1. Step Change Cut off 40% in Reflux Percent. Delta M = 40%

2. Step Change Analysis

3. Delta C = 23.7oC

4. Step Change Analysis Delta C = 23.7oC t o = 0.28 min

5. Step Change Analysis Delta C = 23.7oC t o = 0.28 min 0.632deltaC

6. Step Change Analysis Delta C = 23.7oC t o = 0.28 min 0.632deltaC t 2 = 2.94 min

7. X,Y vs T diagram for methanol-water T 50% Reflux T 99.9% Reflux

8. X,Y vs T diagram for methanol-water slope=-109 Slope=-16 X = 0.0585

9. Step Change Parameters t o = 0.28 min K = (0.0585/40) = 0.00146 composition/% Tau = t o – t 2 = 0.66 min EBc = EBt/m = 0.2828/62.5 = 0.00452