Answer Happy

We like to regulate the composition of distillate, xp, and bottom products, IB from a distillation column, using the reflux flow R and vapor flow in the column V (or equivalently the steam flow rate) as manipulated variables. The following input-output relationships for the distillation column have been determined experimentally. 0.60e-1.15 0.5e-1.05 Xp (s) R(8) (5s + 1) (2s + 1) V (s) 6s + 1) (3s +1) -1.35 0.5e -1.0s 0.30e IB (8) (58 +1)(8 + 1) R (3) V (s) (5s + 1)(8 +1) a) Select the pairings between controlled outputs and manipulated inputs so that the resulting loops offer minimum steady-state interaction. b) If the best couplings still possess significant interaction between the control loops, design two decouplers that produce two non-interacting control loops. c) Tune two feedback PI controllers for the pairs you have determined in part (a) d) Show the set-point tracking performance of your design by introducing step input change of magnitude 0.1 for (i) distillate composition and (ii) bottom products composition.