JP2009240958A - Method and device for removing carbon monoxide and carbon dioxide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device which require no catalyst, and further, exhibit a high removal effect for carbon monoxide and carbon dioxide. <P>SOLUTION: A net 13 is provided in a vessel 10, and a calcium peroxide contact layer 14 is provided thereon. In the calcium peroxide contact layer 14, calcium peroxide powders are sprayed from a powder spraying apparatus 15, and at the same time, the sprinkling of water is carried out from a water spray bar 16, by which a slurry is formed. The slurry carries out the removal of carbon monoxide in a mix gas introduced from an introduction pipe 17 while moving gradually downward in the calcium peroxide contact layer 14. Thereby, carbon monoxide in the mix gas is oxygenized to turn carbon dioxide, further reacts to calcium hydroxide, and is absorbed as calcium carbonate. The slurry which has finished the removal of carbon monoxide drops to the bottom of the vessel 10, and further, is discharged outside the vessel 10 through a drainpipe 19. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and apparatus for removing carbon monoxide and carbon dioxide, and more particularly, to a method and apparatus for removing carbon monoxide and carbon dioxide using calcium peroxide in the presence of water.

  Conventionally, it is widely known that carbon monoxide is harmful to the human body. This carbon monoxide is inevitably included in combustibles, such as tobacco smoke, gasoline engine and diesel engine exhaust gas, and heating equipment, and is also included in indoor air using heating with carbon dioxide. It is also known to occur during a fire.

  Various developments have been made to remove such carbon monoxide. For example, in order to remove carbon monoxide contained in tobacco smoke, it has been studied to blend a metal oxide or metal carbonate, calcium peroxide, and a catalyst (Patent Document 1). In addition, the use of a superoxide or a peroxide together with a catalyst has been studied (Patent Document 2). Furthermore, oxidation of pollutants in exhaust gas using calcium peroxide in soil has been studied (Patent Document 3).

However, when oxidizing carbon monoxide using a metal oxide or metal carbonate and calcium peroxide, there is a problem that carbon monoxide cannot be oxidized without a catalyst. Further, when carbon monoxide is oxidized using superoxide or peroxide, there is the same problem that carbon monoxide cannot be oxidized without a catalyst. Further, when oxidizing using calcium peroxide in soil, there is a problem that oxidation to carbon monoxide is insufficient even though it is effective for oxidizing nitric oxide.
JP-T-2007-527223 (Claim 27) JP 2006-8492 A (Claim 4) JP-A-11-114371 (paragraph [0020])

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a method and an apparatus that do not require a catalyst and have a high effect of removing carbon monoxide and carbon dioxide. Is to provide.

  In the present invention, even if carbon monoxide is brought into contact with ordinary calcium peroxide or hydrogen peroxide water, oxidation of carbon monoxide does not occur unless a catalyst is added. The system was completed based on the discovery that the oxidation of carbon monoxide occurred without the addition of any catalyst.

  That is, the method for removing carbon monoxide and carbon dioxide of the present invention is characterized in that a mixed gas containing carbon monoxide and / or carbon dioxide is brought into contact with calcium peroxide in the presence of water.

  The carbon dioxide produced by the oxidation of carbon monoxide reacts with the calcium hydroxide produced by the reaction of calcium oxide produced by the oxidation of carbon monoxide and water together with the carbon dioxide originally present in the mixed gas. Will be absorbed as.

  Moreover, in the above, it is possible to supply water to calcium peroxide and to supply the calcium peroxide containing water with gas containing carbon monoxide and / or carbon dioxide.

  Here, in the above, it is preferable that 80 parts by weight or more of water is present with respect to 100 parts by weight of calcium peroxide. This is because if water is not added in an amount of 80 parts by weight or more, mixing of calcium peroxide and water becomes insufficient, and calcium peroxide does not form a slurry to form a slurry. This is probably because contact cannot be secured.

  Furthermore, in the above, it is also possible to humidify a gas containing carbon monoxide and / or carbon dioxide and bring the humidified mixed gas into contact with calcium peroxide.

  Here, in the above, the relative humidity of the humidified mixed gas is preferably in a range exceeding 60%. Here, when the mixed gas is humidified and brought into contact with calcium peroxide, the oxidation of carbon monoxide proceeds sufficiently even when the absolute amount of water is small compared to when water is added to calcium peroxide. To do. This is considered to be due to the fact that the reaction scheme differs between when the mixed gas is humidified and when water is added to calcium peroxide.

  The apparatus for removing carbon monoxide and carbon dioxide of the present invention removes carbon monoxide and carbon dioxide in a mixed gas by using a calcium peroxide contact layer containing calcium peroxide and water. A device for supplying calcium peroxide to the calcium peroxide contact layer; water supply means for supplying water to the calcium peroxide contact layer; and a mixed gas in the calcium peroxide contact layer. And a ventilation means for contact.

  Here, in the above, it is preferable that 80 parts by weight or more of water is supplied with respect to 100 parts by weight of calcium peroxide. This is because if water is not added in an amount of 80 parts by weight or more, mixing of calcium peroxide and water becomes insufficient, and calcium peroxide does not form a slurry to form a slurry. This is probably because contact cannot be secured.

  Moreover, the carbon monoxide and carbon dioxide removal apparatus of the present invention is a carbon monoxide and / or carbon dioxide that removes carbon monoxide and / or carbon dioxide in a mixed gas by a calcium peroxide contact layer containing calcium peroxide and water. An apparatus for removing carbon dioxide, the calcium peroxide supplying means for supplying calcium peroxide to the calcium peroxide contact layer, the humidifying means for humidifying the mixed gas, and the humidified mixture in the calcium peroxide contact layer And a ventilation means for contacting the gas.

  Here, in the above, the relative humidity of the humidified mixed gas is preferably in a range exceeding 60%. Also in the above case, when the mixed gas is humidified and brought into contact with calcium peroxide, carbon monoxide is sufficiently oxidized even when the absolute amount of water is small compared to when water is added to calcium peroxide. proceed. As described above, this is considered to be caused by the fact that the reaction scheme differs between when the mixed gas is humidified and when water is added to calcium peroxide.

  According to the method and apparatus for removing carbon monoxide and carbon dioxide of the present invention, the concentration of carbon monoxide and carbon dioxide in the mixed gas can be reduced. Moreover, since the mixed gas containing carbon monoxide and / or carbon dioxide is brought into contact with calcium peroxide in the presence of water, the removal of carbon monoxide and carbon dioxide can be performed very easily.

  With such a simple invention configuration, the present invention can be applied not only to removal of carbon monoxide and carbon dioxide from tobacco smoke, exhaust gas of gasoline engines and diesel engines, but also as a mask at the time of fire. In addition, by applying to the walls of buildings, etc., the function of removing carbon monoxide and carbon dioxide can be developed just by splashing water on the sprinkler. , Prevent carbon monoxide damage and carbon dioxide suffocation.

  Embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.

(Removal test of carbon monoxide in cigarette smoke ... hydrated to calcium peroxide)
First, a removal test of carbon monoxide and carbon dioxide contained in tobacco smoke was performed. In a glass water tank of about 20 L, a beaker containing 10 g of calcium peroxide serving as a calcium peroxide contact layer and 250 mL of water was installed together with a stirrer. Moreover, the air pump for introduce | transducing and making the air in a water tank contact the calcium peroxide contact layer in a beaker was also installed in the glass water tank. Further, the tank was filled with tobacco smoke and completely sealed. Next, the test was started by starting stirring in the beaker with a stirrer and starting circulation of air containing tobacco smoke in the water tank by an air pump.

Changes in CO concentration, temperature, humidity and CO ₂ concentration from the start of the test are shown in FIG. As can be seen from FIG. 1, it can be seen that about 80% of the initial concentration of carbon monoxide and carbon dioxide is removed in about 3 hours.

(Removal test of carbon monoxide in diesel engine exhaust gas ... Hydrohydrate to calcium peroxide)
Next, a removal test of carbon monoxide contained in the exhaust gas of the diesel engine was performed. First, 10 g of calcium peroxide, 2 g of glass beads for preventing calcium peroxide from forming a lump, and 50 mL of water were placed in a test plastic bag. About 1 L of exhaust gas from a diesel engine collected in advance in a collection plastic bag was sealed in this test plastic bag. Next, this test plastic bag was shaken for 10 minutes, and exhaust gas, calcium peroxide, and water were sufficiently brought into contact with each other.

  As a result, the carbon monoxide concentration of the exhaust gas before being introduced into the test plastic bag was about 75 ppm, whereas the carbon monoxide concentration after the test was about 15 ppm, and about 80% of carbon monoxide was removed. You can see that

(Carbon monoxide and carbon dioxide removal equipment)
FIG. 2 is a schematic view of a carbon monoxide and carbon dioxide removing apparatus according to an embodiment of the present invention. The removal device of the present embodiment continuously removes carbon monoxide and carbon dioxide from a mixed gas such as exhaust gas, a main body container 10, a water tank 11 for storing water, and calcium peroxide. And a powder tank 12 for storing the powder. A net 13 is provided at a substantially central portion in the vertical direction in the main body container 10, and a breathable and liquid-permeable material such as carbonized cotton, metal fiber, and glass fiber is placed on the net 13. Then, as described later, calcium peroxide powder and water are supplied to form the calcium peroxide contact layer 14.

  Further, in the main body container 10, a powder spraying device 15 for spraying the calcium peroxide powder in the powder tank 12 on the calcium peroxide contact layer 14, and the peroxide on the calcium peroxide contact layer 14. A watering pipe 16 for spraying water on the calcium powder is provided.

  Further, an introduction pipe 17 for introducing a mixed gas such as exhaust gas containing carbon monoxide and carbon dioxide is provided at the lower part of the main body container 10, and the mixed gas introduced from the introduction pipe 17 passes through the net 13. Thus, it comes into contact with the calcium peroxide contact layer 14. A discharge pipe 18 for discharging the mixed gas after removing carbon monoxide and carbon dioxide is provided on the upper part of the main body container 10. In addition, a drain pipe 19 for discharging a slurry made of calcium carbonate, water and the like after removing carbon monoxide is provided at the lowermost part of the main body container 10.

  The carbon monoxide and carbon dioxide removing device of the present embodiment configured as described above is used as follows. First, the powder spraying device 15 starts spraying calcium peroxide powder on the calcium peroxide contact layer 14. At the same time, water sprinkling is started from the water spray pipe 16. Thereby, a slurry composed of calcium peroxide and water is formed on the calcium peroxide contact layer 14. This slurry gradually moves downward in the calcium peroxide contact layer 14.

  Next, the introduction of the mixed gas containing carbon monoxide and carbon dioxide into the main body container 10 from the introduction pipe 17 is started. The mixed gas introduced into the main body container 10 comes into contact with the slurry composed of calcium peroxide and water when passing through the calcium peroxide contact layer 14. Thereby, the carbon monoxide in the mixed gas is oxidized to carbon dioxide. Next, the generated carbon dioxide and the carbon dioxide originally contained in the mixed gas are absorbed by the reaction with calcium oxide generated by the reaction of calcium oxide generated by the oxidation of carbon monoxide and water, and calcium carbonate and Become.

  The mixed gas after the removal of carbon monoxide and carbon dioxide is discharged from the upper part of the main body container 10 through the discharge pipe 18. On the other hand, the slurry after the removal of carbon monoxide and carbon dioxide falls from the calcium peroxide contact layer 14 to the bottom of the main body container 10 and is further discharged to the outside of the main body container 10 through the drain pipe 19. Become.

  In the present embodiment, water is supplied to the calcium peroxide on the calcium peroxide contact layer 14, but in other embodiments, the water tank 11 and the water spray pipe 16 are not provided, and these are replaced. A humidifier that humidifies the mixed gas may be provided, and the humidified mixed gas may be brought into contact with the calcium peroxide contact layer 14. Examples of the humidifier for the mixed gas in this case include a heating humidifier and an ultrasonic humidifier. In the case of using a heating humidifier, the temperature of the mixed gas is increased, so that the reaction between carbon monoxide and calcium peroxide can be promoted.

  FIG. 3 shows an outline of a carbon monoxide and carbon dioxide removing apparatus according to another embodiment of the present invention. The carbon monoxide and carbon dioxide removal device of this embodiment includes an exhaust gas treatment box 25 that houses a large number of pulleys 24, and a pulley 31 and a drive pulley 32 that are disposed outside the exhaust gas treatment box 25. A belt 23 is wound around the pulleys 24 and 31 and the drive pulley 32. In the present embodiment, a powder tank 12 that supplies calcium peroxide powder onto the belt 23 outside the exhaust gas treatment box 25 and a water tank 11 that supplies water to the calcium peroxide on the belt 23 are provided. ing. In this embodiment, the calcium peroxide and water layer on the belt is a calcium peroxide contact layer. The calcium peroxide contact layer on the belt 23 moves in the exhaust gas treatment box 25 by driving the drive pulley 32.

  In the present embodiment, an introduction pipe 17 for introducing a mixed gas such as an exhaust gas containing carbon monoxide and carbon dioxide is provided below the exhaust gas treatment box 25. In addition, an exhaust pipe 18 for discharging the mixed gas after removing carbon monoxide and carbon dioxide is provided on the upper part of the exhaust gas treatment box 25. Further, at the bottom of the main body container 10, a water tank 22 for supplying water for removing slurry made of calcium carbonate, water and the like after removing carbon monoxide from the belt 23, a brush 28 for scraping off the slurry, and A storage tank 29 for storing the dropped slurry is provided. The storage tank 29 is provided with a supernatant drain pipe 30 for discharging the supernatant and a drain pipe 33 for discharging the precipitate.

  The carbon monoxide and carbon dioxide removing device of the present embodiment configured as described above is used as follows. First, spraying of calcium peroxide powder from the powder tank 12 onto the belt 23 is started. At the same time, water sprinkling is started from the water tank 11 to be supplied. As a result, a calcium peroxide contact layer made of a slurry of calcium peroxide and water is formed on and adhered to the belt 23. The slurry moves downward in the exhaust gas treatment box 25 while being conveyed by the belt 23.

  Next, the introduction of the mixed gas containing carbon monoxide and carbon dioxide into the exhaust gas treatment box 25 from the introduction pipe 17 is started. The mixed gas introduced into the exhaust gas treatment box 25 comes into contact with the calcium peroxide contact layer on the belt 23, and the carbon monoxide in the mixed gas is oxidized to carbon dioxide. Next, the generated carbon dioxide and the carbon dioxide originally contained in the mixed gas are absorbed by the reaction with calcium oxide generated by the reaction of calcium oxide generated by the oxidation of carbon monoxide and water, and calcium carbonate and Become.

  The mixed gas after the removal of carbon monoxide and carbon dioxide is discharged from the upper part of the exhaust gas treatment box 25 through the discharge pipe 18. On the other hand, the slurry from which the removal of carbon monoxide and carbon dioxide has been removed from the belt 23 by the water spray from the water tank 22 supplied from the exhaust gas treatment box 25 and the action of the brush 28 being scraped off is stored in the storage tank 29. Stored inside.

  As described above, moisture is required for activation of the oxidation action of calcium peroxide. However, when carbon monoxide is oxidized below the freezing temperature, that is, below 0 ° C., the oxidation action will not be small. It is. Therefore, under low temperature conditions, it is necessary to oxidize carbon monoxide under heating.

  Moreover, it seems that the reaction via water hardly occurs at a temperature at which water boils, that is, at 100 ° C. or higher. In particular, since the temperature of the exhaust gas from the internal combustion engine is high, it is necessary to lower the temperature when drawing directly. Therefore, air cooling is required, such as lengthening the exhaust gas introduction pipe.

  Calcium peroxide is hardly soluble in water, and when water is added to a certain amount of calcium peroxide, the amount of calcium peroxide dissolved in the added water becomes constant. If the suspension is used for removing carbon monoxide as it is, dissolution of calcium peroxide in water is inhibited by calcium carbonate finally produced, and the oxidation reaction of carbon monoxide gradually becomes worse. In that case, all of the calcium peroxide must be discarded after the reaction, even though only a small portion of calcium peroxide is effectively used.

  In order to solve this point, when calcium peroxide is suspended, it is allowed to stand to precipitate insoluble calcium peroxide, and only the aqueous solution of calcium peroxide in the supernatant is used for the carbon monoxide reaction. If the supernatant is discarded after the reaction, it is possible to prevent calcium peroxide from being used more than necessary. If the supernatant is allowed to stand after the reaction to remove calcium carbonate as a precipitate, the water can be recycled again.

(Carbon monoxide removal test from mixed gas containing carbon monoxide: humidifying the mixed gas)
Experiments were conducted on the removal ability of carbon monoxide by changing the amount of water vapor with respect to the gas mixture containing carbon monoxide. When water is put into a 20 L sealed container containing carbon monoxide (about 120 ppm) and published, the humidity gradually increases. 50 mL was collected over time and passed through a column containing 0.1 g of calcium peroxide to examine the degree of carbon monoxide removal. The room temperature during the experiment was 22 ° C. The experimental results are shown in FIG. As shown in the figure, when the humidity exceeded 60% at room temperature, the effect of removing carbon monoxide appeared, and the concentration of carbon monoxide rapidly decreased. From this result, it can be seen that carbon monoxide removal starts when the humidity exceeds 60%.

(Removal test of carbon monoxide in exhaust gas ... Effect of water content on calcium peroxide)
1 g of calcium peroxide was put into a 50 mL disposable syringe, water was added, and 50 mL of exhaust gas was sucked and sealed. After stirring this with a shaker for 5 minutes (200 rpm), the exhaust gas was recovered and the carbon monoxide concentration was measured. The concentration change when the amount of water was changed is shown in FIG.

  The removal effect of carbon monoxide appeared when the amount of water added was 0.8 mL or more. If water is not about 0.8 mL, this is considered to be because the used calcium peroxide was not completely wetted and became a dumpling, resulting in poor gas contact. If water is present in an amount of 0.8 mL or more, it is considered that the whole calcium peroxide becomes wet and becomes mud, which facilitates mixing with the exhaust gas. Further, when 2 mL of water was present, the whole became a slurry, and stirring was further facilitated. From this result, it is understood that the amount of water effective for removing carbon monoxide is 80 parts by weight or more with respect to 100 parts by weight of added calcium peroxide.

  According to the carbon monoxide and carbon dioxide removal method and apparatus of the present invention, carbon monoxide and carbon dioxide can be removed very easily. It can also be used in fields such as environmental conservation industries related to exhaust gas from diesel engines, and disaster prevention industries that protect themselves from carbon monoxide in the event of a fire.

It is a figure showing the result of the removal test of carbon monoxide and carbon dioxide contained in tobacco smoke. It is the schematic of the carbon monoxide and carbon dioxide removal apparatus which concerns on one Embodiment of this invention. It is the schematic of the carbon monoxide and carbon dioxide removal apparatus which concerns on other embodiment of this invention. It is a figure which shows the carbon monoxide removal effect at the time of humidifying the gas mixture containing carbon monoxide. It is a figure which shows the removal effect of carbon monoxide at the time of changing the amount of water to calcium peroxide.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Main body container 11 Water tank 12 Powder tank 13 Net 14 Calcium peroxide contact layer 15 Powder spreader 16 Sprinkling pipe 17 Introducing pipe 18 Discharge pipe 19 Drain pipe 24 Pulley 25 Exhaust gas treatment box 31 Pulley 32 Drive pulley 22 Water tank 23 Belt 28 Brush 29 Reservoir 30 Supernatant drain 33 Drain pipe

Claims (9)

  A method for removing carbon monoxide and carbon dioxide, comprising bringing a mixed gas containing carbon monoxide and / or carbon dioxide into contact with calcium peroxide in the presence of water.   2. The carbon monoxide according to claim 1, wherein water is supplied to calcium peroxide, and a gas containing carbon monoxide and / or carbon dioxide is supplied to and contacted with the calcium peroxide containing water. And a method for removing carbon dioxide.   The method for removing carbon monoxide and carbon dioxide according to claim 1, wherein 80 parts by weight or more of water is present with respect to 100 parts by weight of calcium peroxide.   The method for removing carbon monoxide and carbon dioxide according to claim 1, wherein a gas containing carbon monoxide and / or carbon dioxide is humidified, and the humidified mixed gas is brought into contact with calcium peroxide.   The method for removing carbon monoxide and carbon dioxide according to claim 4, wherein the humidified mixed gas has a relative humidity in a range exceeding 60%. An apparatus for removing carbon monoxide and carbon dioxide, which removes carbon monoxide and carbon dioxide in a mixed gas by a calcium peroxide contact layer containing calcium peroxide and water,
Calcium peroxide supply means for supplying calcium peroxide to the calcium peroxide contact layer;
Water supply means for supplying water to the calcium peroxide contact layer;
An apparatus for removing carbon monoxide and carbon dioxide, comprising a ventilation means for bringing a mixed gas into contact with the calcium peroxide contact layer. A carbon monoxide and carbon dioxide removal device for removing carbon monoxide and / or carbon dioxide in a mixed gas by a calcium peroxide contact layer containing calcium peroxide and water,
Calcium peroxide supply means for supplying calcium peroxide to the calcium peroxide contact layer;
Humidifying means for humidifying the mixed gas;
An apparatus for removing carbon monoxide and carbon dioxide, comprising a ventilation means for bringing the humidified mixed gas into contact with the calcium peroxide contact layer.   The carbon monoxide and carbon dioxide removal apparatus according to claim 6, wherein 80 parts by weight or more of water is supplied with respect to 100 parts by weight of calcium peroxide.   The apparatus for removing carbon monoxide and carbon dioxide, wherein the humidified mixed gas has a relative humidity in a range exceeding 60%.

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