b) In any refineries, the production amount of refining products (petrol, kerosene, diesel, and bottom residues) varies depending on crude oil processing rate and the type of crude oil being processed. To maintain the production amount of each product in January 2022, Sianyang Refinery plans their production capacity based on processing a total rate of 100 kilo barrels per day (KBD) of crude oil mixture containing 70 vol% of Tapis and the balance is Kikeh. Kikeh is fed from Tank 1 while Tapis is fed from Tank 2. The two separate flows of the crude oils are mixed in the pipeline before the crude oil mixture enters the crude distillation unit (CDU). A sketch of the process block diagram is shown in Figure 5. Tank 1 XD Kikeh CDU Tank 2 Tapis XD Figure 5 Process block diagram of crude oil feed to distillation unit. i) ii) To ensure that the production amount of each product is maintained as per plan in January 2022, recommend two control objectives in the process. (2 marks) Design P&ID of a suitable integrated control loops system for the CDU feed strategy to simultaneously achieve the two control objectives identified in (i) by applying the following rules: Cascade control: The flowrate of Kikeh is manipulated based on its concentration in the total crude mixture feed to CDU. Ratio control using multiplier scheme: The flowrate of Tapis is manipulated based on the desired crude mix composition. Label the setpoint in each control loop