Hydrogen purification by adsorption
A method for purifying a crude hydrogen feed stream utilizes an adsorbent having a N2/Ar selectivity ranging from 2 to 4 at 30° C. and a Henry's law coefficient for argon ranging from 0.15 to 1.0 mmole/g/atma at 30° C. The composition of crude hydrogen streams from processes in which carbon dioxide is captured necessitates new criteria for adsorbent selection to improve recovery.
1 . A method for purifying a crude hydrogen feed stream comprising argon and nitrogen, the method comprising:
feeding the crude hydrogen feed stream to an adsorption apparatus comprising a discharge end adsorption layer comprising a first adsorbent having a N2/Ar selectivity ranging from 2 to 4 at 30° C. and a Henry's law coefficient for argon ranging from 0.15 to 1.0 mmole/g/atma at 30° C.; and
collecting a product gas from the adsorption apparatus.
2 . The method of claim 1 , wherein the product gas comprises less than or equal to 99.95% hydrogen by volume.
3 . The method of claim 1 , wherein the crude hydrogen feed stream comprises more than 90% hydrogen by volume.
4 . The method of claim 1 , wherein the crude hydrogen feed stream comprises more than 1% nitrogen by volume.
5 . The method of claim 1 , wherein the crude hydrogen feed stream comprises more than 0.01% argon by volume.
6 . The method of claim 1 , wherein the crude hydrogen feed stream comprises less than 1% CO by volume.
7 . The method of claim 1 , wherein the adsorption apparatus further comprises a feed end adsorption layer comprising a second adsorbent; wherein the second adsorbent has a Henry's law coefficient for argon greater than 0.3 mmole/g/atma at 30° C.
8 . The method of claim 1 , wherein the first adsorbent has a heat of adsorption of argon ranging from 4 to 5 kcal/mol.
9 . The method of claim 1 , wherein the first adsorbent has a silicon to aluminum ratio ranging from 2.5 to 50.
10 . The method of claim 1 , wherein the first adsorbent is exchanged with greater than or equal to 30% sodium ions.
11 . The method of claim 1 , wherein the first adsorbent comprises a physical mixture of two or more adsorbent materials.
12 . The method of claim 1 , wherein the first adsorbent has pore sizes ranging from 3.3 to 8 Å.
13 . A method for purifying a crude hydrogen feed stream comprising argon and nitrogen, the method comprising:
feeding the crude hydrogen feed stream to an adsorption apparatus comprising a discharge end adsorption layer comprising a first adsorbent having a silicon to aluminum ratio ranging from 2.5 to 50; and
collecting a product gas from the adsorption apparatus;
wherein the first adsorbent is exchanged with greater than or equal to 30% sodium ions.
14 . The method of claim 13 , wherein the first adsorbent has pore sizes ranging from 3.3 to 8 Å.
15 . The method of claim 13 , wherein the product gas comprises less than or equal to 99.95% hydrogen by volume.
16 . The method of claim 13 , wherein the crude hydrogen feed stream comprises more than 90% hydrogen by volume.
17 . A method for purifying a crude hydrogen feed stream comprising argon and nitrogen, the method comprising:
feeding the crude hydrogen feed stream to an adsorption apparatus comprising a discharge end adsorption layer comprising a first adsorbent having a silicon to aluminum ratio ranging from 2.5 to 50; and
collecting a product gas from the adsorption apparatus;
wherein the crude hydrogen feed stream comprises more than 0.01% argon by volume.
18 . A method for purifying a crude hydrogen feed stream comprising argon and nitrogen, the method comprising:
feeding the crude hydrogen feed stream to an adsorption apparatus comprising a discharge end adsorption layer comprising a first adsorbent having a silicon to aluminum ratio ranging from 2.5 to 50; and
collecting a product gas from the adsorption apparatus;
wherein the first adsorbent has a heat of adsorption of argon ranging from 4 to 5 kcal/mol.