Several catalytic cracking patents

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Reduction of sulfur content in fluidized catalytic cracking gasoline / = US 6103105- A. HALDOR TOPSOE AS. First, fractional distillation is carried out; the heaviest fractions are hydrogenated to remove sulfur. The resulting streams and the intermediate fractions are quenched rapidly and then hydrogenated, which reduces the sulfur content while minimizing losses in octane rating. To reduce the sulfur content in FCC gasoline, the following methods are employed: ① Fractionation into light fractions containing 50%–80% FCC gasoline, intermediate fractions containing 10%–30% FCC gasoline, and heavy fractions containing 5%–20% FCC gasoline; ② Hydrorefining of the heaviest fractions in the first bed of the hydrorefining unit to remove sulfur; ③ Quenching of the effluent from the first bed and the intermediate fractions; ④ Hydrorefining of the combined stream obtained in step ③ in the second bed of the hydrorefining unit to ensure the removal of total sulfur. Used to reduce the sulfur content in FCC gasoline. The desired sulfur content can be achieved while appropriately reducing the olefin content, with minimal loss in octane number. A FCC process for increasing the production of light olefins including propylene is described in WO200040672 - A1 by EXXON RES & ENG CO. This process makes effective use of a large-pore zeolite cracking catalyst along with a medium-pore zeolite catalytic component; it increases the yield of C3 olefin products. The process involves: ① The FCC feedstock comes into contact with a high-temperature regenerated catalyst containing both large-pore and medium-pore zeolite components in the first cracking stage, where the feedstock undergoes catalytic cracking under reaction conditions to produce low-boiling-point hydrocarbons such as naphtha, light olefins including propylene, as well as a catalyst slurry containing vaporizable hydrocarbons and coke; ② The low-boiling-point hydrocarbons are separated in a separation stage, while the hydrocarbons on the catalyst are stripped off in a stripping stage; these two stages are located within the same vessel; ③ The resulting naphtha comes into contact with the high-temperature regenerated catalyst in a second stage, where the cracking reaction products are separated, and under reaction conditions the naphtha is cracked to produce more low-boiling-point hydrocarbons including propylene; ④ In the separation stage, the low-boiling-point hydrocarbons are separated from the catalyst slurry particles, and they are stripped off in the stripping stage, resulting in a catalyst free of coke; ⑤ The catalyst is then sent to a regeneration stage, where it comes into contact with oxygen and is coked under certain conditions to produce a high-temperature regenerated catalyst; ⑥ The high-temperature regenerated catalyst is fed into the first and second cracking stages located in the same lift tube. Patent claim: An improved FCC method for increasing propylene production, comprising: ① a single reactor; ② a single reactor-distiller combination; ③ at least one riser reaction section for the catalytic cracking of feedstock. The particle cracking catalyst includes a type of USY zeolite and an amorphous binder. This method includes: (1) adding at least one separation riser; (2) incorporating a ZSM25-containing granular catalyst into the cracking catalyst to form a composite catalyst; (3) recovering the crackable naphtha, which has a fraction content of over 50% and a boiling point range of 16–149 °C, and feeding it into the separation riser along with the composite catalyst particles to undergo catalytic cracking under reaction conditions in order to produce more propylene. Used in the fluidized catalytic cracking process. The production of light olefins, including propylene, has increased. Improving the physical and catalytic properties of FCC catalysts: Before the spray drying step, an acid-stable anionic fluorohydrocarbon surfactant – EP 462216-B1 from THIELE KAOLINCO – is added. By incorporating this acid-stable anionic fluorohydrocarbon surfactant (A) into the FCC catalysts, their physical and catalytic properties can be improved. The aging properties of kaolin can be improved by adding an effective amount of A to its slurry. The physical properties and catalytic characteristics of an FCC catalyst based on a sol matrix can be improved through the following methods: ① Prepare an acidic aluminum sulfate and silica sol binder component (B); ② Prepare a slurry component (C); ③ Combine (B) and (C); ④ Prepare a zeolite slurry component (D); ⑤ Prepare an alumina slurry component (E); ⑥ Add an effective amount of (A) to at least one of the components; ⑦ Combine the various components mentioned above and spray-dry them; ⑧ Wash, exchange, dry, calcine, and recover the final catalyst product. This post was last edited by Shuichangshou on 2009-3-12 08:11]