Devise a control system for the distillation column described in Chapter 11, Example 11.2 The flow to the column comes from a storage tank. The product, acetone, is sent to storage and the waste to an effluent pond. It is essential that the specifications on product and waste quality are met.

Data from example 11.2

Acetone is to be recovered from an aqueous waste stream by continuous distillation. The feed contains 10 mol% acetone. Acetone of at least 95 mol% purity is wanted, and the aqueous effluent must not contain more than 1 mol% acetone. The feed will be a saturated liquid. Estimate the number of ideal stages required.

 

y (mol fraction acetone) 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0 2 0 XB LOL 3 q-line Equilibrium line UOL,Rmin 0.2 0.4 0.6 x (mol fraction acetone) UOL 678910 0.8 XD 1