- We want to produce ammonia from nitrogen and hydrogen in a gas phase reactor where the temperature is maintained constant by a coolant in a jacket around the reactor. - 1) Draw the process - 2) What are the possible disturbances? - 3) Draw the process control loop assuming that the controller is digital and the control valve is pneumatic. We need converters. - 4) Show the elements of the FOUR steps of the control loop in a block diagram including input and output variables