Measures and suggestion for increasing production of ethylene feedstock from refinery

The main influence factors of cracking performance for straight-run naphtha and hydrocracking tail oil were analyzed. Based on imported oil, Mahu oil, Yaha oil prices, as well as naphtha fraction PONA and the simulate cracking product yield, it was not only beneficial to the production of ethylene feedstock, but also to improve the economic benefit of the factory by increasing the blending proportion of imported oil in the refinery, and reducing the blending proportion of Mahu and Yaha oil. After optimizing the processing route of FCC diesel, gasoline and diesel hydrotreating unit will not process FCC diesel, the final point of hydrotreating naphtha was lifted from 190 ℃ to 230 ℃, and it was still a high-quality ethylene feedstock. The hydrocracking catalyst was replaced which effectively reduced BMCI value of tail oil and created conditions for further increase of tail oil production. A new dry gas and low division gas unit was built to realize the effective recovery of light hydrocarbons in the hydrogenated dry gas, low division gas and flare gas in the new refining area, the distillation unit implemented the transformation of shutting down deethane column to simply and efficiently recover C₂⁺ components. Through the measures of increasing the production of ethylene feedstock, the self-sufficiency rate of ethylene feedstock increased by 2.49 percentage points. The C₂⁺ components in FCC and DC dry gas accounts for 67% of the resources to be recovered in the refinery, and ethylene resources are abundant, so it is suggested to give priority to the recovery of FCC and DC dry gas; When the gasoline is surplus, the hydrogenated light naphtha is all used as ethylene feedstock, and when the diesel or kerosene is surplus, the atmospheric first line oil or kerosene is used as ethylene feedstock.