JP2016038186A - Chemical loop combustion apparatus, power generation apparatus and chemical loop combustion method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chemical loop combustion apparatus in which supply of carbon-containing substance from a fuel reactor to an air reactor is suppressed.SOLUTION: A chemical loop combustion device 10a comprises an air reactor 5 for oxidizing a solid-state reductant agent containing metal with oxygen in air to generate a solid-state oxidizer containing metal and oxygen; a fuel reactor 6 for oxidizing carbon-containing fuel with oxidizer to generate carbon dioxide-containing gas and reductant agent; a carbon separator 7 which is supplied with fuel-derived carbon-containing substance and reductant agent from the fuel reactor 6, oxidizes carbon-containing substance to generate carbon dioxide-containing gas and separates the gas from the reductant agent; and a fourth line 4 for supplying oxidant generated by the air reactor 5 to the carbon separator 7. In the carbon separator 7, carbon-containing substance is oxidized with oxidant supplied through the fourth line 4 to generate gas.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a chemical loop combustion apparatus, a power generation apparatus, and a chemical loop combustion method.

  In order to suppress global warming, it is necessary to recover the carbon dioxide produced with the combustion of fossil fuels. The exhaust gas generated by the combustion of fossil fuel contains not only carbon dioxide but also oxygen, nitrogen or nitrogen oxides derived from air. Therefore, in order to collect carbon dioxide, a process for separating carbon dioxide from exhaust gas is required. However, a great deal of energy is consumed in the separation process. For example, in the carbon dioxide adsorption / desorption process, a large amount of energy is required to control the temperature of the adsorbent or the pressure of the atmosphere surrounding the adsorbent.

  In recent years, a method called chemical loop combustion (chemical combustion) has attracted attention as a method for easily recovering carbon dioxide in exhaust gas (see Patent Document 1 below). A chemical loop combustion reactor (chemical loop combustion device) is mainly composed of a combination of an air reactor and a fuel reactor. In the chemical loop combustion method, a reducing agent containing metal (so-called oxygen carrier) is oxidized with oxygen in the air in an air reactor to generate an oxidizing agent containing metal and oxygen. In the air reactor, since there is no fuel, carbon dioxide and nitrogen oxides are hardly generated. The oxidant produced in the air reactor is supplied to the fuel reactor. In the fuel reactor, a fuel containing carbon is oxidized with an oxidant to generate a gas containing carbon dioxide and a reducing agent. The reducing agent produced in the fuel reactor is returned to the air reactor, oxidized again, and reused as the oxidizing agent. As described above, in the chemical loop combustion method, the oxygen carrier circulating between the air reactor and the fuel reactor mediates oxygen from the air to the fuel. That is, air does not react directly with fuel. Therefore, in the chemical loop combustion method, the exhaust gas generated by the oxidation (combustion) of the fuel does not contain nitrogen derived from air, and carbon dioxide can be easily recovered.

Special table 2012-529614 gazette

  In the chemical loop combustion method, when excess fuel is supplied to the fuel reactor or the temperature in the fuel reactor is low, a part of the fuel does not burn. Carbon-containing materials derived from unburned or incompletely burned fuel are supplied from the fuel reactor to the air reactor together with the reducing agent. As a result, the carbon-containing material is oxidized in the air reactor to generate carbon dioxide, and the exhaust gas of the air reactor contains not only nitrogen and oxygen derived from air but also carbon dioxide. In order to separate and recover carbon dioxide from the exhaust gas, extra cost and energy are required. Therefore, it is necessary to prevent the carbon-containing material from being supplied from the fuel reactor to the air reactor.

  Patent Document 1 discloses a technique for physically separating and recovering a carbon-containing substance using a carbon separator (carbon stripper). In this technique, a carbon separator is installed between the fuel reactor and the air reactor. A carbon-containing substance (unburned fuel particles) and a reducing agent (metal oxide particles) discharged from the fuel reactor are supplied to the carbon separator. A fluidizing gas is supplied into the carbon separator, and a moving bed is formed from the carbon-containing material and the reducing agent in the carbon separator. Then, the carbon-containing material is physically separated by classification based on the difference in density and particle size of the carbon-containing material and the reducing agent. The separated carbon-containing material is discharged from the carbon separator by the fluidizing gas and recovered to the fuel reactor. The reducing agent separated from the carbon-containing material is supplied from the carbon separator to the air reactor.

  However, in the carbon separator described in Patent Document 1, it is difficult to separate a carbon-containing substance having a density and particle size comparable to that of the reducing agent from the reducing agent. In addition, carbon-containing materials having a high density and a large particle size are not easily discharged from the carbon separator. In addition, it is difficult to separate the carbon-containing material attached to the reducing agent from the reducing agent. Further, the temperature of the carbon-containing material is lowered in the process in which the carbon-containing material is supplied from the fuel reactor to the carbon separator. Accordingly, when the carbon-containing material is recovered from the carbon separator to the fuel reactor, the temperature in the fuel reactor is lowered, and fuel combustion can be inhibited. As a result, carbon-containing material may again be supplied from the fuel reactor to the carbon separator.

  Patent Document 1 discloses that water vapor is supplied as a fluidizing gas into a carbon separator. If the temperature in the carbon separator is sufficiently high, the carbon-containing material can be chemically separated from the reducing agent by reforming (oxidation) of the carbon-containing material with water vapor. However, in the process in which the carbon-containing material and the reducing agent are supplied from the fuel reactor to the carbon separator, the temperature of the carbon-containing material and the reducing agent decreases. Therefore, the temperature in the carbon separator is not high enough to promote the reforming of the carbon-containing material. Moreover, since the reducing agent supplied to the carbon separator has already been reduced in the fuel reactor, the oxygen content in the reducing agent is small. Therefore, the oxidizing power of the reducing agent supplied to the carbon separator is weak, and the reducing agent hardly promotes the reforming of the carbon-containing material.

  For the above reasons, in the conventional chemical loop combustion apparatus, a part of the carbon-containing material is not separated from the reducing agent in the carbon separator and is supplied to the air reactor.

  The present invention has been made in view of the above circumstances, and a chemical loop combustion apparatus capable of suppressing the supply of a carbon-containing substance from a fuel reactor to an air reactor, and power generation including the chemical loop combustion apparatus An object is to provide an apparatus and a chemical loop combustion method.

  A chemical loop combustion apparatus according to one aspect of the present invention includes an air reactor that oxidizes a solid reducing agent containing metal with oxygen in the air to generate a solid oxidizing agent containing metal and oxygen, and carbon. A fuel reactor containing a gas containing carbon dioxide and a gas containing carbon dioxide and a reducing agent, a carbon-containing substance derived from the fuel, and a reducing agent are supplied from the fuel reactor. A carbon separator that oxidizes the carbon-containing material to generate a gas containing carbon dioxide and separates the gas from the reducing agent; a first line that supplies the oxidizing agent generated in the air reactor to the fuel reactor; A second line for supplying the carbon-containing material and the reducing agent from the fuel reactor to the carbon separator, a third line for supplying the reducing agent from the carbon separator to the air reactor, and an oxidant generated in the air reactor. A fourth line for supplying the carbon separator; Comprising, in a carbon separator, the oxidizing agent supplied through the fourth line, to oxidize the carbonaceous material to produce a gas.

  The chemical loop combustion method according to one aspect of the present invention includes a step of oxidizing a solid reducing agent containing a metal with oxygen in the air in an air reactor to generate a solid oxidizing agent containing the metal and oxygen. Supplying an oxidizing agent from the air reactor to the fuel reactor, and oxidizing a fuel containing carbon with the oxidizing agent in the fuel reactor to generate a gas containing carbon dioxide and a reducing agent. A step of supplying a carbon-containing substance derived from fuel and a reducing agent from the fuel reactor to the carbon separator, a step of supplying an oxidizing agent from the air reactor to the carbon separator, and a carbon separator. A step of oxidizing a carbon-containing substance by an oxidant supplied from an air reactor to generate a gas containing carbon dioxide and separating the gas from the reducing agent; and the reducing agent from the carbon separator to the air reactor. A process of supplying to .

  Since the oxidant supplied from the air reactor to the carbon separator does not pass through the fuel reactor, it retains strong oxidizing power. In addition, since the oxidation of the reducing agent in the air reactor is an exothermic reaction, the temperature of the oxidizing agent supplied from the air reactor to the carbon separator depends on the carbon-containing material and the reduction supplied from the fuel reactor to the carbon separator. Higher than the drug. Thus, by supplying a high-temperature oxidizing agent having a strong oxidizing power to the carbon separator, the oxidation (gasification) of the carbon-containing substance in the carbon separator is promoted, and the gas is separated from the reducing agent. As a result, the carbon-containing substance is suppressed from being supplied from the fuel reactor to the air reactor, and the production of carbon dioxide in the air reactor is suppressed.

  The chemical loop combustion apparatus according to one aspect of the present invention is based on the measurement means for measuring the carbon dioxide content in the gas discharged from the air reactor, and the carbon dioxide content measured by the measurement means. And a controller for controlling the amount of oxidant fed from the air reactor through the fourth line to the carbon separator.

  As the content of carbon dioxide in the gas discharged from the air reactor increases, by increasing the amount of oxidant supplied to the carbon separator, the oxidation of the carbon-containing material in the carbon separator is further promoted, It becomes difficult for the carbon-containing material to be supplied from the carbon separator to the air reactor.

  A chemical loop combustion apparatus according to an aspect of the present invention is provided in the middle of a second line or a third line, and at least a part of a reducing agent is partially oxidized with water vapor to generate at least hydrogen. May further be provided.

  According to the chemical loop combustion apparatus provided with a hydrogen generator, hydrogen can be produced.

  A chemical loop combustion apparatus according to an aspect of the present invention is provided in the middle of a first line, separates an oxidant and a gas supplied from an air reactor, and separates the separated oxidant into a fuel reactor and a carbon separator. You may further provide the powder separator (cyclone) supplied to at least one of the vessels.

  The gas supplied from the air reactor to the powder separator contains at least nitrogen derived from air. By separating the gas from the oxidant using the powder separator, nitrogen is suppressed from being supplied to the fuel reactor or the carbon separator together with the oxidant. As a result, mixing of carbon dioxide and nitrogen in the fuel reactor or carbon separator is suppressed.

  A power generation device according to one aspect of the present invention includes the chemical loop combustion device described above and a turbine generator driven by a gas supplied from the chemical loop combustion device.

  According to the power generator according to one aspect of the present invention, carbon dioxide generated with power generation is easily recovered.

  ADVANTAGE OF THE INVENTION According to this invention, the chemical loop combustion apparatus which can suppress that a carbon containing material is supplied to an air reactor from a fuel reactor, an electric power generating apparatus provided with the said chemical loop combustion apparatus, and a chemical loop combustion method are provided. Is done.

FIG. 1 is a schematic diagram of a chemical loop combustion apparatus and a power generation apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram of a power generation apparatus including a chemical loop combustion apparatus and a power generation apparatus according to a second embodiment of the present invention. FIG. 3 is a schematic diagram of a chemical loop combustion apparatus and a power generation apparatus according to a third embodiment of the present invention. FIG. 4 is a schematic diagram of a chemical loop combustion apparatus and a power generation apparatus according to a fourth embodiment of the present invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals. The present invention is not limited to the following embodiment.

[First embodiment]
(Chemical loop combustion apparatus and chemical loop combustion method)
As shown in FIG. 1, the chemical loop combustion apparatus 10a according to the first embodiment includes an air reactor 5, a first line 1, a first powder separator 8a, a fuel reactor 6, a second line 2, and a carbon separation. A vessel 7, a third line 3, a fourth line 4, a measuring means 9, a control device 11, a valve 12, a second powder separator 8b, a first heat exchanger 14a and a second heat exchanger 14b. The positional relationship of the components of these chemical loop combustion apparatuses 10a may be as shown in FIG. “Line” means a tube that transports a substance. The first line 1 connects the air reactor 5 and the fuel reactor 6. The second line 2 connects the fuel reactor 6 and the carbon separator 7. The third line 3 connects the carbon separator 7 and the air reactor 5.

  The line connecting the upper part of the air reactor 5 and the first powder separator 8 a is a part common to the first line 1 and the fourth line 4. One line branched at the lower part of the first powder separator 8 a is a part of the first line 1 and is connected to the fuel reactor 6. The other line branched at the lower part of the first powder separator 8 a is a part of the fourth line 4 and is connected to the carbon separator 7. Thus, the first powder separator 8 a is provided in the middle of the first line 1 and the fourth line 4.

  The chemical loop combustion method according to the first embodiment is performed using a chemical loop combustion apparatus 10a as described below.

  A solid reducing agent containing metal is supplied into the air reactor 5. Air A is supplied from the lower part of the air reactor 5 into the air reactor 5. In the air reactor 5, a moving bed or a fluidized bed is formed from the reducing agent and air A. That is, the air reactor 5 may be a moving bed reactor or a fluidized bed reactor. In the moving bed or fluidized bed, the reducing agent is oxidized with oxygen in the air A to generate a solid oxidizing agent containing metal and oxygen. Since the oxidation of the reducing agent is an exothermic reaction, the temperature in the air reactor 5 is maintained at a high temperature by the oxidation of the reducing agent. Therefore, the oxidant and gas in the air reactor 5 are heated at a high temperature. The gas in the air reactor 5 contains nitrogen and oxygen derived from the air A. Although the temperature in the air reactor 5 is not specifically limited, For example, it may be 500 degreeC or more and 1200 degrees C or less. In the first embodiment, the oxidant in the air reactor 5 is blown off to the upper part of the air reactor 5 by the air A supplied from the lower part of the air reactor 5 and discharged from the upper part of the air reactor 5 together with the gas. The The air reactor 5 may be a riser that moves the oxygen carrier (reducing agent or oxidant) vertically upward by the upward flow of the air A to give potential energy or kinetic energy to the oxygen carrier. As a result of the oxygen carrier being driven by this energy, the oxygen carrier may circulate in the chemical loop combustion apparatus 10a. Water may be supplied into the air reactor 5 together with the air A to generate water vapor and discharged from the upper part of the air reactor 5.

The reducing agent is represented by, for example, the general formula MO _x . In the general formula, M is a metal, and x is a real number of 0 or more. That is, the reducing agent may be a single metal or a metal oxide. The metal M is not particularly limited, but may be at least one selected from the group consisting of Ni, Fe, Cu, Co, and Mn, for example. A plurality of simple metals may be used as the reducing agent. A plurality of metal oxides may be used as the reducing agent. A composite oxide containing a plurality of metals (for example, a perovskite oxide) may be used as the reducing agent. The reducing agent may include a metal or metal oxide and a carrier on which the metal or metal oxide is supported. The support is not particularly limited, and examples thereof include Al ₂ O ₃ , ZrO ₂ , TiO ₂ , SiO ₂ , MgO, NiAl ₂ O ₄ , CoAl ₂ O ₄ , YSZ (Ytria-Stabilized Zirconia), CuAl ₂ O _4, and AlPO. It may be at least one selected from the group consisting of ₄ . The reducing agent may include a plurality of types of carriers. The particle size of the reducing agent is not particularly limited, and may be, for example, 50 μm or more and 1000 μm or less, or 100 μm or more and 500 μm or less. The oxidizing agent is represented by, for example, a general formula MO _{x + y} . In the general formula, y is a positive real number. The reducing agent and the oxidizing agent may be a powder.

  The oxidant and gas in the air reactor 5 are supplied to the first powder separator 8 a through a line common to the first line 1 and the fourth line 4. The oxidant is separated from the high-temperature gas g3 by the first powder separator 8a. The separated oxidant is supplied to the fuel reactor 6 through the first line 1 extending from the lower part of the first powder separator 8a. The separated oxidizing agent is supplied to the carbon separator 7 through the fourth line 4 extending from the lower part of the first powder separator 8a. The separated high-temperature gas g3 is supplied from the first powder separator 8a to the first heat exchanger 14a.

  The fourth line 4 extending from the lower part of the first powder separator 8a is inclined with respect to the vertical direction. Since the fourth line 4 is inclined, the accumulation of the oxidizing agent in the fourth line 4 and the clogging of the fourth line 4 due to the oxidizing agent are suppressed.

  The oxidant supplied from the first line 1 is dropped into the fuel reactor 6 from the upper part of the fuel reactor 6. The first fluidizing gas G <b> 1 is supplied from the lower part of the fuel reactor 6 into the fuel reactor 6. In the fuel reactor 6, the fuel F containing carbon and the oxidant are fluidized with the first fluidizing gas G1 to form a fluidized bed. The fuel F is oxidized with an oxidant in the fluidized bed to generate a high temperature first gas g1 containing carbon dioxide and a reducing agent.

  The temperature in the fuel reactor 6 depends on the temperature of the high-temperature oxidant supplied from the air reactor 5 and the reaction rate. Although the temperature in the fuel reactor 6 is not specifically limited, For example, it may be 500 degreeC or more and 1200 degrees C or less.

  The first fluidizing gas G1 is a gas other than air. The first fluidizing gas G1 may be at least one selected from the group consisting of water vapor, carbon dioxide, and oxygen, for example. A plurality of first fluidizing gases G1 may be used. When the first fluidizing gas G1 is steam, the steam reforming reaction or the water gas shift reaction proceeds in the fuel reactor 6 and the oxidation of the fuel F is promoted.

  The fuel F may be at least one selected from the group consisting of solid fuel, liquid fuel, and gaseous fuel. The solid fuel is not particularly limited, but may be at least one selected from the group consisting of coal, coke, plastic, and biomass fuel, for example. The liquid fuel is not particularly limited, but may be at least one selected from the group consisting of light oil, heavy oil, kerosene and gasoline, for example. The gaseous fuel is not particularly limited, and may be at least one selected from the group consisting of methane, propane, butane, natural gas, and coal gasification gas, for example. Multiple types of fuels may be used. The fuel F may be particles. The first fluidizing gas G1 may include gaseous fuel. That is, gaseous fuel may be used as the first fluidizing gas G1. In this case, a fluidized bed may be formed from the oxidant and the first fluidized gas G1 in the fuel reactor 6, and the gaseous fuel contained in the first fluidized gas G1 may be oxidized by the oxidant in the fluidized bed.

  The first gas g1 may include, for example, carbon monoxide, hydrogen, or water in addition to carbon dioxide.

  In the fuel reactor 6, the carbon-containing substance derived from the fuel remains. The carbon-containing material may be a solid or liquid derived from fuel. The carbon-containing material can be, for example, a portion of the fuel that has not been oxidized. The carbon-containing material can be, for example, an organic compound produced by incomplete oxidation of the fuel. The carbon-containing material may be an inorganic compound such as coal char, for example. The carbon-containing material may include, for example, hydrogen or a hetero element (eg, oxygen, sulfur, or nitrogen). The carbon-containing material may be a particle. A solid carbon-containing material may adhere to the reducing agent. The liquid carbon-containing material may adhere to the solid carbon-containing material or the reducing agent. The liquid carbon-containing material may be tar, for example. In particular, when a solid fuel is used, a carbon-containing substance derived from the solid fuel tends to remain in the fuel reactor 6.

  The carbon-containing substance and the reducing agent are supplied to the carbon separator 7 from the lower part of the fuel reactor 6 through the second line 2. Further, the first gas g1 separated from the carbon-containing substance and the reducing agent is discharged from the upper part of the fuel reactor 6 and supplied to the second powder separator 8b.

  The oxidant supplied from the air reactor 5 through the fourth line 4 is dropped into the carbon separator 7 from the upper part of the carbon separator 7. The second fluidizing gas G <b> 2 is supplied from the lower part of the carbon separator 7 into the carbon separator 7. In the carbon separator 7, the carbon-containing substance, the oxidizing agent, and the reducing agent are fluidized with the second fluidizing gas G2 to form a fluidized bed. In the fluidized bed, the carbon-containing material is oxidized with an oxidizing agent to generate a second gas g2 containing carbon dioxide and a reducing agent. The second gas g2 is discharged from the upper part of the carbon separator 7, and the second gas g2 is separated from the reducing agent. The second gas g2 discharged from the upper part of the carbon separator 7 is supplied to the second powder separator 8b. The reducing agent remaining in the carbon separator 7 includes a reducing agent derived from the oxidizing agent supplied from the fourth line 4 and a reducing agent supplied from the second line.

  The second fluidizing gas G2 is a gas other than air. The second fluidizing gas G2 may be at least one selected from the group consisting of water vapor, carbon dioxide, and oxygen, for example. A plurality of types of second fluidizing gases G2 may be used. When the second fluidizing gas G2 is steam, the steam reforming reaction and the water gas shift reaction proceed in the carbon separator 7, and the reaction of the carbon-containing substance (gasification by oxidation) is promoted.

  The second gas g2 may include, for example, carbon monoxide, hydrogen, or water in addition to carbon dioxide.

  In the first embodiment, since the carbon-containing material is oxidized (gasified) by a high-temperature oxidizing agent having strong oxidizing power, it is possible to remove the carbon-containing material that is difficult to remove by a conventional physical method from the reducing agent. it can. That is, in the first embodiment, it is possible to remove a carbon-containing material having a density and particle size comparable to those of the reducing agent. In addition, a carbon-containing substance having a high density and a large particle diameter can be removed. Furthermore, the carbon-containing substance adhering to the reducing agent can be removed from the reducing agent. In the first embodiment, it is not necessary to physically separate the carbon-containing material from the reducing agent, and it is not necessary to recover the carbon-containing material from the carbon separator 7 to the fuel reactor 6. In particular, when a solid fuel is used, the carbon-containing material derived from the solid fuel is likely to remain in the fuel reactor 6, but according to the first embodiment, the carbon-containing material derived from the solid fuel is contained in the carbon separator 7. It can be easily removed from the reducing agent.

  In the first embodiment, since the oxidizing agent having a strong oxidizing power and a high temperature is supplied from the air reactor 5 to the carbon separator 7, in the carbon separator 7 as compared with the conventional method of supplying only water vapor to the carbon separator. The reaction (gasification by oxidation) of the carbon-containing substance is easily promoted.

  The reducing agent from which the carbon-containing material has been removed is supplied from the lower part of the carbon separator 7 to the lower part of the air reactor 5. When a part of the oxidizing agent remains in the carbon separator 7 without oxidizing the carbon-containing material, the oxidizing agent is also supplied to the air reactor 5 together with the reducing agent. In the air reactor 5, the reducing agent is again oxidized with oxygen in the air A to regenerate the oxidizing agent. The regenerated oxidant is supplied again to the fuel reactor 6 and the carbon separator 7.

  The measuring means 9 may be installed, for example, in the vicinity of the upper part of the air reactor 5 (in the vicinity of the oxidant and gas outlet in the air reactor 5). The measurement means 9 may be installed in the middle of the 1st line 1 located between the air reactor 5 and the 1st powder separator 8a, for example.

  The measuring means 9 may be a gas sensor, for example. From the measuring means 9, the content of carbon dioxide in the gas discharged together with the oxidant from the upper part of the air reactor 5 is measured. When the carbon-containing substance is supplied from the carbon separator 7 to the air reactor 5, carbon dioxide is detected by the measuring means 9.

  For example, the valve 12 may be installed in the vicinity of a portion where the fourth line 4 is connected to the first powder separator 8a. The valve 12 may be installed in the middle of the fourth line 4, for example. The flow rate of the oxidizing agent in the fourth line 4 is adjusted by opening and closing the valve 12.

  The control device 11 acquires the data of the carbon dioxide content measured by the measuring means 9, opens and closes the valve 12 based on the carbon dioxide content, and passes through the fourth line 4 from the air reactor 5 to the carbon separator. 7 controls the amount of oxidant (for example, the supply rate) supplied to 7. For example, with the increase in the carbon dioxide content measured by the measuring means 9, the control device 11 opens the valve 12 to increase the amount of oxidant supplied to the carbon separator 7. As a result, the oxidation of the carbon-containing material in the carbon separator 7 is further promoted, and the carbon-containing material is hardly supplied from the carbon separator 7 to the air reactor 5.

  The amount of oxidant supplied to the carbon separator 7 may be continuously changed by the control device 11 in accordance with the change in the carbon dioxide content continuously measured by the measuring means 9. When the carbon dioxide content measured by the measuring means 9 exceeds a predetermined allowable value (threshold value), the control device 11 opens the valve 12 to start supplying the oxidizing agent to the carbon separator 7, The amount of oxidant supplied to the separator 7 may be increased. When the carbon dioxide content to be measured falls below a predetermined allowable value, the control device 11 closes the valve 12 to stop the supply of the oxidant to the carbon separator 7 or to the carbon separator 7. The supply amount of the oxidizing agent may be reduced.

  When the amount of oxidant supplied to the carbon separator 7 is increased by the control device 11, the amount of oxidant supplied from the air reactor 5 to the fuel reactor 6 through the first line 1 decreases. When the amount of oxidant supplied to the fuel reactor 6 decreases, a part of the fuel F may not be oxidized, and a carbon-containing substance may be supplied from the fuel reactor 6 to the carbon separator 7. Therefore, the supply amount of the fuel F to the fuel reactor 6 may be controlled by the control device 11. For example, as the amount of oxidant supplied to the carbon separator 7 increases, the supply of the fuel F to the fuel reactor 6 is stopped, or the supply amount of the fuel F to the fuel reactor 6 is decreased. Good. In addition, the supply amount of the oxidant to the fuel reactor 6 may be controlled by the control device 11.

  The chemical loop combustion apparatus 10 a may include an auxiliary heater that heats the carbon separator 7. By heating the inside of the carbon separator 7 with an auxiliary heater, the oxidation of the carbon-containing substance in the carbon separator 7 is promoted. However, in the first embodiment, since the oxidizing agent having a strong oxidizing power and a high temperature is supplied from the air reactor 5 to the carbon separator 7, the carbon-containing material in the carbon separator 7 is oxidized without an auxiliary heater. Can be promoted.

  In the 1st heat exchanger 14a, water is heated with the high temperature gas g3 supplied from the 1st powder separator 8a, and high temperature water vapor | steam is generated. That is, the gas g3 is cooled with water.

  The cooled gas g3 is recovered. Fine solids (for example, ash) remaining in the recovered gas g3 may be removed with a dust collector. The recovered gas g3 contains nitrogen as a main component. The recovered gas g3 may contain oxygen as a subcomponent. High purity nitrogen can be obtained by separating and removing components other than nitrogen from the recovered gas g3. High purity nitrogen is used, for example, in the chemical industry, the electrical machinery industry, or the steel industry.

  In the second powder separator 8b, the solid content mixed in the first gas g1 and the second gas g2 is separated. The separated solid content is discharged from the lower part of the second powder separator 8b. The solid content may include, for example, a reducing agent, an oxidant, or ash produced by oxidation of fuel F.

  The first gas g1 and the second gas g2 separated from the solid content are supplied from the second powder separator 8b to the second heat exchanger 14b. In the second heat exchanger 14b, water is heated with the first gas g1 and the second gas g2 to generate high-temperature water vapor. That is, the first gas g1 and the second gas g2 are cooled with water.

  The cooled first gas g1 and second gas g2 are recovered. The recovered first gas g1 and second gas g2 contain carbon dioxide as a main component. Fine solids (for example, ash) remaining in the first gas g1 and the second gas g2 may be removed with a dust collector. Subsequently, the water contained in the first gas g1 and the second gas g2 may be removed with a dehydrator. By removing the water contained in the first gas g1 and the second gas g2, high-purity carbon dioxide is obtained. High-purity carbon dioxide is used, for example, as a gas for arc welding, a raw material for carbonated beverages, a coolant, a supercritical fluid for industrial processes, or a raw material for chemical products.

(Power generation device)
The power generation apparatus 100a according to the first embodiment includes a chemical loop combustion apparatus 10a and a turbine generator 20. The turbine generator 20 includes a turbine 20a and a generator 20b driven by the turbine 20a. The turbine 20a is a steam turbine. High-temperature steam is supplied from the first heat exchanger 14a and the second heat exchanger 14b to the turbine 20a. Electric power is generated by driving the turbine 20a with steam and driving the generator 20b with the turbine 20a.

[Second Embodiment]
The second embodiment of the present invention is the same as the first embodiment except for the matters described below. According to the second embodiment, similarly to the first embodiment, it is possible to prevent the carbon-containing material from being supplied from the fuel reactor 6 to the air reactor 5.

  As shown in FIG. 2, the power generation apparatus 100 b according to the second embodiment includes a chemical loop combustion apparatus 10 b and a turbine generator 20. In the chemical loop combustion apparatus 10b according to the second embodiment, the fourth line 4 directly connects the upper part of the air reactor 5 and the carbon separator 7 without going through the first powder separator 8a. Therefore, in the second embodiment, not only the oxidizing agent but also a high-temperature gas containing nitrogen and oxygen is supplied from the air reactor 5 to the carbon separator 7 through the fourth line 4. The oxidant and oxygen supplied from the air reactor 5 oxidize the carbon-containing material in the carbon separator 7. Nitrogen supplied from the air reactor 5 does not participate in the oxidation of the carbon-containing material. The second gas g2 discharged from the upper part of the carbon separator 7 contains at least carbon dioxide and nitrogen. Therefore, in the second embodiment, a step of separating carbon dioxide and nitrogen in the second gas g2 from each other may be performed.

[Third embodiment]
The third embodiment of the present invention is the same as the first embodiment except for the matters described below. According to the third embodiment, similarly to the first embodiment, it is possible to prevent the carbon-containing material from being supplied from the fuel reactor 6 to the air reactor 5.

  As shown in FIG. 3, the power generation apparatus 100 c according to the third embodiment includes a chemical loop combustion apparatus 10 c and a turbine generator 20. The chemical loop combustion apparatus 10c according to the third embodiment further includes a hydrogen generator 13, a third powder separator 8c, and a third heat exchanger 14c. The hydrogen generator 13 is provided in the middle of the second line 2. Through the second line 2, the carbon-containing material and the reducing agent are supplied from the fuel reactor 6 to the hydrogen generator 13.

The carbon-containing substance and the oxidant supplied from the air reactor 5 are dropped into the hydrogen generator 13 from the upper part of the hydrogen generator 13. Steam is supplied from the lower part of the hydrogen generator 13 into the hydrogen generator 13. In the hydrogen generator 13, the carbon-containing substance and the reducing agent are fluidized with steam to form a fluidized bed. In the fluidized bed, at least a part of the reducing agent is partially oxidized with water vapor to generate a gas containing hydrogen (hydrogen-containing gas h). That is, the water-containing gas h is generated by reducing water vapor with a reducing agent. A part of the reducing agent may be completely oxidized to produce an oxidizing agent represented by the general formula MO _{x + y} . The reducing agent partially oxidized by steam is represented by, for example, the general formula MO _{x + z} . In the general formula, z is a positive real number smaller than y. In the hydrogen generator 13, a part of the carbon-containing material may be oxidized with water vapor to generate hydrogen and carbon dioxide or carbon monoxide. That is, the hydrogen-containing gas h may contain carbon dioxide or carbon monoxide. The hydrogen-containing gas h may further contain, for example, hydrogen sulfide or water.

  The carbon-containing material, the reducing agent, and the partially oxidized reducing agent remaining in the hydrogen generator 13 are supplied from the lower part of the hydrogen generator 13 to the upper part of the carbon separator 7 through the second line 2. When an oxidant is generated in the hydrogen generator 13, the oxidant is also supplied from the hydrogen generator 13 to the carbon separator 7 through the second line 2. In the third embodiment, at least a part of the reducing agent is partially oxidized in the hydrogen generator 13 before being supplied to the carbon separator 7, and at least a part of the oxidizing power of the reducing agent is restored. Therefore, in the third embodiment, the oxidation of the carbon-containing material in the carbon separator 7 is easily promoted as compared with the first embodiment and the second embodiment that do not use the hydrogen generator 13.

  The hydrogen-containing gas h in the hydrogen generator 13 is discharged from the upper part of the hydrogen generator 13. The hydrogen-containing gas h discharged from the upper part of the hydrogen generator 13 is supplied to the third powder separator 8c. In the third powder separator 8c, the solid content remaining in the hydrogen-containing gas h is separated. The separated solid content is discharged from the lower part of the third powder separator 8c. The solid content may include, for example, a reducing agent, an oxidizing agent, a carbon-containing material, or ash.

  The hydrogen-containing gas h separated from the solid content in the third powder separator 8c is supplied to the third heat exchanger 14c. In the third heat exchanger 14c, water is heated with the hydrogen-containing gas h to generate high-temperature steam. This steam is supplied to the turbine 20a.

  The hydrogen-containing gas h cooled by the third heat exchanger 14c is recovered. Fine solids (for example, ash) remaining in the recovered hydrogen-containing gas h may be removed with a dust collector. Subsequently, components (for example, hydrogen sulfide) other than hydrogen contained in the hydrogen-containing gas h may be removed. By removing components other than hydrogen from the hydrogen-containing gas h, high-purity hydrogen can be obtained. High-purity hydrogen is used, for example, for the production of chemicals, the refinement of petroleum, or the iron making.

[Fourth embodiment]
The fourth embodiment of the present invention is the same as the third embodiment except for the matters described below. According to the fourth embodiment, similarly to the third embodiment, it is possible to prevent the carbon-containing material from being supplied from the fuel reactor 6 to the air reactor 5.

  As shown in FIG. 4, the power generation device 100 d according to the fourth embodiment includes a chemical loop combustion device 10 d and a turbine generator 20. In the chemical loop combustion apparatus 10 d according to the fourth embodiment, the hydrogen generator 13 is provided in the middle of the third line 3. In the fourth embodiment, the reducing agent from which the carbon-containing material has already been removed in the carbon separator 7 is supplied to the hydrogen generator 13 through the third line 3. Therefore, in the hydrogen generator 13, at least a part of the reducing agent is partially oxidized by water vapor to generate hydrogen, but the carbon-containing substance is hardly oxidized. That is, the hydrogen-containing gas h generated in the hydrogen generator 13 is unlikely to contain carbon dioxide and carbon monoxide. Therefore, the purity of hydrogen finally obtained in the fourth embodiment tends to be higher than the purity of hydrogen obtained in the third embodiment.

  The reducing agent in the hydrogen generator 13 and the partially oxidized reducing agent are supplied from the lower part of the hydrogen generator 13 to the lower part of the air reactor 5 through the third line 3. When the oxidant is generated in the hydrogen generator 13, the oxidant is also supplied from the hydrogen generator 13 to the air reactor 5 through the third line 3.

[Other Embodiments]
As mentioned above, although embodiment of this invention was described, this invention is not limited to said embodiment.

  For example, any of the chemical loop combustion apparatuses according to the above embodiments may further include a fifth line branched from the fourth line 4 and connected to the second line 2. Oxidant may be fed from the air reactor 5 to the second line 2 through the fifth line. As a result, the oxidation (gasification) of the carbon-containing material by the oxidizing agent starts from the time before the carbon-containing material in the second line 2 is supplied to the carbon separator 7. It becomes easy to be removed from the reducing agent.

  The high temperature gas g3 separated from the oxidant in the first powder separator 8a may be directly supplied to the turbine 20a without being supplied to the first heat exchanger 14a. In this case, the turbine 20a may be a gas turbine instead of a steam turbine.

  Before supplying the air A to the air reactor 5, it may be heated in the first heat exchanger 14a, the second heat exchanger 14b, or the third heat exchanger 14c. A part of the water vapor generated in the first heat exchanger 14a, the second heat exchanger 14b, or the third heat exchanger 14c is supplied to any one of the fuel reactor 6, the carbon separator 7, and the hydrogen generator 13. You can do it.

  The fuel reactor 6, the carbon separator 7, or the hydrogen generator 13 may be a moving bed reactor.

  According to the chemical loop combustion apparatus, the power generation apparatus, and the chemical loop combustion method according to the present invention, for example, carbon dioxide generated in combustion of coal or power generation using coal can be easily recovered.

DESCRIPTION OF SYMBOLS 1 1st line 2 2nd line 3 3rd line 4 4th line 5 Air reactor 6 Fuel reactor 7 Carbon separator 8a First powder separator 8b Second powder separator 8c Third powder separator 9 Measuring means 10a, 10b, 10c, 10d Chemical loop combustor 11 Controller 12 Valve 13 Hydrogen generator 14a First heat exchanger 14b Second heat exchanger 14c Third heat exchanger 20 Turbine generator 20a Turbine 20b Generator 100a , 100b, 100c, 100d Power generation device A Air F Fuel g1 First gas G1 First fluidized gas g2 Second gas G2 Second fluidized gas g3 Gas h Hydrogen-containing gas

Claims (6)

An air reactor that oxidizes a solid reducing agent containing a metal with oxygen in the air to produce the solid oxidizing agent containing the metal and oxygen;
A fuel reactor that oxidizes a fuel containing carbon with the oxidant to generate a gas containing carbon dioxide and the reducing agent;
A carbon-containing substance derived from the fuel and the reducing agent are supplied from the fuel reactor, oxidize the carbon-containing substance to generate a gas containing carbon dioxide, and separate the gas from the reducing agent. A carbon separator,
A first line for supplying the oxidant generated in the air reactor to the fuel reactor;
A second line for supplying the carbon-containing material and the reducing agent from the fuel reactor to the carbon separator;
A third line for supplying the reducing agent from the carbon separator to the air reactor;
A fourth line for supplying the oxidant produced in the air reactor to the carbon separator;
With
In the carbon separator, the carbon-containing material is oxidized by the oxidant supplied through the fourth line to generate the gas.
Chemical loop combustion device. Measuring means for measuring the content of carbon dioxide in the gas discharged from the air reactor;
A control device for controlling the amount of the oxidant supplied from the air reactor to the carbon separator through the fourth line based on the carbon dioxide content measured by the measuring means;
Further comprising
The chemical loop combustion apparatus according to claim 1. A hydrogen generator that is provided in the middle of the second line or the third line and that partially oxidizes at least a part of the reducing agent with water vapor to generate at least hydrogen;
The chemical loop combustion apparatus according to claim 1 or 2. Provided in the middle of the first line, separates the oxidant and gas supplied from the air reactor, and supplies the separated oxidant to at least one of the fuel reactor and the carbon separator A powder separator
The chemical loop combustion apparatus as described in any one of Claims 1-3. The chemical loop combustion apparatus according to any one of claims 1 to 4,
A turbine generator driven by gas supplied from the chemical loop combustion device;
Comprising
Power generation device. Oxidizing a solid reducing agent containing a metal with oxygen in the air in an air reactor to produce a solid oxidizing agent containing the metal and oxygen;
Supplying the oxidant from the air reactor to a fuel reactor;
Oxidizing the fuel containing carbon with the oxidant in the fuel reactor to generate a gas containing carbon dioxide and the reducing agent;
Supplying a carbon-containing substance derived from the fuel and the reducing agent from the fuel reactor to a carbon separator;
Supplying the oxidant from the air reactor to the carbon separator;
In the carbon separator, the step of oxidizing the carbon-containing substance with the oxidant supplied from the air reactor to generate a gas containing carbon dioxide, and separating the gas from the reducing agent;
Supplying the reducing agent from the carbon separator to the air reactor;
Comprising
Chemical loop combustion method.

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