Patent Application
20250042734
The present disclosure relates to the technical field of new energy, and particularly to a methane reforming reaction system.
As the consumption of traditional energy increases and the consequent environmental pollution becomes more serious, the renewable energy has increasingly attracted attention of countries and research institutes in the world. Hydrogen gas is an energy source with a very high energy density, and may be prepared by decomposing water which is extremely abundant on the earth, or may be prepared by reforming methane which is abundant in fossil energy source. Therefore, hydrogen gas has increasingly become a research hotspot as a clean energy. As compared to the traditional hydrogen production through water electrolysis and catalytic hydrogen production from chemical raw materials, the hydrogen production through methane reforming chemical reaction system with products separated may use nuclear energy, industrial waste heat or new energy such as solar energy as an energy source, thereby reducing the use of electric energy and fossil energy while obtaining a pure product of carbon dioxide, which is of significant importance for achieving sustainable development of energy.
Taking advantage of the characteristics of reduced Gibbs free energy of the methane reforming reaction at a medium temperature and the fact that hydrogen permeable membrane materials only conduct hydrogen ions, several methods for preparing hydrogen gas through methane reforming with a membrane material have been developed. However, in most of currently used methods, a hydrogen permeable membrane is used at medium and high temperatures to separate hydrogen gas obtained after methane reforming from the system, thereby recovering the hydrogen gas. However, such methods result in a too high concentration of carbon dioxide in the hydrogen permeable membrane tube, which will inhibit further progress of the methane reforming reaction, thereby reducing the conversion of methane. The combined effect of these factors results in limited methane reforming production of methane reforming devices for hydrogen production in prior art, low hydrogen production efficiency, and very low conversion efficiency of the system from thermal energy to chemical energy.
In view of this, the present disclosure provides a methane reforming reaction system to at least partially solve the technical problem.
In an aspect, the present disclosure provides a methane reforming reaction system comprising: a reaction chamber, a hydrogen gas separation chamber and a carbon dioxide separation chamber. The reaction chamber is used for a methane reforming reaction between methane and steam; a hydrogen permeable membrane is provided between the hydrogen gas separation chamber and the reaction chamber, and a first outlet is provided on the hydrogen gas separation chamber for separating hydrogen gas produced in the reaction chamber; a carbon dioxide permeable membrane is provided between the carbon dioxide separation chamber and the reaction chamber, and a second outlet is provided on the carbon dioxide separation chamber for separating carbon dioxide produced in the reaction chamber; wherein the hydrogen gas in the hydrogen gas separation chamber has a chemical potential less than that of the hydrogen gas in the reaction chamber under a chemical equilibrium state of the methane reforming reaction; and the carbon dioxide in the carbon dioxide separation chamber has a chemical potential less than that of the carbon dioxide in the reaction chamber under the chemical equilibrium state of the methane reforming reaction.
According to an embodiment of the present disclosure, the first outlet and the second outlet are arranged to face different directions.
According to an embodiment of the present disclosure, the first outlet is connected to a first vacuum pump; and the second outlet is connected to a second vacuum pump.
According to an embodiment of the present disclosure, the first outlet is connected to an external heat supply device to provide heat to the external heat supply device by combusting the hydrogen gas in the hydrogen gas separation chamber.
According to an embodiment of the present disclosure, both the hydrogen gas separation chamber and the carbon dioxide separation chamber are connected to an inert gas input device.
According to an embodiment of the present disclosure, the hydrogen permeable membrane is provided with a first electric potential at a side close to the hydrogen gas separation chamber, and the hydrogen permeable membrane is provided with a second electric potential at a side close to the reaction chamber; the carbon dioxide permeable membrane is provided with a third electric potential at a side close to the carbon dioxide separation chamber; and the carbon dioxide permeable membrane is provided with a fourth electric potential at a side close to the reaction chamber; wherein the first electric potential is less than the second electric potential; and the third electric potential is less than the fourth electric potential.
According to an embodiment of the present disclosure, a difference ΔV1 between the second electric potential and the first electric potential has a value in a range of 0 V<ΔV1≤500 V; and a difference ΔV2 between the fourth electric potential and the third electric potential has a value in a range of 0 V<ΔV2≤500 V.
According to an embodiment of the present disclosure, a hydrogen gas adsorbing material is provided in the hydrogen gas separation chamber, and a carbon dioxide adsorbing material is provided in the carbon dioxide separation chamber.
According to an embodiment of the present disclosure, the hydrogen gas adsorbing material comprises at least one of activated carbon, graphite nanofibers, and carbon nanotubes; and the carbon dioxide adsorbing material comprises at least one of hydrotalcite and a lithium hydroxide adsorbent.
According to an embodiment of the present disclosure, the hydrogen permeable membrane comprises at least one of: ZrO2—TiO2—Y2O3; palladium; SrCexTm1-xO3-δ where 0≤x≤1 and 0≤δ<3; and SrCeyYb1-yO3-α where 0≤y<1 and 0≤α<3.
According to an embodiment of the present disclosure, the carbon dioxide permeable membrane comprises at least one of a poly(4-methyl-1-pentene) membrane, a poly(4-methyl-1-pentene) membrane, and a carbonate membrane.
According to an embodiment of the present disclosure, the reaction system further comprises a thermal energy supply device for providing energy to the methane reforming reaction in the reaction chamber, wherein the thermal energy of the thermal energy supply device comprises any one of solar energy, nuclear energy and industrial waste heat.
According to an embodiment of the present disclosure, a hydrogen permeable membrane is provided between the reaction chamber and the hydrogen gas separation chamber, and a carbon dioxide permeable membrane is provided between the reaction chamber and the carbon dioxide separation chamber. Through the technical means that the chemical potentials of the gases in the hydrogen gas separation chamber and the carbon dioxide separation chamber are less than the chemical potential of the gas produced in the reaction chamber, simultaneous separation of hydrogen gas and carbon dioxide produced in the reaction chamber is achieved, facilitating the forward progress of the methane reforming reaction, reducing the thermal loss of the high temperature reactive gases of methane and steam, and increasing the methane conversion. Meanwhile, high purity hydrogen gas and high purity carbon dioxide are produced through membrane separation, avoiding carbon monoxide residues caused by industrial production, which is of significant importance in terms of energy and power, medicine, chemical engineering and the like.
1: the reaction chamber; 2: the hydrogen gas separation chamber; 3: the carbon dioxide separation chamber; 4: the hydrogen permeable membrane; 5: the carbon dioxide permeable membrane; 6: the first outlet; 7: the second outlet.
The implementations of the present disclosure will be further described below with reference to the drawings.
The chemical reaction formula of the methane reforming reaction is as shown in Formula (I):
CH4+2H2O=4H2+CO2 (I).
As shown in
According to an embodiment of the present disclosure, the reaction chamber, the hydrogen gas separation chamber, and the carbon dioxide separation chamber may all be configured to have a rectangular shape. The hydrogen gas separation chamber may be disposed above or below the reaction chamber. The carbon dioxide separation chamber may be disposed above or below the reaction chamber. Methane and steam enter into the reaction chamber from the left side. With the progress of the methane reforming reaction, the hydrogen gas produced passes through the hydrogen permeable membrane and enters into the hydrogen gas separation chamber, and the carbon dioxide produced passes through the carbon dioxide permeable membrane and enters into the carbon dioxide separation chamber. With the separation of the products, the forward progress of the methane reforming reaction is continuously facilitated.
According to an embodiment of the present disclosure, as shown in
According to an embodiment of the present disclosure, a hydrogen permeable membrane is provided between the reaction chamber and the hydrogen gas separation chamber, and a carbon dioxide permeable membrane is provided between the reaction chamber and the carbon dioxide separation chamber. Through the technical means that the chemical potentials of the gases in the hydrogen gas separation chamber and the carbon dioxide separation chamber are less than the chemical potential of the gas produced in the reaction chamber, simultaneous separation of hydrogen gas and carbon dioxide produced in the reaction chamber is achieved, facilitating the forward progress of the methane reforming reaction, reducing the thermal loss of the high temperature reactive gases of methane and steam, and increasing the methane conversion.
According to an embodiment of the present disclosure, the methane reforming reaction system separate the products of hydrogen gas and carbon dioxide simultaneously, such that the reaction system device has an increased specific surface area, saving more space, and is convenient to arrange, and may efficiently absorb heat, reducing the thermal loss of the device.
According to an embodiment of the present disclosure, the first outlet and the second outlet are arranged to face different directions.
According to an embodiment of the present disclosure, the first outlet may be disposed at the front end of the hydrogen gas separation chamber, and in this case, the second outlet may be disposed at the back end of the carbon dioxide separation chamber. The first outlet may also be disposed at the back end of the hydrogen gas separation chamber, and in this case, the second outlet may be disposed at the front end of the carbon dioxide separation chamber.
According to an embodiment of the present disclosure, the gas outlet of the hydrogen gas separation chamber and the gas outlet of the carbon dioxide separation chamber are disposed in different directions, which may prevent the blending of hydrogen gas and carbon dioxide during output.
According to an embodiment of the present disclosure, the first outlet is connected to a first vacuum pump; and the second outlet is connected to a second vacuum pump.
According to an embodiment of the present disclosure, the first outlet is connected to a first vacuum pump. Through the first vacuum pump, the hydrogen partial pressure in the hydrogen gas separation chamber is lower than the hydrogen partial pressure in the reaction chamber when the methane reforming reaction reaches a chemical equilibrium at the operating temperature, such that the hydrogen gas in the hydrogen gas separation chamber has a chemical potential less than that of the hydrogen gas in the reaction chamber. The second outlet is connected to a second vacuum pump. Through the second vacuum pump, the carbon dioxide partial pressure in the carbon dioxide separation chamber is lower than the carbon dioxide partial pressure in the reaction chamber when the methane reforming reaction reaches a chemical equilibrium at the operating temperature, such that the carbon dioxide in the carbon dioxide separation chamber has a chemical potential less than that of the carbon dioxide in the reaction chamber.
According to an embodiment of the present disclosure, the hydrogen partial pressure in the hydrogen gas separation chamber and the carbon dioxide partial pressure in the carbon dioxide separation chamber may be controlled at 0.15 bar or less. As compared to the related technologies where it is necessary to control the hydrogen partial pressure in the hydrogen gas separation chamber at 10−3 bar or less for the single separation of hydrogen gas or asynchronous separation of hydrogen gas, the energy consumption of the vacuum pump is lower in the reaction system provided in the embodiment of the present disclosure.
According to an embodiment of the present disclosure, by connecting vacuum pumps respectively at the gas outlets of the hydrogen gas separation chamber and the carbon dioxide separation chamber, the partial pressures of respective gases in the hydrogen gas separation chamber and the carbon dioxide separation chamber are reduced, which facilitates the hydrogen gas produced in the reaction chamber passing through the hydrogen permeable membrane and entering into the hydrogen gas separation chamber and the carbon dioxide passing through the carbon dioxide permeable membrane and entering into the carbon dioxide separation chamber, thereby achieving the purpose of synchronous separation of hydrogen gas and carbon dioxide.
According to an embodiment of the present disclosure, the first outlet is connected to an external heat supply device to provide heat to the external heat supply device by combusting the hydrogen gas in the hydrogen gas separation chamber.
According to an embodiment of the present disclosure, oxygen gas may be used as an oxidative gas. Due to high selectivity of the hydrogen permeable membrane, the hydrogen gas in the hydrogen gas separation chamber has a high purity and may be directly used in industrial applications. The hydrogen gas in the hydrogen gas separation chamber is directly input into the external heat supply device via the first outlet. The external heat supply device is connected to an oxidative gas input device, and the oxidative gas may be oxygen gas. By combusting hydrogen gas and oxygen gas in the hydrogen gas separation chamber, on one hand, the chemical potential of the hydrogen gas in the hydrogen gas separation chamber may be reduced, and on the other hand, heat may be provided to the external heat supply device.
According to an embodiment of the present disclosure, both the hydrogen gas separation chamber and the carbon dioxide separation chamber are connected to an inert gas input device.
According to an embodiment of the present disclosure, the inert gas may comprise helium or argon. By introducing an inert gas into the hydrogen gas separation chamber, the partial pressure of the hydrogen gas in the hydrogen gas separation chamber may be reduced, thereby reducing the chemical potential of the hydrogen gas in the hydrogen gas separation chamber. Introducing an inert gas into the carbon dioxide separation chamber reduces the chemical potential of the carbon dioxide in the carbon dioxide separation chamber, which facilitates the hydrogen gas and the carbon dioxide produced in the reaction chamber entering into the hydrogen gas separation chamber and the carbon dioxide separation chamber respectively, thereby achieving the purpose of synchronous separation.
According to an embodiment of the present disclosure, the hydrogen permeable membrane is provided with a first electric potential at a side close to the hydrogen gas separation chamber, and the hydrogen permeable membrane is provided with a second electric potential at a side close to the reaction chamber; the carbon dioxide permeable membrane is provided with a third electric potential at a side close to the carbon dioxide separation chamber; and the carbon dioxide permeable membrane is provided with a fourth electric potential at a side close to the reaction chamber; wherein the first electric potential is less than the second electric potential; and the third electric potential is less than the fourth electric potential.
According to an embodiment of the present disclosure, by applying different electric potentials respectively at two sides of the hydrogen permeable membrane and two sides of the carbon dioxide permeable membrane, there are electric potential differences between the two sides of the hydrogen permeable membrane and between the two sides of the carbon dioxide permeable membrane, such that chemical potential differences will be generated between the hydrogen gas separation chamber and the reaction chamber, and between the carbon dioxide separation chamber and the reaction chamber, so as to achieve the purpose of synchronous separation of hydrogen gas and carbon dioxide.
According to an embodiment of the present disclosure, a difference ΔV1 between the second electric potential and the first electric potential has a value in a range of 0 V<ΔV1≤500 V; and a difference ΔV2 between the fourth electric potential and the third electric potential has a value in a range of 0 V<ΔV2≤500 V.
According to an embodiment of the present disclosure, the difference ΔV1 between the second electric potential and the first electric potential has a value in a range of 0 V<ΔV1≤500 V, for example, 10 V, 200 V, 350 V, 500 V and the like. The difference ΔV2 between the fourth electric potential and the third electric potential has a value in a range of 0 V<ΔV2≤500 V, for example, 30 V, 210 V, 320 V, 500 V and the like. Here, the difference ΔV1 between the second electric potential and the first electric potential may be the same as or different from the difference ΔV2 between the fourth electric potential and the third electric potential.
According to an embodiment of the present disclosure, a hydrogen gas adsorbing material is provided in the hydrogen gas separation chamber, and a carbon dioxide adsorbing material is provided in the carbon dioxide separation chamber.
According to an embodiment of the present disclosure, a hydrogen gas adsorbing material is provided in the hydrogen gas separation chamber, which may reduce the chemical potential of the hydrogen gas in the hydrogen gas separation chamber, such that the chemical potential of the hydrogen gas in the hydrogen gas separation chamber is less than the chemical potential of the hydrogen gas produced in the reaction chamber. A carbon dioxide adsorbing material is provided in the carbon dioxide separation chamber, which may reduce the chemical potential of the carbon dioxide in the carbon dioxide separation chamber, such that the chemical potential of the carbon dioxide in the carbon dioxide separation chamber is less than the chemical potential of the carbon dioxide produced in the reaction chamber, thereby achieving the purpose of synchronous separation of hydrogen gas and carbon dioxide.
According to an embodiment of the present disclosure, the hydrogen gas adsorbing material comprises at least one of activated carbon, graphite nanofibers, and carbon nanotubes; and the carbon dioxide adsorbing material comprises at least one of hydrotalcite and a lithium hydroxide adsorbent.
According to the embodiment of the present disclosure, the hydrogen gas adsorbing material includes, but not limited to, activated carbon, graphite nanofibers, and carbon nanotubes. Other materials capable of adsorbing hydrogen gas may also be applied in the present disclosure. The carbon dioxide adsorbing material includes, but not limited to, hydrotalcite and a lithium hydroxide adsorbent. Other materials capable of adsorbing carbon dioxide may also be applied in the present disclosure.
According to an embodiment of the present disclosure, the hydrogen permeable membrane comprises at least one of: ZrO2—TiO2—Y2O3; palladium; SrCexTm1-xO3-δ where 0≤x≤1 and 0≤δ<3; and SrCeyYb1-yO3-α where 0≤y≤1 and 0≤α<3.
According to an embodiment of the present disclosure, the carbon dioxide permeable membrane comprises at least one of a polydimethylsiloxane membrane, a poly(4-methyl-1-pentene) membrane, and a carbonate membrane.
According to an embodiment of the present disclosure, the reaction system further comprises a thermal energy supply device for providing energy to the methane reforming reaction in the reaction chamber, wherein the thermal energy of the thermal energy supply device comprises any one of solar energy, nuclear energy and industrial waste heat. The thermal energy may also be provided by combusting other fuels such as methane or by electrical heating.
According to an embodiment of the present disclosure, a Fresnel solar concentrator, a dish solar concentrator or a tower solar concentrator may be used as the thermal energy supply device. The thermal energy may also be provided from nuclear energy or industrial waste heat to reduce the use of electric energy and fossil energy.
According to an embodiment of the present disclosure, the methane reforming reaction system of the present disclosure may be combined with new energy such as solar lamp, nuclear energy, or industrial waste heat, and is clean and environmental friendly.
According to an embodiment of the present disclosure, the methane reforming reaction system of the present disclosure may release thermal energy of other fuels such as methane at a greatly reduced temperature, or convert electric energy to thermal energy, thereby reducing the consumption of other fuels such a methane or electric energy.
According to an embodiment of the present disclosure, the energy efficiencies of the methane reforming reaction system with single separation of hydrogen gas, the methane reforming reaction system with asynchronous separation of hydrogen gas and carbon dioxide, and the methane reforming reaction system with synchronous separation of hydrogen gas and carbon dioxide may be respectively calculated according to the Efficiency Equation (II).
wherein ηpump is the efficiency of the vacuum pump, Wsep is the minimum separation work, and Qheat and ΔH are the energy required for preheating the reactants and the reaction enthalpy change respectively.
As shown in
For the methane reforming reaction at 600° C., in the methane reforming reaction system with single separation of hydrogen gas, when the pressure in the hydrogen gas separation chamber reaches 0.225 bar, the methane conversion may reach 96.6%, and the energy efficiency of the system may reach 40.7%.
In the methane reforming reaction system with asynchronous separation of hydrogen gas and carbon dioxide, as the individual products are separated, the partial pressure within the reactor decreases. When the partial pressures on the inside and outside of the membrane are consistent, the conversion rate no longer increases. Therefore, in the methane reforming reaction system with asynchronous separation of hydrogen gas and carbon dioxide, the pressures in the hydrogen gas separation chamber and carbon dioxide separation chamber should be lower than 0.35 bar to achieve 100% methane conversion rate. However, due to the excessive energy consumption of the vacuum pump, the energy efficiency of the system is reduced.
As shown in
As shown in
In summary, the methane reforming reaction system with simultaneous separation of multiple products according to the embodiments of the present disclosure has a low energy consumption while achieving 100% conversion for the methane reforming reaction.
The particular embodiments of the present disclosure above will not limit the protection scope of the present disclosure. Any of various modifications and variations made according to the technical concept of the present disclosure should be encompassed within the protection scopes of the appended claims of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210113288.8 | Jan 2022 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2023/070442 | 1/4/2023 | WO |
