SYSTEM AND METHOD FOR AMMONIA SYNTHESIS
Systems and methods are disclosed herein for synthesizing ammonia using nano-size metal or metal alloy catalyst particles. Hydrogen and nitrogen gases are passed through a system comprising, for example, a bed of magnetite supporting nano-size iron or iron alloy catalyst particles having an optional oxide layer that forms the catalyst.
1 . A method of synthesizing ammonia comprising reacting a supply of nitrogen gas and hydrogen gas in the presence of nano-sized metal catalyst particles disposed on a ferrous support.
2 . The method of claim 1 , wherein the ferrous support comprises magnetite.
3 . The method of claim 1 , wherein the ferrous material comprises a porous structure.
4 . The method of claim 1 , wherein the ferrous support material comprises a matrix, tubes, granules, a honeycomb, or the like.
5 . The method of claim 2 , further comprising a promoter material on the ferrous support.
6 . The method of claim 5 , wherein at least a portion of the promoter material is selected from the group consisting of aluminum, potassium, calcium, magnesium, and silicon.
7 . The method of claim 1 , wherein the reaction proceeds at a pressure less than about 500 atm.
8 . The method of claim 1 , wherein the reaction proceeds at a pressure less than about 200 atm.
9 . The method of claim 1 , wherein the reaction proceeds at a pressure less than about 100 atm.
10 . The method of claim 1 , wherein the reaction proceeds at a pressure less than about 10 atm.
11 . The method of claim 1 , wherein at least a portion of the nano-sized metal catalyst particles is selected from the group consisting of iron and/or alloys thereof.
12 . The method of claim 11 , wherein at least a portion of the nano-sized metal catalyst particles comprises an iron metal core and an oxide shell.
13 . The method of claim 1 , wherein the nano-sized metal catalyst particles are disposed in a bed.
14 . An ammonia synthesis reactor comprising:
nano-sized iron catalyst particles disposed on a ferrous support material within the reactor;
at least one inlet configured to introduce hydrogen gas and nitrogen gas to the nano-sized metal catalyst particles; and
at least one outlet configured to remove ammonia gas generated in the presence of the nano-sized metal catalyst particles, wherein the reactor is configured to operate at a pressure less than about 500 atm.
15 . The reactor of claim 14 , wherein the ferrous support comprises magnetite.
16 . The reactor of claim 14 , further comprising a promoter material on the ferrous support.
17 . The reactor of claim 16 , wherein at least a portion of the promoter material is selected from the group consisting of aluminum, potassium, calcium, magnesium, and silicon.
18 . The reactor of claim 14 , wherein at least a portion of the nano-sized metal catalyst particles are selected from the group consisting of iron and/or alloys thereof.
19 . The reactor of claim 18 , wherein at least a portion of the nano-sized metal catalyst particles comprises an iron metal core and an oxide shell.
20 . The reactor of claim 14 , wherein the ferrous material comprises a porous structure.
21 . The reactor of claim 14 , wherein the nano-sized metal catalyst particles are disposed in a bed.