Energy retrofit with simultaneous optimization for a crude fractionation unit

This paper presents the results obtained in the energy retrofit of a Crude Topping Unit. An optimization procedure to explore energy retrofit alternatives that combines changes in operating conditions and pinch analysis is used. Five savings horizons are obtained for the different types of crude studied. In the first stage of the method, a potential savings horizon (maximum possible savings) of approximately $1.5 million dollars per year is identified. A subsequent economic analysis identifies a retrofit opportunity with a payout of 1.2 years. The savings are around $0.7 million dollars (47% of its savings horizon) for this case. Finally, additional savings are identified when the reallocation of the returns of the pump-around circuits is considered. These savings bring down the payout period to 1.1 years. Over a five years horizon, the net revenue (total savings over 5 years - capital expenditure) is in the order of $3.2 millions of dollars.