KR20090116603A - System for bio gas purification and energy recovery - Google Patents

Abstract

PURPOSE: An apparatus for energy recovery and bio gas purification is provided to refine exhaust gas by combusting refined biogas, and to refine the bio gas by removing carbon dioxide components of the biogas. CONSTITUTION: An apparatus for energy recovery and bio gas purification includes a biogas generation part(110), a biogas transfer tube(120), a refining tank(130), a biogas reservoir(160), a furnace(200), an exhaust gas discharge pipe(210), a removal reaction tank(220), a sludge reservoir(150), and a decomposition tank(280). The apparatus for energy recovery and bio gas purification further includes a quicklime reservoir(300), a carbon dioxide accumulator tank(330) and a waste tank(170). The biogas generation part generates biogas by fermenting organic waste. The refining tank increases the content of methane gas contained in the biogas.

Description

Biogas Refining and Energy Recovery Unit {SYSTEM FOR BIO GAS PURIFICATION AND ENERGY RECOVERY}

The present invention relates to a biogas purification and energy recovery apparatus, and more particularly, it is possible to completely remove the carbon dioxide component contained in the biogas produced by fermentation of organic waste to produce high quality biogas consisting of methane gas. In addition, the present invention relates to a biogas energy recovery apparatus capable of completely removing carbon, such as carbon dioxide, contained in exhaust gases generated during combustion in order to convert biogas into energy, thereby preventing air pollution.

In general, one of the most anticipated biofuels as a substitute for fossil fuels is biogas, which is expected to be fully commercialized in the near future along with natural gas.

Biogas is obtained automatically by fermenting organic wastes with high biomass content, such as livestock manure, food waste, and sludge from sewage treatment plants. It is sufficient because it is constantly generated through activities.

In detail, biogas is produced by anaerobic digestion of organic wastes containing a large amount of organic materials under an aerobic condition in which oxygen does not exist, and is mainly formed of methane (CH ₄ : about 60 ~). 70%) and carbon dioxide (CO _2: consists of about 30-40%).

Here, anaerobic digestion treatment uses an anaerobic filter method in which a carrier is installed in an anaerobic digester using adhesive properties of anaerobic microorganisms, and granulation due to self immobilization of microorganisms. UASB (Upflow Anaerobolic Sludge Blanket) method is commonly used.

Biogas contains about 60 to 70% of methane, so it is usually burned to obtain electrical and thermal energy.

However, since the carbon dioxide contained in a large amount of about 30 to 40% during the combustion interferes with the oxidation action, there is a problem in that the calorific value due to combustion is low, and thus the conversion rate to electricity and thermal energy is low.

Therefore, many efforts have been made to solve this problem.

An example of this is the "Daewoo Two Phase Anaerobolic Bio-Gas System (commonly referred to as" DBS ")" developed by Daewoo E & C of the Republic of Korea. By separating carbon dioxide slightly and venting it into the air, the content of methane gas is increased to 75 ~ 80% and the carbon dioxide content is lowered to about 20%.

However, this method has a problem in that it cannot remove further carbon dioxide.

Therefore, at this point in time, there is a need for a technology that can more fully reduce the amount of carbon dioxide contained in biogas to maximize the purity of methane gas.

On the other hand, when biogas is combusted in a combustion furnace to convert it into other energy such as electricity, methane gas contained in the biogas reacts with oxygen, and a large amount of carbon dioxide is generated by the following mechanism to exhaust the exhaust gas. It is contained in.

"CH ₄ + 2O ₂ → 2H ₂ O ↑ + CO ₂ ↑ "

In this regard, carbon dioxide accounts for about 60% of all greenhouse gases and is a major culprit of global warming, with efforts to reduce emissions through early international agreements on climate change.

Therefore, in the generation of energy by burning biogas, it is necessary to actively reduce the carbon dioxide generated in the exhaust gas, but there are still no significant reduction technologies developed to satisfy efficiency, economic feasibility, and field applicability. .

The present invention was devised to solve the above problems, and by completely eliminating the carbon dioxide component contained in the biogas produced by fermenting organic waste, the purity of the contained methane gas can be increased as much as possible, the combustion An object of the present invention is to provide a biogas purification apparatus capable of producing high quality biogas having excellent energy conversion rate.

In addition, another object of the present invention, the biogas energy recovery apparatus that can effectively remove the carbon, such as carbon dioxide contained in the exhaust gas generated during combustion in order to convert the biogas into energy to prevent air pollution To provide.

Further, another object of the present invention is to remove and purify the carbon dioxide component in the biogas generated from the organic waste, and also to remove the carbon dioxide in the exhaust gas generated during the production of energy by burning the purified biogas. It is to provide a biogas purification and energy recovery apparatus that can be purified by.

The above objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention by those skilled in the art.

Biogas purification apparatus of the present invention for achieving the above object, the biogas generating unit for producing a biogas by fermenting organic waste; A biogas transport pipe for transporting the biogas generated and supplied by the biogas generator; A purification tank configured to increase the content of methane gas contained by contacting and removing carbon dioxide contained in the biogas, which is provided in the middle of the biogas delivery pipe, with the strong alkaline water contained therein; And a biogas storage tank configured to internally store the purified biogas that has passed through the purification tank. It includes.

Preferably, the sludge storage tank for receiving and storing the sludge produced by the removal reaction in the purification tank; It may further include.

Also preferably, the strong alkaline water is a calcium hydroxide component produced by the contact reaction between quicklime and water, and the sludge may be a calcium carbonate component produced by the contact reaction between the calcium hydroxide and the carbon dioxide.

Also preferably, the waste water immersion tank receiving the slag or coal ash waste and contacting with the received water to produce the strong alkaline water of the calcium hydroxide component to supply to the refining tank; It may further include.

On the other hand, the biogas energy recovery apparatus of the present invention for achieving the above object, the biogas storage tank for storing the biogas; A combustion furnace generating high heat by burning the biogas supplied from the biogas storage tank; An exhaust gas discharge pipe configured to transfer and discharge exhaust gas generated by combustion in the combustion furnace; And a removal reaction tank provided in the middle of the exhaust gas discharge pipe to remove carbon such as carbon dioxide contained in the exhaust gas by contacting strong alkaline water of the calcium hydroxide component contained therein. It includes.

Preferably, the waste water immersion tank receiving the slag or coal ash waste in contact with the received water to produce the strong alkaline water of the calcium hydroxide component to supply to the removal reaction tank; It may further include.

Also preferably, the sludge storage tank for receiving and storing the calcium carbonate sludge produced by the removal reaction in the removal reaction tank; And a decomposition tank for producing quicklime, which is a raw material necessary to generate the strong alkaline water of the calcium hydroxide component by decomposing the calcium carbonate supplied from the sludge storage tank using the high heat generated in the combustion furnace. It may further include.

Also preferably, the quicklime storage tank for receiving and storing the quicklime from the decomposition tank to supply to the removal reaction tank or the waste water immersion tank; And a carbon dioxide collection tank configured to receive and store carbon dioxide generated according to the decomposition reaction in the decomposition tank. It may further include.

Also preferably, the combustion furnace may be included in any one of a boiler, an internal combustion engine, an external combustion engine, a steam engine, an engine, a cogeneration plant, and a heat exchanger.

On the other hand, the biogas purification and energy recovery apparatus of the present invention for achieving the above object, the biogas generating unit for producing a biogas by fermenting the organic waste; A biogas transport pipe for transporting the biogas generated and supplied by the biogas generator; A purification tank configured to increase the content of methane gas contained by contacting and removing carbon dioxide contained in the biogas, which is provided in the middle of the biogas delivery pipe, with the strong alkaline water contained therein; A biogas storage tank configured to internally store the purified biogas through the purification tank; A combustion furnace generating high heat by burning the purified biogas supplied from the biogas storage tank; An exhaust gas discharge pipe configured to transfer and discharge exhaust gas generated by combustion in the combustion furnace; And a removal reaction tank provided in the middle of the exhaust gas discharge pipe to remove carbon such as carbon dioxide contained in the exhaust gas by contacting with strong alkaline water contained therein. It includes.

Preferably, the strong alkaline water may be a calcium hydroxide component.

Also preferably, the sludge storage tank for receiving and storing the calcium carbonate sludge produced by the removal reaction in the purification tank and the removal reaction tank; A decomposition tank for producing quicklime by decomposing the calcium carbonate supplied from the sludge storage tank using high heat generated in the combustion furnace; A quicklime storage tank receiving and storing the quicklime from the decomposition tank and then supplying the quicklime to the purification tank / removal reaction tank or the waste water immersion tank; And a carbon dioxide collection tank configured to receive and store carbon dioxide generated according to the decomposition reaction in the decomposition tank. It may further include.

According to the present invention, carbon dioxide contained in the biogas produced by fermentation of organic waste can be more completely removed to increase the purity of methane gas contained therein, thereby producing high quality biogas with excellent energy conversion rate during combustion. The effect can be achieved.

In addition, according to the present invention, in order to convert biogas into energy, carbons such as carbon dioxide contained in the exhaust gas generated at the time of combustion can be efficiently removed, thereby preventing air pollution by carbon dioxide, and gradually The effects of actively coping with the tightening regulations on CO2 emissions can be achieved.

In addition, according to the present invention, since it uses slag and coal ash generated in a large amount as waste in an industrial site, it is very economical, has excellent field applicability, and does not cause any other environmental pollution in the process of treatment, so it is eco-friendly. Can be achieved.

Furthermore, according to the present invention, since the quicklime, which is a starting raw material, is recycled and used, the raw material can be used as much as possible, and only a small amount of raw material can be consumed. Can be achieved.

Furthermore, according to the present invention, since calcium carbonate, high purity carbon dioxide, and quicklime, which can be usefully recycled, are also provided as by-products, excellent effects of economic efficiency and utility can be achieved in this regard.

In addition, since the waste of slag and coal ash can be harmlessly treated, an effect of preventing environmental pollution generated at the time of simple landfill of the wastes can be achieved.

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

1 is a block diagram showing a biogas purification apparatus according to the present invention.

Biogas purification apparatus according to the present invention, the biogas generation unit 110 for fermenting organic waste to generate biogas, and the biogas delivery pipe for transporting the biogas generated and supplied by the biogas generator 110 The carbon dioxide contained in the biogas passing through the biogas delivery pipe 120 and the strong alkali water of the calcium hydroxide (Ca (OH) ₂ ) component is contacted and removed to increase the content of methane gas. Sludge for receiving and storing the purification tank 130, the biogas storage tank 160 for storing the purified biogas inside, and the calcium carbonate (CaCO ₃ ) sludge produced by the removal reaction in the purification tank 130 Reservoir 150.

The biogas generating unit 110 ferments various organic wastes such as livestock manure, food waste, and sewage treatment plant sludge to generate biogas mainly composed of methane gas and carbon dioxide.

The biogas generating unit 110 is not particularly limited in the specific treatment method or configuration, that is, may be used any treatment method or configuration that is currently being applied or can be developed and applied later.

As an example, the biogas generating unit 110 receives an organic waste that has been appropriately pretreated by solid-liquid separation and the like and fermentation and decomposition to generate biogas, and various traces of harmful substances contained in biogas generated in the digester. It may be configured to include a post-processing unit for removing the.

The purification tank 130 passes through the biogas provided in the middle of the biogas delivery pipe 120, and removes carbon dioxide contained in the biogas using strong alkaline water of the calcium hydroxide component contained therein.

That is, the carbon dioxide contained in the biogas is removed by passing biogas through the strong alkali water of the internally contained calcium hydroxide component, and the removal reaction at that time is "Ca (OH) ₂ + CO ₂ → CaCO ₃ + H ₂ O. "to be.

The purification tank 130 may directly generate quick alkali (CaO) and water from the outside to generate strong alkali water of calcium hydroxide components by reaction between them, and alternatively, as shown in FIG. 2, strong alkaline water from outside May be supplied.

When the purification tank 130 directly generates strong alkaline water, strong alkaline water having a calcium hydroxide component of pH 10 to 12 or more is produced according to the reaction formula of "CaO + H ₂ O → Ca (OH) ₂ ".

On the other hand, when the refining tank 130 is supplied with strong alkaline water from the outside, a separate waste water immersion tank 170 for generating strong alkaline water and supplying it to the refining tank 130 is further provided. 170 receives industrial waste such as slag or coal ash (that is, ash) and reacts with water contained therein to generate strong alkaline water of calcium hydroxide and supply it to the refining tank 130.

In this regard, in the steelmaking process of iron ore, limestone is added together to easily remove iron from iron ore, and thus, slag generated as a large amount of waste in the steelmaking process includes unreacted quicklime. Reaction with water produces calcium hydroxide, which exhibits a strong alkalinity of pH 10-12 or higher.

In addition, coal ash generated as a by-product of combustion in a coal-fired power plant that obtains thermal energy by burning coal is an inorganic substance remaining after combustion, and bottom ash accumulated directly by falling down to the bottom of the combustion furnace. It is divided into fly ash which is discharged through the flue of the upper part along with exhaust gas, and these bottom ash and fly ash basically contain about 2 ~ 45% of quicklime component. Reaction with water produces calcium hydroxide, which exhibits a strong alkalinity of pH 10-12 or higher.

The waste immersion tank 170 may be provided as one to generate strong alkaline water by inputting all of the slag and coal ash without distinguishing it, or alternatively, two may be provided to generate strong alkaline water by separately inputting slag and coal ash. .

The waste immersion tank 170 may be provided with an impact imparting means (not shown) for repeatedly extracting the slag and coal ash, which are added to the waste immersion tank, so that the contained quicklime component may be extracted more effectively and maximally.

The impact imparting means may be any one that can continuously apply the impact to the injected slag, coal ash, for example, may be implemented as a rotating cylinder that can repeatedly impact the received waste is rotated inside the waste water immersion tank 170.

The strong alkali water of the calcium hydroxide component generated in the waste water immersion tank 170 is supplied to the purification tank 130 through the strong alkaline water transport pipe 180, in which the transport drive such as a pump provided on the strong alkaline water transport pipe 180 The conveying force can be given by means (not shown).

Again, the purification tank 130 may be provided with a contact rate improving means (not shown) for improving the contact rate between the internally contained calcium hydroxide and the carbon dioxide contained in the inflowing biogas to make the removal reaction quick and efficient. The means for improving the contact rate may include rotating means for rotating the received strong alkali water, agitation means for stirring the strong alkaline water, gas fractionation means for subdividing and injecting the incoming biogas, and aeration for injecting the inflowing biogas. (Iii) means, or the like.

In removing the carbon dioxide contained in the biogas using the strong alkaline water in the refining tank 130, the strong alkaline water supplied from the waste water immersion tank 170 or the strong alkaline water in the refining tank 130 is further improved. To the biogas delivery pipe 120 in front of the refining tank 130, and supplied by the first biogas and strong alkali water in the biogas delivery pipe 120 in front of the first removal reaction, and then the purification tank At 130, the second removal reaction can be made in earnest.

To this end, a withdrawal pipe 135 for transporting and supplying the strong alkaline water supplied from the waste water immersion tank 170 or the strong alkaline water in the purification tank 130 to the biogas delivery pipe 120 in front of the purification tank 130 is provided. At the end of the outlet pipe 135, a spray nozzle (not shown) is provided for subdividing and spraying the strong alkaline water into the biogas delivery pipe 120, and a pump for transporting the strong alkaline water through the outlet pipe 135 is provided. Transfer driving means such as (not shown) may be provided.

In accordance with the removal reaction in the refining tank 130, calcium carbonate sludge is generated and deposited therein as a reaction by-product, and the deposited calcium carbonate sludge is transferred through the sludge transfer pipe 140 and stored in the sludge storage tank 150. In this case, the sludge conveying pipe 140 may be provided with a conveying means (not shown) such as a screw-type rotating body to convey the sludge.

The biogas storage tank 160 receives the purified biogas by removing the carbon dioxide contained therein while passing through the purification tank 130 and storing the internally.

The sludge storage tank 150 internally stores the calcium carbonate sludge which is generated and supplied as a reaction by-product according to the removal reaction in the purification tank 130, and the stored calcium carbonate is externally drawn out if necessary to be used for steel, cement and fertilizer. It can be recycled suitably as raw materials for manufacture.

On the other hand, Figure 3 is a block diagram showing a biogas energy recovery apparatus according to the present invention.

The biogas energy recovery apparatus according to the present invention produces energy by burning the purified biogas through the above-described biogas purification apparatus.

The configuration includes a biogas storage tank 160 for storing and supplying purified biogas internally, a combustion furnace 200 for generating high heat by burning the purified biogas supplied from the biogas storage tank 160, Exhaust gas discharge pipe 210 for transporting and discharging the exhaust gas generated by combustion in the combustion furnace 200, and carbon such as carbon dioxide contained in the exhaust gas passed in the middle of the exhaust gas discharge pipe 210 to pass through The removal reaction tank 220 which contacts and removes the strong alkali water of a calcium hydroxide component, the sludge storage tank 240 which receives and stores the calcium carbonate sludge produced by the removal reaction in the removal reaction tank 220, and the sludge storage tank 240 And a decomposition tank 280 for decomposing calcium carbonate supplied from the furnace using high heat generated in the combustion furnace 200 to generate quicklime as a raw material.

The purified biogas stored in the biogas storage tank 160 is transferred to the combustion furnace 200 through the purified biogas delivery pipe 190.

Combustion furnace 200 generates a high heat by burning the purified biogas, the resulting high heat is used to generate hot water, hot steam or other forms of energy, such as mechanical movement, electricity.

Therefore, the combustion furnace 200 may be specifically included in a boiler, an internal combustion engine, an external combustion engine, a steam engine, an engine, a cogeneration plant, a heat exchanger, and the like.

Combustion of the biogas, the main component of methane gas in the combustion furnace 200, generates a large amount of carbon dioxide according to the following reaction formula and is contained in the exhaust gas.

"CH ₄ + 2O ₂ → 2H ₂ O ↑ + CO ₂ ↑ "

The exhaust gas discharge pipe 210 internally transports and discharges exhaust gas generated by combustion in the combustion furnace 200.

The removal reaction tank 220 passes through the exhaust gas, which is provided in the middle of the exhaust gas discharge pipe 210, and passes through and removes carbon such as carbon dioxide contained in the exhaust gas by contacting strong alkaline water of the calcium hydroxide component contained therein.

That is, if contact with the exhaust gas to be strong alkali contained within the calcium component is removed is carbon dioxide contained in the exhaust gas, is removed then the scheme is _{"Ca (OH) 2 + CO} 2 → CaCO 3 + H 2 O".

The removal reaction tank 220 may directly receive quicklime and water to generate calcium hydroxide according to a reaction therebetween, or may receive strong alkaline water from a separate waste water immersion tank 250.

The waste immersion tank 250 receives slag and coal ash waste and reacts with the water contained therein to generate strong alkali water of calcium hydroxide component and supply it to the removal reaction tank 220, wherein the strong alkaline water is supplied through the strong alkaline water transfer pipe 260. Transferred.

In order to more efficiently remove the carbon dioxide contained in the exhaust gas, the strong alkaline water supplied from the waste water immersion tank 250 or the strong alkaline water in the removal reaction tank 220 is removed from the front of the removal reaction tank 220 through the extraction pipe 225. Supplying to the exhaust gas transport pipe 210, the first exhaust gas and strong alkali water in the exhaust gas transport pipe 210 in front of the first removal reaction is made, and then the second removal in earnest in the removal reaction tank 220 in earnest The reaction can be made.

Of course, the exhaust gas purified while passing through the removal reaction tank 220 may be discharged through the exhaust gas discharge pipe 210 behind the removal reaction tank 220 and finally discharged to the atmosphere.

The sludge storage tank 240 stores the calcium carbonate sludge which is generated according to the removal reaction in the removal reaction tank 220 and then transferred and supplied through the first sludge delivery pipe 230, and the stored calcium carbonate is externally drawn out as necessary. It can be recycled as raw materials for steel, cement and fertilizer production.

Then, the calcium carbonate stored in the sludge storage tank 240 is then transferred to the decomposition tank 280 through the second sludge transport pipe 270, and is supplied.

The decomposition tank 280 decomposes the calcium carbonate supplied from the sludge storage tank 240 using high heat transferred from the combustion furnace 200 by the following reaction formula to generate quicklime and carbon dioxide as raw materials.

"CaCO ₃ (heat above 860 ℃) → CaO + CO ₂ ↑"

According to this reaction, calcium carbonate is decomposed into quicklime and carbon dioxide only when heated to 860 ℃ or more, the combustion furnace 200 according to the present invention does not interfere with the oxidation of carbon dioxide by burning the purified biogas at all Therefore, it is possible to generate a high heat of 860 ° C or more sufficiently.

Preferably, the decomposition tank 280 may be provided adjacent to the combustion furnace 200 to be able to smoothly receive high heat from the combustion furnace 200.

Furthermore, the biogas energy recovery apparatus of the present invention stores the quicklime that is generated and supplied according to the decomposition reaction in the decomposition tank 280 and then supplied to the removal reaction tank 220 to be used for the production of calcium hydroxide to generate calcium hydroxide. 300 and a carbon dioxide collection tank 330 that receives and stores high-purity carbon dioxide generated according to the decomposition reaction in the decomposition tank 280.

The quicklime component generated by the decomposition reaction in the decomposition tank 280 is transferred to and stored in the quicklime storage tank 300 through the first transfer pipe 290, and the carbon dioxide generated according to the decomposition reaction is transferred to the third transfer pipe 320. Is transferred to the carbon dioxide collection tank 330 and stored therein.

The quicklime storage tank 300 stores the quicklime that is generated and supplied according to the decomposition reaction in the decomposition tank 280, and the stored quicklime is then removed through the second transfer pipe 310 to the reaction tank 220 or the waste water immersion tank ( 250) and used to produce calcium hydroxide.

Of course, the quicklime stored in the quicklime storage tank 300 may be immediately taken out and recycled as an industrial or energy raw material.

The carbon dioxide collection tank 330 stores high-purity carbon dioxide that is generated and supplied according to the decomposition reaction in the decomposition tank 280, and may be compressed or cooled to store a larger amount during the storage. The collected carbon dioxide can then be recycled as plant cultivation or industrial raw materials to promote photosynthesis of plants.

In addition, the carbon dioxide stored in the carbon dioxide collection tank 330 may be transferred to the exhaust gas discharge pipe 210 in front of the removal reaction tank 220 and removed if necessary.

On the other hand, Figure 4 is a block diagram showing a biogas purification and energy recovery apparatus according to the present invention.

The biogas purification and energy recovery apparatus according to the present invention basically has a configuration in which the above-described biogas purification apparatus and the biogas energy recovery apparatus are merged.

The constitution includes a biogas generator 110 for fermenting organic waste to generate biogas, a biogas delivery pipe 120 for transferring biogas generated by the biogas generator 110, and biogas transfer. A purification tank 130 for increasing the content of methane gas contained therein by contacting and removing carbon dioxide contained in the biogas provided in the middle of the pipe 120 and the strong alkali water of the calcium hydroxide component, and storing the purified biogas internally. The biogas storage tank 160 to be supplied thereafter, the combustion furnace 200 that generates high heat by burning the purified biogas supplied from the biogas storage tank 160, and are discharged according to combustion in the combustion furnace 200. The exhaust gas discharge pipe 210 for transporting and discharging the exhaust gas to be discharged, and the carbon, such as carbon dioxide contained in the exhaust gas passed in the middle of the exhaust gas discharge pipe 210 to pass through Sludge storage tank 150 for receiving and storing the removal reaction tank 220 for contacting and removing the strong alkaline water of the calcium component, and the calcium carbonate sludge produced by the removal reaction in the purification tank 130 and the removal reaction tank 220. Decomposition of the calcium carbonate supplied from the sludge storage tank 150 using high heat generated in the combustion furnace 200 to produce quicklime which is a raw material to be supplied to the purification tank 130 and the removal reaction tank 220. And tank 280.

And, after receiving and storing the quicklime generated according to the decomposition reaction in the decomposition tank 280 and then in the quicklime storage tank 300 to supply to the purification tank 130 and the removal reaction tank 220, and in the decomposition tank 280 It may further include a carbon dioxide collection tank 330 for receiving and storing high-purity carbon dioxide generated according to the decomposition reaction of the.

* In addition, the slag and coal ash waste may be further reacted with the water contained therein to generate a strong alkaline water of the calcium hydroxide component, and may further include a waste water immersion tank 170 for supplying to the purification tank 130 and the removal reaction tank 220. have.

The purified biogas stored in the biogas storage tank 160 is transferred to the combustion furnace 200 through the purified biogas delivery pipe 190.

The waste water immersion tank 170 reacts slag and coal ash with water to generate strong alkaline water of calcium hydroxide, and supplies it to the purification tank 130 and the removal reaction tank 220 through the strong alkali water supply pipe 180.

In removing the carbon dioxide contained in the biogas and the exhaust gas using the strong alkaline water in the purification tank 130 and the removal reaction tank 220, the strong alkaline water is transferred to the biogas transfer pipe through the extraction pipes 135 and 225 ( 120 and the first exhaust reaction may be supplied into the exhaust gas transfer pipe 210.

The quicklime generated by the decomposition reaction in the decomposition tank 280 is transferred to the quicklime storage tank 300 through the first transfer pipe 290 and stored, the quicklime stored in the quicklime storage tank 300 is the second transfer pipe ( It is transported through 310 and supplied to the purification tank 130 and the removal reaction tank 220.

In addition, the carbon dioxide generated by the decomposition reaction in the decomposition tank 280 is transferred to the carbon dioxide collection tank 330 through the third transfer pipe 320 and stored.

In addition, the high heat generated in the combustion furnace 200 may be delivered to the digester in the biogas generator 110 to be used to warm the digester. When the digester is heated, the digestion action for the production of biogas is more rapid. It can be done efficiently.

In addition, the above-described biogas purification apparatus, biogas energy recovery apparatus, and biogas purification and energy recovery apparatus may further include a control panel (not shown) that performs overall operation control to enable automatic operation, and furthermore, each object On the transfer pipe or the supply pipe for transporting the opening and closing means (not shown) for controlling the supply amount by opening and closing the transfer of the object, a flow meter (not shown) and a hydraulic system for measuring the transfer flow rate and the transfer pressure of the object ( (Not shown), and a bath for generating and storing each object may be appropriately provided with a pH measurement means (not shown) for measuring hydrogen ion concentration.

In addition, in the above, as a raw material, the strong alkali water of the calcium hydroxide component is generated using the quicklime component and the carbon dioxide is removed using the strong alkali water of the calcium hydroxide component, but it is typical to remove carbon such as carbon dioxide. As the strong alkaline water, other sodium hydroxide and potassium hydroxide may be used.

As a result, according to the biogas purification and energy recovery apparatus according to the present invention, the carbon dioxide contained in the biogas may be more completely removed to increase the content of methane gas as much as possible, thereby producing high quality biogas.

In addition, according to the present invention, in order to convert the biogas into energy, it is possible to efficiently remove carbon such as carbon dioxide contained in the exhaust gas discharged at the time of burning the biogas, so that air pollution by the carbon dioxide (global ozone layer) Destruction, global warming, urban greenhouse effect, etc.), and can actively cope with the stricter regulations on CO2 emissions.

In addition, according to the present invention, since it uses slag and coal ash generated in a large amount as waste in an industrial site, it is very economical and has excellent field applicability, and also does not cause any other environmental pollution in the process of treatment, thus there is an environmentally friendly advantage. .

Furthermore, according to the present invention, since the raw lime is recycled and used, the raw material can be utilized as much as possible, and only a small amount of raw material can be used, thereby providing economical efficiency and utility. Calcium carbonate, high purity carbon dioxide and quicklime can also be provided as by-products, which can be easily recycled.

Further, since the waste of slag and coal ash can be harmlessly treated, it is also possible to prevent environmental pollution generated when the waste is simply landfilled.

In the foregoing description, it should be understood that those skilled in the art can make modifications and changes to the present invention without changing the gist of the present invention as merely illustrative of a preferred embodiment of the present invention.

1 is a block diagram showing a biogas purification apparatus according to an embodiment of the present invention,

2 is a block diagram showing a biogas purification apparatus according to another embodiment of the present invention,

3 is a block diagram showing a biogas energy recovery apparatus according to the present invention,

Figure 4 is a block diagram showing a biogas purification and energy recovery apparatus according to the present invention.

<Description of the symbols for the main parts of the drawings>

110: biogas generation unit 120: biogas delivery pipe

130: refining tank 135: withdrawal tube

140: sludge feed pipe 150: sludge storage tank

160: biogas storage tank 170: waste water immersion tank

180: strong alkaline water delivery pipe 190: purified biogas delivery pipe

200: combustion furnace 210: exhaust gas discharge pipe

220: removal reactor 225: withdrawal tube

230: first sludge feed pipe 240: sludge storage tank

250: waste water immersion tank 260: strong alkaline water transfer pipe

270: second sludge feed pipe 280: decomposition tank

290: first transfer pipe 300: quicklime storage tank

310: second transport pipe 320: carbon dioxide transport pipe

330: carbon dioxide collection tank

Claims (5)

A biogas storage tank for storing biogas inside; A combustion furnace generating high heat by burning the biogas supplied from the biogas storage tank; An exhaust gas discharge pipe configured to transfer and discharge exhaust gas generated by combustion in the combustion furnace; And And a removal reactor for removing carbon such as carbon dioxide contained in the exhaust gas passed in the middle of the exhaust gas discharge pipe by contacting strong alkaline water of a calcium hydroxide component contained therein. The method of claim 1, A biogas energy recovery apparatus further comprising a waste water immersion tank for inputting slag or coal ash waste and reacting with the received water to generate the strong alkaline water of the calcium hydroxide component and supply it to the removal reaction tank.  The method according to claim 1 or 2, A sludge storage tank for receiving and storing calcium carbonate sludge produced by the removal reaction in the removal reaction tank; And Biogas energy recovery apparatus further comprises a decomposition tank for generating the quicklime which is a raw material required to generate the strong alkali water of the calcium hydroxide component by decomposing the calcium carbonate supplied from the sludge storage tank using the high heat generated in the combustion furnace. . The method of claim 3, wherein A quicklime storage tank receiving and storing the quicklime from the decomposition tank and then supplying the quicklime to the removal reaction tank or the waste water immersion tank; And Biogas energy recovery apparatus further comprises a carbon dioxide collection tank for receiving and storing carbon dioxide generated by the decomposition reaction in the decomposition tank. The method according to claim 1 or 2, The combustion furnace is a biogas energy recovery apparatus, characterized in that included in any one of a boiler, an internal combustion engine, an external combustion engine, a steam engine, an engine, a cogeneration plant, a heat exchanger.

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