WO2013124999A1

WO2013124999A1 - Heat transport apparatus, and heat transport method

Info

Publication number: WO2013124999A1
Application number: PCT/JP2012/054353
Authority: WO
Inventors: 茂広茶圓; 川口　淳一郎; 宏人羽生; 理嗣曽根
Original assignee: 昭和電工株式会社
Priority date: 2012-02-23
Filing date: 2012-02-23
Publication date: 2013-08-29
Also published as: JP5891293B2; JPWO2013124999A1

Abstract

Provided are a heat transport apparatus and a heat transport method with which nitrous oxide can be used as an environmentally friendly energy source. A fuel gas including nitrous oxide (N₂O) is supplied to a decomposition reactor (22) having disposed therein a catalyst (21) for decomposing nitrous oxide, and the catalyst (21) is used to decompose the nitrous oxide included in the fuel gas. Steam is generated by a decomposition-gas boiler by way of heat recovery from decomposition gas (N₂, O₂) generated by decomposing nitrous oxide, the steam generated by the decomposition-gas boiler is used to drive the rotation of a steam turbine to obtain motive power, and the motive power is subsequently used to drive a heat pump to transport heat. Alternatively, the decomposition gas (N₂, O₂) generated by decomposing nitrous oxide is used to drive the rotation of a decomposition-gas turbine to obtain motive power, and the motive power is subsequently used to drive the heat pump to transport heat.

Description

Heat transport device and heat transport method

The present invention relates to a heat transport apparatus and a heat transport method using energy generated by decomposition of nitrous oxide (also referred to as N ₂ O, dinitrogen monoxide).

In recent years, with the growing awareness of the global environment, such as environmental destruction and resource depletion, there has been a shift from a society that relies on fossil fuels such as oil, coal, and natural gas to one that uses natural energy and renewable alternative energy. It has been demanded.

On the other hand, the use of nuclear energy, which has been advantageous from the viewpoints of environmental problems and energy security, has been urged to review its safety aspects due to radioactive waste disposal problems and the occurrence of nuclear accidents.

Therefore, the emergence of new energy friendly to the global environment in place of conventional fossil fuels and nuclear energy is desired in response to serious energy problems and environmental problems.

Japanese Patent Laid-Open No. 5-4027 Japanese Patent Laying-Open No. 2005-230795 JP 2006-181570 A Japanese Patent No. 4232820

Amid growing interest in the above-mentioned environmentally friendly energy, heating (including heating, hot water supply, hot water, drying, etc.) and cooling (including cooling, refrigeration, freezing, cold water, ice making, etc.), dehumidification, and humidification Even in the field of refrigeration and air conditioning that uses various heat sources such as these, the use of energy in place of conventional fossil fuels is required.

In such a situation, the present inventors propose use of nitrous oxide as energy friendly to the global environment by using energy generated by decomposition of nitrous oxide.

Nitrous oxide is chemically stable and easy to handle, and is approved as a food additive (Ministry of Health, Labor and Welfare No. 34, March 22, 2005). It is also used as a combustion aid.

On the other hand, nitrous oxide is considered to be one of the causes of global warming as a greenhouse gas having a warming effect about 310 times that of carbon dioxide (CO ₂ ). For this reason, in recent years, in order to prevent the release of nitrous oxide into the atmosphere, many technologies have been developed to decompose and remove nitrous oxide in exhaust gas discharged from, for example, factories, incineration facilities, and automobiles using catalysts. (For example, see Patent Documents 1 to 3.)

In addition, Patent Documents 1 and 2 disclose a technique in which heat generated during decomposition of nitrous oxide in the production process of adipic acid is used for preheating nitrous oxide. On the other hand, in Patent Document 3 described above, in an apparatus for decomposing nitrous oxide contained in excess anesthetic gas, heat exchange is performed between a gas introduced into the decomposition apparatus and a gas discharged from the decomposition apparatus. Discloses a technique for increasing energy efficiency by reducing heating energy and cooling energy.

However, these techniques are all aimed at decomposing and removing nitrous oxide released into the atmosphere. In addition, regarding the use of heat generated during decomposition of nitrous oxide, although heating (preheating) of nitrous oxide before decomposition is disclosed, suboxidation as an alternative energy alternative proposed by the present inventors is disclosed. There is no disclosure or suggestion about the use of nitrogen.

On the other hand, the present inventors have already developed a thruster device that generates thrust by using a cracked gas obtained by catalytically decomposing nitrous oxide (see Patent Document 4). As described in Patent Document 4, when nitrous oxide is decomposed using a catalyst for decomposing nitrous oxide, additional nitrous oxide may be self-decomposed (thermal decomposition) by the heat of decomposition. Is possible.

Based on such knowledge, the present inventors have found that the use of nitrous oxide as the above-mentioned environmentally friendly energy is possible by utilizing the energy generated by the decomposition of nitrous oxide. As a result of intensive studies, the present invention has been completed.

That is, an object of the present invention is to enable the use of nitrous oxide as energy friendly to the global environment, and a heat transport device and heat that enable heat transport using energy generated by decomposition of the nitrous oxide. It is to provide a transportation method.

The present invention provides the following means.
(1) a cracked gas boiler that generates steam by recovering heat from cracked gas generated by the decomposition of nitrous oxide;
A steam turbine that is rotationally driven by steam generated in the cracked gas boiler;
A heat transport device comprising: a heat pump that transports heat by driving the steam turbine.
(2) a cracked gas turbine that is rotationally driven by cracked gas generated by the decomposition of nitrous oxide;
A heat transport device comprising: a heat pump that transports heat by driving the cracked gas turbine.
(3) The cracking gas boiler or cracking gas turbine supplies a cracking reaction section in which a nitrous oxide decomposition catalyst for cracking the nitrous oxide is disposed, and a fuel gas containing nitrous oxide to the cracking reaction section. Fuel gas supply means,
In the decomposition reaction section, after decomposing nitrous oxide contained in the fuel gas using the nitrous oxide decomposing catalyst, the fuel supplied thereafter by the decomposition heat generated by the decomposition of the nitrous oxide The heat transport device according to (1) or (2) above, wherein the decomposition of nitrous oxide in the gas is continued.
(4) The cracked gas boiler or cracked gas turbine includes a flow rate adjusting means for adjusting a flow rate of the fuel gas supplied to the cracking reaction unit,
The heat transport device according to (3), wherein the temperature of the cracked gas is controlled by adjusting the flow rate of the fuel gas supplied to the cracking reaction section.
(5) The cracked gas boiler or cracked gas turbine includes a concentration adjusting unit that adjusts the concentration of nitrous oxide contained in the fuel gas,
The heat transport device according to (3) or (4) above, wherein the temperature of the cracked gas is controlled by adjusting the concentration of nitrous oxide contained in the fuel gas.
(6) The heat transport according to (5) above, wherein the concentration adjusting means adjusts the concentration of nitrous oxide contained in the fuel gas by adding nitrogen to the fuel gas. apparatus.
(7) The cracked gas boiler or cracked gas turbine includes temperature measuring means for measuring the temperature of the nitrous oxide cracking catalyst or cracked gas,
The flow rate adjustment by the flow rate adjustment unit or the concentration adjustment by the concentration adjustment unit is performed based on the measurement result by the temperature measurement unit, or any one of the items (4) to (6), Heat transport equipment.
(8) The cracked gas boiler or cracked gas turbine includes a preheating means for preheating the nitrous oxide decomposition catalyst,
The heat transport device according to any one of (3) to (7), wherein the nitrous oxide decomposition catalyst is preheated before the decomposition of the nitrous oxide is started.
(9) The cracked gas boiler or cracked gas turbine includes a nitrogen gas supply means for supplying nitrogen gas to the cracking reaction section,
9. The heat transport device according to any one of the above items (3) to (8), wherein nitrogen gas is supplied to the decomposition reaction unit after supply of fuel gas to the decomposition reaction unit is stopped.
(10) The heat pump heats the refrigerant while condensing a refrigerant circulating system in which the refrigerant circulates, a compression unit that compresses and sends out the refrigerant in the refrigerant circulation system, and the refrigerant compressed in the compression unit. A condensing part to be discharged; an inflating part for expanding the refrigerant radiated by the condensing part; and an evaporating part for allowing the refrigerant to absorb heat while evaporating the refrigerant expanded in the inflating part. The heat transport device according to any one of the preceding items (1) to (9), characterized in that is driven by the steam turbine or cracked gas turbine.
(11) The heat transport device according to (10), wherein the heat pump includes switching means for switching a direction in which the refrigerant flows.

(12) generating steam with a cracked gas boiler by heat recovery from cracked gas generated by the decomposition of nitrous oxide;
Rotating the steam turbine with steam generated by the cracked gas boiler;
A heat transport method including a step of performing heat transport with a heat pump by driving the steam turbine.
(13) rotationally driving a cracked gas turbine with cracked gas generated by cracking of nitrous oxide;
A heat transport method comprising: performing heat transport with a heat pump by driving the cracked gas turbine.
(14) A fuel gas containing the nitrous oxide is supplied to a cracking reaction section in which a nitrous oxide decomposition catalyst for decomposing the nitrous oxide is disposed, and is contained in the fuel gas in the cracking reaction section. After decomposing nitrous oxide using the nitrous oxide decomposition catalyst, the decomposition heat generated by the decomposition of nitrous oxide is used to continue the decomposition of nitrous oxide in the fuel gas supplied thereafter. The heat transport method according to item (12) or (13), which is characterized in that
(15) The heat transport method according to (14), wherein the decomposition of the nitrous oxide is continuously performed by controlling the temperature of the cracked gas.
(16) The heat transport method according to (15), wherein the temperature of the cracked gas is controlled by adjusting the flow rate of the fuel gas.
(17) The heat transport method as described in (15) or (16) above, wherein the temperature of the cracked gas is controlled by adjusting the concentration of nitrous oxide contained in the fuel gas.
(18) The heat transport method according to (17), wherein the concentration of nitrous oxide contained in the fuel gas is adjusted by adding nitrogen to the fuel gas.
(19) The heat according to any one of (15) to (18) above, wherein the temperature of the nitrous oxide decomposition catalyst or cracked gas is measured, and the temperature of the cracked gas is controlled based on the measurement result. Transport method.
(20) The heat transport method according to any one of (14) to (19) above, wherein the nitrous oxide decomposition catalyst is preheated before the decomposition of the nitrous oxide is started.
(21) The heat described in any one of (14) to (20) above, wherein nitrogen gas is supplied to the decomposition reaction section after supply of fuel gas to the decomposition reaction section is stopped. Transport method.

As described above, according to the present invention, it is possible to use nitrous oxide as energy friendly to the global environment, and it is possible to transport heat using the energy generated by the decomposition of nitrous oxide.

It is a schematic system diagram which shows the structure of the heat transport apparatus provided with the cracked gas boiler to which this invention is applied. It is a schematic system diagram which shows the structure of the heat transport apparatus provided with the cracked gas turbine to which this invention is applied. It is a schematic block diagram which shows the characterizing part of this invention with which the cracked gas boiler shown in FIG. 1 and the cracked gas turbine shown in FIG. 2 are provided. It is a flowchart which shows an example of the specific operation | movement (control method) in the characteristic part of this invention. It is process drawing of the heat transport method using the heat transport apparatus shown in FIG. It is process drawing of the heat transport method using the heat transport apparatus shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a heat pump with which the air-conditioner to which this invention is applied, (a) is a schematic system diagram which shows the state at the time of cooling, (b) is a schematic system diagram which shows the state at the time of heating. In embodiments, a graph showing the relationship between heating temperature and the N _{2 O} decomposition rate in the linear velocity and reactor nitrous oxide gas.

Hereinafter, a heat transport apparatus and a heat transport method to which the present invention is applied will be described in detail with reference to the drawings.

A heat transport apparatus and a heat transport method to which the present invention is applied use substituting energy generated by the decomposition of nitrous oxide (N ₂ O, also referred to as dinitrogen monoxide) as sub-environment-friendly energy. Nitrogen oxide can be used.

Nitrous oxide is a stable gas at normal temperature and atmospheric pressure. On the other hand, when the temperature is about 500 ° C. or higher, self-decomposition (thermal decomposition) occurs while generating heat. Thus, decomposition of nitrous oxide is accompanied by exotherm (exothermic reaction). And since the decomposition gas of the nitrous oxide heated up by the temperature rise (heat of decomposition) accompanying this decomposition becomes about 1600 degreeC, it can be said that nitrous oxide is a substance with built-in high energy.

Further, when nitrous oxide is decomposed using a catalyst, the decomposition start temperature can be lowered to, for example, about 350 to 400 ° C. And after decomposition | disassembly of nitrous oxide, it is possible to carry out decomposition | disassembly of the nitrous oxide supplied after that with the decomposition | disassembly heat generated by decomposition | disassembly of this nitrous oxide. Further, the nitrous oxide decomposed using the catalyst becomes a mixed gas (decomposed gas) of nitrogen (N ₂ ) and oxygen (O ₂ ) while generating heat.

Based on such knowledge, the present inventors have found that the use of nitrous oxide as the above-mentioned environmentally friendly energy is possible by utilizing the energy generated by the decomposition of nitrous oxide. As a result of further earnest research, the present invention has been completed.

Hereinafter, a heat transport apparatus shown in FIGS. 1 and 2 and a heat transport method using the heat transport apparatus will be described as embodiments of the present invention.
FIG. 1 is a schematic system diagram showing a configuration of a heat transport device including a cracked gas boiler 1 to which the present invention is applied. This heat transport device performs heat transport using the heat of decomposition generated by the decomposition of nitrous oxide (N ₂ O).

Specifically, the heat transport device shown in FIG. 1 includes a cracked gas boiler 1 that generates steam by heat recovery from cracked gas (N ₂ , O ₂ ) generated by the decomposition of nitrous oxide, and a cracked gas boiler 1. The steam turbine 2 that is rotationally driven by the steam generated in step 1, the compression heat pump 80 that transports heat by driving the steam turbine 2, the condenser 4 that cools and condenses the steam from the steam turbine 2, A water supply pump 5 for supplying the condensate from the condenser 4 to the cracked gas boiler 1 is schematically provided.

Further, the cracked gas boiler 1 to which the present invention is applied includes a steam generating section 7 that generates steam by heat exchange between a cracking reaction section 6 that decomposes nitrous oxide and a cracked gas obtained by cracking nitrous oxide. And.

On the other hand, FIG. 2 is a schematic system diagram showing a configuration of a heat transport device including the cracked gas turbine 11 to which the present invention is applied. This heat transport device performs heat transport using a decomposition gas (N ₂ , O ₂ ) generated by decomposition of nitrous oxide (N ₂ O).

Specifically, the heat transport apparatus shown in FIG. 2 includes a cracked gas turbine 11 that is rotationally driven by cracked gas generated by the decomposition of nitrous oxide, and a compression heat pump that transports heat by driving the cracked gas turbine 11. 80.

Further, the cracked gas turbine 11 to which the present invention is applied includes a cracking reaction section 13 for cracking nitrous oxide and a cracked gas obtained by cracking nitrous oxide from a nozzle (static blade) to a turbine blade (moving blade). And a turbine section 14 for obtaining power by rotating the turbine shaft.

The cracked gas boiler 1 and the cracked gas turbine 11 shown in FIGS. 1 and 2 include the cracking

reaction sections

6 and 13 for cracking nitrous oxide described above as a characteristic part of the present invention. That is, these

decomposition reaction units

6 and 13 are combustion gas boilers that generate steam using combustion heat generated when conventional fossil fuels or the like are burned, and combustion when conventional fossil fuels or the like are burned. It replaces a combustor (combustion reaction unit) provided in a combustion gas turbine that is rotationally driven using gas.

Specifically, for example, as shown in FIG. 3, the characteristic part of the present invention is a decomposition reactor (the above-mentioned decomposition) in which a nitrous oxide decomposition catalyst (hereinafter simply referred to as a catalyst) 21 for decomposing nitrous oxide is disposed. Corresponding to the reaction units 6 and 13) 22, a fuel gas supply line (fuel gas supply means) 23 for supplying a fuel gas containing nitrous oxide (N ₂ O) to the cracking reactor 22, and a cracking reactor 22 A nitrogen gas supply line (nitrogen gas supply means) 24 for supplying nitrogen gas (N ₂ ) to the reactor, a flow rate adjusting unit (flow rate adjusting means) 25 for adjusting the flow rate of the fuel gas supplied to the decomposition reactor 22, and a catalyst A temperature measuring device (temperature measuring means) 26 that measures the temperature of 21 and a control unit (control means) 27 that controls each part are provided.

The decomposition reactor 22 includes a main body (decomposition reaction chamber) 22a containing the catalyst 21 inside, a gas inlet 22b through which fuel gas is introduced into one end side of the main body 22a, and the main body 22a. It has a structure in which a gas discharge port 22c through which cracked gas is discharged is provided on the other end side.

In addition, it is preferable to use a material having excellent heat resistance and oxidation resistance as the material of the decomposition reactor 22, and in particular, a member on the side of the gas discharge port 22 c exposed to high temperature and high pressure by the decomposition gas has a high temperature. It is preferable to use a material that can sufficiently withstand thermal fatigue or oxidation under high pressure. Examples of such materials include stainless steel, Ni-base alloy, and Co-base alloy. Moreover, ceramics, silicon carbide (SiC), or the like can be used as a heat shielding material. Further, these composite materials may be used. Moreover, the decomposition reactor 22 may be provided with a mechanism for forcibly cooling by water cooling or air cooling.

As the catalyst 21, it is preferable to use a catalyst that can efficiently decompose nitrous oxide in a wide temperature range (particularly in a low temperature range) and can sufficiently withstand thermal fatigue, oxidation, and the like at high temperatures. Examples of such a catalyst having high decomposition efficiency of nitrous oxide and excellent heat resistance and oxidation resistance are disclosed in, for example, “JP 2002-153734 A” and “JP 2002-253967 A” described later. Things can be used.

Specifically, any of the catalysts shown in the following [1] to [6] can be used.
[1] A catalyst in which aluminum (Al), magnesium (Mg), and rhodium (Rh) are supported on a carrier.
[2] A catalyst in which magnesium (Mg) and rhodium (Rh) are supported on an alumina (Al ₂ O ₃ ) support.
[3] A catalyst in which rhodium (Rh) is supported on a carrier in which a spinel crystalline composite oxide is formed of at least a part of aluminum (Al) and magnesium (Mg).
[4] At least one metal selected from the group consisting of zinc (Zn), iron (Fe), manganese (Mn) and nickel (Ni), aluminum (Al) and rhodium (Rh) is supported on the carrier. catalyst.
[5] At least one metal selected from the group consisting of zinc (Zn), iron (Fe), manganese (Mn) and nickel (Ni) and rhodium (Rh) are supported on an alumina (Al ₂ O ₃ ) support. Catalyst.
[6] A spinel crystalline composite comprising at least a part of aluminum (Al) and at least one metal selected from the group consisting of zinc (Zn), iron (Fe), manganese (Mn), and nickel (Ni) A catalyst in which rhodium (Rh) is supported on a support on which an oxide is formed.

In the present invention, the support selected from silica (SiO ₂ ) and silica alumina (SiO ₂ —Al ₂ O ₃ ) is at least selected from the group consisting of rhodium (Rh), ruthenium (Ru), and palladium (Pd). A catalyst or the like carrying one noble metal can be suitably used. By using such a catalyst 21, it is possible to decompose nitrous oxide into nitrogen and oxygen with a decomposition efficiency close to 100%. In particular, when a catalyst having rhodium (Rh) supported on a support made of silica (SiO ₂ ) or silica alumina (SiO ₂ —Al ₂ O ₃ ) is used, nitrogen monoxide (NO) or nitrogen dioxide (NO _2). ) hardly occurs of the NO _x gases, such as, it is possible to decompose almost completely nitrogen and oxygen nitrous oxide.

Further, the catalyst 21 is a cordierite and metal honeycomb or porous ceramic carrier coated with alumina and impregnated with rhodium effective for decomposing nitrogen oxides by 2 to 3% by mass, Examples thereof include those in which a support layer made of alumina is formed on a honeycomb structure made of alumina, cordierite, or silicon carbide, and rhodium that is effective in decomposing nitrogen oxides is supported on the support layer. However, it is not necessarily limited to these.

In addition, as the other catalyst 21, for example, a catalyst used for decomposing and removing nitrous oxide in exhaust gas discharged in a manufacturing process of adipic acid, a manufacturing process of nitric acid, or the like can be used. Such a catalyst is represented by, for example, MAl ₂ O ₃ (M is any one of Pd, Cu, Cu / Mg, Cu / Zn, Cu / Zn / Mg), and M is 10 to 30. Examples thereof include a support in which a precious metal is supported at a rate of 0.1 to 2% by mass on an alumina support containing at a rate of mass%.

The shape of the catalyst 21 is not particularly limited. For example, any shape such as powder, granule, pellet, honeycomb, porous, pulverized, mesh, plate, or sheet can be used. What is necessary is just to select and use the optimal shape and size suitably from shapes.

The filling method of the main body 22a of the catalyst 21 and the shape of the main body 22a according to the catalyst 21 are also matched to the design of the cracking

reaction sections

6 and 13 included in the cracking gas boiler 1 and the cracking gas turbine 11. And can be implemented arbitrarily.

The decomposition reactor 22 may be configured to be able to replace the catalyst 21 (in some cases, the main body 22a) in accordance with the deterioration of the catalyst 21 over time. In addition, it is possible to extract and purify a noble metal component from the catalyst 21 whose performance has been reduced and recover it, and then use the recovered noble metal on a new carrier as a regenerated catalyst.

The decomposition reactor 22 is provided with a heater (preheating means) 28 for heating the catalyst 21. The heater 28 preheats (preheats) the catalyst 21 to a temperature at which nitrous oxide can be decomposed (decomposition start temperature) before starting decomposition of nitrous oxide, that is, before supplying fuel gas to the decomposition reactor 22. ).

For example, the heater 28 shown in FIG. 3 is disposed inside the main body portion 22a so as to be in contact with the periphery of the catalyst 21. The heater 28 is connected to a power source (not shown) via a power supply line 29, and can generate heat by supplying power from the power source. In addition, as the heater 28, a resistance heating method, an induction heating method, or the like can be used.

The heating method of the catalyst 21 is not limited to the method of heating the catalyst 21 with the heater 28 arranged inside the main body 22a, and the catalyst 21 is heated with the heater 28 arranged outside the main body 22a. It is also possible to use a method of heating. In this case, the main body 22a is heated by the heater 28, and the catalyst 21 can be heated by radiation or heat conduction from the main body 22a.

Further, as a method for heating the catalyst 21, it is also possible to use a method for heating the catalyst 21 by directly supplying electric power to the catalyst 21. In addition, the method for heating the catalyst 21 is not particularly limited, and can be appropriately selected from the methods for heating the catalyst 21.

The fuel gas supply line 23 is a pipe (flow path) whose one end is connected to the inlet side (gas inlet 22 b) of the cracking reactor 22 via the flow rate adjusting unit 25, and the other end side is a fuel gas A fuel gas supply source 31 is connected via the on-off valve 30.

The fuel gas on-off valve 30 is for opening / closing the fuel gas supply line 23 and for supplying / cutting off the fuel gas from the fuel gas supply source 31 (open / close means). In addition, the fuel gas on / off valve 30 can be used not only for opening and closing the fuel gas supply line 23 but also for adjusting the opening degree (including pressure and the like).

Furthermore, the fuel gas on-off valve 30 can be a control valve with a flow rate control (flow rate control valve) that can control the flow rate. The fuel gas on / off valve 30 is electrically connected to the control unit 27, and the control of the fuel gas on / off valve 30 can be controlled by the control unit 27.

The fuel gas on / off valve 30 is not limited to the configuration using the above-described control valve with flow rate adjustment (flow rate adjustment valve), but separately from the valve (open / close valve) for opening and closing the fuel gas supply line 23. A configuration in which a regulator (flow rate regulator) for adjusting the flow rate of the fuel gas flowing in the gas supply line 23 is also possible.

The fuel gas supply source 31 has a fuel gas storage part in which the fuel gas is temporarily stored in order to supply fuel gas containing nitrous oxide, and the fuel gas storage part is filled with nitrous oxide. A gas container (for example, a cylinder, a tank, a cardle, etc.) 31a is arranged. The fuel gas supply source 31 can supply the fuel gas containing nitrous oxide from the high-pressure gas container 31a to the fuel gas supply line 23 by opening the fuel gas on-off valve 30. .

The nitrogen gas supply line 24 is a pipe (flow path) whose one end side is connected to the upstream side of the flow rate adjustment unit 25 of the fuel gas supply line 23, and the nitrogen gas opening / closing valve 32 is connected to the other end side. A nitrogen gas supply source 33 is connected. The nitrogen gas supply line 24 has a function as a concentration adjusting means for adjusting the concentration of nitrous oxide contained in the fuel gas by introducing the nitrogen gas into the fuel gas supply line 23.

The nitrogen gas opening / closing valve 32 is for opening / closing the nitrogen gas supply line 24 and for supplying / blocking the nitrogen gas from the nitrogen gas supply source 33 (opening / closing means). In addition, the nitrogen gas on / off valve 32 can be used not only for opening and closing the nitrogen gas supply line 24 but also for adjusting the opening degree (including pressure and the like).

Furthermore, in order to adjust the supply amount of nitrogen gas supplied to the fuel gas supply line 23, a control valve with a flow rate adjustment (flow rate adjustment valve) capable of controlling the flow rate is used for the nitrogen gas on-off valve 32. preferable. The nitrogen gas on / off valve 32 is electrically connected to the control unit 27, and the control unit 27 can drive and control the nitrogen gas on / off valve 32.

The nitrogen gas on / off valve 32 is not limited to the configuration using the above-described control valve with a flow rate adjustment (flow rate adjustment valve), but separately from the valve (open / close valve) for opening and closing the nitrogen gas supply line 24. A configuration in which a regulator (flow rate regulator) for adjusting the flow rate of the nitrogen gas flowing in the gas supply line 24 is also possible.

The nitrogen gas supply source 33 has a nitrogen gas storage part in which nitrogen gas is temporarily stored, and the nitrogen gas storage part has a high-pressure gas container (for example, a cylinder, a tank, a curdle, etc.) 33a filled with nitrogen. Is arranged. The nitrogen gas supply source 33 can supply the nitrogen gas from the high-pressure gas container 33 a to the nitrogen gas supply line 24 by opening the nitrogen gas on-off valve 32.

The flow rate adjusting unit 25 may be anything that can adjust the flow rate (introduction amount) of the fuel gas introduced from the fuel gas supply line 23 into the decomposition reactor 22. A control valve (flow rate adjusting valve) or the like can be used. The flow rate adjusting unit 25 is electrically connected to the control unit 27, and the control unit 27 can drive and control the flow rate adjusting unit 25.

In the flow rate adjusting unit 25, a flow meter (flow rate measuring means) for measuring the flow rate of the fuel gas flowing in the flow rate adjusting unit 25 is provided, or a regulator or a control valve with such a flow meter is used. Thus, the flow rate of the fuel gas introduced into the decomposition reactor 22 can be adjusted with high accuracy.

The temperature measuring device 26 measures the temperature of the catalyst 21 directly or indirectly, is electrically connected to the control unit 27, and outputs a measurement result (measurement data) to the control unit 27.

For example, the temperature measuring device 26 shown in FIG. 3 is attached to the main body portion 22 a of the decomposition reactor 22, and can measure the temperature on the downstream side of the catalyst 21 while contacting the catalyst 21.

In the decomposition of nitrous oxide using the catalyst 21, since the nitrous oxide is decomposed while the nitrous oxide passes through the catalyst 21, the temperature on the upstream side (gas inlet 22b) side of the catalyst 21 is generally used. The temperature on the downstream (gas discharge port 22c) side becomes higher than that. Therefore, the catalyst 21 exposed to the high temperature and high pressure by the cracked gas, the deterioration of the members on the gas outlet 22c side (for example, thermal fatigue, oxidation, etc.), especially nitrous oxide contains oxygen in the cracked gas. It is preferable to measure the temperature on the downstream side (gas exhaust port 22c) side of the catalyst 21 described above in order to prevent the reaction (oxidation).

On the other hand, the temperature measuring device 26 is not limited to the configuration shown in FIG. 3 described above, and may be configured to measure the temperature on the upstream side (gas inlet 22b) side of the catalyst 21. This is preferable in detecting whether or not the catalyst 21 heated by the heater 28 has been heated to the decomposition start temperature before starting the decomposition of nitrous oxide. Then, based on the measurement result by the temperature measuring device 26, when the catalyst 21 is heated to the decomposition start temperature, the heating by the heater 28 may be stopped. Thereby, the heating by the heater 28 can be performed efficiently.

In addition, about the location which measures the temperature of the catalyst 21, it is not necessarily limited to said location, For example, in order to measure the average temperature of the catalyst 21, the temperature of the center part of the catalyst 21 is measured. It is also possible to measure the temperatures at these multiple locations separately.

In addition, the temperature measuring device 26 is not limited to the configuration that directly measures the temperature of the catalyst 21, and may indirectly measure the temperature of the catalyst 21 by measuring the temperature of the main body 22 a that houses the catalyst 21, for example. Is possible.

Further, the temperature measuring device 26 is not limited to the configuration for directly or indirectly measuring the temperature of the catalyst 21 described above, but directly or indirectly determines the temperature of the cracked gas discharged from the gas discharge port 22c of the cracking reactor 22. It is good also as a structure to measure to. Furthermore, it is good also as a structure which measures the temperature of both these catalysts 21 and cracked gas.

As the temperature measuring device 26, for example, a thermometer using a thermocouple, a non-contact type thermometer such as a radiation thermometer, a data logger, or the like can be used, but it is not necessarily limited to these. Instead, the catalyst 21 and the cracked gas can be appropriately selected from those that can be measured and used.

The control unit 27 is composed of a computer (CPU) or the like, and based on the measurement result (measurement data) from the temperature measuring device 26, according to the control program recorded therein, the flow rate adjusting unit 25 and the fuel gas on-off valve 30 described above. Control of the nitrogen gas on-off valve 32 is performed.

Specifically, in order to continuously perform the decomposition of nitrous oxide using the catalyst 21 in the decomposition reactor 22, it is important to control the temperature of the decomposition gas.

That is, if the temperature of the cracked gas becomes too high, as described above, the catalyst 21 exposed to the high temperature and high pressure by the cracked gas, the members on the gas discharge port 22c side, etc. may be deteriorated (for example, thermal fatigue or oxidation). There is. On the other hand, if the temperature of the cracked gas becomes too low, it may be difficult to continue the self-decomposition of nitrous oxide. Also, or is discharged from the gas discharge ports 22c of the decomposition reactor 22 without nitrous oxide is decomposed, optionally, NO _x gases described above or occur. These gases cause the above-mentioned global warming and air pollution.

Therefore, the control unit 27 can control the temperature of the cracked gas within a range in which the decomposition of the nitrous oxide using the catalyst 21 is continued in the cracking reactor 22 so that such a problem does not occur. preferable.

Here, as a method of controlling the temperature of the cracked gas, (1) a method of adjusting the flow rate of the fuel gas supplied to the cracking reactor 22, and (2) the concentration of nitrous oxide contained in the fuel gas. And a method of adjustment.

Among these, in the method using the above (1), the control unit 27 controls the flow rate adjusting unit 25 based on the measurement result from the temperature measuring device 26, and the fuel gas supply line 23 supplies the decomposition reactor 22. The flow rate of the supplied fuel gas is adjusted.

Specifically, when increasing the temperature of the cracked gas, control is performed to relatively increase the flow rate of the fuel gas supplied from the fuel gas supply line 23 to the cracking reactor 22. As a result, the amount of fuel gas introduced into the cracking reactor 22 is increased, and the temperature of the cracked gas is relatively increased by increasing the amount of decomposition (heat of decomposition) of nitrous oxide decomposed in the cracking reactor 22. It is possible.

On the other hand, when lowering the temperature of the cracked gas, control is performed to relatively lower the flow rate of the fuel gas supplied to the cracking reactor 22. As a result, the amount of fuel gas introduced into the cracking reactor 22 is reduced, and the temperature of the cracked gas is relatively lowered by reducing the amount of decomposition of nitrous oxide (heat of decomposition) decomposed in the cracking reactor 22. It is possible.

As described above, in the characteristic part of the present invention shown in FIG. 3, the decomposition of nitrous oxide using the catalyst 21 is continued in the decomposition reactor 22 while the temperature of the decomposition gas is controlled by the control unit 27. Can be performed automatically.

On the other hand, in the method using the above (2), the control unit 27 controls the nitrogen gas on-off valve 32 based on the measurement result from the temperature measuring device 26 and the nitrogen gas supply line 24 to the fuel gas supply line. The flow rate of the nitrogen gas supplied to 23 is adjusted.

Specifically, when increasing the temperature of the cracked gas, control is performed to relatively increase the concentration of nitrous oxide contained in the fuel gas. That is, a control for relatively reducing the flow rate of nitrogen gas supplied from the nitrogen gas supply line 24 to the fuel gas supply line 23 or stopping supply of nitrogen gas from the nitrogen gas supply line 24 to the fuel gas supply line 23. I do. Thereby, the addition of nitrogen gas to the fuel gas flowing in the fuel gas supply line 23 is stopped or the amount added is reduced, and the concentration of nitrous oxide contained in the fuel gas can be relatively increased. it can. As the amount of decomposition (heat of decomposition) of nitrous oxide decomposed in the decomposition reactor 22 increases accordingly, the temperature of the decomposition gas can be relatively increased.

On the other hand, when lowering the temperature of the cracked gas, control is performed to relatively lower the concentration of nitrous oxide contained in the fuel gas. That is, a control for relatively increasing the flow rate of nitrogen gas supplied from the nitrogen gas supply line 24 to the fuel gas supply line 23 or starting supply of nitrogen gas from the nitrogen gas supply line 24 to the fuel gas supply line 23. I do. Accordingly, the concentration of nitrous oxide is increased while adding or increasing the amount of nitrogen gas to the fuel gas flowing in the fuel gas supply line 23 and diluting the nitrous oxide contained in the fuel gas with the nitrogen gas. Can be made relatively low. As a result, the decomposition amount (heat of decomposition) of nitrous oxide decomposed in the decomposition reactor 22 decreases, so that the temperature of the decomposition gas can be relatively lowered.

In the method using the above (2), in addition to the nitrogen gas described above, an inert gas such as helium (He), neon (Ne), argon (Ar), xenon (Xe), krypton (Kr), etc. Alternatively, the concentration of nitrous oxide contained in the fuel gas can be adjusted by adding air (including dry air) or the like to the fuel gas.

As described above, in the characteristic part of the present invention shown in FIG. 3, nitrous oxide is continuously decomposed using the catalyst 21 in the decomposition reactor 22 while controlling the temperature of the decomposition gas. Is possible.

In addition, in the characteristic part of the present invention shown in FIG. 3, the above-described temperature control of the cracked gas can be performed by combining the methods using (1) and (2). In the method using the above (1) and (2), the above-described temperature control of the cracked gas can be stably performed with a simple configuration. On the other hand, in this invention, it is not necessarily limited to the method using said (1), (2), You may perform temperature control of cracked gas using the method of other than that.

Further, in the present invention may be provided with NO _x meter for measuring the concentration of NO _x in the decomposition gas (NO _x measurement means). In this case, by measuring the concentration of NO _x gas such as undecomposed nitrous oxide (N ₂ O), nitric oxide (NO), nitrogen dioxide (NO ₂ ), etc. contained in the cracked gas, It is possible to accurately control the temperature of the cracked gas.

Furthermore, in the present invention, it is possible to provide means for removing NO _x contained in the cracked gas (NO _x removing means). The NO _x removal unit, for example, by adding ammonia (NH ₃₎ decomposition gas containing NO _x, and selective reaction (reduction) is not ammonia and NO _x by denitration catalyst, water (H ₂ A denitration apparatus that decomposes into O) and nitrogen (N ₂ ) can be used. As the denitration catalyst, an optimum one may be selected from conventionally known ones. Further, as the NO _x removal means, a NO _x decomposition catalyst capable of directly decomposing NO _x contained in the cracked gas may be used.

Further, when the decomposition of nitrous oxide using the catalyst 21 is stopped in the cracking reactor 22, the supply of fuel gas to the cracking reactor 22 is stopped, and then nitrogen gas is supplied to the cracking reactor 22. Is preferably supplied.

This is because immediately after the supply of the fuel gas to the cracking reactor 22 is stopped, the cracked gas stays in the catalyst 21, and the catalyst 21 may be deteriorated by oxygen contained in the cracked gas. Because.

In this case, the control unit 27 performs control to close the fuel gas on-off valve 30, thereby stopping the supply of the fuel gas to the decomposition reactor 22, and the nitrogen gas supplied from the nitrogen gas supply line 24. Is introduced into the decomposition reactor 22.

Thereby, the nitrogen gas introduced into the cracking reactor 22 pushes out the cracked gas retained in the catalyst 21, and the cracked gas retained in the catalyst 21 can be removed. The control unit 27 introduces nitrogen gas into the cracking reactor 22 for a certain period of time, that is, a sufficient time to remove the cracked gas remaining in the catalyst 21, and then closes the nitrogen gas on-off valve 32. And the supply of nitrogen gas to the decomposition reactor 22 is stopped.

Thereby, deterioration of the catalyst 21 due to oxygen can be prevented, and the life of the catalyst 21 can be extended. Further, it is possible to reduce the frequency of replacing the above-described catalyst 21 (extend the replacement cycle). Furthermore, when this method is used, it is possible to easily resume the decomposition of nitrous oxide after temporarily stopping the decomposition of nitrous oxide.

When the above-described decomposition of nitrous oxide is stopped, in addition to the nitrogen gas, for example, inert gases such as He, Ne, Xe, Ar, Kr, air (including dry air), and the like are decomposed. It is also possible to introduce into the reactor 22.

Here, an example of a specific operation (control method) in the characteristic part of the present invention will be described with reference to the flowchart shown in FIG.
In the characterizing portion of the present invention, first, in step S101, the heater 28 is driven and the catalyst 21 is heated (preheated) before starting the decomposition of nitrous oxide.

Next, in step S102, based on the temperature of the catalyst 21 measured by the temperature measuring device 26, the control unit 27 determines whether or not the catalyst 21 has been heated to the decomposition start temperature. If it is determined that the catalyst 21 has been heated to the decomposition start temperature, the process proceeds to step S103, and the driving of the heater 28 is stopped in step S103. On the other hand, when it is determined that the catalyst 21 has not been heated to the decomposition start temperature, the heating of the catalyst 21 by the heater 28 is continued until the catalyst 21 reaches the decomposition start temperature.

Next, in step S104, fuel gas is supplied to the decomposition reactor 22, and the decomposition reactor 22 decomposes nitrous oxide using the catalyst 21. Note that the flow rate of the fuel gas supplied to the decomposition reactor 22, the concentration of nitrous oxide contained in the fuel gas, and the like are set in advance.

Next, in step S105, based on the temperature of the catalyst 21 (or cracked gas) measured by the temperature measuring device 26, the control unit 27 sets a value (range) in which the temperature of the catalyst 21 (or cracked gas) is set in advance. It is determined whether or not the number is exceeded. If it is determined that the temperature of the catalyst 21 (or cracked gas) has exceeded the set value (range), the process proceeds to step S106. On the other hand, if it is determined that the temperature of the catalyst 21 (or cracked gas) is within the set value (range), the process proceeds to step S110.

Next, in step S106, the control unit 27 determines (comparison) whether the temperature of the catalyst 21 (or cracked gas) is higher or lower than a set value (range).

When it is determined that the temperature of the catalyst 21 (or cracked gas) is higher than the set value (range), the process proceeds to step S107, and the controller 27 is supplied to the cracking reactor 22 in step S107. The fuel gas flow rate or the concentration of nitrous oxide contained in the fuel gas is adjusted to decrease. Then, after the adjustment, the process proceeds to step S109.

On the other hand, when it is determined that the temperature of the catalyst 21 (or cracked gas) is lower than the set value (range), the process proceeds to step S108, and the controller 27 is supplied to the cracking reactor 22 in step S108. The adjustment is made to increase the flow rate of the fuel gas or the concentration of nitrous oxide contained in the fuel gas. Then, after the adjustment, the process proceeds to step S109.

In the adjustment in step S107 or step S108, for example, a range in which the set value of the flow rate of the fuel gas supplied to the cracking reactor 22 or the set value of the concentration of nitrous oxide contained in the fuel gas can be adjusted. Then, it is divided into a predetermined number of steps, and the set value is lowered or increased by one step from the current step.

Next, in step S109, based on the temperature of the catalyst 21 (or cracked gas) measured by the temperature measuring device 26, the control unit 27 determines whether the temperature of the catalyst 21 (or cracked gas) has returned to the set value (range). Determine whether or not. When it is determined that the temperature of the catalyst 21 (or cracked gas) has returned to the set value (range), the process proceeds to step S110.

On the other hand, if the temperature of the catalyst 21 (or cracked gas) does not return to the set value (range), the process returns to step S106, and the temperature of the catalyst 21 (or cracked gas) is again higher or lower than the set value (range). After the determination (comparison), the process proceeds to step S107 or S108, and the set value of the flow rate of the fuel gas supplied to the decomposition reactor 22 or the concentration of nitrous oxide contained in the fuel gas is determined. Adjust the setting value further down or up one step. Then, the process proceeds to step S109, where it is determined whether or not the temperature of the catalyst 21 (or cracked gas) has returned to the set value (range), and until the temperature of the catalyst 21 (or cracked gas) returns to the set value (range). Repeat such adjustments. Further, as a result of repeating such adjustment, if the adjustable range is exceeded, the control unit 27 determines that it is abnormal and forcibly proceeds to step S110 (not shown in FIG. 4).

Next, in step S110, the control unit 27 determines whether or not to stop the fuel gas supply. Examples of the case of stopping the supply of the fuel gas include a case where a stop command is received from the outside and a case where it is determined that there is an abnormality in step S109. And when stopping supply of fuel gas, it progresses to Step S111. On the other hand, when the supply of the fuel gas is not stopped, the process returns to step S105, and the temperature measurement of the catalyst 21 (or cracked gas) by the temperature measuring device 26 is continued.

Next, in step S111, after the supply of fuel gas is stopped, the process proceeds to step S112, and in this step S112, nitrogen gas is supplied to the decomposition reactor 22. Thereby, the cracked gas which nitrogen gas stayed in the catalyst 21 is pushed out, and the cracked gas stayed in the catalyst 21 can be removed.

In the present invention, the measurement data measured by the temperature measuring device 26 and the determination result of the control unit 27 based on the measurement data may be displayed on a monitor (not shown) or output to a printer, for example. Moreover, not only the automatic control by the control part 27 mentioned above but you may perform manual control by an operator etc., for example.

In addition, when it is determined that there is an abnormality in step S109, it may be notified as necessary. The notification method is not particularly limited, and for example, an alarm can be issued or a display can be performed.

The cracked gas boiler 1 shown in FIG. 1 and the cracked gas turbine 11 shown in FIG. 2 have the same configuration as the characteristic part of the present invention as described above, thereby controlling the temperature of the cracked gas described above, It is possible to continuously decompose nitrous oxide.

That is, in the cracked gas boiler 1 and the cracked gas turbine 11 having the characteristic portions of the present invention, a fuel gas containing nitrous oxide is supplied to the cracking

reaction units

6 and 13, and in the cracking

reaction units

6 and 13, fuel is supplied. After the nitrous oxide contained in the gas is decomposed using the catalyst 21, the decomposition heat generated by the decomposition of the nitrous oxide continuously decomposes the nitrous oxide in the fuel gas supplied thereafter. It can be done.

Next, the compression heat pump 80 provided in the heat transport apparatus shown in FIGS. 1 and 2 will be described.
The compression heat pump 80 includes a refrigerant circulation system 81 in which the refrigerant R circulates, a compression section 82 that compresses and sends out the refrigerant R in the refrigerant circulation system 81, and condenses the refrigerant R compressed by the compression section 82. , The condensing part 83 for releasing heat from the refrigerant R, the expansion part 84 for expanding the refrigerant R radiated by the condensing part 83, and the refrigerant R expanded by the expansion part 84 while evaporating the heat, And an evaporating unit 85 that absorbs water.

The refrigerant circulation system 81 includes a pipe (flow path) in which the compression unit 82, the condensing unit 83, the expansion unit 84, and the evaporation unit 85 are connected in order. The refrigerant R circulates in the refrigerant circulation system 81 while repeating heat absorption and heat release due to state change (vaporization / liquefaction) accompanying pressure change (compression / expansion) as a heat medium for transporting heat. . Examples of the refrigerant R include fluorocarbons (fluorocarbons) (hydrofluorocarbon (HFC), hydrochlorofluorocarbon (HCFC), etc.), carbon dioxide, ammonia, hydrocarbons (propane, butane, isobutane, etc.), water, and the like. Etc. can be used.

The compression unit 82 includes a compressor (compressor), and is driven by being connected to the steam turbine 2 or the cracked gas turbine 11 (turbine unit 14). The refrigerant R is sent out to the condensing unit 83 as a high-temperature and high-pressure gas while being heated by being compressed by the compression unit 82.

The condensing unit 83 includes a heat exchanger (heat radiator) called a condenser (condenser), and condenses the refrigerant R by heat exchange with the outside while the refrigerant R compressed by the compression unit 82 passes through the inside. However, heat is released from the refrigerant R. As a result, the refrigerant R is sent to the expansion section 84 as a normal temperature / high pressure liquid. Further, in the heat pump 80, by providing a fan (air blowing means) 86 to the condenser section 83 side, it is possible to efficiently release the hot air T _H to the outside. Further, the condensing section 83, it is also possible to perform the heating using the hot air T _H, it is possible to use a heat exchanger of the radiator (hot) side as a heater (heating means).

The expansion part 84 is composed of an expansion valve (expansion valve) or a capillary tube. The refrigerant R is expanded by the expansion unit 84 and is cooled to a low-temperature / low-pressure liquid, and is sent to the evaporation unit 85.

The evaporation unit 85 includes a heat exchanger (heat absorber) called an evaporator (evaporator), and evaporates the refrigerant R by heat exchange with the outside while the refrigerant R expanded by the expansion unit 84 passes through the inside. However, the refrigerant R absorbs heat. Thus, the refrigerant R is sent to the compression unit 82 as a low-temperature and low-pressure gas. Further, in the heat pump 80, it is possible to efficiently discharge the cold air _TL to the outside by providing the fan (blower unit) 87 on the evaporation unit 85 side. Further, the evaporator 85 can perform cooling using the cold air _TL , and the heat exchanger (low temperature) side heat exchanger can be used as a cooler (cooling means).

As described above, the compression heat pump 80 can perform heat transport while circulating the refrigerant R in the refrigerant circulation system 81 using the steam turbine 2 or the cracked gas turbine 11 as a power source. .

As shown in FIG. 5, the heat transport method to which the present invention is applied includes step S1-1 in which steam is generated in the cracked gas boiler 1 by heat recovery from cracked gas generated by decomposition of nitrous oxide, and a cracked gas boiler. 1, the steam turbine 2 is rotationally driven by the steam generated in 1, and the heat transport is performed by the compression heat pump 80 by driving the steam turbine 2.

Specifically, in the cracked gas boiler 1 shown in FIG. 1, a high-temperature and high-pressure cracked gas obtained by cracking nitrous oxide is supplied from the cracking reaction section 6 to the steam generating section 7. Thereby, in the said steam generation part 7, it is possible to generate a vapor | steam by heat exchange with cracked gas.

Furthermore, in the heat transport device including the cracked gas boiler 1, the steam turbine 2 is rotationally driven by the steam generated by the cracked gas boiler 1 (steam generating unit 7). Then, heat transport can be performed by the compression heat pump 80 by driving the steam turbine 2.

Then, the steam discharged from the steam turbine 2 is cooled by the condenser 4 and condensed, and then supplied to the cracked gas boiler 1 by the feed water pump 5, and again heated by the cracked gas boiler 1 with the cracked gas. It will circulate as steam by exchange.

In the cracked gas boiler 1, the above-described characteristic portions of the present invention are not necessarily limited to the configuration shown in FIG. That is, when the characteristic part of the present invention shown in FIG. 3 is applied to the cracked gas boiler 1, it can be appropriately changed according to the type and size of the boiler.

For example, the shape, number, arrangement, etc. of the decomposition reactor 22 can be appropriately changed according to the design of the decomposition gas boiler 1. Further, the fuel gas supply line 23 and the nitrogen gas supply line 24 connected to the decomposition reactor 22, the flow rate adjusting unit 25, the temperature measuring device 26, the control unit 27, the heater 28, the power supply line 29, and the fuel gas on / off valve 30. The fuel gas supply source 31, the nitrogen gas on / off valve 32, the nitrogen gas supply source 33, etc. can be appropriately changed according to the design of the cracked gas boiler 1.

On the other hand, the cracked gas boiler 1 can have the same structure as that of an existing combustion gas boiler, etc., except for the above-described features of the present invention. For example, the structure of the cracked gas boiler 1 to which the present invention is applied other than the characteristic portions of the present invention may be of the same type as a conventional round boiler or water tube boiler. In addition, about a round boiler, a furnace tube boiler, a smoke tube boiler, a furnace tube fire tube boiler, a standing boiler etc. can be mentioned, for example. On the other hand, examples of the water pipe boiler include a natural circulation type, a forced circulation type, and a once-through type.

The cracked gas boiler 1 is configured to supply cracked gas from the cracking reaction section 6 to the steam generating section 7 and generate steam by heat exchange with the cracked gas in the steam generating section 7. However, it is not necessarily limited to such a configuration. For example, in the present invention, the decomposition reaction unit 6 and the steam generation unit 7 are configured integrally, and steam is generated by exchanging heat between the decomposition reaction unit 6 and the steam generation unit 7. It is also possible.

Specifically, the steam generation unit 7 is provided outside the decomposition reaction unit 6 (decomposition reactor 22), and steam is generated by heat exchange with heat (decomposition heat) generated in the decomposition reaction unit 6. It can be configured. In this case, it is possible to obtain steam by the heat generated in the decomposition reaction unit 6 at the same time that the decomposition reaction unit 6 (decomposition reactor 22) is cooled.

In addition to the configuration shown in FIG. 1, the cracked gas boiler 1 includes, for example, a superheater that further heats the steam obtained in the steam generation unit 7 to form superheated steam, and the cracking reaction unit 6. It is possible to have a configuration equipped with auxiliary equipment (equipment / parts) such as a preheater that preheats fuel gas, feed water, etc. with the obtained high-temperature cracked gas, and other necessary safety equipment (equipment / parts). is there.

Further, in the heat transport device shown in FIG. 1, the configuration other than the cracked gas boiler 1, that is, the steam turbine 2, the condenser 4, the feed water pump 5, and the like described above are the same as the existing ones. It is possible to use. Further, the same applies to ancillary equipment (equipment / parts) and security equipment (equipment / parts).

As described above, in the heat transport apparatus and the heat transport method including the cracked gas boiler 1 to which the present invention is applied, heat transport using energy generated by the decomposition of nitrous oxide is possible. And according to this invention, the cracked gas boiler 1 which enabled utilization of nitrous oxide as energy friendly to a global environment, the heat transport apparatus provided with such a cracked gas boiler 1, and such a heat transport apparatus It is possible to provide a heat transport method using

As shown in FIG. 6, another heat transport method to which the present invention is applied includes step S2-1 for rotationally driving the cracked gas turbine 11 with cracked gas generated by the decomposition of nitrous oxide, Step S2-2 in which heat transport is performed by the compression heat pump 80.

Specifically, in the cracked gas turbine 11 shown in FIG. 2, a high-temperature and high-pressure cracked gas obtained by cracking nitrous oxide is supplied from the cracking reaction section 13 to the turbine section 14. Thereby, in the turbine part 14, it is possible to spray cracked gas from the nozzle (stationary blade) to the turbine blade (moving blade), thereby rotating the turbine shaft to obtain power.

Furthermore, in the heat transport device including the cracked gas turbine 11, it is possible to transport heat with the compression heat pump 80 by driving the cracked gas turbine 11 (turbine unit 14).

In the cracked gas turbine 11, the above-described characteristic portions of the present invention are not limited to the configuration shown in FIG. That is, when the characteristic part of the present invention shown in FIG. 3 is applied to the cracked gas turbine 11, it is possible to make appropriate changes in accordance with the type and size of the turbine.

For example, the shape, number, arrangement, etc. of the cracking reactor 22 can be appropriately changed according to the design of the cracking gas turbine 11. Further, the fuel gas supply line 23 and the nitrogen gas supply line 24 connected to the decomposition reactor 22, the flow rate adjusting unit 25, the temperature measuring device 26, the control unit 27, the heater 28, the power supply line 29, and the fuel gas on / off valve 30. The fuel gas supply source 31, the nitrogen gas on-off valve 32, the nitrogen gas supply source 33, etc. can be appropriately changed according to the design of the cracked gas turbine 11.

On the other hand, in the cracked gas turbine 11, the structure other than the above-described features of the present invention has a configuration in which an existing combustion gas turbine includes a compressor that compresses combustion air and sends it to a combustor. On the other hand, such a configuration is unnecessary. Thereby, the decomposition gas turbine 11 can have a simple configuration and can be reduced in weight.

On the other hand, the cracked gas turbine 11 may include a compressor (supercharger) connected to a turbine shaft (not shown). A fuel gas containing nitrous oxide compressed (supercharged) by the compressor (supercharger) may be supplied to the decomposition reaction unit 13. When the fuel gas is compressed (supercharged) and used, it is preferably compressed (supercharged) within a range where nitrous oxide is not liquefied.

In addition to the configuration shown in FIG. 2, the cracked gas turbine 11 includes, for example, auxiliary equipment (equipment / parts) such as a preheater that preheats fuel gas with the high-temperature cracked gas obtained in the cracking reaction section 13. ), And other necessary security equipment (equipment / parts).

As described above, in the heat transport device and the heat transport method to which the present invention is applied, heat transport using energy generated by decomposition of nitrous oxide is possible. And according to this invention, it is possible to provide the heat transport apparatus which enabled utilization of nitrous oxide as energy friendly to a global environment, and the heat transport method using such a heat transport apparatus.

It should be noted that the present invention is not necessarily limited to the configuration of the heat transport device shown in FIGS. 1 and 2, and various modifications and the like can be added without departing from the spirit of the present invention.

For example, the heat transport device shown in FIG. 1 and FIG. 2 includes a compression heat pump 80A as shown in FIG. 7 instead of the compression heat pump 80, thereby performing cooling and heating. Can be configured.

7A shows the state of the heat pump 80A during cooling, and FIG. 7B shows the state of the heat pump 80A during heating. Further, in the heat pump 80A shown in FIGS. 7A and 7B, the description of the same parts as the heat pump 80 is omitted and the same reference numerals are given in the drawings.

Specifically, the compression heat pump 80A includes, in addition to the configuration of the heat pump 80, a four-way valve (switching means) 88 that switches a direction in which the refrigerant R in the refrigerant circulation system 81 flows, and a room installed indoors. Machine 89 and an outdoor unit 90 installed outdoors.

Here, in the heat exchanger on the indoor unit 89 side and the heat exchanger on the outdoor unit 90 side, the functions of the condensing unit 83 and the evaporating unit 85 are changed by switching the flow direction of the refrigerant R by the four-way valve 88. Change. 7A, the heat exchanger on the indoor unit 89 side functions as the evaporator 85, and the heat exchanger on the outdoor unit 90 functions as the condenser 83. On the other hand, during the heating shown in FIG. 7B, the heat exchanger on the indoor unit 89 side functions as the condensing unit 83, and the heat exchanger on the outdoor unit 90 side functions as the evaporating unit 85.

In an air conditioner including the heat pump 80A as described above, the compression unit 82 is driven by the steam turbine 2 or the cracked gas turbine 11 (not shown in FIG. 7). Thereby, in the heat pump 80A, the refrigerant R performs heat transport while circulating in the refrigerant circulation system 81. 7A, the indoor unit 89 side fan 87 discharges cool air (cold air) _TL into the room, and during the heating shown in FIG. 7B, the indoor unit 89 side fan 87. Accordingly, it is possible to release the indoor warm air (the hot air) T _H.

Note that during the cooling shown in FIG. 7A, the hot air _TH is released to the outside by the fan 86 on the outdoor unit 90 side. On the other hand, during the heating shown in FIG. 7B, the cool air _TL is discharged to the outside by the fan 86 on the outdoor unit 90 side.

In addition to the cooling and heating described above, the air conditioner to which the present invention is applied can also have a dehumidifying function for dehumidifying the room. For this dehumidification, for example, by a cooling operation in which the air volume is reduced, moisture in the air is dewed with a heat exchanger on the indoor unit side to dehumidify, and then a weak cooling dehumidification (dry) method for returning the dried air to the room, There is a reheat dehumidification (heat recycling) method in which moisture in the air is dewed by dew condensation by a heat exchanger on the indoor unit side, and then dry and cool air is reheated by the reheater and then returned to the room.

Heat transport apparatus according to the present invention, it is possible to obtain a cold air (cold) T _L described above, a hot air (hot) T _H, and can be variously applied to refrigeration and air conditioning fields. For example, the heat transport device to which the present invention is applied can be applied to air conditioning equipment and air conditioning equipment such as the above-described cooling and heating air conditioners. In the heating field, in addition to heating, the present invention can be applied to heating equipment, heating equipment, and the like that perform hot water supply, hot water, drying, and the like. On the other hand, in the cooling field, in addition to cooling, it can be applied to cooling equipment and cooling equipment for performing refrigeration, freezing, cold water, ice making, and the like.

Further, the heat transport apparatus to which the present invention is applied can be applied to a variety of sizes from large to small. In addition to its use for factories (industrial) and homes (households), it can be used in various fields, and it can be designed to suit the application, such as installation (stationary), portable, and portable. do it.

Nitrous oxide used in the present invention can be produced industrially. Specifically, examples of the method for industrially producing nitrous oxide include methods using the following (1) to (3).

(1) Ammonia direct oxidation method
2NH ₃ + 2O ₂ → N ₂ O + 3H ₂ O

(2) Ammonium nitrate pyrolysis method
NH ₄ NO ₃ → N ₂ O + 2H ₂ O

(3) Sulfamic acid method
NH ₂ SO ₃ H + HNO ₃ → N ₂ O + H ₂ SO ₄ + H ₂ O

Regarding nitrous oxide produced industrially, for example, high purity nitrous oxide having a purity of 99.9 (3N) to 99.999 (5N)%, purity of 97.0% or more (Japan Pharmacopoeia) Examples thereof include medical nitrous oxide and industrial nitrous oxide having a purity of 98% or more.

In addition, examples of the method for producing nitrous oxide include the following methods (4) to (10).

(4) Urea decomposition method
2 (NH ₂ ) ₂ CO + 2HNO ₃ + H ₂ SO ₄ → 2N ₂ O + 2CO ₂ + (NH ₄ ) ₂ SO ₄ + 2H ₂ O

(5) Production method from hydroxylamine
4NO + 2NH ₂ OH → 3N ₂ O + 3H ₂ O
2NH ₂ OH + NO ₂ + NO → 2N ₂ O + 3H ₂ O
2NH ₂ OH + O ₂ → N ₂ O + 3H ₂ O

(6) By-product N ₂ O from organic reaction
Recovery of by-product N ₂ O from the production process of adipic acid.
Recovery of by-product N ₂ O from the production of glioxal.

(7) Reduction of nitrite or nitrite
A solution of nitrous acid or nitrite is reduced using warm sulfite, sodium, amalgam, stannous chloride or the like as a reducing agent.

(8) Reduction of nitric acid
Nitric acid is reduced with zinc or tin, or with sulfurous acid gas.

(9) Reduction of nitrate
2KNO ₃ + 6HCOOH → N ₂ O + 4CO ₂ + 5H ₂ O + 2HCOOK

(10) Dehydration of hyponitrous acid
H ₂ N ₂ O ₂ + H ₂ SO ₄ → H ₂ SO ₄ .H ₂ O + N ₂ O

Then, the produced nitrous oxide is filled in the high-pressure gas container 31a by a gas maker, then sent to the fuel gas supply source 31, and temporarily stored in the fuel gas storage section. On the other hand, the high-pressure gas container 31a can be used repeatedly by being returned to the gas manufacturer after use and being refilled.

The fuel gas supply method is not limited to the method of supplying using the high-pressure gas container 31a (replacement of the high-pressure gas container 31a). For example, the fuel gas supply is performed using a transportation means such as a tanker or a tank lorry. It is possible to use a method of supplying to a storage tank (high pressure gas container 31a) installed in the source 31. Furthermore, it is also possible to use a method of supplying fuel gas containing nitrous oxide to a storage tank (high pressure gas container 31a) installed in the fuel gas supply source 31 through a pipeline.

The nitrogen gas supply method is not limited to the method of supplying using the high-pressure gas container 33a (replacement of the high-pressure gas container 33a), and the method of supplying using the same method as the fuel gas supply method described above. It is possible.

In the present invention, the decomposition start temperature of nitrous oxide can be lowered by using the catalyst 21. After the decomposition of nitrous oxide, it is possible to continuously decompose the nitrous oxide supplied thereafter by the heat of decomposition generated by the decomposition of nitrous oxide.

Therefore, in the present invention, it is only necessary to preheat the catalyst 21 before starting the decomposition of nitrous oxide. After the decomposition of nitrous oxide, the heat of decomposition generated by the decomposition of nitrous oxide keeps the temperature of the catalyst 21 at or above the temperature necessary for decomposing nitrous oxide. Decomposition can be performed continuously.

Specifically, the temperature of the catalyst 21 is preferably in the range of 200 to 600 ° C. from the viewpoint of catalyst activity, and more preferably in the range of 350 to 450 ° C. from the viewpoint of ease of decomposition reaction. That is, in the present invention, it is preferable to perform preheating by the heater 28 and temperature control of the cracked gas by the control unit 27 so that the temperature of the catalyst 21 falls within such a range.

On the other hand, since nitrous oxide itself undergoes autolysis at about 500 ° C. or higher, nitrous oxide is continuously decomposed without using the catalyst 21 by keeping the decomposition reactor 22 at or above the autolysis temperature. It is also possible to However, it is known that when nitrous oxide is self-decomposed without using the catalyst 21, NO _x gas is generated as a decomposition byproduct. Therefore, in the present invention, it is preferable to use the catalyst 21 in order to prevent the generation of the NO _x gas. The catalyst 21 can be used even when the temperature is higher than the nitrous oxide autolysis temperature.

The temperature of the fuel gas may be any temperature at which nitrous oxide does not liquefy, and can usually be used at room temperature or lower. On the other hand, the fuel gas can be used by preheating to a temperature higher than room temperature. For example, when the concentration of nitrous oxide contained in the fuel gas is low, the decomposition of nitrous oxide can be promoted by preheating the fuel gas.

The concentration of nitrous oxide contained in the fuel gas is not particularly limited. For example, the nitrous oxide concentration adjusted in the range of 1 to 100%, or when more energy needs to be obtained, Those adjusted in the range of more than 50% to 100% and further adjusted in the range of more than 70% to 100% can be used. Further, by adjusting the concentration of nitrous oxide described above, it is possible to adjust the decomposition reaction rate of nitrous oxide and the like.

Moreover, in this invention, it is possible to utilize cracked gas as respiratory gas by adjusting the density | concentration of nitrous oxide mentioned above. Specifically, since about 80% of the volume of nitrogen is nitrogen (N ₂ ) and about 20% is oxygen (O ₂ ), for example, nitrous oxide (N ₂ O contained in the fuel gas) is used. ) And nitrogen (N ₂ ) in a volume ratio (molar ratio) of N ₂ O: N ₂ = 1: 1. That is, if nitrogen gas is added to the fuel gas and the concentration of nitrous oxide contained in the fuel gas is 50%, the nitrous oxide contained in the fuel gas is finally converted into nitrogen and oxygen. Since 1 mol of nitrous oxide is decomposed into 1 mol of nitrogen and 0.5 mol of oxygen when decomposed, the ratio of nitrogen (N ₂ ) and oxygen (O ₂ ) contained in this decomposition gas is The ratio (molar ratio) is N ₂ : O ₂ = 4: 1. Thereby, since the ratio of nitrogen (N ₂ ) and oxygen (O ₂ ) contained in the cracked gas can be brought close to the air composition, this cracked gas can be used as a breathing gas.

Specifically, when the cracked gas is used as a breathing gas, the oxygen concentration is preferably in the range of about 18 to 24%. In this case, the concentration of nitrous oxide contained in the fuel gas is 44. It is preferable to be in the range of about ~ 63%.

In the present invention, it is possible to use a nitrous oxide having a concentration of less than 44%, that is, a fuel gas having a low nitrous oxide concentration. In this case, although the energy (energy density) generated by the decomposition of the fuel gas is lowered, the decomposition reaction of the nitrous oxide contained in the fuel gas is made gentle so that the above-described decomposition gas increases the temperature and pressure. It is possible to suppress deterioration (for example, thermal fatigue, oxidation, etc.) of each member such as the exposed catalyst 21 and the decomposition reactor 22. That is, in the present invention, it is possible to adjust the concentration of nitrous oxide contained in the fuel gas in consideration of the heat resistance and oxidation resistance of the respective materials such as the catalyst 21 and the decomposition reactor 22 described above. .

On the other hand, in the present invention, it is possible to use a nitrous oxide having a concentration exceeding 63%, that is, a fuel gas having a high nitrous oxide concentration. In this case, the energy (energy density) generated by the decomposition of the fuel gas can be increased, and the output of the decomposition gas boiler 1 and the decomposition gas turbine 11 can be improved.

In particular, in the present invention, even when a nitrous oxide concentration of 100% is used, it is possible to continuously decompose nitrous oxide using the catalyst 21. In the present invention, not only high-purity (for example, purity 99.9 (3N) to 99.999 (5N)%) nitrous oxide but also the purity of the nitrous oxide is considered in consideration of the production cost of nitrous oxide. It is also possible to use nitrous oxide with a low (for example less than 97% purity).

The concentration adjustment of nitrous oxide by nitrogen gas described above is a method of adding nitrogen gas or the like to the fuel gas before decomposition of nitrous oxide, but nitrogen gas or the like is added to the decomposition gas after decomposition of nitrous oxide. The method of adding may be sufficient. Further, a fuel gas in which the concentration of nitrous oxide has been adjusted in advance may be used.

Regarding components other than nitrous oxide contained in the fuel gas, in addition to the nitrogen added for adjusting the concentration of nitrous oxide described above, unmixed components that were mixed during the production of nitrous oxide described later are used. Examples include reactants, by-products, air, and inevitable impurities.

In the present invention, an oxygen concentration meter (oxygen measuring means) for measuring the oxygen concentration in the cracked gas may be provided. In this case, it is possible to measure the concentration of oxygen contained in the cracked gas, and to accurately control the temperature of the cracked gas described above based on the measurement result.

The space velocity (Space Velocity) of the fuel gas introduced into the decomposition reactor 22 may be set to an optimum value according to the design, for example, in the range of 10 to 140,000 hr ⁻¹ , preferably It can be set in the range of 100 to 10,000 hr ⁻¹ .

In the present invention, the cracked gas can also be used for fuel combustion. As long as the fuel is combustible using oxygen contained in the cracked gas, for example, in addition to fossil fuels such as petroleum, coal, and natural gas, alternative fuels such as biomass fuel are used. can do. In addition, it is possible to appropriately select and use from gaseous fuel, liquid fuel, and solid fuel.

Hereinafter, the nitrous oxide decomposition catalyst described in “JP 2002-153734 A” will be described.
The concentration of nitrous oxide contained in exhaust gas discharged from factories and incineration facilities is 10% or less, while the concentration of nitrous oxide contained in excess anesthetic gas discharged from the operating room excludes excess anesthetic gas. Although it is somewhat diluted with compressed air in the apparatus, it is 70% or less, which is a very high concentration. The nitrous oxide decomposition catalyst of the present invention is a catalyst that can cope with the decomposition of nitrous oxide having a low concentration to a high concentration.

Further, the nitrous oxide decomposition catalyst of the present invention can be decomposed at a relatively low temperature, is less susceptible to activity degradation due to moisture even in the presence of moisture, and reduces the generation amount of NO _x below an allowable concentration. The amount of NO _x generated can be reduced to about 1/10 to 1/100 or less of the conventional cracking catalyst.

The nitrous oxide decomposition catalyst of the present invention comprises any one of the following catalysts [1] to [3] containing three kinds of metals, aluminum, magnesium and rhodium as essential components: [1] aluminum, magnesium and rhodium [2] a catalyst in which magnesium and rhodium are supported on an alumina carrier, [3] a carrier in which a spinel crystalline composite oxide is formed of at least a part of aluminum and magnesium. The following [4] containing, as essential components, a catalyst on which rhodium is supported, and at least one metal selected from the group consisting of two metals, aluminum and rhodium, and zinc, iron, manganese and nickel. ] To [6], [4] at least one selected from the group consisting of zinc, iron, manganese and nickel A catalyst in which aluminum and rhodium are supported on a carrier, [5] a catalyst in which rhodium is supported on an alumina carrier, at least one metal selected from the group consisting of zinc, iron, manganese and nickel, [6] Rhodium is supported on a carrier on which a spinel crystalline composite oxide is formed by at least a part of aluminum and at least one metal selected from the group consisting of zinc, iron, manganese, and nickel. At least one catalyst selected from catalysts can be used.

As the carrier used for the catalyst of [1], a carrier selected from the group consisting of alumina, silica, zirconia, ceria, titania and tin oxide can be used, and as the carrier used for the catalyst of [4], alumina A carrier selected from zirconia, ceria, titania and tin oxide can be used. Carriers having a surface area of about 30 to 300 m ² / g can be used, and there is no particular limitation on the shape, but depending on the reactor or reaction method, it is suitable for each of granular, powder, honeycomb, etc. You can choose the shape.

In the catalyst of [1], it is preferable that the aluminum and magnesium supported on the carrier contain aluminum in an atomic ratio of at least 2 with respect to magnesium. Magnesium is preferably contained in an amount of 0.1 to 20.0% by mass based on the metal atom.

Moreover, it is preferable that at least a part of aluminum forms a spinel-type crystalline composite oxide with magnesium, and the spinel-type crystalline composite oxide is formed, for example, by firing a carrier supporting aluminum and magnesium. be able to. The spinel structure is a structure found in an oxide having a chemical formula of XY ₂ O ₄ and belongs to a cubic system, and Al and Mg are known to form a MgAl ₂ O ₄ spinel structure. The reason for the nitrous oxide decomposition catalyst of the present invention is not clear, but at least a part of aluminum forms a spinel crystalline composite oxide with magnesium, thereby improving the resolution of nitrous oxide. It is considered that the effect of reducing the generation amount of NO _x is exhibited.

In the catalyst of [4], at least one metal selected from the group consisting of zinc, iron, manganese and nickel and aluminum supported on the carrier is selected from the group consisting of zinc, iron, manganese and nickel. It is preferable that at least 2 or more are contained by atomic ratio with respect to at least 1 type of metal. In addition, it is preferable that at least one metal selected from the group consisting of zinc, iron, manganese and nickel is contained in an amount of 0.1 to 40.0% by mass in terms of metal atoms.

Moreover, it is preferable that at least a part of aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group consisting of zinc, iron, manganese, and nickel. The spinel crystalline composite oxide can be produced by firing a carrier supporting aluminum and at least one metal selected from the group consisting of zinc, iron, manganese and nickel. Aluminum, zinc, iron, manganese and nickel are known to form a spinel structure of MAl ₂ O ₄ (M = Zn, Fe, Mn, Ni). The reason for the nitrous oxide decomposition catalyst of the present invention is not clear, but at least a part of aluminum is at least one metal selected from the group consisting of zinc, iron, manganese and nickel, and a spinel crystalline composite. that forms the oxides, thereby improving the resolution of nitrous oxide, is believed to exert an effect of reducing the amount of generation of NO _x.

The carrier used for the catalyst of [2] is alumina, and the alumina is not particularly limited, but those having a surface area of about 50 to 300 m ² / g can be used. The magnesium supported on the alumina preferably contains aluminum in an atomic ratio of at least 2 with respect to magnesium. Magnesium is preferably contained in an amount of 0.1 to 20.0% by mass in terms of metal atoms. Moreover, it is preferable that at least a part of aluminum forms a spinel crystalline composite oxide with magnesium.

The carrier used for the catalyst of [5] is alumina, and the alumina is not particularly limited, but those having a surface area of about 50 to 300 m ² / g can be used. At least one metal selected from the group consisting of zinc, iron, manganese and nickel supported on alumina is an atomic ratio of aluminum to at least one metal selected from the group consisting of zinc, iron, manganese and nickel. It is preferable that at least two or more are included. It is preferable that at least one metal selected from the group consisting of zinc, iron, manganese and nickel is contained in an amount of 0.1 to 40.0% by mass based on the metal atom. Moreover, it is preferable that at least a part of aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group consisting of zinc, iron, manganese, and nickel.

[3] A catalyst in which a spinel-type crystalline composite oxide is formed of at least a part of aluminum and magnesium is used as the catalyst [3]. The atomic ratio of aluminum and magnesium in the catalyst of [3] is preferably such that aluminum is contained in an atomic ratio of at least 2 with respect to magnesium. Magnesium is preferably contained in an amount of 0.1 to 20.0% by mass based on the metal atom.

The catalyst [6] uses a carrier in which a spinel crystalline composite oxide is formed of at least a part of aluminum and at least one metal selected from the group consisting of zinc, iron, manganese and nickel. [6] The atomic ratio of aluminum and at least one metal selected from the group consisting of zinc, iron, manganese and nickel in the catalyst of [6] is at least 1 selected from the group where aluminum is zinc, iron, manganese and nickel It is preferable that at least 2 or more is contained by atomic ratio with respect to the metal of seed | species. In addition, it is preferable that at least one metal selected from the group consisting of zinc, iron, manganese and nickel is contained in an amount of 0.1 to 40.0% by mass in terms of metal atoms.

The rhodium contained in the nitrous oxide decomposition catalyst of the present invention is preferably 0.05 to 10% by mass in terms of metal atoms in any of the catalysts [1] to [6]. More preferably, the content is 0.1 to 6.0% by mass. Although it is possible to improve the catalyst activity at low temperature by increasing the amount of rhodium supported, it is not preferable to support 10% by mass or more in view of the cost of the catalyst, and 0.05% by mass or less. Sufficient nitrous oxide decomposition activity cannot be obtained.

Next, the method for producing the nitrous oxide decomposition catalyst of the present invention will be described.
Various production methods can be used for the nitrous oxide decomposition catalyst of the present invention. For example, (1) impregnation method, (2) coprecipitation method, (3) kneading method, and the like can be used. Hereinafter, taking these three production methods as examples, the production method of the nitrous oxide decomposition catalyst of the present invention will be described.

(1) Method for producing catalyst using impregnation method When the impregnation method is used, the above-mentioned catalysts [1] to [6] can be produced. When the catalyst of [1] is produced, an inorganic acid salt (nitrate, hydrochloride, sulfate, etc.) of aluminum and magnesium is first applied to a support selected from the group consisting of alumina, silica, zirconia, ceria, titania and tin oxide. ) Or organic acid salts (oxalate, acetate, etc.). In the case of producing the catalyst of [4], the support selected from the group consisting of alumina, zirconia, ceria, titania and tin oxide is firstly at least one selected from the group consisting of aluminum and zinc, iron, manganese and nickel. Impregnation with inorganic acid salts (nitrate, hydrochloride, sulfate, etc.) or organic acid salts (oxalate, acetate, etc.) of seed metals. In the production of the catalyst [2], an alumina carrier is impregnated with a magnesium inorganic acid salt (nitrate, hydrochloride, sulfate, etc.) or an organic acid salt (oxalate, acetate, etc.). When the catalyst of [5] is produced, an inorganic support (nitrate, hydrochloride, sulfate, etc.) or an organic salt of at least one metal selected from the group consisting of zinc, iron, manganese, and nickel is used on an alumina support. Impregnate with acid salts (oxalate, acetate, etc.). As the at least one metal salt selected from the group consisting of an aluminum salt, a magnesium salt and zinc, iron, manganese, and nickel, it is preferable to use a nitrate.

When the catalyst of [1] is produced, the amount supported on the carrier of aluminum and magnesium is preferably such that aluminum is supported so that the atomic ratio with respect to magnesium is 2 or more. It is preferable to make it 0.1 to 20.0% by mass. When the catalyst of [4] is produced, the amount of aluminum supported on at least one metal carrier selected from the group consisting of aluminum, zinc, iron, manganese and nickel is aluminum, zinc, iron, manganese and nickel. It is preferably supported so that the atomic ratio with respect to at least one metal selected from the group consisting of 2 or more is supported, and the supported amount of at least one metal selected from the group consisting of zinc, iron, manganese and nickel However, it is preferable to be 0.1 to 40.0% by mass of the total catalyst. In the production of the catalyst [2], it is preferable that magnesium is supported so that the atomic ratio to aluminum is ½ or less, and the amount of magnesium supported is 0.1-20. It is preferable to be 0% by mass. In addition, when producing the catalyst of [5], at least one metal selected from the group consisting of zinc, iron, manganese and nickel is supported so that the atomic ratio with respect to aluminum is ½ or less. In addition, it is preferable that the supported amount of at least one metal selected from the group consisting of zinc, iron, manganese and nickel is 0.1 to 40.0% by mass of the total catalyst.

After supporting the desired metal salt on the carrier, the carrier is dried and fired to contain, for example, aluminum and magnesium, and at least part of the aluminum forms a spinel-type crystalline composite oxide with magnesium. A carrier can be obtained, and this carrier is used as the carrier for the catalyst of [1]. Similarly, it contains aluminum and at least one metal selected from the group consisting of zinc, iron, manganese and nickel, and at least a part of aluminum is selected from the group consisting of zinc, iron, manganese and nickel. Thus, a support in which a spinel-type crystalline composite oxide is formed with at least one kind of metal can be obtained, and this support is used as a support for the catalyst of [4]. For example, the drying temperature after impregnating the aluminum salt and magnesium salt in the catalyst [1], the aluminum salt in the catalyst [4], and at least one metal salt selected from the group consisting of zinc, iron, manganese and nickel The drying temperature after impregnating is not particularly limited, but is preferably in the temperature range of 80 to 150 ° C, more preferably in the temperature range of 100 to 130 ° C. The drying atmosphere is not particularly limited, and nitrogen or air can be used. The drying time is not particularly limited, but when using the impregnation method, it may usually be about 2 to 4 hours.

Calcination of the carrier after impregnation and drying can be performed in a temperature range of 400 to 900 ° C., preferably 500 to 700 ° C. When the firing temperature is lower than 400 ° C., crystallization is not sufficient, and when it is 900 ° C. or higher, the specific surface area of the carrier is decreased, which is not preferable. The firing time is not particularly limited, but may be about 1 to 10 hours, preferably about 2 to 4 hours, and the firing temperature may be changed stepwise. Long-term firing is economically undesirable because the effect is saturated, and short-term firing may be less effective. Moreover, baking can be performed using a baking furnace, a muffle furnace, etc., and any of nitrogen or air may be used as a distribution gas at this time.

Next, a rhodium salt is supported on the carrier obtained by firing. As the rhodium salt, an inorganic acid salt (nitrate, hydrochloride, sulfate, etc.) or an organic acid salt (oxalate, acetate, etc.) can be used, and nitrate is preferably used. In the step of supporting the rhodium salt, for example, in the case of producing a catalyst containing three kinds of metals, aluminum, magnesium and rhodium, as essential components, at least a part of the aluminum obtained using the above method is magnesium and It is preferably performed on the carrier forming the spinel crystalline composite oxide, but it may be performed simultaneously with the step of impregnating and supporting aluminum and magnesium on the carrier or the step of impregnating and supporting magnesium on the alumina carrier. Further, the supported amount of rhodium is preferably 0.05 to 10% by mass of the whole catalyst.

Similarly, the step of supporting the rhodium salt is for producing a catalyst containing as essential components at least one metal selected from the group consisting of two metals, aluminum and rhodium, and zinc, iron, manganese and nickel. In the support, at least a part of the aluminum obtained by the above method is used as a carrier that forms a spinel crystalline composite oxide with at least one metal selected from the group consisting of zinc, iron, manganese, and nickel. Preferably, it is carried out with respect to the step of impregnating and supporting at least one metal selected from the group consisting of aluminum and zinc, iron, manganese and nickel on the support, or from zinc, iron, manganese and nickel on the alumina support. It may be performed simultaneously with the step of impregnating and supporting at least one metal selected from the group consisting of Further, the supported amount of rhodium is preferably 0.05 to 10% by mass of the whole catalyst. Here, if a support in which at least a part of aluminum forms a spinel crystalline composite oxide with magnesium is used in advance, the catalyst of [3] is produced by supporting a rhodium salt on the support in the same manner as described above. can do. In addition, if a support in which at least a part of aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group consisting of zinc, iron, manganese, and nickel is used, a rhodium salt is added to the support. The catalyst of [6] can be produced by supporting the catalyst.

Next, the rhodium-supported catalyst precursor is dried under the same drying conditions as described above, and the dried catalyst precursor is calcined. The firing temperature is preferably 200 to 500 ° C, more preferably 300 to 400 ° C. Although the catalyst obtained by calcination can be used as a nitrous oxide decomposition catalyst, it is preferable to further perform a reduction treatment, and a rhodium-containing catalyst with higher activity can be obtained by carrying out the reduction treatment. The reduction treatment can be performed by, for example, (1) a method of re-drying after hydrazine reduction and firing, or (2) a method of hydrogen reduction, and a method of hydrogen reduction is preferably used. When using the hydrogen reduction method, the reduction temperature is preferably 200 to 500 ° C., more preferably 300 to 400 ° C. Although the reduction time is not particularly limited, the treatment can be performed in about 1 to 10 hours, preferably about 2 to 4 hours. Moreover, you may perform a reduction process, without performing a baking process, and a rhodium containing catalyst with high activity can be obtained also in this case. As a method for producing a catalyst by carrying out a reduction treatment without performing a calcination treatment, a method in which hydrogen is reduced at a temperature of 200 to 500 ° C. is preferable.

(2) Method for Producing Catalyst Using Coprecipitation Method When the coprecipitation method is used, the above catalysts [3] and [6] can be produced. As a method for producing the catalyst of [3] using the coprecipitation method, for example, ammonia water is dropped into an aqueous solution containing aluminum and magnesium nitrate to neutralize and precipitate, and if necessary, left to age and washed with filtered water. Check that the water has been thoroughly washed with the conductivity of the washing water. Next, after drying for about 10 to 12 hours under the same conditions as in the impregnation method, the obtained dried body is pulverized and molded with uniform particle sizes. Further, a carrier in which at least a part of aluminum forms a spinel-type crystalline composite oxide with magnesium is obtained by baking in a nitrogen or air atmosphere under the same conditions as in the impregnation method.

The amount of aluminum and magnesium is preferably such that aluminum has an atomic ratio of 2 or more with respect to magnesium, and magnesium is preferably contained in an amount of 0.1 to 20.0% by mass of the total catalyst in terms of metal atoms. . At least a part of the aluminum thus obtained carries a rhodium salt on a carrier that forms a spinel-type crystalline composite oxide with magnesium. The method, the amount supported, and the subsequent treatment method are the same as the above impregnation method. Can be done.

Further, as a method for producing the catalyst of [6] using the coprecipitation method, for example, an aqueous solution containing an aluminum nitrate and at least one metal nitrate selected from the group consisting of zinc, iron, manganese and nickel is used. Aqueous ammonia is added dropwise to neutralize and precipitate, and if necessary, aged as it is, washed with filtered water, and it is confirmed that it has been sufficiently washed with the conductivity of the washing water. Next, after drying for about 10 to 12 hours under the same conditions as in the impregnation method, the obtained dried body is pulverized and molded with uniform particle sizes. Furthermore, by firing in a nitrogen or air atmosphere under the same conditions as the impregnation method, at least a part of aluminum is selected from the group consisting of zinc, iron, manganese and nickel and spinel crystallinity. A carrier forming a complex oxide is obtained.

The amount of at least one metal selected from the group consisting of aluminum and zinc, iron, manganese and nickel is an atomic ratio of aluminum to at least one metal selected from the group consisting of zinc, iron, manganese and nickel. Preferably, at least one metal selected from the group consisting of zinc, iron, manganese and nickel is contained in an amount of 0.1 to 40.0% by mass in terms of metal atoms. It is preferable. At least a portion of the aluminum thus obtained carries a rhodium salt on a carrier that forms a spinel crystalline composite oxide with at least one metal selected from the group consisting of zinc, iron, manganese and nickel. The method, the loading amount and the subsequent treatment method can be carried out in the same manner as the above impregnation method.

(3) Catalyst production method using a kneading method [3] and [6] catalysts can be produced using a kneading method. As a method for producing the catalyst of [3] using the kneading method, for example, water is added to alumina and / or aluminum hydroxide and magnesium oxide, magnesium hydroxide and / or magnesium salt, for example, if necessary, The mixture obtained by mechanical mixing can be dried, and further subjected to a firing treatment under the same conditions as in the impregnation method to obtain the spinel crystalline composite oxide. The amount of aluminum and magnesium is preferably such that aluminum has an atomic ratio of 2 or more with respect to magnesium, and magnesium is preferably contained in an amount of 0.1 to 20.0% by mass of the total catalyst in terms of metal atoms. .

At least a portion of the aluminum thus obtained carries a rhodium salt on a fired body that forms a spinel-type crystalline composite oxide with magnesium. The method, the amount supported, and the subsequent treatment method are the same as the above impregnation method. This method can be used. The rhodium salt may be added in advance when alumina or the like is mechanically mixed.

Examples of the method for producing the catalyst of [6] using the kneading method include at least one oxide selected from the group consisting of alumina and / or aluminum hydroxide and zinc, iron, manganese and nickel, and hydroxylation. For example, water is added to the product and / or metal salt, if necessary, and the mixture obtained by mechanical mixing is dried, and further subjected to a firing treatment under the same conditions as in the impregnation method. An oxide can be obtained. Further, the amount of at least one metal selected from the group consisting of aluminum and zinc, iron, manganese and nickel is such that aluminum is based on at least one metal selected from the group consisting of zinc, iron, manganese and nickel. The atomic ratio is preferably 2 or more, and at least one metal selected from the group consisting of zinc, iron, manganese and nickel is 0.1 to 40.0% by mass of the total catalyst in terms of metal atoms. It is preferably included.

At least a portion of the aluminum thus obtained carries a rhodium salt on a fired body that forms a spinel-type crystalline composite oxide with at least one metal selected from the group consisting of zinc, iron, manganese, and nickel. As the method, the loading amount and the subsequent treatment method, the same method as the above impregnation method can be used. The rhodium salt may be added in advance when alumina or the like is mechanically mixed.

Next, a method for decomposing nitrous oxide using the decomposition catalyst of the present invention will be described. When the decomposition reaction of nitrous oxide is performed using the decomposition catalyst of the present invention, it can be performed in a temperature range of 200 to 600 ° C. The decomposition catalyst of the present invention and nitrous oxide may be contacted in the gas phase, preferably in the temperature range of 300 to 500 ° C, more preferably in the temperature range of 350 to 450 ° C. If the temperature is lower than 200 ° C., decomposition of nitrous oxide is not sufficient, and if it is 600 ° C. or higher, the catalyst life tends to be short, which is not preferable. The catalyst bed system is not particularly limited, but a fixed bed is generally preferably used.

In addition, the catalytic activity of the conventional palladium catalyst decreases due to the influence of moisture and does not return to the original activity even when the moisture is removed, whereas the cracking catalyst of the present invention has 1 to 3% moisture coexistence. Although the activity may slightly decrease depending on the condition, it has a characteristic of returning to the original activity again when moisture is removed.

Next, the composition of the gas that can be decomposed using the decomposition catalyst of the present invention will be described. The concentration of nitrous oxide contained in exhaust gas discharged from factories and incineration facilities is 10% or less. By using the decomposition catalyst of the present invention, nitrous oxide having a concentration of 1 ppm to 10% contained in exhaust gas. Nitrogen can be decomposed. On the other hand, the concentration of nitrous oxide discharged from the operating room by the surplus anesthetic gas exclusion device may be as high as 3 to 70%. Further, when decomposing nitrous oxide contained in the anesthetic gas, the reaction usually involves 13 to 20% oxygen, and the reaction is performed under conditions that are severe for the decomposition catalyst. Therefore, if heat removal is possible and the temperature can be controlled sufficiently, the concentration of nitrous oxide to be decomposed is not particularly limited, but the reaction in which nitrous oxide decomposes into nitrogen and oxygen is an exothermic reaction. The concentration of nitric oxide is preferably 3 to 50%, preferably 3 to 25%, more preferably 3 to 10%.

Space velocity is the amount of gas supplied per unit catalyst (SV: Space Velocity) ^may be in the range of 10hr ^-1 ~ 20000hr -1, preferably in the range of ^100hr ^-1 ~ ^10000hr -1.

Hereinafter, the nitrous oxide decomposition catalyst described in “Japanese Patent Application Laid-Open No. 2002-253967” will be described.
The nitrous oxide decomposition catalyst of the present invention is a catalyst capable of decomposing a low concentration to a high concentration nitrous oxide. The concentration of nitrous oxide contained in the surplus anesthetic gas discharged from the operating room is 70% or less, although it is somewhat diluted with compressed air, and is very high. This can be achieved by using a decomposition catalyst for nitrogen oxides.

In addition, the nitrous oxide decomposition catalyst of the present invention can recover its activity by activating regeneration even when it is deteriorated by the volatile anesthetic contained in the excess anesthetic gas. Moreover at a relatively low temperature can decompose nitrous oxide, less subject to deactivation due to water even when water coexists, it is possible to suppress the generation amount of the NO _x to less than the allowable concentration, conventional cracking catalysts respect, it is possible to reduce the generation amount of the NO _x to about 1 / 10-1 / 100 following levels.

The nitrous oxide decomposition catalyst of the present invention contains at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium as an essential component, and is any one of the following (1) to (3) A catalyst can be used.
(1) A catalyst comprising (a) at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium on a carrier selected from silica or silica alumina.
(2) The silica support includes (a) at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium, (b) aluminum, and (c) at least one metal selected from the group consisting of zinc, iron and manganese. And a catalyst.
(3) (a) at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium, and (d) at least one metal selected from the group consisting of magnesium, zinc, iron and manganese on the silica alumina support. A supported catalyst.

The support used for the catalyst of (1) is silica or silica alumina, and these supports are not particularly limited, but those having a surface area of about 50 to 300 m ² / g can be used. There is no particular limitation on the shape, and a shape suitable for each of a granular shape, a powder shape, a honeycomb shape, and the like can be selected depending on the reactor or the reaction method.

The carrier used for the catalyst of (2) is silica and is not particularly limited, but those having a surface area of about 50 to 300 m ² / g can be used. Although there is no restriction | limiting in particular about a shape, A shape suitable for each, such as a granular form, a powder form, and a honeycomb form, can be selected with a reactor or reaction method.

Of the components supported on the silica support, at least one metal selected from the group (c) consisting of zinc, iron and manganese is preferably contained in an amount of 0.1 to 5.0% by mass of the total catalyst mass, more preferably Is preferably contained in an amount of 0.2 to 1.0% by mass. Even if the metal selected from the group (c) is contained in an amount of 5.0% by mass or more based on the total mass of the catalyst, the effect may be saturated.

The aluminum supported on the silica support is preferably contained in an atomic ratio of at least 2 to at least one metal selected from the group (c) consisting of zinc, iron and manganese. Further, it is preferable that at least a part of aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group (c), and the spinel crystalline composite oxide includes, for example, aluminum, zinc, iron And can be produced by firing a support on which at least one metal selected from the group consisting of manganese is supported.

A spinel structure is a structure found in an oxide having a chemical formula of XY ₂ O ₄ , belongs to a cubic system, and Al, Zn, Fe, and Mn are ZnAl ₂ O ₄ , FeAl ₂ O ₄ , and MnAl ₂ O, respectively. It is known to form _four spinel structures. Although the reason for the nitrous oxide decomposition catalyst of the present invention is not clear, at least a part of aluminum is a part or all of at least one metal selected from the group (c) and a spinel-type crystalline composite oxide. It is considered that by forming, the effect of improving the resolution of nitrous oxide and reducing the amount of NO _x generated is exhibited.

The carrier used for the catalyst of (3) is silica alumina and is not particularly limited, but those having a surface area of about 50 to 300 m ² / g can be used. The at least one metal selected from the group (d) consisting of magnesium, zinc, iron and manganese supported on the silica-alumina carrier is preferably contained in an amount of 0.1 to 5.0% by mass of the total catalyst mass, and more preferably Is preferably contained in an amount of 0.2 to 1.0% by mass. Even if the metal selected from the group (d) is contained in an amount of 5.0% by mass or more of the entire catalyst mass, the effect may be saturated.

(3) The aluminum contained in the catalyst is preferably contained in an atomic ratio of at least 2 to at least one metal selected from the group (d) consisting of magnesium, zinc, iron and manganese. Further, it is preferable that at least a part of aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group (d). The spinel type crystalline composite oxide can be produced by supporting at least one metal selected from the group (d) on a silica alumina support and firing the support.

The at least one noble metal selected from the group (a) consisting of rhodium, ruthenium and palladium contained in the nitrous oxide decomposition catalyst of the present invention may be any of the above-mentioned catalysts (1) to (3). The content is preferably 0.05 to 10% by mass, more preferably 0.1 to 6.0% by mass based on the total mass of the catalyst. Although it is possible to improve the catalytic activity at low temperature by increasing the amount of at least one noble metal selected from the group (a), it is not preferable to support 10% by mass or more in view of the cost of the catalyst, Further, if it is 0.05% by mass or less, sufficient nitrous oxide decomposition activity may not be obtained.

Next, the manufacturing method of the nitrous oxide decomposition catalyst of this invention is demonstrated.
Various production methods can be used for the nitrous oxide decomposition catalyst of the present invention. For example, methods such as (1) impregnation method, (2) coprecipitation method, and (3) kneading method can be used. Hereinafter, a method for producing the catalyst (2) using the impregnation method will be described, but it is needless to say that the present invention is not limited thereto.

The method of producing the catalyst of (2) using the impregnation method can include the following three steps.
[1] A step of supporting (b) aluminum and (c) at least one metal selected from the group consisting of zinc, iron and manganese on a silica support.
[2] A step of calcining the carrier obtained from step [1] at 400 to 900 ° C.
[3] A step of (a) supporting at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium on the calcined carrier obtained from the step [2].

In step [1], an inorganic acid salt of aluminum and at least one metal inorganic acid salt selected from the group (c) consisting of zinc, iron and manganese (nitrate, hydrochloride, sulfate, etc.) Alternatively, impregnation with an organic acid salt (oxalate, acetate, etc.). Preferably, both the aluminum and the salt of at least one metal selected from the group (c) are nitrates.

The amount of aluminum and at least one metal selected from group (c) supported on the carrier is preferably such that aluminum is supported at an atomic ratio of at least 2 with respect to at least one metal selected from group (c). In addition, it is preferable that the supported amount of at least one metal selected from the group (c) is 0.1 to 5.0% by mass of the entire catalyst mass.

After carrying out step [1], preferably the support is dried and further subjected to calcination step [2] to contain at least one metal selected from the group consisting of aluminum and group (c). A carrier in which a part forms a spinel crystalline composite oxide with at least one metal selected from the group (c) consisting of zinc, iron and manganese can be obtained. The drying temperature after step [1] is not particularly limited, but is preferably in the temperature range of 80 to 150 ° C, more preferably in the temperature range of 100 to 130 ° C. The drying atmosphere is not particularly limited, but air is preferably used. The drying time is not particularly limited, but when using the impregnation method, it may usually be about 2 to 4 hours.

The firing step [2] can be performed in a temperature range of 400 to 900 ° C., preferably 500 to 700 ° C. When the firing temperature is lower than 400 ° C., crystallization may not be sufficient, and when it is 900 ° C. or higher, the specific surface area of the carrier tends to decrease, which is not preferable. The firing time is not particularly limited, but may be about 1 to 10 hours, preferably about 2 to 4 hours, and the firing temperature may be changed stepwise. Long-time firing may be saturated economically because the effect may be saturated, and short-time firing may be less effective. Moreover, baking can be performed using a baking furnace, a muffle furnace, etc., and any of nitrogen or air may be used as a distribution gas at this time.

Next, in the carrier obtained by the step [2], at least a part of the aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group (c) consisting of zinc, iron and manganese. And [3] carrying a salt of at least one noble metal selected from the group (a) consisting of rhodium, ruthenium and palladium. As the salt of at least one noble metal selected from the group (a), an inorganic acid salt (nitrate, hydrochloride, sulfate, etc.) or an organic acid salt (oxalate, acetate, etc.) can be used. Preference is given to using the nitrate salt.

The step [3] is performed on the support obtained in the step [2] in which at least a part of aluminum forms a spinel crystalline complex oxide with at least one metal selected from the group (c). Although it is preferable, it may be performed simultaneously with the step [1]. In that case, the process [1] and the process [3] are performed at the same time, and then the process [2] is performed. At least a part of the aluminum is at least one metal selected from the group (c) and the spinel crystalline composite. It is preferable to form an oxide. In any case, it is preferable that the supported amount of at least one noble metal selected from the group (a) consisting of rhodium, ruthenium and palladium is 0.05 to 10% by mass based on the total mass of the catalyst. .

Next, the catalyst precursor subjected to step [3] is dried under the same drying conditions as described above. The dried catalyst precursor is preferably subjected to a reduction treatment, and a catalyst containing at least one noble metal selected from the group (a) having high activity can be obtained by the reduction treatment. The reduction treatment can be performed by, for example, (1) a method of re-drying after hydrazine reduction and firing, or (2) a method of hydrogen reduction, and a method of hydrogen reduction is preferably used. When using the hydrogen reduction method, the reduction temperature is preferably 200 to 500 ° C., more preferably 300 to 400 ° C. Although the reduction time is not particularly limited, the treatment can be performed in about 1 to 10 hours, preferably about 2 to 4 hours. The dried catalyst precursor may be calcined in nitrogen or air without the reduction treatment (1) or (2). The firing temperature at this time is preferably 200 to 500 ° C., more preferably 300 to 400 ° C.

Next, a method for decomposing nitrous oxide using the above nitrous oxide decomposition catalyst will be described.
The nitrous oxide decomposition method of the present invention includes the following four methods. The nitrous oxide decomposition method (1) of the present invention is characterized in that a gas containing nitrous oxide is brought into contact with the catalyst at 200 to 600 ° C. Further, the nitrous oxide decomposition method (2) of the present invention is a catalyst in which at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium is supported on a support made of silica or silica alumina. Yes, the gas containing nitrous oxide and the catalyst are brought into contact with each other at 200 to 600 ° C. When a decrease in the activity of the catalyst is observed in the decomposition process, the supply of the gas containing nitrous oxide is stopped and 500 ° C. It is characterized by restarting the supply of gas containing nitrous oxide after heating to ˜900 ° C. to activate and regenerate the catalyst.

In the method for decomposing nitrous oxide (3) of the present invention, the catalyst is silica and the support includes (a) at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium, and (b) aluminum. And (c) a catalyst carrying at least one metal selected from the group consisting of zinc, iron and manganese, contacting the gas containing nitrous oxide with the catalyst at 200 to 600 ° C. for decomposition When a decrease in the activity of the catalyst is observed in the process, the supply of the gas containing nitrous oxide is stopped and heated to 500 ° C. to 900 ° C., and the catalyst is activated and regenerated. The supply is resumed.

In the nitrous oxide decomposition method (4) of the present invention, the catalyst is a silica alumina carrier, and (a) at least one noble metal selected from the group consisting of rhodium, ruthenium and palladium, and (D) A catalyst which carries at least one metal selected from the group consisting of magnesium, zinc, iron and manganese, which is brought into contact with the gas containing nitrous oxide at 200 to 600 ° C. for decomposition. When a decrease in the activity of the catalyst is observed in the process, the supply of the gas containing nitrous oxide is stopped and heated to 500 ° C. to 900 ° C., and the catalyst is activated and regenerated. The supply is resumed.

In the nitrous oxide decomposition method of the present invention, the contact temperature between the nitrous oxide-containing gas and the decomposition catalyst is 200 to 600 ° C., preferably 300 to 500 ° C., more preferably 350 ° C. to 450 ° C. It is desirable to do. When the contact temperature is lower than 200 ° C., decomposition of nitrous oxide may not be sufficient, and when it is 600 ° C. or higher, the catalyst life tends to be short. The catalyst bed system is not particularly limited, but a fixed bed can be employed.

As the composition of the gas containing nitrous oxide, the concentration of nitrous oxide contained in the exhaust gas discharged from factories and incineration facilities is usually 1000 ppm or less, but it is discharged by the surplus anesthetic gas exclusion device in the operating room. The concentration of nitrous oxide is very high, about 8-50%. Moreover, since 13 to 20% of oxygen is usually present in the excess anesthetic gas, it is a severe condition for the decomposition catalyst. If heat removal is possible and the temperature can be controlled, the concentration of nitrous oxide contacted with the cracking catalyst is not particularly limited. However, since the reaction that decomposes nitrous oxide into nitrogen and oxygen is an exothermic reaction, nitrous oxide The concentration is preferably 50% or less, preferably 25% or less, and more preferably about 5%. Space velocity is the amount of gas supplied per unit catalyst (Space Velocity) is ^preferably in the range of 10hr ^-1 ~ 20000hr -1, more preferably from ^{100 hr} -1 ~ 10000 hr ^-1 is preferred.

In addition, the gas containing nitrous oxide may contain a volatile anesthetic, but the nitrous oxide decomposition catalyst of the present invention is not easily poisoned by the volatile anesthetic and is also poisoned by the volatile anesthetic. Even when the catalytic activity is reduced due to the above, by using the decomposition method of the present invention, the catalytic activity can be recovered and nitrous oxide can be decomposed over a long period of time. Therefore, when a decrease in the activity of the nitrous oxide decomposition catalyst is observed, the supply of the gas containing nitrous oxide is once stopped, the catalyst is activated to regenerate by calcination, and then the nitrous oxide is contained. The supply of gas can be resumed.

The calcination treatment for activating and regenerating the catalyst can be performed at a temperature of 500 to 900 ° C., preferably a decomposition catalyst whose activity is reduced at a temperature of 600 to 800 ° C., more preferably 650 to 750 ° C. . During the firing treatment, an inert gas such as helium or nitrogen or air can be circulated through the catalyst layer, and oxygen may be contained in the inert gas. It is convenient and preferable to use air. The firing treatment time is 10 minutes to 12 hours, preferably 20 minutes to 6 hours, more preferably about 30 minutes to 2 hours. Of the catalysts supporting at least one noble metal selected from the group (a) consisting of rhodium, ruthenium and palladium, the catalyst is less susceptible to poisoning by volatile anesthetics and the activity of the catalyst is easily recovered. It is a catalyst containing ruthenium, and there is a tendency that the activity decreases in the order of rhodium and palladium. Therefore, it is desirable to use at least ruthenium as the noble metal component selected from the group (a). Further, after the baking treatment, a reduction treatment with hydrogen may be performed.

The catalyst used in the decomposition method (3) of the present invention comprises at least one metal selected from the group (c) consisting of zinc, iron, and manganese among the components supported on the silica support, in an amount of 0.1% of the total catalyst mass. It is preferably contained in an amount of ˜5.0% by mass, more preferably 0.2-1.0% by mass. Even if the metal selected from the group (c) is contained in an amount of 5.0% by mass or more based on the total mass of the catalyst, the effect may be saturated.

The catalyst used in the decomposition method (4) is a catalyst comprising at least one metal selected from the group (d) consisting of magnesium, zinc, iron and manganese supported on a silica-alumina carrier in an amount of 0.1 to The content is preferably 5.0% by mass, more preferably 0.2 to 1.0% by mass. Even if the metal selected from the group (d) is contained in an amount of 5.0% by mass or more of the entire catalyst mass, the effect may be saturated.

Further, it is preferable that aluminum is contained in an atomic ratio of at least 2 with respect to at least one metal selected from the group (d) consisting of magnesium, zinc, iron and manganese. Further, it is preferable that at least a part of aluminum forms a spinel crystalline composite oxide with at least one metal selected from the group (d). The spinel type crystalline composite oxide can be produced by supporting at least one metal selected from the group (d) on a silica alumina support and firing the support.

At least one noble metal selected from the group (a) consisting of rhodium, ruthenium and palladium contained in the catalyst used in the nitrous oxide decomposition method of the present invention is any of the decompositions (1) to (4) above Even when the method is used, it is preferably contained in an amount of 0.05 to 10% by mass, more preferably 0.1 to 6.0% by mass based on the total mass of the catalyst. Although it is possible to improve the catalytic activity at low temperature by increasing the amount of at least one noble metal selected from the group (a), it is not preferable to support 10% by mass or more in view of the cost of the catalyst, Further, if it is 0.05% by mass or less, sufficient nitrous oxide decomposition activity may not be obtained.

Hereinafter, the effects of the present invention will be made clearer by examples. In addition, this invention is not limited to a following example, In the range which does not change the summary, it can change suitably and can implement.

In this example, a catalyst for decomposing nitrous oxide (made by Showa Denko KK, alumina carrier (manufactured by JGC Universal Co., Ltd.) with 5% rhodium and 1% zinc, granular, average particle size: 3 .2 mm) packed in 2.12 g (4 ml) decomposition reactor (nickel reaction tube, 1/2 inch diameter, catalyst layer height 57 mm) at about 350 ° C. with a heater (ceramic electric tubular furnace, 100 V, 500 W) The nitrous oxide gas was decomposed while supplying a nitrous oxide (N ₂ O) gas having a concentration of 100% by downflow to the decomposition reactor.

Further, when supplying the nitrous oxide gas to the decomposition reactor, the flow rate was adjusted in a range of 20 to 2422 cc / min by a flow rate adjusting valve. Then, the linear velocity (LV: Linear Velocity) [m / min] and the space velocity (SV) [hr ⁻¹ ] of the nitrous oxide gas supplied to the decomposition reactor at that time are measured, and The maximum value max [° C.] of the exothermic temperature (catalyst temperature) in the reaction vessel after decomposing the nitrogen oxide gas was measured with a temperature measuring device. Further, the amount of the NO _X after decomposing nitrous oxide gas [ppm] was measured to determine the degradation rate of the nitrous oxide gas [%]. Table 1 shows a summary of the measurement results. Moreover, the graph which put together the relationship between the linear velocity (LV) of nitrous oxide gas, the exothermic temperature in reaction container, and the decomposition rate of nitrous oxide gas from the measurement result of Table 1 is shown in FIG.

As shown in Table 1 and FIG. 8, by adjusting the flow rate of the nitrous oxide gas supplied to the above-described decomposition reactor, a high decomposition rate (99% or more) even with a nitrous oxide gas having a concentration of 100% ) Was able to decompose nitrous oxide gas.

In addition, heating by the heater was stopped under the conditions of LV = 12.75 m / min and SV = 17190 hr ⁻¹ shown in Table 1 above, and the exothermic temperature and sub-oxidation in the reaction vessel after 1 hour (hr) The decomposition rate of nitrogen gas was measured.

As a result, nitrous oxide has the same decomposition rate (98.7%) as that during heating while maintaining the heat generation temperature in the reaction vessel by the decomposition heat generated by the decomposition of nitrous oxide gas even after the heater is stopped. It turns out that the decomposition of the gas can be continued. For this reason, about 1 hour (hr) after the heater stopped, the supply of the nitrous oxide gas was stopped and the decomposition of the nitrous oxide gas was forcibly terminated. From this, it was found that the decomposition heat generated by the decomposition of the nitrous oxide gas can continue the decomposition of the nitrous oxide gas supplied thereafter without heating by the heater.

According to the present invention, by using energy generated by decomposition of nitrous oxide, it is possible to use nitrous oxide as energy friendly to the global environment. Further, since nitrous oxide is finally decomposed into nitrogen and oxygen as a decomposition gas, this decomposition gas can be utilized as a new resource. Furthermore, since nitrous oxide can also be industrially produced, its industrial utility value is very high in the present invention.

As described above, nitrous oxide is a stable gas at normal temperature and atmospheric pressure, and since it has low toxicity, it is highly safe and easy to handle. In addition, as a liquefied high-pressure gas filled in a high-pressure gas container, it can be easily transported and stored before decomposition.

In addition, nitrous oxide has a low melting point (about −90 ° C.) and does not freeze in outer space. Therefore, nitrous oxide does not stop its use on the earth, and other celestial bodies (such as the moon and Mars) and outer space (for example, It can also be used on a space station or spaceship.

Furthermore, in the present invention, since nitrous oxide can be decomposed into nitrogen and oxygen, for example, in the space environment such as a space station and a spacecraft, and in the sea environment such as a submarine station and a submarine, energy required for space activities and underwater activities is obtained. It can be used not only as a supply source, but also as a supply source of respiratory gas necessary for life support.

In the present invention, oxygen obtained by decomposing nitrous oxide can be combined with an appropriate fuel such as hydrogen or methanol to be used for a fuel cell (primary cell), for example. Further, it can be combined with a battery (secondary battery) or the like.

DESCRIPTION OF SYMBOLS 1 ... Cracking gas boiler 2 ... Steam turbine 4 ... Condenser 5 ... Feed water pump 6 ... Decomposition reaction part 7 ... Steam generation part
11 ... Decomposition gas turbine 13 ... Decomposition reaction part 14 ... Turbine part
DESCRIPTION OF SYMBOLS 21 ... Catalyst for nitrous oxide decomposition 22 ... Decomposition reactor (decomposition reaction part) 22a ... Main-body part 22b ... Gas introduction port 22c ... Gas discharge port 23 ... Fuel gas supply line (fuel gas supply means) 24 ... Nitrogen gas supply line (Nitrogen gas supply means, concentration adjustment means) 25 ... Flow rate adjustment part (flow rate adjustment means) 26 ... Temperature measuring device (temperature measurement means) 27 ... Control part (control means) 28 ... Heater (preheating means) 29 ... Power supply line DESCRIPTION OF SYMBOLS 30 ... Fuel gas on-off valve 31 ... Fuel gas supply source 31a ... High pressure gas container 32 ... Nitrogen gas on-off valve 33 ... Nitrogen gas supply source 33a ... High pressure gas container
DESCRIPTION OF

SYMBOLS

80, 80A ... Heat pump 81 ... Refrigerant circulation system 82 ... Compression part 83 ... Condensing part 84 ... Expansion part 85 ...

Evaporation part

86, 87 ... Fan (air blowing means) 88 ... Four-way valve (switching means) 89 ... Indoor unit 90 ... Outdoor Machine R ... Refrigerant

Claims

A cracked gas boiler that generates steam by recovering heat from the cracked gas generated by the decomposition of nitrous oxide;
A steam turbine that is rotationally driven by steam generated in the cracked gas boiler;
A heat transport device comprising: a heat pump that transports heat by driving the steam turbine.
A cracked gas turbine that is rotationally driven by cracked gas generated by the decomposition of nitrous oxide;
A heat transport device comprising: a heat pump that transports heat by driving the cracked gas turbine.
The cracking gas boiler or cracking gas turbine is provided with a cracking reaction section in which a nitrous oxide cracking catalyst for cracking the nitrous oxide is disposed, and a fuel gas supply for supplying fuel gas containing nitrous oxide to the cracking reaction section Means and
In the decomposition reaction section, after decomposing nitrous oxide contained in the fuel gas using the nitrous oxide decomposing catalyst, the fuel supplied thereafter by the decomposition heat generated by the decomposition of the nitrous oxide The heat transport apparatus according to claim 1 or 2, wherein the decomposition of nitrous oxide in the gas is continued.
The cracked gas boiler or cracked gas turbine comprises a flow rate adjusting means for adjusting the flow rate of the fuel gas supplied to the cracking reaction section,
The heat transport device according to claim 3, wherein the temperature of the cracked gas is controlled by adjusting a flow rate of the fuel gas supplied to the cracking reaction section.
The cracked gas boiler or cracked gas turbine comprises a concentration adjusting means for adjusting the concentration of nitrous oxide contained in the fuel gas,
The heat transport apparatus according to claim 3 or 4, wherein the temperature of the cracked gas is controlled by adjusting a concentration of nitrous oxide contained in the fuel gas.
6. The heat transport apparatus according to claim 5, wherein the concentration adjusting means adjusts the concentration of nitrous oxide contained in the fuel gas by adding nitrogen to the fuel gas.
The cracked gas boiler or cracked gas turbine comprises temperature measuring means for measuring the temperature of the nitrous oxide cracking catalyst or cracked gas,
The heat transport according to any one of claims 4 to 6, wherein a flow rate adjustment by the flow rate adjustment unit or a concentration adjustment by the concentration adjustment unit is performed based on a measurement result by the temperature measurement unit. apparatus.
The cracked gas boiler or cracked gas turbine comprises preheating means for preheating the nitrous oxide cracking catalyst,
The heat transport device according to any one of claims 3 to 7, wherein the catalyst for nitrous oxide decomposition is preheated before the decomposition of the nitrous oxide is started.
The cracked gas boiler or cracked gas turbine comprises a nitrogen gas supply means for supplying nitrogen gas to the cracking reaction section,
The heat transport apparatus according to any one of claims 3 to 8, wherein nitrogen gas is supplied to the decomposition reaction section after supply of fuel gas to the decomposition reaction section is stopped.
The heat pump includes a refrigerant circulation system in which a refrigerant circulates, a compression unit that compresses and sends out the refrigerant in the refrigerant circulation system, and a condensation that releases heat from the refrigerant while condensing the refrigerant compressed in the compression unit. And an expansion unit that expands the refrigerant radiated by the condensing unit, and an evaporation unit that absorbs heat while evaporating the refrigerant expanded in the expansion unit, and the compression unit is the vapor The heat transport device according to any one of claims 1 to 9, wherein the heat transport device is driven by a turbine or a cracked gas turbine.
The heat transport device according to claim 10, wherein the heat pump includes switching means for switching a direction in which the refrigerant flows.
Generating steam in a cracked gas boiler by recovering heat from cracked gas generated by the decomposition of nitrous oxide;
Rotating the steam turbine with steam generated by the cracked gas boiler;
A heat transport method including a step of performing heat transport with a heat pump by driving the steam turbine.
Rotating the cracked gas turbine with cracked gas generated by cracking of nitrous oxide;
A heat transport method comprising: performing heat transport with a heat pump by driving the cracked gas turbine.
A fuel gas containing nitrous oxide is supplied to a decomposition reaction section in which a nitrous oxide decomposition catalyst for decomposing the nitrous oxide is disposed, and the nitrous oxide contained in the fuel gas is supplied to the decomposition reaction section. Is decomposed using the nitrous oxide decomposition catalyst, and then decomposition of nitrous oxide in the fuel gas supplied thereafter is continued by the decomposition heat generated by the decomposition of the nitrous oxide. The heat transport method according to claim 12 or 13.
The heat transport method according to claim 14, wherein the decomposition of the nitrous oxide is continuously performed by controlling the temperature of the cracked gas.
The heat transport method according to claim 15, wherein the temperature of the cracked gas is controlled by adjusting the flow rate of the fuel gas.
The heat transport method according to claim 15 or 16, wherein the temperature of the cracked gas is controlled by adjusting the concentration of nitrous oxide contained in the fuel gas.
The heat transport method according to claim 17, wherein the concentration of nitrous oxide contained in the fuel gas is adjusted by adding nitrogen to the fuel gas.
The heat transport method according to any one of claims 15 to 18, wherein the temperature of the nitrous oxide decomposition catalyst or cracked gas is measured, and the temperature of the cracked gas is controlled based on the measurement result.
The heat transport method according to any one of claims 14 to 19, wherein the nitrous oxide decomposition catalyst is preheated before the decomposition of the nitrous oxide is started.
The heat transport method according to any one of claims 14 to 20, wherein nitrogen gas is supplied to the decomposition reaction section after supply of fuel gas to the decomposition reaction section is stopped.