Conversion of ammonia to hydrogen and nitrogen using ammonia as a sweep gas
The disclosure relates to systems and methods for the production of hydrogen (H 2 ) from ammonia (NH 3 ) in a membrane reactor that include using ammonia as a sweep gas. Ammonia is converted to hydrogen and nitrogen (N 2 ), and the hydrogen is separated from the nitrogen and unreacted ammonia by passing the hydrogen through a hydrogen-permeable membrane while using ammonia as a sweep gas. The ammonia sweep gas can be separated from the permeated hydrogen and continuously recycled.
1 . A system, comprising:
a reactor comprising a first portion and a second portion, the first and second portions separated by a hydrogen-permeable membrane;
a first ammonia source configured to be in fluid communication with the first portion of the reactor;
a second ammonia source configured to be in fluid communication with the second portion of reactor; and
a heat source,
wherein the system is configured so that, during use of the system:
the first ammonia source supplies ammonia to the first portion of the reactor;
the heat source heats the ammonia in the first portion of the reactor so that the ammonia in the first portion of the reactor is converted to hydrogen and nitrogen;
the hydrogen passes through the hydrogen-permeable membrane and enters the second portion of the reactor; and
the second ammonia source supplies ammonia to the second portion of the reactor in the form of a gas stream that removes the hydrogen from the second portion of the reactor.
2 . The system of claim 1 , wherein the first ammonia source is the same as the second ammonia source.
3 . The system of claim 1 , further comprising:
a first cylinder comprising the hydrogen-permeable membrane; and
a second cylinder that surrounds the first cylinder.
4 . The system of claim 3 , wherein:
an interior space of the first cylinder defines the first portion of the reactor; and
an annular space formed between an exterior surface of the first cylinder and an interior surface of the second cylinder defines the second portion of the reactor.
5 . The system of claim 3 , wherein:
an interior space of the first cylinder defines the second portion of the reactor; and
an annular space formed between an exterior surface of the first cylinder and an interior surface of the second cylinder defines the first portion of the reactor.
6 . The system of claim 3 , comprising a plurality of first and second cylinders.
7 . The system of claim 1 , further comprising a catalyst disposed in the first portion of the reactor.
8 . The system of claim 1 , wherein the hydrogen-permeable membrane comprises a planar hydrogen-permeable membrane.
9 . The system of claim 1 , further comprising a cooler, a compressor, and a condenser in fluid communication with an outlet of the second portion of the reactor.
10 . The system of claim 9 , further comprising a separator, capable of separating ammonia and hydrogen, in fluid communication with an outlet of the condenser,
wherein the ammonia from the separator forms a third ammonia source.
11 . The system of claim 10 , wherein
the third ammonia source comprises a contaminant; and
the contaminant is removed from the third ammonia source.
12 . The system of claim 11 , wherein the third ammonia source is configured to be in fluid communication with the second portion of reactor.
13 . The system of claim 12 , wherein the third ammonia source supplies ammonia to the second portion of the reactor in the form of a gas stream that removes the hydrogen from the second portion of the reactor.
14 . A system, comprising:
a reactor comprising a first portion and a second portion, the first and second portions separated by a hydrogen-permeable membrane;
a first ammonia source configured to be in fluid communication with the first portion of the reactor;
a second ammonia source configured to be in fluid communication with the second portion of reactor;
a first cylinder comprising the hydrogen-permeable membrane; and
a second cylinder that surrounds the first cylinder.
15 . The system of claim 14 , wherein the first ammonia source is the same as the second ammonia source.
16 . The system of claim 14 , further comprising a cooler, a compressor, and a condenser in fluid communication with an outlet of the second portion of the reactor.
17 . The system of claim 16 , further comprising a separator, capable of separating ammonia and hydrogen, in fluid communication with an outlet of the condenser,
wherein the ammonia from the separator forms a third ammonia source.
18 . A system, comprising:
a reactor comprising a first portion and a second portion, the first and second portions separated by a hydrogen-permeable membrane;
a first ammonia source configured to be in fluid communication with the first portion of the reactor;
a second ammonia source configured to be in fluid communication with the second portion of reactor;
a cooler;
a compressor; and
a condenser in fluid communication with an outlet of the second portion of the reactor.
19 . The system of claim 18 , wherein the first ammonia source is the same as the second ammonia source.