Selective hydrogenation method

Patent metadata

Field	Value
Publication number	US-9790442-B2
Application number	US-201414574311-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Dec 17, 2014
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

The present subject matter relates generally to methods for selectively saturating the unsaturated C 2 -C 4 . More specifically, the present subject matter relates to methods for saturating butadiene and butenes from a hydrocarbon stream before it is combined with a fresh feed and enters a reaction zone. Removing the unsaturates from the hydrocarbon stream before the hydrocarbon stream enters the reaction zone prevents the reactor internals from coking.

First claim

The invention claimed is:

1. A method for saturating hydrocarbons comprising:
providing a hydrocarbon stream comprising paraffins having 4 or less carbon atoms, C2-C4 olefins, diolefins, aromatics, H 2 O, H 2 S, and other sulfur containing compounds, wherein the hydrocarbon stream comprises a portion of an effluent from a dehydrocyclodimerization reaction zone;
passing the hydrocarbon stream to a guard bed and contacting the hydrocarbon stream with an adsorbent to remove H 2 O, H 2 S, and other sulfur containing compounds and form a treated hydrocarbon stream; and
passing the treated hydrocarbon stream and a hydrogen stream to a reaction zone containing a hydrogenation catalyst to selectively hydrogenate the olefins and diolefins in the treated hydrocarbon stream and form a reaction zone effluent stream, wherein greater than about 60% by weight of the olefins are saturated, greater than about 80% by weight of the diolefins are saturated, and no more than 20% by weight of the aromatics are saturated.

2. The method of claim 1 , wherein the guard bed contains molecular sieves to remove H 2 O.

3. The method of claim 1 , wherein the guard bed contains molecular sieves to remove H 2 O and H 2 S.

4. The method of claim 1 , wherein the guard bed contains molecular sieves and metal or metal oxides that are capable of going through reduction-oxidation cycle to remove H 2 S and other sulfur containing compounds.

5. The method of claim 1 , wherein the reaction zone comprises multiple reactors in series having inter-stage quenching.

6. The method of claim 5 , wherein the inter-stage quenching includes dividing H 2 and injecting it into individual reactors.

7. The method of claim 1 , wherein the reaction zone operates at a temperature from about 60° C. (140° F.) to about 350° C. (662° F.).

8. The method of claim 1 , wherein the reaction zone operates at a pressure from about 40 psig to about 300 psig.

9. The method of claim 1 , wherein the hydrogenation catalyst comprises at least one active metal chosen from Groups 6 through 10.

10. The method of claim 1 , wherein the hydrogenation catalyst comprises one or more transition metals selected from nickel, palladium, platinum, rhodium, iridium and mixtures thereof supported on inorganic metal oxides.

11. The method of claim 1 , wherein the hydrogenation catalyst comprises at least one Group VIII metal selected from nickel, palladium, platinum and mixtures thereof supported on an inorganic oxide.

12. The method of claim 1 , wherein an overall H 2 to olefin molar ration in the reaction zone range from 0.5 to 5.0.

13. The method of claim 1 , wherein the guard bed operates over a cycle from 2 to 48 hours.

14. The method of claim 1 , wherein the diolefins comprise greater than 50% by weight butadiene.

15. The method of claim 1 , further comprising:
passing a feed stream comprising aliphatic hydrocarbons to a dehydrocyclodimerization reaction zone to form a reaction mixture comprising aromatics, C4+ non-aromatics byproduct, a light ends byproduct comprising C1-C2 hydrocarbons, C2-C4 olefins, diolefins, unconverted aliphatic hydrocarbons, H 2 O, H 2 S, and other sulfur containing compounds;
separating the reaction mixture to form the hydrocarbon stream.

16. The method of claim 15 , further comprising:
recycling the reaction zone effluent stream to the dehydrocyclodimerization reaction zone.

Assignees

• Uop Llc

Inventors

• Cox Pelin
• Jan Deng-Yang

Classifications

• C10G25/00

  Refining of hydrocarbon oils in the absence of hydrogen, with solid sorbents · CPC title

• C10G67/06

  including a sorption process as the refining step in the absence of hydrogen · CPC title

• C10G70/02 Primary

  by hydrogenation · CPC title

• C10G45/00

  Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds · CPC title

• C10G45/32

  Selective hydrogenation of the diolefin or acetylene compounds · CPC title