System and method for the production of ammonia

2:

• The system according to claim 1, wherein the second vessel is formed as a jacket around the first vessel.

3:

• The system according to claim 1, further comprising a spacer vessel separating the second vessel from the third vessel, wherein in the first and second operating modes the spacer vessel is maintained under vacuum to minimise heat transfer between the second and third vessels,
• and wherein the system has a third operating mode wherein:
• (iii) in the third operating mode the first vessel is not in fluid communication with the third vessel, the spacer vessel is filled with a fluid, preferably air, to permit heat transfer between the second and third vessels, and ammonia is recovered from the outlet.

4:

• The system according to claim 3, wherein the spacer vessel is formed as a jacket around the second vessel and the third vessel is formed as a jacket around the spacer vessel.

5:

• The system according to claim 4, wherein the second, spacer and third vessels are concentrically arranged in layers around the first vessel.

6:

• The system according to claim 1, wherein, in the first and second operating modes, the third vessel is unheated.

7:

• The system according to claim 1, wherein the first, second and third materials each comprise a metal halide, optionally wherein the metal halide has ammonia molecules absorbed thereon.

8:

• The system according to claim 7, wherein each metal halide is selected from the list consisting of:
• chlorides, bromides and iodides of Cu, Sn, Ni, Sr, Co, Ba, Li, Mn, Ca, Mg, Fe, and Zn, preferably MnCl2, CaCl2, MgCl2, FeCl2, and ZnCl2.

9:

• The system according to claim 1, wherein the first material is selected to store ammonia under the working temperature and pressure of the catalyst in the first vessel.

10:

• The system according to claim 1, wherein the second material is selected to release ammonia when receiving heat from the first vessel.

11:

• The system according to claim 1, wherein the third material is selected to preferentially absorb ammonia released from the first material under the second operating mode.

13:

• A method according to claim 12, wherein the method further comprises ensuring that the first vessel is not in fluid communication with the third vessel, and heating the third vessel to cause the third material to desorb ammonia and recovering ammonia from the outlet.

15:

• The method according to claim 12, wherein the method comprises having the system alternate between the first and second operating modes and, optionally, placing the system in the third operating mode after at least two repetitions of the first and second operating modes.

17:

• A method for temporary heat storage from a cyclical chemical process using the system of claim 16, the method comprising:
• (i) with the system in the first operating mode, performing a heat-producing chemical process in the first vessel, whereby heat passes from the first vessel to the second vessel causing the material to desorb ammonia or water, and then,
• (ii) with the system in the second operating mode, halting the heat-producing chemical process in the first vessel, whereby heat passes from the second vessel to the first vessel and the second material reabsorbs ammonia or water from the reservoir.