Suggest a modification of the Direct Synthesis approach that will allow it to be applied to open-loop unstable processes. (Hint: First stabilize the process using a proportional-only feedback controller.) Draw a block diagram for your proposed control scheme.
ChE 20500 Hour Exam 2: Spring 2015, April 1, 2015 (8:00p – 9:30p) Problem 1.(35 points total) A large refrigeration laboratory houses biological samples at colder temperatures in order to prevent degradation of the samples. Researchers work inside of this room for given periods of time despite the relatively cold temperatures. Air for this laboratory is supplied from the exterior of the building. This wet air is slightly pressured at an absolute pressure of 805 mm Hg. The moist air is at a temperature of 37 °C and a relative humidity of 42.1%. This stream is partially dehydrated (i.e., some water is removed from the air and leaves the process) in a cooling unit. After going through the cooling unit, this stream (which still contains some moisture in the air) enters