Eco-efficiency and control loop configuration for recycle systems

Given that the eco-efficiency of industrial processes/plants has become important, engineers need to find a way to integrate control loop configuration and measurements of eco-efficiency. The exergy eco-efficiency factor, a new measure of eco-efficiency for control loop configuration has been developed. The exergy eco-efficiency factor is based on the thermodynamic concept of exergy which can be used to analyze a process in terms of its efficiency. The combination of the Relative Gain Array (RGA), NI, CN, dynamic RGA, Relative exergy gain array (REA) and the exergy efficiency factor will help guide the process designer to find the optimal control design with low operating cost/eco-efficiency. In this paper, we validate the proposed eco-efficiency factor for the common industrial situation involving recycle streams.