JP6944798B2 - Chemical looping combustion furnace and chemical looping combustion system - Google Patents

Description

The present invention relates to a chemical looping combustion furnace and a chemical looping combustion system.

Chemical Looping Combustion (CLC) system (hereinafter referred to as CLC system) is, for example, as disclosed in Patent Document 1, an air reaction chamber, a combustion reaction chamber, an air reaction chamber, and a combustion reaction chamber. It is provided with two pipes connecting the two pipes and oxygen carrier particles circulating between the two pipes and circulating between the air reaction chamber and the combustion reaction chamber.

A fluidized bed is formed inside the air reaction chamber and the combustion reaction chamber. In the air reaction chamber, oxygen carrier particles are reacted with air in a fluidized bed to oxidize and generate heat. In the combustion reaction chamber, solid fuel such as coal is burned and oxygen carrier particles are reduced by the high-temperature oxygen carrier particles oxidized in the air reaction chamber in the fluidized bed. As a result, the solid fuel is burned without coming into direct contact with air, so that the components of the exhaust gas from the combustion reaction chamber are almost only carbon dioxide (CO ₂ ) and water vapor (H ₂ O).

_{Therefore, in the CLC system, it is possible to prevent the generation of nitrogen oxides (NO x} ) due to the combustion of solid fuel, and it is possible to easily separate and recover carbon dioxide from the exhaust gas. The CLC system is considered to be a promising candidate for CCS technology for separating and recovering carbon dioxide from the exhaust gas of equipment such as thermal power plants.

Japanese Unexamined Patent Publication No. 2013-194213

In the CLC system disclosed in Patent Document 1, there is a risk that the equipment will be large in size due to its structure. In addition, since it is necessary to connect the air reaction chamber and the combustion reaction chamber with two pipes and allow oxygen carrier particles to flow in each pipe at a predetermined flow velocity, the equipment structure becomes complicated and the operation reliability deteriorates. There is a risk of

Therefore, it is an object of the present invention to improve the operation reliability by preventing the equipment from becoming large in size and simplifying the equipment structure in the CLC system that burns solid fuel.

In order to solve the above problems, the chemical looping combustion furnace according to one aspect of the present invention is an internal circulation type and flows over an oxidation chamber, a reduction chamber, a lower part of the oxidation chamber and a lower part of the reduction chamber. The fluidized bed containing the oxygen carrier particles, the circulation portion for circulating the oxygen carrier particles between the oxidation chamber and the reduction chamber, the upper space in the oxidation chamber and the upper space in the reduction chamber are partitioned, and the lower end is the said. It is provided with a single furnace body in which a partition wall arranged in the flow bed is formed inside, and in the oxidation chamber, the oxygen carrier particles are made to flow by an oxidizing first supply gas supplied from the outside. , The first supply gas and the oxygen carrier particles are mixed, the oxygen carrier particles are oxidized by the first supply gas, and in the reduction chamber, the second supply gas supplied from the outside and non-oxidizing is used to oxidize the oxygen carrier particles. The oxygen carrier particles oxidized in the oxidation chamber are mixed with the solid fuel while flowing, and the solid fuel is burned by the oxygen carrier particles oxidized in the oxidation chamber, and the oxygen oxidized in the oxidation chamber is burned. The carrier particles are reduced, and the circulation portion is supplied from the outside and a first flow path for circulating the oxygen carrier particles oxidized in the oxidation chamber to the reduction chamber by a second supply gas supplied from the outside. It has a second flow path for circulating the oxygen carrier particles reduced in the reduction chamber to the oxidation chamber by the second supply gas.

According to the above configuration, by forming the oxidation chamber, the reduction chamber, the fluidized bed, the circulation part, and the partition wall inside a single furnace body, the piping for connecting the oxidation chamber and the reduction chamber can be omitted. , The amount of oxygen carrier particles can be reduced, and the oxidation chamber and reduction chamber can be compactly configured. Further, since the oxygen carrier particles are circulated in the circulation portion by using the same gas as the non-oxidizing second supply gas for mixing the solid fuel and the oxygen carrier particles oxidized in the oxidation chamber in the reduction chamber, oxidation is performed. It is possible to prevent unnecessary components from being included in the composition of the exhaust gas discharged from the chamber or the reduction chamber. Therefore, in a CLC system including a CLC furnace for burning solid fuel, it is possible to prevent the equipment from becoming large in size, simplify the equipment structure, and prevent a decrease in operation reliability.

The circulation portion may be arranged adjacent to the oxidation chamber and in the reduction chamber, and the second supply gas may be supplied into the circulation portion from the lower side to the upper side of the fluidized bed. As a result, the carbon component of the solid fuel in the reduction chamber is prevented from entering the oxidation chamber via the circulation portion by the flow of the second supply gas supplied into the circulation portion, and the exhaust gas discharged from the oxidation chamber is prevented. It prevents carbon components from being mixed into the composition.

The oxygen carrier particles oxidized in the oxidation chamber are supplied to the reduction chamber from above the fluidized bed in the reduction chamber by a second supply gas through the first flow path, and the solid fuel flows into the reduction chamber. It may be supplied into the reduction chamber from the bottom of the floor.

As a result, the contact time between the oxygen carrier particles oxidized in the oxidation chamber and the solid fuel can be secured for a long time, so that the combustion of the solid fuel can be promoted, and carbon monoxide (CO) and hydrogen (H) generated during the combustion of the solid fuel can be promoted. It is possible to prevent unburned gas such as _{2) from being discharged from the reduction chamber.} Therefore, even in a CLC system having a simplified equipment structure, carbon dioxide can be easily recovered from the exhaust gas.

The first flow path extends in the vertical direction inside the fluidized bed, and the oxygen carrier particles oxidized in the oxidation chamber are directed by the second supply gas from the lower side to the upper side of the fluidized bed. It may flow through the flow path. As a result, the horizontal dimensions of the CLC furnace can be easily made compact, and the oxygen carrier particles oxidized in the oxidation chamber can be easily supplied to the fluidized bed in the reduction chamber from above.

The oxygen carrier particles reduced in the reduction chamber are supplied to the fluidized bed in the oxidation chamber by the second supply gas through the second flow path, and the first supply gas is supplied from below the oxidation chamber. It may be supplied to the oxidation chamber.

In this way, by using the second flow path, the oxygen carrier particles reduced in the reduction chamber are supplied into the fluidized bed in the oxidation chamber, and the first supply gas is supplied from below the oxidation chamber into the oxidation chamber. , The oxygen carrier particles and the first supply gas can be easily mixed in the oxidation chamber.

The second flow path is formed in the horizontal direction below the first flow path, and the oxygen carrier particles reduced in the reduction chamber are horizontally formed from the fluidized bed in the reduction chamber by the second supply gas. The second flow path may be circulated in the direction. As a result, the oxygen carrier particles reduced along with the combustion of the solid fuel in the fluidized bed in the reduction chamber can be easily supplied to the oxidation chamber side.

The second flow path may have a bent portion that extends upward and then bends downward from the reduction chamber side toward the oxidation chamber side. As a result, the bent portion of the second flow path is used to prevent the solid fuel from flowing from the reduction chamber side to the oxidation chamber side through the second flow path, and the carbon component is added to the exhaust gas discharged from the oxidation chamber side. Can be satisfactorily prevented from being mixed.

The first flow path and the second flow path may be partitioned from each other. As a result, the first flow path and the second flow path can be physically separated, and the fluidized beds flowing through the first flow path and the second flow path are mixed with each other, so that the second flow flows from the reduction chamber side to the oxidation chamber side. The inflow of solid fuel through the road can be satisfactorily prevented.

The first supply gas may be air or oxygen-enriched air, and the second supply gas may be water vapor or carbon dioxide gas, or a mixture of water vapor and carbon dioxide gas. As a result, the first supply gas and the second supply gas can be obtained at low cost, and even if the second supply gas for circulating oxygen carrier particles flows into the reduction chamber, it is discharged from the reduction chamber side. It is possible to prevent the composition of the exhaust gas to be changed, and it is possible to prevent the efficiency of separating / recovering carbon dioxide from the exhaust gas from being lowered.

The chemical looping combustion system according to another aspect of the present invention includes the chemical looping combustion furnace according to any one of the above, a first supply path for supplying a first supply gas to the oxidation chamber, and a second supply passage into the reduction chamber. The second supply path for supplying the supply gas, the third supply path for supplying the second supply gas into the circulation section, the flow rate of the first supply gas flowing through the first supply path, and the second supply path. It is provided with a flow rate adjusting valve capable of adjusting the flow rate of the second supply gas flowing through the third supply path independently of the flow rate of the second supply gas flowing through.

As a result, the flow rate of the oxygen carrier particles flowing through the circulation section can be easily adjusted while maintaining the reaction conditions of the oxidation reaction of the oxygen carrier particles in the oxidation chamber and the combustion reaction of the solid fuel in the reduction chamber, and the solid. An internal circulation type CLC furnace that burns fuel can be driven under optimum conditions.

According to each aspect of the present invention, in a CLC system that burns solid fuel, it is possible to improve the operation reliability by preventing the equipment from becoming large and simplifying the equipment structure.

It is the schematic of the CLC system which concerns on 1st Embodiment. It is a partial schematic view of the CLC furnace which concerns on the modification of 1st Embodiment. It is the schematic of the CLC system which concerns on 2nd Embodiment. It is a partial schematic view of the CLC furnace which concerns on the modification of 2nd Embodiment. It is a perspective view which shows the internal structure of the CLC furnace which concerns on 3rd Embodiment. It is a perspective view which shows the internal structure of the CLC furnace which concerns on the modification of 3rd Embodiment.

Hereinafter, each embodiment will be described with reference to the drawings.

(First Embodiment)
FIG. 1 is a schematic view of the CLC system 1 according to the first embodiment. As shown in FIG. 1, the CLC system 1 includes a CLC furnace 2, a control device 3, a first heat exchanger 4, a second heat exchanger 5, a dehydrator 6, a solid fuel supply path R1, a first supply path R2, and the like. A second supply path R3, a third supply path R4, a first discharge path R5, and a second discharge path R6 are provided.

The CLC furnace 2 includes a single furnace body in which an oxidation chamber 2a, a reduction chamber 2b, a fluidized bed 2f, a circulation portion 2j, and a partition wall 2c are formed inside. The CLC furnace 2 is an internal circulation type, and oxygen carrier particles (fluid medium) contained in the fluidized bed 2f circulate in the oxidation chamber 2a and the reduction chamber 2b inside the CLC furnace 2. Inside the CLC furnace 2 of the present embodiment, a hearth 2d, a plurality of nozzles 2e, and a wind box 2g to 2i are further formed.

The oxidation chamber 2a and the reduction chamber 2b are provided in the CLC furnace 2 with the partition wall 2c separated from each other. In the oxidation chamber 2a, the oxygen carrier particles are mixed by the first supply gas and the oxygen carrier particles are mixed while the oxygen carrier particles are made to flow by the oxidizing first supply gas supplied from the outside, and the oxygen carrier particles are oxidized by the first supply gas. do. The first supply gas is, for example, air or oxygen-enriched air. The first supply gas of the present embodiment is air, and the oxidation chamber 2a is an air reaction chamber in which oxygen carrier particles react with air.

In the reduction chamber 2b, the oxygen carrier particles oxidized in the oxidation chamber 2a are mixed with the solid fuel while flowing by the second supply gas supplied from the outside and non-oxidizing, and the oxygen carriers oxidized in the oxidation chamber 2a. The particles burn the solid fuel and reduce the oxidized oxygen carrier particles in the oxidation chamber 2a. The reduction chamber 2b is a combustion reaction chamber in which the solid fuel undergoes a combustion reaction. The solid fuel is supplied to the reduction chamber 2b from the outside. The solid fuel is, but is not limited to, coal in this embodiment. The solid fuel may be, for example, biomass, or may be a solid containing a carbon component. The second supply gas is, for example, water vapor or carbon dioxide gas, or a mixture of water vapor and carbon dioxide gas. The second supply gas of this embodiment is water vapor.

The partition wall 2c partitions the upper space 7 in the oxidation chamber 2a and the upper space 8 in the reduction chamber 2b. The lower end of the partition wall 2c is arranged in the fluidized bed 2f. As a result, the upper spaces (freeboards) 7 and 8 are separated from each other, and gas mixing between the upper spaces 7 and 8 is suppressed. The inner wall of the oxidation chamber 2a and the reduction chamber 2b and the partition wall 2c are, for example, made of a refractory material or a heat-resistant metal material.

The hearth 2d is arranged below the oxidation chamber 2a and the reduction chamber 2b. The plurality of nozzles 2e are dispersedly arranged on the upper surface of the hearth 2d. The fluidized bed 2f is arranged above the hearth 2d. The fluidized bed 2f flows downward in the oxidation chamber 2a and downward in the reduction chamber 2b. The oxygen carrier particles contained in the fluidized bed 2f contain iron. As an example, the main component of the oxygen carrier particles is Fe ₂ O _{3 (ferrous oxide (III)) in the state of being oxidized in the oxidation chamber 2a, and Fe 3} O ₄ (in the state of being reduced in the reduction chamber 2b). It is triiron tetroxide (II, III)). The material of the oxygen carrier particles is not limited. The oxygen carrier particles may contain metals such as nickel, copper, manganese, or aluminum.

The circulation unit 2j circulates oxygen carrier particles in the oxidation chamber 2a and the reduction chamber 2b. The circulation portion 2j has a first flow path 2k and a second flow path 2l. Both ends of the first flow path 2k and the second flow path 2l are connected to the oxidation chamber 2a and the reduction chamber 2b, respectively. A second supply gas is supplied to the circulation portion 2j from the outside.

In the first flow path 2k, the oxygen carrier particles oxidized in the oxidation chamber 2a are circulated to the reduction chamber 2b by the second supply gas supplied from the outside into the circulation portion 2j. In the second flow path 2l, the oxygen carrier particles reduced in the reduction chamber 2b are circulated to the oxidation chamber 2a by the second supply gas supplied from the outside into the circulation portion 2j.

In the present embodiment, the circulation unit 2j is arranged adjacent to the oxidation chamber 2a and in the reduction chamber 2b. The second supply gas is supplied to the circulation portion 2j from the lower side to the upper side of the fluidized bed 2f. Further, the oxygen carrier particles oxidized in the oxidation chamber 2a are supplied into the reduction chamber 2b from above the fluidized bed 2f in the reduction chamber 2b through the first flow path 2k.

Specifically, a guide wall 2 m is formed inside the CLC furnace 2. The guide wall 2m extends in the vertical direction at a position separated from the partition wall 2c on the reduction chamber 2b side. The guide wall 2m guides the oxygen carrier particles oxidized in the oxidation chamber 2a to and from the partition wall 2c. As an example, the lower end of the guide wall 2m is arranged below the lower end of the partition wall 2c while being separated upward from the hearth 2d. The first flow path 2k is formed between the partition wall 2c and the guide wall 2m. As a result, the first flow path 2k extends in the vertical direction inside the fluidized bed 2f. The oxygen carrier particles oxidized in the oxidation chamber 2a flow through the first flow path 2k from the lower side to the upper side of the fluidized bed 2f.

The second flow path 2l is formed in the horizontal direction below the first flow path 2k. The oxygen carrier particles reduced in the reduction chamber 2b circulate in the second flow path 2l in the horizontal direction from the fluidized bed 2f in the reduction chamber 2b.

The air box 2g is provided below the region corresponding to the oxidation chamber 2a of the hearth 2d. The air box 2h is provided below the region corresponding to the reduction chamber 2b of the hearth 2d. The air box 2i is provided below the region corresponding to the circulation portion 2j of the hearth 2d.

The solid fuel supply path R1 supplies solid fuel into the reduction chamber 2b. The solid fuel supply path R1 is connected to the lower side portion of the reduction chamber 2b. As a result, the solid fuel is supplied into the reduction chamber 2b from the bottom of the fluidized bed 2f. The bottom of the fluidized bed 2f referred to here is preferably a region from the upper surface of the furnace bed 2d to 1/3 of the layer height of the fluidized bed 2f on the reduction chamber 2b side in the stopped CLC furnace 2. It is more desirable that the region is from the upper surface of the hearth 2d to 1/5 of the layer height of the fluidized bed 2f on the reduction chamber 2b side.

The first supply path R2 supplies the first supply gas into the oxidation chamber 2a. As a result, the first supply gas is supplied into the oxidation chamber 2a from below the oxidation chamber 2a. The downstream end of the first supply path R2 is connected to the air box 2g. The second supply path R3 supplies the second supply gas into the reduction chamber 2b. The downstream end of the second supply path R3 is connected to the air box 2h. The third supply path R4 supplies the second supply gas into the circulation unit 2j. The downstream end of the third supply path R4 is connected to the air box 2i.

A flow rate adjusting valve V1 capable of adjusting the flow rate of the first supply gas flowing through the first supply path R2 is provided in the middle of the first supply path R2. A flow rate adjusting valve V2 capable of adjusting the flow rate of the second supply gas flowing through the second supply path R3 is provided in the middle of the second supply path R3. A flow rate adjusting valve V3 capable of adjusting the flow rate of the second supply gas flowing through the third supply path R4 is provided in the middle of the third supply path R4.

In the present embodiment, the flow rate adjusting valve V3 supplies the third supply independently of the flow rate of the first supply gas flowing through the first supply path R2 and the flow rate of the second supply gas flowing through the second supply path R3. It is possible to adjust the flow rate of the second supply gas flowing through the road R4. Further, a blower (not shown) for circulating gas is provided in the middle of each of the first supply path R2, the second supply path R3, and the third supply path R4.

The first discharge path R5 discharges the first exhaust gas generated by the oxidation of the oxygen carrier particles to the outside of the oxidation chamber 2a. The upstream end of the first discharge path R5 is connected to the oxidation chamber 2a. The first heat exchanger 4 is provided in the middle of the first discharge path R5. The first heat exchanger 4 recovers heat from the first exhaust gas.

The second exhaust path R6 discharges the second exhaust gas generated by the combustion of the solid fuel to the outside of the reduction chamber 2b. The upstream end of the second discharge path R6 is connected to the reduction chamber 2b. The second heat exchanger 5 is provided in the middle of the second discharge path R6. The second heat exchanger 5 recovers heat from the second exhaust gas.

The dehydrator 6 is provided on the downstream side in the distribution direction of the second exhaust gas with respect to the second heat exchanger 5 of the second exhaust path R6. The dehydrator 6 dehydrates the second exhaust gas. The component of the second exhaust gas is almost only carbon dioxide due to the dehydration of the second exhaust gas. The second exhaust gas dehydrated by this is recovered as carbon dioxide.

The control device 3 is connected to the flow rate adjusting valves V1 to V3. In the present embodiment, the control device 3 individually controls the flow rate adjusting valves V1 to V3. The control device 3 is, for example, a computer including a CPU, a ROM, and a RAM. The control program is stored in the ROM. The control device 3 controls the flow rate adjusting valves V1 to V3 based on the control program.

During operation of the CLC system 1, the first supply gas that has passed through the first supply path R2 is ejected into the oxidation chamber 2a from a plurality of nozzles 2e arranged corresponding to the oxidation chamber 2a via the air box 2g. .. The first supply gas is mixed as bubbles in the fluidized bed 2f in the oxidation chamber 2a.

The oxygen carrier particles on the oxidation chamber 2a side are oxidized by the first supply gas ejected from the plurality of nozzles 2e in the oxidation chamber 2a to generate heat. The first exhaust gas generated by the oxidation of the oxygen carrier particles passes through the upper space 7 and is discharged to the outside of the oxidation chamber 2a. When air is used as the first supply gas, the components of the first exhaust gas are almost only nitrogen (N ₂ ) and oxygen (O ₂ ). Since the oxidation temperature of the oxygen carrier particles is not so high, there is little possibility that nitrogen oxides will be generated by the oxidation of the oxygen carrier particles even if the first supply gas containing a nitrogen component is used.

Further, the second supply gas that has passed through the third supply path R4 passes through the air box 2i and is transmitted from the plurality of nozzles 2e arranged corresponding to the circulation portion 2j to the first flow path 2k and the second flow path 2l. It spouts toward. The oxygen carrier particles oxidized in the oxidation chamber 2a pass below the partition wall 2c and move to the lower end of the first flow path 2k. Then, due to the momentum of the second supply gas supplied into the circulation unit 2j, the first flow path 2k is circulated from the lower side to the upper side of the fluidized bed 2f in the circulation unit 2j, and the fluidized bed 2f in the reduction chamber 2b is circulated. Is supplied from above.

Further, the second supply gas that has passed through the second supply path R3 is ejected into the reduction chamber 2b from a plurality of nozzles 2e arranged corresponding to the reduction chamber 2b via the air box 2h. The second supply gas is mixed as bubbles in the fluidized bed 2f in the reduction chamber 2b. Further, the solid fuel that has passed through the solid fuel supply path R1 is supplied into the reduction chamber 2b from the bottom of the fluidized bed 2f.

The oxygen carrier particles oxidized in the oxidation chamber 2a and the solid fuel are mixed by the second supply gas ejected from the plurality of nozzles 2e in the reduction chamber 2b. As a result, the solid fuel is burned by the oxygen carrier particles oxidized in the oxidation chamber 2a, and the oxygen carrier particles are reduced. The second exhaust gas generated by the combustion of the solid fuel and the reduction of the oxygen carrier particles passes through the upper space 8 and is discharged to the outside of the reduction chamber 2b. When water vapor is used as the second supply gas, the second exhaust gas components are almost only carbon dioxide and water vapor.

The oxygen carrier particles reduced in the reduction chamber 2b flow from the upper side to the lower side of the fluidized bed 2f in the reduction chamber 2b. Then, it is supplied into the fluidized bed 2f in the oxidation chamber 2a through the second flow path 2l formed below the first flow path 2k. The oxygen carrier particles flow through the fluidized bed 2f in the oxidation chamber 2a from the lower side to the upper side, and then pass under the partition wall 2c and flow through the first flow path 2k again.

In this way, inside the CLC furnace 2, the flow of oxygen carrier particles is formed by the second supply gas supplied into the circulation portion 2j, so that the oxygen carrier particles are generated over the oxidation chamber 2a side and the reduction chamber 2b side. It is circulated efficiently and promotes the combustion of solid fuel and the oxidation / reduction of oxygen carrier particles.

Further, the second supply gas supplied from the plurality of nozzles 2e arranged corresponding to the circulation portion 2j is ejected from the lower side to the upper side, so that the second supply gas functions as a separate gas and is reduced. The unburned carbon component in the chamber 2b is prevented from entering the oxidation chamber 2a. Therefore, in the CLC furnace 2, the carbon component is burned in the oxidation chamber 2a and the carbon component is mixed in the composition of the first exhaust gas, or the combustion rate (carbon conversion rate) of the solid fuel in the reduction chamber 2b is lowered. However, it is prevented by a relatively simple configuration. As described above, the CLC furnace 2 is provided with a separator structure (carbon separator) for preventing the unburned carbon component in the reduction chamber 2b from entering the oxidation chamber 2a.

As described above, in the CLC furnace 2, the oxidation chamber 2a, the reduction chamber 2b, the fluidized bed 2f, the circulation portion 2j, and the partition wall 2c are formed inside a single furnace body to reduce the oxidation chamber 2a and the reduction chamber 2a. The piping for connecting to the chamber 2b can be omitted, the amount of oxygen carrier particles can be reduced, and the oxidation chamber 2a and the reduction chamber 2b can be compactly configured. Further, the oxygen carrier particles are circulated through the circulation portion 2j by using the same gas as the non-oxidizing second supply gas for mixing the solid fuel and the oxygen carrier particles oxidized in the oxidation chamber 2a in the reduction chamber 2b. Therefore, it is possible to prevent components such as nitrogen oxides and carbon oxides that are unnecessary for the composition of the exhaust gas discharged from the oxidation chamber 2a or the reduction chamber 2b from being included. Therefore, in the CLC system 1 provided with the CLC furnace 2 for burning solid fuel, it is possible to prevent the equipment from becoming large in size, simplify the equipment structure, and prevent the operation reliability from deteriorating. Therefore, the CLC system 1 can be effectively used as, for example, a small and medium-sized furnace for industrial power generation on a small and medium-sized industrial scale, and a combustion furnace for burning garbage and biomass.

Further, since the piping for connecting the oxidation chamber 2a and the reduction chamber 2b is not required, for example, the gas and control to be supplied for flowing and transporting the oxygen carrier particles to the piping at high speed are not required, and oxygen is not required. It is possible to avoid the problem that the piping is corroded or worn due to contact with the carrier particles. As a result, the control of the CLC system 1 can be simplified, and the CLC system 1 can be driven economically and stably.

Further, since the CLC furnace 2 is an internal circulation type, the oxidation chamber 2a and the reduction chamber 2b are connected by two pipes, and oxygen carrier particles are circulated in each pipe at a predetermined flow velocity, as compared with the case where the oxygen carrier particles are circulated in each pipe. The flow velocity of the oxygen carrier particles can be set to a low speed. Therefore, it is possible to operate the CLC system 1 while suppressing the supply amount of the second supply gas to the circulation unit 2j.

Further, since the circulation portion 2j is adjacent to the oxidation chamber 2a and is arranged in the reduction chamber 2b, and the second supply gas is supplied to the circulation portion 2j from the lower side to the upper side of the fluidized bed 2f, the inside of the reduction chamber 2b. The carbon component of the solid fuel is prevented from entering the oxidation chamber 2a via the circulation portion 2j by the flow of the second supply gas supplied into the circulation portion 2j, and the exhaust gas discharged from the oxidation chamber 2a. The carbon component is prevented from being mixed in the composition of.

Further, the oxygen carrier particles oxidized in the oxidation chamber 2a are supplied into the reduction chamber 2b from above the fluidized bed 2f in the reduction chamber 2b by the second supply gas through the first flow path 2k, and the solid fuel is supplied. By supplying from the bottom of the fluidized bed 2f into the reduction chamber 2b, for example, when both the oxygen carrier particles oxidized in the oxidizing chamber 2a and the solid fuel are supplied from the bottom of the fluidized bed 2f into the reducing chamber 2b. It is possible to secure a long contact time between the oxygen carrier particles oxidized in the oxidation chamber 2a and the solid fuel. Therefore, the combustion of the solid fuel can be promoted, and the unburned gas such as carbon monoxide and hydrogen generated during the combustion of the solid fuel can be prevented from being discharged from the reduction chamber 2b. Therefore, even in the CLC system 1 having a simplified equipment structure, carbon dioxide can be easily recovered from the second exhaust gas.

Further, the first flow path 2k extends in the vertical direction inside the fluidized bed 2f, and the oxygen carrier particles oxidized in the oxide chamber 2a are moved from the lower side to the upper side of the fluidized bed 2f in the oxide chamber 2a by the second supply gas. Since the first flow path 2k is circulated toward the direction, the horizontal dimension of the CLC furnace 2 can be easily made compact, and the oxygen carrier particles oxidized in the oxidation chamber 2a are supplied to the fluidized bed 2f in the reduction chamber 2b from above. It can be done easily.

Further, the oxygen carrier particles reduced in the reduction chamber 2b are supplied to the fluidized bed 2f in the oxidation chamber 2a by the second supply gas through the second flow path 2l, and the first supply gas is supplied to the oxidation chamber 2a. Since it is supplied into the oxidation chamber 2a from below, the oxygen carrier particles reduced in the reduction chamber 2b are supplied into the fluidized bed 2f in the oxidation chamber 2a by using the second flow path 2l, and the first supply gas is supplied. Is supplied into the oxidation chamber 2a from below the oxidation chamber 2a, so that the oxygen carrier particles and the first supply gas can be easily mixed in the oxidation chamber 2a.

Further, the second flow path 2l is formed in the horizontal direction below the first flow path 2k, and the oxygen carrier particles reduced in the reduction chamber 2b are generated in the fluidized bed 2f in the reduction chamber 2b by the second supply gas. Since the second flow path 2l flows in the horizontal direction from the above, the oxygen carrier particles reduced along with the combustion of the solid fuel in the fluidized bed 2f in the reduction chamber 2b can be easily supplied to the oxidation chamber 2a side.

Further, since the first supply gas is air and the second supply gas is water vapor, the first supply gas and the second supply gas can be obtained at low cost, and oxygen carrier particles can be generated in the circulation portion 2j. Even if the second supply gas for distribution flows into the reduction chamber 2b, it is possible to prevent the composition of the second exhaust gas discharged from the reduction chamber 2b side from changing, and the efficiency of separating and recovering carbon dioxide from the second exhaust gas is improved. It can be prevented from decreasing.

Further, the CLC system 1 distributes the third supply path R4 independently of the flow rate of the first supply gas flowing through the first supply path R2 and the flow rate of the second supply gas flowing through the second supply path R3. Since the flow control valve V3 capable of adjusting the flow rate of the second supply gas is provided, the reaction conditions of the oxidation reaction of the oxygen carrier particles in the oxidation chamber 2a and the combustion reaction of the solid fuel in the reduction chamber 2b are maintained. , The flow rate of the oxygen carrier particles flowing through the circulation unit 2j can be easily adjusted, and the internal circulation type CLC furnace 2 for burning solid fuel can be driven under optimum conditions.

(Modified example of the first embodiment)
FIG. 2 is a partial schematic view of the CLC furnace 12 according to the modified example of the first embodiment. As shown in FIG. 2, auxiliary guide walls 2p and 2n are formed inside the CLC furnace 12. The auxiliary guide wall 2p extends upward from the hearth 2d at a position separated from the guide wall 2m on the side opposite to the oxidation chamber 2a side. The upper end position of the auxiliary guide wall 2p is located above the lower end of the guide wall 2m and below the upper end of the guide wall 2m.

The auxiliary guide wall 2n extends horizontally from the wall surface of the guide wall 2 m opposite to the oxidation chamber 2a side above the upper end of the auxiliary guide wall 2p, and then the oxidation chamber 2a with respect to the auxiliary guide wall 2p. It extends downward at a position separated from the side. The lower end of the auxiliary guide wall 2n is located above the hearth 2d.

The second flow path 2l extends between the auxiliary guide walls 2p and 2n. As a result, the second flow path 2l has a bent portion 2q that bends from the reduction chamber 2b side toward the oxidation chamber 2a side so as to extend upward and then downward.

In the CLC furnace 12, the bent portion 2q functions as a separator structure for further preventing carbon component intrusion. That is, since the second flow path 2l has the bent portion 2q, the bent portion 2q is used to prevent the solid fuel from flowing from the reduction chamber 2b side to the oxidation chamber 2a side through the second flow path 2l. It is possible to better prevent the carbon component from being mixed in the exhaust gas composition discharged from the oxidation chamber 2a side.

(Second Embodiment)
The second embodiment will be described focusing on the difference from the first embodiment. FIG. 3 is a schematic view of the CLC system 21 according to the second embodiment. As shown in FIG. 3, inside the CLC furnace 22 included in the CLC system 21, two oxidation chambers 2a and two circulation portions 2j are arranged on both sides of a single reduction chamber 2b in the horizontal direction.

Each oxidation chamber 2a is provided with a first supply path R2 and a flow rate adjusting valve V1. Further, each circulation portion 2j is provided with a third supply path R4 and a flow rate adjusting valve V3. The control device 3 individually controls all the flow rate adjusting valves V1 to V3. The CLC system 21 having the above configuration can be expected to have the same effect as the CLC system 1 of the first embodiment.

(Modified example of the second embodiment)
FIG. 4 is a partial schematic view of the CLC furnace 32 according to the modified example of the second embodiment. As shown in FIG. 4, the CLC furnace 32 has a CLC furnace 22 as a basic structure, and two second flow paths 2l each have a bent portion 2q. Even in the CLC furnace 32 having such a configuration, it is possible to satisfactorily prevent the carbon component from being mixed in the exhaust gas discharged from the oxidation chamber 2a side, as in the modified example of the first embodiment.

(Third Embodiment)
FIG. 5 is a perspective view showing the internal structure of the CLC furnace 42 according to the third embodiment. As shown in FIG. 5, the CLC furnace 42 has a plurality of distribution pipes 15 provided in the circulation portion 2j while having the CLC furnace 12 as the basic structure. The distribution pipes 15 are arranged at intervals in the horizontal direction, extend in the plate thickness direction of the partition wall 2c, and penetrate the guide wall 2m. The lower end of the guide wall 2 m is connected to the hearth 2d. The first flow path 2k is formed so as to pass between adjacent distribution pipes 15. The second flow path 2l is formed so as to pass through the inside of the distribution pipe 15. As a result, in the CLC furnace 42, the first flow path 2k and the second flow path 2l are partitioned from each other.

Therefore, in the CLC furnace 42, the first flow path 2k and the second flow path 2l can be physically separated, and the flow beds 2f flowing through the first flow path 2k and the second flow path 2l are mixed with each other to form the oxidation chamber 2a. It is possible to satisfactorily prevent the oxygen carrier particles moving from the side to the reduction chamber 2b side from being mixed with the oxygen carrier particles trying to move from the reduction chamber 2b side to the oxidation chamber 2a side.

Further, by partitioning the first flow path 2k and the second flow path 2l from each other, the flow velocities of the oxygen carrier particles flowing through the first flow path 2k and the second flow path 2l can be easily controlled individually. For example, by making the amount of the second supply gas supplied to the first flow path 2k and the second flow path 2l different, the flow velocity of the oxygen carrier particles flowing through the first flow path 2k and the flow velocity of the second flow path 2l are circulated. The flow velocity of the oxygen carrier particles can be made different. As an example, the flow velocity of the oxygen carrier particles flowing through the first flow path 2k can be set to be higher than the flow velocity of the oxygen carrier particles flowing through the second flow path 2l, but the flow rate is not limited to this. As a result, the degree of freedom in designing the circulation of the fluidized bed 2f in the CLC furnace 42 can be increased.

(Modified example of the third embodiment)
FIG. 6 is a perspective view showing the internal structure of the CLC furnace 52 according to the modified example of the third embodiment. As shown in FIG. 6, the CLC furnace 52 has a separation wall 2r provided in the circulation portion 2j while having the CLC furnace 12 as a basic structure. The lower end of the guide wall 2 m is located above the hearth 2d. The separation wall 2r extends horizontally inside the circulation portion 2j, and one end thereof is connected to the lower end of the guide wall 2m. The lower end of the partition wall 2c is located above the upper surface of the separation wall 2r. As a result, the first flow path 2k and the second flow path 2l are positioned so that the first flow path 2k is located above the separation wall 2r and the second flow path 2l is located below the separation wall 2r. , Separated by a separation wall 2r. Therefore, in the CLC furnace 52, the first flow path 2k and the second flow path 2l are partitioned from each other as in the CLC furnace 42.

Although not shown, air diffusers are provided on the upper surface of the separation wall 2r and the upper surface of the hearth 2d below the separation wall 2r. A second supply gas is supplied to this air diffuser. A plurality of nozzles are formed on the side surface of the air diffuser. The second supply gas supplied to the air diffuser pipe is supplied to the circulation portion 2j from a plurality of nozzles of the air diffuser pipe. The same effect as that of the CLC furnace 42 can be expected in the CLC furnace 52 having such a configuration.

The present invention is not limited to each embodiment and each modification, and the configuration and method of the present invention can be changed, added, or deleted without departing from the spirit of the present invention. Each embodiment and each modification may be arbitrarily combined with each other, and for example, a partial configuration in one embodiment may be applied to any one of the embodiments or modifications. Further, as the fuel, a gas fuel or a liquid fuel may be used in combination with the solid fuel.

Further, in the above-described first to third embodiments and the modified examples of the first and second embodiments, the first flow path 2k and the first flow path 2k and the first flow path 2k and the second by the second supply gas ejected from the same nozzle 2e in the circulation portion 2j. Oxygen carrier particles are circulated through the two flow paths 2l, and the unburned carbon component in the reduction chamber 2b is prevented from entering the oxidation chamber 2a side. The second supply gas for circulating oxygen carrier particles in 2l and the second supply gas for preventing the unburned carbon component in the reduction chamber 2b from entering the oxidation chamber 2a side are separate nozzles. It may be ejected from 2e.

Further, a single reduction chamber 2b is arranged in the center of the inside of the CLC furnace, a single oxidation chamber 2a is arranged so as to surround the reduction chamber 2b, and a cylindrical guide wall 2m is arranged in the reduction chamber 2b. A cylindrical partition wall 2c may be arranged between the oxidation chamber 2a and the reduction chamber 2b. The guide wall 2m can be arranged, for example, so as to be partially supported by the hearth 2d. In this case, the vertical cross section of the CLC furnace is substantially the same as the structure of the CLC furnace 22 shown in FIG.

R2 1st supply path R3 2nd supply path R4 3rd supply path V3 Flow control valve 1,21 CLC system 2,12,22,32,42,52 CLC furnace 2a Oxidation chamber 2b Reduction chamber 2c Partition wall 2f Flow bed 2j Circulation part 2k 1st flow path 2l 2nd flow path 2q Bending part 7 Upper space in the oxidation chamber 8 Upper space in the reduction chamber

Claims (10)

An oxidation chamber, a reduction chamber adjacent to the oxidation chamber, a flow bed that reciprocates and flows between the lower part of the oxidation chamber and the lower part of the reduction chamber and contains oxygen carrier particles, and the oxidation chamber and the reduction chamber. A single partition wall that partitions the upper space of the oxidation chamber and the upper space of the reduction chamber and whose lower end is arranged in the flow bed is formed inside the circulation portion that circulates the oxygen carrier particles. Equipped with a furnace body
In the oxidation chamber, the oxygen carrier particles are mixed with the oxygen carrier particles while flowing the oxygen carrier particles with the oxidizing first supply gas supplied from the outside, and the oxygen carriers are mixed with the oxygen carrier particles with the first supply gas. Oxidize the particles,
In the reduction chamber, the oxygen carrier particles oxidized in the oxidation chamber are mixed with the solid fuel while flowing by the second supply gas supplied from the outside and non-oxidizing, and oxidized in the oxidation chamber. The solid fuel is burned by the oxygen carrier particles, and the oxygen carrier particles oxidized in the oxidation chamber are reduced.
The circulation portion is provided by a first flow path for circulating the oxygen carrier particles oxidized in the oxidation chamber to the reduction chamber by a second supply gas supplied from the outside, and a second supply gas supplied from the outside. An internal circulation type chemical looping combustion furnace having a second flow path for circulating the oxygen carrier particles reduced in the reduction chamber to the oxidation chamber. The circulation portion is arranged adjacent to the oxidation chamber and in the reduction chamber.
The chemical looping combustion furnace according to claim 1, wherein the second supply gas is supplied into the circulation portion from the lower side to the upper side of the fluidized bed. The oxygen carrier particles oxidized in the oxidation chamber are supplied to the reduction chamber from above the fluidized bed in the reduction chamber by the second supply gas through the first flow path.
The chemical looping combustion furnace according to claim 1 or 2, wherein the solid fuel is supplied from the bottom of the fluidized bed into the reduction chamber. The first flow path extends in the vertical direction inside the fluidized bed, and the oxygen carrier particles oxidized in the oxidation chamber are directed by the second supply gas from the lower side to the upper side of the fluidized bed. The chemical looping combustion furnace according to claim 3, which circulates in a fluidized bed. The oxygen carrier particles reduced in the reduction chamber are supplied to the fluidized bed in the oxidation chamber by the second supply gas through the second flow path, and the first supply gas is supplied from below the oxidation chamber. The chemical looping combustion furnace according to any one of claims 1 to 4, which is supplied to the oxidation chamber. The second flow path is formed in the horizontal direction below the first flow path, and the oxygen carrier particles reduced in the reduction chamber are horizontally formed from the fluidized bed in the reduction chamber by the second supply gas. The chemical looping combustion furnace according to claim 5, which flows through the second flow path in the direction. The second flow path according to any one of claims 1 to 6, wherein the second flow path has a bent portion that extends upward and then bends downward from the reduction chamber side toward the oxidation chamber side. Chemical looping combustion furnace. The chemical looping combustion furnace according to any one of claims 1 to 7, wherein the first flow path and the second flow path are partitioned from each other. Any one of claims 1 to 8, wherein the first supply gas is air or oxygen-enriched air, and the second supply gas is water vapor or carbon dioxide gas, or a mixture of water vapor and carbon dioxide gas. The chemical looping combustion furnace described in. The chemical looping combustion furnace according to any one of claims 1 to 9,
A first supply path for supplying the first supply gas to the oxidation chamber and
A second supply path for supplying the second supply gas to the reduction chamber and
A third supply path for supplying the second supply gas into the circulation section,
The flow rate of the first supply gas flowing through the first supply path and the flow rate of the second supply gas flowing through the third supply path are independent of the flow rate of the second supply gas flowing through the second supply path. A chemical looping combustion system with an adjustable flow control valve.

Images