1) Repeat the calculations for a constant column pressure of 1atm.
   That is, with reboiler pressure = 1 atm.
   Do you see major changes in the results?

2) Simulate the distillation column at a constant pressure of 1atm.
   That is, the reboiler pressure also is at 1atm.
   If the reflux ratio is increased beyond 2, does the purity improve?
   What reflux ratio should you use, if the actual purity is as desired.
   In a future tutorial, we will show how sensitivity analysis can help do this

3) Simulate the column at reflux ratio = 2.
   Keep the column pressure constant at 1atm.
   Increase the number of trays by 1.
   As the number of trays has changed,you have to use the interpolate option.
   This was mentioned earlier also.
   With a larger number of trays, has the purity increased?

4) Verify the following relationship:
   Composition of vapour flow to the condenser = distillate product composition
   Explain why this equation has to be satisfied.

5) Check the consistency of compositions,temperature and pressure at the reboiler.
   Do this through an equivalent flash calculation.

6) Solve the distillation column by different solution methods
   Compare the answers 
   Compare the computation times