Figure P18.8 shows a CSTR, R-901, carrying out a liquidphase exothermic reaction. The feed, Stream 1, comes from an upstream unit, and its flowrate is known to vary. The heat of reaction is removed by circulating a portion of the contents of the reactor through an external heat exchanger. Cooling water is used as the cooling utility in E-901.

Figure P18.8

For this reactor scheme, devise a system to implement the following control actions:

1. Regulate the temperature of the reactor

2. Regulate the inventory of the reactor, that is, keep a constant liquid level

Explain how your control system would compensate for a change in the flowrate of Stream 1.

What additional control scheme would be needed to maintain a constant conversion in the reactor, assuming that constant conversion can be achieved by ensuring constant residence time in the reactor?

Transcribed Image Text:

Feed R-901 Q P-901 A/B E-901 CW Reactor Effluent