Combined process of hydrotreating and catalytic cracking of hydrocarbon oils

摘要

Disclosed is a combination process for improved hydrotreating and catalytic cracking of hydrocarbon oils, including: contacting residual oil, catalytic cracking cycle oil, and optional distillate oil with a hydrotreating catalyst under hydrotreating conditions in the presence of hydrogen followed by separation of the reaction products to obtain hydrogenated tail oil and other products; contacting the hydrogenated tail oil and optional normal catalytic cracking feedstock oil with a cracking catalyst under catalytic cracking conditions followed by separation of the reaction products; wherein the hydrogenated tail oil and/or normal catalytic cracking feedstock oil are separated into at least two fractions prior to contacting the hydrogenated tail oil and/or normal catalytic cracking feedstock oil with the cracking catalyst.

主权项

1. An improved combined method of hydrotreating and catalytic cracking of hydrocarbon oil, comprising:
contacting residual oil, catalytic cracking cycle oil, and optional distillate oil with a hydrotreating catalyst under hydrotreating conditions in the presence of hydrogen followed by separation of the reaction products to obtain gas, hydrogenated naphtha, hydrogenated diesel oil, and hydrogenated tail oil; contacting the hydrogenated tail oil and normal catalytic cracking feedstock oil with a catalytic cracking catalyst under catalytic cracking conditions followed by separation of the reaction products to obtain dry gas, liquefied petroleum gas, catalytically cracked gasoline, catalytically cracked diesel oil, and catalytic cracking cycle oil; wherein the catalytic cracking cycle oil comprises less than 30 wtppm of solid particles, and the size of the solid particles being less than 10 μm; the contact reaction with the cracking catalyst is carried out in a reactor having at least two reaction zones I and II along the flow direction of reactants; prior to contacting the hydrogenated tail oil and the normal catalytic cracking feedstock oil with the cracking catalyst, at least a portion of the normal catalytic cracking feedstock oil is separated into normal catalytic cracking heavy feedstock oil and normal catalytic cracking light feedstock oil, and the hydrogenated tail oil is optionally separated into at least two fractions, the light and the heavy fractions of the hydrogenated tail oil, wherein the normal catalytic cracking heavy feedstock oil and the optionally separated heavy fraction of the hydrogenated tail oil have a boiling point above 500° C., and the normal catalytic cracking light feedstock oil and the optionally separated light fraction of the hydrogenated tail oil have a distillation range of 350˜500° C., wherein the contact reaction with the cracking catalyst comprises: (i) charging the reaction zone I with one of normal catalytic cracking heavy feedstock oil and normal catalytic cracking light feedstock oil, optionally with unseparated normal catalytic cracking feedstock oil; whereas charging the reaction zone II with the other of normal catalytic cracking heavy feedstock oil and normal catalytic cracking light feedstock oil, optionally with unseparated normal catalytic cracking feedstock oil, and (ii) prior to the contact reaction, combining at least one of the normal catalytic cracking heavy feedstock oil and the normal catalytic cracking light feedstock oil with at least one feed chosen from unseparated hydrogenated tail oil, the light fraction of the hydrogenated tail, and the heavy fraction of the hydrogenated tail oil.