On-site generation, purification, and distribution of ultra-pure anhydrous ammonia

• US 20050260108A1
• Filed: 05/17/2005
• Published: 11/24/2005
• Est. Priority Date: 05/18/2004
• Status: Active Grant

• Current Assignee: Matheson Tri-Gas Incorporated (Mitsubishi Chemical Group Corp.)
• Original Assignee: Matheson Tri-Gas Incorporated (Mitsubishi Chemical Group Corp.)
• Inventors: Spicer, Harold G., Del Prato, Thomas A.
• Granted Patent: US 7,371,313 B2
• Time in Patent Office: Days
• US Class Current: 422/168
• CPC Class Codes: B01D 53/79 Injecting reactants
• CPC Class Codes: C01C 1/024 Purification
• CPC Class Codes: C01C 1/086 from urea
• CPC Class Codes: C01P 2006/80 Compositional purity

Abstract

A system and method for generating, purifying, and using ultra-pure ammonia on-site, such as at a semiconductor manufacturing facility. The system includes an ammonia generation system configured to generate ammonia including carbon dioxide, water, and other impurities. A purification system is provided with the generation system in the manufacturing facility and is linked to the output of the generation system. The purification system processes the effluent from the ammonia generation system to remove substantially all of the carbon dioxide, water, and other impurities to produce an outlet stream of ultra-pure ammonia. The system further includes a point of use system provided at the same manufacturing facility to utilize the outlet stream of ultra-pure ammonia.

Claims

1. A method for on-site generation and purification of ultra-pure ammonia, comprising:

generating ammonia in a reactor to produce a first effluent comprising ammonia and impurities;

processing the first effluent with an absorption apparatus fluidly connected to the reactor to produce a bottom fraction comprising ammonia, water, minor amounts of carbon dioxide and trace levels of impurities;

processing the absorption apparatus bottom fraction with a first distillation apparatus fluidly connected to the absorption apparatus to produce an overhead fraction comprising ammonia having minor amounts of water and trace levels of impurities;

flowing the overhead fraction from the first distillation apparatus through a first purification system containing a first purifier material and fluidly connected to said first distillation apparatus to produce a second effluent comprising ammonia having less than about 10,000 ppm water, minor amounts of carbon dioxide, and trace levels of impurities;

flowing the second effluent through a second purification system containing a second purifier material and fluidly connected to the first purification system to produce a third effluent comprising ammonia having less than about 10,000 ppm water, minor amounts of carbon dioxide, and trace levels of impurities;

processing the third effluent with a second distillation apparatus fluidly connected to the second purification system to produce a bottom fraction comprising ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide, and less than about 200 ppm other impurities;

flowing the bottom fraction from the second distillation apparatus through a third purification system containing a third purifier material and fluidly connected to the third distillation apparatus to provide a fourth effluent comprising ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide and less than about 200 ppm other impurities; and

flowing the fourth effluent through a fourth purification system containing a fourth purifier material and fluidly connected to the third purification system to produce ultra-pure ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide, and less than about 200 ppm other impurities.

2. The method of claim 1, wherein said ammonia is generated by hydrolyzing urea in aqueous solution in a closed reactor to generate a first effluent comprising ammonia, carbon dioxide, and water.

3. The method of claim 2, wherein said urea is dry urea.

4. The method of claim 2, wherein said urea is an aqueous solution comprising 50-70% urea.

5. The method of claim 2, wherein said reaction occurs below about 150°

C. and below about 2.5 MPa.

6. The method of claim 1, wherein said ammonia is generated by an electrochemical reaction between hydrogen and nitrogen.

7. The method of claim 1, wherein said ammonia is generated by reacting gaseous hydrogen and nitrogen over a metal catalyst at 475°

C. and 20 MPa.

8. The method of claim 1, wherein said first purifier material is at least one material selected from molecular sieves, silica gel, and zeolites.

9. The method of claim 1, wherein said second purifier material is at least one material selected from molecular sieves, activated alumina, or modified alumina.

10. The method of claim 1, wherein said third purifier material is modified alumina.

11. The method of claim 1, wherein the produced ultra-pure ammonia has a purity level greater than about 99.0 percent, wherein the produced ultra-pure ammonia is provided to an inlet of a point of use system in fluid communication with the fourth purification system, and wherein the reactor, the point of use system, and components for performing the processing and the flowing steps are contained in a manufacturing facility, whereby the produced ultra-pure ammonia is generated, purified, and used on a single on-site.

12. The method of claim 1, wherein the second effluent comprises less than about 100 ppm water, and the third effluent comprises less than about 5 ppm water.

13. The method of claim 1, wherein the fourth effluent comprises less than about 100 ppb water, less than about 0.4 ppm carbon dioxide, and less than about 2 ppm other impurities.

14. An on-site ultra-pure ammonia generation system, comprising:

an ammonia generation system comprising a reactor generating a first effluent at an outlet, the reactor effluent comprising ammonia, carbon dioxide, and water; and

a purification system with an inlet connected to the reactor outlet for receiving the first effluent, wherein the purification system processes the first effluent to remove substantially all of the carbon dioxide and the water to produce an outlet stream comprising 99.0 percent or greater purity ammonia; and

a point of use system adapted for utilizing the outlet stream and having an ammonia input fluidically connected to the purification system to receive the ammonia outlet stream, wherein the ammonia generation system, the purification system, and the point of use system are housed in a manufacturing facility.

15. The system of claim 14, wherein the purification system comprises:

an absorption apparatus fluidly connected to the reactor outlet operable to produce a bottom fraction comprising ammonia, water, minor amounts of carbon dioxide and trace levels of impurities;

a first distillation apparatus fluidly connected to the absorption apparatus adapted for processing the absorption apparatus bottom fraction to produce an overhead fraction comprising ammonia having minor amounts of water and trace levels of impurities; and

a first purification device containing a first purifier material and fluidly connected to said first distillation apparatus through which the overhead fraction from the first distillation apparatus is forced to flow to produce a second effluent comprising ammonia having less than about 10,000 ppm water, minor amounts of carbon dioxide, and trace levels of impurities.

16. The system of claim 15, the purification system further comprising:

a second purification device containing a second purifier material and fluidly connected to the first purification device, wherein the second effluent flows through the second purifier material to produce a third effluent comprising ammonia having less than about 5 ppm water;

a second distillation apparatus for processing the third effluent fluidly connected to the second purification device to produce a bottom fraction comprising ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide, and less than about 200 ppm other impurities;

a third purification device containing a third purifier material and fluidly connected to the third distillation apparatus, wherein the bottom fraction from the second distillation apparatus flows through the third purifier material to provide a fourth effluent comprising ammonia having less than about 100 ppb water, less than about 0.4 ppm carbon dioxide, and less than about 2 ppm other impurities; and

a fourth purification device containing a fourth purifier material and fluidly connected to the third purification device, wherein the fourth effluent is caused to flow through the fourth purifier material to produce the ultra-pure ammonia.

17. The system of claim 14, wherein the purification system processes the first effluent at a temperature greater than about 100°

C. to limit formation of ammonium carbamate and ammonium carbonate.

18. A method for on-site generation and purification of ultra-pure ammonia, comprising:

generating ammonia in a reactor to produce a first effluent comprising ammonia;

processing the first effluent with an absorption apparatus fluidly connected to the reactor to produce a bottom fraction comprising ammonia, water, and carbon dioxide;

processing the absorption apparatus bottom fraction with a first distillation apparatus fluidly connected to the absorption apparatus to produce an overhead fraction comprising ammonia having minor amounts of water;

flowing the overhead fraction from the first distillation apparatus through a first purification system containing a first purifier material and fluidly connected to said first distillation apparatus to produce a second effluent comprising ammonia having less than about 10,000 ppm water and carbon dioxide; and

outputting the ammonia from the first purification system to an inlet of a point of use system, wherein the point of use system, the reactor, the absorption apparatus, the first distillation apparatus, and the first purification system are provided at a single manufacturing facility, whereby the point of use system is supplied with purified ammonia without requiring storage and handling of liquid ammonia sources.

19. The method of claim 18, further comprising prior to the outputting:

flowing the second effluent through a second purification system containing a second purifier material and fluidly connected to the first purification system and provided at the manufacturing facility to produce a third effluent comprising ammonia having less than about 5 ppm water;

processing the third effluent with a second distillation apparatus provided at the manufacturing facility fluidly connected to the second purification system to produce a bottom fraction comprising ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide, and less than about 200 ppm other impurities;

flowing the bottom fraction from the second distillation apparatus through a third purification system containing a third purifier material, provided at the manufacturing facility, and fluidly connected to the third distillation apparatus to provide a fourth effluent comprising ammonia having less than about 100 ppb water and less than about 0.4 ppm carbon dioxide; and

flowing the fourth effluent through a fourth purification system containing a fourth purifier material, provided at the manufacturing facility, and fluidly connected to the third purification system to produce ultra-pure ammonia, wherein the ultra-pure ammonia is transmitted to the inlet of the point of use system.

20. The method of claim 18, wherein said ammonia is generated by hydrolyzing urea in aqueous solution in a closed reactor to generate a first effluent comprising ammonia, carbon dioxide, and water.

21. The method of claim 20, wherein said urea is dry urea.

22. The method of claim 20, wherein said urea is an aqueous solution comprising 50-70% urea.

23. The method of claim 20, wherein said reaction occurs below about 150°

C. and below about 2.5 MPa.

24. The method of claim 18, wherein said ammonia is generated by an electrochemical reaction between hydrogen and nitrogen.

25. An on-site ultra-pure ammonia generation system, comprising:

an ammonia generation system comprising a system generating an effluent at an outlet, the reactor effluent comprising ammonia and impurities; and

a purification system with an inlet connected to the reactor outlet for receiving the reactor effluent, wherein the purification system processes the reactor effluent to remove substantially all of the impurities to produce an outlet stream comprising 99.0 percent or greater purity ammonia, the purification system comprising;

an absorption apparatus fluidly connected to the reactor outlet operable to produce a fraction comprising ammonia, water, carbon dioxide and impurities;

a first distillation apparatus fluidly connected to the absorption apparatus adapted for processing the absorption apparatus fraction to produce a fraction comprising ammonia having minor amounts of water and trace levels of impurities; and

a first purification device containing a first purifier material and fluidly connected to said first distillation apparatus through which the fraction from the first distillation apparatus is forced to flow to produce the outlet stream comprising ammonia having less than about 10,000 ppm water, minor amounts of carbon dioxide, and trace levels of impurities; and

a point of use system adapted for utilizing the outlet stream and having an ammonia intake fluidically connected to the purification system to receive the ammonia outlet stream.

26. The system of claim 25, wherein the ammonia generation system, the purification system, and the point of use system are housed in a manufacturing facility.

27. The system of claim 25, the purification system further comprising:

a second purification system containing a second purifier material and fluidly connected to the first purification system, wherein effluent from the first purification system flows through the second purifier material to produce an effluent comprising ammonia having less than about 5 ppm water; and

a second distillation apparatus for processing the effluent from the second purification system and fluidly connected to the second purification system to produce a fraction making up the outlet stream comprising ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide, and less than about 200 ppm other impurities;

28. The system of claim 27, the purification system further comprising:

a third purification system containing a third purifier material and fluidly connected to the second distillation apparatus, wherein the fraction from the second distillation apparatus flows through the third purifier material to provide an effluent comprising ammonia having less than about 100 ppb water, less than about 0.4 ppm carbon dioxide, and less than about 2 ppm other impurities; and

a fourth purification system containing a fourth purifier material and fluidly connected to the third purification system, wherein the effluent from the third purification system is caused to flow through the fourth purifier material to produce the ultra-pure ammonia of the outlet stream.

29. A method for generating ultra-pure ammonia for on-site use, comprising:

operating a reactor to generate a first effluent at an outlet of the reactor, the first effluent comprising ammonia and impurities;

receiving the first effluent at an inlet to a purification system connected to the reactor outlet;

processing the received first effluent with the purification system to remove substantially all of the impurities to produce an outlet stream comprising 99.0 percent or greater purity ammonia; and

utilizing the outlet stream from the purification system with a point of use system connected to the purification system, wherein the reactor, the purification system, and the point of use system are provided at a single facility.

30. The method of claim 29, wherein the processing of the first effluent comprises:

with an absorption apparatus fluidly connected to the reactor outlet, producing a bottom fraction comprising ammonia, water, minor amounts of carbon dioxide and trace levels of impurities;

with a first distillation apparatus fluidly connected to the absorption apparatus, processing the absorption apparatus bottom fraction to produce an overhead fraction comprising ammonia having minor amounts of water and trace levels of impurities; and

with a first purification device containing a first purifier material and fluidly connected to said first distillation apparatus, causing the overhead fraction from the first distillation apparatus to flow through the first purifier material to produce a second effluent comprising ammonia having less than about 10,000 ppm water, minor amounts of carbon dioxide, and trace levels of impurities, the outlet stream comprising the second effluent.

31. The method of claim 30, wherein the processing of the first effluent further comprises:

with a second purification device containing a second purifier material and fluidly connected to the first purification device, causing the second effluent to flow through the second purifier material to produce a third effluent comprising ammonia having less than about 5 ppm water;

with a second distillation apparatus connection to the second purification device processing the third effluent to produce a bottom fraction comprising ammonia having less than about 10,000 ppm water, less than about 40 ppm carbon dioxide, and less than about 200 ppm other impurities;

with a third purification device containing a third purifier material and fluidly connected to the third distillation apparatus, causing the bottom fraction from the second distillation apparatus to flow through the third purifier material to provide a fourth effluent comprising ammonia having less than about 100 ppb water, less than about 0.4 ppm carbon dioxide, and less than about 2 ppm other impurities; and

with a fourth purification device containing a fourth purifier material and fluidly connected to the third purification device, causing the fourth effluent to flow through the fourth purifier material to produce ultra-pure ammonia provided in the outlet stream.