JP5627513B2 - Methane gas purification system for biogas power generation system - Google Patents

Description

The present invention relates to a technology for methane gas purifying apparatus for removing the impurities act of microorganisms such as hydrogen sulfide contained in the biogas, in particular, methane gas purification device comprising a biological desulfurization tank filler microorganisms fixing is filled Regarding technology.

  Methane gas (methane in the gaseous state) is produced by methane fermentation using organic anaerobic bacteria, such as sewage sludge, organic waste water, food residues such as moss, and discarded organic waste. A biogas power generation apparatus that generates a biogas, which is a mixed gas containing as a main component, and uses the biogas as a fuel gas is known (for example, see Patent Document 1).

When biogas is used as fuel gas, biogas contains many impurities, and if used as it is, it will have a negative effect on the power generation device and the environment. Therefore, it is necessary to purify biogas and remove impurities. is there. As a method for removing (desulfurizing) sulfur which is one of the impurities, a method using a methane gas purification apparatus for removing impurities such as hydrogen sulfide contained in biogas by the action of microorganisms is known (for example, patents). Reference 2).

JP 2002-275482 A JP 2006-143781 A

The methane gas purification apparatus includes a biological desulfurization tank that is filled with a filler that fixes microorganisms. Conventionally, microorganisms are fixed on the filler by spraying water containing microorganisms, for example, treated water, onto the filler from the upper part of the biological desulfurization tank. As a method for spraying treated water, spray spraying by compression using a spray nozzle or the like is conventionally known. However, in spray spraying by compression, since the treated water contains sludge and the like, clogging occurs in the spray nozzle, and the treated water may not be sprayed.
Further, as a method of spraying treated water, there is spraying by natural flow using a watering plate provided with a plurality of discharge holes. In this method, treated water is allowed to flow down on the surface of the water spray plate, and the treated water is allowed to flow from the surface of the water spray plate through the discharge holes to the filler in the biological desulfurization tank. However, when the biological desulfurization tank itself is tilted or when the water spray plate is tilted, the treated water is concentrated at a low position on the surface of the water spray plate, and the treated water is discharged from the discharge hole arranged at the low position. Due to the flow down, there was an uneven distribution of treated water.

Therefore, in view of the problem related to the present invention, even if solids such as sludge are contained in water containing microorganisms, water containing microorganisms can be sprayed, even when the biological desulfurization tank is inclined, Provided is a methane gas purification device capable of evenly spraying water containing microorganisms.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

In claim 1, a biogas power generation system is constituted by a fermenter, a methane gas purification device, and a gas engine generator, and organic waste is fermented in the fermentor to generate biogas. In the configuration in which impurities such as hydrogen sulfide contained in the gas are removed by the methane gas purification device, and the biogas from which the impurities have been removed is supplied to the gas engine generator, the methane gas purification device is a filler that fixes microorganisms. A biological desulfurization tank filled with water, a water supply pipe connected to the top of the biological desulfurization tank and spraying water containing microorganisms, a drain pipe connected to the bottom of the biological desulfurization tank and discharging water in the biological desulfurization tank, An air injection device for injecting air into the inlet of the biological desulfurization tank, and in the biological desulfurization tank, above the filler, below the discharge part of the water supply pipe, over the entire surface of the biological desulfurization tank. A sprinkling plate is disposed, a plurality of discharge holes are formed in the sprinkling plate, and a coupling portion configured in a cylindrical shape is provided upward from each discharge hole, and a pipe-like overflow fluid is formed in the coupling portion. Can be fitted, and the height of the overflow fluid with respect to the connecting portion can be adjusted .

  As effects of the present invention, the following effects can be obtained.

In claim 1, a biogas power generation system is constituted by a fermenter, a methane gas purification device, and a gas engine generator, and organic waste is fermented in the fermentor to generate biogas. In the configuration in which impurities such as hydrogen sulfide contained in the gas are removed by the methane gas purification device, and the biogas from which the impurities have been removed is supplied to the gas engine generator, the methane gas purification device is a filler that fixes microorganisms. A biological desulfurization tank filled with water, a water supply pipe connected to the top of the biological desulfurization tank and spraying water containing microorganisms, a drain pipe connected to the bottom of the biological desulfurization tank and discharging water in the biological desulfurization tank, An air injection device for injecting air into the inlet of the biological desulfurization tank, and in the biological desulfurization tank, above the filler, below the discharge part of the water supply pipe, over the entire surface of the biological desulfurization tank. A sprinkling plate is disposed, a plurality of discharge holes are formed in the sprinkling plate, and a coupling portion configured in a cylindrical shape is provided upward from each discharge hole, and a pipe-like overflow fluid is formed in the coupling portion. Since the height of the overflow fluid with respect to the joint portion can be adjusted , the water containing microorganisms is biased and stored due to the inclination and deflection of the water spray plate, the inclination of the biological desulfurization tank, etc. Even if the height of the inlet of the discharge hole is made equal by the overflow fluid, it can be sprayed evenly.

  Even when water containing microorganisms is biased and stored due to inclination or deflection of the water spray plate, inclination of the biological desulfurization tank, etc. Can be sprayed on.

1 is an overall configuration diagram of a biogas power generator according to an embodiment of the present invention. The block diagram of the biological desulfurization tank which concerns on one Embodiment of this invention. (A) Top view of the watering board which concerns on one Embodiment of this invention (b) Side surface sectional drawing similarly. The cross-sectional enlarged view of the discharge hole and overflow fluid which concern on one Embodiment of this invention. The cross-sectional enlarged view of the overflow fluid of the state couple | bonded with the discharge hole which concerns on one Embodiment of this invention, and a discharge hole. Side surface sectional drawing which shows the biological desulfurization tank and watering board of the tilted state which concern on one Embodiment of this invention.

First, an overall configuration of a power generation system 100 including a biogas methane gas purification device 2 according to an embodiment of the present invention will be described with reference to FIG.

The power generation system 100 purifies biogas generated by gasification of organic waste using the methane gas purification device 2, and generates power using the purified biogas. The power generation system 100 includes a fermenter 1, a methane gas purification device 2 , a gas holder 3, a gas engine generator 4, and a gas passage 5 connecting the respective devices.

  The fermenter 1 generates biogas by gasification of organic waste. The fermenter 1 is, for example, a UASB type reaction vessel. The fermenter 1 is supplied with organic waste water, which is a kind of organic waste, via a waste water supply unit, and granule cells. Thereby, in the fermenter 1, methane fermentation is performed, the organic substance contained in organic waste water is decomposed | disassembled into methane and a carbon dioxide gas, and biogas is generated. Biogas is a mixed gas mainly composed of methane, and contains hydrogen sulfide, carbon dioxide gas, and the like as other components.

The methane gas purification device 2 purifies the biogas by removing hydrogen sulfide in the biogas generated by the gasification of organic wastewater in the fermenter 1. The methane gas purification device 2 is installed in the middle of biogas flowing out of the fermenter 1 and reaching the gas engine generator 4. The methane gas purification device 2 includes a biological desulfurization tank 11 and an air injection device 13.

The biological desulfurization tank 11 desulfurizes biogas using microorganisms. The biological desulfurization tank 11 is connected to the fermenter 1 via the first gas pipe 21 that is the gas passage 5 , and is disposed on the downstream side of the fermenter 1 in the biogas flow direction.
The biological desulfurization tank 11 removes hydrogen sulfide in the biogas because the hydrogen sulfide in the biogas generated in the fermenter 1 corrodes the gas engine generator 4 that uses the biogas as a fuel gas.

  As shown in FIGS. 1 and 2, the biological desulfurization tank 11 is provided with a packed bed 31 filled with a plurality of fillers 31 a in order to enlarge the fixed area of microorganisms, as shown in FIGS. 1 and 2. The filling layer 31 is randomly filled with a plurality of fillers 31a. The filler 31a is formed in a cylindrical shape with a material capable of fixing microorganisms on its surface, and is formed of, for example, polypropylene. In the biological desulfurization tank 11, a water level sensor 32 that detects the water level of the treated water stored in the biological desulfurization tank 11 is provided.

The air injection device 13 is a device for injecting air into biogas. The air injecting device 13 has a fan and a blower side valve, and air is supplied to the biogas flowing through the first gas pipe 21 which is the gas passage 5 connecting the fermenter 1 and the biological desulfurization tank 11 through the injecting pipe 26. Configured to be infused. In the desulfurization reaction in the biological desulfurization tank 11, microorganisms actively work in an aerobic environment. Therefore, before the biogas flows into the biological desulfurization tank 11, air is injected into the biogas from the air injection device 13, thereby activating the activity of microorganisms. In addition, the air injection device 13 is configured to be able to adjust the amount of air injected into the biogas by adjusting the rotational speed of the fan and adjusting the opening of the blower side valve. In addition, although the air injection apparatus 13 was set as the structure which has a fan in this embodiment, it is not limited to this. For example, the air injection device 13 can be configured to include a pump and a compressor.

The gas holder 3 is a device for temporarily storing biogas purified by the methane gas purification device 2 and adjusting the amount of biogas supplied when the purified biogas is supplied to the gas engine generator 4. The gas holder 3 is connected to the biological desulfurization tank 11 via the second gas pipe 22, and is disposed downstream of the biological desulfurization tank 11 in the biogas flow direction.

The gas engine generator 4 generates power using the biogas purified by the methane gas purification device 2 as fuel gas. The gas engine generator 4 includes a gas engine and a generator. In the gas engine generator 4, the gas engine and the generator are connected to each other, and the generator or magnet of the generator is rotated by the rotation of the output shaft of the gas engine, thereby generating power. The gas engine generator 4 is provided downstream of the gas holder 3.

Moreover, the fermenter 1, the methane gas refiner | purifier 2 , the gas holder 3, and the gas engine generator 4 were comprised by the 1st gas pipe 21, the 2nd gas pipe 22, and the 3rd gas pipe 23 which distribute | circulate biogas and air. The gas passages 5 are connected in the order described above.
That is, the gas passage 5 includes a first gas pipe 21, a second gas pipe 22, and a third gas pipe 23. The first gas pipe 21 connects the fermenter 1 and the biological desulfurization tank 11 of the methane gas purification device 2 to circulate biogas from the fermenter 1 toward the biological desulfurization tank 11 and to inject the biogas with an air injection device. The air injected by 13 is circulated. The second gas pipe 22 connects the biological desulfurization tank 11 of the methane gas purification device 2 and the gas holder 3, and distributes the desulfurized biogas and air from the biological desulfurization tank 11 toward the gas holder 3. The third gas pipe 23 connects the gas holder 3 and the gas engine generator 4, and causes the biogas and air purified by the methane gas purification device 2 to flow from the gas holder 3 toward the gas engine generator 4. In the middle of the first gas pipe 21, an injection pipe 26 for injecting air from the air injection device 13 is connected. In addition, the second gas pipe 22 is provided with a gas valve 33, and by opening and closing the gas valve 33, it is possible to switch inflow or stop of biogas and air downstream from the second gas pipe 22.

The methane gas purification device 2 is connected to the upper part of the biological desulfurization tank 11, a water supply pipe 35 for spraying water (treated water) containing microorganisms, a water supply valve 36 for opening and closing the water supply pipe 35, and the biological desulfurization tank 11. And a drain valve 37 for discharging treated water in the biological desulfurization tank 11 and a drain valve 38 for opening and closing the drain pipe 37.

Further, the methane gas purification device 2 includes a control device 40 that controls opening and closing of the gas valve 33, the water supply valve 36 and the drain valve 38. The control device 40 is connected to the water level sensor 32, the gas valve 33, the water supply valve 36 and the drain valve 38. The control device 40 can control the opening and closing of the gas valve 33. The gas valve 33 is open during normal operation. Further, the control device 40 closes the gas valve 33 when performing opening / closing control for fixing microorganisms in the biological desulfurization tank 11 in a state where the biogas does not flow into the biological desulfurization tank 11. Further, when the operation of the entire power generation system 100 is stopped, the gas valve 33 is closed.

  The upstream end of the water supply pipe 35 is connected to the fermenter 1 in the flow direction of the treated water. The upstream end of the water supply pipe 35 is connected to the upper part of the fermenter 1. The fermenter 1 is supplied with organic wastewater, which is a kind of organic waste, via a wastewater supply unit. In the fermenter 1, treated water after methane fermentation is performed is supplied to the water supply pipe 35. Inflow. Here, the treated water is water containing organic waste water after methane fermentation as a main component and containing microorganisms such as sulfur-oxidizing bacteria. The downstream end of the water supply pipe 35 is inserted into the biological desulfurization tank 11 from the upper part of the biological desulfurization tank 11.

  A water supply valve 36 is provided in the middle of the water supply pipe 35. The water supply valve 36 is a solenoid valve. The water supply pipe 35 can be opened and closed by electrically opening and closing the electromagnetic valve.

  Further, a water spray plate 41 is provided at a position above the biological desulfurization tank 11 and below the downstream end of the water supply pipe 35. As shown to Fig.3 (a), the watering board 41 is formed in planar view circular shape, and the outer edge part 41a is formed in the outer periphery. The outer edge portion 41a is formed in a step shape higher than other portions. Moreover, the latching part 11a is formed in planar view cyclic | annular form in the inner surface of the biological desulfurization tank 11, and as shown in FIG.3 (b), the lower surface of the outer edge part 41a of the water spray plate 41 is the biological desulfurization tank 11's inside. The water spray plate 41 is supported by the latching part 11a by contact | abutting with the upper surface of the latching part 11a provided in the inner surface. By comprising in this way, it prevents that treated water flows down from the outer edge part 41a. Moreover, since the water spray plate 41 is only supported from the lower part by the latching | hanging part 11a, when visually confirming the biological desulfurization tank 11 from upper direction, or maintaining the biological desulfurization tank 11 or the water spray plate 41, water spraying is carried out. The plate 41 can be easily moved upward.

  As shown in FIG. 3, the water spray plate 41 is provided with a plurality of discharge holes 42. The discharge holes 42 are arranged on the water spray plate 41 so that the distances between them are equal. In the present embodiment, the discharge holes 42 are arranged in a plurality of rows. In addition, the arrangement of the discharge holes 42 is not limited to this. For example, the discharge holes 42 can be arranged uniformly on the circumference of a concentric circle.

  Further, the discharge hole 42 is formed in a circular shape. The diameter of the discharge hole 42 is larger than the diameter of the solid substance existing in the treated water. Specifically, the discharge hole 42 has a diameter of several centimeters. With this configuration, there is no possibility that the discharge hole 42 is clogged with solid matter in the treated water.

  Further, as shown in FIG. 3B, a coupling portion 42 a is erected upward from the lower surface of the discharge hole 42. The coupling portion 42 a is formed in a cylindrical shape, and its outer diameter is formed to be equal to the inner diameter of the discharge hole 42. A flange portion 42b is provided at the lower portion of the coupling portion 42a, and prevents the coupling portion 42a from coming out above the discharge hole 42. A screw groove is provided on the outer periphery of the coupling portion 42a. A lock nut 42c is screwed to the coupling portion 42a, and the coupling portion 42a can be prevented from moving downward by fastening the lock nut 42c. Moreover, it can prevent that the coupling | bond part 42a moves upwards, when the lower surface of the water spray plate 41 and the upper surface of the flange part 42b contact | abut.

  An overflow fluid 45 is detachably provided on the upper portion of the discharge hole 42. As shown in FIG. 4, the overflow fluid 45 is formed in a pipe shape and has an inner diameter equal to the inner diameter of the coupling portion 42a. A lower portion of the overflow fluid 45 is provided with an overflow fluid coupling portion 45a for coupling with the coupling portion 42a. The overflow fluid coupling portion 45a is formed so that its inner diameter is equal to the outer diameter of the coupling portion 42a. A screw groove is provided on the inner periphery of the overflow fluid coupling portion 45a. The overflow fluid 45 is fixed to the upper portion of the discharge hole 42 by screwing the overflow fluid coupling portion 45a into the coupling portion 42a. The overflow fluid 45 can also be removed from the coupling portion 42a. With this configuration, the overflow fluid 45 is provided so as to be detachable from the discharge hole 42. Further, since the overflow fluid 45 is screwed into the coupling portion 42 a, the treated water flows into the discharge hole 42 only from the hole provided on the upper surface of the overflow fluid 45.

  Next, a method for adjusting the height of the overflow fluid 45 will be described. As shown in FIG. 5, an overflow fluid side lock nut 45b is screwed to the coupling portion 42a below the overflow fluid 45 and above the lock nut 42c. The lock nut 42c is movable in the axial direction of the coupling portion 42a. When the overflow fluid coupling portion 45a of the overflow fluid 45 is screwed into the coupling portion 42a, the overflow fluid side lock nut 45b is fastened from below to overflow when the upper end of the overflow fluid 45 reaches a desired height. The fluid 45 is fixed. In this way, the overflow fluid 45 is fixed at an arbitrary height. The method for adjusting the height of the overflow fluid 45 is not limited to the method described in the present embodiment. For example, the overflow fluid 45 is fitted in the coupling portion 42a so as to be slidable in the axial direction. It can also be fixed by tightening with a ring or the like from the outside at a desired position.

  For example, when the water spray plate 41 is tilted or bent due to the weight of the treated water, or when the biological desulfurization tank 11 is inclined when the biological desulfurization tank 11 is installed, as shown in FIG. The treated water is unevenly distributed on the left side in FIG. In addition, in FIG. 6, the case where the biological desulfurization tank 11 itself has inclination is represented. In such a case, the overflow fluid 45 located on the side where the treated water is biased (left side in FIG. 6) is moved upward so that the heights of the upper surfaces of all the overflow fluids 45 are adjusted to be the same.

  With this configuration, when the treated water flows into the water spray plate 41 from the upper water supply pipe 35 of the biological desulfurization tank 11, when the water level of the treated water does not exceed the overflow fluid 45, The treated water does not flow down the plate 41. When the surface of the treated water reaches a height exceeding the overflow fluid 45, the treated water flows down through the overflow fluid 45 and the discharge hole 42 to the packed bed 31 below the spray plate 41. At this time, since the height of the upper surface of the overflow fluid 45 is the same, the treated water is uniformly sprayed from the entire water spray plate 41. By comprising in this way, microorganisms can be fixed to the surface of the filling body 31a because treated water adheres uniformly to the filling body 31a in the filling layer 31.

  The upstream end of the drain pipe 37 is connected to the bottom of the biological desulfurization tank 11. The treated water sprayed into the biological desulfurization tank 11 from the water supply pipe 35 connected to the upper part of the biological desulfurization tank 11 falls to the bottom of the biological desulfurization tank 11, and passes through the water sealing tank (not shown) from the drain pipe 37. It is discharged into a treated water storage tank (not shown). A drain valve 38 is provided in the middle of the drain pipe 37. The drain valve 38 is a solenoid valve, and the drain pipe 37 can be opened and closed by electrically controlling and opening and closing the solenoid valve.

  The control device 40 is connected to the water level sensor 32, the gas valve 33, the water supply valve 36, and the drain valve 38. The control device 40 includes a storage unit configured with a RAM, a ROM, and the like, and an arithmetic unit configured with a CPU and the like. The control device 40 fixes microorganisms in the biological desulfurization tank 11 by controlling opening and closing of the water supply valve 36 and the drain valve 38.

As described above, the methane gas purification apparatus 2 includes the biological desulfurization tank 11 filled with the filler 31a in which microorganisms are fixed, the water supply pipe 35 connected to the upper part of the biological desulfurization tank 11 and spraying treated water, and the biological desulfurization tank 11. A methane gas purification device 2 comprising a drain pipe 37 connected to the bottom of the sewage tank 11 for discharging treated water in the biological desulfurization tank 11 and an air injection device 13 for injecting air into the inlet of the biological desulfurization tank 11, The desulfurization tank 11 includes a water spray plate 41 provided above the filler 31a. The water spray plate 41 has a plurality of discharge holes 42, and a pipe-like overflow fluid 45 is provided on the upper surface of each discharge hole 42. It is a thing. With this configuration, even if treated water is stored unevenly due to the inclination or deflection of the water spray plate 41, the inclination of the biological desulfurization tank 11, etc., the height of the inlet of the discharge hole 42 is increased by the overflow fluid 45. By equalizing the thickness, it is possible to spray evenly. Moreover, the height of the overflow fluid 45 can be easily adjusted at the place where the biological desulfurization tank 11 is installed in accordance with the inclination and deflection of the water spray plate 41 and the change in the inclination of the biological desulfurization tank 11.

  Further, the height of the overflow fluid 45 can be adjusted. With such a configuration, even when water containing microorganisms is biased and stored due to the inclination and deflection of the water spray plate 41, the inclination of the biological desulfurization tank 11, and the like, the inlet of the discharge hole 42 by the overflow fluid 45 is stored. By equalizing the heights, it is possible to spread evenly.

DESCRIPTION OF SYMBOLS 1 Fermenter 2 Methane gas refiner 3 Gas holder 4 Gas engine generator 5 Gas passage 11 Biodesulfurization tank 13 Air injection device 31 Packing layer 31a Filler 32 Water level sensor 33 Gas valve 35 Water supply pipe 36 Water supply valve 37 Drain pipe 38 Drain valve 40 Control device 41 Sprinkler plate 42 Discharge hole 45 Overflow fluid 100 Power generation system

Claims (1)

The biogas power generation system is composed of the fermenter, methane gas purification device, and gas engine generator.
Organic waste is fermented in the fermentor to generate biogas, impurities such as hydrogen sulfide contained in the generated biogas are removed by the methane gas purification device, and the biogas from which impurities have been removed In the configuration for supplying to the gas engine generator,
The methane gas purification apparatus includes a biological desulfurization tank filled with a filler that fixes microorganisms, a water supply pipe connected to an upper part of the biological desulfurization tank and spraying water containing microorganisms, and a biological desulfurization tank connected to the bottom of the biological desulfurization tank. A drain pipe for discharging the water in the desulfurization tank, and an air injection device for injecting air into the inlet of the biological desulfurization tank,
In the biological desulfurization tank, a water spray plate is disposed over the entire surface of the biological desulfurization tank above the filler and below the discharge portion of the water supply pipe.
A plurality of discharge holes are drilled in the water spray plate, and a coupling portion configured in a cylindrical shape is formed upward from each discharge hole, and a pipe-like overflow fluid can be fitted into the coupling portion.
Adjustable height of overflow fluid relative to the joint
A methane gas refining device for a biogas power generation system.

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