7. A column separating propane/propylene is depicted as the figure below. Which of the following statement is wrong? (a) The azeotrope formed by propane/propylene leads to the large amount of trays (NT=195) required for separation. (b) Incorporating the vapor recompression cycle to this column potentially provides the improvement. (c) The reason for operating this column at 18 bar is to enable the use of the less expensive cooling/heating medium at the condenser/reboiler. (d) In practice, the space issue for this column is more problematic than the issue of operating cost