Abstract
Crude fractionation units are designed to separate the crude in several product streams (naphtha, gas oil, diesel, etc.). Crude fractionation is a highly energy intensive process and represented one of the most important areas for energy integration in a refinery by modifying the existing plants and generating improved designs. Important heat exchange also takes place, and the energy efficiency is related to the column design parameters. First, the optimal condenser and pump-around duties were determined for three types of crudes; light, intermediate, and heavy crudes with using the heat demand-supply diagram, an important tool for modification. These crudes constitute the targets for the design of a multipurpose heat exchanger network. The multipurpose design problem for which several alternative solutions of similar cost exist. Such property is suspected to be true for the retrofit case, that is several retrofit scenarios aimed at improving energy efficiency and/or throughput can exist and be competitive. The result was observed that when the optimal condenser and pump-around duties were located in these designs, the energy consumption and operating costs were reduced.
