Process for purification of germane
A process and system for the synthesis and/or purification of crude germane to provide a purified germane product are disclosed herein. In one aspect of the present invention, there is provided a process for making a purified germane product containing less than 1 volume percent of one or more germanium-containing impurities comprising: providing a crude germane fluid; passing at least a portion of the crude germane fluid through a first adsorbent which selectively adsorbs water and carbon dioxide contained therein and withdrawing therefrom a partially purified germane fluid; passing at least a portion of the partially purified germane fluid through a second adsorbent which selectively adsorbs the one or more germanium-containing impurities contained therein and withdrawing therefrom a hydrogen-enriched purified germane fluid; and separating the purified germane product hydrogen from the hydrogen-enriched purified germane fluid.
1. A process for making a purified germane product containing less than 1 volume percent of one or more germanium-containing impurities, the process comprising:
providing a crude germane fluid;
passing at least a portion of the crude germane fluid through a first adsorbent which selectively adsorbs water and carbon dioxide contained therein and withdrawing therefrom a partially purified germane fluid;
passing at least a portion of the partially purified germane fluid through a second adsorbent which selectively adsorbs the one or more germanium-containing impurities contained therein and withdrawing therefrom a hydrogen-enriched purified germane fluid; and
separating the purified germane product from the hydrogen-enriched purified germane fluid.
2. The process of claim 1 further comprising cooling the crude germane fluid to at least partially remove water contained therein.
3. The process of claim 1 wherein the providing step comprises contacting a germanium-containing compound with a reducing agent to provide the crude germane fluid.
4. The process of claim 3 wherein the germanium-containing compound is at least one selected from germanium tetrachloride, germanium oxide, a germanide, and elemental germanium.
5. The process of claim 3 wherein the reducing agent is at least one selected from sodium borohydride, potassium borohydride, lithium borohydride, lithium aluminum hydride, sodium aluminum hydride, lithium hydride, sodium hydride, magnesium hydride, calcium hydride, diisobutylaluminum hydride, alkyl aluminum hydride, trialkylaluminum, lithium tri-t-butoxyaluminohydride, sodium dihydrobis(2-methoxyethoxy) aluminate, and mineral acid.
6. The process of claim 1 wherein the providing step comprises an electrochemical reduction of at least one germanium-containing compound.
7. The process of claim 6 wherein the germanium-containing compound is at least one selected from germanium tetrachloride, germanium oxide, a germanide, and elemental germanium.
8. The process of claim 1 wherein the providing step comprises contacting at least one germanium-containing compound with hydrogen atoms.
9. The process of claim 1 wherein the first adsorbent is a molecular sieve selected from 4A (NaA), small pore mordenite, ferrierite, Zeolite F, Zeolite W, a carbon molecular sieve, and combinations thereof.
10. The process of claim 9 wherein the molecular sieve is the 4A molecular sieve.
11. The process of claim 1 wherein the first adsorbent has an effective pore diameter greater than 4 angstroms.
12. The process of claim 1 wherein the second adsorbent has an effective pore diameter greater than 4 angstroms.
13. The process of claim 12 wherein the second adsorbent is a molecular sieve selected from 5A (CaA), 13X (NaX), NaY, NH 4 Y, HY, USY, dealuminated Y, L, lithium LSX, a faujasite structured zeolite, large pore mordenite, chabazite, ZSM-5, beta type, and combinations thereof.
14. The process of claim 12 wherein the molecular sieve is a 13X molecular sieve.
15. The process of claim 1 wherein the second adsorbent comprises an adsorbent selected from silica, alumina, and activated carbon.
16. The process of claim 1 wherein the first and second adsorbents comprise a layered adsorbent.
17. The process of claim 16 wherein the layered adsorbent has a 4A molecular sieve at an inlet end and a 13X molecular sieve at an outlet end.
18. The process of claim 1 wherein the separating step is conducted by one or more methods selected from distillation, recrystallization, evaporation, membrane separation, adsorption, and extraction.
19. A process for making a purified germane product containing less than 1 volume percent of one or more germanium-containing impurities, the process comprising:
contacting a germanium-containing compound with a reducing agent to provide a crude germane fluid comprising germane, germanium-containing impurities, hydrogen, water, and carbon dioxide;
optionally cooling the crude germane fluid to at least partially remove the water contained therein;
passing at least a portion of the crude germane fluid through a first adsorbent which selectively adsorbs water and carbon dioxide and withdrawing therefrom a partially purified germane fluid;
passing at least a portion of the partially purified germane fluid through a second adsorbent which selectively adsorbs the one or more germanium-containing impurities and withdrawing therefrom a hydrogen-enriched purified germane fluid; and
separating the purified germane product from the hydrogen-enriched purified germane fluid.
20. A process for the removal of one or more germanium-containing impurities from a crude germane fluid, the process comprising:
passing at least a portion of the crude germane fluid through a first adsorbent which selectively adsorbs water and carbon dioxide contained therein and withdrawing therefrom a partially purified germane fluid; and
passing at least a portion of the partially purified germane fluid through a second adsorbent which selectively adsorbs the one or more germanium-containing impurities contained therein and withdrawing therefrom a purified germane product wherein an effective pore diameter of the second adsorbent is equal to or greater than an effective pore diameter of the first adsorbent.
21. The process of claim 20 wherein the effective pore diameter of the second adsorbent is greater than the effective pore diameter of the first adsorbent.
22. The process of claim 21 wherein the first adsorbent is a molecular sieve selected from 4A (NaA), small pore mordenite, ferrierite, Zeolite F, Zeolite W, carbon molecular sieve and combinations thereof.
23. The process of claim 22 wherein the molecular sieve is the 4A molecular sieve.
24. The process of claim 21 wherein the second adsorbent is a molecular sieve selected from 5A (CaA), 13X (NaX), NaY, NH 4 Y, HY, USY, dealuminated Y, L, lithium LSX, a faujasite structured zeolite, large pore mordenite, chabazite, ZSM-5, beta type, and combinations thereof.
25. The process of claim 24 wherein the molecular sieve is a 13X molecular sieve.
26. The process of claim 20 wherein the first and second adsorbents comprise a layered adsorbent.
27. The process of claim 26 wherein the layered adsorbent has a 4A molecular sieve at an inlet end and a 13X molecular sieve at an outlet end.