Treatment apparatus and treatment method

Abstract

To provide a treatment apparatus and a treatment method capable of performing mass decomposition treatment (destruction treatment) of PFOS and / or PFOA by utilizing (diverting) a treatment apparatus has have been operating in cement production from the past, without generating harmful substances in the process of that treatment.SOLUTION: A treatment apparatus 10 of the present disclosure includes: a preheater 20 that preheats a cement raw material pulverized by a raw material mill; a rotary kiln 40 (one example of a kiln) to which the preheater 20 is connected at a kiln inlet part 45, and that fires the cement raw material preheated by the preheater 20 to generate a clinker; and a delivery pipe 55 disposed in the kiln inlet part 45, having a delivery port 56 that protrudes toward the internal part of the kiln inlet part 45, to which an aqueous mixture AM containing PFOS and / or PFOA is supplied and from which the aqueous mixture AM is discharged toward the internal part of the kiln inlet part 45. The aqueous mixture AM is discharged from the delivery port 56 of the delivery pipe 55 simultaneously while generating the clinker.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a treatment facility and a treatment method for decomposing (destroying) PFOS and / or PFOA by incinerating an aqueous mixture containing PFOS and / or PFOA.

Background Art

[0002] PFOS and PFOA are known as perfluorooctane sulfonic acid and perfluorooctanoic acid, respectively. In recent years, it has become clear from research that these substances are carcinogenic, and they have become a social problem.

[0003] These chemical substances are widely used in various industrial processes and products such as household goods, and there are concerns about the environmental impact and potential health risks associated with their use. In addition, PFOS or PFOA has a chemically very stable structure and is difficult to decompose by ordinary treatment methods, remaining in the environment for a long time. Therefore, there is a strong social demand to safely and efficiently treat the decomposition of existing PFOS and PFOA that have been widely used in society until now.

[0004] As a device for destroying conventional organic fluorine compounds (such as PFAS), etc., there is known one comprising a first inlet conduit for passing a PFAS-containing aqueous stream through a mixing joint, a second inlet conduit for passing a heated stream of clean water through the mixed stream, a conduit connecting the mixing T-joint to the inlet of the SCWO reactor, and an outlet of the SCWO reactor connected to a salt separator (see, for example, Patent Document 1).

[0005] In that apparatus, the salt separator includes an effluent outlet, and the effluent outlet is configured to pass clean water to a heat exchanger. The heat exchanger is configured to heat the clean water that exits the heat exchanger and enters a mixing T-joint. Alternatively, the effluent outlet is configured to pass the effluent to the mixing T-joint.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, when using the technology as shown in the aforementioned Patent Document 1, it is necessary to newly introduce equipment for each region to treat chemical substances such as PFOS or PFOA. Also, when treating a large amount, since it is new equipment and its structure is large and complex, the treatment cost may become extremely large.

[0008] On the other hand, regarding the treatment of PFOS and PFOA, it is efficient and reasonable in terms of society and economy if it is possible to utilize (divert) the equipment already used in normal social production activities. By utilizing the existing equipment, there is no need to newly introduce equipment, and it becomes possible to reduce the treatment cost. Also, there is a possibility of reducing the environmental load due to it being an established technology and so on.

[0009] By the way, cement equipment is an important existence (social function) as social infrastructure such as supplying the basic materials of buildings or structures. Its advantages are diverse.

[0010] For example, one of them is the ability to handle large amounts of processing. The cement facility is configured to be able to quickly supply the cement required for building materials by an automated production line. Furthermore, the cement facility also has advantages in the treatment of industrial waste. The waste generated at construction sites and the like can be reused as components of cement, and by treating the industrial waste as a raw material for cement in the cement facility, it is possible to reduce waste and at the same time effectively utilize resources. Furthermore, in recent years, technologies for recovering energy from the treatment of such industrial waste have also advanced, and it is also being done to convert waste into useful energy resources while minimizing the environmental impact.

[0011] As such, the cement facility has various advantages, and it can be said that there is room for improvement in terms of utilizing the cement facility for the treatment technology of PFOS and / or PFOA.

[0012] The present invention has been made in view of the above-described circumstances, and the object thereof is to utilize (divert) the treatment facility that has been operating in cement production hitherto, and to decompose (destroy) a large amount of PFOS and / or PFOA without generating harmful substances during the treatment process. It is to provide a treatment facility and a treatment method that can be processed.

Means for Solving the Problems

[0013] The above-described object of the present invention is achieved by the following configuration. [1] A preheater for preheating cement raw materials pulverized in a raw material mill, A kiln in which the preheater is connected to the kiln end portion and the cement raw materials preheated by the preheater are fired to produce clinker, A discharge pipe disposed at the kiln end portion, the discharge port of which protrudes toward the inside of the kiln end portion, and into which an aqueous mixture containing PFOS and / or PFOA is supplied and the aqueous mixture is discharged from the discharge port toward the inside of the kiln end portion, While generating the clinker, the aqueous mixture is discharged from the discharge port of the discharge pipe at the same time. Processing equipment. [2] An exhaust duct standing vertically upward is connected to the kiln end portion. Exhaust gas generated in the kiln flows through the exhaust duct. Based on the main body portion of the kiln, the main body portion of the exhaust duct, and the intersection of the first direction which is the extending direction of the kiln and the second direction which is the extending direction of the exhaust duct, the discharge pipe is disposed on the wall surface of the kiln end portion on the side opposite to the main body portion of the kiln and on the exhaust duct side. The processing equipment according to [1]. [3] An exhaust duct standing vertically upward is connected to the kiln end portion. Exhaust gas generated in the kiln flows through the exhaust duct. Based on the main body portion of the kiln, the main body portion of the exhaust duct, and the intersection of the first direction which is the extending direction of the kiln and the second direction which is the extending direction of the exhaust duct, the discharge port is offset and disposed closer to the side opposite to the main body portion of the kiln in the internal space of the kiln end portion. The processing equipment according to [1]. [4] The central axis of the discharge direction of the discharge port is set to be inclined upward so as to face the main body side of the exhaust duct. The processing equipment according to [3]. [5] The discharge pipe discharges the aqueous mixture radially from the discharge port. The processing equipment according to [4]. [6] A storage tank for storing the aqueous mixture. Further including a pressure pump connected to the discharge pipe for pumping and supplying the aqueous mixture in the storage tank. The processing equipment according to [1]. [7] The pressure pump continuously supplies the aqueous mixture to the discharge pipe. The processing equipment described in [6]. [8] A preheater for preheating a cement raw material pulverized by a raw material mill, A kiln connected to the kiln end of the preheater for firing the cement raw material preheated by the preheater to produce clinker, An exhaust duct connected to the kiln end and erected along the vertical upward direction, A discharge pipe disposed at the lower end of the exhaust duct, with its discharge port protruding toward the inside of the exhaust duct, and an aqueous mixture containing PFOS and / or PFOA is supplied to discharge the aqueous mixture from the discharge port toward the inside of the exhaust duct, While producing the clinker, simultaneously discharging the aqueous mixture from the discharge port of the discharge pipe, Processing equipment. [9] A preheating step of preheating a cement raw material pulverized by a raw material mill using a preheater, A firing step of firing the cement raw material preheated by the preheater to produce clinker using a kiln connected to the kiln end of the preheater, A discharging step of supplying an aqueous mixture containing PFOS and / or PFOA to a discharge pipe disposed at the kiln end with its discharge port protruding toward the inside of the kiln end and discharging the aqueous mixture from the discharge port toward the inside of the kiln end, Executing the preheating step, the firing step, and the discharging step in parallel, Processing method.

[0014] According to the configurations of [1] and [9] above, by utilizing (diverting) the processing equipment that has been operating in cement production, chemical substances such as PFOS and / or PFOA can be decomposed (destroyed) without generating harmful substances during the processing. Also, while manufacturing cement, PFOS and / or PFOA can be decomposed simultaneously, enabling efficient processing with good economic efficiency. Furthermore, a large amount of PFOS and / or PFOA can be processed. Here, there is a location where the flow path bends (curves) between the kiln end portion and the flow path of the exhaust duct. In this curved portion, the exhaust gas flowing from the kiln end to the exhaust duct has a higher flow velocity on the outer side compared to the inner side of the curve. Therefore, according to the configuration of [2] above, the discharged aqueous mixture rides on the flow of the outer exhaust gas with a high flow velocity and is incinerated, so that its destruction can be surely carried out during the decomposition process (destruction process) to suppress the generation of harmful substances. Also, since the aqueous mixture does not flow towards the kiln side, a decrease in the operating temperature of the kiln can be suppressed. According to the configuration of [3] above, the discharged aqueous mixture rides on the outer exhaust gas with a high flow velocity and is processed, so that its destruction can be surely carried out during the decomposition process (destruction process) to suppress the generation of harmful substances. Also, since the aqueous mixture does not flow towards the kiln side, a decrease in the operating temperature of the kiln can be suppressed. According to the configuration of [4] above, it is possible to ride on the flow of the exhaust gas from the kiln and minimize the contact with the cement raw materials. As a result, the operating impact on cement production and the cooling of the operating temperature of the kiln can be suppressed. According to the configuration of [5] above, it is possible to suppress the cooling of the operating temperature of the kiln, minimize the operating impact on cement production, and enhance the efficiency of the decomposition process (destruction process) of PFOS and / or PFOA. According to the configuration of [6] above, it is preferable to further include a storage tank for storing an aqueous mixture and a pumping pump connected to a discharge pipe for pumping and supplying the aqueous mixture in the storage tank. In this case, the aqueous mixture can be efficiently and continuously supplied to the bottom part of the kiln, and a larger amount of decomposition treatment (destruction treatment) of PFOS and / or PFOA can be performed. According to the configuration of [7] above, since the aqueous mixture supplied toward the inside of the bottom part of the kiln is continuously supplied, fluctuations in the temperature load of the equipment associated therewith can be suppressed, and stable operation of the kiln can be maintained and continued. Also in the case of the configuration of [8] above, the same operational effects as those of the configurations of [1] and [9] can be achieved.

Advantages of the Invention

[0015] According to the present invention, by utilizing (reusing) the processing equipment that has been operating in cement production, PFOS and / or PFOA can be decomposed (destroyed) in large quantities without generating harmful substances during the processing.

[0016] The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading through the embodiments (hereinafter referred to as "embodiments") for carrying out the invention described below with reference to the accompanying drawings.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Embodiments for Carrying Out the Invention

[0018] Hereinafter, with appropriate reference to the accompanying drawings, one or more embodiments specifically disclosing the processing equipment and processing method according to the present invention will be described in detail.

[0019] However, detailed descriptions that are more detailed than necessary may be omitted. For example, detailed descriptions of well-known matters and redundant descriptions of substantially the same configurations may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate the understanding of those skilled in the art.

[0020] Note that the accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and it is not intended to limit the subject matter described in the claims thereby. Also, each of the accompanying drawings shall be referred to according to the orientation of the reference signs.

[0021] Also, unless otherwise specified, all numbers representing parameters, reaction conditions, concentrations of components, etc. used in this specification and the appended claims should be understood to be modified by the term "about" in all examples. Therefore, unless otherwise indicated, the numerical parameters shown in the following specification and the appended claims are approximations that may vary depending at least on specific analytical techniques.

[0022] <Explanation of Terms> The term "comprising", which is synonymous with "including" and "characterized by", is to be construed in an inclusive or open-ended sense and does not exclude additional, unrecited elements or method steps. "Comprising" is a technical term used in claim language, which means that the recited claim elements are essential, but other claim elements may be added to further form a composition within the scope of the claim.

[0023] Also, as used herein, the phrase "consisting of" excludes any element, step or component not specified in the claims. When the phrase "consisting of (or a variation thereof)" appears in a clause of the body of a claim rather than immediately following the preamble, it limits only the elements shown in that clause and does not exclude other elements from the entire claim. The phrase "consisting essentially of" as used herein limits the scope of a claim to those things that do not substantially affect the basic components and novel features (singular or plural) of the claimed subject matter in addition to the specified elements or method steps.

[0024] Regarding the terms "comprising", "consisting of" and "consisting essentially of", when one of these three terms is used herein, the subject matter disclosed and claimed in the present invention may also include the use of either of the other two terms. Thus, in some embodiments not explicitly stated otherwise, any instance of "comprising" may be replaced by "consisting of" or "consisting essentially of".

[0025] The term "process" or "step" may be used explicitly or implicitly in relation to the features of a process or method. However, unless the order or procedure is specified, the order or procedure between such explicit or implicit processes or steps is not limited.

[0026] <PFOS and PFOA> The objects to be processed in the present invention are PFOS and PFOA. These substances will be described.

[0027] PFOS (Per Fluoro Octane Sulfonic acid, perfluorooctanesulfonic acid) and PFOA (Per Fluoro Octanoic Acid, perfluorooctanoic acid) are a type of organic fluorine compound and are surfactants with excellent heat resistance, chemical resistance, and stain resistance. Since the 1950s, they have been used in various fields such as semiconductor manufacturing, metal plating, foam fire extinguishing agents, ant killers, fluororesin manufacturing, textiles, medicine, and food packaging paper.

[0028] However, in recent years, concerns about the environment and health related to PFOS and PFOA have been increasing, and recent research has revealed that they are widely distributed in the ecosystem. These chemical substances have low biodegradability and can remain in soil and water for a long time and may accumulate in organisms. It has also been pointed out that they may have an adverse impact on humans through the food chain due to bioaccumulation or effects on the ecosystem.

[0029] Animal experiments have suggested possibilities such as carcinogenicity, endocrine disruption, and immunosuppression, and international regulations and efforts are being considered. In such a situation, the use of these chemical substances is being restricted, but in reality, the decomposition treatment (destruction treatment) of existing PFOS and PFOA that are currently in use is also an urgent matter.

[0030] Thus, PFOS and PFOA have been pointed out to have adverse effects on the environment and potential risks to the human body, and technologies for safely and massively destroying these chemical substances are strongly demanded socially.

[0031] The present invention has a special configuration as described in one or more of the following embodiments in order to decompose (destroy) PFOS and / or PFOA in large quantities without generating harmful substances during the treatment process.

[0032] <First Embodiment> Based on FIGS. 1 to 3, a first embodiment of the treatment facility 10 according to the present invention will be described.

[0033] [Regarding the outline of the equipment] With reference to FIG. 1, an example of the configuration of the processing equipment 10 according to the present embodiment will be described. FIG. 1 is a schematic diagram for explaining an example of the structure of the processing equipment 10 of the present embodiment.

[0034] As shown in FIG. 1, the processing equipment 10 of the present embodiment is mainly composed of cement equipment. That is, in the present embodiment (the present invention), PFOS and / or PFOA are decomposed (destroyed) using (diverting) cement equipment to detoxify them.

[0035] The processing equipment 10 consists of a cement clinker firing facility, and includes a preheater 20, a precalciner 30, and a rotary kiln 40 (an example of a kiln).

[0036] The rotary kiln 40 heats the cement raw material preheated and precalcined by the preheater 20 or the like to, for example, a temperature of 1300 °C or higher and causes a firing reaction to produce (fire) cement clinker (clinker) as described later. The rotary kiln 40 is formed in a cylindrical shape and is installed extending along the horizontal direction. The rotary kiln 40 operates while rotating (rolling). Note that the rotary kiln 40 is arranged with a slight inclination with respect to the installation surface (ground).

[0037] Further, the rotary kiln 40 has a kiln tail portion 45 and a kiln front portion 41. A main burner (not shown) is disposed at the kiln front portion 41 of the rotary kiln 40. The main burner blows pulverized coal into the kiln front portion 41 of the rotary kiln 40 to maintain and continue the combustion reaction (combustion phenomenon). Further, a kiln hood portion 42 is disposed at the kiln front portion 41 of the rotary kiln 40. The kiln hood portion 42 is continuous with the cooler device 43.

[0038] That is, in the rotary kiln 40, the cement raw material is fired at a predetermined temperature, and the fired cement clinker is transferred from the front part 41 of the kiln to the cooler device 43, cooled (lowered in temperature), and discharged. Further, at the rear end part 45 of the kiln, it is connected to the preheater 20, and the cement raw material preheated by the preheater 20 is supplied to the main body part of the rotary kiln 40 through the rear end part 45.

[0039] Note that in the rotary kiln 40 of the present embodiment, for example, after firing the cement raw material up to a maximum temperature of about 1,450°C, it is cooled down to about 125°C at once by the aforementioned cooler, but it is not limited to this temperature setting and is adaptively selected and set in consideration of the properties of the cement raw material or external environments such as the weather.

[0040] The preheater 20 introduces the high-temperature exhaust gas discharged from the calciner 30 as described later, and heats up and preheats the cement raw material pulverized by a raw material mill (not shown) to, for example, 800 to 900°C. Further, the preheater 20 of the present embodiment is a multi-stage cyclone type in which a plurality of cyclones 21 are connected in multiple stages in the vertical direction. The uppermost cyclone 21 and the third exhaust duct DC3 connecting the second cyclone 21 from the uppermost one are provided. An inlet 22 for charging the cement raw material is arranged in the third exhaust duct DC3. Further, a chute ST is arranged between the lowermost cyclone 21 and the rotary kiln 40. The cement raw material preheated by the preheater 20 passes through this chute ST and is charged into the rear end part 45 of the rotary kiln 40. The charged cement raw material is fired in the rolling rotary kiln 40 and finally becomes cement clinker. Note that in the present embodiment, the inlet 22 is arranged between the uppermost cyclone 21 and the second cyclone 21, but it is not limited to this.

[0041] The calciner 30 introduces the high-temperature gas discharged from the rotary kiln 40 and burns the preheated cement raw materials by injecting fuel. A plurality of sub-burners (not shown) and inlets (not shown) are arranged at the lower part of the calciner 30. Each of the plurality of sub-burners blows pulverized coal into the interior of the calciner 30. Solid combustible waste such as industrial waste is charged into the inlet of the calciner 30.

[0042] Further, the calciner 30 has a first exhaust duct DC1 (an example of an exhaust duct) and a second exhaust duct DC2. The first exhaust duct DC1 is erected along the vertically upward direction and connects and communicates with the lower end of the calciner 30 and the kiln end portion 45 of the rotary kiln 40. That is, the first exhaust duct DC1 is connected to the kiln end portion 45, and the exhaust gas generated in the rotary kiln 40 flows (is introduced) through the first exhaust duct DC1. The second exhaust duct DC2 connects and communicates with the upper end of the calciner 30 and the side wall of the lowermost cyclone 21.

[0043] In the calciner 30, as described above, the solid combustible waste and the pulverized coal are burned. At the same time, the exhaust gas generated in the rotary kiln 40 passes through the first exhaust duct DC1 and flows into the interior of the calciner 30. Then, the exhaust gas flowing through the calciner 30 further passes through the second exhaust duct DC2 from the upper end portion of the calciner 30 and is introduced into the lowermost cyclone 21.

[0044] In the processing facility 10 configured as described above, as described above, cement clinker is produced from the cement raw materials.

[0045] Specifically, cement raw materials (such as limestone, clay, silica, iron raw materials, etc.) are introduced into the raw material mill through a dryer (drying machine) as required. These cement raw materials are pre-crushed in the raw material mill and stored, for example, in a raw material mixing and storage silo. Then, as described above, they are preheated in the preheater 20 and partially calcined in the calciner 30, and then fed into the rotary kiln 40 for cement firing. After being fired in the rotary kiln 40 to become cement clinker and cooled by the cooler device 43, they are loaded into a clinker silo (not shown).

[0046] Regarding the treatment of exhaust gas, about half of the exhaust gas from the cyclone 21 at the topmost stage of the preheater 20 flows (is transferred) to the raw material mill side. The remainder is transferred to the side of the humidifying tower (not shown). The exhaust gas transferred to the raw material mill is used for raw material drying and then passes through a dust collection cyclone (not shown) and is transferred to an electrostatic precipitator (not shown). On the other hand, the exhaust gas transferred to the humidifying tower is cooled and humidity-adjusted by spraying industrial water stored in an industrial water storage tank. Then, the exhaust gas from the raw material mill and the exhaust gas from the humidifying tower merge in front of the electrostatic precipitator, and the merged exhaust gas is mixed with each other and then dust-collected by the electrostatic precipitator. After that, the exhaust gas is finally discharged to the outside through a chimney (not shown).

[0047] In this embodiment, a discharge pipe 55 of a supply unit 50 described later is disposed at the kiln end portion 45 of the rotary kiln 40 of the treatment facility 10. While generating cement clinker as described above, at the same time, an aqueous mixture AM containing PFOS and / or PFOA is discharged from the discharge port 56 of the discharge pipe 55. By this discharge, the decomposition treatment (destruction treatment) of these chemical substances is safely and efficiently realized without generating harmful substances (see the following description).

[0048] [Regarding the configuration of the supply unit 50] With reference to FIGS. 2 and 3, an example of the configuration of the supply unit 50 will be described. FIG. 2 is an enlarged view that enlarges the periphery of the kiln end portion 45 shown in FIG. 1. FIG. 3 is an enlarged view of a main part further enlarging the periphery of the discharge port 56 of the discharge pipe 55 shown in FIG. 2.

[0049] As shown in FIGS. 2 and 3, the processing facility 10 is further configured to include a supply unit 50.

[0050] The supply unit 50 includes a storage tank 51, a pressure feed pump 52, and a discharge pipe 55, and discharges an aqueous mixture AM containing PFOS and / or PFOA (hereinafter also referred to as "aqueous mixture") into the kiln end portion 45 of the rotary kiln 40.

[0051] In this embodiment, in order to destruct PFOS and / or PFOA, a pretreatment is performed in which these chemical substances are mixed with a liquid such as water to form an aqueous mixture AM, or PFOS and / or PFOA are received as a liquid in which they are mixed as industrial waste as it is (for example, a foam fire extinguishing agent containing PFOS and PFOA). In this way, in the processing facility 10 of this embodiment, it is processed in a liquid state, that is, as an aqueous mixture AM containing PFOS and / or PFOA.

[0052] The storage tank 51 temporarily stores, for example, the aqueous mixture AM generated by pretreatment or transported from the outside. The pressure feed pump 52 is disposed, for example, at the lower part of the storage tank 51 and is connected to the discharge pipe 55 through a predetermined pipe 53. The pressure feed pump 52 applies pressure to the aqueous mixture AM stored in the storage tank 51 and continuously sends (supplies) the aqueous mixture AM to the discharge pipe 55 through the pipe 53.

[0053] The discharge pipe 55 is made of, for example, a metal pipe material and is formed by bending at its middle part. Further, the discharge pipe 55 is attached (arranged) to the kiln end portion 45 of the rotary kiln 40. Specifically, on the wall surface of the kiln end portion 45, which is on the side opposite to the main body portion of the rotary kiln 40 and located on the side of the first exhaust duct DC1, with reference to the main body portion of the rotary kiln 40, the intersection portion CP of the first direction DR1, which is the extending direction of the rotary kiln 40, and the second direction DR2, which is the extending direction of the first exhaust duct DC1, the discharge pipe 55 is arranged so as to penetrate through the front and back thereof. At that time, the tip of the bent discharge pipe 55 is arranged so as to face the inside of the kiln end portion 45 as a whole. The bent portion of the discharge pipe 55 is arranged close to the inner wall surface portion of the kiln end portion 45.

[0054] Therefore, the discharge port 56 (tip port) of the discharge pipe 55 is arranged to protrude toward the inside of the kiln end portion 45 of the rotary kiln 40, and the aqueous mixture AM is supplied from the pressure feed pump 52 and discharged from the discharge port 56 toward the inside of the kiln end portion 45. An injection nozzle (not shown) is attached to the discharge port 56 of the discharge pipe 55, and the discharge pipe 55 discharges the supplied aqueous mixture AM in a conical (circular cone) radial pattern or sprays it from the discharge port 56. The radiation angle is set to about 90°, for example. In this embodiment, the concept of injection is understood to include the meaning of spraying. Also, as described above, since the aqueous mixture AM is pressure-fed by the pressure feed pump 52, there may be a case where it is discharged in a state where injection and spraying are mixed.

[0055] Furthermore, in the present embodiment, with reference to the main body of the rotary kiln 40, the main body of the first exhaust duct DC1, and the intersection CP of the first direction DR1 and the second direction DR2, in the internal space of the kiln end portion 45, the discharge port 56 of the discharge pipe 55 is offset (shifted) and arranged closer to the side opposite to the main body of the rotary kiln 40. In other words, in the exhaust gas that is introduced into the first exhaust duct DC1 from the rotary kiln 40, is redirected, curves, and flows, the discharge port 56 is arranged so as to ride on the outer flow of the curve portion, and the aqueous mixture AM is discharged from the discharge port 56 (see the following description).

[0056] Also, due to the bent portion of the aforementioned discharge pipe 55, the central axis of the discharge direction of the discharge port 56 is provided to be inclined upward so as to face the main body side of the first exhaust duct DC1. The inclination angle A is set in the range of 30° to 60° with reference to the horizontal direction, and more preferably 45° (see FIG. 3).

[0057] [Regarding the decomposition process] With reference to FIG. 3 again, the process of decomposing PFOS and / or PFOA in the present embodiment will be described. FIG. 3 is an enlarged view of the main part further enlarging the periphery of the discharge port 56 of the discharge pipe 55 shown in FIG. 2.

[0058] The processing facility 10 of the present embodiment normally operates as a cement clinker firing facility as described above. A preheater 20 is continuously provided above the kiln end portion 45 of the rotary kiln 40, and the cement raw material pulverized by the raw material mill is preheated by this preheater 20. Then, the preheated cement raw material is dropped into the kiln end portion 45 of the rotary kiln 40 and fired in the rotary kiln 40. As a result, cement clinker is produced (manufactured). That is, the processing facility 10 of the present embodiment manufactures cement clinker as usual as a cement clinker firing facility.

[0059] At that time, as shown in FIG. 3, during the firing process in the rotary kiln 40, exhaust gas is generated in the rotary kiln 40 along with the firing, and at least a part of the exhaust gas passes through the kiln end portion 45 and is introduced into the first exhaust duct DC1. That is, at least a part of the exhaust gas from the rotary kiln 40 curves in a form that changes its direction vertically upward at the kiln end portion 45 and flows (is introduced) into the first exhaust duct DC1.

[0060] Here, as described above, the discharge pipe 55 of the supply unit 50 is disposed such that its discharge port 56 protrudes into the kiln end portion 45. Specifically, with reference to the main body portion of the rotary kiln 40, the main body portion of the first exhaust duct DC1, and the intersection portion CP of the first direction DR1 and the second direction DR2, in the internal space of the kiln end portion 45, the discharge port 56 is offset (displaced) closer to the side opposite to the main body portion of the rotary kiln 40. Further, the central axis in the discharge direction of the discharge port 56 is set to be inclined upward so as to face the main body side of the first exhaust duct DC1 (see reference sign A in FIG. 3).

[0061] And in the curved portion of the exhaust gas flow in the internal space of the kiln end portion 45, the flow velocity of the outer flow is higher than that of the inner flow of the curved portion. Therefore, in the present embodiment, the aqueous mixture AM discharged from the discharge port 56 rides on the outer flow of the curved portion of the exhaust gas described above and vigorously flows toward the first exhaust duct DC1. While riding on the fast flow and moving toward the first exhaust duct DC1, the aqueous mixture AM is incinerated at a high temperature by the combustion energy in the rotary kiln 40 and the calciner 30.

[0062] As a result, PFOS and / or PFOA contained in the aqueous mixture AM are decomposed (destroyed) without generating harmful substances. Further, in the present embodiment, the discharge direction is set to the side opposite to the rotary kiln 40, and the aqueous mixture AM is not discharged to the rotary kiln 40 side. Therefore, it is possible to suppress the cooling of the operating temperature of the rotary kiln 40, bake the cement clinker as in normal operation, and efficiently decompose PFOS and / or PFOA.

[0063] [·Regarding the features and advantages of the present embodiment] As described above, according to the processing equipment 10 of the present embodiment, a preheater 20 that preheats the cement raw material pulverized by the raw material mill, and the preheater 20 is connected to the kiln end portion 45, and the rotary kiln 40 (an example of a kiln) that bakes the cement raw material preheated by the preheater 20 to produce clinker, and a discharge pipe 55 disposed at the kiln end portion 45, the discharge port 56 of which protrudes toward the inside of the kiln end portion 45, and an aqueous mixture AM containing PFOS and / or PFOA is supplied and the aqueous mixture AM is discharged from the discharge port 56 toward the inside of the kiln end portion 45. Further, while producing clinker, the aqueous mixture AM is discharged from the discharge port 56 of the discharge pipe 55 at the same time.

[0064] Further, according to the processing method of the present embodiment, a preheating step of preheating the cement raw material pulverized by the raw material mill using the preheater 20, a firing step of firing the cement raw material preheated by the preheater 20 using a rotary kiln 40 (an example of a kiln) to which the preheater 20 is connected to the kiln end portion 45 to produce clinker, and a discharge step of supplying the aqueous mixture AM containing PFOS and / or PFOA to the discharge pipe 55 using a discharge pipe 55 disposed at the kiln end portion 45 and the discharge port 56 of which protrudes toward the inside of the kiln end portion 45 and discharging the aqueous mixture AM from the discharge port 56 toward the inside of the kiln end portion 45. Further, the preheating step, the firing step, and the discharge step are executed in parallel.

[0065] Therefore, by utilizing (diverting) the processing equipment 10 that has been operating in cement manufacturing, chemical substances such as PFOS and / or PFOA can be decomposed (destroyed) without generating harmful substances during the processing. Also, while manufacturing cement, PFOS and / or PFOA can be decomposed simultaneously, enabling efficient processing with good economic efficiency. Furthermore, a large amount of PFOS and / or PFOA can be processed.

[0066] Also, according to the processing equipment 10 of the present embodiment, a first exhaust duct DC1 (an example of an exhaust duct) erected along the vertically upward direction is connected to the kiln end portion 45. Further, exhaust gas generated in the rotary kiln 40 (an example of a kiln) flows through the first exhaust duct DC1. Also, on the wall surface of the kiln end portion 45, which is on the side opposite to the main body portion of the rotary kiln 40 and is located on the first exhaust duct DC1 side, with reference to the main body portion of the rotary kiln 40, the intersection portion CP of the first direction DR1, which is the extending direction of the rotary kiln 40, and the second direction DR2, which is the extending direction of the first exhaust duct DC1, a discharge pipe 55 is disposed.

[0067] For this reason, the discharged aqueous mixture AM rides on the flow of the outer exhaust gas with a high flow rate and is incinerated, so that its destruction can be surely executed during the decomposition process (destruction process) to suppress the generation of harmful substances. Also, since the aqueous mixture AM does not face the rotary kiln 40 (an example of a kiln) side, a decrease in the operating temperature of the rotary kiln 40 can be suppressed.

[0068] Further, according to the processing facility 10 of the present embodiment, a first exhaust duct DC1 (an example of an exhaust duct) erected along the upward vertical direction is connected to the kiln end portion 45. Further, exhaust gas generated in a rotary kiln 40 (an example of a kiln) flows through the first exhaust duct DC1. Further, the discharge port 56 is offset toward the side opposite to the main body portion of the rotary kiln 40 in the internal space of the kiln end portion 45 with reference to the main body portion of the rotary kiln 40, the main body portion of the first exhaust duct DC1, and the intersection portion CP of the first direction DR1 which is the extending direction of the rotary kiln 40 and the second direction DR2 which is the extending direction of the first exhaust duct DC1.

[0069] Therefore, since the discharged aqueous mixture AM rides on the outer exhaust gas with a high flow velocity and is processed, its destruction can be surely executed in the process of the decomposition treatment (destruction treatment) to suppress the generation of harmful substances. Further, since the aqueous mixture AM does not go toward the rotary kiln 40 (an example of a kiln) side, a decrease in the operating temperature of the rotary kiln 40 can be suppressed.

[0070] Further, according to the processing facility 10 of the present embodiment, the central axis in the discharge direction of the discharge port 56 is set to be inclined upward so as to face the main body side of the first exhaust duct DC1 (an example of an exhaust duct).

[0071] Therefore, it can ride on the flow of the exhaust gas from the rotary kiln 40 (an example of a kiln) and minimize the contact with the cement raw material. As a result, the influence on the operation of cement production and the cooling of the operating temperature of the rotary kiln 40 can be suppressed.

[0072] Further, according to the processing facility 10 of the present embodiment, the discharge pipe 55 radially discharges the aqueous mixture AM from the discharge port 56.

[0073] Therefore, it is possible to suppress the cooling of the operating temperature of the rotary kiln 40 (an example of a kiln), minimize the influence on the operation of cement production, and enhance the efficiency of the decomposition treatment (destruction treatment) of PFOS and / or PFOA.

[0074] Further, according to the processing facility 10 of the present embodiment, it is preferable to further include a storage tank 51 for storing the aqueous mixture AM and a pressure feed pump 52 connected to the discharge pipe 55 for pressure-feeding and supplying the aqueous mixture AM in the storage tank 51.

[0075] In this case, the aqueous mixture AM can be continuously supplied to the kiln end portion 45 of the rotary kiln 40 (an example of a kiln) efficiently, and a larger amount of decomposition treatment (destruction treatment) of PFOS and / or PFOA can be performed.

[0076] Further, according to the processing facility 10 of the present embodiment, the pressure feed pump 52 continuously supplies the aqueous mixture AM to the discharge pipe 55.

[0077] Therefore, since the aqueous mixture AM supplied toward the inside of the kiln end portion 45 is continuously supplied, fluctuations in the temperature load of the equipment associated therewith can be suppressed, and stable operation of the rotary kiln 40 (an example of a kiln) can be maintained and continued.

[0078] [·First Modification Example According to the Present Embodiment] In this modification example, the discharge pipe 55 is disposed at the lower end portion of the first exhaust duct DC1 (an example of an exhaust duct) instead of the kiln end portion 45. The discharge port 56 thereof protrudes toward the inside of the first exhaust duct DC1, and the aqueous mixture AM containing PFOS and / or PFOA is supplied, and the aqueous mixture AM is discharged from the discharge port 56 toward the inside of the first exhaust duct DC1. Even in this case, the same operational effects as those of the present embodiment are achieved.

Example

[0079] One or more tests are cited as examples (application examples and / or specific examples) according to the present invention, and the usefulness of the present invention will be described in more detail.

[0080] <First Example> To confirm the usefulness of the present invention, a confirmation test was conducted using a PFOS- and PFOA-containing foam fire extinguishing agent (hereinafter also referred to as "test sample") as an aqueous mixture (AM) containing PFOA and PFOS. The details of the confirmation test are shown below.

[0081] [·Test method] While firing cement clinker using equipment that has already been installed and operated as cement clinker firing equipment (test equipment), an aqueous mixture of PFOA and PFOS (AM: foam fire extinguishing agent in this example) is discharged (ejected) from the kiln end portion (45) of the rotary kiln (40). A test is conducted to incinerate these chemical substances by means of the discharge.

[0082] Then, samples are collected from multiple locations of the test equipment (see "Sampling locations of samples" described later) and evaluated.

[0083] Regarding the evaluation, for the test samples, solid matter samples, and exhaust gas samples obtained from the sampling locations, pretreatment is performed based on the "Technical Considerations for the Treatment of PFOS- and PFOA-Containing Wastes" (September 2022, Waste Regulation Section, Environmental Recycling and Resource Circulation Bureau, Ministry of the Environment: hereinafter also referred to as the "Guidelines"), and then identification and quantification analysis are performed using a liquid chromatograph-mass spectrometer (LC-MS / MS).

[0084] Through this analysis, each item of PFOS decomposition efficiency, decomposition and removal efficiency, PFOS emission concentration, and PFOA emission concentration is evaluated. Regarding the evaluation criteria, management target values are set based on the aforementioned Guidelines. In addition, in this example, the presence or absence of the generation of hydrogen fluoride and dioxins, which are harmful substances, is also appropriately evaluated.

[0085] Moreover, the PFOS- and PFOA-containing foam fire extinguishing agent has a very high viscosity, and in its original state, it may be difficult to discharge (inject or spray) from the injection nozzle of the discharge port (56). Therefore, in order to facilitate discharge inside the kiln end portion (45), the PFOS- and PFOA-containing foam fire extinguishing agent is diluted before discharge.

[0086] [·Test Equipment] As the test equipment, the cement clinker firing equipment configured as described above is used. The main specifications of the test equipment are shown in Table 1. Note that the installation location is in the northern part of Okinawa Prefecture.

[0087]

Table 1

[0088] [·Treatment Target (Test Sample)] In this example, a PFOS- and PFOA-containing foam fire extinguishing agent (PFOS concentration is about 6,000 mg / kg and PFOA concentration is about 60 mg / kg) is used as the test sample. Also, regarding the input amount of PFOS, it is set to 1,000 g / h (5,000 g / 5 h) considering the lower limit of analytical quantification.

[0089] [·Sampling Location of Sample] (Storage Tank: Test Sample) The test sample is directly sampled before being introduced into the test equipment for comparison before and after treatment. Specifically, for the sampling location, it is taken from the storage location before being introduced into the test equipment, that is, from the storage tank (51). The test sample is diluted to facilitate discharge inside the kiln end portion (45) as described above. Therefore, the diluted sample is sampled and evaluated as the test sample. (Rotary Kiln: Cement Clinker) Considering the residence time in the rotary kiln (40) (about 40 minutes) and the cooling time in the cooler device (43) (about 20 minutes), a sample is taken once at the time point 1 hour after the start of input of the test sample, and then a total of 4 times at 1-hour intervals, and the sample is taken at the discharge port of the cooler device (43). (Dust: Electrostatic Precipitation Ash) Considering the residence time from the rotary kiln (40) to the preheater (20) (the exhaust gas arrival time at the electrostatic precipitator is assumed to be about 10 - 15 minutes), a sample is taken once at the time point 1 hour after the start of input of the test sample, and then a total of 4 times at 1-hour intervals, and the sample is taken by the conveyor at the dust discharge port (56) of the electrostatic precipitator. (Raw material storage silo: Cement raw material) Considering the residence time from the preheater (20) to the rotary kiln (40) (assuming that the time for the electric dust collection ash to mix with the cement raw material is about 2 hours), samples are collected once at the time when 2 hours have elapsed since the start of the input of the test sample, and then a total of 4 times at 1-hour intervals at the outlet of the raw material storage silo. (Upper part of preheater: Exhaust gas) Considering the residence time from the rotary kiln (40) to the upper part of the preheater (20), continuous sampling for 4 hours for dioxin measurement is carried out starting from the time when 1 hour has elapsed after the start of the input of the test sample. For each of PFOS and PFOA, continuous sampling for 1 hour is carried out twice each. (Chimney: Exhaust gas) Considering the residence time of the exhaust gas from the rotary kiln (40) to the chimney, continuous sampling for 4 hours for dioxin measurement is carried out starting from the time when 1 hour has elapsed after the start of the input of the test sample. For each of PFOS and PFOA, continuous sampling for 1 hour is carried out twice each. (Industrial water: Water) Samples are collected from the outlet of the industrial water storage tank.

[0090] [·Test results] Samples are collected from each of the sampling locations and analyzed and evaluated in accordance with the above-mentioned guidelines. The evaluation results are sorted out and shown below.

[0091] (1) Both the decomposition efficiency and the decomposition and removal efficiency of PFOS achieved the target values. (2) The PFOS emission concentration was below the management target values for exhaust gas, cement clinker, and dust. (3) The evaluation of the hydrogen fluoride emission concentration was below the management target value of 5 mg / m 3 N. (4) The emission concentration of dioxins in the chimney exhaust gas was below the emission standard of 0.1 ng-TEQ / m 3 N according to the Special Measures Law on Dioxin Countermeasures. (5) PFOA decomposition efficiency and decomposition and removal efficiency Regarding PFOA, its decomposition efficiency and decomposition and removal efficiency were 99.9947% and 99.9986% respectively. (6) Evaluation of PFOA emission concentration The PFOA emission concentration was below the management target value for both exhaust gas, cement clinker, and dust.

[0092] As described above, according to this embodiment, by utilizing (diverting) the processing equipment (10) that has been operating in cement production, PFOS and PFOA can be decomposed (destroyed) in large quantities without generating harmful substances during the processing. It can be seen that through this embodiment (this confirmation test), the usefulness of the present invention has been confirmed.

[0093] <Finally> With the above, the description of one or more specific embodiments and one or more specific examples ends. However, the aspects of the present invention are not limited to these embodiments or examples, and can be appropriately modified, improved, etc.

Industrial Applicability

[0094] The present invention is useful as a processing equipment and processing method that can utilize (divert) the processing equipment that has been operating in cement production to decompose (destroy) PFOS and / or PFOA in large quantities without generating harmful substances during the processing.

Explanation of Signs

[0095] 10: Processing equipment 20: Preheater 21: Cyclone 22: Inlet 30: Calciner 40: Rotary kiln 41: Front part of the kiln 42: Kiln hood part 43: Cooler device 45: Rear part of the kiln 50: Supply part 51: Storage tank 52: Pressure pump 53: Pipe 55: Discharge pipe 56: Discharge port AM: Aqueous mixture CP: Intersection DC1: First exhaust duct DC2: Second exhaust duct DC3: Third exhaust duct DR1: First direction DR2: Second direction ST: Shoot

Claims

1. A preheater for preheating cement raw materials pulverized by a raw material mill, a kiln connected to the kiln tail portion of the preheater for firing the cement raw materials preheated by the preheater to produce clinker, a discharge pipe disposed in the kiln tail portion, having a discharge port protruding toward the inside of the kiln tail portion, and to which an aqueous mixture containing PFOS and / or PFOSA is supplied and the aqueous mixture is discharged from the discharge port toward the inside of the kiln tail portion, while producing the clinker, simultaneously discharging the aqueous mixture from the discharge port of the discharge pipe, a processing facility.

2. An exhaust duct erected along the vertical upward direction is connected to the kiln tail portion, exhaust gas generated in the kiln flows through the exhaust duct, the discharge pipe is disposed on the wall surface of the kiln tail portion on the side opposite to the main body portion of the kiln and on the exhaust duct side with reference to the main body portion of the kiln, the main body portion of the exhaust duct, and the intersection of the first direction which is the extending direction of the kiln and the second direction which is the extending direction of the exhaust duct. The processing facility according to Claim 1.

3. An exhaust duct erected along the vertical upward direction is connected to the kiln tail portion, exhaust gas generated in the kiln flows through the exhaust duct, the discharge port is offset and disposed closer to the side opposite to the main body portion of the kiln in the internal space of the kiln tail portion with reference to the main body portion of the kiln, the main body portion of the exhaust duct, and the intersection of the first direction which is the extending direction of the kiln and the second direction which is the extending direction of the exhaust duct. The processing facility according to Claim 1.

4. The central axis of the discharge direction of the discharge port is set to be inclined upward so as to face the main body side of the exhaust duct. The processing facility according to Claim 3.

5. The discharge pipe discharges the aqueous mixture radially from the discharge port. The processing facility according to Claim 4.

6. a storage tank for storing the aqueous mixture, a pressure pump connected to the discharge pipe for pumping and supplying the aqueous mixture in the storage tank, The processing facility according to Claim 1.

7. The pressure pump continuously supplies the aqueous mixture to the discharge pipe. The processing facility according to Claim 6.

8. A preheater for preheating cement raw materials pulverized by a raw material mill, A kiln in which the preheater is connected to the kiln tail portion and the cement raw material preheated by the preheater is fired to produce clinker, An exhaust duct connected to the kiln tail portion and erected vertically upward, A discharge pipe disposed at the lower end of the exhaust duct, with its discharge port protruding toward the inside of the exhaust duct, and an aqueous mixture containing PFOS and / or PFOSA is supplied to discharge the aqueous mixture from the discharge port toward the inside of the exhaust duct, While producing the clinker, simultaneously discharging the aqueous mixture from the discharge port of the discharge pipe, Processing equipment.

9. A preheating step of preheating a cement raw material pulverized by a raw material mill using a preheater, A firing step of firing the cement raw material preheated by the preheater to produce clinker using a kiln to which the preheater is connected at its kiln tail portion, A discharging step of supplying an aqueous mixture containing PFOS and / or PFOSA to a discharge pipe disposed at the kiln tail portion with its discharge port protruding toward the inside of the kiln tail portion and discharging the aqueous mixture from the discharge port toward the inside of the kiln tail portion using the discharge pipe, Performing the preheating step, the firing step, and the discharging step in parallel, Processing method.

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