KR101207532B1 - Apparatus for performing drying and removing impurities process of bio-methane at high purity bio-methane purification system - Google Patents

Abstract

PURPOSE: An apparatus for implementing a biomethane drying and impurity removal process in a high purity biomethane refining facility is provided to stably produce biomethane of high purity and to easily implement the replacing operation of a drying agent in a drying unit. CONSTITUTION: An apparatus for implementing a biomethane drying and impurity removal process includes a compressor(1), a biogas refining column(2), a biogas collecting column(3), an operational water collecting column(4), a drying unit(7), and an operational water circulating pump(5). The compressor compresses anaerobic biogas from organic waste under high pressures. The biogas refining column generates biomethane of high purity. The drying unit removes moisture and impurities from the biomethane containing saturated moisture.

Description

Apparatus for performing drying and removing impurities process of bio-methane at high purity bio-methane purification system}

The present invention relates to a device for performing the drying and impurity removal process of biomethane in a high-purity biomethane purification plant, more specifically methane (CH ₄ ), carbon dioxide (CO ₂ ), hydrogen sulfide (H ₂ S) for the process water 32 mg of biomethane production standard using a drying device and activated carbon that perform dehumidification and regeneration process in a high-purity biomethane refining facility that can purify methane (CH ₄ ) in biogas with high purity Renewable energy fuels such as vehicle fuels and city gas fuels by carrying out a drying process to meet the conditions of / Nm3 and removing residual sulfur as much as 10ppm or less and stably producing high purity biomethane by removing other impurities. The present invention relates to an apparatus for performing a drying and impurity removal process of biomethane.

As is well known, stable supply of energy is essential for the sustainable development of the national economy.

However, in countries with high dependence on overseas energy supply, such as Korea, the development of renewable energy sources that can be procured domestically is very urgent for the instability of energy supply and demand. To this end, Korea has invested enormous resources over the past decades to develop renewable energy.

As the necessity of development of renewable energy sources is increasing, the interest in the energyization of organic waste resources is increasing internationally. Among them, the interest in biogasification of organic wastes is increasing.

In particular, Korea has a large amount of various organic wastes such as food waste, livestock manure and sewage sludge nationwide, but the waste policy has been focused on the treatment of the generated waste, and improper management of treatment facilities is odor and pollution. As it causes pollution and environmental problems, it causes a negative perception of local residents, and a vicious cycle of recognizing environmental infrastructure as a hate facility is repeated, bringing local selfishness such as "NIMBY phenomenon" to bring social issues and There was a problem that appeared as a factor of policy conflict.

In this regard, the Korean government has shifted the paradigm from the concept of simple treatment and physical recycling to the energyization of organic waste resources and promoted effective and efficient waste treatment and energy projects, thereby contributing to the national economy and environmental conservation. Many investments are being made in developing energy-efficient technologies for waste resources, including organic waste resources.

However, in Korea, the current status of anaerobic biogas generated from anaerobic digesters such as sewage treatment plants is mostly used for heating of digesters, and the level of simple incineration using biogas, boilers, and power generation fuels. I'm staying at.

This means that organic waste such as sewage treatment plant, livestock manure, food waste, slaughter residues, etc. is 45 ~ 60% of methane (CH ₄ ) and 25 ~ 50% of carbon dioxide (CO ₂ ) through anaerobic digestion in the absence of oxygen. Biogas is composed of 0-10% of nitrogen (N ₂ ) and trace amounts of hydrogen sulfide (H ₂ S) and ammonia (NH ₃ ). Thus, in addition to methane (CH ₄ ), which is a main component of the biogas, odor causing substances As it contains various volatile organic compounds (VOC) and impurities such as hydrogen sulfide (H ₂ S), due to the effects of the surrounding environment and problems such as corrosion of the device and deterioration of efficiency when used as fuel, proper treatment is required. have.

Therefore, in order to be able to use anaerobic biogas as a natural gas alternative fuel supplied to natural gas automobile alternative fuel, urban gas alternative fuel, renewable energy business, and fuel cell business, 95% of methane (CH ₄ ) in biogas is used. It must be produced with the above high purity, and for this purpose, the high purity biomethane refining facility capable of producing high purity biomethane must be secured, and the technical skills must be secured accordingly.

In recent years, due to the increasing interest in renewable energy in the world, foreign technologies for the use of biogas have secured high-purity methane production technology and are entering the renewable energy industry through reforming using high-purity methane. As described above, since it still remains at a simple level of use such as incineration and boiler fuel using biogas, it is necessary to secure high-purity methane production technology and to invest in high-purity biomethane purification facilities.

Accordingly, the present invention relates to a high-purity biomethane purification process using a water scrubbing method and a purification facility capable of producing methane (CH ₄ ) in biogas at a high purity of 95% or higher using a water scrubbing method suitable for domestic conditions. As an invention researched and developed to provide a biomethane purification process and a purification facility, an object of the present invention is to improve a drying apparatus for performing a dehumidification and regeneration process for drying and removing impurities from biomethane in a high purity biomethane purification facility. Using activated carbon, water 32mg / m3 (standard condition 0 ℃, 1 atm) is applied to 95% or more of methane, which is the standard for producing biomethane, in order to meet the automobile fuel manufacturing standard according to the revised regulation of Environment Directive No.407 of the Environmental Directive. ) Removes the remaining sulfur content as much as 10ppm or less while satisfying the following conditions, The present invention provides a device for performing a process of drying and removing impurities of biomethane, which can stably produce high-purity biomethane by removing other impurities to be used as renewable energy fuel such as vehicle fueling and city gas fuel.

In order to achieve the above object, the present invention provides a compressor for performing a biogas compression process for separating and collecting anaerobic biogas generated from organic waste and compressing it at high pressure, and receiving and absorbing the biogas compressed at high pressure through the compressor. Biogas purification tower that absorbs carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) in biogas through the process water to produce high purity biomethane (CH ₄ ), and carbon dioxide discharged from the biogas purification tower ( A biogas recovery tower that receives the process water absorbed by CO ₂ ) and hydrogen sulfide (H ₂ S) and recovers the biomethane contained in the process water through a biogas recovery process, and the process water that has passed through the biogas recovery tower, separate by intersecting the air supplied to the processing water stripping carbon dioxide (CO _2), hydrogen sulfide (H ₂ S) through the process water recovery step of playing a number of steps A water purification recovery tower, a dryer for performing a biomethane drying process to remove moisture and impurities from biomethane containing saturated water discharged from the biogas purification tower and discharged to the upper portion, and supplied to the biogas purification tower In a high purity biomethane purification facility having a process water cooler capable of cooling process water and a process water circulation pump for circulating and supplying the process water, the dryer consists of two, and the filling inside the dryer is operated from the top. Filled in the order of gravel layer, activated alumina (drying agent), molecular sieve (drying agent), and gravel layer (drying agent), followed by Molecular Sieve layer and activated alumina of the fillers in the dryer. The mixing ratio of the layers is 70 to 80 wt% of Molecular Sieve and 20 to 30 wt% mass ratio of activated alumina It is characterized by providing an apparatus for performing the drying and impurity removal process of biomethane in a high purity biomethane purification plant consisting of.

According to the present invention, a buffer tank for storing high purity biomethane from which moisture and impurities are removed through the dryer is further provided, and hydrogen sulfide (H ₂ S) contained in the high purity biomethane is disposed at the lower end of the buffer tank. It is preferred to have activated carbon for removal below 1 ppm and for removal of other impurities.

According to the present invention, the activated carbon at the bottom of the buffer tank for storing the high-purity biomethane while improving the drying apparatus for performing the dehumidification and regeneration process for drying and removing the impurities of the biomethane in the high-purity biomethane purification facility using the water scrubbing method 32 mg / m3 of water in 95% or more of methane, the standard for biomethane production, in order to meet the standards for automobile fuel production in accordance with some amendments to the Enforcement Regulations of the Environmental Regulations No.407 of the Environmental Regulations. ) It satisfies the following conditions and removes remaining hydrogen sulfide (H ₂ S) to 1ppm or less as well as other impurities to stably produce high purity biomethane, which can be used as renewable energy fuel such as vehicle fuel and city gas fuel. It has an effect.

In particular, according to the present invention, it is possible to greatly improve the regeneration of the desiccant (or adsorbent) in the dryer in the process of drying the biomethane to remove moisture and impurities, it is possible to facilitate the replacement of the desiccant during contamination in the dryer, By separating and arranging activated carbon separately from the desiccant in such a dryer, it serves to remove hydrogen sulfide and other impurities as much as possible, and also has an effect of smoothly replacing the activated carbon itself when the regeneration is poor.

Then, in the pure bio-methane refinery within biogas purification tower according to the invention is within the biogas hydrogen sulfide (H ₂ S) to enable handling even up to 3500ppm, the highly pure bio methane in hydrogen sulfide purified from biogas purifying column (H ₂ S) concentration has the effect of purifying to 10 ppm or less.

1 is a view schematically showing a biomethane purification process in a high purity biomethane purification plant to which the present invention is applied.
2 is a view schematically showing a post-treatment plant used in a biogas compression process in a high purity biomethane purification plant to which the present invention is applied.
Figure 3 is a schematic view showing the internal configuration of the condensate removal device that is part A of the after-treatment treatment facility shown in Figure 2 according to the present invention.
Figure 4 is a graph showing the correlation of carbon dioxide (CO ₂ ) solubility in water applied to the biogas purification tower performing the absorption process in the high-purity biomethane purification plant of the present invention as a correlation between temperature and pressure.
Figure 5 schematically shows the internal configuration of the dryer for performing a drying process of the biomethane in the high purity biomethane purification plant of the present invention.

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

At this time, the thickness of the lines or the size of the components shown in the accompanying drawings for explaining the preferred embodiment of the present invention may be exaggerated or omitted for clarity and convenience of description, according to the reference numerals written in the drawings Terms given are terms defined in consideration of functions in the present invention, which may vary according to the intention or convention of a user or an operator.

1 is a view schematically showing a biomethane purification process in a high purity biomethane purification plant to which the present invention is applied.

As shown in Figure 1, the basic method of the high-purity biomethane purification plant to which the present invention is applied is methane (CH ₄ ) for the process water (or time constant, H ₂ O), using a water scrubbing (Water Scrubbing) method, The solubility difference of carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) is used to purify methane in biogas with high purity.

In other words, the process of the high-purity biomethane purification plant using the water scrubbing method is divided into biogas compression process (S1), absorption process (S2), biogas recovery process (S3), and process water recovery process (S4). , Biomethane drying process (S5) can be largely divided.

1. Biogas Compression Process (S1)

The biogas compression process S1 is performed through the biogas compressor 1. The biogas compression through the compressor 1 thus forms a primary operating pressure condition for removal by the absorption method.

That is, since the biogas flowing into the biogas purification tower 2 to be described later should be supplied at a high pressure, the biogas is compressed at a high pressure through the compressor 1 in the biogas compression process. Compress the gas.

In this case, the compressor 1 may be a reciprocating compressor or a rotary vane compressor, but biogas compression may be configured to variously select the compressor 1 according to the biogas characteristics and the biogas processing capacity. It is configured to operate according to on-site operating conditions.

For example, it is preferable to use a reciprocating compressor under conditions where hydrogen sulfide (H ₂ S) in biogas is 10 ppm or less and biogas flow rate 300 m ³ / hr (under standard conditions 0 ° C. and 1 atm). Saturated water present in is preferably configured to remove saturated water and particulate matter through a Coalesce Filtering System installed in front of the compressor.

In addition, it is preferable to install a buffer tank at the rear end of the reciprocating compressor so as to control the pulsation phenomenon caused by condensate removal and piston compression generated after compression.

On the other hand, it is preferable to use a rotary vane compressor under conditions in which hydrogen sulfide (H ₂ S) in biogas is 10 ppm or more.

This is because, since the compressor body is made of iron, if the concentration of hydrogen sulfide (H ₂ S) in the biogas is high, there is a high risk of damage to the compressor due to corrosion of iron through the following chemical reaction formula.

H ₂ S → H ⁺ + HS-

^{Fe + HS - + H + →} FeS + 2H + 2e - ( if the NH ₃ present)

^(- to increase the amount of ^{_{HS -.) H 2 S +}} NH 3 → NH 4 + + HS

In this case, the hydrogen sulfide (H ₂ S) removal equipment is required to protect the compressor (1), but the operating cost of operating the hydrogen sulfide (H ₂ S) removal equipment is generated.

In general, the dry process used is the activated carbon used as a hydrogen sulfide (H ₂ S) remover is not regenerated, the replacement and operation cost rises, and as the biogas treatment flow rate and hydrogen sulfide (H ₂ S) concentration increases, The replacement operation and the amount of activated carbon used increases, leading to an increase in system operating costs.

Therefore, in order to solve the above problem, it is possible to prevent the occurrence of corrosion by the corrosive gas to the compressor body by supplying a lubricating oil (lube oil), a rotary vane compressor without the pulsation phenomenon which is a disadvantage of the reciprocating compressor This can be solved through the use of.

At this time, the lubricating oil supplied to the rotary vane compressor is separated and processed in the rear end treatment facility 10 in the form of a heat exchanger.

Here, the rear end treatment facility 10 is as shown in FIG.

The rear end treatment facility 10 is a coolant capable of removing the heat of compression generated after biogas compression and a condensate separation tank capable of removing condensate condensed by reducing the temperature, by making an integrated body without connecting an intermediate pipe to separate gas-liquid. It has a structure that can increase the efficiency.

3 shows the inside of the condensate removal apparatus included in the rear end treatment facility 10 of FIG.

That is, the condensate is composed of a mixture of lubricating oil and water, and is configured as shown in FIG. 3 so that the lubricating oil can be separated from the water by the specific gravity difference and discharged. The solenoid valve S is provided through the level sensor LS. It is configured to be discharged through the valve, and the operator is configured to discharge the condensate through the manual valve to minimize the problem caused by the accumulation of condensate in the condensate removal device.

2. Absorption process (S2)

When the biogas is compressed and supplied through the biogas compression process S1, the absorption process S2 is performed in the biogas purification tower 2.

The absorption step (S2) is a process for producing high-purity biomethane by physically absorbing carbon dioxide and hydrogen sulfide in the biogas by the process water (or time constant, H ₂ O) in the biogas purification tower (2).

In other words, the biogas purification tower 2 absorbs carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) in biogas using process water to increase the purity of methane (CH ₄ ) in anaerobic biogas to 95% or higher. To produce.

For example, in the biogas purification tower 2 of the high purity biomethane purification facility to which the present invention is applied, hydrogen sulfide (H ₂ S) in biogas may be processed up to 3500 ppm, and the biogas purification tower 2 may be purified. The hydrogen sulphide (H ₂ S) concentration in the purified high-purity biomethane is less than 10 ppm.

Here, the biogas purification tower 2 is preferably filled with a filler to increase the contact area and the contact time between the process water and the biogas to increase the absorption efficiency.

Absorption is largely dependent on the degree of gas-liquid contact provided in the purification column (or absorption tower) because carbon dioxide absorption usually occurs when a gas containing carbon dioxide comes into contact with a liquid absorption solution. Currently there are many different types of columns developed for the purpose of separation.

That is, the filler filled in the biogas purification tower 2 is to use any of the most commonly used (Random Packing) or regular packing (Structured Packing).

Filler filled in the biogas purification tower (2) exhibits a high top height, it is preferable to select a product excellent in mechanical strength and wear resistance, the selection of the filler can be configured and applied according to the biogas throughput and site conditions It is.

In addition, the filler has a close relationship with the carbon dioxide absorption rate, it is preferable to configure and apply according to the biogas throughput and site conditions.

On the other hand, the water scrubbing method requires a high pressure as a physical absorption reaction of the process water to water, but the most important process factors are the air temperature and the water temperature.

In particular, it is necessary to appropriately adjust the operating pressure and the operating temperature as can be seen that the absorption rate of carbon dioxide in the biogas greatly varies depending on the temperature and pressure to be described later.

At this time, the pressure can be sufficiently lowered mechanically through the same facility as the compressor (1) in the aforementioned compression process, it is preferable to control the temperature of the water through a separate cooling system. Therefore, the high purity biomethane purification facility using the water scrubbing method to which the present invention is applied has a process water cooler 6.

In other words, Korea has four seasons, so we can guarantee good performance in maintaining the temperature of the process water that is needed in the winter season, but since it shows a temperature close to 40 ℃ in the summer season, it may cause problems in maintaining the performance of the process water. In this regard, in order to solve the temperature problem of the biogas purification tower 2, it may be desirable to insulate and insulate the biogas purification tower 2, and to provide a cooling system for an additional cooling process.

The biogas purification tower (2, Scrubber) designed in connection with the cooling system that can control the temperature of the process water is configured to distribute the process water evenly through the distributor having a distributor disposed at the top. .

Here, the operation of the biogas purification tower 2 is preferably operated under the following operating conditions in consideration of the required power cost and manufacturing cost.

It is preferable that the operating pressure of the biogas purification tower 2 is 6-9 barg, and the operating temperature (process water temperature) is 5-8 ° C., and the operating temperature is controlled by using the process water cooler 6. And, the process water circulation is made through the process water circulation pump (5).

In this case, the process water whose temperature is controlled by the process water cooler 6 is supplied to the biogas purification tower 2 through the process water circulation pump 5.

In addition, a distributor is installed at the upper portion of the biogas purification tower 2 to distribute the biogas purification tower 2 evenly through the distributor.

Process water in which carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) are dissolved through the absorption process (S2) by the process water is discharged to the biogas purification tower 2, and the biogas purification tower ( The biomethane purified in 2) is produced in a saturated moisture state after removing the moisture in the biomethane through the demister installed on the biogas purification tower (2).

At this time, the process water discharged from the biogas purification tower 2 is recovered through the biogas recovery process (S3) and the process water recovery process (S4), 95% discharged to the upper biogas purification tower (2) Since the saturated water is contained in the high-purity biomethane, the biomethane drying step (S5) of drying the water through the dryer 7 is performed.

Detailed description of the biogas recovery step (S3), the process water recovery step (S4) and the biomethane drying step (S5) will be described later.

On the other hand, Figure 4 shows the solubility of carbon dioxide (CO ₂ ) in water in relation to the absorption process (S2) made in the biogas purification tower (2) as a correlation between the temperature, pressure change.

The solubility of gas in water increases as the pressure increases, and as temperature decreases, as shown in FIG. 4, the difference in solubility according to temperature change does not appear much in the low pressure range, but as the pressure increases, The range of gas solubility shows a big difference, and it turns out that the conditions above atmospheric pressure conditions are efficient in the operation of the biogas refinery tower 2.

3. Biogas recovery process (S3)

The process water discharged from the biogas purification tower 2 is recovered and circulated through the biosinger recovery process S3 and the process water recovery process S4 described later.

Here, the biogas recovery step (S3) is a step of increasing the recovery rate of the biomethane by the biogas recovery tower (3).

That is, the process water discharged from the biogas purification tower 2 is supplied to the biogas recovery tower 3 before supplying to the process water recovery tower 4.

The biogas recovery tower 3, also called a flash tank, is operated at a lower pressure than the biogas purification tower 2 and higher than the process water recovery tower 4.

The bio-gas recovery container (3) of the process is recovered through the reduced pressure processing water absorbed methane (CH _4), methane (CH ₄₎ is configured to minimize the loss to improve the methane recovery rate of more than 97% from It will play a role.

The gas (methane) recovered from the biogas recovery tower 3 is supplied to the inlet of the biogas compressor 1, compressed again, and then sent to the biogas purification tower 2.

4. Process water recovery process (S4)

In addition, the process water discharged from the biogas recovery tower 3 is supplied to the upper portion of the process water recovery tower 4 in order to perform the process water recovery step (S4).

That is, the process water recovery process S4 is a process of recovering process water by the process water recovery tower 4.

The process water recovery tower (4), also known as an air-stripper, serves to recover and recover process water.

That is, the process water supplied to the upper portion of the process water recovery tower 4 is evenly distributed into the process water recovery tower 4 through the distributor installed in the upper portion and is supplied to the lower portion of the process water recovery tower 4.

The process water recovery tower 4 is operated at atmospheric pressure, and the air sucked in from the lower side of the process water recovery tower 4 and the process water supplied from the upper cross each other to produce carbon dioxide (CO ₂₎ in the process water. ), Hydrogen sulfide (H ₂ S) is degassed, degassed carbon dioxide (CO ₂ ), hydrogen sulfide (H ₂ S) is discharged through the air stream, and the process water is recovered by the regeneration process in the process water.

At this time, as the filler is filled in the biogas filling tower 2, the filling is also filled in the process water recovery tower (4) to increase the degassing efficiency by increasing the contact area of the process water and air. do.

The process water, which has been regenerated in this way, is discharged from the process water recovery tower 4 and supplied to the process water circulation pump 5, thereby performing a continuous circulation process.

5. Biomethane Drying Process (S5)

The biomethane purified from the biogas purification tower 2 is produced in a saturated moisture state after removing the moisture in the biomethane through a demister (not shown) installed above the biogas purification tower 2, At this time, the biomethane in saturated water at the operating temperature of 5 to 8 ° C. and the operating pressure of 6 to 9 barg of the biogas purification tower 2 is removed such that more than 90% of the saturated water in the biomethane is removed through a filter. do.

However, the biomethane drying step (S5) is added to meet the conditions of 32 mg / m3 or less (standard standard 0 ° C., 1 atm) of biomethane production standards.

That is, it is classified into a pressure swing adsorption (PSA) using pressure as an operating variable or a temperature swing adsorption (TSA) using temperature as an operating variable to remove water saturated in high purity methane gas. The biomethane drying process (S5) through the dryer (7) to which the gas separation technology is applied.

Here, the dryer 7 applied to the present invention is a dryer to which a pressure circulation process (PSA) is applied, and the characteristics of the mixed gas using the difference in the adsorption equilibrium caused by the pressure circulation in the system in the system consisting of the adsorbent and the mixed gas are characterized by It is a drying device applying gas separation technology to selectively separate components.

In particular, the dryer 7 to which the present invention is applied is filled with activated alumina, which is a desiccant (or adsorbent) having a good water absorption rate, and a Molecular Sieve (trade name), which is a zeolite series.

That is, when looking at the structure of the filler in a more specific biomethane dryer to which the present invention is applied, as shown in Figure 5, from the top of the dryer (7), the gravel layer (11), the active alumina layer (12, Activated Alumina) as a drying agent, The other desiccant is filled in the order of Molecular Sieve (13) and Gravel (11).

At this time, the mixing ratio of the filler in the dryer 7 is preferably composed of a mass ratio of 70 ~ 80wt% Molecular Sieve, activated alumina (Activated Alumina) 20 ~ 30wt%.

In addition, the filling of the filling is configured to form a layer not to be mixed with each other.

Here, the gravel layer 11 is respectively filled in the upper and lower portions of the dryer 7 serves to prevent the phenomenon of drift in the dryer 7 and the mixing of the desiccant due to the air flow and leakage of the pipe.

In addition, the activated alumina layer 12 serves to perform removal of residual oil mist and primary moisture in biomethane produced through the biogas purification tower 2, and to remove the mole curive sieve ( Molecular Sieve) layer 13 serves to produce high purity biomethane having moisture content suitable for fueling through secondary water removal and adsorption removal of carbon dioxide.

Here, prior to dehumidification with the zeolite-based Molecular Sieve layer 13, the first dehumidification is performed with the activated alumina layer 12. Because of the disadvantage of having a large effect, when there is a lot of moisture, the adsorption amount of carbon dioxide decreases as well as the regeneration of the desiccant decreases with the adsorption of moisture, thereby regenerating the desiccant (adsorbent) in the dryer 7 while minimizing the influence of moisture. To improve the quality.

At this time, the dryer 7 is operated in two, when one column is dehumidifying operation, the other column is in the operation preparation stage through the regeneration process of the desiccant for operation.

As such, the biomethane drying process S5 through the dryer 7 is performed through dehumidification of the desiccant (or adsorbent), and the dehumidification process is dehumidification in the biomethane through the desiccant (adsorbent) in the dryer 7. .

The dehumidification is carried out by controlling the operating pressure of the high-purity biomethane production facility is configured to maximize the dehumidification efficiency.

In particular, according to the present invention, the dew point in the biomethane passed through the dryer 7 is below -80 ° C (moisture content 0.6 mg / m 3, standard reference 0 ° C, under 1 atm).

In addition, the desiccant regeneration process in the two-dried dryer 7 recovers some of the biomethane having a dew point of -80 ° C. or lower produced through the drier 7 and regenerated in the biomethane dryer 7. It will be used as a gas.

At this time, the regeneration gas is heated to 120 ~ 200 ℃ through a heater before supply to the dryer is supplied as a regeneration gas in the biomethane dryer (7).

In addition, the regeneration process is configured to proceed under high temperature and depressurization operation conditions, and is configured to facilitate desorption of moisture adsorbed on the desiccant surface filled in the dryer 7 through reduced pressure.

Of course, the operation and regeneration time of the biomethane dryer 7 is generally 6 to 12 hours, depending on the driver and site conditions.

The biomethane produced through the dryer 7 is stored in the rear purified biomethane buffer tank 8.

The purpose of having the buffer tank (8) is to perform the role of the buffer tank (8) required for fueling the biogas vehicle and the use of city gas mixed fuel.

In particular, it is preferable to further install activated carbon 9 at the lower end of the buffer tank (8).

The activated carbon 9 installed at the bottom of the buffer tank 8 performs a function of removing hydrogen sulfide (1 ppm or less) and other impurities remaining in the biomethane, so that more stable high-purity biomethane can be produced.

In particular, by arranging the activated carbon (9) separately from the desiccant of the dryer (7), when the desiccant contamination in the biomethane dryer (7) due to the occurrence of abnormal conditions during operation of the dryer is configured to facilitate the replacement operation thereof I'm doing it.

In addition, the activated carbon 9 has a hydrophobic property, so that the adsorption amount of moisture is low at low relative pressure (gauge pressure), and thus it is not affected by moisture. As it has a disadvantage of not being able to be separated, it is separated and arranged to remove hydrogen sulfide and other impurities from the bottom of the buffer tank (8) as much as possible, and when the activated carbon 9 is contaminated, it can be smoothly replaced. I'm doing it.

Although the above has been shown and described with respect to preferred embodiments of the present invention, the present invention is not limited to the above-described embodiment, it is usually in the field to which the present invention belongs without departing from the spirit of the invention claimed in the claims. Anyone skilled in the art can make various modifications, as well as such modifications that fall within the scope of the appended claims.

1: compressor 2: biogas purification tower
3: biogas recovery tower 4: process water recovery tower
5: process water circulation pump 6: process water cooler
7: dryer 8: buffer tank
9: activated carbon 10: back end treatment facility
11: gravel 12: activated alumina
13: Molecular Sheave S: Solenoid Valve
LS: Level Sensor S1: Biogas Compression Process
S2: Absorption Process S3: Biogas Recovery Process
S4: process water recovery process S5: biomethane drying process

Claims (2)

Compressor (1) to perform the biogas compression process (S1) for separating and collecting the anaerobic biogas generated from the organic waste and compressed to high pressure, and receives the biogas compressed at high pressure through the compressor (1) Biogas purification tower (2) for absorbing carbon dioxide (CO ₂ ), hydrogen sulfide (H ₂ S) in the biogas as a process water through S2) to produce high purity biomethane (CH ₄ ), and the biogas purification tower ( 2) A biogas recovery tower (3) for recovering biomethane contained in process water through a biogas recovery process (S3) by receiving process water absorbed from carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) emitted from ₂ ). And cross-process water supplied through the biogas recovery tower 3 and air supplied separately to degas carbon dioxide (CO ₂ ) and hydrogen sulfide (H ₂ S) in the process water through the process water recovery process (S4). A process water recovery tower 4 for regenerating water, Dryer 7 for performing a biomethane drying step (S5) to remove moisture and impurities from the biomethane containing saturated water discharged to the upper portion produced in the biogas purification tower (2), and the biogas purification In the high-purity biomethane purification facility having a process water cooler (6) capable of cooling the process water supplied to the tower (2) and a process water circulation pump (5) for circulating and supplying the process water,
The dryer 7 is composed of two, and the filler inside the dryer (7) from the top of the gravel layer 11, the active alumina layer (12, Activated Alumina) as a drying agent, the Molecular Sheave layer (13) as another drying agent , Molecular Sieve, and gravel layer 11 are filled in this order, and the mixing ratio of the Molecular Sieve layer 13 and the activated alumina layer 12 among the fillers in the dryer 7 is Molecular Sieve. (Molecular Sieve) A device for performing the drying and impurity removal process of biomethane in a high-purity biomethane refining plant, characterized in that consisting of 70 ~ 80wt%, 20-30wt% mass ratio of activated alumina (Activated Alumina). The method of claim 1,
A buffer tank 8 for storing high purity biomethane from which moisture and impurities are removed through the dryer 7 is further provided, and at the bottom of the buffer tank 8, hydrogen sulfide (H ₂ S) contained in the high purity biomethane. ) Is a device for performing the drying and impurity removal process of biomethane in a high-purity biomethane refining facility, characterized in that the activated carbon (9) for removing less than 1ppm and other impurities.

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