$4$Y$9.$ Ponchon$-$Savarit $($Prob$.13-3$ in Luyben, Chemical Process Analysis$)$

The column of the preceding problem was designed $20$ years ago and has been operating ever since. Energy costs have risen, and it is now desired to reduce operating costs. One suggestion is to heat the feed to $200F$ using waste heat, thus, perhaps, operating at a lower reflux ratio and reducing the reboiler duty. Can this be done? Will we have to change the column feed point? What will be the new reboiler heat duty?