KR20170079733A - An Apparatus for Removing Humidity in Biogas - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing moisture from a biogas, and more particularly to a device for removing moisture from a biogas by a membrane filter. The apparatus for removing moisture of biogas includes a supply unit (12) for regulating the supply amount of biogas supplied from the outside; A primary filter unit (13) connected to the supply unit (12) to remove fine particles and moisture from the biogas; A condensing unit (14) for condensing water contained in the biogas transferred from the primary filter unit (13); And a secondary filter unit (15) for removing residual water and fine particles contained in the biogas transferred from the condensing unit (14), wherein the primary filter unit (13) comprises a gravel filter, The filter unit 15 becomes a PTFE coated membrane filter.

Description

TECHNICAL FIELD [0001] The present invention relates to an apparatus for removing moisture from a biogas,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing moisture from a biogas, and more particularly to a device for removing moisture from a biogas by a membrane filter.

The biogas generated in the digestion process of anaerobic material such as sewage sludge, livestock manure or food wastes may contain water as a main component of methane or carbon dioxide and may further contain gas such as hydrogen sulfide or siloxane. In order for biogas to be used as an industrial fuel such as boiler fuel or power generation fuels, harmful components such as moisture, hydrogen sulfide, or siloxane contained in the biogas need to be removed. For example, And specifies the fuel conditions. The predetermined fuel condition according to the use of the biogas can be determined by the amount of the gas contained in the biogas. As a result, the biogas refining facility and operation become a major factor for maintaining the durability of the generator and improving the economical efficiency of the biogas, and various techniques for removing moisture or gas components from the biogas are known in the art.

Patent Publication No. < RTI ID = 0.0 > 10-2012-0107264 < / RTI > discloses a knockout drum for receiving and temporarily storing collected biogas and removing saturated water condensed in the drum to remove condensed water. A first filter for passing moisture removed biogas through the knock-out drum to remove impurities; A booster for compressing the biogas having passed through the first filter to a pressure suitable for power generation and sending the biogas; A cooler for cooling the biogas compressed by the booster to cool the biogas with a biogas having a temperature suitable for power generation, and condensing moisture contained in the biogas to convert it into condensed water; A separator for separating the biogas and the condensed water by centrifugal force and for removing water-soluble impurities present in the biogas by rotating together the biogas cooled and the converted condensed water through the cooler; A second filter for passing the biogas separated by the separator to remove impurities; And a feedback unit for measuring the state of the biogas separated from the separator and sending out the biogas to the booster when it is determined that the state is not suitable for the power generation.

Patent Registration No. 10-0985912 discloses a biosensor comprising: a water adsorption unit including a pair of adsorption columns packed with an adsorbent, for supplying biogas to one adsorption column to adsorb moisture in the biogas through an adsorbent; And a warming part for warming a part of the dry biogas discharged from any one of the adsorption columns, and supplying the heated biogas to the other adsorption column through the warmed part to remove moisture adsorbed on the adsorbent A biogas moisture removal device including an adsorbent regeneration unit is disclosed.

Patent Registration No. 10-1493731 discloses a biosensor comprising: a body installed in a transfer line for allowing biogas to pass therethrough; A multi-division passage portion formed in the main body such that a plurality of biogas are divided into a plurality of pass holes so as to pass therethrough; And a cooling portion provided around the multi-division passing portion and passing through the cooling water for heat exchange with the biogas.

The moisture removal device disclosed in the prior art is complicated in structure of the apparatus and difficult to completely remove moisture. It is advantageous to have a structure in which the selection of an appropriate filter structure and temperature or gas flow are controlled for the removal of moisture or harmful gas components contained in the biogas. For example, it is advantageous that the water can be removed by adjusting the pore of the filter appropriately. However, the prior art does not disclose a filter structure that allows moisture removal in this manner.

The present invention has been made to solve the problems of the prior art and has the following purpose.

Prior Art 1: Patent Publication No. 10-2012-0107264 (published by GNC Energy, October 02, 2012) Biogas pretreatment apparatus and method for removing moisture contained in biogas using the same Prior Art 2: Patent Registration No. 10-0985912 (issued by Hansol EME Co., October 08, 2010), a biogas moisture removal device Prior Art 3: Patent Registration No. 10-1493731 (Unique ENG Co., Ltd., announced on February 16, 2015) Rapid moisture removal device for biogas

An object of the present invention is to provide an apparatus for removing moisture of a biogas that allows moisture contained in the biogas to be removed to a level suitable for the use conditions by removing water by a membrane filter.

According to a preferred embodiment of the present invention, the apparatus for removing moisture of biogas comprises a supply unit for regulating the supply amount of biogas supplied from the outside; A primary filter unit connected to the supply unit for removing fine particles and moisture from the biogas; A condensing unit for condensing moisture contained in the biogas transferred from the primary filter unit; And a secondary filter unit for removing residual moisture and fine particles contained in the biogas transferred from the condensing unit, wherein the primary filter unit comprises a gravel filter and the secondary filter unit is a PTFE coated membrane filter .

According to another preferred embodiment of the present invention, the condensing unit comprises a heat condensing exchanger and a condenser connected to the heat condensing exchanger.

According to another preferred embodiment of the present invention, the washing apparatus further comprises a washing unit connected to a discharge tube through which the condensation component of the biogas is discharged for washing the primary filter unit or the secondary filter unit.

According to another preferred embodiment of the present invention, two detection units are provided between the condensation unit and the secondary filter unit, and the information detected by the two detection units is transmitted to the control unit to adjust the temperature of the condensation unit.

According to another preferred embodiment of the present invention, the PTFE coated membrane filter is a membrane filter in which glass fibers are coated with PTFE on at least one surface, and the pores of the PTFE have an average diameter of 10 to 60 μm And the thermal expansion coefficient is 10 × 10 -3 / K to 10 × 10 -6 / K at a temperature of 100 to 200 ° C.

The water removal device according to the present invention has a simple structure, and the water removal efficiency is improved by applying a membrane filter while being easy to install. By appropriately selecting the pores of the membrane filter, it is possible to produce biogas having a condition suitable for use. Also, by detecting the pressure between the membrane filters, the flow of the biogas is regulated to increase the removal efficiency of the harmful gas including moisture. In addition, the water removal device according to the present invention makes it possible to treat biogas of various kinds or uses by appropriately designing a filter or a cooling unit.

Fig. 1 is a block diagram showing an embodiment of an overall structure of a water removal device according to the present invention.
Fig. 2 shows a specific embodiment of the moisture removal device according to the present invention.
FIG. 3 shows an embodiment of the process of removing moisture in the moisture removal apparatus according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the accompanying drawings, but the present invention is not limited thereto. In the following description, components having the same reference numerals in different drawings have similar functions, so that they will not be described repeatedly unless necessary for an understanding of the invention, and the known components will be briefly described or omitted. However, It should not be understood as being excluded from the embodiment of Fig.

Fig. 1 is a block diagram showing an embodiment of an overall structure of a water removal device according to the present invention.

1, the apparatus for removing moisture of biogas according to the present invention includes a supply unit 12 for regulating the supply amount of biogas supplied from the outside; A primary filter unit (13) connected to the supply unit (12) to remove fine particles and moisture from the biogas; A condensing unit (14) for condensing water contained in the biogas transferred from the primary filter unit (13); And a secondary filter unit (15) for removing residual water and fine particles contained in the biogas transferred from the condensing unit (14), wherein the primary filter unit (13) comprises a gravel filter, The filter unit 15 becomes a PTFE coated membrane filter.

The overall operation of the moisture removal device can be controlled by the control unit 11 and can regulate the amount of biogas supplied by the supply unit 12. For example, the supply unit 12 may be provided with a control valve capable of adjusting the opening / closing level, and the opening / closing level can be adjusted by the control unit 11. [ The supply unit 12 may be connected to the one filter unit 13 by a transfer conduit and the one detection unit S1 such as a differential pressure sensor may be disposed on the supply unit 12 or the transfer conduit. And the amount of biogas supplied by the supply unit 12 can be adjusted according to the pressure measured by the differential pressure sensor. 1 filter unit 13 may comprise, for example, a gravel filter or a polytetrafluoroethylene (PTFE) coated membrane filter. The gravel filter may be made of gravel having a diameter of, for example, 1 to 20 mm, and may be formed of a layer having a thickness of 0.1 to 100 mm. If necessary, the gravel filter may comprise a plurality of layers and may include a sand filter layer. Specifically, the gravel filter can allow the biogas to pass from the lower side of the gravel filter to the upper side, and the filter layer can be formed so that the average particle size decreases from the lower side to the upper side. And a sand filter layer having an average thickness of 0.1 to 10 mm at the uppermost position.

Gravel filters can be components such as basalt, sandstone, quartzite, granite, elvanite or zeolite, which have high water absorption capacity or pores inside. The gravel filter can remove, for example, foreign matter such as dust or dust contained in the biogas and moisture in the form of droplets. The primary filter unit 13 may comprise, for example, a PTFE membrane filter coated with PTFE on borosilicate glass fibers. The PTFE membrane filter can remove foreign matter and moisture of 0.3 μm or more. The biogas in which dust, dust, droplets, or moisture of a predetermined size or more are removed by the primary filter unit 13 can be transferred to the condensing unit 14 through the transfer conduit. And the water contained in the biogas can be condensed in the condensing unit (14). The condensing unit 14 can be made in a heat exchanger structure and can be connected to a cooler to circulate the refrigerant. The biogas from which water has been removed by the condensing unit 14 is transferred to the secondary filter unit 15 so that the residual moisture can be completely removed.

A second detection unit S2 such as a differential pressure sensor or a temperature sensor may be disposed between the condensing unit 14 and the secondary filter unit 15. [ 2 The information detected in the detection unit S2 can be transmitted to the control unit 11. [ And the control unit 11 can adjust the supply amount of the supply unit 12 or the temperature of the condensation unit 14 based on the transmitted information.

The secondary filter unit 15 may be made of PTFE coated glass fiber coated with glass fiber. For example, a PTFE foam having a thickness of 0.05 to 1.0 mm may be formed on at least one surface of a glass fiber substrate having a thickness of 0.2 to 1.5 mm. Coated PTFE coated glass fiber filter. And moisture of 0.3 m or less can be removed by the secondary filter unit 15. The biogas in which the water has been completely removed by the secondary filter unit 15 can be discharged through the discharge unit 16. A 3-detection unit (S3) for measuring the temperature and the humidity is disposed in the discharge unit (16) as needed, and the biogas temperature and humidity discharged therefrom can be measured and transmitted to the control unit (11).

The liquid components generated in the process of removing moisture or foreign matter from the biogas can be discharged to the outside through the drain tubes T1, T2 and T3, and the drain tubes T1, T2 and T3 are, for example, (13), the condensing unit (14) and the secondary filter unit (15). And it is necessary to clean the primary filter unit 13 or the secondary filter unit 15 to remove the collected foreign matter after the filter unit 15 has been used for a certain period of time. A cleaning unit 17 for cleaning can be installed, and the cleaning unit 17 can be composed of a pump and a spray. The cleaning unit 17 may be connected to the drainage tubes T1, T2 and T3 and may be connected to the drainage tube T2 connected to the condensation unit 14, for example. Water discharged through the drainage tube T2 may be supplied as a spray through a pump to be used for cleaning the primary filter unit 13 or the secondary filter unit 15.

The temperature and permeation pressure of the primary filter unit 13, the secondary filter unit 15, or the condensation unit 14 from which moisture is removed from the biogas need to be appropriately adjusted. A temperature regulating means for regulating the temperature of the primary filter unit 13 or the secondary filter unit 15 may be disposed and the temperature of the condensing unit 14 is regulated by the temperature of the refrigerant circulated by the cooler . Various temperature control means can be arranged in the moisture removal apparatus according to the present invention.

Fig. 2 shows a specific embodiment of the moisture removal device according to the present invention.

2, the primary filter unit may be composed of a gravel filter 231 and a primary membrane filter 232, and the gravel filter 231 may be made of the same or similar structure as described above. And the primary membrane filter 232 may be a PTFE coated glass fiber filter and optionally installed as required. For example, when the biogas contains many foreign substances, the primary membrane filter 232 may be disposed. The moisture-containing biogas can be supplied through the supply conduit and is provided between the gravel filter 231 and the primary membrane filter 232 when the primary membrane filter 232 is installed, And a secondary pressure sensor S12 may be disposed. The condensed water in the gravel filter 231 and the primary membrane filter 232 can be discharged to the outside through the primary drain conduit T1 and the secondary drain conduit T2. As described above, pressure information measured at the first and second pressure sensors S11 and S12 can be transmitted to the control unit. The control unit can adjust the supply rate of the biogas based on the transmitted detection information. Also, the cleaning timing of the primary membrane filter 232 can be determined based on the value measured in the secondary pressure sensor S12, and the time of cleaning of the secondary membrane filter 25 can be determined based on the value measured in the tertiary pressure sensor S13. The cleaning time can be determined. Dust, dust, droplets, or moisture having a diameter of 0.3 μm or more are removed from the gravel filter 231 or the primary membrane filter 232, and the biogas is sent to the heat condensing exchanger 24 corresponding to the condensing unit Lt; / RTI > The water contained in the biogas can be condensed by the heat condensation exchanger 24 to be made into a liquid state. The thermal condensation exchanger 24 may be connected to the cooler 241 and the thermal condensation exchanger 24 and the cooler 241 may be connected by the circulation conduit CT. Water contained in the biogas can be condensed by water, alcohol or a suitable liquid or gas refrigerant flowing through the circulation conduit (CT), and the biogas is passed through the second membrane filter 25 through the third transfer conduit P3 And can be discharged through the tertiary drain conduit T3. And the biogas in which the moisture has completely been removed can be discharged to the outside through the fourth transfer conduit P4. Each of the one, two, three or four transfer conduits P1, P2, P3, P4 connecting the different processing units can be made in the same or similar structure. Water for washing, such as water, may be supplied through the cleaning unit 27 to clean the primary membrane filter 232 or the secondary membrane filter 25. The cleaning unit 27 may include a solenoid valve 271 whose operation is controlled by the control unit 11.

A temperature sensor S21 is disposed between the thermal condensation exchanger 24 and the secondary membrane filter 25 so that the temperature of the biogas transferred from the thermal condensing exchanger 24 can be measured. And the operating condition of the cooler 241 may be determined according to the measured temperature. Further, three detection units (S3) capable of measuring temperature and humidity can be installed on the four-conveying conduit (P4) and the temperature and humidity of the biogas to be discharged can be measured and transmitted to the control unit (11). The feed rate of the biogas can be adjusted according to the transmitted information. At least one pump unit 28 may be provided for the discharge of condensed water, the transfer or discharge of biogas, or the supply of water.

As described above, the primary membrane filter 232 or the secondary membrane filter 25 can be a PTFE-coated glass fiber filter, and the glass fiber can be, for example, a borosilicate. For the production of PTFE-coated glass fibers, for example, a glass fiber substrate having a thickness of 0.2 to 1.5 mm may be coated with PTFE foam at a thickness of 0.05 to 1.0 mm on at least one side. The coating of the glass fiber substrate by the PTFE in the form of foam can prevent the penetration of the PTFE into the glass fibers. However, PTFE can be coated on glass fiber substrates in various forms and it is not necessarily coated on at least one side of glass fiber in the form of PTFE foam. The average pore size of the PTFE foam can be controlled in thickness or in the manufacturing process, for example, the average diameter of the pores of the PTFE is 10 to 60 탆, and the thermal expansion coefficient is 10 x 10 -3 / K to 10 10 -6 / K. The properties of the PTFE-coated glass fiber filter can be determined in various ways, and the primary membrane filter 232 and the secondary membrane filter 25 can be made to have different pore sizes or thicknesses. PTFE-coated glass fibers may, for example, both the pressure drop in the filter can be a 1.0 to _{6.0 ㎜H 2 O / ㎝ / sec} . Or the filter transmittance may be set to be 4.0 to 7.0 cm 3 / cm 2 / sce. If the pore size or permeability is smaller than the suggested value, the removal efficiency may be reduced and the flow of the biogas may be obstructed. If the pore size is larger than the indicated value, the water may not be sufficiently removed. The primary membrane filter 232 and the secondary membrane filter 25 may have different physical properties and the temperature control unit may be installed in the primary membrane filter 232 or the secondary membrane filter 25. Each membrane filter 232, 25 may also be a multilayer filter, for example a multilayer filter having different thicknesses or pore sizes.

The membrane filters 232 and 25 can be made in various structures, and the present invention is not limited to the embodiments shown.

The operation of the water removal apparatus according to the present invention having such membrane filters 232 and 25 will be described below.

FIG. 3 shows an embodiment of the process of removing moisture in the moisture removal apparatus according to the present invention.

Referring to FIG. 3, the method for removing water according to the present invention includes the steps of (P31) introducing biogas; A step P32 of removing a primary foreign matter such as dust or dust from the introduced biogas; A step in which the biogas from which the first foreign matter is removed is condensed by heat in a heat exchange manner (P33); A second foreign matter removing step (P34) in which condensed moisture is collected; A step (P35) in which a pressure change is detected in the first foreign substance removing process or the second foreign substance removing process; Determining whether the biogas feed rate is calculated by the control unit based on the detected pressure and whether the pressure decrease between two different points is within a predetermined range; And a step (P37) in which the filter is cleaned or the supply pressure is adjusted according to the determination of the pressure reduction, and the PTFE-coated glass fiber can be used in the primary foreign matter removal process or the secondary foreign matter removal process.

The foreign matter may be dust, dust, moisture or other gas components, and a PTFE-coated glass fiber filter may be used for primary foreign matter removal or secondary foreign matter removal. The water discharged from each foreign material removal process can be discharged through an appropriate drain pipe, filtered as needed, and used for cleaning the filter. The filter is advantageously kept at a low temperature so that water contained in the biogas is condensed during the collection process. For this purpose, it is possible to allow the cooling water to flow around the filter for removing the primary foreign matter or for the removal of the secondary foreign matter, or to allow the low temperature gas to flow.

A control unit may be installed for operation of the entire apparatus, and the pressure between two different points or filter units may be measured by the detection unit (P36). If the pressure reduction between the filters is within a predetermined range (NO), the pressure can be periodically measured and transmitted to the control unit. On the other hand, if the pressure exceeds the predetermined range, the filter may be cleaned or the supply pressure may be adjusted (P37).

The PTFE coated glass fiber filter can be made, for example, by thermally bonding a PTFE membrane or a thin film to a fiber glass surface or by coating a glass fiber surface with a PTFE foam solution. The PTFE-coated glass fiber has an advantage that the dust collecting efficiency is high with respect to the wettable foreign matter or the fine foreign matter, and the permeability is maintained while the clogging phenomenon is reduced due to the deodorizing effect.

Foreign matter containing moisture from the biogas can be removed in various ways, and the present invention is not limited to the embodiments shown.

The water removal device according to the present invention has a simple structure, and the water removal efficiency is improved by applying a membrane filter while being easy to install. By appropriately selecting the pores of the membrane filter, it is possible to produce biogas having a condition suitable for use. Further, by detecting the pressure between the membrane filter and regulating the flow of the biogas, the removal efficiency of harmful gas including moisture is increased. In addition, the water removal device according to the present invention makes it possible to treat biogas of various kinds or uses by appropriately designing a filter or a cooling unit.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention . The invention is not limited by these variations and modifications, but is limited only by the claims appended hereto.

11: control unit 12: supply unit
13: 1 filter unit 14: condensing unit
15: secondary filter unit 16: exhaust unit
17: cleaning unit 24: thermal condensing exchanger
25: Secondary membrane filter 27: Cleaning unit
28: Pump unit 231: Gravel filter
232: primary membrane filter 241: cooler
271: Solenoid valve P1, P2: 1, 2 transfer conduit
P3: 3 transfer conduit P4: 4 transfer conduit
S1, S2, S3: 1, 2, 3 Detection unit S11: Primary pressure sensor
S12: Secondary pressure sensor S13: Third pressure sensor
S21: Temperature sensors T1, T2, T3: Drain tube
T1: Primary drainage conduit T2: Secondary drainage conduit
T3: Third drainage conduit

Claims (5)

A supply unit 12 for adjusting the supply amount of the biogas supplied from the outside;
A primary filter unit (13) connected to the supply unit (12) to remove fine particles and moisture from the biogas;
A condensing unit (14) for condensing water contained in the biogas transferred from the primary filter unit (13); And
And a secondary filter unit (15) for removing residual water and fine particles contained in the biogas transferred from the condensing unit (14)
Characterized in that the primary filter unit (13) comprises a gravel filter and the secondary filter unit (15) is a PTFE coated membrane filter. The apparatus for removing moisture of biogas according to claim 1, characterized in that the condensing unit (14) comprises a heat condensing exchanger (24) and a condenser (241) connected to the heat condensing exchanger (24). A cleaning unit (17) connected to exhaust tubes (T1, T2, T3) through which the condensation component of the biogas is discharged for cleaning the primary filter unit (13) or the secondary filter unit (15) Further comprising a moisture removing device for the biogas. The two detection units S2 are provided between the condensing unit 14 and the secondary filter unit 15 and the information detected by the two detection units S2 is transmitted to the control unit 11 And the temperature of the condensing unit (14) is adjusted. The PTFE coated membrane filter according to claim 1, wherein the PTFE coated membrane filter is a membrane filter having glass fibers coated with PTFE on at least one surface thereof, the pores of the PTFE have an average diameter of 10 to 60 탆, a thermal expansion coefficient of 100 To 10 x 10 < " 6 > / K at a temperature of 200 to 200 < 0 > C.

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