KR101072985B1 - Appliance for producing biogas - Google Patents

Abstract

The biogas production equipment includes an anaerobic digester, a first transport pipe to return the contaminants / solids remover to remove contaminants and solids from the digestive waste discharged by the anaerobic digester, and the condensate and solids discharged from the contaminant / solids remover to the anaerobic digester. A filter for filtering the treated water discharged from the solids remover and a second conveying pipe for returning the concentrated liquid discharged from the filter to an anaerobic digester. Since the contaminants and solids in the digestive fluid flowing into the filter are largely removed in advance, the water quality of the treated water discharged from the filter is improved without deteriorating the performance of the filter. In addition, the treated water of the contaminant / solids remover and the concentrate of the filter is returned to the anaerobic digester to generate biogas through the re-extinguishing process and at the same time it is possible to secure microorganisms in the anaerobic digester.

Biogas, return, anaerobic digester, contaminants, raw materials

Description

Biogas production equipment {Appliance for producing biogas}

The present invention relates to a biogas production facility which is capable of recycling raw materials and having high production efficiency.

One alternative energy to solve the problem of resource depletion is biogas. Biogas is a fuel produced by using discarded resources such as food waste and livestock manure, and the facility for producing biogas is considered as a method for preventing environmental pollution along with a function as a means of producing alternative energy.

Biogas is anaerobic, using biomass such as corn stalks, grains, waste feeds, waste fruits, livestock manure, algae, and organic wastes such as food waste, waste oils (glycerol), food waste, and sludge as raw materials. Produced by performing a digestion process to generate methane gas. The methane gas thus produced is used as energy in a manner of supplying electricity and heat by supplying the fuel of a generator (engine) or by supplying the fuel at high pressure by increasing the purity of methane gas.

1 is a view showing an example of a conventional biogas production apparatus, it is a view showing a biogas production apparatus disclosed in Korean Patent No. 0841089.

The biogas production apparatus of FIG. 1 performs an anaerobic digestion process on input raw materials, an anaerobic reactor 6 for generating biogas, and a buffer tank temporarily storing the digestion liquid discharged from the anaerobic reactor 6. (Membrane Separation System) 8 for discharging the digestion liquid in the buffer tank 7 and the buffer tank 7 into a filtrate and a concentrate. The concentrate discharged from the membrane device (8) is returned to the anaerobic reactor (6) through the return pipe (9), whereby the concentrate is reused as a raw material and also to ensure a sufficient amount of anaerobic microorganisms in the anaerobic reactor (6) Can be.

However, the conventional biogas production apparatus as described above has the following problems.

First, in the conventional biogas production apparatus, the concentration ratio of the membrane device 8 is low to produce a large amount of concentrate, and when a large amount of the concentrate is returned to the anaerobic reactor 6 through the return pipe 9, the stay The shortening of the retention time does not ensure sufficient time to decompose anaerobic microorganisms, thereby reducing digestion efficiency.

Secondly, in the conventional biogas production apparatus, as long-term use, debris (pollutants) accumulate in the anaerobic reactor 6, the effective volume of the anaerobic reactor 6 is reduced, and as a result, the raw material is anaerobic reactor 6 The residence time in the inside becomes short, and the extinguishing efficiency in the anaerobic reactor 6 is lowered.

Third, the extinguishing liquid discharged from the anaerobic reactor 6 includes a large amount of solids and contaminants. In the conventional biogas production apparatus, the extinguishing liquid is directly filtered using the membrane device 8. Accordingly, there is a problem in that the filtration performance is deteriorated due to the overload of the membrane device 8, and thus the water quality of the treated water flowing out of the membrane device 8 is deteriorated.

Fourth, the conventional biogas production apparatus described above returns the concentrated liquid flowing out from the membrane device (8) to the anaerobic reactor (6), thereby producing biogas through the reuse of raw materials and maintaining the concentration of microorganisms in the anaerobic reactor (6) Although there is an advantage in that the efficiency can be increased, there are disadvantages in that the efficient use of resources and prevention of environmental pollution are insufficient because various ways of using the wastes discharged from the biogas production process are not proposed.

The present invention has been made to solve the above problems, an object of the present invention, by maximizing the concentration rate of the membrane device to minimize the flow rate to the anaerobic reactor to improve the residence time, to accumulate residue in the anaerobic reactor Effectively prevents the increase of the digestive efficiency of the anaerobic reactor, and prevents the overload of the membrane device for filtering the digestive fluid of the anaerobic reactor, biogas production apparatus that can increase the filtration performance and biogas production efficiency and improve the water quality of the treated water To provide.

Another object of the present invention, by presenting a method that can be utilized for a variety of applications through the additional treatment for the waste discharged from the biogas production process, biogas production apparatus that can bring efficient use of resources and prevention of environmental pollution To provide.

Biogas production apparatus according to the present invention for achieving the above object, an anaerobic digestion tank for producing biogas by performing an anaerobic digestion process for the raw material to be injected; A contaminant / solid remover for removing contaminants and solids in the digestive waste liquid discharged from the anaerobic digester; First conveying means for conveying the contaminants and solids discharged from the contaminant / solid remover to the anaerobic digester; A first filter for filtering the treated water discharged from the contaminant / solid remover; And a second conveying means for conveying the concentrated liquid discharged from the first filter to the anaerobic digestion tank.

The contaminants and solids exiting the contaminant / solid remover are dried by a dryer. In this case, the drier dries the contaminants and solids using combustion waste heat generated in the process of burning and generating biogas produced in the anaerobic digester.

The first filter is preferably composed of a microfiltration membrane or an ultrafiltration membrane filter.

The treated water discharged from the first filter is re-filtered by the second filter. The second filter is preferably composed of a reverse osmosis membrane filter.

A cooler is arranged between the first filter and the second filter. The cooler cools the treated water discharged from the first filter and then flows it into the second filter.

A plurality of anaerobic digesters are provided, and each of the anaerobic digesters is communicated with each other by a first connecting pipe so that the raw materials therein are shared by the anaerobic digesters. The first connecting pipe is opened and closed by a first valve. In addition, the storage space for storing the biogas in each anaerobic digester is communicated with each other by a second connecting pipe. The second connecting pipe is opened and closed by a second valve.

According to the present invention, since the contaminants and solids in the digestive waste fluid flowing into the first filter are substantially removed in advance by the contaminant / solid remover, the water quality of the treated water discharged from the first filter without deterioration of the performance of the first filter is generated. This is improved. In addition, since part of the dehydrated cake flowing out of the contaminants / solids remover is reused as a raw material of the anaerobic digester, efficient use of resources is possible, and since the remaining part of the dehydrated cake is discharged to the cake dryer, harmful and insoluble substances accumulate in the anaerobic digester. It is possible to prevent the degradation of the fire extinguishing efficiency and to ensure the stability of the installation.

In addition, it is possible to prevent damage to the reverse osmosis membrane filter and deterioration of water quality by the cooler provided between the first filter and the second filter. In addition, by storing the concentrated liquid discharged from the second filter in the storage tank, the concentrated liquid can be recycled later as a liquid fertilizer.

In addition, by distributing the raw materials evenly distributed in each anaerobic digester, it is possible to optimize the anaerobic digestion process for biogas production, and maximize the biogas production efficiency by maintaining the same biogas pressure in all storage spaces.

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

2 to 4 is a view showing a biogas production facility according to a preferred embodiment of the present invention.

First, referring to FIG. 2, the biogas production facility according to the present invention includes an anaerobic digestion tank 10, a storage tank 20, a contaminant / solid remover 30, a first treatment tank 40, and a first filter 50. , A second treatment water tank 60, a cooler 70, a second filter 70, a storage tank 90, a cake dryer 100, a first conveying pipe 110, and a second conveying pipe 120. It is configured by.

The anaerobic digester 10 performs a anaerobic digestion process on the input raw materials to generate biogas. The biogas produced is methane and hydrogen, and methane is mainly used as biogas. As raw materials, biomass such as corn stalks, waste grains, waste feeds, waste fruits, livestock manure and algae, and organic wastes such as food waste, glycerol (waste oil) and food waste are used. In the anaerobic digester 10, a large amount of microorganisms carrying out an anaerobic digestion process for such raw materials is contained. The anaerobic digester 10 has a storage space 11 for storing the biogas produced as a result of anaerobic digestion, and the biogas stored in the storage space 11 is required by a transfer means such as a blower 13. Transferred to place. The anaerobic digester 10 discharges digestive waste liquid as a result of performing anaerobic digestion of raw materials.

The reservoir 20 is disposed between the anaerobic digester 10 and the contaminant / solid remover 30. The storage tank 20 functions to temporarily store the digestion waste liquid discharged from the anaerobic digestion tank 10 before being introduced into the contaminant / solid remover 30.

The contaminant / solid remover 30 receives digestion waste liquid discharged from the anaerobic digestion tank 10 from the storage tank 20 and filters and removes contaminants and solids in the digestion waste liquid by performing a dehydration process on the digestion waste liquid. That is, the contaminants / solids remover 30 functions to remove raw waste (cold matter) and coarse solids discharged from the anaerobic digester 10. As the contaminant / solid remover 30, a contaminant remover, a centrifuge, a screw press, a filter press or a belt press may be employed.

A portion of the dewatered cakes (cold matter and solids) separated by the contaminant / solids remover 30 is transferred to the cake dryer 100 and the other part is returned to the anaerobic digester 10 through the first conveying pipe 110. In addition, the treated water discharged from the contaminant / solid remover 30 is stored in the first treated water tank 40.

The cake dryer 100 functions to dry the dewatered cake discharged from the contaminant / solid remover 30. The dehydrated cake dried in the cake dryer 100 is used as a solid fuel of a heat recovery facility (incineration facility). As a result, the dried dehydrated cake is recycled as a heat generating raw material for power generation or the like.

In order to dry the dehydrated cake, the cake dryer 100 needs heat supply, and the cake dryer 100 of the present invention burns waste heat generated by burning biogas produced in the anaerobic digester 10 to generate electricity. Is used as the heat source for drying the dehydrated cake. That is, the biogas produced in the anaerobic digester 10 is transferred to the power plant by the blower 13, the power plant to burn the biogas to produce electricity and heat (hot water). At this time, the combustion waste heat discharged after power generation from the power generation facility is supplied to the cake dryer 100 and used as the drying heat of the cake dryer 100. Accordingly, the combustion waste heat is recycled. For this treatment, a separate means such as a waste heat supply pipe (not shown) for supplying the combustion waste heat discharged from the power generation facility to the cake dryer 100 should be provided.

The first treatment water tank 40 is disposed between the contaminant / solid remover 30 and the first filter 50. The first treatment tank 40 functions to temporarily store the treated water discharged from the contaminant / solid remover 30 before entering the first filter 50.

The first filter 50 receives the treated water discharged from the contaminant / solid remover 30 from the first treated water tank 40 and filters the treated water. As the first filter 50, a membrane device such as micro filtration (MF) and ultra filtration (UF) may be employed. It is preferable that the first filter 50 is operated in a batch to maximize the concentration rate to 400% or more. The concentrated liquid concentrated by the first filter 50 is returned to the anaerobic digestion tank 10 through the second conveying pipe 120, and the treated water discharged from the first filter 50 is transferred to the second treatment tank 60. Stored.

Anaerobic microorganisms that produce biogas have physiological properties that are very slow to grow. When the digestive waste liquid of the anaerobic digester 10 containing anaerobic microorganisms is discharged to the outside as it is, the amount of microorganisms in the anaerobic digester 10 is gradually reduced, resulting in a fundamental problem in that biogas is not produced. Therefore, this problem is solved by returning the minimum amount of the high concentration liquid discharged from the first filter 50 to the anaerobic digester 10 through the second conveying pipe 120.

The second treatment tank 60 is disposed between the first filter 50 and the second filter 80 to temporarily store the treated water discharged from the first filter 50 before flowing into the second filter 80. Function

The second filter 80 receives the treated water discharged from the first filter 50 through the second treated water tank 60 and re-filters the treated water. The second filter 80 takes charge of the final treatment to discharge or reuse the treated water discharged from the first filter 50. The second filter 80 is preferably composed of a reverse osmosis membrane filter that requires less land and requires less operating costs. The storage tank 90 is installed at the rear end of the second filter 80 to store the concentrated liquid discharged from the second filter 80 for use as a concentrated liquid ratio.

On the other hand, a cooler 70 is provided between the second treatment water tank 60 and the second filter 80. The cooler 70 functions to receive the treated water discharged from the first filter 50 from the second treated water tank 60, cool it, and then flow it into the second filter 80. The cooler 70 may be disposed at the front end of the second treatment tank 60 or at the rear end as shown in FIG. 2. However, while the second treatment tank 60 stores the treated water of the first filter 50, the natural cooling is also performed to some extent in the second treatment tank 60, so as to increase the operating efficiency of the cooler 70. The cooler 70 is preferably disposed at the rear end of the second treatment water tank 60.

As described above, the first conveying pipe 110 conveys a part of the dewatering cake flowing out of the contaminant / solid remover 30 to the anaerobic digester 10. In order to facilitate such conveying, it is preferable to install a separate conveying device such as a pump (not shown) for forced conveyance of the dewatering cake in the first conveying pipe 110.

In addition, as described above, the second conveying pipe 120 conveys the solids and microorganisms discharged from the first filter 50 to the anaerobic digester 10. In the second conveying pipe 120, it is preferable to further install a separate conveying device such as a pump (not shown) for forced conveying. The concentrated liquid returned contains solids and microorganisms, which are used as raw materials for the anaerobic digester 10 and the microorganisms serve to maintain the concentration of microorganisms in the anaerobic digester 10.

3 and 4 are views illustrating a state in which a plurality of anaerobic digesters are installed in FIG. 2. Although only one anaerobic digester 10 is shown in FIG. 2, the anaerobic digester 10 is typically configured to increase the biogas production capacity by installing multiple dogs (four in FIGS. 3 and 4).

At this time, as shown in Figure 3 and 4, each of the anaerobic digester 10, the lower portion is communicated with each other by four first connecting pipes 15 so that the raw materials therein each anaerobic digester (10) It is configured to be shared by. Each of the first connecting pipes 15 is provided with a first valve 16, and each of the first connecting pipes 15 is provided with a pump 14. Therefore, the raw materials in the anaerobic digester 10 can be transported between the anaerobic digesters 10 through the first connecting pipe 15 according to the open / closed state of the first valve 16, at which time the pumping operation of the pump 14 Accordingly, the active movement of the raw material is possible.

In addition, as shown in FIG. 4, each anaerobic digester 10 has a storage space 11 at an upper portion thereof communicated with each other by a second connecting pipe 17 so that the biogas therein is in the anaerobic digester 10. It is configured to be shared by the storage spaces 11. Each second connecting pipe 17 is provided with a second valve 18.

According to the present invention as described above has the following advantages over the conventional biogas production apparatus shown in FIG.

-The impurities / solids remover 30 performs the removal of the impurities / solids on the digestive waste liquid discharged from the anaerobic digester 10 and then flows into the first filter 50. Therefore, since the contaminants and solids in the digestive waste fluid flowing into the first filter 50 are substantially removed in advance, the water quality of the treated water discharged from the first filter 50 without deteriorating the performance of the first filter 50. This is improved.

-When an appropriate amount of anaerobic microorganisms and solids that the contaminants / solids remover 30 cannot remove are introduced into the first treatment tank 40 and then supplied to the first filter 50, the best filtration performance is exhibited. Therefore, the first filter 50 can maintain a high concentration rate by securing as much as possible the microorganisms and solids supplied, and by returning a small amount of the concentrate to the anaerobic digester to ensure a long residence time and increase the efficiency of biogas production do.

Part of the dewatering cake flowing out of the contaminants / solids remover 30 is reused as a raw material of the anaerobic digester 10, thereby enabling efficient use of resources.

-The remaining part of the dewatered cake flowing out of the contaminants / solids remover 30 is discharged to the cake dryer 100 side. Compared with the conventional biogas production equipment shown in FIG. 1, in the conventional biogas production apparatus, the solids filtered in the membrane device 8 are all introduced into the anaerobic reactor 6, and thus, the insoluble material ( Residue) may accumulate to reduce the extinguishing efficiency of the anaerobic reactor 6, but in the present invention, since some of the contaminants and the coarse solids are periodically discharged to the cake dryer 100, harmful and insoluble substances are anaerobic digestion tank 10. It is prevented from accumulating in the prevention of degradation of the extinguishing efficiency and it is possible to ensure the stability of the installation.

-The dehydrated cake discharged to the cake dryer 100 is processed into a solid fuel by the cake dryer 100, and in the power generation process using the biogas produced in the anaerobic digester 10 as dry heat of the cake dryer 100. Combustion waste heat is used. Therefore, it becomes possible to recycle the discarded resources to energy production.

-The storage tank 20, the first treatment tank 40, and the second treatment tank 60 are installed at the rear end of the anaerobic digester 10, the contaminant / solid remover 30, and the first filter 50, respectively. Therefore, buffering for temporarily storing the extinguishing waste liquid and the treated water discharged is enabled, and it is possible to variably operate each component in the facility as necessary.

-A cooler is installed between the first filter 50 and the second filter 80. In the case of constituting the first filter 50 with the vortex generating type concentrator, the first filter 50 generates a lot of heat during operation, and the heat of the treated water reaches 60 ° C or higher. When the high temperature treated water flows into the reverse osmosis membrane filter, physical deformation of the membrane (increase in pore size) or damage of the membrane module (detachment of the adhesive part) may occur, which may cause performance degradation and water quality deterioration. The cooler 70 serves to prevent such a phenomenon by lowering the temperature of the treated water of the first filter 50.

The second filter 80 performs re-filtering on the treated water treated in the first filter 50. Re-filtration improves the quality of the treated water, so that it can be discharged with a significant reduction in the risk of environmental pollution, or the quality treated water can be reused. In addition, by storing the concentrated liquid discharged from the second filter 80 in the storage tank 90, the concentrated liquid can be recycled later as a liquid fertilizer.

-The material accommodating space in the anaerobic digester 10 is communicated by the first connecting pipe 15, and it is possible to control the communication using the first valve 16, and also to actively feed the material using the pump 14 This is possible. Therefore, the raw material is distributed and supplied evenly in each anaerobic digester 10 to optimize the anaerobic digestion process for biogas production, and further, when the anaerobic digester 10 is stopped, the anaerobic digester is stopped. By blocking the transfer of raw materials to (10), the operation of the equipment can be optimized and efficient.

Since the storage space 11 in the anaerobic digester 10 is communicated by the second connecting pipe 17, the pressure of the biogas in each storage space 11 is kept uniform. When the biogas pressure in the storage space 11 of any one anaerobic digester 10 is excessively lowered, the production efficiency of biogas may be lowered in the anaerobic digester 10, but in the present invention, all storage spaces 11 By maintaining the same biogas pressure within the), the biogas production efficiency can be maximized. In addition, when the operation of some anaerobic digester 10 is stopped, the storage space 11 may be separated through the second valve 18 for the anaerobic digester 10.

While the above has been shown and described with respect to preferred embodiments and applications of the present invention, the present invention is not limited to the specific embodiments and applications described above, the invention without departing from the gist of the invention claimed in the claims Various modifications can be made by those skilled in the art, and these modifications should not be individually understood from the technical spirit or the prospect of the present invention.

1 is a view showing an example of a conventional biogas production facility.

2 shows a preferred embodiment of a biogas production plant according to the invention.

3 and 4 are views showing a state in which a plurality of anaerobic digester is installed in FIG.

Claims (10)

delete delete delete delete delete Anaerobic digestion tank to produce a biogas by performing an anaerobic digestion process for the input raw material; A contaminant / solid remover for removing contaminants and solids in the digestive waste liquid discharged from the anaerobic digester; First conveying means for conveying the contaminants and solids discharged from the contaminant / solid remover to the anaerobic digester; A first filter for filtering the treated water discharged from the contaminant / solid remover; Second conveying means for conveying the concentrated liquid discharged from said first filter to said anaerobic digestion tank; A second filter configured to re-filter the treated water discharged from the first filter and constitute a reverse osmosis membrane filter; And And a cooler disposed between the first filter and the second filter to cool down the treated water discharged from the first filter and to introduce the second filter into the second filter. Anaerobic digestion tank to produce a biogas by performing an anaerobic digestion process for the input raw material; A contaminant / solid remover for removing contaminants and solids in the digestive waste liquid discharged from the anaerobic digester; First conveying means for conveying the contaminants and solids discharged from the contaminant / solid remover to the anaerobic digester; A first filter for filtering the treated water discharged from the contaminant / solid remover; And And a second conveying means for conveying the concentrated liquid discharged from the first filter to the anaerobic digester. The anaerobic digester is provided with a plurality, Wherein each of the anaerobic digesters is communicated with each other by a first connecting tube such that the raw materials therein are shared by the anaerobic digesters. The method of claim 7, wherein And a first valve for opening and closing the first connection pipe. Anaerobic digestion tank to produce a biogas by performing an anaerobic digestion process for the input raw material; A contaminant / solid remover for removing contaminants and solids in the digestive waste liquid discharged from the anaerobic digester; First conveying means for conveying the contaminants and solids discharged from the contaminant / solid remover to the anaerobic digester; A first filter for filtering the treated water discharged from the contaminant / solid remover; And And a second conveying means for conveying the concentrated liquid discharged from the first filter to the anaerobic digester. The anaerobic digester is provided with a plurality, And a storage space for storing the biogas in each anaerobic digester is communicated with each other by a second connecting pipe. The method of claim 9, And a second valve for opening and closing the second connection pipe.

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