JP2010249345A - Device for acquiring alkali metal or alkaline earth metal from alkali metal chloride or alkaline earth metal chloride - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for acquiring alkali metal and alkaline earth metal by using solar heat as an energy source. <P>SOLUTION: The device is installed with a parabola type condenser 1 opened with a hole in a bottom top part, a sub-mirror 2 installed in a focal point neighborhood of the condenser 1, and a heat resistant crucible 5 in a course passing solar light reflected by the sub-mirror 2 through the hole 4 of the bottom top part of the condenser 1 and in a rear side of the condenser 1. Solar light is reflected by a concave of the parabola type condenser 1, it is condensed at the focal point, it is guided to the rear side of the condenser 1 through the hole opened in the bottom top part of the condenser 1, the heat resistant crucible 5 holding a melting reception object is installed in a place in the course, and the melting reception object is melted by solar heat. Alternately, a reflecting mirror is provided in the course of solar light, and reflected light of the reflecting mirror is irradiated on the heat resistant crucible to melt the melting reception object. The molten object is electrolyzed as it is to acquire alkali metal and alkaline earth metal. The melting reception object is a chloride or its mixture of alkali metal and alkaline earth metal. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for obtaining an alkali metal or alkaline earth metal from an alkali metal chloride or alkaline earth metal chloride.

  Alkali metals or alkaline earth metals are very dangerous substances. When exposed to air, it may oxidize rapidly and cause an explosion, and when exposed to water, it reacts rapidly and burns while generating hydrogen gas.

  In recent years, there is concern about the deterioration of the global environment, and a method for purifying the environment is being sought. As part of this, the use of clean energy sources has been studied. In general, energy sources include electric power energy, wind energy, wave energy, geothermal energy, and thermal energy obtained by burning fossil fuels such as oil and coal.

  As for power energy, currently, thermal power generation is the mainstay, and power energy generated by hydroelectric power generation, nuclear power generation, wind power generation, geothermal power generation, solar power generation, etc. is supplied. Thermal power generation is often discussed as a cause of air pollution by exhaust gas because it burns oil and coal. In addition, exhaust gas causes air pollution in automobiles that run on engines by burning gasoline or the like. For these reasons, wind energy and solar energy are attracting attention as clean energy that does not pollute the global environment.

  On the other hand, there is an attempt to use hydrogen gas as an energy source. That is, it is used as an energy source for fuel cells. When used as a fuel cell, only water is discharged and there is no concern about environmental pollution. There is also a movement to use hydrogen gas as fuel for internal combustion engines.

JP 2006-194230 A JP 2006-258085 A

  In view of the above, the present inventor has made use of alkali metal, alkaline earth, and the like in order to utilize a reaction in which hydrogen gas is generated by contacting an alkali metal such as metallic sodium and an alkaline earth metal such as metallic magnesium with water. While research on obtaining a similar metal at a low cost was made, it was found that it could be obtained efficiently by using solar heat, and the present invention was completed.

  That is, the feature of the present invention is that an alkali metal chloride or an alkaline earth metal chloride is put in a heat-resistant crucible, melted by solar heat condensed by a parabolic solar collector, and then electrolyzed. To obtain an alkali metal, an alkaline earth metal or a mixture thereof.

  The present invention provides an apparatus for obtaining an alkali metal or alkaline earth metal by melting an alkali metal chloride or alkaline earth metal chloride using solar heat and electrolyzing the melt. Alkali metals and alkaline earth metals can generate hydrogen gas by reacting with water. The generated hydrogen gas can be used as a new energy source and as a raw material for chemical synthesis. Even in countries where oil resources are scarce or none, it is possible to easily secure an energy source and contribute greatly to the industry.

1 is a schematic view of an apparatus showing an embodiment of the present invention. Schematic which shows the state of the crucible suspended. The schematic of the apparatus which shows the embodiment which put the heat-resistant crucible on the ground.

  The present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing an outline of an apparatus for obtaining an object using a parabolic solar concentrator having a concave reflecting surface. Sunlight collected by a parabolic concentrator directed toward the sun by a sun tracking device (not shown) is reflected by the concave surface, and light is collected near the focal point. When a heat-resistant crucible containing a material to be melted is placed in the vicinity of the focal point, it is heated by the collected solar heat, and the material to be melted in the crucible is melted. Although it can be implemented in this manner, it is preferable to place the crucible on the back side of the condenser.

  Sunlight incident on the parabolic concentrator 1 (also referred to as a primary mirror) is reflected by the concave reflecting surface and converges to the concave focal point. A secondary mirror 2 is installed in the vicinity of the focal point. The secondary mirror is fixed by a support arm 3 extending from the outer edge of the parabolic concentrator. As the secondary mirror, either a concave mirror or a convex mirror can be used, but a concave mirror is preferably used. Sunlight reflected from the collector can be reflected by the secondary mirror 2 and reflected toward the bottom top of the collector. If a hole is made in the bottom top, sunlight can be guided to the back side of the collector through the hole. A hole 4 is formed in the bottom top of the collector, and the reflected light is guided to the back side of the collector. A heat-resistant crucible 5 in which a material to be melted is placed in a place corresponding to the path of sunlight is provided on the back side of the collector, and the material to be melted is heated by solar heat. The heat-resistant crucible is fixed by a detachable suspension device. Since the subsequent electrolysis is performed while the molten salt mixture is still in the heat-resistant crucible, the heat-resistant crucible is preferably installed at a location close to the ground surface.

  The parabolic concentrator senses the direction of sunlight and is set to point in the direction of the strongest incident light. Therefore, when the direction of sunlight cannot be sensed sensitively, such as when it is cloudy, the tracking device is switched off. It is also turned off after sunset.

  The material of the heat-resistant crucible containing the material to be melted used in the present invention is preferably made of ceramic. A heat-resistant temperature of 1000 ° C. or higher is sufficient. For example, those made of silicon carbide are preferred. Moreover, since the electrolysis operation is performed with the material to be melted in the crucible, it is preferable that the crucible be kept vertical. One such embodiment is shown in FIG. The crucible is hung by a hook 7 at the tip of the suspension bar 6 on the back side of the parabolic concentrator, where it hits the path of sunlight. In order to keep the crucible vertical, a method can be employed in which the crucible is kept vertical by attaching a plate-like ring 8 around the upper part of the crucible and attaching it to the hook 7 with support rods 9 extending from the plate-like ring to both sides. The support bar and the hook are not fixed, and it is preferable that the crucible can be rotated back and forth around the support bar.

  In another embodiment, a heat resistant crucible can be installed on the ground, as shown in FIG. The reflection mirror 10 is installed in a place where the sunlight reflected from the secondary mirror hits the course of sunlight on the back side of the collector, and the heat-resistant crucible placed on the ground can be irradiated and heated. Here, the reflecting mirror acts to reflect and irradiate sunlight irradiated from the secondary mirror toward the heat-resistant crucible. As the reflecting mirror, a concave mirror, a convex mirror or a plane mirror can be used, but a plane mirror can be preferably used. In this method, the molten material in the heat-resistant crucible can be electrolyzed on the ground and the product can be taken out, so there is less danger compared to the method in which the heat-resistant crucible is suspended, but the course of sunlight that changes every moment. It is necessary to always irradiate the heat-resistant crucible with the reflected light. For this reason, the installation angle of the plane mirror is adjusted so that the incident angle of sunlight and the reflection angle to the heat-resistant crucible are the same.

  The crucible and the support frame may be a set of units, or the support frame may be left as it is and only the crucible may be replaced. In the case of a set of units, several sets of units may be prepared and used for replacement.

  The material to be melted used in the present invention is an alkali metal chloride or an alkaline earth metal chloride, and a mixture thereof is used. Although salts other than chlorides can be used, chlorides are preferably used from the viewpoint of treatment of acid gas by-produced in the subsequent electrolysis step. In melting the material to be melted, it is preferable not to put a large amount of the material to be melted in the crucible from the beginning, but to add a small amount first and then add the material to be melted after melting starts, so that the entire amount is melted.

  Any alkali metal or alkaline earth metal may be used as long as it can easily generate hydrogen gas by reacting with water, and sodium and magnesium are preferable from the viewpoint of easy availability. Alkaline earth metals are less likely to react with water as the atomic weight increases, and magnesium is preferred because hydrogen gas is not generated unless it is a dilute acid. However, even if other alkali metals or alkaline earth metals are contained, there is no problem for the purpose of generating hydrogen gas.

  Sodium or magnesium chloride can be obtained by evaporating seawater as a chloride or a mixture of chlorides containing these metal chlorides as the main component. Moreover, rock salt can also be used as a raw material.

  Depending on the composition, these materials to be melted will not melt unless the temperature is 600 ° C. or higher or 800 ° C. Concentrated solar heat varies depending on the season, time zone, and weather, but in midsummer and fine weather, the crucible is heated to about 800 ° C. in about 10 minutes after heating, and the contents melt. Under such circumstances, the present invention is an invention that is efficiently implemented in low latitude subtropical regions, tropical regions, and desert regions where little rain falls.

  The electrolysis of the molten mixture can be performed by a normal method, but it must be performed while maintaining a temperature at which the melt does not solidify. Once the melt has solidified, it cannot be electrolyzed even when energized. As an electrode, a carbon rod can be used as an anode, and an iron rod can be used as a cathode. The energization value can be 4 to 6 V and 3 to 5 A. Since chlorine gas is generated at the anode, it is necessary to use a material resistant to chlorine as the electrode.

  As the electric power used for the electrolysis, the electric power obtained by the method of generating electricity by solar heat proposed by the present inventors in Japanese Patent Application Nos. 2007-139788 and 2007-156284 can be used. According to this method, the melting and electrolysis of the material to be melted can all be covered by solar thermal energy. Of course, power obtained by other methods can also be used.

  Metals electrolyzed and deposited on the cathode are stored at the bottom of the crucible. Slag accumulates in the surface layer of the crucible. To remove the metal accumulated at the bottom of the crucible, cool the temperature of the crucible to about 200 ° C, and tilt the crucible into the oil to obtain the metal without touching the air. Can do.

  A device in which a concave reflecting mirror was installed in the vicinity of the focal point of a parabolic concentrator having a diameter of 1 m was used. A hole having a diameter of 10 cm is formed at the bottom top of the condenser so that the reflected light from the concave reflecting mirror can pass through. Two suspension bars were attached to the back of the concentrator, and a heat-resistant crucible supported by a support bar was hung on the hook at the tip. The size of the heat-resistant crucible was 5 cm in diameter and 7 cm in depth. The crucible was placed so that the reflected light hits the top surface from the side of the crucible. The crucible was supported by a support rod and maintained the vertical direction.

  A carbon rod as an anode and an iron rod as a cathode were set in a crucible, and about 30 g of sodium chloride was further added to irradiate reflected light. About 9 minutes after irradiation, the crucible reached 850 ° C. or higher, and the salt began to melt. Chlorine gas was generated from the anode that was electrolyzed by applying a direct current of 6 V and 4 A to the electrode after melting, and silver gray metallic sodium was deposited near the cathode. The crucible was removed from the hook and cooled to about 200 ° C., and then the contents were put into a container filled with kerosene. About 11 g of metallic sodium was obtained.

  Instead of salt, a mixture of about 1: 1 of salt and magnesium chloride was put in a crucible, and the same operation as in Example 1 was performed. The crucible reached around 850 ° C. about 9 minutes after irradiation, and the mixture began to melt. Thereafter, the same operation as in Example 1 was performed. As a result, chlorine gas was generated from the anode, and about 10 g of a mixture of silver-gray metallic sodium and metallic magnesium was obtained near the cathode.

  According to the present invention, alkali metal chloride or alkaline earth metal chloride is melted using solar heat, and the melt is electrolyzed to obtain alkali metal or alkaline earth metal. Alkali metal and alkaline earth metal can generate hydrogen gas by reacting with water, and the generated hydrogen gas can be used as a new energy source and as a raw material for chemical synthesis. Even in countries with little or no resources, it is easy to secure an energy source and make a significant contribution to the industry.

1 …… Parabolic concentrator 2 …… Secondary mirror 3 …… Secondary mirror support arm 4 ...... Hole 5 …… Heat-resistant crucible 6 …… Suspension rod 7 …… Hook 8 …… Wheel 9 …… Support rod 10 …… Reflector

Claims (5)

  A parabolic concentrator with a hole at the bottom, a secondary mirror installed near the focal point of the collector, and the sunlight reflected by the secondary mirror is a path through the hole at the bottom of the collector. An apparatus for obtaining an alkali metal, an alkaline earth metal or a mixture thereof, wherein a heat-resistant crucible is installed on the back side of the condenser.   A parabolic concentrator with a hole at the bottom, a secondary mirror installed near the focal point of the collector, and the sunlight reflected by the secondary mirror is a path through the hole at the bottom of the collector. An apparatus for obtaining an alkali metal, an alkaline earth metal or a mixture thereof, wherein a reflector for reflecting sunlight toward a heat-resistant crucible is installed on the back side of the condenser.   3. An apparatus for obtaining an alkali metal, an alkaline earth metal or a mixture thereof according to claim 1, wherein an electrode for electrolysis is incorporated in a heat-resistant crucible.   The apparatus for obtaining an alkali metal, an alkaline earth metal or a mixture thereof according to claim 1 or 2, wherein the secondary mirror is either a concave mirror or a convex mirror.   3. The apparatus for obtaining an alkali metal, an alkaline earth metal or a mixture thereof according to claim 2, wherein the reflecting mirror according to claim 2 is any one of a concave mirror, a convex mirror and a plane mirror.