Hybrid silica membrane for water removal from lower alcohols and hydrogen separation
A microporous organic-inorganic hybrid membrane based on silica of the invention has an average pore diameter of less than 0.6 nm, and comprises bridging organosilane moieties of the formula ≡O 1.5 Si—CHR—SiO 1.5 ≡ or ≡O 1.5 Si—CH(CH3)—SiO 1.5 ≡. The membrane can be used in the separation of hydrogen from mixtures comprising hydrogen and CH 4 , CO 2 , CO, N 2 , and the like, and in the separation of water from alcohols having 1-3 carbon atoms, optionally in the presence of an inorganic or organic acid.
1. A microporous organic-inorganic hybrid membrane based on silica having an average pore diameter between 0.1 and 0.6 nm, and comprising bridging organosilane moieties of the formula
≡O 1.5 Si—CHR—SiO 1.5 ≡
in which R═H or CH 3 .
2. The microporous organic-inorganic hybrid membrane of claim 1 , wherein a permeance through pores of larger than 0.8 nm is less than 10% of the total permeance through the microporous organic-inorganic hybrid membrane.
3. The microporous organic-inorganic hybrid membrane of claim 1 , wherein microporous organic-inorganic hybrid membrane is adapted to show stable separation performance in a dehydration of methanol, ethanol, propanol, butanol, and their respective isomers at temperature above 100 ° C.
4. The microporous organic-inorganic hybrid membrane of claim 1 , wherein the microporous organic-inorganic hybrid membrane has a thickness at a microporous layer between 20 nm and 2 μm.
5. A composite membrane comprising:
a microporous organic-inorganic hybrid membrane based on silica having an average pore diameter between 0.1 and 0.6 nm, and comprising bridging organosilane moieties of the formula
≡O 1.5 Si—CHR—SiO 1.5 ≡
in which R═H or CH 3 ; and
a mesoporous support which supports the microporous organic-inorganic hybrid membrane.
6. The composite membrane of claim 5 , wherein a permeance through pores of larger than 0.8 nm is less than 10% of the total permeance through the microporous organic-inorganic hybrid membrane.
7. The composite membrane of claim 5 , wherein microporous organic-inorganic hybrid membrane is adapted to show stable separation performance in a dehydration of methanol, ethanol, propanol, butanol, and their respective isomers at temperature above 100 ° C.
8. The composite membrane of claim 5 , wherein the microporous organic-inorganic hybrid membrane has a thickness at a microporous layer between 20 nm and 2 μm.
9. The composite membrane of claim 5 , wherein the mesoporous support is selected from the group consisting of gamma-alumina, titania, zirconia, silica, and hybrid silica.
10. The composite membrane of claim 5 , further comprising a macroporous carrier, wherein the mesoporous support is supported by the macroporous carrier.
11. A method of separating hydrogen from mixtures having hydrogen and at least one gaseous component, the method comprising:
providing a microporous organic-inorganic hybrid membrane based on silica having an average pore diameter between 0.1 and 0.6 nm, and comprising bridging organosilane moieties of the formula
≡O 1.5 Si—CHR—SiO 1.5 ≡
in which R═H or CH 3 ; and then
contacting the mixture and the microporous organic-inorganic hybrid membrane.
12. The method of claim 11 , wherein the at least one gaseous component comprises one of CH 4 , CO 2 , CO, and N 2 .
13. The method of claim 12 , wherein:
providing a microporous organic-inorganic hybrid membrane further comprises supporting the microporous organic-inorganic hybrid membrane on a mesoporous support; and
contacting the mixture and the microporous organic-inorganic hybrid membrane further comprises contacting the mixture and the microporous organic-inorganic hybrid membrane supported by the mesoporous support.
14. A method of separating water from organic molecules, the method comprising:
providing a microporous organic-inorganic hybrid membrane based on silica having an average pore diameter between 0.1 and 0.6 nm, and comprising bridging organosilane moieties of the formula
≡O 1.5 Si—CHR—SiO 1.5 ≡
in which R═H or CH 3 ; and then
contacting the organic molecules and the microporous organic-inorganic hybrid membrane.
15. The method of claim 14 , wherein the organic molecules are at least one alcohol having between 1 to 4 carbon atoms.
16. The method of claim 15 , wherein the organic molecules comprises at least one alcohol having between 1 to 4 carbon atoms, wherein the at least one alcohol is in the presence of one of an inorganic and an organic acid.
17. The method of claim 14 , wherein:
providing a microporous organic-inorganic hybrid membrane further comprises supporting the microporous organic-inorganic hybrid membrane on a mesoporous support; and
contacting the organic molecules and the microporous organic-inorganic hybrid membrane further comprises contacting the organic molecules and the microporous organic-inorganic hybrid membrane supported by the mesoporous support.