You are operating a batch reactor and the reaction is first-order, liquid-phase, and exoth...

You are operating a batch reactor and the reaction is first-order, liquid-phase, and exothermic. An inert coolant is added to the reaction mixture to control the temperature. The temperature is kept constant by varying the flow rate of the coolant (see Figure P13-5B).

Figure P13-5B Semi-batch reactor with inert coolant stream.

(a) Calculate the flow rate of the coolant 2 h after the start of the reaction. [Ans.: FC = 3.157 lb/s.]

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(b) It is proposed that rather than feeding a coolant to the reactor, a solvent be added that can be easily boiled off, even at moderate temperatures. The solvent has a heat of vaporization of 1000 Btu/lb and initially there are 25 lb-mol of A placed in the tank. The initial volume of solvent and reactant is 300 ft3. Determine the solvent evaporation rate as a function of time. What is the rate at the end of 2 h?

Additional information:

Temperature of reaction: 100°F

Value of k at 100°F: 1.2 × 10−4 s− 1

Temperature of coolant: 80°F

Heat capacity of all components: 0.5 Btu/lb · ° F

Density of all components: 50 lb/ft3

: —25,000 Btu/lb-mol

Initially:

Vessel contains only A (no B or C present)

CA0: 0.5 lb-mol/ft3

Initial volume: 50 ft3