Gas generator and gas utilization system

Abstract

The present invention provides a gas generator and gas utilization system that continuously generates gas from metal hydride powder. [Solution] A gas generator and gas utilization system comprising: a reaction vessel having a stirrer for mixing metal hydride powder and a reaction liquid to obtain generated gas; a powder supply mechanism connected to a powder supply passage for supplying the powder to the reaction vessel through the powder supply passage; and a pressurized gas supply mechanism for continuously supplying the powder to the reaction vessel by continuously supplying pressurized gas to the powder supply passage.

Description

Technical Field

[0001] The present disclosure relates to a gas generator and a gas utilization system.

Background Art

[0002] Since metal hydrides can generate gas by hydrolysis or thermal decomposition, they are used to obtain gas. For example, Patent Document 1 discloses a hydrogen gas generator using a slurry containing reaction water, a metal hydride, and a solvent. Since the metal hydride reacts with water, in the technique described in Patent Document 1, a slurry in which a solvent having non-reactivity with respect to the metal hydride and the metal hydride are mixed is used as a raw material.

[0003] In addition, an apparatus for obtaining a mixture using powder and liquid has been developed. Patent Document 2 discloses a dispersion apparatus for mixing powder such as an electrode material of a secondary battery and liquid in particular.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the apparatus described in Patent Document 1, it is necessary to pre-mix the powder and the solvent, and furthermore, the obtained gas contains not only hydrogen gas but also the volatilized solvent. Furthermore, the apparatus described in Patent Document 2 is simply an apparatus for mixing powder and liquid to disperse the powder in the liquid. The technology described in Patent Document 2 focuses on suppressing the deterioration of the powder and the generation of harmful gases caused by the reaction of powder and water, and does not consider the perspective of continuously obtaining useful gases from the powder and liquid.

[0006] This disclosure has been made in view of the above, and the problem that the embodiments of this disclosure aim to solve is to provide a gas generator and a gas utilization system that continuously generates gas from a powder of metal hydride. [Means for solving the problem]

[0007] This disclosure includes the following aspects: <1> A reaction vessel equipped with a stirrer, which mixes metal hydride powder and reaction solution to obtain generated gas, A powder supply mechanism is connected to a powder supply path and supplies the powder to the reaction vessel through the powder supply path. A pressurized gas supply mechanism that continuously supplies the powder to the reaction vessel by continuously supplying pressurized gas to the powder supply path, A gas generator equipped with the following features. <2> The above powder supply mechanism includes a feeder connected to the powder supply path, a first container connected to the feeder, and a second container connected to the first container. The second container stores the powder and supplies it to the first container, and the first container supplies the powder to the feeder, thereby sending the powder from the feeder to the powder supply path. <1> The gas generator described above. <3> The gas produced above is hydrogen gas. <1> or <2> The gas generator described above. <4> The above metal hydride includes at least one selected from the group consisting of lithium hydride, beryllium hydride, sodium hydride, lithium sodium hydride, sodium borohydride, magnesium hydride, aluminum hydride, silicon hydride, potassium hydride, calcium hydride, rubidium hydride, strontium hydride, and barium hydride. <1> ~ <3> A gas generator as described in any one of the following. <5> The system further comprises a reaction liquid storage section for storing the above-mentioned reaction liquid, and a reaction liquid supply passage connected to the reaction liquid storage section for supplying the reaction liquid to the reaction vessel, The reaction liquid supplied through the above reaction liquid supply channel flows down along the inner wall surface of the reaction vessel. <1> ~ <4> A gas generator as described in any one of the following. <6> The average residence time of the powder in the reaction vessel is set to the time required for the reaction between the powder and the reaction liquid. <1> ~ <5> A gas generator as described in any one of the following. <7> The above average residence time τ satisfies 4 / k ≤ τ ≤ 99 / k. <6> The gas generator described above. <8> The agitator stirs the mixture of the powder and the reaction liquid from the bottom to the top of the reaction vessel, and at least one of the group consisting of hydrogenated powder and dehydrogenated powder is discharged to the outside of the reaction vessel through the waste liquid discharge channel. <1> ~ <7> A gas generator as described in any one of the following. <9> The reaction vessel is installed in a heat-utilizing plant and is heated by the plant's waste heat. <1> ~ <8> A gas generator as described in any one of the following. <10> The above reaction vessel is heated by electromagnetic waves. <1> ~ <9> A gas generator as described in any one of the following. <11> <1> ~ <10> A gas generator described in any one of the following, The gas utilization device comprises a gas utilization device to which the generated gas obtained from the gas generator is supplied, A gas utilization system comprising the above-mentioned gas generator and the above-mentioned pressurized gas, which includes at least one selected from the group consisting of hydrogen gas and methane gas. <12> The above-mentioned gas utilization device is a power generation device, a methanation device, a hydrogen bacteria culture device, or a synthesis device for synthesizing organic matter from carbon dioxide and hydrogen. <11> The gas utilization system described above. [Effects of the Invention]

[0008] According to one embodiment of the present disclosure, a gas generator and a gas utilization system are provided for continuously generating gas from a powder of a metal hydride. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of the gas utilization system of the present disclosure, which includes the gas generator of the present disclosure. [Figure 2] Figure 2 is a schematic diagram showing one embodiment of the internal structure of the feeder. [Modes for carrying out the invention]

[0010] One embodiment of this disclosure is described in detail below. However, this disclosure is not limited to the embodiment described below. In the following disclosure, the components (including elemental steps, etc.) are not essential unless otherwise explicitly stated. The same applies to numerical values ​​and their ranges, and they do not limit this disclosure.

[0011] In this disclosure, the numerical range indicated using "~" includes the numbers before and after "~" as the lower and upper limits, respectively. In numerical ranges described in stages within this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described within this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. In this disclosure, the content of each component in the composition means the total content of the multiple substances present in the composition, unless otherwise specified, if multiple substances corresponding to each component are present in the composition. In the present disclosure, when a plurality of elements are listed using "or" or "alternatively", unless otherwise specified, the selection of combinations of the plurality of elements is not excluded as long as there is no technical contradiction. In the present disclosure, even when an element is described in the singular form, unless otherwise specified, the existence of a plurality is not excluded as long as there is no technical contradiction. In the present disclosure, a plurality of exemplary embodiments described separately may be combined with each other to form a new embodiment as long as they do not contradict each other. In the present disclosure, when an embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Also, the sizes of the members in each figure are conceptual, and the relative size relationships between the members are not limited thereto.

[0012] ≪Gas Generator≫ The gas generator of the present disclosure has a stirrer, and a reaction vessel that mixes a powder of a metal hydride and a reaction liquid to obtain a generated gas, a powder supply mechanism to which a powder supply path is connected and that supplies the powder to the reaction vessel through the powder supply path, and a pressurized gas supply mechanism that continuously supplies the powder to the reaction vessel by continuously supplying a pressurized gas to the powder supply path.

[0013] According to the gas generator of the present disclosure, gas can be continuously generated from a powder of a metal hydride. Hereinafter, an embodiment of the gas generator of the present disclosure will be described with reference to FIG. 1. Note that FIG. 1 is a diagram for illustrative purposes and does not limit the embodiments of the present disclosure. As shown in FIG. 1, a gas generator 10, which is an embodiment of the gas generator of the present disclosure, includes a reaction vessel 20, a powder supply mechanism 30, and a pressurized gas supply mechanism 40. The reaction vessel 20 has a stirrer 21 and mixes a powder P of a metal hydride and a reaction liquid L to generate a generated gas. The powder supply mechanism 30 is connected to a powder supply passage 31 and supplies the powder P to the reaction vessel 20 through the powder supply passage 31. The pressurized gas supply mechanism 40 continuously supplies the powder P to the reaction vessel 20 by continuously supplying pressurized gas to the powder supply passage 31. In this disclosure, "continuously implemented" means not only that there is no interruption in implementation, but also that the continuous implementation period includes periods of partial intermittent implementation, to the extent that it does not affect the effects. "Partially intermittently performed" means, for example, stopping the supply of powder P and reaction liquid L and the discharge of waste liquid for a certain period of time to generate generated gas from the mixture M remaining in the reaction vessel 20, and then restarting the supply of powder P and reaction liquid L and the discharge of waste liquid to generate generated gas again, and repeating this operation. "Continuously" means that the implementation is uninterrupted, but also includes variations in the degree of implementation (for example, the amount of powder P and reaction liquid L supplied or the amount of waste liquid discharged) over time.

[0014] Since metal hydrides react with water, if the powder supply mechanism 30 simply supplies powder P to the reaction vessel 20 through the powder supply channel 31, water originating from the mixed liquid M in the reaction vessel 20 may backflow and enter the powder supply mechanism 30 and the powder supply channel 31. The mixed liquid M is a mixture of powder P and reaction liquid L. Examples of water originating from the mixed liquid M include liquid water and gaseous water vapor. If water enters the powder supply mechanism 30 and the powder supply passage 31, the powder P present in the powder supply mechanism 30 and the powder supply passage 31 reacts with the water, causing the powder P to change in quality or solidify into clumps that adhere to the inner walls of the powder supply mechanism 30 and the powder supply passage 31. This can then lead to a chain reaction where more powder P adheres to the clumps of powder P, easily causing blockage of the powder supply mechanism 30 and the powder supply passage 31. Furthermore, if the solidified clumps of powder P unexpectedly fall into the reaction vessel 20, it can lead to poor concentration control. Furthermore, if water enters the powder supply mechanism 30 and the powder supply passage 31, gas may be generated in the powder supply mechanism 30 and the powder supply passage 31, making it difficult to control the gas generation reaction and potentially reducing productivity. Therefore, simply supplying powder P to the reaction vessel 20 through the powder supply passage 31 by the powder supply mechanism 30 is not sufficient to continuously obtain generated gas from the powder P and the reaction liquid L.

[0015] On the other hand, the gas generator 10, which is one embodiment of the gas generator of the present disclosure, is equipped with a pressurized gas supply mechanism 40, which continuously supplies pressurized gas to the powder supply passage 31. The supply of pressurized gas prevents water from entering the powder supply mechanism 30 and the powder supply passage 31, and furthermore, it enables the continuous supply of powder P so as to push it into the reaction vessel 20. As described above, the gas generator of this disclosure can continuously generate gas from metal hydride powder P. From the viewpoint of mass production, reduction of production time, and ensuring product homogeneity, it is desirable to produce gas continuously rather than in batches. In other words, the gas generator of this disclosure is particularly suitable for mass production of gas for stationary use in factories and the like. The gas generator of this disclosure is, for example, a continuous tank reactor (CSTR).

[0016] The generated gas is preferably at least one selected from the group consisting of flammable gases (e.g., hydrogen gas, methane gas, and acetylene gas), combustion-supporting gases (e.g., oxygen gas and chlorine gas), inert gases (e.g., carbon dioxide gas and nitrogen gas), and toxic gases (e.g., chlorine gas, ammonia gas), more preferably a flammable gas, and even more preferably hydrogen gas.

[0017] <Reaction vessel> The reaction vessel 20 has, for example, a wide cylindrical shape, and a powder supply passage 31 is connected to the gas phase portion of the reaction vessel 20 to supply powder P from the powder supply mechanism 30. In the reaction vessel 20, the powder P and the reaction liquid L are mixed and reacted to generate gas.

[0018] The reaction vessel 20 has a stirrer 21. The stirrer 21 has a stirring blade. The agitator 21 mixes the reaction liquid L and powder P to prepare the mixed liquid M by rotating its blades at a set rotational speed. The rotational speed may be constant, or it may be controlled as appropriate depending on the reaction state of the mixed liquid M.

[0019] The reaction vessel 20 may have a stirring bar and a stirring stand (neither of which are shown in the figure) as a stirrer. The stirring bar is elongated and cocoon-like in shape, with both ends rounded and the middle part slightly bulging. A magnet is built into the stirring bar. The stirring bar is placed in the mixed liquid M. The stirring stand, which is provided so as to be in contact with the bottom surface of the reaction vessel 20, generates a magnetic force to rotate the stirring bar. The bottom surface is the surface below in the vertical direction. The stirring stand mixes the reaction liquid L and powder P to prepare the mixture M by rotating the stirring bar at a set rotation speed. The rotation speed may be constant, or it may be controlled as appropriate depending on the reaction state of the mixture M.

[0020] The agitator 21 stirs the mixture M, which is a mixture of powder P and reaction liquid L, from the bottom to the top of the reaction vessel 20, and at least one of the group consisting of hydrogenated powder P (i.e., unreacted powder P) and dehydrogenated powder P (i.e., powder P after reaction) is discharged to the outside of the reaction vessel 20 through the waste liquid discharge channel 23. By stirring the mixture M while stirring it upward, the remaining dehydrogenated powder P is less likely to remain on the bottom of the reaction vessel 20, and the gas generation reaction by more unreacted hydrogenated powder P is more likely to occur in the reaction vessel 20. The hydrogenated powder P and dehydrogenated powder P discharged to the outside of the reaction vessel 20 through the waste liquid discharge channel 23 may be recycled and supplied again to the powder supply mechanism 30. Furthermore, "from the bottom surface to the top surface of the reaction vessel 20" means from the lower surface to the upper surface of the reaction vessel 20 in the vertical direction.

[0021] The reaction vessel 20 may be equipped with a pH meter, a pressure gauge, a thermometer, and a hygrometer (all not shown in the figure).

[0022] One end of the wastewater discharge channel 23 is connected to the reaction vessel 20. The other end of the wastewater discharge channel 23 is connected to the wastewater storage section 60, which will be described later. The wastewater discharge channel 23 discharges the mixed liquid M inside the reaction vessel 20 to the outside as wastewater. The wastewater discharge channel 23 may be equipped with a pump, a flow meter, a pH meter, a pressure gauge, and a thermometer (all not shown). When the pump is driven, the wastewater is discharged through the wastewater discharge channel 23 to the wastewater storage section 60. The flow meter measures the flow rate of the wastewater passing through the wastewater discharge channel 23. The pump is driven and controlled so that the flow rate measured by the flow meter reaches a set amount.

[0023] Examples of pumps include peristaltic pumps, piston pumps, vacuum pumps, screw pumps, gear pumps, and eccentric screw pumps. A pump head may be provided with the pump.

[0024] The flow rate of the waste liquid is set to a value that does not change the mass (or volume) of the mixed liquid M in the reaction vessel 20. More specifically, the flow rate of the waste liquid is set according to the amount of reaction liquid L supplied or the amount of powder P supplied. By discharging the powder P and reaction liquid L supplied to the reaction vessel 20 to the outside of the reaction vessel 20 through the waste liquid discharge channel 23, the mass (or volume) inside the reaction vessel 20 can be kept constant, and the mixed liquid M inside the reaction vessel 20 can be controlled not to overflow. More specifically, the flow rate of the waste liquid is set according to the combined amount of the flow rate of the reaction liquid L and the supply amount of powder P. In practice, the mass of the reaction vessel 20 is measured with a mass scale, and the flow rate of the waste liquid is set so that the measured mass remains constant.

[0025] The wastewater discharge channel 23 may be equipped with a filter to remove dehydrogenated powder P from the wastewater. The filter may be one that removes hydrogenated powder P from the wastewater but does not remove dehydrogenated powder P from the wastewater.

[0026] The average residence time of powder P in the reaction vessel 20 is set to the time required for the reaction between powder P and reaction liquid L. By setting the average residence time, it is possible to dehydrogenate a portion of the total amount of powder P supplied to the reaction vessel 20, preferably 80 mol% or more, more preferably 90 mol% or more, and even more preferably 95 mol% or more of the powder P. Alternatively, the content ω(%) of hydrogenated powder P represented by the following formula (1) in the wastewater discharged from the wastewater discharge channel 23 is preferably 20 mol% or less, more preferably 10 mol% or less, and even more preferably 5 mol% or less. ω = {[moles of hydrogenated powder P]} / {[moles of dehydrogenated powder P + moles of hydrogenated powder P]} ...Equation (1) Furthermore, by setting an average residence time, the concentration in the reaction vessel 20 (the concentration of dehydrogenated powder P in the mixed liquid M, or the concentration of hydrogenated powder P in the mixed liquid M) can be kept constant, thereby increasing the reaction efficiency in the reaction vessel 20.

[0027] The average residence time τ (in s) is calculated using the following equation (3), which is the first-order reaction equation for a continuous-tank reactor (CSTR), as shown in equation (2). <First-order reaction equation> (1-r)X=X / (1+kτ) …Equation (2) however, r: Dehydrogenation rate = 1-ω X: Inflow concentration (M) k: reaction rate coefficient (1 / s) That is the case. <Average residence time> τ=r / {(1-r)k} …Equation (3)

[0028] The average residence time τ can be set based on the desired amount of generated gas (i.e., the desired dehydrogenation rate r) and the reaction rate coefficient k. The reaction rate coefficient k depends on the type of reaction vessel, the type of powder P, the type of reaction solution L, the type of additive, the temperature of the mixture M, the pH of the mixture M, the flow rate of the mixture M, the stirring speed, etc., and can be determined experimentally. Furthermore, the inflow and outflow rates Q (m³) of the reaction vessel can be determined. 3 The reaction vessel volume V(m³) is calculated as ( / s).3 It can be calculated from the average residence time τ using the following equation (4). Q=V / τ …Equation (4) From the viewpoint of reducing the content ω of hydrogenated powder P in the waste liquid represented by formula (1) (i.e., increasing the dehydrogenation rate r), the dehydrogenation rate r is preferably 80% or more, more preferably 90% or more, and even more preferably 95% or more. Therefore, from formula (3), the average residence time τ is preferably satisfied by the following formula (5). 4 / k≦τ≦99 / k …Equation (5)

[0029] Specifically, when the reaction rate coefficient k is 0.001 ≤ k ≤ 0.1, it is preferable that 0.67 min ≤ τ ≤ 1650 min. When the reaction rate coefficient k = 0.001, 67 min ≤ τ ≤ 1650 min When the reaction rate coefficient k = 0.01, 6.7 min ≤ τ ≤ 165 min When the reaction rate coefficient k = 0.1, 0.67 min ≤ τ ≤ 16.5 min It is more preferable to set it to this.

[0030] The reaction vessel 20 is provided with a generated gas discharge channel 22. The generated gas discharge channel 22 discharges the generated gas inside the reaction vessel 20 to the outside. One end of the generated gas discharge channel 22 is connected to the reaction vessel 20. The other end of the generated gas discharge channel 22 may be connected to a gas utilization device 70, which will be described later. The other end of the generated gas discharge channel 22 may be connected to a generated gas storage unit, a generated gas purification device, a gas separation membrane device, or a gas compressor, which will be described later. A pump and a flow meter (neither of which are shown) may be provided in the generated gas discharge channel 22. When the pump is driven, the generated gas generated in the reaction vessel 20 passes through the generated gas discharge channel 22. The flow meter measures the flow rate of the generated gas passing through the generated gas discharge channel 22. The pump may be driven and controlled so that the flow rate of the flow meter reaches a set amount.

[0031] Examples of pumps include peristaltic pumps, piston pumps, vacuum pumps, screw pumps, gear pumps, and eccentric screw pumps. A pump head may be provided with the pump.

[0032] The flow rate of the generated gas is set to a value that does not change the pressure inside the reaction vessel 20. More specifically, the flow rate of the generated gas is set according to the amount of generated gas, the amount of pressurized gas supplied, the amount of powder P supplied, or the pressure inside the reaction vessel 20. By discharging the pressurized gas supplied to the reaction vessel 20 and the generated gas to the outside of the reaction vessel 20 through the generated gas discharge channel 22, the pressure inside the reaction vessel 20 can be kept constant and controlled so as not to exceed the pressure-bearing level of the reaction vessel 20.

[0033] The generated gas discharge passage 22 may be equipped with a filter to remove impurities from the generated gas (for example, dehydrogenated powder P, hydrogenated powder P, water, certain types of gas, etc.).

[0034] The reaction vessel 20 is preferably heated by at least one type of heat selected from the group consisting of waste heat from a heat utilization plant, electromagnetic waves, a heat pump, and a waste heat recovery boiler. The reaction vessel 20 is preferably heated to 30°C to 200°C, more preferably to 50°C to 180°C, and even more preferably to 70°C to 160°C. By heating the reaction vessel 20, the mixed liquid M inside the reaction vessel 20 is also heated to the above temperatures. By heating the mixed solution M, the reaction between powder P and reaction solution L proceeds more easily, resulting in a higher purity generated gas. Furthermore, the dehydrogenated powder P can be recovered as oxoacid. Oxoacid is in a form that is easily recyclable, as will be described later. For example, if powder P is sodium borohydride, it can be dehydrogenated by reaction with reaction solution L and recovered as borax. Borax can also be heated and recovered as anhydrous borax.

[0035] From the viewpoint of excellent durability and pressure resistance, the material of the reaction vessel is preferably metal (including stainless steel, special stainless steel, aluminum alloy, brass, and alloys such as high-carbon steel) or polymer composite material.

[0036] <Powder supply mechanism> The powder supply mechanism 30 continuously supplies a set amount of powder P to the reaction vessel 20 through the powder supply passage 31.

[0037] The powder supply mechanism 30 includes a feeder 32 connected to a powder supply path 31, a first container 33 connected to the feeder 32, and a second container 34 connected to the first container 33. The second container 34 stores the powder P and supplies the powder P to the first container 33. The first container 33 supplies the powder P to the feeder 32, and the powder P is then sent from the feeder 32 to the powder supply path 31. The second container 34 is detachable from the first container 33. The second container 34 is, for example, a cartridge for storing powder P, and the cartridge is replaceable. By removing the second container 34, which has been supplied with powder P and become empty, from the first container 33, and connecting a new second container 34 for storing powder P to the first container 33, powder P can be continuously supplied from the second container 34 to the first container 33. Specifically, the second container 34 supplies powder P to the first container 33 when the amount of powder P contained in the first container 33 decreases and falls below a predetermined threshold, so as not to deplete the powder P in the first container 33. Therefore, the gas generator 10 can generate gas continuously for a long time. Furthermore, powder P can be supplied to the first container 33 without coming into contact with outside air that may contain water vapor.

[0038] The powder supply mechanism 30 may include a hopper (not shown) between the first container 33 and the feeder 32. The hopper may be cylindrical in shape, for example. The powder P moves in the order of the first container 33, the second container 34, the hopper, the feeder 32, and the powder supply path 31, and is supplied to the reaction vessel 20.

[0039] The feeder 32 is driven and controlled to continuously supply a set amount of powder P to the powder supply passage 31. The powder supply passage 31 is connected to the feeder 32 at a position offset from the center to the edge. A stirrer or vibration generator (not shown) for crushing rat holes that occur due to prolonged use may be introduced inside the first container 33 or hopper. To improve the supply of powder P, the diameter may be narrowed from the first container 33 or hopper towards the feeder 32, or the inner wall of the first container 33 or hopper may be given a sliding surface.

[0040] As an example, as shown in Figure 2, the feeder 32 is divided into a first chamber 35a and a second chamber 35b. The first chamber 35a is larger in size than the second chamber 35b. The first chamber 35a is located directly below the first container 33. Therefore, powder P falls into the first chamber 35a from the first container 33 or hopper. The second chamber 35b is located next to the powder supply passage 31. Therefore, the inlet 31a of the powder supply passage 31 is visible into the second chamber 35b. The shape of the inlet 31a may be circular, elliptical, or a polygon such as a regular octagon.

[0041] A first rotating plate 36 is installed in the first chamber 35a. The first rotating plate 36 is a gear composed of a disc-shaped main body 36a and a plurality of protrusions 36b. The protrusions 36b are parts that protrude radially at equal intervals from the outer circumference of the main body 36a. The first rotating plate 36 is rotated counterclockwise at a set rotational speed. During this rotation, the first rotating plate 36 uses the protrusions 36b to transport the powder P toward the second chamber 35b.

[0042] A second rotating plate 37 is installed in the second chamber 35b. The second rotating plate 37 has a smaller diameter than the first rotating plate 36. Like the first rotating plate 36, the second rotating plate 37 is a gear composed of a disc-shaped main body 37a and a plurality of protrusions 37b that project radially at equal intervals from the outer circumference of the main body 37a. The inlet 31a is formed at an eccentric end position from the rotation center of the second rotating plate 37. The protrusions 37b of the second rotating plate 37 mesh with the protrusions 36b of the first rotating plate 36 at the boundary between the first chamber 35a and the second chamber 35b. As a result, the second rotating plate 37 rotates clockwise in response to the counterclockwise rotation of the first rotating plate 36. During this rotation, the second rotating plate 37 uses its protrusions 37b to transport the powder P toward the inlet 31a. In other words, the second rotating plate 37 supplies the powder P to the powder supply passage 31 by scraping it off with the protrusion 37b within the second chamber 35b. In short, the feeder 32 is a circle feeder (also called a table feeder).

[0043] While a circle feeder is given as an example of feeder 32, it is not limited to this. A screw feeder (also called an auger feeder) that continuously supplies a set amount of powder P to the powder supply path 31 by rotating a helical screw with a motor may also be used. Alternatively, feeder 32 may be a dispenser, screw conveyor, extruder, apron conveyor, pneumatic conveyor, roller conveyor, belt conveyor, pelletizer, compounder, weight feeder, acoustic and ultrasonic vibration conveyor, rotary conveyor, electromagnetic conveyor, or vertical conveyor, etc. Feeder 32 can move powder P by any combination of mechanisms selected from gravity, acoustic vibration, ultrasonic vibration, pulsed inertial force, acoustic radiation force, electromagnetic force, vacuum force, weight, apron, belt, roller, rotation, or vertical movement.

[0044] Powder P may be supplied in a predetermined amount. The amount of powder P to be supplied is predetermined based on the type of powder P to be supplied, the type of reaction solution L, and the desired amount of generated gas, etc.

[0045] Flow function is an index that represents the fluidity of a powder; a higher value indicates lower fluidity. Powders with a flow function of 1 or higher do not flow at all. In contrast, powders with a flow function of 0.1 or lower flow very easily. The flow function of powder P is preferably 0.5 or lower, more preferably 0.25 or lower, and even more preferably 0.1 or lower.

[0046] The powder P may be in the form of powder, granules, pellets, or crystals. A powder is an aggregate of multiple fine solid particles. The particle size of the powder P may be between 1 μm and 10,000 μm. The powder P may also be a molded product formed by crushing and granulation or the like to achieve the above particle size of the powder. In this disclosure, the particle size is measured as the volume-average particle size (D50) using a laser diffraction scattering particle size distribution analyzer.

[0047] The metal hydride powder preferably contains at least one selected from the group consisting of lithium hydride, beryllium hydride, sodium hydride, lithium sodium hydride, sodium borohydride, magnesium hydride, aluminum hydride, silicon hydride, potassium hydride, calcium hydride, rubidium hydride, strontium hydride, and barium hydride, and the volumetric hydrogen density (kg-H2 / m³) represents the amount of hydrogen stored in the volume of the powder. 3 From the viewpoint of size, it is more preferable that it be at least one selected from the group consisting of sodium borohydride and magnesium hydride. Metal hydrides may be included individually or in combination of two or more types.

[0048] <Pressurized gas supply mechanism> The pressurized gas supply mechanism 40 supplies pressurized gas to the powder supply passage 31.

[0049] The pressurized gas supply mechanism 40 includes a compressor for generating pressurized gas, a dehumidifier for dehumidifying the pressurized gas, and a pressurized gas storage section for storing the dehumidified pressurized gas (all not shown). While the mixed liquid M is being prepared, the pressurized gas supply mechanism 40 continuously supplies the pressurized gas stored in the pressurized gas storage section to the feeder 32 of the powder supply mechanism 30 through the pressurized gas supply passage 41, thereby supplying pressurized gas to the powder supply passage 31.

[0050] From a safety standpoint, an inert gas is preferred as the pressurized gas, while from the viewpoint of utilizing the generated gas for purposes such as power generation, a flammable gas is preferred as the pressurized gas. Examples of inert gases include carbon dioxide, nitrogen, argon, helium, neon, and air. Flammable gases are gases that burn in air or oxygen, and examples include hydrogen, methane, ethane, propane, butane, acetylene, natural gas, and city gas.

[0051] The pressurized gas is used to apply pressure to the powder P and push it into the reaction vessel 20. Preferably, the pressurized gas has a pressure of 0.1 MPa to 0.2 MPa at 100°C, 0.2 MPa to 0.3 MPa at 120°C, or 0.4 MPa to 0.5 MPa at 140°C.

[0052] A flow straightening member (not shown) may be provided at the connection between the pressurized gas supply passage 41 and the powder supply mechanism 30. The flow straightening member is, for example, a plate-shaped member having slits. The slits may be formed in an annular shape along a circular shape, for example. The flow straightening member makes it possible to suppress the adhesion of powder P to the inner wall surface of the powder supply passage 31 by pressurized gas flowing along the inner wall surface of the powder supply passage 31.

[0053] As the pressurized gas passes through the flow straightening member, the pressurized gas is straightened to flow along the inner wall surface of the powder supply passage 31. The pressurized gas flowing along the inner wall surface of the powder supply passage 31 makes it possible to suppress the adhesion of powder P to the inner wall surface.

[0054] To create a flow of pressurized gas along the inner wall surface of the powder supply passage 31, one might simply consider increasing the flow velocity of the pressurized gas. However, increasing the flow velocity of the pressurized gas causes the powder P to diffuse in a mist-like manner, adhering to the top and inner walls of the reaction vessel 20 and preventing mixing with the reaction liquid L, making it difficult to prepare a mixed liquid M of the set concentration. By creating a flow of pressurized gas along the inner wall surface of the powder supply passage 31 without increasing the flow velocity of the pressurized gas, the powder P becomes less likely to diffuse in a mist-like manner.

[0055] <Reaction liquid storage section> The gas generator 10 further comprises a reaction liquid storage section 50 for storing the reaction liquid L, and a reaction liquid supply passage 51 connected to the reaction liquid storage section 50 for supplying the reaction liquid L to the reaction vessel 20. One end of the reaction liquid supply passage 51 is connected to the reaction liquid storage section 50. The other end of the reaction liquid supply passage 51 is connected to the reaction vessel 20. A pump and a flow meter (both not shown) may be provided in the reaction liquid supply passage 51. When the pump is driven, the reaction liquid L in the reaction liquid storage section 50 is supplied to the reaction vessel 20 through the reaction liquid supply passage 51. The flow meter measures the flow rate of the reaction liquid L passing through the reaction liquid supply passage 51. The pump is driven and controlled so that the flow rate measured by the flow meter reaches a set amount.

[0056] Examples of pumps include peristaltic pumps, piston pumps, vacuum pumps, screw pumps, gear pumps, and eccentric screw pumps. A pump head may be provided with the pump.

[0057] The flow rate of reaction solution L is set to a value such that the mass (or volume) of the mixed liquid M in the reaction vessel 20 does not change. More specifically, the flow rate of reaction solution L is set according to the flow rate of waste liquid or the supply amount of powder P. More specifically, the flow rate of reaction solution L is set according to the amount obtained by subtracting the amount of powder P supplied from the flow rate of waste liquid. In practice, the mass of the reaction vessel 20 is measured with a mass scale, and the flow rate of reaction solution L is set so that the measured mass remains constant.

[0058] Furthermore, in order to adjust the pH of the mixture M, the outflow rate of the reaction vessel 20 may be temporarily increased for a certain period of time, and the inflow rate may be increased to the same amount. This allows the pH to be returned to the neutral side and the reactivity to be restored, for example, if the pH of the mixture M becomes biased towards the basic side and the reactivity deteriorates.

[0059] The reaction liquid L supplied through the reaction liquid supply channel 51 flows down the inner wall surface of the reaction vessel 20. By flowing down the inner wall surface of the reaction vessel 20, the reaction liquid L can be supplied to the reaction vessel 20 while protecting the inner wall surface of the reaction vessel 20. The gas generated by the powder P and the reaction liquid L may cause the reaction vessel 20 to become brittle. In particular, if the generated gas is hydrogen gas and the material of the reaction vessel 20 is metal, the metal will become hydrogen-embrittle due to the hydrogen gas. Therefore, by allowing the reaction liquid L to flow down the inner wall surface of the reaction vessel 20, hydrogen embrittlement of the reaction vessel 20 can be suppressed.

[0060] As a method for allowing the reaction liquid L to flow down the inner wall surface of the reaction vessel 20, for example, the reaction vessel 20 may have a plurality of circular holes in the gas phase section (e.g., the top surface), and the reaction liquid L may be supplied from the plurality of circular holes. The reaction liquid L may be supplied from one reaction liquid supply channel through a plurality of circular holes, or the reaction liquid L may be supplied from multiple reaction liquid supply channels through a plurality of circular holes. Alternatively, a flow straightening member (not shown) may be provided at the connection between the gas phase portion of the reaction vessel 20 and the reaction liquid supply passage 51, and the reaction liquid L may flow down the inner wall surface of the reaction vessel 20 by straightening the flow of the flow straightening member. The flow straightening member may be, for example, a plate-shaped member having a slit. The slit may be formed in an annular shape along a circular shape, for example.

[0061] The reaction liquid storage section 50 may supply the reaction liquid L to the reaction vessel continuously or discontinuously through the reaction liquid supply passage 51. From the viewpoint of easily protecting the inner wall surface of the reaction vessel 20 with the reaction liquid L at all times during the reaction, it is preferable that the reaction liquid L be supplied continuously.

[0062] The reaction solution L can be, for example, water (e.g., pure water, distilled water, deionized water, and tap water), boric acid solution, citric acid solution, or acetic acid solution. The reaction solution L is preferably pH 6 to pH 9, more preferably pH 6 to pH 8, and even more preferably pH 6 to pH 7. By setting the pH to these values, the powder P can be reacted sufficiently.

[0063] The reaction liquid storage section 50 or the reaction liquid supply passage 51 may be heated by at least one type of heat selected from the group consisting of factory waste heat, electromagnetic waves, a heat pump, and a waste heat recovery boiler. By heating the reaction liquid storage section 50 or the reaction liquid supply passage 51, the reaction liquid L is also heated. The temperature of the reaction liquid L is preferably 60°C to 100°C, and more preferably 80°C to 100°C. Furthermore, if the reaction solution L is water, the reaction vessel 20 may be pressurized and heated to preferably 100-140°C, more preferably 120-140°C. If the reaction solution L is boric acid solution, the temperature of the reaction solution L is preferably 40-80°C, and more preferably 60-80°C.

[0064] <Other mechanisms or parts> The gas generator 10 may include other mechanisms or parts besides the reaction vessel 20, powder supply mechanism 30, pressurized gas supply mechanism 40, and reaction liquid storage section 50. Examples of other mechanisms or parts include a waste liquid storage section 60 and an additive supply mechanism.

[0065] (Waste liquid storage section) The waste liquid storage unit 60 stores the mixed liquid M discharged from the reaction vessel 20 as waste liquid. Figure 1 shows an example in which the gas generator 10 is directly connected to the waste liquid storage unit 60, but the system is not limited to this.

[0066] The waste liquid storage section 60 may be equipped with a waste liquid purification filter, heat dissipation equipment, and dewatering equipment, etc. The wastewater purification filter removes dehydrogenated powder P from the wastewater. The filter may also remove hydrogenated powder P from the wastewater but not dehydrogenated powder P.

[0067] For example, if the powder P is sodium borohydride, the dehydrogenated powder P contained in the waste liquid, such as sodium metaborate or borax, may be recycled back into sodium borohydride and supplied again to the powder supply mechanism 30 as powder P.

[0068] (Additive supply mechanism) The additive supply mechanism supplies further additives to the powder P, reaction solution L, or mixture M. Examples of additives include defoamers and oxidizing agents (e.g., citric acid).

[0069] <Application> The gas generated by the gas generator of this disclosure may be used, for example, as an additive for bright annealing, an additive for hydrogenated desulfurization, an additive during resin production, for diluting raw material gases, for atmospheres, as a curing agent for solidifying raw material oils and fats, for glass manufacturing, power generation equipment, methanation equipment, hydrogen bacteria culture equipment, or synthesis equipment for synthesizing organic substances from carbon oxide and hydrogen.

[0070] ≪Gas Utilization System≫ The gas utilization system of the present disclosure comprises a gas generator of the present disclosure and a gas utilization device to which the generated gas obtained from the gas generator is supplied, wherein the pressurized gas in the gas generator includes at least one selected from the group consisting of hydrogen gas and methane gas.

[0071] The pressurized gas in the gas generator preferably contains at least one selected from the group consisting of hydrogen gas and methane gas, and more preferably at least one selected from the group consisting of hydrogen gas and methane gas. According to a gas generator 10, which is one embodiment of a gas generator, not only the generated gas produced by the reaction between powder P and reaction liquid L, but also pressurized gas is discharged from the generated gas discharge passage 22 provided by the gas generator 10. When the gas discharged from the generated gas discharge passage 22 is used, for example, by combustion, it is preferable that the content of combustible gas in the gas discharged from the generated gas discharge passage 22 is high in order to increase combustion efficiency. Examples of combustible gases include hydrogen gas, methane gas, ethane gas, propane gas, butane gas, acetylene gas, natural gas, and city gas. Therefore, it is more preferable that the pressurized gas in the gas generator be at least one selected from the group consisting of hydrogen gas and methane gas, and that the generated gas produced by the gas generator is hydrogen gas.

[0072] <Gas Generator> The gas generator in the gas utilization system of this disclosure is as described above, and one embodiment is the gas generator 10 described above.

[0073] <Gas utilization equipment> The gas utilization device in the gas utilization system of this disclosure is preferably a power generation device, a methanation device, a hydrogen bacteria culture device, or a synthesis device for synthesizing organic matter from carbon oxide and hydrogen.

[0074] Examples of power generation devices include gas turbines and gas engines. These power generation devices can produce electricity using hydrogen gas or methane gas as fuel. A methanation device can produce methane gas using carbon dioxide and hydrogen gas as raw materials. By using a hydrogen bacteria culture device, hydrogen bacteria, which use hydrogen as an energy source, can be cultured by supplying them with hydrogen gas. Organic substances can be obtained using hydrogen gas as a raw material through a synthesis apparatus that synthesizes organic substances from carbon dioxide and hydrogen.

[0075] In Figure 1, an example is shown where the gas generator 10 is directly connected to the gas utilization device 70, but this is not the only example.

[0076] The gas utilization device in the gas utilization system of this disclosure may be a device that utilizes only the generated gas produced in the gas generator of this disclosure, or it may be a device that co-combusts the generated gas produced in the gas generator of this disclosure with other gases. In the case of co-combustion, it is preferable that both the generated gas produced in the gas generator of this disclosure and the other gases are combustible gases.

[0077] <Other devices> The gas utilization system of this disclosure may include other devices besides a gas generator and a gas utilization device. Other devices may be installed between the gas generator and the gas utilization device, and examples include a generated gas storage unit, a generated gas purification device, a gas separation membrane device, and a gas compressor. The generated gas storage unit stores the generated gas produced by the gas generator. The generated gas purification device purifies the generated gas. A gas separation membrane system separates the generated gas according to its type. A gas compressor compresses the generated gas.

[0078] As described above, the gas generator of this disclosure is a gas generator that continuously generates gas from a powder of metal hydride, and the gas utilization system of this disclosure utilizes the above gas generator. [Explanation of symbols]

[0079] 10 Gas generator 20 Reaction vessel 21 Agitator 22. Gas discharge channel 23 Wastewater discharge channel 30 Powder supply mechanism 31 Powder supply path 31a Entrance 32 Feeder 33 1st container 34 Second container 35a Room 1 35b Room 2 36. First Rotation Plate 36a Main body 36b Protrusion 37. Second Rotating Plate 37a Main body 37b Protrusion 40 Pressurized gas supply mechanism 41 Pressurized gas supply channel 50 Reaction solution storage section 51 Reaction liquid supply channel 60 Wastewater storage section 70 Gas utilization equipment L reaction solution M mixture P powder

Claims

1. A reaction vessel equipped with a stirrer, which mixes metal hydride powder and reaction solution to obtain generated gas, A powder supply mechanism is connected to a powder supply passage and supplies the powder to the reaction vessel through the powder supply passage, A pressurized gas supply mechanism that continuously supplies the powder to the reaction vessel by continuously supplying pressurized gas to the powder supply passage, A gas generator equipped with the following features.

2. The powder supply mechanism comprises a feeder connected to the powder supply path, a first container connected to the feeder, and a second container connected to the first container. The gas generator according to claim 1, wherein the second container stores the powder and supplies the powder to the first container, and the first container supplies the powder to the feeder, thereby sending the powder from the feeder to the powder supply path.

3. The gas generator according to claim 1 or claim 2, wherein the generated gas is hydrogen gas.

4. The gas generator according to claim 1 or claim 2, wherein the metal hydride includes at least one selected from the group consisting of lithium hydride, beryllium hydride, sodium hydride, lithium sodium hydride, sodium borohydride, magnesium hydride, aluminum hydride, silicon hydride, potassium hydride, calcium hydride, rubidium hydride, strontium hydride, and barium hydride.

5. The system further comprises a reaction liquid storage section for storing the reaction liquid, and a reaction liquid supply passage connected to the reaction liquid storage section for supplying the reaction liquid to the reaction vessel, The gas generator according to claim 1 or claim 2, wherein the reaction liquid supplied through the reaction liquid supply channel flows down along the inner wall surface of the reaction vessel.

6. The gas generator according to claim 1 or claim 2, wherein the average residence time of the powder in the reaction vessel is set to the time required for the reaction between the powder and the reaction liquid.

7. The gas generator according to claim 6, wherein the average residence time τ satisfies 4 / k ≤ τ ≤ 99 / k.

8. The gas generator according to claim 1 or 2, wherein the agitator stirs the mixture of the powder and the reaction liquid from the bottom to the top of the reaction vessel, and at least one selected from the group consisting of the hydrogenated powder and the dehydrogenated powder is discharged to the outside of the reaction vessel through a waste liquid discharge passage.

9. The gas generator according to claim 1 or claim 2, which is installed in a heat utilization plant and in which the reaction vessel is heated by waste heat from the plant.

10. The gas generator according to claim 1 or claim 2, wherein the reaction vessel is heated by electromagnetic waves.

11. A gas generator according to claim 1 or claim 2, The system comprises a gas utilization device to which the generated gas obtained from the gas generator is supplied, A gas utilization system wherein the pressurized gas in the gas generator includes at least one selected from the group consisting of hydrogen gas and methane gas.

12. The gas utilization system according to claim 11, wherein the gas utilization device is a power generation device, a methanation device, a hydrogen bacteria culture device, or a synthesis device for synthesizing organic matter from carbon oxide and hydrogen.

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