Process Engineering and Reactor Concepts

This concept was demonstrated at the Institute of Process Engineering and Cryogenics at ETH (Switzerland) during the last two years with the FilmCooled Hydrothermal Burner (FCHB). The FCHB operated at pressures of 25 MPa and temperatures up to 2000 K, cf. [1], Experiments and detailed analysis led to the basic design approach for SCWO reactors discussed herein which is based on wall boundary layer control and internal recirculation. 

Before leaving this section we consider a slightly different optimization problem that may also be expensive to solve. In flowsheet optimization, the process simulator is based almost entirely on equilibrium concepts. Separation units are described by equilibrium stage models, and reactors are frequently represented by fixed conversion or equilibrium models. More complex reactor models usually need to be developed and added to the simulator by the engineer. Here the modular nature of the simulator requires the reactor model to be solved for every flowsheet pass, a potentially expensive calculation. For simulation, if the reactor is relatively insensitive to the flowsheet, a simpler model can often be substituted. For process optimization, a simpler, insensitive model will necessarily lead to suboptimal (or even infeasible) results. The reactor and flowsheet models must therefore be considered simultaneously in the optimization. 

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