On the Design Flexibility of Atmospheric Crude Fractionation Units

This paper is devoted to study the effect of the design parameters on atmospheric crude distillation units. The following conclusions are obtained: Pump-around circuits play only a role in energy integration, but they have imperceptible effects on the separation goals. Column separation performance is not affected by side-stripper steam rates above a certain threshold, whilst condenser duty is increased unnecessarily. Main steam injection and overflash have important effects on the quality of gas oil. However when the overflash is reduced, the impact on the flowrate of gas-oil produced can be compensated by increasing main column steam injection, [n this way, as the furnace duty is lowered, air emissions can be reduced without altering the column performance. Finally, the usage of reboilers is quantified confirming the recommendations that they should not be used in the design of these systems.