Method for producing high purity germane by a continuous or semi-continuous process
View Patent ↗A continuous or semi-continuous process for producing a high purity germane includes (a) preparing a reaction mixture containing hydrogen and crude germane and (b) separating the hydrogen from the crude germane by a pressure swing adsorption process. The pressure swing adsorption process results in a hydrogen-rich product stream and a germane-rich product stream. The method further includes (c) purifying the germane-rich product stream by continuous distillation thereof to remove impurities therefrom and to produce a high purity germane containing less than 0.1 volume percent of impurities.
1. A continuous or semi-continuous process for producing a high purity germane containing less than 0.1 volume percent of impurities, the method comprising:
(a) preparing a reaction mixture containing hydrogen and crude germane;
(b) separating the hydrogen from the crude germane by a pressure swing adsorption process, the pressure swing adsorption process resulting in a hydrogen-rich product stream and a germane-rich product stream; and
(c) purifying the germane-rich product stream by continuous distillation thereof to remove impurities therefrom and to produce a high purity germane containing less than 0.1 volume percent of impurities.
2. The method of claim 1 , wherein the reaction mixture is prepared by contacting a germanium-containing compound with a hydrogen-containing reducing agent.
3. The method of claim 2 , wherein the reducing agent is a borohydride.
4. The method of claim 3 , wherein the germanium-containing compound is germanium dioxide.
5. The method of claim 1 , wherein the pressure swing adsorption process takes place in a vessel including an adsorbent material having a form of a zeolite molecular sieve.
6. The method of claim 5 , wherein the zeolite molecular sieve is a 5 A zeolite molecular sieve.
7. The method of claim 5 , wherein during the pressure swing adsorption process, germane is adsorbed by and desorbed from the zeolite molecular sieve in respective adsorption and desorption stages.
8. The method of claim 7 , wherein the reaction mixture further contains digermane and the digermane is adsorbed by and desorbed from the zeolite molecular sieve in the respective adsorption and desorption stages together with the germane.
9. The method of claim 7 , wherein the pressure of the vessel is maintained at approximately 30 to 250 psia during the adsorption stage and the pressure of the vessel is maintained at approximately 0 to 50 psia during the desorption stage.
10. The method of claim 9 , wherein the temperature of the vessel is generally constant.
11. The method of claim 1 , wherein the continuous distillation of the germane-rich product stream includes passing the germane-rich product stream through a first distillation column to produce a partially purified germane product.
12. The method of claim 11 , wherein the continuous distillation of the germane-rich product stream includes passing the partially purified germane product through a second distillation column to produce the high purity germane.
13. The method of claim 11 , further comprising passing the reaction mixture through a thermal swing adsorption unit prior or subsequent to the pressure swing adsorption process.