KR100296626B1 - Apparatus and method for landfill gas purification and leachate pretreatment - Google Patents

Abstract

The present invention relates to landfill gas purification and leachate pretreatment of waste, wherein the lime-containing waste administered to the leachate fixes a portion of carbon dioxide in the landfill gas to form a precipitated solid to remove colloidal, floating and some soluble substances in the leachate. The purpose of the present invention is to provide an apparatus and method for facilitating the energy resource of landfill gas by removing carbon dioxide from landfill gas and increasing methane content during the pretreatment of leachate, as well as by polycondensation and coprecipitation. have.

The present invention, quicklime storage tank (61); A gas-liquid reaction tank 63 receiving the landfill gas through one lower side thereof, and an exhaust hole formed at an upper end thereof; A contact medium 64 which fills the inner central portion of the gas-liquid reaction tank transversely in a transverse direction; Leachate injection means for supplying waste leachate and quicklime through the gas-liquid reaction tank 63; A heat exchanger (65) which receives the landfill gas from which carbon dioxide has been removed by reaction with the leachate in the gas-liquid reaction tank (63) through the exhaust hole (63a), and burns the methane component of the landfill gas to recover thermal energy. ); And, a sedimentation tank (68) for receiving the leachate from which the colloidal, floating and soluble substances precipitated from the gas-liquid reaction tank 63, sedimentation and sludge sedimentation; An apparatus comprising a and a method using the apparatus are provided.

Through such a configuration, when carbon dioxide in landfill gas and leachate containing lime powder waste (waste alkali) are reacted, calcium carbonate is formed, and solids can be separated by reacting with contaminants in leachate during the formation. The quality of the leachate can be greatly improved. In addition, by directly removing the carbon dioxide in the landfill on-site, the content ratio of the methane gas is also increased to increase the heat of the landfill gas, thereby making it easier to reuse the landfill gas.

Description

Apparatus and method for landfill gas purification and leachate pretreatment

The present invention is a method for pretreatment or simple treatment of leachate in a landfill by a mechanism for removing contaminant chambers in leachate using carbon dioxide and quicklime (including waste containing lime, hereinafter abbreviated as 'quick lime') in landfill gas. In this regard, the preliminary process is carried out by the quicklime administered to the leachate to fix the carbon dioxide in the landfill gas to form a precipitated solid, thereby removing colloidal, suspended and some soluble substances in the leachate by polycondensation and coprecipitation. And method for landfill gas purification and leachate pretreatment, which allows the landfill gas purification process to remove the carbon dioxide in the landfill gas to increase the methane content to facilitate the energy resource of the landfill gas. (The System and Method for Refining Reclamation Gas and Pre-processi ng the Deposit).

The leachate produced in the Seoul metropolitan landfill is discharged through the multi-step advanced treatment which is finally treated with RBC through anaerobic digestion tank, aeration lagoon tank and fenton oxidation, but the treatment efficiency is not very high compared to the cost used for treatment. In addition, leachate generally contains high concentrations of various inorganic and hardly decomposable substances such as heavy metals, adding complexity to the treatment.

On the other hand, when the landfill gas generated in the landfill is discharged into the atmosphere, the landfill gas is severely polluted to become a factor that destroys the environment. Therefore, in most of the landfills, as shown in Figure 1, by installing a landfill gas combustion facility to burn the landfill gas generated from the landfill in the combustion chamber (1) and then discharge it through the discharge pipe (2), Air pollution by landfill gas is being reduced.

In addition, in another form of the conventional landfill gas treatment facility, as shown in Figure 2, while the landfill gas first passes through the filter 11 and the desulfurization unit 12, the primary purification by condensation, filtration and adsorption, etc. After that, there is a landfill gas purification apparatus configured to burn in the boiler 13. That is, in the landfill gas purification apparatus, solid materials such as dust and sulfur compounds contained in the landfill gas are first filtered through the filter 11 and the desulfurization unit 12, and the landfill gas purified in this way is a boiler. It was burned in (13) and discharged to the atmosphere, and it was configured to recover and use the heat energy generated in the combustion process.

However, while the landfill gas generated in most landfills has a low methane content of 40 to 50%, while the content of carbon dioxide is high at 50 to 60%, the landfill gas is not sufficiently burned. In the gas treatment apparatus, even after a combustion process, a large amount of methane and carbon dioxide are discharged into the atmosphere as it is, thereby contaminating the atmosphere. In addition, the methane content in the landfill gas generated at each landfill varies greatly from 20% to 70% over time, and such a large variation in the methane content also becomes a significant obstacle to using landfill gas as an energy resource.

In addition, in the conventional landfill gas purification apparatus, solids such as dust and sulfur compounds may be removed to some extent, but dust and sulfur compounds collected in the filter and the desulfurizer should be collected separately and disposed of by a method such as landfill. There was a problem of environmental pollution.

Therefore, the present invention was made to solve the above problems, by washing the landfill gas generated in the landfill land with waste leachate mixed with quicklime, by sedimentation and removal of carbon dioxide in the landfill gas, An apparatus for refining landfill gas and pre-treatment of leachate which increases the methane content in landfill gas to facilitate the energy resource of landfill gas, and improves the combustion rate of landfill gas to prevent the discharge of pollutants into the atmosphere. The main purpose is to provide the method.

Another object of the present invention is to configure the waste landfill gas, so that the contaminants in the leachate is removed by sedimentation in the process of washing the waste leachate mixed with quicklime, the pretreatment process of the leachate can be carried out at the same time The present invention provides an apparatus and method for reclaiming landfill gas and pretreatment of leachate.

1 is an illustration of a conventional method for treating landfill gas

2 is an illustration of a conventional waste landfill gas purification process

3 is a block diagram of an apparatus according to an embodiment of the present invention,

4 is a block diagram of an apparatus according to another embodiment of the present invention,

5 is a flow of landfill gas purification and leachate pretreatment method according to the present invention

Degree.

6 is a graph showing the conversion of Ca ²⁺ (aq) over time.

7 is a graph showing the concentration of each component in the reactor

8 is a graph showing the change of reaction rate with time

* Explanation of symbols for main parts of the drawings

51, 61: quicklime storage tank 52: mixer

53 pump 54a injection nozzle

55, 63: gas-liquid reaction tank 56, 64: contact medium

57, 65: heat exchanger 58, 68: sedimentation tank

62: acid filter 66: auxiliary coagulant feeder

67 stirrer

The present invention for achieving the above object, the quicklime storage tank is stored quicklime; A gas-liquid reaction tank receiving the landfill gas through one lower side thereof and having an exhaust hole formed at an upper end thereof; A contact medium filling the inner central portion of the gas-liquid reaction vessel transversely and having a plurality of pores; Leachate injection means for supplying the leachate and quicklime through the gas-liquid reaction tank so that the landfill leachate and the quicklime is filled in the voids of the contact medium; A heat exchanger which receives the landfill gas from which carbon dioxide has been removed by reaction with the leachate mixed with the quicklime in the gas-liquid reaction tank through the exhaust hole, and recovers thermal energy by burning a methane component of the landfill gas; And, by reacting in the gas-liquid reaction tank, quicklime is sedimented and removed, and colloidal, floating and soluble materials are aggregated to inhale the leachate sedimented and removed in the contact medium, and the sludge contained in the leachate is sedimented and sorted. Sedimentation tank; Characterized in having a.

The present invention also provides a leachate supplying step of supplying landfill leachate and quicklime to the gas-liquid reaction tank by using the leachate injecting means so as to be filled in the pores of the contact media; A landfill gas supply step of supplying a landfill gas into the gas-liquid reaction tank through the lower frame of the gas-liquid reaction tank after the leachate supplying step; After the landfill gas supplying step, the landfill gas supplied to the gas-liquid reaction tank passes through the contact medium and reacts with leachate mixed with quicklime, and carbon dioxide in the landfill gas is solidified and separated, and the quicklime is calcined and alkali in water. A reaction step of sedimentation and separation by contact medium, and colloidal, floating and soluble materials of the leachate settle and separation by contact medium; And, after the reaction step, after receiving the landfill gas from which carbon dioxide is removed from the gas-liquid reaction tank to the heat exchanger, a combustion step of burning to generate heat energy; Characterized in that it comprises a.

Hereinafter, with reference to the accompanying drawings a preferred embodiment of the apparatus and method for the landfill gas purification and leachate pretreatment according to the present invention.

3 is a schematic diagram of a device for refining landfill gas and pre-treatment of leachate according to an embodiment of the present invention, as shown, a quicklime storage tank 51, a gas-liquid reaction tank 55, a contact filtrate 56, and a leachate It comprises an injection means, a heat exchanger 57 and a settling tank 58.

The gas-liquid reaction tank 55 is a cylinder installed on the ground, and an intake hole 55a through which the landfill gas is sucked is formed at one lower side thereof, and an exhaust hole 55b is formed at one side of the upper end thereof to discharge gas filled therein. It is configured to be. The contact filter 56 is a filtering member such as a sponge having a plurality of voids, and the buried gas sucked through the intake hole 55a of the gas-liquid reaction tank 55 passes through the contact filter 56. After being fixed through the exhaust hole 55b, the gas-liquid reaction tank 55 is fixed in such a manner as to be transversely filled in the inner central portion thereof.

The leachate injection means is configured to supply the leachate and quicklime to the gas-liquid reaction tank 55 so that the quicklime stored in the quicklime storage tank 51 and the landfill leachate are filled in the voids of the contact medium. This leachate injection means, as shown in Figure 3, may comprise a mixer 52, a pump 53 and a supply pipe 54.

The mixer 52 is configured to receive the leachate generated from the landfill and the quicklime, and to stir them sufficiently for a predetermined time to sufficiently mix them.

The supply pipe 54 extends from the mixer 52 and is installed to penetrate through an upper side of the gas-liquid reaction tank 55. A plurality of injections are provided at a portion of the supply pipe 54 extending into the gas-liquid reaction tank 55. The nozzle 54a is configured to be formed. In addition, the pump 53 is installed at one side of the supply pipe 54, and by feeding the leachate mixed with quicklime in the mixer 52 to the gas-liquid reaction tank 55, the upper portion of the gas-liquid reaction tank 55 is provided. Through the injection nozzle 54a of the supply pipe 54 installed, the leachate mixed with quicklime is injected, and thus, the leachate mixed with the quicklime is configured to be filled in the voids of the contact medium 56.

The heat exchanger (57) is composed of a boiler or the like configured to suck the landfill gas through the exhaust hole (55b) of the gas-liquid reaction tank (55) and to recover the heat energy generated during the combustion process. In this case, the landfill gas discharged through the exhaust hole (55b) of the gas-liquid reaction tank 55, since the carbon dioxide is removed by reaction with leachate mixed with quicklime in the gas-liquid reaction tank 55, very high methane content Will have Therefore, since the combustion in the heat exchanger 57 is smoothly performed, the recovery of thermal energy is facilitated, and since the methane component in the landfill gas is completely burned, the main cause of air pollution is that little methane and carbon dioxide remain. After the combustion of the landfill gas, even if discharged into the atmosphere there is no concern of air pollution.

In addition, the quicklime and the leachate filled in the voids of the contact medium 56 react with the landfill gas passing from the lower part to the upper part. At this time, the quicklime is calcined and then solidified to precipitate out in the contact media 56, and colloidal, floating and soluble substances contained in the leachate are also aggregated to precipitate out in the contact media 56, and remaining leachate Only the gas-liquid reaction tank 55 is drained through the drain port 55c provided at the lower end. That is, during the process of removing carbon dioxide from the landfill gas, the pretreatment process of the leachate is to be automatically performed.

In addition, the leachate pretreated in the gas-liquid reaction tank 55 as described above is supplied to the precipitation tank 58 through the drain port 55c of the gas-liquid reaction tank 55, and the precipitation tank 58 is included in the supplied leachate. It is configured to sediment the sludge that is made and to be treated.

4 is a block diagram of a device for refining landfill gas and leachate pretreatment according to another embodiment of the present invention, as shown, a quicklime storage tank 61, a gas-liquid reaction tank 63, a contact medium 64, and leachate It comprises an injection means, a heat exchanger (65), a coagulant feeder (66), a stirrer (67) and a settling tank (68).

The gas-liquid reaction tank 63 is a cylinder installed on the ground, and is provided such that an air diffuser 62 through which waste landfill gas is sucked and diffused through a lower end portion thereof is provided, and an exhaust hole 63a is provided at one side of the upper end portion. The contact medium 64 is installed in such a way as to cross the inner central portion of the gas-liquid reaction tank 63 in the transverse direction, as in the above embodiment, but a sand layer is used as the material and settles below a certain height of the sand layer. The pore membrane 64a is fixedly installed at the lower and middle ends of the gas-liquid reaction tank 63 in a horizontal direction so as to be prevented from being formed. The contact medium 64 composed of a sand layer as described above has the advantage of being able to suppress the discharge of sulfur oxides by contact removal of sulfur oxides in the landfill gas.

The leachate injection means is a means for filling the quicklime and landfill leachate in the quicklime storage tank 61 to the level where the sand layer is sufficiently submerged in the gas-liquid reaction tank 63, the gas-liquid reaction tank 63 to receive the leachate of the landfill It is composed of a leachate feed pipe 60 is connected to the upper side, and quicklime feeder (61a). The quicklime feeder 61a is configured to supply quicklime to the gas-liquid reaction tank 63 according to the amount of leachate flowing into the gas-liquid reaction tank 63 through the leachate supply pipe 60.

The heat exchanger 65 is configured to recover heat energy while receiving and burning the landfill gas sucked through the exhaust hole 63a of the gas-liquid reaction tank 63. At this time, since the carbon dioxide in the landfill gas, which is diffused from the lower portion of the gas-liquid reaction tank 63 through the acidic gas 62 of the gas-liquid reaction tank 63, is removed by reacting with quicklime, leachate, and sand layer, the heat exchanger 65. The methane content in the landfill gas supplied is very high. Therefore, as in the above embodiment, the combustion in the heat exchanger 65 is made smoothly, and heat energy is easily recovered, and after the landfill gas is burned, there is no fear of air pollution even when discharged into the atmosphere. Will be.

On the other hand, the leachate filled in the gas-liquid reaction tank 63, sedimentation and sedimentation by solidifying the quicklime in response to the added quicklime and the landfill gas passing through, the colloidal, floating and soluble material is agglomerated to the contact medium (64) The sedimentation and removal of the phosphorus sand layer, the remaining leaching means is discharged through the discharge pipe (63b) coupled to the upper side of the gas-liquid reaction tank (63). That is, as in the above embodiment, during the process of removing carbon dioxide from the landfill gas, the pretreatment process of the leachate is to be automatically performed.

The stirrer 67 is installed at one side of the settling tank 68 so that the pretreated leachate discharged from the gas-liquid reaction tank 63 through the discharge pipe 63b is passed before being supplied to the settling tank 68. In addition, the coagulant feeder 66 is configured to supply the coagulant 67 to agglomerate a small amount of suspended and soluble material remaining in the pretreated leachate. That is, while the pretreated leachate discharged through the discharge pipe 63b of the gas-liquid reaction tank 63 stays in the stirrer 67, after being stirred together with the auxiliary coagulant supplied from the auxiliary coagulant supplier 66 It is configured to be supplied to the settling tank (68). In this case, a polyelectrolyte, activated silicic acid or a weighting agent is used as the coagulant.

In the sedimentation tank 68, the sludge component can be sedimented and removed while remaining the leachate supplied for a predetermined time. At this time, a small amount of floating and soluble substances remaining in the leachate by the coagulant is solidified. By sedimentation, the leachate treatment efficiency can be improved.

Landfill gas purification and leachate pretreatment method according to the present invention, as shown in Figure 5, comprises a leachate supply step, landfill gas supply step, reaction step and combustion step, see the configuration of FIG. The description is as follows.

At this time, the operating conditions for each process step was as shown in Table 1.

TABLE 1

The leachate supplying step is a step of supplying the landfill leachate and quicklime into the gas-liquid reaction tank (63) to fill the sand layer, which is the contact medium (64), to a sufficient level. At this time, the landfill leachate is introduced into the gas-liquid reaction tank 63 through the supply pipe 60, the quicklime is in accordance with the amount of the leachate flowing into the gas-liquid reaction tank 63 from the quicklime storage tank 61 from the gas-liquid reaction tank 63 By being supplied with, the leachate mixed with quicklime is filled in the gas-liquid reaction tank 63.

After filling the gas-liquid reaction tank 63 with the leachate mixed with quicklime, the landfill gas supplying step of supplying the landfill gas through the acid gas 62 installed in the lower portion of the gas-liquid reaction tank 63 is performed.

Then, after the landfill gas supplying step, the landfill gas, which is generated from the lower portion of the gas-liquid reaction tank 63, rises, and the reaction step of washing the quicklime with leachate mixed with quicklime causes a chemical reaction.

In this reaction step, the carbon dioxide in the landfill gas reacts with the leachate mixed with quicklime, and calcium carbonate is produced, and during the formation of the calcium carbonate, it reacts with colloidal, floating and some soluble substances in the leachate to solid-liquid separation. After that, the sedimentation is separated into the sand layer which is the contact medium (64). In addition, the quicklime mixed in the leachate is calcined and then separated from the leachate by sedimentation with the alkali in the water to settle into the sand layer, which is the contact medium 64.

The chemical reaction generated in the reaction step is as follows.

The quicklime injected into the gas-liquid reactor 63 is precipitated in combination with alkalinity in the leachate, and during this precipitation reaction, colloidal materials (organic, inorganic), TDS (Total Dissolved Solids) and TFS (Total Fixed Solid) The leachate is treated by coprecipitation with contaminants in the leachate.

CaO + H ₂ O ↔ Ca (OH) ₂

Ca (OH) ₂ + Ca (HCO) ₃ ) ₂ ↔ 2CaCO ₃ + 2H ₂ O

Ca (OH) ₂ + Mg (HCO ₃ ) ₂ ↔ Mg (CO ₃ ) (liq) + CaCO ₃ ↓ + 2H ₂ O

MgCO ₃ + Ca (OH) ₂ ↔ Mg (OH) ₂ + CaCO ₃

The carbon dioxide in the landfill gas undergoes the following reaction with unreacted slaked lime and calcium carbonate. In this process, the elevated pH is decreased by the injection of quicklime and the methane content in the landfill gas increases.

Ca (OH) ₂ + CO ₂ ↔ CaCO ₃ + H ₂ O

CaCO ₃ + CO ₂ + H ₂ O ↔ Ca (HCO ₃ ) ₂

In the present invention, the storage tank 51 in which quicklime is stored, the quicklime and leachate, and the landfill gas are filled with the gas-liquid reaction tank 55 and the inner central portion of the gas-liquid reaction tank transversely for optimum reaction, and have a plurality of pores. It consists of a filter medium (56), a sedimentation tank (58), and a heat exchanger (57) for recovering thermal energy by burning methane of landfill gas, and each of these components is based on the following numerical analysis results. The operating conditions were determined.

When hydroxide ions and calcium ions are dissolved in water, the reaction with carbon dioxide dissolved by blowing carbon dioxide gas is the same as reaction 1) and reaction 2).

Reaction 1)

Reaction 2)

The components A are Ca ²⁺ (aq), B is OH ^- (aq), C is CO ₂ (aq), D is defined as when CaCO ₃ (s), E is H ₂ O (l), any The number of moles of each component at time t is

Where N _A0 is the initial mole number of A, X _A is the conversion rate of A, and F _C0 is the rate at which C is dissolved in buffalo (mol / sec). When F _C0 reaches the solubility of carbon dioxide in water, it no longer melts and carbon dioxide gas is released as it is. If the reaction volume (V) is constant,

Rearranging,

At any time, t, the concentration and reaction rate are

The conversion rate was calculated by integrating Equation (5) using the numerical method using the values of the conditions shown in Table 2 below, and the concentration and reaction rate with respect to time in the reactor from Eqs. (6) to (10). Was calculated. The calculated results are shown in FIGS. 6 to 8.

FIG. 6 is a graph showing the reaction conversion rate of Ca ²⁺ (aq) with respect to time, and the conversion rate is approximately constant after about 1200 sec (20 min). 7 is OH with the components since 1200 sec graph showing the concentration of the reactor ^- is the concentration of the other ingredients except the Ca ²⁺ (aq) the amount of virtually eliminated because the reaction occurs in the (aq) constant. CO ₂ (aq) increases in concentration up to solubility in water and when solubility is reached, CO ₂ gas is not dissolved in water and is released as it is. 8 is a graph showing the change in reaction rate with time, the reaction rate is reduced due to the reduction of reactants in the reactor.

TABLE 2

In the above results, the injection of carbon dioxide at 200 mL / min into the semi-batch reactor at the temperature of 8 ° C., pH 12.56, Color, 306 (357) PtCo, Ca ²⁺ 2,201 mg / l, Mg ²⁺ 1.58 mg / l The conversion rate was nearly constant after about 20 minutes. By using this, it is possible to determine the reaction time and the amount of reactants required for the reaction by calculating the conversion of calcium ions over time in the reactor, the concentration of each component, and the change in reaction rate.

Therefore, the injection rate, injection amount and injection method of leachate and quicklime were determined by the numerical results and Jar test. Injection volume change in the Jar test is in terms of the concentration of Ca ^2+, Mg ²⁺ in the leachate to the alkalinity and, when the pH is neutral all alkalinity is bicarbonate ion (HCO ₃ ^-) bicarbonate ions assumed to exist as (HCO ₃ ^- After calculating the amount of), the equilibrium constant was calculated by Rossum and Merrill's method, and injected based on the theoretical amount determined in consideration of the ionization fraction.

The following are the optimum operating conditions determined when the present invention is applied to the leachate having the characteristics shown in Table 3 as an example. The results of the jar test are shown in FIGS. 9 and 10. 9 shows the experimental results of the treatment efficiency according to the injection amount during the powder injection, and FIG. 10 shows the treatment efficiency according to the injection amount during the injection of the slurry phase.

As shown in the figure, about 26 g / L was injected into the powder phase to obtain about 80% treatment efficiency, but about 16 g / L was injected into the slurry phase. Therefore, it was found that it was more efficient to inject quicklime into the gas-liquid reaction tank as a slurry.

TABLE 3

(Unit: mg / ℓ except pH & xolor (PtCo))

However, in case of quicklime, since the solubility in water is very low, stirring is required to inject it into the reactor in the form of a slurry. Therefore, after quick injection of 0.51b0 of quicklime into 1gal leachate, it is rapidly stirred at 300rpm for 5 minutes, and then agitated at 100-200rpm until it is injected into the reactor.

After the reaction step as described above, the landfill gas discharged through the exhaust hole (63a) of the gas-liquid reaction tank 63 is supplied to the heat exchanger (65), the heat exchanger (65) by burning the landfill gas to heat A combustion step of recovering energy is performed. At this time, since the landfill gas supplied to the heat exchanger 65 has a high methane content by removing carbon dioxide by the chemical reaction as described above, complete combustion in the heat exchanger 65 becomes possible, and thus, thermal energy It is possible to smoothly recover, and after burning the landfill gas, there is no fear of air pollution even when discharged into the atmosphere.

And, as shown in the above chemical reaction formula, the leachate filled in the gas-liquid reaction tank 63 is a chemical reaction in the gas-liquid reaction tank 63 in the state in which the colloidal, floating and soluble substances are aggregated and settled and separated. , And is discharged through the discharge pipe 63b of the gas-liquid reaction tank 63. That is, during the process of removing carbon dioxide from the landfill gas, the leachate pretreatment process for removing colloidal, floating and soluble substances contained in the leachate is automatically performed.

In addition, the reaction step may further include a coagulant addition step and a sludge precipitation step.

In the present invention, the coagulant addition step is a step of removing the sludge of the fine particles which are not separated by the gas-liquid reaction tank 63 by the coagulant. In this step, the leachate from which the colloidal, floating, and soluble substances have been removed by the reaction in the gas-liquid reaction tank 63 is transferred, and then a coagulant is added to precipitate the slurry components contained in the leachate to separate. At this time, the coagulant used to enhance the coagulation effect during the aggregation reaction to strengthen the binding force and to better precipitate.

As such coagulants, active silicic acid, weight and adsorbents, and polymer electrolytes are used. Activated silica hardens the floc and prevents the floc from breaking. The flocs formed are large, dense and settle faster. In addition, it is possible to obtain an effect of enhancing the color removal effect and improving floc formation even at low water temperature. A weight agent is a substance that forms incidental particles that enhance flocculability. There are two types of polymer electrolytes, a natural polymer electrolyte and a synthetic polymer electrolyte. The polymer electrolyte has a very high molecular weight, and when dissolved in water, largely charged ions are generated. Polymeric electrolytes include cationic polyelectrolytes, anionic polyelectrolytes, and nonionic polyelectrolytes.

In the sludge settling step, the leachate to which the coagulant is added through the coagulant addition step is supplied to the settling tank 68 and accommodated for a predetermined time to precipitate and separate the sludge component contained in the leachate. Make sure

On the other hand, in the leachate supply step, as shown in Figure 3, the leachate and quicklime supplied from the landfill is fed from a mixer, the mixture is stirred and mixed, and further comprises a mixing step to be supplied to the gas-liquid reaction tank Of course it can.

As can be seen by the above embodiment, by the apparatus and method for pretreatment of landfill gas and leachate pretreatment according to the present invention, by removing carbon dioxide from the landfill gas, the concentration of methane, which is combustible in the landfill gas, is high. As a result, the landfill gas can be completely burned, and thus, the landfill gas can be completely burned. Accordingly, the landfill gas with a high calorific value can be used as a stable energy source. There is an effect that can prevent the environmental pollution caused by. The purification of landfill gas has the advantage of being able to effectively cope with international greenhouse gas regulations that strictly regulate the emission of carbon dioxide and methane gas.

In addition, the waste leachate reacts with quicklime, and during the process of washing the carbon dioxide of the landfill gas, the colloidal, floating, and soluble substances contained in the leachate are agglomerated and settled in the contact media, thereby leaching out the leachate. The leachate pretreatment process for removing contaminants of the leachate is automatically performed. Accordingly, the leachate aftertreatment process is simplified by reducing the contamination load of the leachate.

In addition, when the sand layer is used as a contact medium installed in the gas-liquid reaction tank, the sulfur oxide in the landfill gas is contacted and removed, thereby preventing the sulfur oxide from flowing into the heat exchanger, which is a thermal energy recovery device. There is an effect that can lengthen the mechanical life of the peripheral device.

The above description has been made of an apparatus and method for refining landfill gas and pre-treatment of leachate according to an embodiment of the present invention, but the present invention is not limited thereto, and waste slag or dust containing a large amount of quicklime in place of the pure quicklime Such modifications and applications will be possible to those skilled in the art in various ways.

Claims (7)

A quicklime storage tank in which quicklime is stored; A gas-liquid reaction tank receiving the landfill gas through one lower side thereof and having an exhaust hole formed at an upper end thereof; A contact medium filling the inner central portion of the gas-liquid reaction vessel transversely and having a plurality of pores; Leachate injection means for supplying the leachate and quicklime through the gas-liquid reaction tank so that the landfill leachate and the quicklime is filled in the voids of the contact medium; A heat exchanger which receives the landfill gas from which carbon dioxide has been removed by reaction with the leachate mixed with the quicklime in the gas-liquid reaction tank through the exhaust hole, and recovers thermal energy by burning a methane component of the landfill gas; And, A precipitation tank for sedimentation and removal of quicklime and coagulation of colloidal, floating and soluble materials by the reaction in the gas-liquid reaction tank to inhale the leachate sedimented and removed in the contact medium, and to sediment and select the sludge contained in the leachate; Apparatus for landfill gas purification and leachate pretreatment comprising a. The method of claim 1, The leachate injecting means comprises: a mixer for receiving leachate generated from the landfill and the quicklime at a constant rate and stirring them; A supply pipe extending from the mixer and penetrating through an upper side of the gas-liquid reaction tank, and having a plurality of injection nozzles formed at a portion extending into the gas-liquid reaction tank; A pump installed at one side of the supply pipe and pumping the leachate mixed with quicklime in the mixer to the gas-liquid reaction tank; Apparatus for landfill gas purification and leachate pretreatment comprising a. According to claim 1, The leachate mixed with the quicklime is filled from the lower end of the gas-liquid reaction tank to the upper portion of the contact medium so that the contact medium is sufficiently submerged; The contact medium is made of a sand layer, and a pore membrane for freezing the settlement of the sand layer is fixed in the horizontal direction at the lower and middle ends of the gas-liquid reaction tank; An apparatus for refining landfill gas and pre-treatment of leachate, characterized in that an acid pipe for discharging and supplying the landfill gas is installed under the gas-liquid reaction tank. The method of claim 1, A stirrer is installed between the gas-liquid reaction tank and the settling tank, and a coagulant feeder is provided to mix the coagulant with the leachate flowing into the stirrer. Apparatus for landfill gas purification and leachate pretreatment, characterized in that it is configured to remove and remove a small amount of colloidal, floating and soluble substances remaining in the aggregate. A leachate supplying step of supplying landfill leachate and quicklime to the gas-liquid reaction tank by using the leachate injecting means so as to be filled in the pores of the contact media; A landfill gas supply step of supplying a landfill gas into the gas-liquid reaction tank through a lower portion of the gas-liquid reaction tank after the leachate supplying step; After the landfill gas supplying step, the landfill gas supplied to the gas-liquid reaction tank passes through the contact medium and reacts with leachate mixed with quicklime, and carbon dioxide in the landfill gas is solidified and separated, and the quicklime is calcined and alkali in water. A reaction step of sedimentation and separation by contact media, and the colloidal, floating and soluble materials of the leachate settle and separation by contact media; And, After the reaction step, after receiving the landfill gas from which carbon dioxide has been removed from the gas-liquid reaction tank to the heat exchanger, a combustion step of burning to generate heat energy; Landfill gas purification and leachate pretreatment method comprising a. The method of claim 5, Wherein the leachate supply step, the landfill leachate and the quick lime is supplied from the mixer, the method for the landfill gas purification and leachate pretreatment, characterized in that it comprises a mixing step of stirring it. The method of claim 5, After the reaction step, the colloidal, suspended and soluble material is removed leachate is transferred to the stirrer, the coagulant addition step of adding a polymer electrolyte, activated silicic acid or a weighting agent as a coagulant, and then stirring; A sludge precipitation step of supplying the leachate to which the auxiliary coagulant is added and precipitating the sludge component; Landfill gas purification and leachate pretreatment method comprising a further.