CARBON MOLECULAR SIEVE MEMBRANE PREPARED FROM HYDROQUINONE AND THE METHOD OF MANUFACTURING

Abstract

The present invention relates to a method for manufacturing a carbon membrane supported on a ceramic support. The present invention also relates to a carbon membrane prepared from hydroquinone on a ceramic tubular support and to the use of such a membrane. The present invention is focused on the preparation of carbon membranes from hydroquinone oligomer as a thermosetting precursor for gas separation. In an example chemical post treatment of membranes is used for increasing the H.sub.2/CO.sub.2, H.sub.2/N.sub.2 and CO.sub.2/N.sub.2 selectivities.

Claims

1-15. (canceled)

16. A method for manufacturing a carbon membrane supported on a ceramic support from hydroquinone, the method comprising the steps of: a) synthesizing a precursor oligomer by condensing hydroquinone with formaldehyde in aqueous acidic media and heat; b) preparing a dipping solution in an organic solvent; c) coating a ceramic support via dip coating solution obtained in step b); d) drying and polymerizing a top layer of the coated ceramic support obtained in step c); e) carbonizing the polymerized construction obtained in step d); and f) post treating the carbonized construction obtained in step e).

17. The method according to claim 16, further comprising, for multilayer carbon membranes, repeating steps c) to f).

18. The method according to claim 16, wherein the dipping solution comprises the precursor oligomer, formaldehyde, and at least one permeation enhancing component for initiating the polymerization and adding functional groups to the polymer.

19. The method according to claim 16, wherein step b) further comprises synthesizing co-polymer with ethylene diamine or composite polymer with aluminum acetylacetonate.

20. The method according to claim 16, wherein step f) comprises humidifying and oxidizing the carbon membrane with diluted oxygen stream.

21. The method according to claim 16, wherein in step e) the carbonizing temperature is in a range from 500? C. to 1200? C.

22. The method according to claim 16, wherein: one or more layers of coating are applied on the ceramic support; the number of layers is from 1 to 8 layers; and a thickness of each layer is from 300 nm to 20 ?m.

23. The method according to claim 16, wherein the dipping solution in an organic solvent is prepared with reagents including at least one of ethylenediamine, aluminum acetylacetonate, and formaldehyde.

24. The method according to claim 23, wherein hydroquinone oligomers are used as the main precursor, which is mixed or copolymerized with at least one component selected from the group including at least one of polyvinyl butyral (PVB), aluminum acetylacetonate, and ethylene diamine.

25. The method according to claim 16, wherein the ceramic support is selected from the group including at least one of Al.sub.2O.sub.3, ZrO.sub.2, TiO.sub.2, MgO, zeolites, SiO.sub.2, CeO.sub.2, and YSZ porous transition metal oxide tubes.

26. The method according to claim 16, further comprising the step of: g) separating, using the carbon membrane obtained in step f), at least one of H.sub.2 and CO.sub.2 from gas mixtures.

27. The method according to claim 26, wherein the separating process of step g) includes at least one of H.sub.2/CO.sub.2, CO.sub.2/N.sub.2, and H.sub.2/N.sub.2.

28. The method according to claim 26, wherein the separating step g) is used in H.sub.2 separation and purification in H.sub.2 production reactors.

29. The method according to claim 26, wherein the separating step g) is used in H.sub.2 recovery from waste streams associated with metal industry blast furnace off gas treatment and fertilizer production purge.

30. The method according to claim 26, wherein the separating step g) is used in CO.sub.2 separation for at least one of carbon capture and storage, and carbon capture and utilization processes including separating CO.sub.2 from post combustion gas streams or bio syngas purification.

31. The method according to claim 26, further comprising the step of providing the carbon membrane obtained in step f) on a ceramic tubular support

Description

[0040] The invention will now be described by the following non-limiting examples.

[0041] FIG. 1 indicates the permeability of membrane at multiple temperatures.

[0042] FIG. 2 represents the performance of membrane compared to literature upper bound limit for H.sub.2/N.sub.2 separation membranes.

[0043] FIG. 3 represents the H.sub.2 permeability at different operational pressures and temperatures. 8

EXAMPLES

[0044] Table 1 summarizes the fabrication parameters in three developed membranes.

TABLE-US-00001 TABLE 1 fabrication parameters of hydroquinone derived tubular supported carbon membranes. Membrane for H.sub.2/CO.sub.2 H.sub.2/N.sub.2 CO.sub.2/N.sub.2 Support material Al.sub.2O.sub.3 ZrO.sub.2 ZrO.sub.2 Support average pore 100 nm 120 nm 120 nm size Precursor (s) Hydroquinone, Hydroquinone Hydroquinone Polyvinyl oligomer, oligomer, butyral Aluminium ethylene acetylacetonate diamine Number of selective 3 2 2 layers (dippings) Carbonization 500? C. 600? C. 500? C. temperature Carbonization Ar N.sub.2 N.sub.2 atmosphere Selective layer 4.3 ?m 6.7 ?m 3.8 ?m thickness

[0045] An elemental analysis has been performed on the membranes. Results are summarized at Table 2.

TABLE-US-00002 TABLE 2 elemental analysis of hydroquinone derived carbon membranes wt %. Membrane H.sub.2/CO.sub.2 H.sub.2/N.sub.2 CO.sub.2/N.sub.2 N 0 0 1.77 C 85.48 93.56 80.23 H 5.23 2.34 6.14 O 9.29 4.1 11.86

Example 1: H.SUB.2./CO.SUB.2 .Selective Membrane

[0046] H.sub.2/CO.sub.2 high selectivity required in steam reforming reactors to firstly shift the equilibrium to the product side by removing one of the products according to Le-Chatelier's principle and secondly to produce high purity H.sub.2 at the permeate. Hydroquinone oligomer is used as a main precursor for synthesis of H.sub.2/CO.sub.2 selective membrane. Membrane consist of 3 ultra-thin layers, each one of the layers are optimized with fabrication parameters to have high selectivity and preserving high permeability while they stack up onto each other.

[0047] Results of permselectivities tests for H.sub.2/CO.sub.2 membrane are compared to upper bound limits of polymeric membranes. Most cited upper bound limit (Robeson, 2008) and three upper bounds according to operational temperatures (35, 100, 150 and 200? C.) from literature at 2020 indicating the superior performance of H.sub.2/CO.sub.2 selective hydroquinone derived membrane over the organic membranes in terms of both ideal selectivity and H.sub.2 permeability at operational temperatures from 45? C. to 470? C. and operational pressures from 1 to 6 barg.

[0048] Hydroquinone membrane reached maximum ideal H.sub.2/CO.sub.2 selectivity of 43 at 1 bar and 350? C. with H.sub.2 permeability of 12455 Barrer. Membrane chemical and physical stability were tested at 350? C. for a period of 380 hr. at 1 bar operational pressure.

Example 2: CO.SUB.2./N.SUB.2 .Selective Membrane

[0049] CO.sub.2 separation from flue gas in industrial scale requires a minimum CO.sub.2/N.sub.2 selectivity of 70 and a minimum permeance of 3.3?10.sup.?7 mol/(m.sup.2.Math.s.Math.Pa) for being an economically feasible. In case of CO.sub.2/N.sub.2 selective hydroquinone derived carbon membrane, the requirement is validated, and the application of this membrane could have a critical role in industries for separation of CO.sub.2 from flue gas streams such as in metals manufacturing, power plants, and bio refineries.

[0050] Membrane is fabricated on a tubular porous zirconia support with an average pore size of 120 nm. Two ultra-thin selective carbon layers are utilized to reach the desired permselectivities performances. This carbon membrane consist of two selective layers on each other. Upper layer with bigger pore sizes acts as adsorption sites while second layer with smaller average pore size prevents from diffusion of N.sub.2 molecules.

[0051] Transport mechanism in the membrane follows surface diffusion mainly for CO.sub.2. Membrane fabrication is based on condensation polymerization of the oligomer and carbonization at inert atmosphere. FIG. 1 indicates the permeability of membrane at multiple temperatures.

[0052] FIG. 1 indicates the higher performance of CO.sub.2/N.sub.2 selective hydroquinone derived carbon membrane compared to polymeric membranes in operating pressures from 1 to 6 barg and operational temperatures from 45? C. to 470? C.

[0053] CO.sub.2/N.sub.2 selective hydroquinone derived carbon membrane reached the maximum ideal selectivity of 680 at 150? C. and 2 bar pressure difference between permeate and retentate with CO.sub.2 permeability of 1471 Barrer.

Example 3: H.SUB.2./N.SUB.2 .Selective Membrane

[0054] Hydrogen recovery from waste streams in industries such as metal, bio refineries, fertilizers production etc. could increase the efficiency of the processes and reduce the consumption of fresh hydrogen which is mostly produced from fossil fuels and it contributed to greenhouse gas emissions.

[0055] H.sub.2/N.sub.2 selective hydroquinone derived carbon membrane with 2-layer structure is fabricated on a zirconia porous support with average pore size of 120 nm. Performance of the membrane is tested in temperatures from 45? C. to 470? C. and pressures from 1 bar to 6 bar. Membrane is carbonized at 600? C. in N.sub.2 atmosphere. FIG. 2 represents the performance of membrane compared to literature upper bound limit for H.sub.2/N.sub.2 separation membranes.

[0056] H.sub.2/N.sub.2 selective membrane reached maximum ideal selectivity of 302 at 2 bar and 150? C. with hydrogen permeability of 1314 Barrer. FIG. 3 represents the H.sub.2 permeability at different operational pressures and temperatures.