The relative exergy destroyed: A new tool for process design and control

Due to increasing energy demands and strict environmental regulations, the eco-efficiency of all industrial processes has become vitally important. Control system structure determination is a vitally important activity in process control and a poorly structured control strategy can lose a lot of energy in the process/plant. To save this energy, engineers need to find a way to integrate control loop configuration and measurements of eco-efficiency. In this paper, we present the relative exergy destroyed array (REDA), a new tool to measure the relative eco-efficiency of a process. Although based on steady state information, REDA still provides valuable information by comparing the eco-efficiencies of a process with several process control structures. The results obtained from the REDA are interpreted and explained with the help of two case studies. REDA can help guide the process designer to find a quick optimal control design with low operating cost/eco-efficiency.