Method for producing hollow fiber carbon membrane and separation membrane module
An object of the present invention is to provide a method capable of easily controlling the permeation rate and the selectivity of gas molecules, in a hollow fiber carbon membrane which can be used as a gas separation membrane. The present invention provides a method of producing a hollow fiber carbon membrane, the method including: a preparation step of preparing a precursor made of an organic polymer compound in the form of a hollow fiber; a preheating step of heating the precursor to a temperature of 150° C. to 400° C. in an atmosphere containing an oxygen gas; and a carbonization step of heating the precursor which has been subjected to the preheating step to a temperature of 450° C. to 850° C., thereby carbonizing the precursor; wherein the carbonization step includes heating the precursor in the presence of a hydrocarbon gas which may contain a nitrogen atom and which has from 1 to 8 carbon atoms. This method allows for easily controlling the permeation rate and the selectivity of gas molecules, in the resulting hollow fiber carbon membrane.
1. A method of producing a hollow fiber carbon membrane, the method comprising:
a preparation step of preparing a precursor made of an organic polymer compound in the form of a hollow fiber;
a preheating step of heating the precursor to a temperature of 150° C. to 400° C. in an atmosphere containing an oxygen gas; and
a carbonization step of heating the precursor which has been subjected to the preheating step to a temperature of 450° C. to 850° C., thereby carbonizing the precursor;
wherein the carbonization step comprises heating the precursor in the presence of a hydrocarbon gas which may contain a nitrogen atom and which has from 1 to 8 carbon atoms, and the hydrocarbon gas is supplied from an external source.
2. The method of producing a hollow fiber carbon membrane according to claim 1 , wherein the hydrocarbon gas is a hydrocarbon containing a carbon-carbon unsaturated bond.
3. The method of producing a hollow fiber carbon membrane according to claim 1 , wherein the organic polymer compound comprises at least one selected from the group consisting of polyphenylene oxide, and a polyphenylene oxide derivative containing structures represented by the following formulae (a) and (b):
wherein in the formula (b), each R independently represents a hydrogen atom, —SO 3 H, or —SO 3 NH 4 , with the proviso that the Rs are not simultaneously hydrogen atoms.
4. A separation membrane module comprising a hollow fiber carbon membrane produced by the method of producing a hollow fiber carbon membrane according to claim 1 .
5. The method of producing a hollow fiber carbon membrane according to claim 2 , wherein the organic polymer compound comprises at least one selected from the group consisting of polyphenylene oxide, and a polyphenylene oxide derivative containing structures represented by the following formulae (a) and (b):
wherein in the formula (b), each R independently represents a hydrogen atom, —SO 3 H, or —SO 3 NH 4 , with the proviso that the Rs are not simultaneously hydrogen atoms.
6. A separation membrane module comprising a hollow fiber carbon membrane produced by the method of producing a hollow fiber carbon membrane according to claim 2 .
7. A separation membrane module comprising a hollow fiber carbon membrane produced by the method of producing a hollow fiber carbon membrane according to claim 3 .
8. A separation membrane module comprising a hollow fiber carbon membrane produced by the method of producing a hollow fiber carbon membrane according to claim 5 .
9. The method of producing a hollow fiber carbon membrane according to claim 1 , wherein the carbonization step further comprises supplying an inert gas and the hydrocarbon gas simultaneously, and the concentration of the hydrocarbon gas (volume flow rate of hydrocarbon gas/volume flow rate of inert gas×100[% by volume]) is 5% by volume or more, and 50% by volume or less.
10. The method of producing a hollow fiber carbon membrane according to claim 1 , further comprising elevating a temperature within a reactor while supplying an inert gas in the absence of the hydrocarbon gas before starting the carbonization step.
11. The method of producing a hollow fiber carbon membrane according to claim 1 , wherein the hydrocarbon gas has from 1 to 4 carbon atoms.
12. The method of producing a hollow fiber carbon membrane according to claim 2 , wherein the carbonization step further comprises supplying an inert gas and the hydrocarbon gas simultaneously, and the concentration of the hydrocarbon gas (volume flow rate of hydrocarbon gas/volume flow rate of inert gas×100[% by volume]) is 5% by volume or more, and 50% by volume or less.
13. The method of producing a hollow fiber carbon membrane according to claim 2 , further comprising elevating a temperature within a reactor while supplying an inert gas in the absence of the hydrocarbon gas before starting the carbonization step.
14. The method of producing a hollow fiber carbon membrane according to claim 2 , wherein the hydrocarbon gas has from 1 to 4 carbon atoms.
15. The method of producing a hollow fiber carbon membrane according to claim 3 , wherein the carbonization step further comprises supplying an inert gas and the hydrocarbon gas simultaneously, and the concentration of the hydrocarbon gas (volume flow rate of hydrocarbon gas/volume flow rate of inert gas×100[% by volume]) is 5% by volume or more, and 50% by volume or less.
16. The method of producing a hollow fiber carbon membrane according to claim 3 , further comprising elevating a temperature within a reactor while supplying an inert gas in the absence of the hydrocarbon gas before starting the carbonization step.
17. The method of producing a hollow fiber carbon membrane according to claim 3 , wherein the hydrocarbon gas has from 1 to 4 carbon atoms.
18. The method of producing a hollow fiber carbon membrane according to claim 4 , wherein the carbonization step further comprises supplying an inert gas and the hydrocarbon gas simultaneously, and the concentration of the hydrocarbon gas (volume flow rate of hydrocarbon gas/volume flow rate of inert gas×100[% by volume]) is 5% by volume or more, and 50% by volume or less.
19. The method of producing a hollow fiber carbon membrane according to claim 4 , further comprising elevating a temperature within a reactor while supplying an inert gas in the absence of the hydrocarbon gas before starting the carbonization step.
20. The method of producing a hollow fiber carbon membrane according to claim 4 , wherein the hydrocarbon gas has from 1 to 4 carbon atoms.