JP2011240322A - Carbon dioxide gas recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized carbon dioxide gas recovery device which can easily recover a carbon dioxide gas discharged from a steel plant or the like at low cost.SOLUTION: The carbon dioxide gas recovery device is equipped with a roots pump 3 which can freely rotate a pair of roots rotors 26 accommodated in a pump casing 4 by a drive motor 38, has a collision member 50 which makes an air introduction port 46 collide with sucked water at a pipe conduit communicating with a suction pipe 45, sucks water from the suction pipe 45 by the operation of the roots pump 3 and generates a large volume of bubbles by making water mixed with air taken in from the air introduction port 46 collide with the collision member 50, makes fine the bubbles by compression action by the roots pump 3, and dissolves the carbon dioxide gas by discharging the water containing the fined bubbles from a discharging pipe 55 into the water of a purification tank, a river or the like.

Description

The present invention recovers carbon dioxide (CO ₂ ) gas discharged from a power plant, ironworks, incinerator, etc. by mixing it with water sucked by a roots pump, releasing it into water and dissolving it. The present invention relates to a gas recovery device.

  Carbon dioxide gas, which is considered to be a cause of global warming, is often taken up at recent diplomatic sites and international conferences. In developed countries that consume large amounts of fossil fuels, how to achieve greenhouse gas emission reduction and emission control targets determined by the Kyoto Protocol is a major issue.

  Patent Document 1 includes an apparatus for separating and recovering carbon dioxide discharged from a steel plant and the like, and an apparatus for fixing the carbon dioxide recovered by the apparatus in the ground or in the sea, and separating and recovering carbon dioxide. Uses carbon dioxide to absorb carbon dioxide from blast furnace gas with chemical absorption liquid, and separates carbon dioxide from chemical absorption liquid that has absorbed carbon dioxide using a heat source for chemical absorption liquid regeneration to regenerate the chemical absorption liquid. Disclosed is a carbon dioxide separation and recovery device equipped with a facility for this purpose.

In Patent Document 2, since the low concentration of carbon dioxide is electrochemically enriched and separated by using a molten carbonate, sulfide contained in the exhaust gas, chloride, impurities such as NO _X Disclosed is a carbon dioxide concentration method and apparatus for recovering high-purity and high-concentration carbon dioxide that does not contain water.

  In the conventional apparatus for separating and recovering and fixing carbon dioxide and the carbon dioxide concentrating apparatus, it is considered that all of them are large-scale facilities and the equipment cost is increased.

Japanese Patent No. 4231735 Japanese Patent No. 4385424

  An object of the present invention is to provide a small-sized carbon dioxide gas recovery device that can easily recover carbon dioxide gas discharged from a power plant, an ironworks, or the like at low cost.

In order to achieve the above object, the invention described in claim 1 is a carbon dioxide gas recovery device that recovers carbon dioxide gas generated during combustion of fossil fuel,
A roots pump in which a pair of roots rotors housed in a pump casing provided with a suction port and a discharge port are rotatably provided by a drive motor, a suction pipe connected to the suction port, and a discharge connected to the discharge port A pipe that communicates with the suction pipe is provided with a carbon dioxide gas inlet and a collision member that collides the sucked water with the carbon dioxide gas, and the water is discharged from the suction pipe by the operation of the roots pump. A large amount of bubbles are generated by colliding water mixed with carbon dioxide gas taken in from the inlet and colliding with the collision member, and the bubbles are refined by the compression action by the Roots pump. The carbon dioxide gas is dissolved in the water by discharging water containing bubbles of the carbon dioxide gas from the discharge pipe into the water. It is.

In order to achieve the same object, the invention described in claim 2 is a carbon dioxide gas recovery device that recovers carbon dioxide gas generated during combustion of fossil fuel,
A roots pump in which a pair of roots rotors housed in a pump casing provided with a suction port and a discharge port are rotatably provided by a drive motor, a suction pipe connected to the suction port, and a discharge connected to the discharge port A pipe, and an inlet for carbon dioxide gas is provided in the suction pipe, and bubbles of carbon dioxide gas mixed in water sucked from the suction pipe by the operation of the roots pump are refined by the compression action of the roots pump, The carbon dioxide gas is dissolved in the water by discharging the water containing the refined bubbles from the discharge pipe into the water.

In order to achieve the same object, the invention described in claim 3 is a carbon dioxide gas recovery device that recovers carbon dioxide gas generated during combustion of fossil fuel,
A roots pump in which a pair of roots rotors housed in a pump casing provided with a suction port and a discharge port are rotatably provided by a drive motor, a suction pipe connected to the suction port, and a discharge connected to the discharge port A water pump provided to connect the discharge side to the suction side of the suction pipe and the suction pipe. The suction pipe has a built-in ejector and a carbon dioxide gas inlet, and the water pump and the roots pump The carbon dioxide gas bubbles mixed in the water sucked from the suction pipe by the linked operation are refined by the compression action of the roots pump, and the water containing the refined bubbles is discharged into the water from the discharge pipe. It is characterized by dissolving carbon gas in water.

  In order to achieve the same object, the invention described in claim 4 is the carbon dioxide gas recovery device according to any one of claims 1 to 3, wherein the outlet side of the discharge pipe and the suction side of the suction pipe are predetermined. Each of the tanks is connected to a tank having a capacity, and water in the tank is circulated and supplied to the roots pump.

  By circulating and supplying water stored in a tank attached to the carbon dioxide gas recovery device to the roots pump, it is possible to save water in which carbon dioxide gas is dissolved.

  In order to achieve the same object, the invention described in claim 5 is the carbon dioxide gas recovery device according to any one of claims 1 to 4, wherein the roots rotor is a two-leaf type roots rotor. It is.

  When a two-leaf root rotor is employed, the self-priming capability is higher than that of a three-leaf root rotor, and the amount of suction per one rotation is large. Moreover, the operation | work which assembles a 2 leaf type roots rotor to a pump casing has the advantage that it can carry out easily compared with the case of a 3 leaf type roots rotor.

(Invention of Claim 1)
This carbon dioxide gas recovery device generates a large amount of bubbles by colliding water mixed with carbon dioxide gas with a collision member by the operation of the roots pump, and further refines the bubbles by the compression action of the roots pump. By discharging water containing bubbles of carbon gas into the water, the carbon dioxide gas can be efficiently dissolved in the water. In addition, this apparatus is small in size and inexpensive in equipment cost, and can easily recover carbon dioxide gas discharged from a power plant, a steel mill or the like at low cost.

(Invention of Claim 2)
This carbon dioxide gas recovery device refines the carbon dioxide gas bubbles mixed in the water sucked by the operation of the roots pump by the compressing action of the roots pump, and releases the carbon dioxide gas by releasing the water containing the bubbles into the water. It can be dissolved efficiently in water.

(Invention of Claim 3)
This carbon dioxide gas recovery device refines the bubbles of carbon dioxide gas mixed in the water sucked by the cooperative operation of the water pump and the roots pump by the compression action of the roots pump, and the water containing the refined bubbles is submerged in the water. The carbon dioxide gas can be efficiently dissolved in water by releasing it into the water.

Carbon dioxide gas recovery apparatus according to the first embodiment of the present invention Roots pump internal structure diagram Roots pump partially broken side view Illustration of bubble generation tube Experimental apparatus using carbon dioxide gas recovery apparatus according to the first embodiment The graph which shows the measurement result of the carbon dioxide gas dissolved amount of Experiment 1 The graph which shows the measurement result of the carbon dioxide gas dissolved amount of experiment 2 The graph which shows the measurement result of the carbon dioxide gas dissolved amount of Experiment 3 (1) Graph (2) showing measurement results of dissolved amount of carbon dioxide gas in Experiment 3 Carbon dioxide gas recovery apparatus according to the second embodiment of the present invention Recovery system using carbon dioxide gas recovery apparatus according to the second embodiment Carbon dioxide gas recovery apparatus according to the third embodiment of the present invention

  The best mode of the present invention will be described below with reference to the drawings.

Example 1
The carbon dioxide gas recovery device C according to the first embodiment of the present invention releases carbon dioxide gas into water by discharging the carbon dioxide gas discharged from a power plant, ironworks, etc. into water such as rivers as fine bubbles. It has a function to dissolve efficiently. This apparatus includes a Roots pump 3, a suction pipe 45 connected to the suction port 5, and a discharge pipe 55 connected to the discharge port 6.

  As shown in FIG. 1, a roots pump 3 and a drive motor 38 are installed on the machine base 1 of the carbon dioxide gas recovery apparatus C. As shown in FIG. 2, the Roots pump 3 has a rotor casing in which a suction port 8 is provided obliquely upward and a discharge port 9 is provided obliquely downward in a pump casing 4 provided with a suction port 5 and a discharge port 6. 7 is inclined at 45 degrees. The upper corner 7 a of the suction port 8 of the rotor casing 7 and the top 4 a on the suction port 5 side of the pump casing 4 are connected by a wall 10. Further, a concave arc wall 11 is integrally formed laterally from the lower corner portion 7b of the discharge port portion 9, and a substantially middle portion of the concave arc wall 11 and the bottom portion 4b of the pump casing 4 are connected by a vertical wall 12. Yes. Reference numeral 13 denotes a bypass hole provided in the vertical wall 12. This bypass hole 13 is provided so that the water in the pump casing 4 can be circulated.

  14 and 14 are drain holes provided in the peripheral wall of the pump casing 4, and 15 is a water supply hole provided in the top portion 4 a of the pump casing 4. A cap 17 is screwed into one drain hole 14, and a cap 21 is screwed into the water supply hole 15. The cap 18 that is screwed into the other drain hole 14 is provided with a rod 19 that protrudes into the bypass hole 13 at the center.

A flange fitting 23 for piping is attached to the suction port 5 via a check valve 22. Similarly, a flange fitting 24 is attached to the discharge port 6.

  The rotor casing 7 accommodates a pair of two-leaf root rotors 26. As shown in FIG. 3, the rotor shaft 27 of the Roots rotor 26 is provided so as to be freely supported by bearings 32, 32 attached to housings 30, 31 fixed to both sides of the pump casing 4. A pulley 34 is attached to one end of the lower rotor shaft 27 protruding from the housing 30, and the pulley 34 is rotationally driven by a drive motor device 38 via a transmission belt 39. A timing gear 35 is fixed to the other end of the rotor shaft 27, and the timing gears 35 are engaged with each other. Reference numeral 36 denotes a gear cover attached to the opening of the housing 31.

  The housings 30 and 31 are provided with a stuffing box 33 in which a well-known mechanical seal is accommodated behind a bearing 32 that supports the rotor shaft 27.

About the roots rotor 26, the outer side of the metal core part 26b formed except the rotor shaft | axis 27 is given the lining process with the polyurethane rubber material (or nitrile rubber material).

In this embodiment, the two-leaf root rotor 26 is employed, but the present invention is not limited to this, and a three-leaf or four-leaf multi-leaf root rotor can also be employed.

  As shown in FIG. 1, a bubble generating tube 46 is connected to the suction side of the suction tube 45 of the Roots pump 3. Reference numeral 47 denotes a collision member for generating bubbles built in the large diameter portion 46a of the bubble generating tube 46. As shown in FIG. 4, the collision member 47 is configured such that a circular plate 47c is integrally provided at the upper ends of four legs 47b extending upward from a ring 47a placed on the inner bottom of the large diameter portion 46a.

  The pipe 50 connected to the inlet side of the bubble generating pipe 46 is provided with a carbon dioxide gas inlet 51. An on-off valve 52 is attached to the introduction pipe 50 b branched from the main body 50 a of the pipe 50.

  As described above, when the roots pump 3 is operated, water is sucked from the suction pipe 45 and water mixed with carbon dioxide gas taken in by the ejector action from the carbon dioxide gas inlet 51 is caused to collide with the collision member 47 to thereby generate a large amount of bubbles. The carbon dioxide gas is submerged into the water by generating the microbubbles by the compression action of the Roots pump 3 and discharging the water containing the micronized carbon dioxide gas bubbles from the discharge pipe 55 into the water such as a river. A carbon dioxide gas recovery apparatus C according to the first embodiment of the present invention that dissolves efficiently is configured.

  In the carbon dioxide gas recovery apparatus C according to the present invention, the outlet side of the discharge pipe 55 and the suction side of the suction pipe 45 are connected to a tank (not shown) having a predetermined capacity, respectively, and the water in the tank is supplied to the roots pump 3. It is also possible to configure so as to circulate the gas. If there is no river or reservoir near the place where the present apparatus is installed, the desired effect can be obtained by installing a tank.

(Experiment 1 and Experiment 2)
About the carbon dioxide gas recovery apparatus C according to the first embodiment of the present invention, water containing bubbles of carbon dioxide gas discharged from the apparatus is discharged into the water in the tank by the experimental apparatus shown in FIG. An experiment was conducted to measure the amount of carbon dioxide gas dissolved and the change in the amount of dissolved gas with time. The experimental results are shown in the graph of FIG.
(Experimental conditions)
Diameter of two-leaf root pump: 50mm
Rotational speed: 650rpm
Motor output: 1.5Kw
Suction pressure: -20kPa
Discharge pressure: 40kPa
Pump suction amount: 200 l / min
Carbon dioxide gas concentration in Experiment 1: 30%
(Amount of carbon dioxide gas: 15 liter / min, amount of air: 35 liter / min)
Carbon dioxide gas concentration in Experiment 2: 100%
(Amount of carbon dioxide gas: 5 liter / min, amount of air: 6 liter / min)
Tank volume: 2.9m ³
Water temperature: 25 ° C
(Measuring instrument)
Carbon dioxide gas dissolved amount measuring instrument: Toko Chemical Laboratory Ti-9004

  As a result of Experiment 1, as shown in the graph of FIG. 6, when the operation time of the recovery device C has passed 80 minutes, the dissolved amount of carbon dioxide gas, in other words, the carbon dioxide concentration is about 570 (mg / liter), and a large amount of carbon dioxide It was confirmed that carbon gas was dissolved. Moreover, the density | concentration of the carbon dioxide gas became about 380 (mg / liter) after five days progress, and it was confirmed that the carbon dioxide gas is dissolved in water effectively.

  For Experiment 2, using the gas cylinder, 100% concentration carbon dioxide gas was released into water for 90 minutes, then the supply of carbon dioxide gas was stopped for 120 minutes, and 6 liters of air was allowed to flow in. Changes in the amount of carbon gas dissolved were measured. The experimental results are shown in the graph of FIG.

  As a result of Experiment 2, the concentration of carbon dioxide gas became 200 (mg / liter) after about 200 minutes and reached the virtual saturation point.

(Experiment 3)
Filled with water to a tank volume 1.0 m ^3, the pump suction amount: while circulating the water in the tank at 200 l / min, a 20 ° C. carbon dioxide gas was supplied at 25 l / min, tank for 60 minutes The change of the dissolved amount of carbon dioxide gas was measured.

  Similarly, while circulating water in the tank at a pump suction amount of 200 liters / min, about 100 ° C. carbon dioxide gas heated by a heater is supplied at 25 liters / min, and the carbon dioxide in the tanks for 60 minutes. The change in gas dissolved amount was measured. Subsequently, the supply of carbon dioxide gas was stopped, and the change in the dissolved amount of carbon dioxide gas in the tank was measured over 7 days. The results of these experiments are shown in the graphs of FIGS.

  As a result of Experiment 3, the concentration of carbon dioxide gas at 20 ° C. is about 1750 (mg / liter) after 60 minutes as shown in the graph of FIG. 8, and a large amount of carbon dioxide gas is dissolved in water. Was confirmed. And even after 7 days passed, it was about 1100 (mg / liter), and it was confirmed that carbon dioxide gas was effectively dissolved in water.

  On the other hand, as shown in the graph of FIG. 9, the concentration of carbon dioxide gas at 100 ° C. is about 2700 (mg / liter) after 60 minutes, and it is confirmed that a large amount of carbon dioxide gas is dissolved in water. It was. And even after 7 days, it was about 1900 (mg / liter), and it was confirmed that carbon dioxide gas was dissolved effectively in water.

(Example 2)
The carbon dioxide gas recovery device D according to the second embodiment of the present invention does not employ the bubble generating pipe 46 in the carbon dioxide gas recovery device C according to the first embodiment described above, and the carbon dioxide gas is provided in the suction pipe 60. The inlet 61 is provided. About the structure of other than that, it is set as the structure similar to the carbon dioxide gas recovery apparatus C which concerns on 1st Example. Therefore, about the same component as it, the code | symbol used for description of the apparatus C is described in drawing, and description is abbreviate | omitted.

  Specifically, as shown in FIG. 10, an inlet pipe 60 b provided with a carbon dioxide gas inlet 61 is integrally formed in the inlet pipe 60 so as to branch in an orthogonal shape. 62 is an on-off valve attached to the introduction pipe 60b.

  Accordingly, the bubbles of carbon dioxide gas mixed in the water sucked from the suction pipe 60 by the operation of the roots pump 3 are refined by the compression action of the roots pump 3, and the water containing the refined bubbles is discharged from the discharge pipe 55. A carbon dioxide gas recovery device D according to the second embodiment of the present invention is configured to dissolve carbon dioxide gas in water by releasing it into water.

The carbon dioxide gas recovery device D according to the second embodiment is suitable when the pump suction amount is 200 liters / min or more, and has a feature that carbon dioxide gas is easily dissolved in water sucked from the suction pipe 60.
Incidentally, the carbon dioxide gas recovery apparatus C according to the first embodiment is suitable when the pump suction amount is 200 liters / min or less.

An example of a recovery system using the carbon dioxide gas recovery device D according to the second embodiment is shown in FIG.
In the figure, the tip of the second suction pipe 63 connected to the suction pipe 60 of the carbon dioxide gas recovery device D is installed in a water tank 71 in which water such as seawater is stored. Reference numeral 64 denotes a strainer attached to the second suction pipe 63, and reference numeral 72 denotes a supply pipe for supplying water to the water tank 71. The introduction pipe 60b of the apparatus D is connected with a pipe 65 for connecting to a tank 75 that temporarily stores carbon dioxide gas supplied from a power plant, an ironworks, or the like that is a carbon dioxide gas generation source. Reference numeral 67 denotes a second discharge pipe connected to the discharge pipe 55 of the apparatus D. 77 is a water tank for dissolving the carbon dioxide gas provided with the first chamber 77a, the second chamber 77b, and the third chamber 77c. 78 is a supply pipe for supplying water to the water tank 77, and 79 is a discharge port.

  In addition, although the said water tank 77 is provided with three chambers, it can be set as the structure of only one chamber. Further, it is possible to directly discharge water containing carbon dioxide gas from the second discharge pipe 67 to the sea or river without installing the water tank 77.

(Example 3)
The carbon dioxide gas recovery device E according to the third embodiment of the present invention does not employ the bubble generation tube 46 in the carbon dioxide gas recovery device C according to the first embodiment described above, and is disposed on the suction side of the suction tube 80. A discharge port of a separately installed water pump 86 is connected and a carbon dioxide gas inlet 81 is provided. About the structure of other than that, it is set as the structure similar to the carbon dioxide gas recovery apparatus C which concerns on 1st Example. Therefore, about the same component as it, the code | symbol used for description of the apparatus C is described in drawing, and description is abbreviate | omitted.

  As shown in FIG. 12, the suction side 80a of the suction pipe 80 of the apparatus E is formed in a tapered shape that is reduced in diameter toward the downstream side, and incorporates a similar tapered ejector 83 therein. A carbon dioxide gas inlet 81 is provided at a side position of the ejector 83. An introduction pipe 80 b is connected to the carbon dioxide gas introduction port 81. 84 is an on-off valve attached to the introduction pipe 80b.

  Thus, the roots pump 3 compresses the bubbles of carbon dioxide gas supplied from the water pump 86 by the cooperative operation of the water pump 86 and the roots pump 3 and smoothly mixed in the water sucked by the ejector 83 with the flow velocity increased. A carbon dioxide gas recovery device E according to the third embodiment of the present invention is constructed in which carbon dioxide gas is dissolved in water by making it fine and discharging the water containing the refined bubbles into the water from the discharge pipe 55. .

  In addition, about a water pump, it is preferable to employ | adopt a roots pump or a vortex pump. Further, the pump suction amount is set to 50 to 80% of the suction amount of the roots pump 3 of the carbon dioxide gas recovery device E.

  In the carbon dioxide gas recovery device C according to the first embodiment of the present invention, the amount of carbon dioxide gas sucked from the introduction pipe 50b is a maximum value of 40% with respect to the amount of water sucked. Moreover, in the case of the carbon dioxide gas recovery device E according to the third embodiment, the ratio is a value of 40 to 80%.

C: Carbon dioxide gas recovery device 3 according to the first embodiment of the present invention ... Roots pump 4 ... Pump casing 5 ... Suction port 6 ... Discharge port 26 ... Two-leaf root rotor 38 ... Drive motor 45 ... Suction pipe 51 ... Carbon dioxide gas inlet 47 ... Collision member 55 ... Discharge pipe D ... Carbon dioxide gas according to the second embodiment of the present invention Recovery device 61 ... Carbon dioxide gas inlet E ... Carbon dioxide gas recovery device 81 according to the third embodiment of the present invention ... Carbon dioxide gas inlet 83 ... Ejector 86 ... Water pump

Claims (5)

A carbon dioxide gas recovery device that recovers carbon dioxide gas generated during combustion of fossil fuel,
A roots pump in which a pair of roots rotors housed in a pump casing provided with a suction port and a discharge port are rotatably provided by a drive motor, a suction pipe connected to the suction port, and a discharge connected to the discharge port A pipe that communicates with the suction pipe is provided with a carbon dioxide gas inlet and a collision member that collides the sucked water with the carbon dioxide gas, and the water is discharged from the suction pipe by the operation of the roots pump. A large amount of bubbles are generated by colliding water mixed with carbon dioxide gas taken in from the inlet and colliding with the collision member, and the bubbles are refined by the compression action by the Roots pump. The carbon dioxide gas is dissolved in the water by discharging water containing bubbles of the carbon dioxide gas from the discharge pipe into the water. Carbon gas recovery device. A carbon dioxide gas recovery device that recovers carbon dioxide gas generated during combustion of fossil fuel,
A roots pump in which a pair of roots rotors housed in a pump casing provided with a suction port and a discharge port are rotatably provided by a drive motor, a suction pipe connected to the suction port, and a discharge connected to the discharge port A pipe, and an inlet for carbon dioxide gas is provided in the suction pipe, and bubbles of carbon dioxide gas mixed in water sucked from the suction pipe by the operation of the roots pump are refined by the compression action of the roots pump, A carbon dioxide gas recovery apparatus, wherein carbon dioxide gas is dissolved in water by discharging water containing the refined bubbles into the water from the discharge pipe. A carbon dioxide gas recovery device that recovers carbon dioxide gas generated during combustion of fossil fuel,
A roots pump in which a pair of roots rotors housed in a pump casing provided with a suction port and a discharge port are rotatably provided by a drive motor, a suction pipe connected to the suction port, and a discharge connected to the discharge port A water pump provided to connect the discharge side to the suction side of the suction pipe and the suction pipe. The suction pipe has a built-in ejector and a carbon dioxide gas inlet, and the water pump and the roots pump The bubbles of carbon dioxide gas mixed in the water supplied and sucked from the water pump by the linked operation are refined by the compression action of the roots pump, and the water containing the refined bubbles is discharged into the water from the discharge pipe. A carbon dioxide gas recovery device, wherein carbon dioxide gas is dissolved in water.   The outlet side of the discharge pipe and the suction side of the suction pipe are connected to a tank of a predetermined capacity, respectively, and the water in the tank is circulated and supplied to the Roots pump. The carbon dioxide gas recovery device described in any of the above.   5. The carbon dioxide gas recovery apparatus according to claim 1, wherein the roots rotor is a two-leaf type roots rotor.

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