Patent ID: 10774276

Abstract:
A stream of cracked naphtha is fractionated into at least four specified fractions defined by their respective boiling point ranges. The lightest fraction, IBP to 50° C., is treated in a selective etherification or alkylation process to reduce its RVP value and increase its RON. The second fraction, 50° C. to 150° C., is selectively hydrogenated to treat and convert the diolefins present and the treated stream is sent directly to the gasoline blending pool since it has the desired RON and low sulfur content. The third, and optionally a fourth fraction, boiling in the range of 50° C. to 180° C., in an embodiment, are utilized for the production of aromatics and the raffinate stream, after aromatic extraction, is sent to the gasoline blending pool. A fraction of this latter stream can optionally be recycled for further cracking to produce additional aromatics and gasoline blending components. The heaviest fraction, 180° C. to MBP, constitutes a relatively small volume and is hydrotreated at high pressure, and one portion of the hydrotreated stream is recycled to the FCC unit for further processing and the remaining hydrotreated portion is sent to the gasoline blending pool.