I'm having trouble trying to figure this out. I am aware how to employ overall efficiencies on McCabe-Thiele - IIRC it goes like: "draw a pseudoequilibrium curve in between the equilibrium line, and the rectifying/stripping lines - 100% efficiency means that it coincides with the equlibrium line, 50% efficiency means it lies directly in between the EL and RL/SL, and 0% efficiency means that the pseudoequilibrium line concides with the RL/SL" I don't know how to employ efficiencies on the Ponchon-Savarit though. Do I still do this mechanic with the diagonal line? What about the enthalpy curves? is there a basic step-by-step guide in doing this? Thanks!