Additional Homework Problems

CDGA 6-1A

Pure butanol is to be fed into a semibatch reactor containing pure ethyl acetate to produce butyl acetate and ethanol. The reaction

is elementary and reversible. The reaction is carried out isothermally at 300 K. At this temperature the equilibrium constant is 1.08 and the specific reaction rate is 9 X 10-5 dm3/mol/s.Initially, there is 200 dm3of ethyl acetate in the vat and butanol is fed at a rate of 0.05 dm3/s. The feed and initial concentrations of butanol and ethyl acetate are 10.93 mol/dm3 and 7.72 mol/dm3, respectively.

  1. Plot the equilibrium conversion of ethyl acetate as a function of time.

  2. Plot the conversion of ethyl acetate, the rate of reaction, and the concentration of butanol as a function of time.

  3. Repeat parts (a) and (b) for different values of the butanol feed rate and the amount of ethyl acetate in the vat.

  4. Rework part (b) assuming that ethanol evaporates (reactive distillation) as soon as it forms.

  5. Use Polymath or some other ODE solver to learn the sensitivity of conversion to various combinations of parameters.

  6. Discuss what you learned from this problem and what you believe to be the point of this problem.

[3rd Ed. P4-26]