KR101951875B1 - Apparatus for anaerobic disgestion with two phase separation type - Google Patents

Abstract

The present invention relates to a two-phase separation type anaerobic digestion apparatus, which comprises an acid fermentation treatment unit for treating organic wastes with acid-producing bacteria, a methane fermentation treatment unit for separating organic wastes from the acid fermentation treatment unit, And a digester filtrate storage unit connected to the methane fermentation processor and connected to the methane fermentation processor for transferring and storing digestion filtrate. Therefore, the present invention maintains optimal microorganism habitat condition of each fermentation tank through complete separation of acid fermentation tank and methane fermentation tank by two-phase separation type anaerobic digestion, thereby maintaining the optimum population of acid-producing bacteria and methanogenic bacteria in the digestion tank, Treatment and biogas increase, it is possible to provide stable operation of the facility and economical facility operation.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a two-phase separated anaerobic digestion apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-phase separation type anaerobic digestion apparatus, and more particularly, to a two-phase separation type anaerobic digestion apparatus in which organic wastes are anaerobically digested by separating two phases of an acid fermentation treatment tank and a methane fermentation treatment tank.

Recently, anaerobic digestion facilities for organic wastes such as food wastes, sewage sludge and livestock manure are not only a land treatment method emerging as an alternative to the prohibition of marine dumping, but also a new renewable An organic waste anaerobic digestion facility, which produces biogas through anaerobic digestion of organic wastes and utilizes it as an alternative energy source for LNG, is an interest in the facility that produces energy sources. With the efforts of the government and local governments, .

However, such a conventional anaerobic digestion treatment apparatus has not yet been high in terms of the total facility utilization rate due to low facility operation and organic matter removal rate due to insufficient facilities to be installed in the following anaerobic digestion system.

In the existing anaerobic digestion system, the operation of the facility is affected by the design and construction without consideration of the following points.

First, the different microorganism habitat environmental conditions of acid fermentation and methane fermentation by adopting the single phase method are frequently encountered in the abnormal treatment of organic matter due to the difficulty in maintaining the optimal state of microorganisms in one reactor, Lt; / RTI >

Secondly, when the digester agitation method in the methane fermentation tank is not stirred due to gas agitation, external circulation pump method or gas pressure, due to improper agitation method, the agitation of the digester can not be performed and the microbial and substrate layer separation and the microbial degradation The biogas production efficiency is lowered.

Third, when the scum removing device and the lower foreign material removing device on the methane fermentation tank are not installed, the upper scum blocks the generation of the biogas generated in the methane fermentation tank, thereby increasing the H ₂ partial pressure, In the case of not removing the lower foreign matter, the dead space of the methane fermentation tank is increased. As a result, the residence time of the methane fermentation tank is shortened and the organic matter A problem that is not normally handled occurs.

Fourth, the over-flow phenomenon occurs when the digester is in abnormal operation. If the over-flow facility is not installed for such a phenomenon, the anaerobic digestion liquid contained in the methane fermentation tank is fed through the biogas feed duct The entire facility is shut down due to contamination of the biogas refinery by being transported to the biogas refinery (water removal facility, desulfurization facility, siloxane removal facility) at the downstream of the digester.

Fifth, when the H ₂ S concentration is higher than 3,000 ppm, H ₂ S toxicity inhibits the growth of anaerobic microorganisms (methanogenic bacteria), so that the H ₂ S concentration in the methane fermentation tank should be maintained below 3,000 ppm.

Thus, the conventional anaerobic digestion facilities are not equipped with appropriate facilities capable of coping with the above five important matters (single phase digestion, stirring method, scum and foreign matter generation, over-flow phenomenon, high concentration H2S occurrence) , There is a problem that the organic matter, which is a core function of the digester, is not appropriately treated due to abnormal operation of the digester.

Korean Patent No. 10-0782960 (December 11, 2007) Korean Patent Publication No. 10-2012-0124703 (November 14, 2012) Korean Patent No. 10-1286072 (July 15, 2013)

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the above-mentioned conventional problems, and it is an object of the present invention to provide a digestion tank capable of maintaining an optimal population of acid-producing bacteria and methanogenic bacteria in a digester, The present invention also provides a two-phase separation type anaerobic digestion device.

In addition, the present invention can maintain the concentration of H ₂ S at less than 10 ppm by installing a dry desulfurization facility only when the desulfurization treatment is first performed in the digester, Another object of the present invention is to provide a two-phase detachable anaerobic digestion device capable of securing the anaerobic digester.

It is another object of the present invention to provide a two-phase separation type anaerobic digestion apparatus capable of increasing the contact time and contact efficiency between an input substrate and a microorganism through a complete mixing induction in a digestion tank, thereby improving an organic matter decomposition rate.

In addition, the present invention provides a scum removal facility on the upper part of the methane fermentation tank to remove the scum precursors and operate the digester unilaterally, while a cyclone for removing sediment is installed under the digester to remove periodic sediments, It is another object of the present invention to provide a two-phase separation type anaerobic digestion apparatus capable of stable operation of a digester by securing a sufficient residence time by returning the digester to a digestion tank.

It is another object of the present invention to provide a two-phase separation type anaerobic digestion device capable of removing a scum-generating precursor in advance and discharging a digestion filtrate in advance in preparation for a tide overflow phenomenon.

To achieve the above object, the present invention provides an acid fermentation treatment unit 10 for treating organic wastes with acid-producing bacteria; A methane fermentation processor 20 connected to the downstream of the acid fermentation processor 10 to treat the organic waste by methanogenic bacteria; And a digestive filtrate storage unit 30 connected to the methane fermentation processing unit 20 downstream of the methane fermentation processing unit 20 to transport and store the digested filtrate.

The present invention is further characterized in that the present invention further comprises a drug charging unit 40 installed upstream of the methane fermentation treatment unit 20 and injecting ferric chloride (FeCl ₃ ) into the methane fermentation treatment unit 20 .

The medicament charging unit 40 of the present invention includes a drug reservoir for storing ferric chloride (FeCl ₃ ); A chemical stirrer installed to rotate on a vertical axis at the top of the medicine reservoir, for stirring the drug; And a chemical feed pump connected to a lower portion of the chemical reservoir to pump the chemical to be transferred.

The present invention further includes a biogas processing unit 50 connected to the methane fermentation processing unit 20 to process the biogas discharged from the methane fermentation processing unit 20.

The biogas treatment unit (50) of the present invention comprises a water removal facility for removing moisture contained in the biogas; Dry desulfurization equipment to remove sulfur components contained in biogas; And a siloxane removing equipment for removing the siloxane contained in the biogas.

The methane fermentation processing unit (20) of the present invention comprises a methane fermentation tank for digesting organic wastes with methanogenic bacteria; A methane fermentation stirrer installed at an upper portion of the methane fermentation tank and configured to rotate based on a vertical axis; A baffle disposed inside the methane fermentation tank and forming a turbulent flow to suspend the precipitate when the methane fermentation stirrer is stirred; A contaminant transporting facility installed on an inner bottom of the methane fermentation tank for discharging contaminants on the bottom to the outside; And a cyclone disposed downstream of the contaminant transporting facility for separating the discharged contaminants into solid-liquid.

The methane fermentation processing unit 20 of the present invention further includes a scum removing facility installed on the methane fermentation tank to remove scum.

The digestion filtrate storage unit 30 of the present invention includes a digestion filtrate storage tank for storing the digestion filtrate that has been overflowed in the methane fermentation processing unit 20; And a digestive filtrate transfer facility installed between the methane fermentation processing unit 20 and the digestion filtrate storage unit to open the valve only when the internal pressure of the methane fermentation processing unit 20 is within a predetermined range, .

As described above, the present invention maintains optimal microbial habitat condition of each fermentation tank by completely separating acid fermentation tank and methane fermentation tank by two-phase separation type anaerobic digestion, thereby maintaining the optimum population of acid- and methanogenic bacteria in digestion tank And at the same time, it can provide stable operation of the facility and economical facility operation through proper treatment of organic matter and increase of biogas.

In addition, when the desulfurization treatment is performed in the first digestion tank through the connection of the chemical feed section and the biogas processing section to the methane fermentation treatment section, the concentration of H ₂ S can be maintained at 10 ppm or less by only installing the dry desulfurization facility, When installing power generation facilities, stable operation is possible and economical efficiency of desulfurization facilities can be secured.

Also, by providing a mechanical vertical-type agitator and a baffle in the methane fermentation tank, it is possible to improve the decomposition rate of organic matter by increasing the contact time and contact efficiency between the input substrate and the microorganism through complete mixing induction in the digester.

In addition, a scum removal facility is installed on the upper part of the methane fermentation tank to remove the scum precursors and operate the digester unilaterally. At the same time, a cyclone for removing sediment is installed at the bottom of the digester to remove periodic sediment and return the microorganisms to the digester Thereby providing a stable digestion tank operation by securing sufficient residence time.

In addition, by operating the scum removing device and the extinguishing filtrate transferring device in parallel, the scum generating precursor is removed in advance, and at the same time, the digesting filtrate can be discharged in advance in preparation for the overflowing phenomenon.

1 is a view showing a two-phase separation type anaerobic digestion apparatus according to an embodiment of the present invention;
2 is a graph showing a state before and after the introduction of a drug in a two-phase separation type anaerobic digestion apparatus according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a view showing a two-phase separation type anaerobic digestion apparatus according to an embodiment of the present invention, and FIG. 2 is a graph showing a state before and after the introduction of a drug in a two- phase separation type anaerobic digestion apparatus according to an embodiment of the present invention .

1, the two-phase separation type anaerobic digestion apparatus according to the present embodiment includes an acid fermentation processing section 10, a methane fermentation processing section 20, a digestion filtrate storage section 30, a drug input section 40, And a gas treatment unit 50. The organic waste is anaerobically separated from the acid fermentation treatment tank and the methane fermentation treatment tank in two phases.

The acid fermentation processing section 10 is an acid fermentation processing means for treating organic wastes with acid-producing bacteria and is composed of an acid fermentation tank 11, an acid fermentation stirrer 12 and a discharge pump 13, The wastes are treated by a pretreatment process suitable for each substrate and then put into an acid fermentation treatment.

In the acid fermentation tank 11, the organic waste of the polymer substance such as carbohydrate, fat and protein is extracted from various microorganisms (Bacteroides, Clostridia, Bifido bacteria, etc.) by extra cellular enzymes (Hydrolases) Is decomposed while being stirred by an acid fermentation stirrer (12), which is a low molecular substance such as a monosaccharide, a fatty acid, an amino acid and the like, which is easy to use and installed in a vertical mouth type stirrer of a mechanical stirring system.

Afterwards, a variety of acid-producing bacteria (Clostridium, Peptococcus anaerobus, etc.) used soluble organic substances generated in the hydrolysis step as energy and carbon source, and various volatile fatty acids (acetic, propionic, butyric, caproic acid and the like) and low-molecular volatile organic acid which is an alcohol oxide are produced and discharged to the methane fermentation processing unit 20 through the discharge pump 13.

An acid fermentation stirrer 12 composed of a mechanical stirrer type vertical stirring type stirrer is installed on the upper part of the acid fermentation tank 11 so that the rotation intensity is changed according to the total solid concentration of the substrate TS. It is preferable that organic wastes, microorganisms, acid-producing bacteria and the like are treated while being stirred together.

The methane fermentation processing unit 20 is connected to the downstream of the acid fermentation processing unit 10 and is separated into methane fermentation processing means for treating organic wastes with methanogenic bacteria. The methane fermentation processing unit 20 includes a methane fermentation tank 21, a methane fermentation stirrer 22, Bubble 23, contaminant transfer facility 24, transfer pump 25, cyclone 26, recovery pipe 27, scum removal facility 28 and trolley overtransport facility 29.

Methane fermentation tank 21 is a methane fermentation means for digesting organic wastes with methane-producing bacteria. The methane fermentation tank 21 is a methane fermentation means for digesting organic wastes with methane-producing bacteria (Methanobacterium, Methanosarcina, Methanospirillum etc.) from low molecular volatile organic acids produced through an acid fermentation tank 11 ₄ and CO ₂ .

The methane fermentation stirrer 22 is a stirrer provided on the upper portion of the methane fermentation tank 21 and provided so as to rotate with respect to the vertical axis. The methane fermentation stirrer 22 is composed of a vertical-mouth type stirrer of mechanical stirring type, And it is preferable that organic wastes, microorganisms, and methanogenic bacteria are treated in the methane fermentation tank 21 while being stirred together.

The baffle 23 is provided around the inside of the methane fermentation tank 21 and forms a turbulent flow so as to flocculate the sediment during agitation of the methane fermentation stirrer 22. The baffle 23 is provided inside the methane fermentation tank 21 So that the contact force between the methane-producing bacteria and the organic matter is enhanced by the operation of the vertical inlet-type methane fermentation stirrer 22.

Therefore, there is a problem in that it is difficult to operate the digester such as separation of microorganism and substrate in the methane fermentation tank 21, generation of scum and bubbles, difficulty in maintaining the temperature difference between the digester and the dead space, The cause of the problem is removed in advance.

The contaminant transfer facility 24 is a contaminant transfer facility installed on the inner bottom of the methane fermentation tank 21 and discharging the contaminants deposited on the bottom to the outside. The bottom bottom slope of the methane fermentation tank 21 is installed at an angle of 1/12 or more When the methane fermentation stirrer 22 is operated, the impurities having a large specific gravity are transferred to the center bottom of the digester. Then, the impurities are transferred to the outside according to the operation of the transfer pump 25 through the impurity suction pipe located at the center of the lower portion of the methane fermentation tank.

The cyclone 26 is a separating means provided downstream of the impurity conveying facility 24 for separating the impurities discharged from the impurity conveying facility 24 into solid-liquid components. The liquid component is supplied to the methane fermentation tank 21, and the solid-phase component is discharged to the extinguishing filtrate storage unit 30 and discarded.

The scum removing facility 28 is a scum removing means installed on the upper part of the methane fermentation tank 21 to remove scum. In order to prevent the digestion tank overflow phenomenon in advance, A scum removing unit and a scum transfer pump are installed to remove oil, FS, and scum in advance, thereby preventing the overflowing of the methane fermentation tank 21 primarily.

The trough overflow conveying facility 29 is provided on the upper part of the methane fermentation tank 21 and serves as a second means for delivering the extinguished filtrate to the outside when the trough is overflowed. And is safely transferred to the extinguishing filtrate storage unit 30.

The trough overflow conveying facility 29 is composed of a discharge pipe having a diameter of about 500 mm and a spacing of about 300 mm from the upper water surface of the methane fermentation tank 21 and spaced about 300 mm from the inner wall of the methane fermentation tank 21 have.

In particular, an outlet valve connected to the lower portion of the methane fermentation tank 21 is provided with an automatic valve and normally closed. When the pressure of the methane fermentation tank 21 is 400 mmAq or more, the automatic valve is opened, When the pressure of the methane fermentation tank 21 is 500 mmAq, the biogas piping is closed to prevent the digested filtrate from being transferred to the biogas purification facility through the biogas piping when the tide overflow occurs, And is sent to the extinguished filtrate storage unit 30 through the conduit 29 to safely operate the methane fermentation tank 21.

Therefore, in the case of the conventional digester, there is no countermeasure against the over-flow phenomenon of the digester trough due to the scum removing facility 28 and the trough overflow conveying facility 29, When the biogas is refined at the downstream of the digester, the problem that the downstream biogas utilization facility including the purification facility can not be used due to contamination of the purification facility is solved.

In particular, the overflow phenomenon is caused by the fact that the biogas generated in the digester is not discharged smoothly due to the scum generated by the combined oil and FS components in the digester, And the digestion filtrate are simultaneously raised and discharged to the downstream biogas purification facility through the biogas piping. The fundamental cause of this phenomenon is the inclusion of the oil and the FS components introduced into the substrate to form a film on the digester. Is solved in the present invention.

Since the acid fermentation tank 11 and the methane fermentation tank 21 are operated separately from each other, the two-phase separation type anaerobic digestion apparatus of the present invention can be used for a variety of microorganisms such as acidification and methanogenesis, It is possible to efficiently decompose organic substances and maintain a stable anaerobic digestion system.

The digestion filtrate storage unit 30 is connected to the downstream of the methane fermentation processing unit 20 and stores the digestion filtrate when the digestion filtrate is overflowed in the methane fermentation processing unit 20. The digestion filtrate storage unit 31, A filtrate agitator 32 and an extinguishing filtrate transfer facility 33.

The digestion filtrate storage tank 31 stores a digestion filtrate stored in the methane fermentation processing unit 20 and stores the digested filtrate at the upper portion of the methane fermentation tank 21 through the overflow conveyance facility 29 .

The digestion filtrate agitator 32 is provided on the upper portion of the extinguishing filtrate storage tank 31 so as to rotate by a vertical axis and stirs the extinguishing filtrate. The digestion filtrate agitator 32 is composed of a vertical-mouth type stirrer of mechanical stirring type, it is preferable to change it depending on the total solid concentration.

The extinguishing filtrate transfer facility 33 is a transfer means provided between the methane fermentation processing unit 20 and the extinguishing filtrate reservoir 31. When the internal pressure of the methane fermentation processing unit 20 is within a predetermined range, The filtrate is transferred.

The chemical feed section 40 is provided upstream of the methane fermentation processing section 20 and is a chemical feed means for feeding ferric chloride (FeCl ₃ ) into the methane fermentation processing section 20. The chemical feed section 40 includes a chemical reservoir 41, a chemical stirrer 42 And a chemical feed pump 43. [0050]

The chemical storage tank 41 is a storage means for storing chemicals for removing H ₂ S at a high concentration of 3,000 ppm or more in the methane fermentation processing unit 20. The storage tank 41 is made of ferric chloride (FeCl ₃ ) so as to add ferric chloride (FeCl ₃ ) .

The chemical stirrer 42 is a stirrer for stirring the medicine, which is installed on the upper side of the medicine reservoir 41 to rotate by a vertical axis. The drug stirrer 42 is composed of a vertical-mouth type stirrer of mechanical stirring type, It is preferable to change it according to the concentration.

The chemical feed pump 43 is connected to a lower portion of the chemical reservoir 41 and pumped so as to feed the chemical. The chemical feed pump 43 pumps the ferric chloride (FeCl ₃ ) to feed ferric chloride (FeCl ₃ ) .

The biogas processing unit 50 is biogas processing means connected to the downstream of the methane fermentation processing unit 20 for processing the biogas discharged from the methane fermentation processing unit 20 and includes a water removal facility 51, 52 and a siloxane removal facility 53.

The water removal facility 51 removes moisture contained in the biogas and removes moisture from the biogas discharged through the gas pipe connected to the upper portion of the methane fermentation tank 21.

The desulfurization facility 52 is connected to the downstream of the water removal facility 51 to remove sulfur components from the biogas from which moisture has been removed from the water removal facility 51 do.

The siloxane removal facility 53 is connected to the downstream of the dry desulfurization facility 52 to remove the siloxane from the biogas in which the sulfur content has been removed from the dry desulfurization facility 52 do.

The organic acid produced through the digestion process of the acid fermentation tank 11 is decomposed in the methane fermentation tank 21 by the action of the methanogenic bacteria and biogas is generated and the anaerobic digestion of the anaerobic digestion H ₂ S at a concentration of 3,000 ppm or more will be generated inside the biogas generated from the digestion facility.

The methane fermentation tank 21 containing the high concentration of H ₂ S acts as a toxic agent of methanogenic bacteria and acts as a factor for lowering the activity. In order to utilize the produced biogas for power generation, etc., However, in the case of dry desulfurization, desulfurization equipment can not be removed to less than 10ppm and wet desulfurization equipment must be installed. Therefore, the wet desulfurization facility has a higher initial investment cost and operating cost than the dry desulfurization facility.

Therefore, in the anaerobic digestion apparatus of the present invention, H ₂ S at a high concentration of 3,000 ppm or more is firstly removed from the methane fermentation tank 21 to 500 ppm or less and removed to 10 ppm or less from the dry desulfurization facility 52.

In order to remove H ₂ S from the methane fermentation tank 21 at a rate of 500 ppm or less, the chemical storage tank 41 and the chemical feed pump 43 are installed to inject the chemical (FeCl ₃ ) into the methane fermentation tank 21 .

In particular, the injection concentration of the FeCl ₃ is 150ppm and because the concentration of H ₂ S according to the injection amount of FeCl ₃ can be reduced and at the same time struvite (Struvite) decreased to less than 500ppm, digestion filtrate to the rear end of the methane fermenter 21 It is possible to minimize the influence of struvite generated in the storage section 30 and the dehydrator.

Therefore, when the struvite is generated, it is possible to solve the problem that the transfer pipe, the pump, and other various transfer devices are clogged and the digester can not be operated.

Ferric chloride (FeCl ₃₎ Looking at the H ₂ S and struvite removal mechanism in accordance with the input, ferric chloride charged into the methane fermentation tank (21) (FeCl ₃₎ is an iron ion dissociation (Fe ₃ ⁺⁾ and biogas sulfur ions (S ^-) and reacted iron sulfide (Fe ₂ S ₃₎ generated by removing H ₂ S, and removing struvite is the iron ions (Fe ³⁺⁾ and phosphate (PO ₄ ^3-) and iron phosphate by the reaction (FePO ₄ ), thereby preventing struvite generation by removing phosphate (PO ₄ ^3- ) as a struvite-producing substance in advance.

As described above, the H ₂ S reduction and the struvite removal are performed in the biogas in accordance with the installation and operation of the chemical storage tank 41 and the chemical feed pump 43, which are the chemicals (FeCl ₃ ) injection equipment connected to the inside of the methane fermentation tank 21. .

As shown in FIG. 2, the results of measurement of changes in H2S concentration, methane content, and biogas generation amount before and after FeCl ₃ injection in the methane fermentation tank are shown.

The organic wastes were subjected to the anaerobic digestion system of the present invention, and FeCl ₃ was introduced into the methane fermentation tank to show changes in the H2S concentration, methane content and biogas production amount before and after the addition.

Table 1 to Table 4 show the H ₂ S concentration, biogas production amount and CH ₄ content before the addition of FeCl ₃ according to the anaerobic digestion days.

Elapsed days H ₂ S concentration Biogas production (L / d) CH ₄  density
(ppm) Remarks One 1,440.8 15,915 63.4 2 16,465 3 1,326.6 15,776 4 15,642 5 1,488.4 15,077 6 15,875 63.3 7 2,228.1 16,148 8 16,008 9 1,871.4 15,643 10 15,643 11 1,335.3 16,831 63.2 12 16,773 13 1,876.0 16,354 14 16,374 15 1,904.1 15,916 16 17,063 17 1,090.0 16,725 64.6 18 16,548 19 2,364.7 12,992 20 16,873 21 2,260.2 12,461 22 14,071 64.0 23 2,260.2 17,117 24 16,564 25 2,229.6 14,535 26 15,852 27 2,984.9 16,596 28 15,810 62.3 29 2,004.4 16,032 30 16,454 31 1,591.6 16,750 32 16,235 33 1,641.4 16,364 34 16,147 63.7 35 1,568.7 16,620 36 16,513

Elapsed days H ₂ S concentration Biogas production (L / d) CH ₄  density
(ppm) Remarks 37 1,327.7 16,990 38 15,479 39 1,016.3 15,739 40 15,376 62.3 41 1,760.2 15,028 42 14,574 43 2,028.1 15,594 44 15,530 45 1,847.5 15,111 46 13,421 63.6 47 1,741.3 14,693 48 15,086 49 1,393.5 15,054 50 15,833 51 1,334.5 15,284 52 15,711 64.2 53 1,433.6 15,477 54 15,013 55 1,456.4 15,272 56 16,634 57 1,100.2 15,875 58 15,663 63.1 59 1,610.2 15,962 60 15,089 61 1,395.4 16,493 62 15,424 64.3 63 1,672.2 16,660 64 16,773 65 2,083.4 15,324 66 15,813 67 2,085.5 16,960 64.4 68 15,981 69 2,036.3 17,604 70 17,143 71 1,749.0 16,354 72 16,686 73 1,373.9 16,770 64.8 74 16,747

Elapsed days H ₂ S concentration Biogas production (L / d) CH ₄  density
(ppm) Remarks 75 1,735.1 15,913 76 17,272 77 1,688.7 16,741 78 16,871 64.3 79 2,119.2 17,507 80 15,875 81 1,804.5 16,267 82 16,928 64.4 83 1,998.3 16,161 84 15,765 85 2,000.3 16,129 86 16,810 87 2,244.1 16,459 64.8 88 16,370 89 2,124.8 16,707 90 16,857 91 2,070.9 16,825 92 2,656.9 16,148 64.5 93 2,419.7 17,584 94 1,102.4 17,147 95 1,310.1 16,825 96 935.9 16,493 97 1,144.5 17,105 98 2,004.4 16,200 99 1,591.6 16,467 64.7 100 1,641.4 16,251 101 1,568.7 16,831 102 1,327.7 16,796 103 1,016.3 17,452 104 1,760.2 16,799 64.2 105 2,028.1 16,828 106 1,847.5 17,304 107 1,741.3 16,812 108 1,393.5 17,871 109 1,334.5 17,639 110 1,433.6 18,737 63.8 111 1,456.4 18,386 112 1,100.2 17,814

Elapsed days H ₂ S concentration Biogas production (L / d) CH ₄  density
(ppm) Remarks 113 1,610.2 18,161 114 1,395.4 17,204 115 1,672.2 17,707 116 2,083.4 17,539 64.5 117 2,085.5 17,356 118 2,036.3 17,408 119 1,749.0 17,353 120 1,373.9 17,462 121 1,735.1 17,349 122 1,688.7 17,729 123 2,119.2 18,650 64.4 124 1,804.5 19,143 125 1,998.3 18,982 126 2,000.3 17,401 127 2,244.1 17,163 128 2,124.8 16,892 129 2,070.9 16,976 130 2,656.9 16,876 131 2,419.7 17,240 132 1,102.4 17,433 64.9 133 1,310.1 17,266 134 935.9 17,443 135 1,144.5 16,477

Table 5 and Table 6 below show the H ₂ S concentration, the biogas generation amount and the CH ₄ content after the addition of FeCl ₃ .

Elapsed days H ₂ S concentration Biogas production (L / d) CH ₄  density
(ppm) Remarks 136 655.2 16,899 137 808.4 16,799 66.8 138 944.5 16,606 139 17,147 140 936.0 17,848 141 563.2 15,562 142 700.9 16,469 143 754.0 17,460 66.4 144 202.2 15,987 145 199.3 16,576 65.9 146 16,342

Elapsed days H ₂ S concentration Biogas production (L / d) CH ₄  density
(ppm) Remarks 147 17,559 148 245.1 17,098 149 17,063 150 355.2 17,491 65.7 151 17,037 152 18,003 153 417.4 18,885 154 369.6 18,744 66.3 155 419.1 15,710 156 16,570 157 364.3 16,135 158 281.4 16,717 64.0 159 16,942 160 16,801 161 205.1 16,683 162 190.9 16,560 64.0 163 16,316 164 233.6 16,300

Reviews of the efficiency according to the following, FeCl ₃ In the results, experimental results for the H ₂ S concentration, biogas generation and CH ₄ content in accordance with the variation according FeCl ₃ In the methane fermentation tank in Table 7 below.

The average H ₂ S concentration decreased from 1,745.2 ppm to 412.9 ppm with FeCl ₃ , and the H ₂ S concentration reduction rate was 76.3%. The average biogas production rate was 16.843.5 L / d at 16.843.5 L / d %, And the CH ₄ content increased from 63.9% to 65.6%, an average of 2.8%.

division FeCl ₃  Before input FeCl ₃  After input Growth rate (%) H ₂ S concentration (ppm) 1,745.2 412.9 76.3 Biogas production (L / d) 15,764.0 16,843.5 6.8 CH ₄ content (%) 63.9 65.6 2.8

As described above, according to the present invention, by maintaining the optimal microorganism habitat condition of each fermentation tank by completely separating the acid fermentation tank and the methane fermentation tank by two-phase separation type anaerobic digestion, the optimum population of acid- and methanogenic bacteria in the digestion tank is maintained And at the same time, it can provide stable operation of the facility and economical facility operation through proper treatment of organic matter and increase of biogas.

In addition, when the desulfurization treatment is performed in the first digestion tank through the connection of the chemical feed section and the biogas processing section to the methane fermentation treatment section, the concentration of H ₂ S can be maintained at 10 ppm or less by only installing the dry desulfurization facility, When installing power generation facilities, stable operation is possible and economical efficiency of desulfurization facilities can be secured.

Also, by providing a mechanical vertical-type agitator and a baffle in the methane fermentation tank, it is possible to improve the decomposition rate of organic matter by increasing the contact time and contact efficiency between the input substrate and the microorganism through complete mixing induction in the digester.

In addition, a scum removal facility is installed on the upper part of the methane fermentation tank to remove the scum precursors and operate the digester unilaterally. At the same time, a cyclone for removing sediment is installed at the bottom of the digester to remove periodic sediment and return the microorganisms to the digester Thereby providing a stable digestion tank operation by securing sufficient residence time.

In addition, by operating the scum removing device and the extinguishing filtrate transferring device in parallel, the scum generating precursor is removed in advance, and at the same time, the digesting filtrate can be discharged in advance in preparation for the overflowing phenomenon.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the above embodiments are merely illustrative in all respects and should not be construed as limiting.

10: acid fermentation treatment section
20: methane fermentation processing section
30: Digestion filtrate storage unit
40:
50: Biogas processing section

Claims (8)

An acid fermentation treatment section (10) for treating organic wastes with acid-producing bacteria;
A methane fermentation processor 20 connected to the downstream of the acid fermentation processor 10 to treat the organic waste by methanogenic bacteria;
A digestive filtrate storage unit 30 connected to the methane fermentation processing unit 20 downstream of the methane fermentation processing unit 20 to store and store the digested filtrate during the overflowing of the methane fermentation processing unit 20; And
And a biogas processing unit (50) connected to the methane fermentation processing unit (20) and treating the biogas discharged from the methane fermentation processing unit (20)
The extinguishing filtrate storage unit (30)
An extinguishing filtrate reservoir storing the extinguished filtrate that has been overflowed in the methane fermentation processing unit 20;
An extinguishing filtrate agitator which is installed to rotate by a vertical axis on the upper part of the digestive filtrate storage tank and agitates the extinguished filtrate so that the rotational intensity changes according to a total solid concentration of the substrate TS; And
And a digestive filtrate transfer facility installed between the methane fermentation processing unit 20 and the digestion filtrate storage unit for opening the valve only when the internal pressure of the methane fermentation processing unit 20 is within a predetermined range, ,
The methane fermentation processing section (20)
A methane fermentation tank for digesting organic wastes with methanogenic bacteria;
A methane fermentation stirrer installed at an upper portion of the methane fermentation tank and configured to rotate based on a vertical axis;
A baffle disposed inside the methane fermentation tank and forming a turbulent flow to suspend the precipitate when the methane fermentation stirrer is stirred;
A contaminant transporting facility installed on an inner bottom of the methane fermentation tank for discharging contaminants on the bottom to the outside;
A cyclone disposed downstream of the contaminant transporting facility for separating the discharged contaminants by solid-liquid separation;
A scum removing facility installed on the upper portion of the methane fermenter to remove scum in advance to primarily prevent overflow from the methane fermenter to the biogas processor 50; And
The methane fermenter is provided at an upper portion of the methane fermenter and discharges the extinguished filtrate to the extinguishing filtrate storage portion 30 when the overflow from the methane fermenter to the biogas processor 50 is secondarily prevented An overflow conveying facility,
An automatic valve is provided in the outflow pipe connected to the lower portion of the methane fermentation tank. When the pressure of the methane fermentation tank is 400 mmAq or more, the automatic valve is opened to prevent the overflow from the methane fermentation tank to the biogas treatment unit A two-phase detachable anaerobic digester. The method according to claim 1,
Further comprising a drug input part (40) provided upstream of the methane fermentation processing part (20) for inputting ferric chloride (FeCl ₃ ) into the methane fermentation processing part (20) Device. 3. The method of claim 2,
The medicament introducing part (40)
A drug reservoir for storing ferric chloride (FeCl ₃ );
A chemical stirrer installed to rotate on a vertical axis at the top of the medicine reservoir, for stirring the drug; And
And a chemical feed pump connected to a lower portion of the chemical reservoir for pumping the chemical to be transferred. delete The method according to claim 1,
The biogas processing unit (50)
A water removal system for removing water contained in the biogas;
Dry desulfurization equipment to remove sulfur components contained in biogas; And
And a siloxane removal facility for removing the siloxane contained in the biogas. delete delete delete

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