KR101507769B1 - Reduction Method of Oxide and Apparatus for Reducing Oxide Using the Same - Google Patents

Abstract

The present invention relates to an oxide reduction method comprising an oxidation reduction method comprising an irradiation step of irradiating a metal oxide trapped with oxygen to a deep ultraviolet ray to separate the oxygen trapped in the metal oxide, a basic structure formed into a plate or block shape, A metal oxide layer coated on the surface of the basic structure and oxygen-trapped therein, and a deep-UV photoirradiation module for irradiating the metal oxide layer with a deep-UV beam.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oxide reduction method and an oxide reduction method using the oxide reduction method.

The present invention relates to an oxide reduction method and an oxide reduction apparatus using the same.

Since the nuclear accident in Japan, research on the development of new and renewable energy has been actively conducted. Among them, there is a strong interest in research for using hydrogen as an energy source, especially for research on hydrogen production from water. However, in order to generate hydrogen from water, it is necessary to break the bond between the hydrogen molecule and the oxygen molecule. Since the connection is strong, a high reaction energy is required to generate hydrogen, and it takes a lot of cost.

Recently, many researches have been made on a method of producing hydrogen by decomposing water by a thermochemical method using a metal oxide. A method of producing hydrogen using a metal oxide is a method in which water or water vapor is contacted with a metal oxide to cause decomposition reaction of water to generate hydrogen. In the method using a metal oxide, it is necessary to increase the contact area between the metal oxide surface and water, and conventionally, a void is formed inside the metal oxide structure to increase the contact area. However, there is a limit in forming voids inside the metal oxide structure, and it is difficult to make a void structure connected from one side to the other side.

In addition, since the metal oxide generates hydrogen while collecting the oxygen itself in contact with water, the oxygen trapping ability disappears after a lapse of a predetermined time. Therefore, the metal oxide must be reduced through a reduction reaction. However, there is a method using heating or solar energy, but the efficiency is low and the structure for heating or solar energy irradiation is complicated. Particularly, the reduction reaction of the oxide requires a temperature of 1000 ° C or more, complicating the structure for heating, adiabatic cooling and cooling.

The present invention provides an oxide reduction method capable of reducing a metal oxide by irradiating a deep ultraviolet ray and an oxide reduction apparatus using the same.

The oxide reduction method according to the present invention is characterized by comprising an irradiating step of irradiating a deep ultraviolet ray to a metal oxide trapped with oxygen to separate the oxygen trapped in the metal oxide. Further, the oxide reduction method according to the present invention may further include a heating step of heating the metal oxide, and the heating step may be performed so as to proceed with the irradiation step or before or after the irradiation step. At this time, the metal oxide may be formed of a metal oxide including at least one material selected from Ce, Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge.

The deep ultraviolet light may be irradiated by a deep ultraviolet light emitting diode, a UV lamp, or a UV laser.

In the heating step, the heating temperature may be set between a temperature higher than room temperature and a temperature lower than 1000 ° C.

In addition, the oxide reduction apparatus of the present invention comprises a base structure formed in a plate or block shape, a metal oxide layer formed by coating a surface of the base structure with a metal oxide and oxygen trapped thereon, And a deep ultraviolet light irradiation module for irradiating the ultraviolet light.

In addition, the basic structure may be formed of a three-dimensional network structure having a plurality of pores connected to each other and penetrating from the inside to the outside, and may include any metal selected from nickel, aluminum, stainless steel, and copper .

The nanostructure may include at least one material selected from the group consisting of Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge. And may be formed of a metal oxide.

The metal oxide may be formed of a metal oxide including at least one material selected from Ce, Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge.

The deep-ultraviolet light irradiation module may include any one of a Deep Ultraviolet light emitting diode, a UV lamp, and a UV laser.

The oxide reduction device may further include a heating module positioned at a lower portion or an upper portion of the basic structure and heating the metal oxide layer.

In addition, the oxide reduction apparatus removes oxygen trapped in the metal oxide layer in a hydrogen generation apparatus for generating hydrogen by hydrogen generation reaction while bringing steam into contact with the metal oxide layer to trap oxygen in the metal oxide layer .

The oxide reduction method and the oxide reduction apparatus using the oxide reduction method according to the present invention have the effect of reducing the metal oxide at a room temperature or a lower temperature than the conventional one by irradiating the metal oxide layer with the deep ultraviolet light.

The oxide reduction method and the oxide reduction apparatus using the oxide reduction method according to the present invention reduce the metal oxide at a room temperature or a temperature lower than the conventional temperature, so that the oxide can be reduced in a simple structure and at a low cost.

1 is a schematic diagram of an oxide reduction apparatus according to an embodiment of the present invention.
FIG. 2 is a partial SEM photograph of a nanostructure coated with Fe ₃ O ₄ particles after SnO ₂ nanowires are formed on the surface of the internal structure of the basic structure, which is applied to the oxide reduction apparatus of FIG.
3 is a graph showing the amount of hydrogen production before and after metal oxide reduction in the oxide reduction apparatus of FIG.

Hereinafter, an oxide reduction method and an oxide reduction apparatus using the oxide reduction method of the present invention will be described in detail with reference to embodiments and accompanying drawings.

First, an oxide reduction method according to an embodiment of the present invention will be described.

The oxide reduction method according to the present invention comprises an irradiation step of irradiating a metal oxide having undergone a hydrogen generation reaction to a deep ultraviolet ray. In addition, the oxide reduction method may further include a heating step of heating the metal oxide.

The oxide reduction method is applied to a method of separating and reducing oxygen from oxygen-trapped metal oxide. In the oxide reduction method, in particular, oxygen trapped in the metal oxide is removed by a reduction reaction by the formula (2) in the hydrogen production reaction process according to the following formula 1) for generating hydrogen by supplying water vapor to the metal oxide, The present invention can be applied to an oxide reduction method that allows a hydrogen production reaction to proceed.

M _x O _{y -1} + H ₂ O - M _x O _y + H ₂ - ????? (1)

M _x O _y + E (Deep Ultraviolet light) - M _x O _{y -1} + 1 / 2O ₂ - (2)

The irradiating step is a step of irradiating the metal oxide trapped with oxygen with a deep ultraviolet ray. The deep ultraviolet light refers to light having a peak emission wavelength of 265 nm to 295 nm. The deep ultraviolet light may be irradiated from a deep ultraviolet light emitting diode, a UV lamp or a UV laser. The deep-ultraviolet light is irradiated to the trapped metal oxide layer to supply energy, and an instantaneous reduction reaction for separating oxygen trapped in the metal oxide proceeds as shown in Equation (2).

The metal oxide is formed of a metal oxide containing at least one material selected from Ce, Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge, and Fe ₃ O ₄ , Fe ₂ O _{3, CeO 2, Ce 2 O} 3 Or a mixture thereof. The metal oxide layer traps oxygen from the supplied water vapor, and the oxygen is separated by the deep ultraviolet light.

The heating step is a step of heating the oxygen-trapped metal oxide. The heating step may be conducted before or after the irradiation step, or with the irradiation step.

The metal oxide separates the trapped oxygen more efficiently and quickly when heat energy is applied by heating. The heating step heats the metal oxide to a heating temperature higher than normal temperature. When the metal oxide is heated to a temperature higher than room temperature, the reduction reaction is promoted, and the oxygen is more efficiently separated. The heating temperature is set between a temperature higher than room temperature and a temperature lower than or equal to 1000 ° C, and preferably set at a temperature lower than or equal to 100 ° C. The metal oxide layer requires a temperature higher than 1000 占 폚 in order to remove oxygen by pure heating. However, since the heating step is performed as an auxiliary means for the irradiation step, the heating can be performed at a relatively low temperature. If the heating temperature is too high, energy is unnecessarily consumed, and the basic structure supporting the metal oxide may be damaged.

The heating step preferably proceeds to heat the metal oxide as a whole. Therefore, the heating step is performed so that the heat is entirely or directly applied to the basic structure on which the metal oxide is coated. For example, when the basic structure is formed of an electrical conductor such as a metal, electricity is applied to heat the metal oxide by heat generation of the basic structure. Further, when the basic structure is formed of an electric nonconductor such as plastic or ceramic, a separate heating element which physically contacts the electric insulator is formed so that heat generated by the heating element is conducted through the basic structure to heat the metal oxide layer do. Further, a separate heating element or light source is positioned on the upper surface adjacent to the surface of the metal oxide layer, and heat generated from the heating element or the light source is radiated to heat the metal oxide.

Next, an oxide reduction apparatus to which the oxide reduction method of the present invention is applied will be described.

1 is a schematic diagram of an oxide reduction apparatus according to an embodiment of the present invention. FIG. 2 is a partial SEM photograph of a nanostructure coated with Fe ₃ O ₄ particles after SnO ₂ nanowires are formed on the surface of the internal structure of the basic structure, which is applied to the oxide reduction apparatus of FIG.

Referring to FIG. 1, an oxide reduction apparatus according to an embodiment of the present invention includes a basic structure 110, a metal oxide layer 120, and a deep-diffuse-light irradiation module 130. In addition, the oxide reduction apparatus may further include a heating module 140.

The oxide reduction apparatus removes oxygen by irradiating a deep ultraviolet ray to the metal oxide layer 120 in which oxygen is trapped. The oxide reduction apparatus can be applied to various apparatuses required to remove oxygen trapped in the metal oxide layer 120. For example, the oxide reduction apparatus can be applied to a hydrogen generation apparatus that generates hydrogen using water vapor. The hydrogen generating apparatus is a device for generating hydrogen by bringing water vapor into contact with the metal oxide layer 120 to generate hydrogen. At this time, the hydrogen generating apparatus traps oxygen of water vapor in the metal oxide layer and generates hydrogen scavenger. The hydrogen generating apparatus may further include a structure such as a steam supplying means and a hydrogen collecting means necessary for generating hydrogen, and a detailed description thereof will be omitted. When the trap concentration of oxygen increases by a certain amount or more, the metal oxide layer 120 can no longer trap oxygen. The hydrogen generating apparatus irradiates the metal oxide layer 120 with a deep ultraviolet ray to remove oxygen from the metal oxide layer 120 and to allow the hydrogen production reaction to proceed.

The basic structure 110 may be formed of an electrically nonconductive material such as an electrical conductor such as a metal, a plastic or a ceramic. The existing structure may preferably be formed of a metal such as nickel, aluminum, stainless steel or copper, which is excellent in corrosion resistance and thermal conductivity. The basic structure 110 may be formed in a plate or block shape. 2, the basic structure 110 may have a three-dimensional network structure or a three-dimensional network structure in which a plurality of pores 110a are formed to penetrate from the inside to the outside and are connected to each other . When the basic structure 110 is formed in a three-dimensional structure, the surface area per unit volume is increased and the area of the metal oxide layer 120 coated on the surface is increased. In the basic structure 110, water vapor passing through the internal pores causes a hydrogen generation reaction with the metal oxide layer 120 to generate hydrogen.

In addition, the basic structure 110 may be formed by coating the nanowires 115 on the surface. Herein, the nanowire includes nanoscale materials such as nanoparticles. Referring to FIG. 2, the nanowire may be formed to lie in the longitudinal direction on the surface of the base structure 110, or protrude outward from the surface. The nanowires increase the surface area of the base structure 110 and increase the area over which the metal oxide layer 120 is applied. The nanowire may be formed of a metal or a metal oxide. The nanowire may be formed of a metal oxide including at least one material selected from Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge. For example, the nanowire may be formed of an oxide such as Mn ₃ O ₄ , MgO, CoO, SnO _{2 ,} ZnO, ZnS, Al ₂ O ₃ , SiO _{2 ,} In ₂ O ₃ , GeO ₂ . In addition, the nanowire may include Fe ₃ O ₄ , Fe ₂ O ₃ , CeO ₂ , Ce ₂ O _3, or a mixture thereof.

The metal oxide layer 120 is formed by coating a metal oxide on the surface of the base structure 110. The metal oxide layer 120 may be coated on the surface of the nanowire coated on the surface of the base structure 110. The metal oxide layer 120 may be formed of a continuous coating layer having a predetermined thickness, or may be formed of a discontinuous point-like layer. The metal oxide layer 120 is formed of a metal oxide containing at least one material selected from the group consisting of Ce, Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge, Fe ₃ O ₄ , Fe ₂ O ₃ , CeO ₂ , Ce ₂ O ₃ Or a mixture thereof.

The metal oxide layer 120 separates hydrogen by trapping oxygen in the supplied steam. The metal oxide layer 120 has a reduced ability to trap oxygen when the concentration of trapped oxygen is increased. Accordingly, the metal oxide layer 120 recovers the ability to generate hydrogen again when the trapped oxygen is separated.

The metal oxide layer 120 may be formed by the following process. First, a metal salt solution containing a metal component of the metal oxide is coated on the surface of the base structure 110 by a spin coating or a dipping coating method. Next, the metal salt coated on the basic structure 110 is reduced to form the metal oxide layer 120. Referring to FIG. 2, the metal oxide layer 120 is uniformly coated on the skeletal structure surface of the basic structure 110 as a whole.

The deep-ultraviolet light irradiation module 130 may include any one selected from a Deep Ultraviolet light emitting diode, a UV lamp, and a UV laser. The deep-diffuse-light irradiation module 130 irradiates the metal oxide layer 120 with a deep-ultraviolet light including light having a peak emission wavelength of 265 nm to 295 nm. The deep ultraviolet light irradiation module 130 may irradiate ultraviolet light including deep ultraviolet light. That is, the deep-diffuse-light irradiation module can irradiate the light including the deep-ultraviolet-light and the ultraviolet-light of another wavelength. The deep ultraviolet light irradiation module 130 includes at least one deep ultraviolet LED 130a, and one or more deep ultraviolet LEDs are arranged in a plane. At this time, the deep-ultraviolet light irradiation module 130 is formed to have an area corresponding to the area of the metal oxide layer 120 or more. The deep-UV double-light irradiation module 130 is installed to irradiate deep UV light to the metal oxide layer 120 by a predetermined distance from the top of the metal oxide layer 120. The deep-ultraviolet light irradiation module 130 irradiates deep-ultraviolet light onto the oxygen-trapped metal oxide layer 120 and removes trapped oxygen.

The heating module 140 includes a heating wire and is positioned below or above the basic structure 110. The heating module 140 heats the metal oxide layer 120 and the basic structure 110 by electric power supplied by a separate electric supply means (not shown). The heating module 140 may be formed to simultaneously heat the metal oxide layer 120 and the basic structure 110 or directly heat the metal oxide layer 120. At this time, the heating module 140 may be formed to heat the basic structure 110 and conduct heat to the metal oxide layer 120. The heating module 140 may be disposed on the metal oxide layer 120 to directly heat the metal oxide layer 120. The heating module 140 is formed to heat the metal oxide layer 120 to a temperature higher than room temperature and to be heated to 1000 ° C or lower. The heating module 140 preferably heats the metal oxide layer 120 to 100 ° C or less. The heating module 140 heats the metal oxide layer 120 when oxygen is removed from the metal oxide layer 120 so that oxygen can be removed more efficiently. In addition, the heating module 140 heats the metal oxide layer 120 when hydrogen is generated in the metal oxide layer 120 so that hydrogen can be generated more efficiently.

Next, measurement results using the hydrogen generating apparatus to which the oxide reduction apparatus according to an embodiment of the present invention is applied will be described.

3 is a graph showing the amount of hydrogen production before and after metal oxide reduction in the oxide reduction apparatus of FIG.

3 shows a basic structure 110 having a diameter of 25.4 mm (1 inch) and a thickness of 9 mm and having a skeletal structure coated with a SnO ₂ nanowire and a metal oxide layer 120 of Fe ₃ O ₄ , Are stacked one on top of another to produce a hydrogen production device. According to the measurement results, it can be seen that the amount of hydrogen production increases as the temperature of the metal oxide layer 120 increases in the first hydrogen production reaction. In addition, it can be seen that the amount of hydrogen generated in the basic structure 110 and the metal oxide layer 120 drastically decreases when the hydrogen generation reaction proceeds at about 700 ° C for about 300 minutes. This is because the amount of oxygen trapped in the metal oxide layer 120 is increased, and the place where oxygen is trapped is reduced. In addition, it is estimated that the amount of hydrogen generated in the initial one time of the metal oxide layer 120 is about 400 mL.

Next, the metal oxide layer 120 is reduced by the deep-UV beam irradiated by the deep-UV light irradiation module 130 after the initial one-time hydrogen generation reaction is completed, and then the hydrogen production amount is measured again. At this time, the metal oxide layer 120 was reduced by being heated to 100 ° C. by the heating module 140. According to the measurement results, the metal oxide layer 120 shows a hydrogen production reaction at a relatively low temperature, but the hydrogen production rate per minute is similar to the first one. However, the time of the hydrogen-producing part of the metal oxide layer 120 is relatively short, but it can be increased by increasing the reduction reaction time.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. It is.

110: Basic structure
120: metal oxide layer
130: Deep UV light irradiation module
140: Heating module

Claims (12)

Irradiating a metal oxide having oxygen trapped therein with a deep ultraviolet ray to separate the oxygen trapped in the metal oxide,
Further comprising a heating step of heating the metal oxide,
Wherein the heating step proceeds with the irradiation step or before or after the irradiation step. delete The method according to claim 1,
Wherein the metal oxide is formed of a metal oxide containing at least one material selected from Ce, Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge. The method according to claim 1,
Wherein the deep ultraviolet light is irradiated by one of a deep ultraviolet light emitting diode, a UV lamp, and a UV laser. The method according to claim 1,
Wherein the heating step is set at a heating temperature between a temperature higher than room temperature and a temperature lower than 1000 ° C. A base structure formed in a plate or block shape,
A metal oxide layer formed by coating a surface of the basic structure with oxygen,
And a deep-UV photoirradiation module for irradiating the metal oxide layer with a deep ultraviolet ray. The method according to claim 6,
The basic structure is formed in a three-dimensional network structure having a plurality of pores connected to each other and penetrating from the inside to the outside,
Nickel, aluminum, stainless steel, and copper. ≪ RTI ID = 0.0 > 21. < / RTI > The method according to claim 6,
The basic structure is formed by coating a nanowire on a surface,
Wherein the nanowire is formed of a metal oxide including at least one material selected from Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge. The method according to claim 6,
Wherein the metal oxide is formed of a metal oxide containing at least one material selected from Ce, Fe, Si, Mn, Mg, Co, Zn, Sn, In, Ti and Ge. The method according to claim 6,
Wherein the deep-diffuse-light irradiation module comprises any one of a deep ultraviolet light emitting diode, a UV lamp, and a UV laser. The method according to claim 6,
Further comprising a heating module located below or above the basic structure and heating the metal oxide layer. The method according to claim 6,
Wherein the oxide reduction device is formed to remove oxygen trapped in the metal oxide layer in a hydrogen generation device for generating hydrogen by a hydrogen generation reaction while contacting water vapor with the metal oxide layer to trap oxygen in the metal oxide layer Wherein the oxide reduction device is an oxide reduction device.

Images