Catalyst demetallization by converting the metal poisons to a sulfur containing metal compound having a defined low amount of sulfur

Claim 2

A process for treating iron, nickel and vanadium contaminated catalyst which has been poisoned in a hydrocarbon conversion process by a feedstock containing those metal poisons to remove at least a portion of these metal contaminants and to produce a catalyst with improved catalytic activity which comprises contacting at least a portion of said metal contaminated catalyst with at least one sulfur containing compound to provide a catalyst containing sulfur containing metal compounds wherein the amount of sulfur present on the catalyst is about 40 to about 90% of the total amount of iron, nickel and vanadium initially present on the catalyst; contacting said catalyst containing sulfur containing metal compounds with an oxygen containing medium to promote subsequent metals removal by converting at least a portion of said catalyst metals to a dispersible form; contacting said oxygen treated catalyst with an aqueous reductive wash medium to remove at least a portion of said metal poisons and subjecting said reductively washed catalyst to an aqueous oxidative wash; and recovering a catalyst of reduced metal poison content and improved catalytic activity.

Claim 3

A process as in claim 1 wherein said oxygen containing medium comprises an oxygen containing gas.

Claim 4

A process as in claim 2 wherein said oxygen containing gas contacts said catalyst at a temperature within the range of from 550° F. to 725° F.

Claim 5

A process as in claim 2 wherein the oxygen containing gas contacts said catalyst within the temperature range of from about 600° F. to about 700° F.

Claim 6

A process as in claim 2 wherein the oxygen containing gas contacts said catalyst within the temperature range of from about 620° F. to about 680° F.

Claim 7

A process as in claim 2 which includes the presence of steam during said oxygen contact step.

Claim 8

A process as in claim 1 wherein the reductive, aqueous wash medium is a solution of SO 2 in water.

Claim 9

A process as in claim 7 wherein the solution is a saturated SO 2 solution.

Claim 10

A process as in claim 8 wherein said reductive wash includes a temperature of about 65°-80° C. and a contact time of about 0.5-10 minutes.

Claim 11

A process as in claim 9 where said contact time is about 1-5 minutes.

Claim 12

A process as in claim 1 wherein the oxidative wash medium is an aqueous solution of hydrogen peroxide.

Claim 13

A process as in claim 11 wherein said oxidative wash includes a temperature of about 70°-85° C. and a contact time of about 3-5 minutes.

Claim 14

A process as in claim 12 wherein said aqueous hydrogen peroxide comprises about 2 to 30 weight % hydrogen peroxide.

Claim 15

A process as in claim 1 which further comprises removing at least a portion of the metal poisons from the oxygen treated catalyst by contacting said oxygen treated catalyst with alternate reductive and oxidative washes, the last wash comprising an oxidative wash.

Claim 16

A process as in claim 1 wherein the contaminated catalyst comprises a zeolite molecular sieve.

Claim 17

A process as in claim 15 wherein said zeolitic molecular sieve comprises a decationized zeolitic molecular sieve having less than 90% of the aluminum atoms associated with cations, a crystalline structure capable of internally absorbing benzene and a SiO 2 to Al 2 O 3 molar ratio greater than 3.

Claim 18

A process as in claim 1 wherein said sulfur containing compound is hydrogen sulfide or a sulfur containing compound capable of being converted to hydrogen sulfide.

Claim 19

A process as in claim 17 wherein said sulfur containing compound is an admixture with a reducing gas.

Claim 20

A process as in claim 18 wherein said reducing gas is hydrogen or carbon monoxide.

Claim 21

A process as in claim 1 wherein the amount of sulfur present in the catalyst is about 40 to 75% of the total amount of nickel, iron and vanadium.

Claim 22

In a catalytic cracking process for converting a metals contaminated hydrocarbon feedstock to more valuable, lower boiling hydrocarbon products in a cracking reaction zone wherein the cracking catalyst is poisoned and contaminated by metals including iron, nickel and vanadium present in the feedstock, the improvement which comprises (i) withdrawing at least a portion of said metal contaminated catalyst from the cracking reaction zone; (ii) contacting at least a portion of said metal contaminated catalyst with at least one sulfur containing compound to provide a catalyst containing sulfur containing metals compounds wherein the amount of sulfur present on the resultant catalyst is about 40 to about 90% of the total amount of iron, nickel and vanadium initially present on the catalyst; (iii) contacting said catalyst containing sulfur containing metal compound with an oxygen-containing medium to promote subsequent metals removal by converting at least a portion of said catalyst metals to a dispersible form; (iv) contacting said oxygen treated catalyst with an aqueous reductive wash medium and subjecting said reductively washed catalyst to an aqueous oxidative wash to remove at least a portion of the metal poisons from the oxygen treated catalyst; (v) recovering a catalyst of reduced metal poison content and improved catalytic activity; and (vi) returning at least a portion of said recovered catalyst to the catalytic cracking process.

Claim 23

In a catalytic cracking process for converting a metals contaminated hydrocarbon feedstock to more valuable, lower boiling hydrocarbon products in a cracking reaction zone wherein the cracking catalyst is poisoned and contaminated by metals including iron, nickel and vanadium present in the feedstock, the improvement which comprises (i) withdrawing at least a portion of said metal contaminated catalyst from the cracking reaction zone; (ii) contacting at least a portion of said metal contaminated catalyst with at least one sulfur containing compound to provide a catalyst containing sulfur containing metals compounds wherein the amount of sulfur present on the resultant catalyst is about 40 to about 90% of the total amount of iron, nickel and vanadium initially present on the catalyst; (iii) contacting said catalyst containing sulfur containing metal compound with an oxygen-containing medium to promote subsequent metals removal by converting at least a portion of said catalyst metals to a dispersible form; (iv) contacting said oxygen treated catalyst with an aqueous reductive wash medium and subjecting said reductively washed catalyst to an aqueous oxidative wash to remove at least a portion of the metal poisons from the oxygen treated catalyst; (v) recovering a catalyst of reduced metal poison content and improved catalytic activity; and (vi) returning at least a portion of said recovered catalyst to the catalytic cracking process.

Claim 24

A process as in claim 21 wherein said oxygen containing medium comprises an oxygen containing gas.

Claim 25

A process as in claim 22 wherein said oxygen containing gas contacts said catalyst at a temperature within the range of from about 550° F. to 725° F.

Claim 26

A process as in claim 22 wherein the oxygen-containing gas contacts said catalyst within the temperature range of from about 600° F. to about 700° F.

Claim 27

A process as in claim 22 wherein the oxygen-containing gas contacts said catalyst within the temperature range of from about 620° F. to about 680° F.

Claim 28

A process as in claim 22 which includes the presence of steam during said oxygen contact step.

Claim 29

A process as in claim 21 wherein the reductive aqueous wash medium is a solution of SO 2 in water.

Claim 30

A process as in claim 27 wherein the solution is a saturated SO 2 solution.

Claim 31

A process as in claim 28 wherein said reductive wash includes a temperature of about 65°-80° C. and a contact time of about 0.5-10 minutes.

Claim 32

A process as in claim 29 where said reductive wash contact time is about 1-5 minutes.

Claim 33

A process as in claim 29 wherein the oxidative wash medium is an aqueous solution of hydrogen peroxide.

Claim 34

A process as in claim 31 wherein said reductive wash includes a temperature of about 60°-85° C. and a contact time of about 1-5 minutes.

Claim 35

A process as in claim 32 wherein said aqueous hydrogen peroxide comprises about 2 to 30 weight % hydrogen peroxide.

Claim 36

A process as in claim 21 which further comprises removing at least a portion of the metal poisons from the oxygen treated catalyst by contacting said oxygen treated catalyst with alternate reductive and oxidative washes, the last wash comprising an oxidative wash.

Claim 37

A process as in claim 21 wherein the contaminated catalyst comprises a zeolitic molecular sieve.

Claim 38

A process as in claim 35 wherein said zeolitic molecular sieve comprises a decationized zeolitic molecular sieve having less than 90% of the aluminum atoms associated with cations, a crystalline structure capable of internally absorbing benzene and a SiO 2 to Al 2 O 3 molar ratio greater than 3.

Claim 39

A process as in claim 21 wherein said sulfur containing compound is hydrogen sulfide or a sulfur containing compound capable of being converted to hydrogen sulfide.

Claim 40

A process as in claim 37 wherein said sulfur containing compound is an admixture with a reducing gas.

Claim 41

A process as in claim 38 wherein said reducing gas is hydrogen or carbon monoxide.

Claim 42

A process as in claim 21 wherein the amount of sulfur on the catalyst is about 40 to 75% of the total amount of iron, nickel and vanadium.