This document discusses when and why advanced control techniques beyond single-loop PID control may be needed. It describes economic incentive, safety/compliance, and equipment protection as key objectives that can require reduced variability. Multi-loop techniques like feedforward, cascade, and override control are introduced to improve control in cases where single PID loops are insufficient. Model predictive control is also presented as an option for addressing difficult dynamics or process interactions. Examples of ammonia plants, spray dryers, and batch reactors are provided.

1. Maximizing the Return on Your Control Investment Part 2 of 2 Meet the Experts Sessions

9. Example – Ammonia Plant

10. Example – Impact of Synthesis Bed Temperature

12. Example – Impact of Loop Pressure

15. Utilize Process Capacity to Absorb Variability

17. Utilize Process Capacity to Absorb Variability Level Manipulated Variable Before Level Manipulated Variable After

21. Example – Steam Heater

38. Example - Batch Chemical Reactor

40. MPC Control of a Batch Reactor