Catalyst regeneration

Patent metadata

Field	Value
Publication number	US-10654035-B2
Application number	US-201716079362-A
Country	US
Kind code	B2
Filing date	Feb 22, 2017
Priority date	Mar 1, 2016
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

The present disclosure provides an air-soak containing regeneration process reducing its time. The process includes (i) removing surface carbon species from a gallium-based alkane dehydrogenation catalyst in a combustion process in the presence of a fuel gas; (ii) conditioning the gallium-based alkane dehydrogenation catalyst after (i) in air-soak treatment at a temperature of 660° C. to 850° C. with (iii) a flow of oxygen-containing gas having (iv) 0.1 to 100 parts per million by volume (ppmv) of a chlorine source selected from chlorine, a chlorine compound or a combination thereof; and achieving a predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) 10% to 50% sooner in air-soak treatment than that required to achieve the same predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).

First claim

What is claimed is:

1. A method of reducing a time of an air-soak treatment in a regeneration process, comprising:
(i) removing surface carbon species from a gallium-based alkane dehydrogenation catalyst in a combustion process using a fuel gas; and
(ii) conditioning, after the surface carbon species is removed from the gallium-based alkane dehydrogenation catalyst, the gallium-based alkane dehydrogenation catalyst in the air-soak treatment at a temperature of 660 degree Celsius (° C.) to 850° C. with (iii) a flow of oxygen-containing gas having (iv) 0.1 to 100 parts per million by volume (ppmv) of a chlorine source selected from chlorine, a chlorine compound or a combination thereof,
wherein a predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process is achieved using (i) through (iv) at least 10% to 50% sooner in air-soak treatment than a time required to achieve the same predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak treatment containing regeneration process using (i) through (iii), but without (iv).

2. The method of claim 1 , wherein conditioning the gallium-based alkane dehydrogenation catalyst after (i) in the air-soak treatment includes using (iv) with 5 to 90 ppmv of the chlorine source.

3. The method of claim 2 , wherein conditioning the gallium-based alkane dehydrogenation catalyst after (i) in the air-soak treatment includes using (iv) with 21 to 61 ppmv of the chlorine source.

4. The method of claim 2 , wherein conditioning the gallium-based alkane dehydrogenation catalyst after (i) in air-soak treatment includes conditioning the gallium-based alkane dehydrogenation catalyst at a temperature in a range from 680° C. to 770° C.

5. The method of claim of claim 1 , where achieving the predetermined alkane conversion percentage of 10% at a weight hourly space velocity of 100 h −1 and a reaction temperature of 620° C. for the gallium-based alkane dehydrogenation catalyst occurs 26% to 33% sooner in air-soak treatment for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) as compared to the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).

6. The method of claim 1 , where achieving the predetermined alkane conversion percentage of 15% at a weight hourly space velocity of 100 h −1 and a reaction temperature of 620° C. for the gallium-based alkane dehydrogenation catalyst occurs 22% to 26% sooner in air-soak treatment for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) as compared to the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).

7. The method of claim 1 , where achieving the predetermined alkane conversion percentage of 20% at a weight hourly space velocity of 100 h −1 and a reaction temperature of 620° C. for the gallium-based alkane dehydrogenation catalyst occurs 27% to 31% sooner in air-soak treatment for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) as compared to the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).

8. The method of claim 1 , where achieving the predetermined alkane conversion percentage of 22% at a weight hourly space velocity of 100 h −1 and a reaction temperature of 620° C. for the gallium-based alkane dehydrogenation catalyst occurs 22% to 26% sooner in air-soak treatment for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) as compared to the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).

9. The method of claim 1 , wherein the gallium-based alkane dehydrogenation catalyst includes a platinum (Pt) based promoter and an optional promotor metal on a catalyst support selected from the group consisting of aluminium oxide (Al 2 O 3 ), silicon dioxide, silica-alumina composites, rare earth modified alumina, and combinations thereof.

10. The method of claim 9 , where the optional promotor metal is potassium (K).

11. The method of claim 10 , where the Pt based promoter provides a Pt loading of 0.1 to 500 parts per million (ppm) based on the total weight of the catalyst and the optional promoter has a K loading of 0 to 1 weight percent (wt. %) based on the total weight of the catalyst.

12. The method of claim 1 , chlorine compound is selected from the group consisting of chlorinated hydrocarbons, HCl gas, chlorine (Cl 2 ) gas, and combinations thereof.

13. The method of claim 1 , wherein the chlorine source is monochloroethane.

14. The method of claim 1 , wherein the predetermined alkane conversion percentage is for propane.

15. An improved process for dehydrogenating an alkane, the process comprising placing an alkane in operative contact with a heated alkane dehydrogenation catalyst in a reactor, the catalyst comprising a Group VIII noble metal, a Group IIIA metal and, optionally, a promoter metal, removing from the reactor a partially deactivated catalyst, rejuvenating the partially deactivated catalyst in a regenerator, and transporting the rejuvenated catalyst from the regenerator to the reactor, wherein the improvement comprises a combination of treatment within the regenerator and transport of the rejuvenated catalyst from the regenerator to the reactor, the treatment within the regenerator comprising sequential steps:
a. heating the partially deactivated catalyst to a temperature of at least 660 degrees Celsius using heat generated combustion products obtained by combusting both coke contained on the partially deactivated catalyst and a fuel source other than the coke, the heating yielding a heated, further deactivated catalyst which has an alkane dehydrogenation activity that is less than that of the partially deactivated catalyst;
b. subjecting the heated, further deactivated catalyst to a conditioning step which comprises maintaining the heated, further deactivated dehydrogenation catalyst at a temperature of at least 660 degrees Celsius while exposing the heated, further deactivated dehydrogenation catalyst to a flow of an oxygen-containing gas with a chlorine or chlorine containing compound with an overall Cl concentration 0.1 ppm-volume to 100 ppm-volume for a period of time sufficient to yield an oxygen-containing reactivated dehydrogenation catalyst that has an activity for dehydrogenating alkane that is greater than that of either the partially deactivated catalyst or the further deactivated catalyst; and, optionally,
c. maintaining the oxygen-containing reactivated catalyst at a temperature of at least 660 degrees Celsius while exposing the reactivated catalyst to a flow of stripping gas that is substantially free of molecular oxygen and combustible fuel for a period of time greater than two minutes and sufficient to remove from the oxygen-containing reactivated dehydrogenation catalyst at least a portion of molecular oxygen trapped within or between catalyst particles and chemisorbed oxygen that is desorbable at the temperature during that period of time and yield a rejuvenated dehydrogenation catalyst; with

transport

Assignees

• Dow Global Technologies Llc

Inventors

• Malek Andrzej
• Barton David Gordon
• Luo Lin

Classifications

• B01J38/18

  with subsequent reactive gas treating · CPC title

• B01J38/30

  in gaseous suspension, e.g. fluidised bed · CPC title

• B01J38/14

  with control of oxygen content in oxidation gas · CPC title

• B01J23/62

  with gallium, indium, thallium, germanium, tin or lead · CPC title

• B01J23/08 Primary

  of gallium, indium or thallium · CPC title