The product from a reactor contains 60% w/w A, 25% w/w B and 15% w/w C. The final saleable product is required to contain 90% A.

The mixture can be purified in a distillation column but under the conditions possible in the column the product produced is 100% A with the bottom product containing no A. It is possible to mix the reactor products and distillation product.

Calculate:

(i) The amount of reactor product that could by-pass the distillation system to give the maximum amount of saleable product at minimum cost

(ii) The amount and composition of ‘waste’ material.