Natural gas hydrogen production equipment and method
阅读说明：本技术 一种天然气制氢设备和方法 (Natural gas hydrogen production equipment and method ) 是由 曲顺利 鹿晓斌 郭雷 王江涛 吴青 徐国峰 于 2020-12-18 设计创作，主要内容包括：本发明涉及一种天然气制氢设备和方法,所述天然气制氢设备包括中心传输单元和环绕其设置的催化反应单元；所述催化反应单元从下至上依次设置有重整催化区、冷却区和变换催化区；所述天然气制氢设备的底部设置有助燃气入口；所述中心传输单元的顶部设置有原料气入口；所述天然气制氢的设备内设置有折流板；所述折流板的中心线和所述天然气制氢制氢设备的中心线相重合。本发明中,通过对小型制氢器结构的合理设计,提高了制氢过程中的热效率,制备得到的氢气纯度高,采用自供热系统,避免天然气重整外部热源依赖。(The invention relates to a natural gas hydrogen production device and a method, wherein the natural gas hydrogen production device comprises a central transmission unit and a catalytic reaction unit arranged around the central transmission unit; the catalytic reaction unit is sequentially provided with a reforming catalytic zone, a cooling zone and a shift catalytic zone from bottom to top; the bottom of the natural gas hydrogen production equipment is provided with a combustion-supporting gas inlet; the top of the central transmission unit is provided with a raw material gas inlet; a baffle plate is arranged in the natural gas hydrogen production equipment; the central line of the baffle plate is coincident with the central line of the natural gas hydrogen production and production equipment. According to the invention, through reasonable design of the structure of the small hydrogen production device, the heat efficiency in the hydrogen production process is improved, the purity of the prepared hydrogen is high, and the self-heating system is adopted, so that the dependence of an external heat source for reforming natural gas is avoided.)
1. A natural gas hydrogen plant, characterized in that the natural gas hydrogen plant comprises a central transmission unit and a catalytic reaction unit arranged around it;
the catalytic reaction unit is sequentially provided with a reforming catalytic zone, a cooling zone and a shift catalytic zone from bottom to top;
the bottom of the natural gas hydrogen production equipment is provided with a combustion-supporting gas inlet;
the top of the central transmission unit is provided with a raw material gas inlet;
a baffle plate is arranged in the natural gas hydrogen production equipment;
the central line of the baffle plate is coincident with the central line of the natural gas hydrogen production and production equipment.
2. The natural gas hydrogen plant of claim 1, wherein the cooling region and the shift catalyst region are both tube-in-tube heat exchange structures;
preferably, at least 2 baffles are arranged;
preferably, when 2 baffles are arranged, the first baffle is arranged in the conversion catalysis area, and the second baffle is arranged in the cooling area;
preferably, the area of the baffle plate is 60-70% of the area of a plane perpendicular to the central line of the natural gas hydrogen production device;
preferably, the cooling zone and the shift catalyst zone are connected with the central transmission unit through a heat exchange hole;
preferably, the combustion-supporting gas inlet is provided with an igniter and a combustion nozzle;
preferably, the outer wall of the natural gas hydrogen production equipment is provided with a heat insulation layer.
3. A method for producing hydrogen from natural gas, the method comprising: the raw material gas is preheated and then passes through a combustion-supporting gas combustion area, and then hydrogen-rich gas is obtained through reforming reaction, cooling and conversion catalysis in sequence.
4. The method of claim 3, wherein the feed gas comprises natural gas and steam;
preferably, the volume ratio of the natural gas to the steam in the raw material gas is 1 (1-2.5).
5. The method of claim 3 or 4, wherein the catalyst in the reforming reaction comprises a nickel-based catalyst and/or a nickel-platinum-based catalyst.
6. The method as claimed in any one of claims 3 to 5, wherein the temperature of the reforming reaction is 800-.
7. The method of any of claims 3-6, wherein the cooling is cooling the reformed feedstock;
preferably, the end temperature of the cooling is 450-.
8. The process of any of claims 3-7, wherein the catalyst in the shift catalysis is a carbon monoxide shift catalyst;
preferably, the carbon monoxide shift catalyst comprises a medium shift low shift catalyst.
9. The process according to any one of claims 3 to 8, wherein the temperature of the shift catalysis is 200 ℃ to 500 ℃.
10. The method of any one of claims 3-9, wherein the method comprises: preheating raw material gas, passing the raw material gas through a combustion-supporting gas combustion area, and sequentially carrying out reforming reaction, cooling and conversion catalysis to obtain hydrogen-rich gas;
the volume ratio of the natural gas to the steam in the feed gas is 1 (1-2.5);
the end temperature of the cooling is 450-500 ℃;
the temperature of the shift catalysis is 200-500 ℃.
Technical Field
The invention relates to the field of hydrogen production by reforming natural gas, in particular to natural gas hydrogen production equipment and a method.
Background
Hydrogen energy is a recognized clean energy source and is emerging as a low carbon and zero carbon energy source. Due to the advantages of high energy density and zero carbon emission, hydrogen energy is considered as the most promising fossil fuel substitute in the future, and is always considered as the "ultimate solution" in the field of mobile energy represented by hydrogen fuel cell vehicles.
From the present point of view, the production of hydrogen mainly comprises: hydrogen production by fossil energy, industrial byproduct recovered hydrogen and hydrogen production by water electrolysis. In view of production costs, the former two methods are mainly used to obtain hydrogen at the present stage. For example, WO2017080207a1 discloses a methanol-water reforming hydrogen production machine and a hydrogen production method thereof, wherein the methanol-water reforming hydrogen production machine comprises a methanol-water storage container (1), a delivery pump (2), a frequency converter (3), a heat exchanger (5) and a reformer (4), wherein: the frequency converter (3) is used for converting low-frequency voltage or direct-current voltage into high-frequency voltage required by an electromagnetic coil (421) of the electromagnetic heater (42), the frequency converter (3) is provided with a liquid cooling radiator (31), and the methanol water raw material flows through the liquid cooling radiator (31) in the pumping process of the delivery pump (2), so that heat generated by the frequency converter (3) is taken away by the methanol water raw material; the reformer (4) is provided with a reforming chamber (41), an electromagnetic heater (42) and a hydrogen purification device (43), wherein the electromagnetic heater (42) comprises an electromagnetic coil (421) and a metal magnetized body (422), and the electromagnetic coil (421) can generate a high-frequency magnetic field after high-frequency voltage is input, so that the metal magnetized body (422) generates heat by induction of the magnetic field and provides heat energy for the reforming chamber (41). The frequency converter (3) has low noise, good heat dissipation effect and low energy consumption, and the generated heat can be effectively utilized.
CN105621357A discloses a method for preparing hydrogen by reforming methane, which adopts a moving bed radial flow reactor, wherein the reactor is divided into a fluid feeding channel, a catalyst fixed bed layer, a catalyst moving bed layer and a fluid discharging channel from outside to inside or from inside to outside along the radial direction; the top and the bottom of the reactor are respectively provided with a fluid inlet and a fluid outlet; the fluid feed port is communicated with the fluid feed channel, and the fluid discharge port is communicated with the fluid discharge channel; the top of the catalyst moving bed layer is provided with a moving bed catalyst inlet, and the bottom of the catalyst moving bed layer is provided with a moving bed catalyst outlet; the fluid feeding channel, the catalyst fixed bed layer, the catalyst moving bed layer and the fluid discharging channel are separated by a material with pores, the size of the pores is satisfied that gas can pass through, and catalyst particles cannot pass through; the method for preparing hydrogen by reforming methane simplifies the construction and operation processes of the device, saves energy consumption and is beneficial to realizing continuous reaction and regeneration of production.
However, hydrogen production by fossil energy and hydrogen recovery by industrial byproducts are industrialized devices, the scale of hydrogen production is large, the cost of hydrogen production is low, but the hydrogen production needs to be supplied to peripheral distributed users and transported by trailers or tank cars, the transportation cost is high, and the supply range of hydrogen is limited. At present, the hydrogen energy demonstration application in China mainly surrounds the layout near a hydrogen production place (less than 200 kilometers), hydrogen storage and transportation are mainly in a high-pressure gaseous state mode, and furthermore, the problems that at present, the consumption is small, users with discontinuous gas use still have hydrogen which cannot be conveniently obtained or the purity of the obtained hydrogen is poor and the like are solved.
Disclosure of Invention
In view of the problems in the prior art, the invention aims to provide a natural gas hydrogen production device and a method, which can realize convenient and efficient hydrogen production through the integrated design of the device and can meet the use requirements of less customers.
In order to achieve the purpose, the invention adopts the following technical scheme:
in a first aspect, the present invention provides a natural gas hydrogen plant comprising a central transport unit and a catalytic reaction unit disposed thereabout;
the catalytic reaction unit is sequentially provided with a reforming catalytic zone, a cooling zone and a shift catalytic zone from bottom to top;
the bottom of the natural gas hydrogen production equipment is provided with a combustion-supporting gas inlet;
the top of the central transmission unit is provided with a raw material gas inlet;
a baffle plate is arranged in the natural gas hydrogen production equipment;
the central line of the baffle plate is coincident with the central line of the natural gas hydrogen production and production equipment.
According to the invention, through reasonable design of the structure of the small hydrogen production device, the heat efficiency in the hydrogen production process is improved, the purity of the prepared hydrogen is high, and the self-heating system is adopted, so that the dependence of an external heat source for reforming natural gas is avoided. The waste heat recovery tube nest is embedded in the equipment, recovers heat of high-temperature reformed gas and transformation reaction, is used for preheating raw material gas, realizes gradient utilization of energy, and is high in energy utilization rate.
As a preferable technical scheme of the invention, the cooling zone and the shift catalytic zone are both in a tubular heat exchange structure.
In the invention, the embedded waste heat recovery tube nest is adopted to recover the heat of the high-temperature reformed gas and the conversion reaction, and the waste heat recovery tube nest is used for preheating the raw material gas, thereby realizing the gradient utilization of energy and having high energy utilization rate.
Preferably, there are at least 2 baffles, for example 2, 3, 4, 5, 6 or 7 baffles, but not limited to the values recited, and other values not recited in this range are equally applicable.
Preferably, when the number of the baffles is 2, the first baffle is arranged in the shift catalytic area, and the second baffle is arranged in the cooling area. When more than 2 are provided, the number of the units can be increased by self according to the requirement in each area.
Preferably, the area of the baffle is 60-70% of the area of the plane perpendicular to the center line of the natural gas hydrogen production system, such as 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, or 70%, but not limited to the values listed, and other values not listed in this range are also applicable.
Preferably, the cooling zone and the shift catalyst zone are connected to the central transfer unit by a shift hole.
Preferably, the oxidant gas inlet is provided with an igniter and a combustion nozzle.
Preferably, the outer wall of the natural gas hydrogen production equipment is provided with a heat insulation layer.
In a second aspect, the present invention provides a method for producing hydrogen from natural gas, the method comprising: the raw material gas is preheated and then passes through a combustion-supporting gas combustion area, and then hydrogen is obtained through reforming reaction, cooling and shift catalysis in sequence.
The hydrogen-rich gas obtained by the invention can be purified to obtain pure hydrogen.
As a preferred technical scheme of the invention, the raw material gas comprises natural gas and water vapor.
Preferably, the volume ratio of natural gas to steam in the feed gas is 1 (1-2.5), and may be, for example, 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5, 1:1.6, 1:1.7, 1:1.8, 1:1.9, 1:2, 1:2.1, 1:2.2, 1:2.3, 1:2.4, or 1:2.5, but is not limited to the recited values, and other values not recited in this range are equally applicable.
As a preferred embodiment of the present invention, the catalyst used in the reforming reaction includes a nickel-based catalyst and/or a nickel-platinum-based catalyst, which are commonly used in the art.
In the present invention, the nickel-based catalyst may be Ni/Al2O3Catalyst, Ni/ZrO catalyst, Ni/MgO catalyst, etc
In the present invention, the nickel-platinum-based catalyst may be Ni-Pt/Al2O3Catalysts, Ni-Pt/ZrO catalysts, or Ni-Pt/MgO catalysts, and the like.
In a preferred embodiment of the present invention, the temperature of the reforming reaction is 800-.
As a preferred embodiment of the present invention, the cooling is performed by cooling the reformed material.
Preferably, the cooling end point temperature is 450-.
In a preferred embodiment of the present invention, the catalyst in the shift catalyst is a carbon monoxide shift catalyst.
Preferably, the carbon monoxide shift catalyst comprises a medium shift low shift catalyst.
In the present invention, the carbon monoxide shift catalyst may be Fe2O3-Cr2O3-Al2O3Catalyst and/or CuO-ZnO-Al2O3Catalysts, and the like.
In a preferred embodiment of the present invention, the temperature of the shift catalyst is 200 ℃ to 500 ℃, and may be, for example, 200 ℃, 220 ℃, 240 ℃, 260 ℃, 280 ℃, 300 ℃, 320 ℃, 340 ℃, 360 ℃, 380 ℃, 400 ℃, 420 ℃, 440 ℃, 460 ℃, 480 ℃ or 500 ℃, but is not limited to the above-mentioned values, and other values not listed in the above-mentioned range are also applicable.
As a preferred technical solution of the present invention, the method comprises: preheating raw material gas, passing the raw material gas through a combustion-supporting gas combustion area, and sequentially carrying out reforming reaction, cooling and shift catalysis to obtain hydrogen;
the volume ratio of the natural gas to the steam in the feed gas is 1 (1-2.5);
the end temperature of the cooling is 450-500 ℃;
the temperature of the shift catalysis is 200-500 ℃.
Compared with the prior art, the invention at least has the following beneficial effects:
according to the invention, through reasonable design of the structure of the small hydrogen production device, the heat efficiency in the hydrogen production process is improved, and the hydrogen production equipment completely adopts an automatic heat supply system, so that the dependence of an external heat source for reforming natural gas is avoided. The waste heat recovery shell and tube is embedded in the equipment, the heat of high-temperature reformed gas and transformation reaction is recovered, the waste heat recovery shell and tube is used for preheating the feed gas, the cascade utilization of energy is realized through the coupling of the internal structure of the single equipment, and the energy utilization rate is high. The flow rate of hydrogen in the obtained product can reach above 2520 kmol/L.
Drawings
FIG. 1 is a natural gas hydrogen plant according to an embodiment of the present invention.
In the figure: 1-central transmission unit, 2-shift catalytic zone, 3-cooling zone, 4-reforming catalytic zone, 5-igniter, A-raw gas, B-product and C-combustion-supporting gas.
The present invention is described in further detail below. The following examples are merely illustrative of the present invention and do not represent or limit the scope of the claims, which are defined by the claims.
Detailed Description
To better illustrate the invention and to facilitate the understanding of the technical solutions thereof, typical but non-limiting examples of the invention are as follows:
example 1
The embodiment provides a natural gas hydrogen production device, as shown in fig. 1, the natural gas hydrogen production device includes a central transmission unit 1 and a catalytic reaction unit arranged around the central transmission unit;
the catalytic reaction unit is sequentially provided with a reforming catalytic zone 4, a cooling zone 3 and a shift catalytic zone 2 from bottom to top;
the bottom of the natural gas hydrogen production equipment is provided with a combustion-supporting gas C inlet;
the top of the central transmission unit 1 is provided with a raw material gas A inlet;
a baffle plate is arranged in the natural gas hydrogen production equipment;
the central line of the baffle plate is coincident with the central line of the natural gas hydrogen production and production equipment.
The cooling zone 3 and the shift catalytic zone 2 are both in a tubular heat exchange structure;
the number of the baffle plates is 2, the first baffle plate is arranged in the shift catalytic area 2, and the second baffle plate is arranged in the cooling area 3;
the arrangement area of the baffle plate is 65% of the area of a plane vertical to the central line of the natural gas hydrogen production device;
the cooling zone 3 and the shift catalytic zone 2 are connected with the central transmission unit 1 through heat exchange holes;
the inlet of the combustion-supporting gas C is provided with an igniter 5 and a combustion nozzle;
and the outer wall of the natural gas hydrogen production equipment is provided with a heat insulation layer.
Example 2
The embodiment provides a natural gas hydrogen production device, which comprises a central transmission unit 1 and a catalytic reaction unit arranged around the central transmission unit;
the catalytic reaction unit is sequentially provided with a reforming catalytic zone 4, a cooling zone 3 and a shift catalytic zone 2 from bottom to top;
the bottom of the natural gas hydrogen production equipment is provided with a combustion-supporting gas C inlet;
the top of the central transmission unit 1 is provided with a raw material gas A inlet;
a baffle plate is arranged in the natural gas hydrogen production equipment;
the central line of the baffle plate is coincident with the central line of the natural gas hydrogen production and production equipment.
The cooling zone 3 and the shift catalytic zone 2 are both in a tubular heat exchange structure;
the number of the baffle plates is 2, the first baffle plate is arranged in the shift catalytic area 2, and the second baffle plate is arranged in the cooling area 3;
the arrangement area of the baffle plate is 70% of the area of a plane vertical to the central line of the natural gas hydrogen production device;
the cooling zone 3 and the shift catalytic zone 2 are connected with the central transmission unit 1 through heat exchange holes;
the inlet of the combustion-supporting gas C is provided with an igniter 5 and a combustion nozzle;
and the outer wall of the natural gas hydrogen production equipment is provided with a heat insulation layer.
Example 3
The embodiment provides a natural gas hydrogen production device, which comprises a central transmission unit 1 and a catalytic reaction unit arranged around the central transmission unit;
the catalytic reaction unit is sequentially provided with a reforming catalytic zone 4, a cooling zone 3 and a shift catalytic zone 2 from bottom to top;
the bottom of the natural gas hydrogen production equipment is provided with a combustion-supporting gas C inlet;
the top of the central transmission unit 1 is provided with a raw material gas A inlet;
a baffle plate is arranged in the natural gas hydrogen production equipment;
the central line of the baffle plate is coincident with the central line of the natural gas hydrogen production and production equipment.
The cooling zone 3 and the shift catalytic zone 2 are both in a tubular heat exchange structure;
the number of the baffle plates is 2, the first baffle plate is arranged in the shift catalytic area 2, and the second baffle plate is arranged in the cooling area 3;
the arrangement area of the baffle plate is 60% of the area of a plane vertical to the central line of the natural gas hydrogen production device;
the cooling zone 3 and the shift catalytic zone 2 are connected with the central transmission unit 1 through heat exchange holes;
the inlet of the combustion-supporting gas C is provided with an igniter 5 and a combustion nozzle;
and the outer wall of the natural gas hydrogen production equipment is provided with a heat insulation layer.
Application example 1
The hydrogen production apparatus provided in example 1 was used to produce hydrogen gas, the method comprising: preheating raw material gas, passing the raw material gas through a combustion-supporting gas combustion area, and sequentially carrying out reforming reaction, cooling and shift catalysis to obtain hydrogen;
the volume ratio of the natural gas to the steam in the feed gas is 1: 2.5; the flow rate of the natural gas is 1000kmol/h, and the flow rate of the water vapor is 2500 kmol/h;
the catalyst in the reforming reaction is Ni/Al2O3A catalyst;
the temperature of the reforming reaction is 1000 ℃;
the cooling is to cool the reformed material;
the final temperature of the cooling is 470 ℃;
the catalyst in the shift catalysis is CuO-ZnO-Al2O3A catalyst;
the temperature of the shift catalysis was 250 ℃.
H in the product2：2780kmol/h；CO：80kmol/h；CH4：4kmol/h；CO2：915kmol/h；H2O：1700kmol/h。
Application example 2
The hydrogen production apparatus provided in example 1 was used to produce hydrogen gas, the method comprising: preheating raw material gas, passing the raw material gas through a combustion-supporting gas combustion area, and sequentially carrying out reforming reaction, cooling and shift catalysis to obtain hydrogen;
the volume ratio of the natural gas to the steam in the feed gas is 1: 1; the flow rate of the natural gas is 1000kmol/h, and the flow rate of the water vapor is 1000 kmol/h;
the catalyst in the reforming reaction is Ni/Al2O3A catalyst;
the temperature of the reforming reaction is 800 ℃;
the cooling is to cool the reformed material;
the final temperature of the cooling is 450 ℃;
the catalyst in the shift catalysis is Fe2O3-Cr2O3-Al2O3A catalyst;
the temperature of the shift catalysis was 450 ℃.
H in the product2：2680kmol/h；CO：230kmol/h；CH4：360kmol/h；CO2：410kmol/h；H2O：600kmol/h。
Application example 3
The hydrogen production apparatus provided in example 1 was used to produce hydrogen gas, the method comprising: preheating raw material gas, passing the raw material gas through a combustion-supporting gas combustion area, and sequentially carrying out reforming reaction, cooling and shift catalysis to obtain hydrogen;
the volume ratio of the natural gas to the steam in the feed gas is 1: 1.5; the flow rate of the natural gas is 1000kmol/h, and the flow rate of the water vapor is 1500 kmol/h;
the catalyst in the reforming reaction is Ni/Al2O3A catalyst;
the temperature of the reforming reaction is 900 ℃;
the cooling is to cool the reformed material;
the final temperature of the cooling is 500 ℃;
the catalyst in the shift catalysis is Fe2O3-Cr2O3-Al2O3A catalyst;
the temperature of the shift catalysis was 350 ℃.
H in the product2：2520kmol/h；CO：255kmol/h；CH4：70kmol/h；CO2：675kmol/h；H2O：845kmol/h。
Comparative example 1
The only difference from example 1 is that the volume ratio of natural gas to steam is 1:4, i.e. the steam flow is 4000kmol/L, and the product obtained is H2：2540kmol/h；CO：23kmol/h；CH4：0.6kmol/h；CO2：976kmol/h；H2O: 3494 kmol/h. It is seen that changing the volume ratio results in a decrease in the hydrogen flow rate, while the content of other components increases significantly, so that the quality of the resulting hydrogen-rich gas is deteriorated.
Comparative example 2
The only difference from example 1 is that no cooling zone is provided and that H is present in the product obtained2：2138kmol/h；CO：600kmol/h；CH4：3kmol/h；CO2：397kmol/h；H2O: 2355 kmol/h. When the cooling area is not arranged, the content of hydrogen in the hydrogen-rich gas is obviously reduced, the content of carbon monoxide is obviously improved, and the quality of the hydrogen product is reduced.
Comparative example 3
The only difference from example 1 is that the shift catalyst zone and the central transfer unit are not provided with connecting holes, and H in the resulting product2：2536kmol/h；CO：61kmol/h；CH4：3kmol/h；CO2：936kmol/h；H2O: 1959 kmol/h. When no heat-exchanging holes are providedThe content of carbon dioxide in the obtained product gas is improved, and the content of hydrogen is reduced, so that the quality of the obtained hydrogen-rich gas is reduced.
According to the results of the embodiment and the comparative example, the heat efficiency in the hydrogen production process is improved through the reasonable design of the structure of the small hydrogen producer, and the hydrogen production equipment completely adopts a self-heating system to avoid the dependence of an external heat source for reforming natural gas. The waste heat recovery shell and tube is embedded in the equipment, the heat of high-temperature reformed gas and transformation reaction is recovered, the waste heat recovery shell and tube is used for preheating the feed gas, the cascade utilization of energy is realized through the coupling of the internal structure of the single equipment, and the energy utilization rate is high.
The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.
It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.
In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.