JP2017074549A - Biogas generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biogas generator having high energy recovery efficiency.SOLUTION: A biogas generator comprises a pretreatment tank having an opening in a lower part thereof, and a siphon type fermentation tank for producing biogas from a fermentation liquid containing a biomass raw material supplied through the opening of the pretreatment tank. The fermentation tank includes: a raw material charging port provided in a lower part thereof and connected to the opening; a discharge port provided at a position separated from the raw material charging port in an upper part of the fermentation tank to discharge the biogas; a first partition wall extending from a top plate to a first height position near a first predetermined distance of a bottom plate at a position between the raw material charging port and the discharge port and partitioning the fermentation tank into a first tank where a space above an opening is sealed and the raw material charging port is provided in a lower part and a second tank communicating with the first tank at a bottom thereof and provided with a discharge port in an upper part thereof; and a U-shaped tube having a first end and a second end and inserted through the opening of the first partition wall at an intermediate portion between the first end and the second end, wherein the first end and the second end extend upward with respect to the intermediate portion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a biogas generator.

  Conventionally, a receiving part for receiving the waste pulverization waste liquid is provided, and a solid-liquid separation tank that precipitates and separates the waste pulverization waste liquid is provided, and the liquid phase separated in the solid-liquid separation tank is drained to the outside. The solid-liquid separation tank is provided with an anaerobic fermentation tank that receives the precipitate separated in the solid-liquid separation tank and converts it into biogas, and settles from the solid-liquid separation tank to the anaerobic fermentation tank An advection part for advancing the material is provided, and the solid-liquid separation of the solid component from the anaerobic fermenter of the solid component is performed by blocking the space between the solid-liquid separation tank and the anaerobic fermenter in the advection part. While providing a constriction part that can prevent backflow to the tank, the precipitate is transferred to the anaerobic fermentation tank through the constriction part, and the excess liquid phase of the anaerobic fermentation tank is transmitted through the constriction part. Precipitation advancing mechanism that enables return to solid-liquid separation tank The anaerobic provided to the fermentor, wherein the anaerobic fermentation tank, there is a waste water treatment device provided with a biogas extraction passage for taking out the generated biogas to the outside (for example, see Patent Document 1).

  This wastewater treatment device is equipped with an agitation pump that supplies anaerobic gas to a storage tank, a pump for a gas lifter that returns anaerobic gas to a return pipe, and a diffuser that supplies anaerobic gas to an aeration device that diffuses anaerobic gas into an anaerobic fermentation space. A gas pump and a stirring pump for supplying anaerobic gas to the solid-liquid separation tank are included.

  There is also a methane fermentation continuous operation device having a non-powered stirring mechanism. The fermenter is divided into four chambers by a partition plate, a U-tube is inserted into the partition plate between the first chamber and the second chamber, and the gas phase portion of the first chamber pushes down the liquid level with biogas. When the liquid level of the first chamber reaches the bottom of the U-shaped tube, the biogas stored in the gas phase of the first chamber moves to the second chamber through the U-shaped tube, and the fermentation liquid enters the first chamber. Withdrawn, the liquid level in the first chamber rises and the liquid level in the second to fourth chambers falls. Stirring in the fermenter is performed by the liquid flow generated at this time. However, the raw material (simulated food waste) is supplied to the boundary between the first chamber and the second chamber at the bottom of the fermenter by a timer-controlled pump (see Non-Patent Document 1, for example).

JP 2013-027851 A

Development of a new low-cost methane fermentation reactor with a non-powered stirring mechanism, Takuro Kobayashi, Shin Usami, Yu Yu Li, Journal of Japan Society on Water Environment Vol. 33, No. 12, pp. 201-208 (2010 )

  By the way, the wastewater treatment apparatus described in Patent Document 1 is considerably suitable for driving a diffuser pump that forms a gas-liquid mixed phase flow in an anaerobic fermenter when biogas is generated from biomass raw material that is renewable energy. Since electric power is required, there is a problem that energy recovery efficiency is lowered.

  Moreover, since the methane fermentation continuous operation apparatus described in Non-Patent Document 1 uses a pump to supply biomass raw material to the fermenter, there is room for improvement in energy recovery efficiency.

  Therefore, an object is to provide a biogas generator with high energy recovery efficiency.

  The biogas generator according to the embodiment of the present invention is a pretreatment tank for precipitating a biomass raw material in water, and is supplied through a pretreatment tank having an opening in the lower portion and the opening of the pretreatment tank. And a siphon-type fermenter that stores bioferment containing the biomass raw material in the presence of microorganisms to generate biogas, and the fermenter is provided at a lower portion of the fermenter, and is provided at the opening. A raw material input port to be connected, a discharge port for discharging the biogas provided in an upper portion of the fermenter at a position spaced from the raw material input port in plan view, and the raw material input port and the discharge port in plan view A first partition that extends from the top plate of the fermenter to a first height position before the first predetermined distance of the bottom plate in the fermenter, and has a through hole, The space above the through hole is sealed In addition, the fermenter includes a first tank in which the raw material charging port is provided in the lower part, and a second tank in communication with the first tank at the bottom of the fermenter and in which the discharge port is provided in the upper part. A U-shaped tube having a first partition that divides the internal space of the first partition and a first end and a second end, wherein the through-hole of the first partition is at an intermediate portion between the first end and the second end And a U-shaped tube with the first end and the second end extending upward with respect to the intermediate portion.

  A biogas generator with high energy recovery efficiency can be provided.

1 is a cross-sectional view showing a biogas generator 100. FIG. It is a figure which shows the A1-A2 arrow cross section of the biogas generator 100 shown in FIG. It is a figure which shows the process in which the biogas generator 100 produces | generates biogas in steps. It is a figure which shows the process in which the biogas generator 100 produces | generates biogas in steps. 1 is a diagram showing a general methane fermentation system 500. FIG. It is a figure which shows an electric power balance.

  Embodiments to which the biogas generator of the present invention is applied will be described below.

<Embodiment>
FIG. 1 is a cross-sectional view showing a biogas generator 100. FIG. 2 is a view showing a cross section taken along arrow A1-A2 of the biogas generating apparatus 100 shown in FIG. In addition, FIG. 1 shows the whole cross section of the biogas generator 100 in the position corresponded to the B1-B2 arrow cross section in FIG.

  1 and 2, an XYZ coordinate system that is an orthogonal coordinate system is defined as illustrated. Here, as an example, the XY plane is a horizontal plane, and the positive Z-axis direction is vertically upward. The plan view refers to viewing the XY plane from the positive direction of the Z axis.

  The biogas generator 100 includes a treatment tank 110 as a main component. The biogas generation apparatus 100 includes, in addition to the processing tank 110, an apparatus for processing biogas generated in the processing layer 110, an apparatus for processing wastewater of the processing layer 110, and the like, which are omitted in FIG.

  The processing tank 110 includes a bottom plate 111, a side wall 112, a top plate 113, a partition plate 114, partition walls 115, 116, 117, a U-shaped tube 118, a baffle plate 119A, a partition plate 119B, and a partition board 119C.

  As shown in FIG. 2, the bottom plate 111 is a plate member having a rectangular shape in plan view, and is located at the bottom of the processing tank 110. The bottom plate 111 is the bottom of the processing tank 110.

  The side wall 112 has side walls 112A, 112B, 112C, and 112D (see FIG. 2). The side walls 112 </ b> A, 112 </ b> B, 112 </ b> C, and 112 </ b> D are arranged in a rectangular ring shape in plan view along the four sides of the bottom plate 111 in this order. For this reason, FIG. 1 shows a cross section of only the side walls 111A and 111C.

  The side walls 112 </ b> A, 112 </ b> B, 112 </ b> C, and 112 </ b> D are rectangular plate-like members, respectively, and surround the four side surfaces of the processing tank 110. The side wall 112 </ b> A is provided with an inlet 112 </ b> E through which slurry containing biomass material flows into the treatment tank 110. The inflow port 112E is provided at a position close to the top plate 113 in the Z-axis direction.

  Further, the side wall 112C is provided with a discharge port 112F for discharging the liquid. The discharge port 112F is provided at a position close to the top plate 113 in the Z-axis direction.

  In the following description, the side walls 112A, 112B, 112C, and 112D are simply referred to as the side walls 112 unless particularly distinguished.

  The top plate 113 is a rectangular plate-like member in plan view, and is provided on the upper surface of the processing tank 110. Here, as an example, the size of the top plate 113 in plan view is assumed to be equal to the bottom plate 111. The top plate 113 is provided with a discharge port 113A for discharging biogas.

  The bottom plate 111, the side wall 112, and the top plate 113 are made of, for example, metal or resin, and are fixed to each other to form a rectangular parallelepiped internal space. When the bottom plate 111, the side wall 112, and the top plate 113 are made of metal, they may be fixed by welding or screwing. When the bottom plate 111, the side wall 112, and the top plate 113 are made of resin, they may be fixed by bonding or screwing. Further, the surface of the bottom plate 111, the side wall 112, and the top plate 113 may be subjected to painting or antiseptic treatment as necessary.

  The partition plate 114, the partition walls 115, 116, 117, the U-shaped tube 118, the baffle plate 119A, the partition plate 119B, and the partition board 119C are disposed in an internal space constructed by the bottom plate 111, the side wall 112, and the top plate 113. The The partition plate 114, the partition walls 115, 116, 117, the U-shaped tube 118, the baffle plate 119A, the partition plate 119B, and the partition board 119C are made of metal or resin, for example.

  When the partition plate 114, the partition walls 115, 116, 117, the U-shaped tube 118, the baffle plate 119A, the partition plate 119B, and the partition board 119C are made of metal, they may be fixed by welding or screwing. When the partition plate 114, the partition walls 115, 116, 117, the U-shaped tube 118, the baffle plate 119A, the partition plate 119B, and the partition board 119C are made of resin, they may be fixed by bonding or screwing. Further, the surface of the partition plate 114, the partition walls 115, 116, 117, the U-shaped tube 118, the baffle plate 119A, the partition plate 119B, and the partition board 119C may be subjected to coating or antiseptic treatment as necessary.

  The partition plate 114 is a plate-like member disposed in parallel with the YZ plane inside the processing tank 110. The partition plate 114 extends from the bottom plate 111 to the top plate 113 from the position of the height h1 in the Z-axis direction. The height h1 is an example of a second height, and the length from the bottom plate 111 to the lower end 114A is an example of a second predetermined distance.

  Further, the partition plate 114 extends from the side wall 112B to the side wall 112D in the Y-axis direction. The lower end 114A of the partition plate 114 is located at a height h1 from the bottom plate 111 over the Y-axis direction between the side wall 112B and the side wall 112D.

  Three sides other than the lower end 114 </ b> A of the partition plate 114 are fixed to the side walls 112 </ b> B and 112 </ b> D and the top plate 113.

  The partition plate 114 having such a configuration partitions the internal space of the processing tank 110 into an X-axis negative direction side and an X-axis positive direction side at a position higher than the height h1 from the bottom plate 111. Moreover, the partition plate 114 constructs a slit 114 </ b> B having a height h <b> 1 at the bottom of the internal space of the processing tank 110. The slit 114B has a height of h1 and is provided between the side wall 112B and the side wall 112D.

  Here, in the treatment tank 110, the X-axis negative direction side from the partition plate 114 is referred to as a pretreatment tank 120, and the X-axis positive direction side from the partition plate 114 is referred to as a fermentation tank 130. The pretreatment tank 120 and the fermentation tank 130 extend between the bottom plate 111 and the top plate 113 in the Z-axis direction, and the pretreatment tank 120 and the fermentation tank 130 are positioned below the partition plate 114. Are communicated by slits 114B.

  The slit 114 </ b> B is an example of an opening provided in the lower part of the pretreatment tank 120 and an example of a raw material inlet provided in the lower part of the fermentation tank 130.

  That is, the treatment tank 110 includes a pretreatment tank 120 and a fermentation tank 130. The pretreatment tank 120 and the fermentation tank 130 are partitioned by a partition plate 114. Such a treatment tank 110 is obtained by integrating the pretreatment tank 120 and the fermentation tank 130.

  Note that the pretreatment tank 120 may be regarded as an adjustment tank or a solid-liquid separation tank. Moreover, you may catch the fermenter 130 as an anaerobic fermenter.

  The pretreatment tank 120 is a tank that stores a slurry containing a biomass material and performs a pretreatment for precipitating the biomass material. Since there are no microorganisms in the pretreatment tank 120, biogas is not generated.

  The slurry containing the biomass raw material is a liquid in which the biomass raw material is mixed with water, and is called a substrate. In FIG. 1, the substrate 10 is shown by a dark dot pattern. Biomass raw material contained in the substrate 10 is precipitated in the lower part of the pretreatment tank 120. In FIG. 1, the precipitate 11 is shown in dark gray. The substrate 10 is supplied to the fermenter 130 from the slit 114 </ b> B of the pretreatment tank 120, and becomes the fermentation liquid 20 inside the fermenter 130. FIG. 1 shows the fermented liquid 20 in a thin dot pattern. The fermentation broth 20 is mixed with microorganisms that decompose the biomass material.

  Here, the biomass raw material is, for example, organic matter such as food waste, sewage sludge, livestock waste, etc., and the biogas is decomposed by contact with the microorganism under anaerobic conditions. It is a generated raw material.

  The biogas is a gas generated by decomposing a biomass raw material inside the fermenter 130. Here, although the form which produces | generates methane gas from the biomass raw material containing food waste is demonstrated, about 55%-about 65% of the biogas produced | generated with the fermenter 130 is methane gas, and the remainder is carbon dioxide etc. .

  The fermenter 130 is a tank that is supplied with microorganisms under anaerobic conditions and generates biogas using the substrate 10 supplied from the pretreatment tank 120 via the slit 114B. The fermenter 130 has a siphon type configuration.

  Moreover, since only the main components are shown in FIG. 1, illustration is omitted, but a hot water circulation pump is connected to the fermenter 130. The fermentation liquid 20 is maintained at a temperature suitable for fermentation (for example, a temperature in the range of 30 ° C. to 60 ° C., for example, 35 degrees or 55 degrees) by a hot water circulation pump.

  In the fermenter 130, the partition walls 115, 116, and 117 are provided in this order from the X-axis negative direction side to the X-axis positive direction side.

  Here, the internal space of the fermenter 130 will be described as being divided into four chambers 131, 132, 133, and 134 by three partition walls 115, 116, and 117. The four chambers 131, 132, 133, and 134 communicate with each other.

  Moreover, the liquid level of the fermentation liquid 20 inside the chamber 131 is shown as a liquid level 20A. Moreover, since the liquid level of the fermentation liquid 20 inside the chambers 132 to 134 is equal to each other, it is shown as a liquid level 20B. Here, as an example, the liquid level 20A of the fermentation liquid 20 in the chamber 131 is equal to the liquid level 10A of the substrate 10 of the pretreatment tank 120, and the liquid level 20A and the liquid level 20B of the fermentation liquid 20 are also equal. .

  The partition wall 115 is a plate-like member disposed in parallel with the YZ plane inside the processing tank 110. The partition 115 is an example of a first partition.

  The partition wall 115 extends from the bottom plate 111 to the top plate 113 from the position of the height h2 in the Z-axis direction. The partition 115 extends between the side wall 112B and the side wall 112D in the Y-axis direction. The lower end 115A of the partition wall 115 is located at a height h2 from the bottom plate 111 over the Y-axis direction between the side wall 112B and the side wall 112D. The height h2 is an example of a first height, and the distance from the bottom plate 111 to the lower end 115A is an example of a first predetermined distance.

  Three sides other than the lower end 115 </ b> A of the partition wall 115 are fixed to the side walls 112 </ b> B and 112 </ b> D and the top plate 113.

  The partition wall 115 is provided with a through hole 115B. The through hole 115B is an opening that penetrates the plate-like partition 115 in the X-axis direction (the thickness direction of the partition 115). The position of the through hole 115B in the Y-axis direction is, for example, the center of the length of the partition wall 115 in the Y-axis direction. A U-shaped tube 118 is inserted through the through hole 115B.

  The partition wall 115 having such a configuration partitions the inner space of the fermenter 130 into an X-axis negative direction side and an X-axis positive direction side at a position higher than the height h2 from the bottom plate 111. In addition, the partition wall 115 constructs a slit 115 </ b> C having a height h <b> 2 at the bottom of the internal space of the fermenter 130. The slit 115C has a height of h2 and is provided between the side wall 112B and the side wall 112D.

  Here, in the fermenter 130, the X axis negative direction side from the partition wall 115 is referred to as a chamber 131, the X axis positive direction side from the partition wall 115, and the X axis negative direction side from the partition wall 116 is referred to as a chamber 132. The chamber 131 and the chamber 132 extend between the bottom plate 111 and the top plate 113 in the Z-axis direction, and the chamber 131 and the chamber 132 are communicated with each other by a slit 115C positioned below the partition wall 115. Yes. The chamber 131 is an example of a first tank, and the chamber 132 is an example of a second tank.

  Further, above the lower end 115 </ b> A of the partition wall 115 in the chamber 131, the partition plate 114, the top plate 113, the partition wall 115, and the fermentation broth 20 except that the U-shaped tube 118 communicates with the chamber 132. A space sealed by the liquid level 20A is formed.

  The chamber 131 communicates with the pretreatment tank 120 through the slit 114 </ b> B, and the substrate 10 is supplied from the pretreatment tank 120. Inside the fermenter 130, the substrate 10 is supplied to the entire fermenter 130 from the chamber 131 through the chamber 132, and biogas is generated.

  The biogas generated in the chamber 131 is stored in a space sealed by the upper partition plate 114, the top plate 113, the partition wall 115, and the liquid level 20 </ b> A of the fermentation solution 20.

  The chamber 132 is supplied with the substrate 10 from the chamber 131 and generates biogas. The biogas generated in the chamber 132 passes through the space above the liquid level 20B of the fermentation liquid 20 in the chambers 132 to 134 and is discharged from the discharge port 113A.

  The partition wall 116 is a plate-like member disposed in parallel with the YZ plane inside the processing tank 110. The partition wall 116 is an example of a second partition wall.

  The partition wall 116 extends from the bottom plate 111 to a height h3 in the Z-axis direction. The partition 116 extends between the side wall 112B and the side wall 112D in the Y-axis direction. An upper end 116A of the partition wall 116 is located at a height h3 from the bottom plate 111 over the Y-axis direction between the side wall 112B and the side wall 112D.

  Three sides other than the upper end 116 </ b> A of the partition wall 116 are fixed to the side walls 112 </ b> B and 112 </ b> D and the bottom plate 111.

  The partition wall 116 having such a configuration partitions the inner space of the fermenter 130 into an X-axis negative direction side and an X-axis positive direction side at a position lower than the height h3 from the bottom plate 111.

  Here, in the fermenter 130, the X-axis negative direction side of the partition wall 116 and the X-axis positive direction side of the partition wall 115 are referred to as a chamber 132, and the X-axis positive direction side of the partition wall 116 and the X-axis positive direction side of the partition wall 117. The negative direction side is referred to as a chamber 133. The chamber 132 and the chamber 133 extend between the bottom plate 111 and the top plate 113 in the Z-axis direction, and the chamber 132 and the chamber 133 are communicated by a space above the partition wall 116.

  The chamber 133 is supplied with the substrate 10 through the chamber 132 and generates biogas. The biogas generated in the chamber 133 is discharged from the discharge port 113A through the space above the liquid level B of the fermentation liquid 20 in the chambers 132 to 134.

  The partition wall 117 is a plate-like member disposed in parallel with the YZ plane inside the processing tank 110. The partition wall 117 is an example of a second partition wall. The partition wall 117 extends from the position at the height h2 from the bottom plate 111 to a position at a height h4 from the top plate 113 in the Z-axis direction.

  Further, the partition wall 117 extends from the side wall 112B to the side wall 112D in the Y-axis direction. The lower end 117A of the partition wall 117 is located at a height h2 from the bottom plate 111 over the Y axis direction between the side wall 112B and the side wall 112D. The upper end 117B of the partition wall 117 is at a position below the top plate 113 by a height h4 in the Y-axis direction between the side wall 112B and the side wall 112D.

  Two sides of the partition wall 117 other than the lower end 117A and the upper end 117B are fixed to the side walls 112B and 112D.

  The partition wall 117 having such a configuration is configured such that the inner space of the fermenter 130 is disposed on the X axis negative direction side and the X axis at a position higher than the height h2 from the bottom plate 111 and lower than the top plate 113 by the height h4. It is divided into the positive direction side.

  In addition, the partition wall 117 has a slit 117 </ b> C having a height h <b> 2 at the bottom of the internal space of the fermenter 130. The slit 117C has a height h2, and is provided between the side wall 112B and the side wall 112D. Moreover, the partition wall 117 constructs a slit 117 </ b> D having a height h <b> 4 in the upper part of the internal space of the fermenter 130. The slit 117D has a height of h4 and is provided between the side wall 112B and the side wall 112D.

  Here, in the fermenter 130, the X axis negative direction side from the partition wall 117 and the X axis positive direction side from the partition wall 116 are referred to as a chamber 133, and the X axis positive direction side from the partition wall 117 is referred to as a chamber 134. The chamber 133 and the chamber 134 extend between the bottom plate 111 and the top plate 113 in the Z-axis direction, and the chamber 133 and the chamber 134 are formed by slits 117C and 117D respectively located above and below the partition wall 117. It is communicated.

  In addition, a discharge port 112F for discharging the fermentation liquor 20 is provided in the upper part of the side wall 112C of the chamber 134, and a partition plate 119B and a partition board 119C are provided in the chamber 134. The partition plate 119B and the partition board 119C are provided to guide the fermentation broth 20 to the discharge port 112F.

  The partition plate 119B has plates 119B1 and 119B2. The plate 119B1 has an upper end fixed to the top plate 113, and extends from the side wall 112B to the side wall 112D in the Y-axis direction at the center of the width in the X-axis direction of the chamber 134 and extends in the Z-axis negative direction. .

  The plate 119B2 is attached to the lower end of the plate 119B1. Similarly to the plate 119B1, the plate 119B1 extends from the side wall 112B to the side wall 112D in the Y-axis direction. In the XZ plane, the Y-axis negative direction side is viewed from the Y-axis positive direction side, and the Z-axis positive direction is viewed. The angle is set to 135 degrees in the clockwise direction.

  The partition plate 119 </ b> B constructed by such plates 119 </ b> B <b> 1 and 119 </ b> B <b> 2 is sized so that the lower end is immersed in the fermentation broth 20.

  The partition board 119C has an isosceles right triangle as an example of the XZ cross-sectional shape, and is attached to the side wall 112C. The position in the Z-axis direction where the partition board 119C is attached to the side wall 112C is a position where the partition board 119C is immersed in the fermentation broth 20 (below the liquid level 20B).

  The partition board 119C extends from the side wall 112B to the side wall 112D in the Y-axis direction. The front end 119C1 of the partition board 119C is a portion corresponding to a right apex of the shape of an isosceles right triangle in the XZ cross section, and a slit for guiding the fermentation broth 20A to the discharge port 112F is formed between the lower end of the plate 119B2. doing.

  The liquid level of the fermentation broth 20 in the space surrounded by the partition plate 119B and the partition board 119C as described above in the internal space of the chamber 134 is surrounded by the partition plate 119B and the partition board 119C in the internal space of the chamber 134. It may be different from the liquid level 20B in a space other than the space where

  The chamber 134 is supplied with the substrate 10 through the chambers 132 and 133 to generate biogas. The biogas generated in the chamber 134 passes through the space above the liquid level 20B of the fermentation liquid 20 in the chambers 132 to 134 and is discharged from the discharge port 113A.

  In the chamber 134, the same amount of the fermentation liquor 20 as the substrate 10 supplied from the pretreatment tank 120 to the fermentation tank 130 is discharged from the discharge port 112F.

  The state shown in FIG. 1 is a state where the liquid level 20A and the liquid level 20B are balanced, and the heights of the liquid level 20A and the liquid level 20B are equal. Such a balanced state occurs even after the siphon effect described later occurs.

  In the fermenter 130, in a state where the liquid level 20A and the liquid level 20B are balanced, the liquid levels 20A and 20B are higher than the partition wall 116 and an intermediate portion 118C of the U-shaped tube 118 described later. Fermentation liquid 20 is stored.

  From the state in which the liquid level 20A and the liquid level 20B are balanced, the liquid level 20A is lowered and the liquid level 20B is raised until a siphon effect described later is obtained. That is, since the fermentation liquor 20 is always put in the fermenter 130 to a position higher than the upper end 116A of the partition wall 116, the liquid level 20B of the fermentation liquor 20 in the chambers 132 to 134 among the chambers 131 to 134 is mutually Will be equal.

  Moreover, the space above the liquid level 20A of the fermentation liquid 20 is sealed inside the chamber 131, and the biogas generated in the chamber 131 is a sealed space above the liquid level 20A of the fermentation liquid 20. Accumulate in. For this reason, when the amount of biogas increases and the liquid level 20A of the fermentation liquid 20 in the chamber 131 is pushed down, the fermentation liquid 20 moves from the chamber 131 to the chambers 132 to 134 through the slit 115C.

  Thereby, the difference between the liquid level 20A of the fermentation liquid 20 in the chamber 131 and the liquid level 20B of the fermentation liquid 20 in the chambers 132 to 134 increases.

  The U-shaped tube 118 is a U-shaped tubular member having end portions 118A and 118B and an intermediate portion 118C. The U-shaped tube 118 is a pipe-shaped member that communicates with the inside from the end 118A to the end 118B.

  An intermediate portion 118 </ b> C of the U-shaped tube 118 is inserted into the through hole 115 </ b> B of the partition wall 115. The space between the outer peripheral surface of the intermediate portion 118C and the through hole 115B is sealed. Here, sealing between the outer peripheral surface of the intermediate part 118C and the through hole 115B means sealing so that the fermentation liquor 20 cannot pass between the through hole 115B and the intermediate part 118C.

  For example, when the U-shaped tube 118 is made of resin, the outer peripheral surface of the intermediate portion 118C and the through hole 115B may be sealed by adhering the outer peripheral surface of the intermediate portion 118C to the through hole 115B. For example, when the U-shaped pipe 118 is made of metal, the outer peripheral surface of the intermediate portion 118C and the through hole 115B may be sealed by welding or bonding the outer peripheral surface of the intermediate portion 118C to the through hole 115B.

  The end portions 118A and 118B of the U-shaped tube 118 are bent upward on the Z axis on both sides of the intermediate portion 118C and extended to a predetermined height. Here, as an example, the heights of the end portions 118A and 118B are equal.

  The U-shaped tube 118 is provided for generating a siphon effect between the chamber 131 and the chamber 132. When the difference between the liquid level 20A of the fermentation liquid 20 in the chamber 131 and the liquid level 20B of the fermentation liquid 20 in the chamber 132 increases to some extent as biogas is generated, a siphon effect using the U-shaped tube 118 is obtained.

  When the siphon effect occurs, the fermentation solution 20 moves from the chambers 132 to 134 to the chamber 131. The fermenter 20 in the fermenter 130 is stirred using such movement of the fermenter 20, and the substrate 10 is supplied from the pretreatment tank 120 to the fermenter 130 through the slit 114B without power. A specific operation will be described later with reference to FIGS.

  The height of the intermediate portion 118C of the U-shaped pipe 118 is determined by the size (capacity) of the fermenter 130, the size (capacity) of the chambers 131 to 134, the size of the slits 115C and 117C, the height of the partition wall 116, and the like. In view of this, it may be adjusted to the liquid level 20A of the fermentation liquid 20 in the chamber 131, which is considered to be optimal when the siphon effect is generated.

  Since the height of the intermediate portion 118C is determined by the height of the through-hole 115B of the partition wall 115, the height of the through-hole 115B of the partition wall 115 is the optimum of the fermented liquid 20 in the chamber 131 that is considered to be optimal when causing the siphon effect. What is necessary is just to match | combine with the liquid level 20A.

  The baffle plate 119A guides the fermented liquid 20 flowing from the lower side to the upper side of the chamber 132 in the X-axis positive direction, and passes the fermented liquid 20 flowing from the chamber 133 to the chamber 132 through the upper side of the partition wall 116. It is provided to guide to the negative direction side.

  Next, the process in which biogas is produced in the biogas generator 100 will be described with reference to FIGS. 3 and 4.

  FIG. 3 and FIG. 4 are diagrams showing the steps in which the biogas generation apparatus 100 generates biogas step by step.

  In the stage immediately before the biogas production process starts, the liquid level 20A of the fermentation liquid 20 in the chamber 131 is substantially equal to the height of the end portion 118A of the U-shaped tube 118, as shown in FIG. The state shown in FIG. 3 (A) is the same as the state shown in FIG. 1. As an example, the liquid surface 20B and the liquid surface 20A have the same height, and in this state, the fermentation liquid 20 inside the chamber 131, The balance (balance) with the fermentation liquid 20 inside the chambers 132 to 134 is taken.

  In the state shown in FIG. 3A, the fermentation liquid 20 in the chambers 131 to 134 starts to generate biogas, and the biogas starts to be stored in the upper portion of the chamber 131. Thereby, the amount of biogas stored in the sealed space above the liquid level 20A of the fermentation liquid 20 in the chamber 131 gradually increases. As the biogas is generated, the space above the liquid level 20B of the chambers 132 to 134 is in an anaerobic state where no oxygen is present. The biogas generated in the chambers 132 to 134 is discharged from the discharge port 113A.

  When the amount of biogas increases in the upper part of the chamber 131, as shown in FIG. 3 (B), the liquid level 20A of the fermentation liquid 20 in the chamber 131 is gradually pushed down, and the fermentation liquid 20 in the chamber 131 opens the slit 115C. To move to the chamber 132 as indicated by an arrow B1.

  Further, since the chambers 132 and 133 communicate with each other at the upper part of the partition wall 116 and the chambers 133 and 134 communicate with each other at the bottom through the slit 117C, the fermentation broth 20 is indicated by arrows B2 and B3. , Flows into the chambers 133 and 134 from the chamber 132.

  As a result, as shown in FIG. 3B, the liquid level 20B of the fermentation liquid 20 in the chambers 132, 133, and 134 is pushed up.

  As described above, when the fermentation liquid 20 in the fermenter 130 generates biogas and the liquid level 20A of the fermentation liquid 20 in the chamber 131 is pushed down, the fermentation liquid 20 moves from the chamber 131 toward the chamber 134.

  When biogas is further generated inside the fermenter 130 and the liquid level 20A of the fermentation liquid 20 in the chamber 131 is pushed down to the bottom of the middle part 118C of the U-shaped tube 118 as shown in FIG. A siphon effect occurs through the tube 118.

  FIG. 4A shows a state immediately before the siphon effect occurs. As indicated by arrows C1, C2, and C3, the fermentation liquor 20 flows from the chamber 131 toward the 134.

  The siphon effect occurs when the liquid level 20 </ b> A of the fermentation liquid 20 in the chamber 131 is pushed down to the bottom of the intermediate part 118 </ b> C of the U-shaped pipe 118.

  When the siphon effect occurs, as shown in FIG. 4B, the biogas stored in the upper part of the chamber 131 goes out to the chamber 132 through the U-shaped tube 118. At this time, the fermentation broth 20 in the chambers 132 to 134 flows in the direction toward the chamber 131 as indicated by arrows D2 and D3, and returns from the chamber 132 to the chamber 131 via the slit 115C as indicated by the arrow D1. come. The change from the state of FIG. 4A to the state of FIG. 4B is completed in about several seconds.

  At this time, the water flow (arrow D1) of the fermentation broth 20 that rapidly returns from the chamber 132 to the chamber 131 through the slit 115C passes through the front of the slit 114B (X-axis positive direction side) and rises inside the chamber 131. To do.

  For this reason, the water pressure in the space in front of the slit 114B (in front of the X axis positive direction side) is lower than the water pressure in other portions. That is, a state in which a negative pressure is generated is obtained.

  Therefore, the substrate 10 containing a large amount of biomass material that precipitates at the bottom of the pretreatment tank 120 flows out into the chamber 131 through the slit 114B.

  In addition, since the change from the state of FIG. 4A to the state of FIG. 4B is completed in about several seconds, the water flow represented by the arrows D1 to D3 is a water flow that occurs abruptly, and FIG. ) And the water flow represented by arrows B1 to B3 and arrows C1 to C3 in FIG.

  Further, inside the chambers 132, 133, and 134, as shown by broken arrows E1, E2, and E3, a water flow that vortexes due to an abrupt water flow also occurs.

  For this reason, the fermentation liquid 20 in the chambers 131 to 134 is agitated as a whole by the water flow represented by the arrows D1 to D3 and the water flow that winds the vortices indicated by the broken arrows E1, E2, and E3. Thereby, the density | concentration (concentration of biomass raw material) of the fermentation liquid 20 of the chambers 131-134 is equalized.

  From the state shown in FIG. 4 (B), the liquid level 20A of the fermentation liquid 20 in the chamber 131 and the liquid level 20B of the fermentation liquid 20 in the chambers 132 to 134 are balanced from the chamber 132 to the chamber 131 through the slit 115C. While the fermentation liquid 20 moves and the substrate 10 is replenished inside the chamber 131, the liquid level 20A of the fermentation liquid 20 inside the chamber 131 rises. Moreover, the fermentation broth 20 of the chambers 131-134 is stirred as a whole, and the density | concentration (concentration of biomass raw material) of the fermentation broth 20 is equalized.

  And if the liquid level 20A of the fermentation liquid 20 of the chamber 131 and the liquid level 20B of the fermentation liquid 20 of the chambers 132-134 balance, it will return to the state shown to FIG. 3 (A).

  And in the state shown to FIG. 3 (A), the fermented liquid 20 of the chambers 131-134 produces | generates biogas, and after that FIG. 3 (B), FIG. 4 (A), and FIG. ) Is repeated.

  In this way, the biogas generation apparatus 100 continues to generate biogas. The biogas is discharged to the outside of the biogas generator 100 through the discharge port 113A. Further, when the substrate 10 containing a large amount of biomass raw material that precipitates at the bottom of the pretreatment tank 120 flows out into the chamber 131 through the slit 114B, the same amount as the substrate 10 supplied from the pretreatment tank 120 to the fermentation tank 130. The fermented liquor 20 is discharged from the discharge port 112F and further discharged to a drainage facility (not shown).

  As described above, according to the biogas generator 100, the fermentation gas 20 in the fermenter 130 can be stirred without power using the biogas stored in the upper part of the chamber 131 of the siphon type fermenter 130, and the The substrate 10 can be supplied from the pretreatment tank 120 to the fermenter by power.

  Next, the merit of the biogas generator 100 will be described with reference to FIGS. 5 and 6.

  FIG. 5 is a diagram showing a general methane fermentation system 500. Here, first, a general methane fermentation system 500 will be described, and then, merits when the biogas generator 100 is applied to the general methane fermentation system 500 will be described.

  As an example, the methane fermentation system 500 is provided in a facility such as a plant, and generates biogas using a biomass raw material.

  The methane fermentation system 500 includes a crusher 501, a raw material charging pump 502, a pretreatment tank 503, a pretreatment tank stirring pump 504, a substrate charging pump 505, a fermentation tank 506, a fermentation tank stirring pump 507, a hot water circulation pump 508, and a stirring blower 509. , A gas storage tank 510, a pressure fan 511, and a drainage pump 512.

  Biomass raw materials such as food residues crushed by the crusher 501 are supplied to the pretreatment tank 503 by the raw material input pump 502 and diluted with water to generate a slurry (substrate) containing the biomass raw material. The slurry in the pretreatment tank 503 is agitated by a pretreatment tank agitation pump 504.

  The biomass material precipitated in the pretreatment tank 503 is supplied to the fermentation tank 506 by the substrate charging pump 505. The fermentation liquor stored in the fermenter 506 is agitated by a fermenter agitation pump 507 and at a temperature suitable for fermentation by a hot water circulation pump 508 (for example, a temperature in the range of 30 ° C. to 60 ° C., for example, 35 Degree or 55 degrees) and further stirred by the stirring blower 509.

  Biogas generated in the fermenter 506 is stored in the gas storage tank 510 and supplied to the gas engine by the pressurized fan 511 as an example. Further, the fermented liquid that is no longer necessary in the fermenter 506 is discharged to the drainage facility by the drainage pump 512.

  The electric power generated by the gas engine is taken out as recovered electric power, a part is consumed as electric power (power consumption) necessary for the methane fermentation system 500, and surplus electric power (excess electric power) is installed in the methane fermentation system 500. Can be used in other plants.

  The power consumption includes, for example, the crusher 501 of the methane fermentation system 500, the raw material charging pump 502, the pretreatment tank stirring pump 504, the substrate charging pump 505, the fermentation tank stirring pump 507, the hot water circulation pump 508, the stirring blower 509, Electric power used to drive the pressure fan 511 and the drain pump 512.

  Further, the heat generated by the gas engine is taken out as recovered exhaust heat, and part of the heat is used as heat (consumed heat) necessary for the methane fermentation system 500, and surplus heat (surplus heat) is used as the methane fermentation system 500. It can be used in a plant or the like where is installed.

  In addition, heat consumption is the heat utilized when warming a fermentation liquid with the hot water circulation pump 508 of the methane fermentation system 500, for example.

  Here, when the biogas generator 100 according to the embodiment is applied to the methane fermentation system 500 shown in FIG. 5, power consumption can be reduced as follows.

  First, the biogas generator 100 integrates the pretreatment tank 120 and the fermenter 130 and communicates them with the slit 114B, and uses the water flow generated by the siphon effect, from the pretreatment tank 120 via the slit 114B. The substrate 10 is supplied to the fermenter 130.

  In the methane fermentation system 500 shown in FIG. 5, the pretreatment tank 503 and the fermentation tank 506 are integrated.

  For this reason, if the biogas generator 100 of embodiment is applied to the methane fermentation system 500 shown in FIG. 5, the substrate injection | pouring pump 505 will become unnecessary.

  Moreover, the biogas generator 100 is stirring the fermented liquid 20 using the water flow produced inside the fermenter 130. This corresponds to the roles of the fermenter stirring pump 507 and the stirring blower 509 connected to the fermenter 506 in the methane fermentation system 500 shown in FIG.

  For this reason, if the biogas generator 100 of embodiment is applied to the methane fermentation system 500 shown in FIG. 5, the fermenter stirring pump 507 and the stirring blower 509 will become unnecessary.

  As described above, when the biogas generator 100 according to the embodiment is applied to the methane fermentation system 500 shown in FIG. 5, the substrate charging pump 505, the fermenter stirring pump 507, and the stirring blower 509 are not necessary.

  Therefore, when the biogas generator 100 is applied to the methane fermentation system 500 as shown in FIG. 5, the energy recovery efficiency can be improved by reducing the power consumption.

  FIG. 6 is a diagram showing a power balance. The horizontal axis indicates the amount of food residue (t / day). The amount of food residue (t / day) represents the amount of food residue introduced into the crusher 501 shown in FIG. 5 in tons per day. The vertical axis represents the power ratio obtained by dividing the power consumption by the recovered power amount in percentage (%).

  Moreover, A (marker of (circle)) shows the power ratio by the methane fermentation system 500 shown in FIG. As described above, the methane fermentation system 500 shown in FIG. Electric power is required to operate the pressure fan 511 and the drain pump 512.

  B (marker of Δ) indicates a power ratio by a system in which the pretreatment tank 503 and the fermentation tank 506 are integrated in the methane fermentation system 500 shown in FIG. 5 and the pretreatment tank agitation pump 504 is omitted. That is, the power consumption of the system B is lower than the power consumption of the system A by the amount that the pretreatment tank agitation pump 504 is omitted.

  C (marker of □) shows a power ratio obtained by a system in which the fermenter 506 is a siphon type in the methane fermentation system 500 shown in FIG. 5 and the fermenter agitation pump 507 and the agitation blower 509 are omitted. Note that the pretreatment tank 503 and the fermenter 506 are not integrated.

  That is, the power consumption of the C system is lower than the power consumption of the A system by eliminating the fermenter agitation pump 507 and the agitation blower 509.

  D (marker of ◇) saves the substrate charging pump 505, the fermenter stirring pump 507, and the stirring blower 509 by applying the biogas generator 100 of the embodiment to the methane fermentation system 500 shown in FIG. It shows the power ratio by the system.

  That is, the power consumption of the system D is lower than the power consumption of the system A by the amount that omits the substrate charging pump 505, the fermenter stirring pump 507, and the stirring blower 509.

  As shown in FIG. 6, it can be seen that in any of the systems A to D, the power ratio tends to decrease as the amount of food residue increases. This is because the energy recovery efficiency is improved by increasing the amount of food residue.

  However, in the systems A and B, even if the amount of food residue is increased to 1 (t / day), the power ratio is 130% and 126%, respectively, and the power consumption exceeds the recovered power amount. I understand. In this case, in order to obtain renewable energy from biomass raw material, more electric power is consumed than recoverable renewable energy, and the power balance is negative.

  In the C and D system, when the amount of food residue is about 0.25 (t / day) or more, the power ratio is about 100% or less.

  More specifically, in the C and D systems, when the amount of food residue is 0.3 (t / day), the power ratio is 75% and 70%, respectively. When the amount of food residue is 0.6 (t / day), the power ratio is 57% and 53%, respectively. When the amount of food residue is 1 (t / day), the power ratio is 48% and 44%, respectively.

  From the above, it can be seen that the power ratio of the system D is improved by about 5% compared to the system C.

  Therefore, the biogas generator 100 of the embodiment uses the biogas stored in the upper part of the chamber 131 of the siphon-type fermenter 130 to stir the fermentation liquid 20 in the fermenter 130 without power, By supplying the substrate 10 from the pretreatment tank 120 to the fermentation tank, the energy recovery efficiency (regeneration efficiency) can be improved.

  Therefore, according to the embodiment, it is possible to provide the biogas generator 100 with high energy recovery efficiency.

  In addition, although the above demonstrated the form in which the pretreatment tank 120 and the fermenter 130 were partitioned by the partition plate 114 in the treatment tank 110 in which the pretreatment tank 120 and the fermentation tank 130 were integrated, the pretreatment The tank 120 and the fermenter 130 may be separated from each other. Instead of the slit 114B, a flow path connecting the opening provided in the lower part of the pretreatment tank 120 and the raw material inlet provided in the lower part of the fermenter 130 is provided, and the biomass raw material precipitated to the inside of the flow path It may be filled.

  Moreover, although the slit 114B demonstrated the form formed between the bottom plate 111 of the pretreatment tank 120 and the fermenter 130, and the lower end 114A of the partition plate 114 in the above, the position of the slit 114B is a little more than the bottom plate 111. It may be in a high position.

  Moreover, although the fermenter 130 demonstrated the form which has the four chambers 131-134 above, the fermenter 130 does not need to have the chamber 134. FIG. In this case, a discharge port 112F may be provided in the chamber 133. In addition, the fermenter 130 may not have the chambers 133 and 134. In this case, a discharge port 112F may be provided in the chamber 132. Moreover, the fermenter 130 may have five or more chambers.

  Further, the discharge port 113A for discharging the biogas may be attached anywhere as long as it is between the partition wall 115 and the partition plate 119B in the X-axis direction.

  The biogas generation apparatus according to the exemplary embodiment of the present invention has been described above, but the present invention is not limited to the specifically disclosed embodiment, and departs from the scope of the claims. Various modifications and changes are possible.

DESCRIPTION OF SYMBOLS 10 Substrate 10A Liquid level 20 Fermentation liquid 20A, 20B Liquid level 100 Biogas generator 110 Processing tank 111 Bottom plate 112, 112A, 112B, 112C, 112D Side wall 112F Discharge port 113 Top plate 113A Discharge port 114 Partition plate 114B Slit 115, 116 117 partition wall 115B through hole 118 U-shaped pipe 118A, 118B end 118C intermediate part 119A baffle plate 119B partition plate 119C partition board 120 pretreatment tank 130 fermenter

Claims (5)

A pretreatment tank for precipitating biomass raw material in water, and a pretreatment tank having an opening at the bottom;
A siphon-type fermenter that stores the fermentation liquid containing the biomass raw material supplied through the opening of the pretreatment tank in the presence of microorganisms to generate biogas,
The fermenter is
A raw material charging port provided at a lower portion of the fermenter and connected to the opening;
An exhaust port provided at the top of the fermenter at a position spaced apart from the raw material input port in plan view, and discharging the biogas;
In a position between the raw material inlet and the outlet in a plan view, it extends from the top plate of the fermenter to a first height position before a first predetermined distance of the bottom plate inside the fermenter and penetrates. A first partition having a hole, wherein a space above the through-hole is sealed, and a first tank in which the raw material charging port is provided at a lower portion; A first partition that communicates and divides the internal space of the fermenter into a second tank provided with the discharge port at the top;
A U-shaped tube having a first end and a second end, inserted into the through-hole of the first partition wall at an intermediate portion between the first end and the second end, with respect to the intermediate portion; A biogas generator, comprising: a U-shaped tube with the first end and the second end extending upward. The pretreatment tank and the fermentation tank are integrally formed,
It extends from the top plate of the pretreatment tank and the fermenter to a second height position before a second predetermined distance of the bottom plate, and the opening and the raw material are charged in a space below the second height position. The biogas generator according to claim 1, further comprising a partition plate for constructing the mouth. The level of the fermentation liquid in the first tank is pushed down by the biogas stored in the upper part of the first tank, and the fermentation liquid in the first tank moves into the second tank and moves to the second tank. The liquid level of the fermentation liquid in the tank is pushed up,
When the liquid level of the fermentation broth in the first tank is pushed down to the middle part of the U-shaped tube, due to the siphon effect through the U-shaped tube, the liquid level of the fermentation liquid in the first tank, and The biogas generator according to claim 1 or 2, wherein the fermented liquid moves from the second tank to the first tank until the liquid level of the fermented liquid in the second tank is balanced.   When the fermentation liquid moves from the second tank to the first tank due to the siphon effect, the biomass raw material is supplied from the opening of the pretreatment tank to the raw material inlet of the first tank. Item 4. The biogas generator according to Item 3.   The biogas generator according to any one of claims 1 to 4, wherein the fermenter further includes one or a plurality of second partition walls that divide the second tank into a plurality of tanks.