Anywhere compressed air can be eliminated represents an opportunity to reduce system operating expenses. Often, this reduction means fewer compressors must operate to meet the plant's air requirements.
Christopher Schmidt, Mark D'Antonio and Alan MacDougall
Electric motors in continuous or near-continuous service have high energy costs, even at the relatively low electric rates common in much of the chemical industry. Don't squander savings opportunities when considering motor replacement
Install a flow meter in the recycle, cascade the flow set point with a pressure control loop. With proper tuning, the valve characteristics are lost in the flow control loop, which should be tuned fast with PI.