Processes for stabilizing antimony catalysts

Patent metadata

Field	Value
Publication number	US-11235313-B2
Application number	US-202016797869-A
Country	US
Kind code	B2
Filing date	Feb 21, 2020
Priority date	Feb 21, 2019
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

First claim

We claim:

1. A process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process, the process comprising:
providing an antimony ammoxidation catalyst to a fluidized bed reactor;
reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and
adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity;
wherein the antimony-containing compound has a melting point less than 375° C.

2. The process of claim 1 , wherein the catalyst conversion is maintained within 10% of a target conversion over a period of at least 1 year.

3. The process of claim 1 , wherein the catalyst selectivity to acrylonitrile is maintained within 10% of a target selectivity over a period of at least 1 year.

4. The process of claim 1 , wherein the catalyst conversion is at least 45% over a period of at least 1 year.

5. The process of claim 1 , wherein the catalyst selectivity to acrylonitrile is at least 50% over a period of at least 1 year.

6. The process of claim 1 , wherein the antimony-containing compound is a solid.

7. The process of claim 1 , wherein the adding is conducted at a temperature of less than 300° C.

8. The process of claim 1 , wherein the antimony-containing compound comprises an antimony acetate.

9. The process of claim 1 , further comprising the step of releasing antimony ammoxidation catalyst vapors from the antimony ammoxidation catalyst in the reactor.

10. The process of claim 9 , further comprising the step of vaporizing the antimony-containing compound to suppress the release of the antimony ammoxidation catalyst vapors.

11. The process of claim 1 , wherein the adding comprises:
adding the antimony-containing compound directly into a catalyst hopper comprising replenishing the antimony ammoxidation catalyst and then feeding the resultant replenished antimony catalyst composition to the reactor;
mixing the antimony-containing compound with the antimony ammoxidation catalyst and then feeding the resultant replenished antimony catalyst composition directly to the reactor;
dissolving antimony-containing compound in water to form an aqueous solution and then adding the aqueous solution to the reactor; or
combinations thereof.

12. The process of claim 1 , wherein the antimony-containing compound and the antimony ammoxidation catalyst comprises less than 1 wt % potassium, lithium, sodium, cesium, indium, rubidium, samarium, calcium, strontium, barium or tellurium.

13. The process of claim 1 , wherein the antimony ammoxidation catalyst further comprises molybdenum and/or a molybdenum oxide.

14. The process of claim 1 , wherein the adding step further comprises adding an effective amount of a molybdenum-containing compound to the antimony ammoxidation catalyst.

15. The process of claim 1 , wherein the antimony-containing compound comprises antimony triacetate, antimony oxides, or organoantimony compounds, or combinations thereof.

16. The process of claim 1 , wherein the adding further comprises adding at least one additive to the fluidized bed reactor.

Assignees

• Ascend Performance Mat Operations Llc

Inventors

• Chi Y T
• Moffatt Scott
• Tjaden John
• Loyd Chelsea
• Ables Lori

Classifications

• C07C255/08

  Acrylonitrile; Methacrylonitrile · CPC title

• C07C253/26 Primary

  containing carbon-to-carbon multiple bonds, e.g. unsaturated aldehydes · CPC title

• B01J38/02

  Heat treatment · CPC title

• B01J23/92 Primary

  of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 · CPC title

• B01J23/8435

  Antimony · CPC title