A gas absorption process is shown below to remove CO2, consisting of an inlet separator, an amine contactor and a flash tank. An amine solution absorbs the CO2 in the contactor, becoming more rich in CO2 along the column through a chemical reaction forming carbamate as a product. Design a control system for the conditions given below. In each case (i) identify the control variable, the measured variable, the manipulated variable and the possible disturbance variables, and (ii) provide sketches of the control arrangement suitable for a PCD. You should show the main control loops and the main hardware elements in them; you do not need to show trips and alarms, isolation valves or piping details. Use a different drawing for (a) and (b), showing the particular control loop relevant to that question. The conditions to be controlled are: (a) The CO2 concentration in the Sweet gas to pipeline / LNG plant feed. (b) The relative humidity of the gas exiting at the top of the inlet separator. Sweet gas to pipeline / LNG plant feed 50 - 70 bar Lean Amine 40C Amine contactor Flash gas Sour feed gas 6 bar Inlet separator Flash tank I Rich amine Water, C2+ hydrocarbons