A stirred tank reactor9 is a tank equipped with a large stirring device that is used in the chemical and biochemical industry to produce chemical reactions. A series of 5 such tanks will be used to lower the concentration of toxic chemical from c0 at input for tank 1, to no more that cQ on exit from tank 5. A flow rate of q liters per minute will be maintained through the tank sequence, but the effect of each tank depends on its volume vi.

In particular, the units of toxic chemical removed per minute will be approximately g

output concentration 1 + output concentration times the tank volume. Stirred tank cost can also be estimated from the volume at a1volume2b.

Formulate an NLP model to find a minimum total cost sequence of tanks using the decision variables 1i = 1,

c, 52 ci ! output concentration of tank i vi ! size of tank i Assume that all other symbols are constants.