Using a minimum approach temperature of $20\backslash$deg C:

a$.$ Construct a temperature interval diagram.

b$.$ Construct a cascade diagram and determine the pinch temperatures and hot and

cold utilities.

c$.$ Determine the minimum number of heat exchangers required.

d$.$ Design a heat exchanger network above the pinch.

e$.$ Design a heat exchanger network below the pinch that utilizes only one utility exchange