Claims
- 1. In a method for cracking a hydrocarbon feedstock to lower molecular weight products in a cracking system comprising a reaction zone, a regeneration zone, and a passivation zone wherein:
- (a) feedstock containing metal contaminant is passed to the reaction zone having cracking catalyst therein wherein the feedstock is cracked to lower molecular weight products and coke, coke and metal contaminant becoming deposited on the catalyst;
- (b) coke and metal contaminated catalyst is passed from the reaction zone to a regeneration zone wherein coke is removed from the catalyst to regenerate the catalyst; and,
- (c) regenerated catalyst from the regeneration zone is passed through a passivation zone prior to return to the reaction zone, the improvement comprising:
- (i) monitoring the octane level of the cracked product; and
- (ii) adjusting the metal contaminant level on the catalyst to maintain the octane level within a predetermined range by the addition to the cracking system of metal contaminated equilibrium cracking catalyst possessing a higher equivalent nickel content than the cracking catalyst in the reaction zone.
- 2. The method of claim 1 wherein the metal contaminant is selected from the group consisting of nickel, vanadium and mixtures thereof.
- 3. The method of claim 2 wherein the metal contaminant level in the cracking catalyst is maintained within the range of about 400 to about 2300 wppm equivalent nickel.
- 4. The method of claim 3 wherein the metal contaminant level on the cracking catalyst is maintained within the range of about 600 to about 2300 wppm equivalent nickel.
- 5. The method of claim 2 wherein the equilibrium cracking catalyst added to the cracking system comprises from about 5 to about 100 wt.% of the total replacement catalyst added to the cracking system.
- 6. The method of claim 2 wherein the Research Octane Number, Clear is maintained within the range of about 85 to about 95.
- 7. In a method for cracking a hydrocarbon feedstock to lower molecular weight products in a cracking system comprising a reaction zone, a regeneration zone, and a passivation zone wherein:
- (a) feedstock containing metal contaminant is passed to the reaction zone wherein the feedstock is cracked to lower molecular weight products and coke, coke and metal contaminant becoming deposited on the catalyst;
- (b) coke and metal contaminated catalyst is passed from the reaction zone to a regeneration zone wherein coke is removed from the catalyst to regenerate the catalyst; and
- (c) regenerated catalyst from the regeneration zone is passed through a passivation zone prior to return to the reaction zone; the improvement comprising:
- (i) monitoring the hydrogen and/or coke production in the reaction zone;
- (ii) monitoring the octane level of the cracked product; and
- (iii) adjusting the metal contaminant level on the catalyst to maintain the hydrogen and/or coke production being monitored in step (i) above and the octane level being monitored in step (ii) above within predetermined ranges by regulating the addition to the cracking system of metal contaminated equilibrium cracking catalyst possessing a higher equivalent nickel content than the cracking catalyst in the cracking zone.
- 8. The method of claim 7 wherein the metal contaminant is selected from the group consisting of nickel, vanadium and mixtures thereof.
- 9. The method of claim 8 wherein the hydrogen production is maintained below about 200 SCF/Barrel of metered feed.
- 10. The method of claim 9 wherein the hydrogen production is maintained below about 150 SCF/Barrel of metered feed.
- 11. The method of claim 10 wherein the hydrogen production is maintained below about 25-75 SCF/Barrel of metered feed.
- 12. The method of claim 8 wherein the equilibrium cracking catalyst added to the system comprises from about 5 to about 100 wt.% of the total cracking catalyst added to the system.
- 13. The method of claim 12 wherein the metal contaminant level on the cracking catalyst is maintained above about 400 wppm equivalent nickel.
- 14. The method of claim 13 wherein the metal contaminant level on the catalyst is maintained within the range of about 600 to about 2300 wppm equivalent nickel.
- 15. In a method for cracking a hydrocarbon feedstock to lower molecular weight products in a cracking system comprising a reaction zone, a regeneration zone, and a passivation zone wherein:
- (a) feedstock containing metal contaminant is passed to the reaction zone having cracking catalyst therein wherein the feedstock is cracked to lower molecular weight products and coke, coke and metal contaminant becoming deposited on the catalyst;
- (b) coke and metal contaminated catalyst is passed from the reaction zone to a regeneration zone wherein coke is removed from the catalyst to regenerate the catalyst; and
- (c) regenerated catalyst from the regeneration zone is passed through a passivation zone prior to return to the reaction zone, the improvement comprising
- (i) monitoring the octane level of the cracked product; and
- (ii) adjusting the metal contaminant level on the catalyst within a predetermined range above about 400 wppm equivalent nickel by the addition to the cracking system of a metal contaminated equilibrium cracking catalyst possessing a higher equivalent nickel content than the cracking catalyst in the reaction zone.
- 16. The method of claim 15 wherein the metal contaminant is selected from the group consisting of nickel, vanadium and mixtures thereof.
- 17. The method of claim 16 wherein the metal contaminant level on the cracking catalyst is maintained within the range of about 600 to about 2300 wppm equivalent nickel by the addition to the cracking system of equilibrium cracking catalyst.
- 18. The method of claim 17 wherein replacement catalyst is added to the cracking system and wherein the equilibrium cracking catalyst added to the cracking system comprises from about 5 to about 100 wt.% of the total replacement catalyst.
Parent Case Info
This is a continuation of application Ser. No. 510,076, filed June 30, 1983, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0052356 |
May 1982 |
EPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
510076 |
Jun 1983 |
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