Optimal Design of Heat Exchanger Network in Oil Refineries

The performance of the heat exchanger network (HEN) in a plant is an important aspect of energy conservation. Pinch technology and mathematical programming techniques offer an effective and practical method for designing the HEN for new and retrofit projects. The fluid catalytic cracking (FCC) is a dominant process in oil refineries and there has been a sustained effort to improve the efficiency and yield of the unit over the years. HEN optimal design in FCC process is an essential element in reducing the cost and improving the process as a whole. The objective of this work is to introduce a systematic procedure for designing optimal and flexible FCC-HEN that incorporates variations in feed flowrates and specs, and on same time considers different schedules imposed on the process. First, a hierarchical approach consisting of a general optimization formulation that is accounting for the anticipated schedules and heat integration during the FCC-HEN design phase will be used in this project. Then, a new targeting approach will be introduced because of the complexity of the formulation for heat integration with varying flows and temperatures. Finally In order to synthesize a flexible configuration of the FCC-HEN, a multiperiod formulation will be developed and applied on FCC process to account for the variations associated with the anticipated operational schedules.