JP4238331B2 - Reformed gas supply device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reformed gas supply device for supplying reformed gas to an internal combustion engine, and in particular, to improve the reforming rate when reforming natural gas using engine exhaust gas, The present invention relates to a reformed gas supply device for supplying an engine as a power source such as a generator.
[0002]
[Prior art]
Conventionally, natural gas mainly composed of methane gas to be supplied to engines reacts with natural gas and carbon dioxide to produce hydrogen and carbon monoxide to reform the natural gas, thereby reducing the calorific value of the gas. There was a reformed gas supply device that increased and supplied to the engine.
[0003]
[Problems to be solved by the invention]
By the way, the gas reforming rate by the conventional method is at most about 80 to 90%, and this method has a problem that high thermal efficiency cannot be obtained in terms of fuel consumption.
[0004]
Therefore, the first object of the present invention is to promote reforming reaction even at a low temperature to generate hydrogen gas and carbon monoxide gas, and send the obtained reformed gas to the engine to improve fuel efficiency. It is to provide a feeding device.
[0005]
The second purpose is to selectively absorb the generated hydrogen during the reforming of natural gas, thereby promoting a reaction in the direction of generating hydrogen gas, increasing the reforming rate, and improving the thermal efficiency. It is to provide a feeding device.
[0006]
The third purpose is to supply reformed gas that can increase the energy efficiency of the entire system by using the power obtained by the fuel cell and the power of other energy sources in addition to the engine. Is to provide a device.
[0007]
The fourth object is an environment-friendly reformed gas supply device that can prevent global warming due to the release of carbon dioxide gas by using carbon dioxide contained in engine exhaust gas to increase the reforming rate. Is to provide.
[0008]
[Means for Solving the Problems]
In order to solve the above technical problem, the first invention is to mix and react a container and carbon dioxide gas provided in the container and separated from the introduced methane gas and engine exhaust gas. A methane gas reforming catalyst for producing hydrogen gas and carbon monoxide gas, and a hydrogen gas having in one space an exhaust passage for the methane gas reforming catalyst and the produced carbon monoxide gas to the engine Partitioning the container so that the other space has a discharge path to the engine, and an electrolyte layer sandwiched between electrodes that ionize and permeate the generated hydrogen gas, and a voltage to be applied between the electrodes And a voltage controller to be controlled.
[0009]
Here, the “electrolyte layer sandwiched between the electrodes” has a so-called fuel cell structure. For example, the electrode is preferably formed of a porous material or a catalyst that adsorbs hydrogen on the surface of the electrode. Examples of hydrogen catalysts include platinum and palladium. The electrolyte layer includes an aqueous electrolyte and a solid electrolyte. The voltage controller may be a variable voltage or a fixed voltage.
[0010]
According to the present invention, by providing an electrolyte layer in the reformed gas supply device, the hydrogen gas is ionized and moved, and further discharged from the reformed gas supply device for supply to the engine. Therefore, the reforming rate of methane gas can be increased by promoting the reaction by the catalyst that generates the hydrogen gas. Further, the output of the engine can be made variable by making the voltage variable by the voltage controller.
[0011]
The second invention is to produce hydrogen gas and carbon monoxide gas by mixing and reacting a container and carbon dioxide gas provided in the container and separated from the introduced methane gas and engine exhaust gas. The methane gas reforming catalyst, and the vessel so that the hydrogen gas and carbon monoxide gas discharge passage to the engine is in one space and the oxygen gas introduction passage and the water discharge passage are in the other space. And an electrolyte layer sandwiched between electrodes for partitioning the interior and supplying power obtained by using the hydrogen gas and the introduced oxygen gas to the storage battery.
[0012]
Here, the “electrolyte layer sandwiched between the electrodes” has a so-called fuel cell structure and function. An oxygen catalyst is used on the negative electrode side. Examples of the oxygen catalyst include silver and nickel. According to the present invention, electric power generated by absorbing a part of the hydrogen gas generated by the catalyst by the electrolyte layer is used for charging the storage battery. Therefore, the reforming rate can be increased by shifting the reaction in the direction of further promoting the production of hydrogen gas by the catalyst. Moreover, since it works so as to promote the charging of the storage battery, electric power can be obtained with high efficiency.
[0013]
The third invention is to produce hydrogen gas and carbon monoxide gas by mixing and reacting a container and carbon dioxide gas provided in the container and separated from the introduced methane gas and engine exhaust gas. The methane gas reforming catalyst, the methane gas reforming catalyst and the generated carbon monoxide gas discharge path to the engine in one space, and the hydrogen gas discharge path to the engine in the other space And a first electrolyte layer sandwiched between electrodes that ionize and permeate the generated hydrogen gas, and an exhaust passage for the catalyst and the carbon monoxide gas to the engine. The inside of the container is partitioned so as to have an oxygen gas introduction path and a water discharge path in the other space and introduced with the hydrogen gas. A second electrolyte layer sandwiched between electrodes for supplying electric power obtained by using raw gas to the storage battery, and a voltage controller for controlling a voltage to be applied between the electrodes of the first electrolyte layer. is there.
[0014]
Here, each of the “first electrolyte layer” and the “second electrolyte layer” has a fuel cell structure. The second electrolyte layer also has the function of a fuel cell functionally. According to the present invention, the presence of the first electrolyte layer and the second electrolyte layer eliminates the hydrogen gas generated by the catalyst, so the hydrogen gas generation reaction by the catalyst is promoted, and the methane gas The modification rate can be further increased. At the same time, since the electric power generated by the second electrolyte layer is applied to the charging of the storage battery, highly efficient electric power can be obtained.
[0015]
According to a fourth invention, in any one of the first invention to the third invention, each of the electrolyte layers contains an electrolyte containing phosphoric acid as a main component. Each of the electrolyte layers contains an electrolyte mainly composed of phosphoric acid. Thereby, hydrogen gas can be absorbed and moved, or power can be supplied to the storage battery with high efficiency.
[0016]
According to a fifth invention, in any one of the first to third inventions, the methane gas reforming catalyst is a group VIII metal, group Ib metal, rare earth oxide, alkali metal oxide of the periodic table of elements. And / or a mixture with an alkaline earth metal oxide.
Thereby, a catalyst having a high reforming rate can be obtained.
[0017]
According to a sixth invention, in any one of the first to third inventions, an on-off valve is provided between the discharge passage and the introduction passage. According to the present invention, the reformed gas supply apparatus, and therefore the engine can be stopped and only the motor can be driven. Therefore, when only a small amount of power is required, wasteful fuel consumption is prevented. , Can help improve fuel economy.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
A reformed gas engine-fuel cell hybrid system 10 to which the reformed gas supply device 11 according to the first embodiment of the present invention is applied will be described with reference to FIG. Further, this embodiment does not limit the present invention unless otherwise specified.
[0019]
The system 10 introduces a hydrogen gas and carbon monoxide by introducing a motor 12, an engine 13, a separator 14 for separating carbon dioxide from the exhaust gas of the engine 13, and separated carbon dioxide gas, methane gas, and air. A reformed gas supply device 11 that supplies a reformed gas obtained by generating gas to the engine 13 and a storage battery 15 that drives the motor 12 are provided.
[0020]
The reformed gas supply device 11 is provided in the container 16 and the methane gas reforming for generating hydrogen gas and carbon monoxide gas by mixing and reacting the methane gas and the carbon dioxide. The catalyst 17 is used. The reformed gas supply device 11 is provided in the container 16 and is a first electrolyte layer sandwiched between electrodes 18a and 18b that absorbs, ionizes, and moves the hydrogen gas generated by the catalyst 17. 18 Further, the reformed gas supply device 11 is provided in the container 16 and supplies the storage battery 15 with electric power obtained by using the hydrogen gas generated by the catalyst 17 and the introduced oxygen gas in the air. The second electrolyte layer 19 sandwiched between the electrodes 19a and 19b and the voltage controller 20 for controlling the voltage to be applied between the electrodes 18a and 18b of the first electrolyte layer 18 are provided.
[0021]
The first electrolyte layer 18 is a discharge path 21 of the carbon monoxide gas generated by the methane gas reforming catalyst 17 in the downstream portion of the methane gas reforming catalyst 17 in the container 16 to the engine 13. And the other space 24 having the discharge path 23 for the hydrogen gas to the engine. In addition, the second electrolyte layer 19 has a discharge path 21 to the engine 13 for the carbon monoxide gas generated by the catalyst 17 in the downstream portion of the methane gas reforming catalyst 17 in the container 16. It is partitioned into one space 22 and a third space 27 having the oxygen gas introduction path 25 and the water discharge path 26.
[0022]
Here, the methane gas reforming catalyst 17 is adsorbed on the surface of, for example, honeycomb-shaped ceramics, porous ceramics, or a large number of pellets or tablet-shaped ceramics filled in a partial region of the container 16. It is a thing. As the methane gas reforming catalyst 17, for example, a mixture of a group VIII metal, a group Ib metal, a rare earth oxide, an alkali metal oxide and / or an alkaline earth metal oxide of the periodic table is used.
[0023]
The electrodes 18a, 18b, 19a, 19b of the first electrolyte layer 18 and the second electrolyte layer 19 are porous electrodes that allow hydrogen gas or oxygen gas to pass therethrough. The electrode 18a and the electrode 19a use a catalyst for absorbing hydrogen gas, and the electrode 19b uses a catalyst for absorbing oxygen gas. Each of the first electrolyte layer 18 and the second electrolyte layer 19 has a fuel cell structure. The storage battery 15 supplies power not only to the motor 12 but also to the other power source 28.
[0024]
The reformed gas engine-fuel cell hybrid system 10 further includes a pipe line 29 for supplying exhaust gas from the engine 13 to the separator 14, and the dioxide dioxide separated from the separator 14 to the reformed gas supply device 11. An introduction path 30 for introducing carbon and an introduction path 31 for introducing methane gas into the reformed gas supply device 11 are provided.
[0025]
Subsequently, the operation of the reformed gas engine-fuel cell hybrid system 10 according to the first embodiment will be described.
A mixed gas of hydrogen gas and carbon monoxide gas is supplied to the engine 13 to drive the engine 13. Then, exhaust gas is sent from the engine 13 through the pipe line 29 to the separator 14. Carbon dioxide is separated from the exhaust gas by the separator 14, and the separated carbon dioxide gas is introduced into the container 16 of the reformed gas supply device 11 through the introduction path 30. The remaining exhaust gas from which the carbon dioxide has been separated is discharged outward from the pipe line 29a. Further, methane gas is introduced into the reformed gas supply device 11 through the introduction path 31. The methane gas and carbon dioxide are introduced into the methane gas reforming catalyst 17 provided in the vessel 16 and mixed and reacted to produce hydrogen gas and carbon monoxide gas.
[0026]
Of the generated hydrogen gas and carbon monoxide gas, hydrogen gas is absorbed by the electrodes 18 a and 19 a of the first electrolyte layer 18 and the second electrolyte layer 19. In the first electrolyte layer 18, hydrogen molecules are ionized in the electrode 18a, and the ionized hydrogen atoms are transferred from the electrode 18a charged in the positive electrode to the electrode 18b charged in the negative electrode. It moves at a moving speed based on the voltage applied between 18b. The ionized hydrogen atoms take in electrons at the electrode 18b and bond as hydrogen molecules, pass through the permeable electrode 18b, and are generated as hydrogen gas. The generated hydrogen gas is supplied to the engine 13 through the discharge path 23.
[0027]
On the other hand, in the second electrolyte layer 19, the hydrogen gas generated by the catalyst 17 is absorbed by the electrode 19 a of the positive electrode and ionized to give the next reaction as in the fuel cell that gives the electron e to the electrode. To do.
^{_{H 2 + 2OH - → 2H 2}} O + 2e -
Further, in the negative electrode 19b, oxygen gas contained in the air introduced from the introduction path 25 is absorbed, and the next reaction similar to that of the fuel cell proceeds by the electrons given from the electrode 19b.
_{O 2 + H 2 O + 2e} - → HO 2 - + OH -
^{_{HO 2 - → OH - + 1}} / 2O 2
[0028]
Thus, the obtained electric power is supplied to the storage battery 15 to charge the storage battery 15, and the power efficiency of the storage battery 15 is increased. The water generated by the reaction of the second electrolyte layer 19 is discharged from the reformed gas supply device 11 through the discharge path 26.
[0029]
In this way, the hydrogen gas generated by the catalyst 17 is selectively excluded from the container 16 by the first electrolyte layer 18 and the second electrolyte layer 19, so that the hydrogen gas is generated. Therefore, the reaction by the catalyst 17 is promoted. Thus, the reaction is promoted in the direction of increasing the reforming rate of methane gas by the catalyst 17.
[0030]
Next, the operation of the reformed gas engine / fuel cell hybrid system 10 according to the first embodiment of the present invention will be described with reference to the following examples based on specific numerical values.
[0031]
According to experiments, the enthalpy increases and decreases obtained by the following chemical reactions are as follows.
CH ₄ + 2O ₂ → CO ₂ + 2H ₂ O ΔH = -191.2kcal / mol… (1)
CO + 0.5O ₂ → CO ₂ ΔH = -67.65kcal / mol… (2)
H ₂ + 0.5O ₂ → H ₂ O ΔH = -57.78kcal / mol… (3)
(A) Therefore, the power obtained when 1 mol of methane gas is directly burned by the engine 13 is 76.48 kcal / mol from the formula (1) × 0.4 when the efficiency of the engine 13 is 40%. .
[0032]
(B) If the methane gas is 85% reformed into carbon monoxide gas and hydrogen gas and burned by the engine 13, the power obtained when the engine efficiency is 40%, the formula (1 ) X (1-0.85) x 0.4 is 11.472 kcal / mol.For carbon monoxide gas, the formula (2) x 0.85 x 2 x 0.4 is 46.002 kcal / mol, and for hydrogen gas, the formula (3 ) Since it is 39.2904 kcal / mol from × 0.85 × 2 × 0.4, the overall power is 96.7644 kcal / mol. Therefore, in the case of (B), the thermal efficiency of 1.27 times is obtained compared to the case of (A).
[0033]
(C) Further, in the case where the present embodiment is used and methane gas is reformed by 95% into carbon monoxide and hydrogen and combusted in the engine, the engine efficiency is set to 40% and the obtained power The size will be described.
For methane gas, it is 3.824 kcal / mol according to the formula (1) x (1-0.95) x 0.4, and for carbon monoxide gas, it is 51.414 kcal / mol according to the formula (2) x 0.95 x 2 x 0.4 The hydrogen gas is 43.9128 kcal / mol according to the formula (3) × 0.95 × 2 × 0.4, and the total power obtained is 99.1508 kcal / mol. In this case, 1.96428 times as much power as in the case of A can be obtained. Compared with B, 1.025 times as much power can be obtained.
[0034]
FIG. 2 shows a reformed gas engine-fuel cell hybrid system 50 according to the second embodiment. In FIG. 2, the same numbers as those in FIG. 1 are omitted for simplicity.
[0035]
In the system 50, unlike the reforming engine-fuel cell hybrid system 10 according to the first embodiment, the introduction paths 25, 30, 31, and the discharge paths 21 connected to the reformed gas supply device 11 are used. , 23, 26 are provided with on-off valves 32, 33, 34, 35, 36, 37.
[0036]
As a result, when a small amount of power is required, the engine 13 is stopped and the power of only the motor 12 is transmitted to the outside through the power transmission system. Therefore, according to the present embodiment, fuel consumption can be further reduced.
[0037]
The above embodiment has been specifically described for better understanding of the present invention, and does not limit other embodiments. Therefore, changes can be made without changing the gist of the invention. For example, in the above description, the case where the reformed gas supply device is provided with the first electrolyte layer and the second electrolyte layer has been described. However, the present invention is not limited to this case, and only the first electrolyte layer is provided. Alternatively, only the second electrolyte layer may be provided. Furthermore, although the system provided with both the motor and the engine has been described, a system only with the engine may be used. Further, although a voltage controller is used, a direct current power source can also be used. Furthermore, although the discharge path 21 and the discharge path 23 are merged in front of the engine, a structure that mixes inside the engine may be used.
[0038]
【The invention's effect】
As described above, according to the first invention, by providing a structure like a fuel cell having an electrolyte layer sandwiched between electrodes in the reformed gas supply device, the hydrogen gas is absorbed and the hydrogen gas And promote the reaction in the direction of producing carbon monoxide gas. Thereby, the reforming rate of methane gas can be increased and the thermal efficiency can be improved.
[0039]
Further, according to the second invention or the third invention, as in the first invention, a structure or function like a fuel cell having an electrolyte layer sandwiched between electrodes is provided in the reformed gas supply device. Thus, the reforming rate of methane gas can be further increased by promoting the reaction in the direction of absorbing hydrogen gas and generating hydrogen gas and carbon monoxide gas. Furthermore, since electric power generated by the absorption of the hydrogen gas can be supplied to a storage battery or the like, highly efficient electric power can be obtained.
[0040]
According to the fourth invention, since phosphoric acid is used as the electrolyte layer, operation is possible even at a low temperature, so that the reforming reaction can be promoted even at a low temperature and the reforming rate can be improved. .
According to the fifth aspect, since the carbon dioxide has a property of promoting absorption, the reforming rate can be further increased.
[0041]
According to the sixth invention, since the engine can be stopped by providing the on-off valve, when only a small power is required, other power having a small power compared to the engine such as a motor. By using the engine, it is possible to prevent unnecessary fuel consumption and to improve fuel consumption.
[Brief description of the drawings]
FIG. 1 is a schematic system diagram of a reformed gas supply apparatus in a first embodiment of the present invention.
FIG. 2 is a schematic system diagram of a reformed gas supply apparatus according to a second embodiment of the present invention.
[Explanation of symbols]
11 Reformed gas supply device 12 Motor 13 Engine 14 Separator 15 Storage battery

Claims (6)

A methane gas reforming catalyst for producing hydrogen gas and carbon monoxide gas by mixing and reacting a vessel and carbon dioxide gas separated from the introduced methane gas and engine exhaust gas, which is provided in the vessel And the container so that the methane gas reforming catalyst and the generated carbon monoxide gas discharge path to the engine are in one space and the hydrogen gas discharge path to the engine is in the other space. And an electrolyte layer sandwiched between electrodes that ionize and permeate the generated hydrogen gas, and a voltage controller that controls a voltage to be applied between the electrodes. Quality gas supply device. A methane gas reforming catalyst for producing hydrogen gas and carbon monoxide gas by mixing and reacting a vessel and carbon dioxide gas separated from the introduced methane gas and engine exhaust gas, which is provided in the vessel And partitioning the container so that the hydrogen gas and carbon monoxide gas discharge passage to the engine is provided in one space and the oxygen gas introduction passage and water discharge passage are provided in the other space. A reformed gas supply apparatus comprising an electrolyte layer sandwiched between electrodes that supply gas and electric power obtained using the introduced oxygen gas to a storage battery. A methane gas reforming catalyst for producing hydrogen gas and carbon monoxide gas by mixing and reacting a vessel and carbon dioxide gas separated from the introduced methane gas and engine exhaust gas, which is provided in the vessel And the container so that the methane gas reforming catalyst and the generated carbon monoxide gas discharge path to the engine are in one space and the hydrogen gas discharge path to the engine is in the other space. One space has a first electrolyte layer sandwiched between electrodes for partitioning the inside and allowing the generated hydrogen gas to be ionized and permeated, and an exhaust passage for the catalyst and the carbon monoxide gas to the engine. And partitioning the container so as to have an oxygen gas introduction path and a water discharge path in the other space, and using the hydrogen gas and the introduced oxygen gas It has the 2nd electrolyte layer pinched by the electrode which supplies the obtained electric power to a storage battery, and the voltage controller which controls the voltage which should be impressed between the electrodes of the 1st electrolyte layer, It is characterized by the above-mentioned. A reformed gas supply device. The reformed gas supply device according to any one of claims 1 to 3, wherein each of the electrolyte layers contains an electrolyte mainly composed of phosphoric acid. The methane gas reforming catalyst is a mixture of a group VIII metal, a group lb metal, a rare earth oxide, an alkali metal oxide and / or an alkaline earth metal oxide of the periodic table of elements. The reformed gas supply apparatus according to any one of claims 1 to 3. The reformed gas supply apparatus according to any one of claims 1 to 3, wherein an on-off valve is provided between the discharge path and the introduction path.

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