates, and the molecular weight distribution curve is not so broad as it is with polymers produced in a discontinuous process with high conversions. 

In evaluating the residence time distributions in a continuous system oper> ating without recycling, for the case of the ideal discontinuous stirred vessel the curve with an exponential decay of the dilution process normally appears. But it appears in such a way that the pulse functions do not overlap (see Fig. 3.6 and also Blenke, 1979). This means that mixing and dilution processes are superimposed, and that in reactors that deviate from the ideal continuous... 

The ALMR program was funded from 1984 to 1994. Two products emerged the advanced conceptual PRISM reactor design and the proliferation resistant pyroprocess for spent fuel recycling. Following the discontinuation of DOE s ALMR program, GE continued to develop PRISM. 

Flaring of discontinuous emissions from reactors is considered BAT if these emissions cannot be recycled back into the process or used as fuel (see BAT 7 above). 

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