Performance Evaluation of Unconventional Index for Controllability and Stability Analysis: Application on a Patented Reactor for Renewable Hydrogen Production

Abstract

In a decentralised PID control, improper input-output pairings would reduce plant safety, productivity, and profitability. When designing a process control system, controllability evaluation is crucial since it helps to pinpoint the best input-output combinations. Current conventional indices, however, are unable to determine the highest possible closed-loop efficiency. Using MATLAB software, this study proposes an innovative index to simultaneously find control pairings and maximum control performance. The index, namely Loop Gain Controllability (LGC) index was evaluated on a distillation process and integrating tank before being used to study a patented industrial-scale reactor's controllability and stability. The LGC index provided values of 1.39, 1.45, 1.40, and 1.08 for four reactor schemes when applied to a decomposition reactor for hydrogen production, while RGA and NI proposed values of 1 for the first three schemes (direct pairing) and negative for the fourth plan (inverse pairing). The closed-loop control response of reactor scheme 2 (P2), which demonstrated that it was controllable and stable when simulated, proved the hypothesis that the larger the LGC value would lead to higher controllability and stability. This demonstrates that LGC