Control of Crude Fractionator Product Qualities During Feedstock Changes by Use of a Simplified Heat Balance

This paper describes a technique which applies a heat balance around the crude fractionator to predict changes in the feedstock volatility. Volatility changes are then fed forward to the sidestream yield controllers, significantly improving sidestream quality control during the several hours following feedstock switches. The application was tested at one of Exxon affiliated refineries with good results.