High pressure cyrogenic process and system for producing ammonia products
View Patent ↗Systems and methods for producing ammonia and/or ammonia products. The ammonia and/or ammonia products can be produced by compressing a gas mixture comprising nitrogen, hydrogen, methane, and argon to produce a compressed gas mixture having a pressure of from about 1,000 kPa (130 psig) to about 10,400 kPa (1,495 psig). All or a portion of the compressed gas mixture can be selectively separated at cryogenic conditions to produce a first gas comprising nitrogen and hydrogen, and a second gas comprising methane, argon, residual hydrogen and nitrogen. At least a portion of the first gas can be reacted at conditions sufficient to produce an ammonia product.
1. A method for producing ammonia, comprising:
methanating a gas comprising about 4 mol % to about 64 mol % nitrogen, about 35 mol % to about 95 mol % hydrogen, about 0.1 mol % to about 0.9 mol % carbon monoxide, and about 0.1 mol % to about 0.9 mol % carbon dioxide to produce a gas mixture comprising about 10 mol % to about 50 mol % nitrogen, about 55 mol % to about 75 mol % hydrogen, and about 0.5 mol % to about 10 mol % methane;
introducing the gas mixture to a compressor to produce a compressed gas mixture having a pressure of about 1,000 kPa to about 20,800 kPa, wherein the compressed gas mixture has the same composition as the gas mixture entering the compressor;
selectively separating the compressed gas mixture at cryogenic conditions to produce a first gas comprising about 10 mol % to about 40 mol % nitrogen and about 60 mol % to about 90 mol % hydrogen, and a second gas comprising about 5 mol % to about 30 mol % methane, about 1 mol % to about 10 mol % argon, residual hydrogen, and about 40 mol % to about 85 mol % nitrogen; and
reacting at least a portion of the first gas at conditions sufficient to produce an ammonia product.
2. The method of claim 1 , wherein selectively separating all or a portion of the compressed gas mixture at cryogenic conditions comprises:
expanding at least a portion of the compressed gas mixture to produce a cooled gas mixture;
stripping at least a portion of the cooled gas mixture under a reflux to produce a purified gas mixture and a liquefied waste, wherein a first portion of the purified gas mixture is removed to produce the first gas;
expanding at least a portion of the liquefied waste to produce a cooled waste gas; and
condensing a second portion of the purified gas mixture using the cooled waste gas to produce the reflux and a warmed waste gas, and withdrawing at least a portion of the warmed waste gas to produce the second gas.
3. The method of claim 2 , wherein at least a portion of the liquefied waste is expanded to produce mechanical energy.
4. The method of claim 3 , further comprising generating electrical power using the mechanical energy.
5. The method of claim 1 , wherein the hydrogen-to-nitrogen molar ratio of the first gas ranges from about 2.2:1.0 to about 3.2:1.0.
6. The method of claim 1 , further comprising drying at least a portion of the gas mixture prior to compressing the gas mixture.
7. The method of claim 1 , further comprising drying at least a portion of the compressed gas mixture prior to separating the compressed gas mixture.
8. The process of claim 1 , further comprising drying at least a portion of the first gas prior to reacting at least a portion of the first gas at conditions sufficient to produce an ammonia product.
9. The process of claim 1 , wherein the compressed gas mixture is cooled using at least a portion the first gas.
10. The process of claim 1 , wherein the compressed gas mixture is cooled using at least a portion of the second gas.
11. A method for producing ammonia, comprising:
methanating a gas comprising about 4 mol % to about 64 mol % nitrogen, about 35 mol % to about 95 mol % hydrogen, about 0.1 mol % to about 0.9 mol % carbon monoxide, and about 0.1 mol % to about 0.9 mol % carbon dioxide to produce a gas mixture comprising carbon monoxide, carbon dioxide, about 10 mol % to about 50 mol % nitrogen, about 55 mol % to about 75 mol % hydrogen, and about 0.5 mol % to about 10 mol % methane;
introducing the gas mixture to a compressor to produce a compressed gas mixture having a pressure of about 1,000 kPa to about 20,800 kPa, wherein the compressed gas mixture has the same composition as the gas mixture entering the compressor;
selectively separating the compressed gas mixture to produce a first gas having a hydrogen-to-nitrogen molar ratio of from about 2.2:1 to about 3.2:1, and a second gas comprising about 1 mol % to about 10 mol % argon, about 40 mol % to about 85 mol % nitrogen, carbon monoxide, and carbon dioxide, wherein the selective separation occurs at a temperature of from about −200° C. to about 0° C.; and
reacting at least a portion of the first gas at conditions sufficient to produce an ammonia product.
12. The method of claim 11 , wherein selectively separating all or a portion of the compressed expanded gas mixture at cryogenic conditions to produce the first gas comprises:
expanding at least a portion of the compressed gas mixture to produce a cooled gas mixture;
stripping at least a portion of the cooled gas mixture under a reflux to produce a purified gas mixture and a liquefied waste, wherein a first portion of the purified gas mixture is removed to produce the first gas;
expanding at least a portion of the liquefied waste to produce a cooled waste gas; and
condensing a second portion of the purified gas mixture using the cooled waste gas to produce the reflux and a warmed waste gas, and withdrawing at least a portion of the warmed waste gas to produce the second gas.
13. The method of claim 12 , wherein at least a portion of the liquefied waste is expanded to produce mechanical energy.
14. The method of claim 13 , further comprising generating electrical power using the mechanical energy.
15. The method of claim 11 , wherein the compressed gas mixture is cooled using at least a portion the first gas.
16. The method of claim 11 , wherein the compressed gas mixture is cooled using at least a portion of the second gas.
17. The method of claim 11 , further comprising drying at least a portion of the gas mixture prior to compressing the gas mixture.
18. The method of claim 11 , further comprising drying at least a portion of the compressed gas mixture prior to cryogenically separating the compressed gas mixture.
19. The method of claim 1 , further comprising:
converting one or more hydrocarbons in the presence of one or more oxidants and steam, to produce a first mixture comprising carbon dioxide, carbon monoxide, hydrogen, nitrogen, argon, water, and methane;
converting the first mixture in the presence of water, forming a second mixture comprising hydrogen, nitrogen, methane, argon, carbon dioxide and residual carbon monoxide; and
separating at least a portion of the carbon dioxide from the second mixture to provide the gas to be methanated.
20. The method of claim 1 , wherein the compressed gas mixture has a pressure of from about 10,400 kPa to about 20,800 kPa.