Optimize design for heavy crude

Addition of atmospheric residuum hydrotreating with fluid catalytic cracking or delayed coking appear to be most attractive for converting a typical light crude refinery to heavy crude operation. Examination of seven alternative approaches for accomplishing this conversion shows a range in economic results that illustrate the general conclusions but require specific examination for each refinery to determine its optimum choice. During 1978-1982, many refiners initiated projects to permit processing lower quality heavier crudes with the capability for converting residuum to transportation fuel products. A substantial price differential between light and heavy crude and a low residual fuel oil value provided a twofold incentive for these projects. Recently, crude price differentials have shrunk, and high-sulfur residual fuel oil values have risen almost to crude prices. Some analysts believe that this is a temporary market situation and that incentives will be restored within five years as heavy crudes become more available and outlets for high-sulfur fuel oil become more limited. Various processing schemes are possible for use in converting a typical light crude refinery. Several of these are considered in a screening evaluation.