CLIMATE CONTROLLED STABLE

Abstract

The invention provides a system comprising a closed stable comprising a stable space for housing ruminants, wherein the system is configured for controlling in a controlling mode a methane concentration in the stable air between a minimal methane concentration C.sub.m−≥500 ppmv and a maximal methane concentration C.sub.m+ selected to be equal to or smaller than the lower explosion limit of methane in the stable air C.sub.mLEL, and wherein the system is configured for controlling in the controlling mode a dinitrogen concentration in the stable air to be smaller than the ambient dinitrogen concentration in ambient air.

Claims

1. A system (10) comprising a closed stable (100) comprising a stable space (110) for housing ruminants, wherein the system (10) is configured for controlling in a controlling mode a methane concentration in the stable air (11a) between a minimal methane concentration C.sub.m−≥500 ppmv and a maximal methane concentration C.sub.m+ selected to be equal to or smaller than the lower explosion limit of methane in the stable air C.sub.mLEL, and wherein the system (10) is configured for controlling in the controlling mode a dinitrogen (N.sub.2) concentration in the stable air (11a) to be smaller than the ambient dinitrogen concentration in ambient air (11b).

2. The system (10) according to claim 1, wherein the minimal methane concentration C.sub.m−≥5000 ppmv, and wherein the maximal methane (CH.sub.4) concentration C.sub.m+≤45,000 ppmv, wherein the system (200) is configured for controlling in a controlling mode a dinitrogen (N.sub.2) concentration in the stable air (11a) to be in a range of 700,000-780,000 ppmv.

3. The system (10) according to claim 1, wherein the system (200) is configured for controlling in a controlling mode the concentration in the stable air (11a) of: methane (CH.sub.4) to be in the range of 45,000 ppmv, dinitrogen (N.sub.2) to be in the range of 700,000-780,000 ppmv, dioxygen (O.sub.2) to be in the range of 180,000-240,000 ppmv, carbon dioxide (CO.sub.2) to be in the range of 20,000 ppmv, ammonia (NH.sub.3) to be in the range of 1,000 ppmv, non-methane volatile organic compounds to be in the range of 0-500 ppmv, and hydrogen sulfide (H.sub.2S) to be in the range of 0-500 ppmv.

4. The system (10) according to claim 1, wherein the system (10) further comprises a methane filter system (220a) comprising a methane filter (221a), wherein the methane filter (221a) is configured for capturing methane (CH.sub.4) from the stable air (11a), fed to the methane filter (221a) and wherein the methane filter system (220a) is configured to provide the captured methane (CH.sub.4) to a methane consumption system (90) and/or to a methane storage system (95), wherein the system (10) further comprises a dinitrogen filter system (220b), wherein the dinitrogen filter system (220b) comprises a dinitrogen filter (221b), wherein the dinitrogen filter (221b) is configured for capturing dinitrogen (N.sub.2) from the stable air (11a) and/or from ambient air (11b) fed to the dinitrogen filter (221b), and wherein the dinitrogen filter system (220b) is configured to provide the captured dinitrogen (N.sub.2) to the ambient air (11b).

5. The system (10) according to claim 1, wherein the system (10) comprises a circulation space (60) in fluid connection to the stable space (110), wherein the circulation space (60) is configured to receive stable air (11a) from the stable space (110) and to provide recirculated air (11d) to the stable space (110), wherein the circulation space (60) is functionally coupled to an air property adjustment device configured such that an air property of the recirculated air (11d) differs from the air property of the stable air (11a), wherein the air property is selected from the group consisting of a temperature, a relative humidity, and an air composition, wherein the air property adjustment device at least comprises a cooling device (250) wherein the system (200) is configured for controlling the cooling device (250) to control a temperature of the stable air (11a) in the range of 0-20° C., and wherein the system (200) is configured for controlling the cooling device (250) such that a temperature difference between the recirculated air (11d) and the stable air (11a) is less than 5° C.

6. The system (10) according to claim 5, wherein the stable (100) comprises a wall (20) and a roof (40) defining the stable space (110), wherein at least part of the wall (20) comprises an inner wall (21) and an outer wall (22), wherein at least part of the circulation space (60) is arranged between the inner wall (21) and the outer wall (22), wherein the inner wall (21) comprises a wall opening (101, 102) configured to provide the fluid connection between the stable space (110) and the circulation space (60), and wherein the cooling device (250) is arranged at the wall opening (101, 102) such that at least part of the air flowing between the stable space (110) and the circulation space (60) passes the cooling device (250).

7. The system (10) according to claim 5, wherein the system (10) comprises a recirculated air supply (64) configured for guiding recirculated air (11d) from the circulation space (60) to the stable space (110), wherein the recirculated air supply (64) comprises an air conduit (65) arranged in the stable space (110), wherein the air conduit comprises perforations (66) configured for distributing the recirculated air (11d) over the stable space (110).

8. The system (10) according to claim 1, wherein the stable (10) further comprises a floor element (50) configured for separating manure (51) and urine (52) deposited at the floor element (50), wherein the floor element (50) comprises a urine duct (53) for guiding urine (52) to a urine collection space, wherein the system (10) further comprises an air extraction system, wherein the air extraction system is configured to extract urine-associated air from one or more of the urine duct (53) and the urine collection space.

9. The system (10) according to claim 4, wherein the system (10) further comprises an airflow device (260) configured for providing one or more of: a methane filter airflow to the methane filter system (220a), wherein the methane filter airflow comprises stable air (11a), a dinitrogen filter airflow to the dinitrogen filter system (220b), wherein the dinitrogen filter airflow comprises stable air (11a) and/or ambient air (11b), a dehumidifying airflow to the dehumidifier (270), wherein the dehumidifying airflow comprises stable air (11a) and/or ambient air (11b), a cooling airflow to the cooling device (250), wherein the cooling airflow comprises stable air (11a) and/or ambient air (11b), a recirculation airflow to and from the circulation space (60), wherein the recirculation airflow respectively comprises stable air (11a) and recirculated air (11d), and an extraction airflow to extract urine-associated air from one or more of the urine duct (53) and the urine collection space, wherein the extraction airflow comprises urine-associated air.

10. The system (10) according to claim 1, wherein the system (10) comprises a dehumidifier (270), wherein the system (200) is configured for controlling the dehumidifier (270) to control a relative humidity of the stable air (11a) in the range of 35-80%.

11. A method for reducing gaseous emissions from livestock keeping, wherein the livestock comprises ruminants, the method comprising: housing the livestock in a stable space (110) of a closed stable (100), wherein the stable space (110) comprises stable air (11a); controlling a methane concentration in the stable air (11a) by capturing methane from the stable air (11a) such that the methane concentration is controlled between a minimal methane concentration C.sub.m−≥500 ppmv and a maximal methane concentration C.sub.m+ selected to be equal to or smaller than the lower explosion limit of methane in the stable air C.sub.mLEL; controlling a dinitrogen concentration in the stable air (11a) by capturing dinitrogen from the stable air (11a) such that the dinitrogen concentration is smaller than the ambient dinitrogen concentration in ambient air (11b); and providing the captured methane to a methane consumption system (90) and/or a methane storage system (95).

12. The method according to claim 11, wherein the minimal methane concentration C.sub.m− is selected equal to or larger than 5000 ppmv, and wherein the maximal methane concentration C.sub.m+ is selected equal to or smaller than 45,000 ppmv, wherein the method further comprises controlling the dinitrogen concentration in the stable air (11a) to be in the range of 700,000-780,000 ppmv.

13. The method according to claim 1, the method comprising controlling in a controlling mode the concentration in the stable air of: methane (CH.sub.4) to be in the range of 500-45,000 ppmv, dinitrogen (N.sub.2) to be in the range of 700,000-780,000 ppmv, dioxygen (O.sub.2) to be in the range of 180,000-240,000 ppmv, carbon dioxide (CO.sub.2) to be in the range of 20,000 ppmv, ammonia (NH.sub.3) to be in the range of 1,000 ppmv, non-methane volatile organic compounds to be in the range of 0-500 ppmv, and hydrogen sulfide (H.sub.2S) to be in the range of 0-500 ppmv.

14. The method according to claim 11, the method comprising providing stable air (11a) from the stable space (110) to a circulation space (60) in fluid connection to the stable space (110) and providing recirculated air (11d) from the circulation space (60) to the stable space (11); and controlling a temperature difference between the recirculated air (11d) and the stable air (11a) to be less than 5° C.

15. The method according to claim 11, the method further comprising (i) separating manure (51) and urine (52) deposited by the livestock at a floor of the closed stable (100), and (ii) extracting urine-associated air from urine (52) and providing the extracted urine-associated air to an ammonia processing system.

16. The method according to claim 11, the method comprising providing the stable air to a cooling device and/or a dehumidifier to control a relative humidity of the stable air (11a) in the range of 35-80%, and/or to control a temperature of the stable air (11a) in the range of 0-20° C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0179] Embodiments of the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, and in which:

[0180] FIG. 1 schematically depicts an embodiment of the system;

[0181] FIG. 2 schematically depicts aspects of the system comprising a circulation space;

[0182] FIG. 3 schematically depicts aspects of the gas filter system;

[0183] FIGS. 4-5 schematically depict aspects of the floor element and the manure scraping system; and

[0184] FIG. 6 schematically depicts some further aspects of the system.

[0185] The schematic drawings are not necessarily on scale.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0186] FIG. 1 schematically depicts a system 10 comprising a closed stable 100 comprising a stable space 110 for housing livestock. During operation, the livestock may provide methane to stable air 11a in the stable space 110. The system 10 further may comprise a control system 200 configured for controlling in a controlling mode a methane concentration in the stable air 11a. The stable 100 comprises a wall 20 and a roof 40 defining the stable space 110 of the closed stable 100. The closed stable 100 may be configured to have substantially limited uncontrolled outflow of stable air 11a to the ambient air lib. The stable space 110 may comprise a volume, wherein an uncontrolled outflow of stable air 11a from the stable space 110 (to the ambient air lib) per hour is less than 2% of the volume. A closed stable 100 may be particularly beneficial with regard to the controlling of an air property (of stable air 11a) at a different value than the (air property of the) ambient air 11b.

[0187] The system 10 comprises an air property adjustment device 240 configured to adjust an air property of the stable air 11a. In further embodiments, the air property adjustment device may comprise a device selected from the group consisting of a temperature control element, a humidity control element, a gas filter system 220, or a pressure control element.

[0188] In further embodiments, the air property adjustment device may be functionally coupled to a control system 200. The control system may be configured to control the air property adjustment device 240. The control system 200 may further be configured to control an air property of stable air 11a.

[0189] In the depicted embodiment, the system 10 comprises a dehumidifier 270. In FIG. 1, the air property adjustment device 240 comprises the dehumidifier 270, wherein the system 10, especially the control system 200, is configured for controlling the dehumidifier 270 to control a relative humidity of the stable air 11a in the range of 20-80%, such as 35-75%, especially 50-70%.

[0190] In the depicted embodiment, the system 10 further comprises or is functionally coupled to a cooling device 250. Especially, the air property adjustment device 240 comprises a cooling device 250, wherein the system 10 is configured for controlling the cooling device 250 to control a temperature of the stable air 11a in the range of −15-(+)25° C., such as 0-20° C., especially 10-15° C., such as 7-14° C. The cooling device 250 and the dehumidifier 270 may be the same device (as depicted in FIG. 1). Especially the cooling device 250 may be functionally coupled to the control system 200, wherein the control system 200 is configured for controlling the cooling device 250 to control a temperature of the stable air 11a in the range of −15-25° C., such as 0-20° C., especially 10-15° C.

[0191] The system 10 may further comprise a sensor system 201 comprising a sensor 210 configured for sensing a parameter related to an air property of air, especially stable air 11a, and for providing a signal to an air property adjustment device 240 and/or to the control system 200.

[0192] In embodiments, the stable 10 further comprises a floor element 50 configured for separating of manure 51 and urine 52 deposited at the floor element 50.

[0193] In embodiments, at least part of the wall 20 is configured to transmit at least part of ambient light into the stable space 110.

[0194] FIG. 2 schematically depicts embodiments of the system 10 comprising a circulation space 60. For visualization purposes only, only part of the system is depicted. The circulation space 60 is in fluid connection to the stable space 110. The circulation space 60 may be configured to receive stable air 11a from the stable space 110 and to provide recirculated air 11d to the stable space 110. The circulation space 60 may be functionally coupled to an air property adjustment device 240 configured such that an air property of the recirculated air 11d differs from the air property of the stable air 11a. The air property may be selected from the group consisting of a temperature, a relative humidity, an air composition, and pressure. In the depicted embodiment, the stable 100 comprises a wall 20 and a roof 40 defining the stable space 110. At least part of the wall 20 comprises an inner wall 20,21 and an outer wall 20,22. At least part of the circulation space 60 is arranged between the inner wall 21 and the outer wall 22. The inner wall 21 comprises a wall opening 101, 102 configured to provide the fluid connection between the stable space 110 and the circulation space 60.

[0195] The wall opening 101,102 may comprise two or more openings, such as two openings. Hence, the circulation space 60 may provide a flow channel connecting a first wall opening 101 of the wall opening 101, 102 to a second wall opening 102 of the wall opening 101, 102. The flow channel may especially be configured to feed air to the air adjustment device 240. Especially, stable air 11a may be provided to the circulation space 60 through the first wall opening 101, and recirculated air lid may be provided to the stable space 110 through the second wall opening 102.

[0196] In the depicted embodiment, the air property adjustment device 240 is arranged at the wall opening 101, 102, especially at the first wall opening 101, such that at least part of the air, especially substantially all of the air, flowing between the stable space 110 and the circulation space 60 passes the air property adjustment device 240.

[0197] In embodiments, the air property adjustment device 240 may comprise one or more of a gas filter system 220, especially the methane filter system 220a, and/or the dinitrogen filter system 220b; a humidity control element, especially a dehumidifier 270; and a temperature control element, especially a cooling device 250. In the depicted embodiment, the air property adjustment device comprises the cooling device 250. The cooling device 250 is arranged at the first wall opening 101 (but may also be arranged at the second wall opening 102) such that at least part of the air flowing between the stable space 110 and the circulation space 60 passes the cooling device 250.

[0198] In further embodiments, the system 10, especially the control system 200, is configured for controlling the cooling device 250 such that a temperature difference between the recirculated air 11d and the stable air 11a is less than 5° C., such as less than 4° C., especially less than 3° C. Hence, in embodiments, the method may comprise controlling a temperature difference between the recirculated air and the stable air to be less than 5° C., such as less than 4° C., especially less than 3° C.

[0199] In yet further embodiments, the system 10 comprises a recirculated air supply 64 configured for guiding recirculated air lid from the circulation space 60 to the stable space 110. The recirculated air supply 64 comprises an air conduit 65 arranged in the stable space 110. The air conduit may comprise perforations 66 configured for distributing the recirculated air lid over the stable space HO. Hence, the circulation space may be configured to provide recirculated air lid to the stable space 110 via the recirculated air supply 64. In specific embodiments, the air conduit 65 is arranged at the roof 40, especially attached to the roof 40. The recirculated air supply may especially be in fluid connection to the second wall opening 102.

[0200] In the depicted embodiment, the stable air 11a is withdrawn from the stable space 110 through the first wall opening 101, and recirculated air lid is provided through the second wall opening 102, wherein the first wall opening 101 is lower than the second wall opening 102. The first wall opening 101 may be configured close to the floor, such as configured at a distance ≤1 m to the floor, especially at a distance of ≤0.5 m. The second wall opening 102 may be configured close to the roof 40, such as configured at a distance ≤1 m to the (inner) roof, especially at a distance of ≤0.5 m.

[0201] In the depicted embodiment, the system 10 further comprises an airflow device 260. The airflow device 260 is (at least partially) arranged in the circulation space 60. The airflow device is configured for providing a recirculation airflow to and from the circulation space 60, wherein the recirculation airflow respectively comprises stable air 11a and recirculated air lid. In further embodiments, the airflow device 260 may further be configured for providing one or more of a methane filter airflow to a methane filter system 220a, wherein the methane filter airflow comprises stable air 11a, a dinitrogen filter airflow to a dinitrogen filter system 220b, wherein the dinitrogen filter airflow comprises stable air 11a and/or ambient air 11b, a dehumidifying airflow to a dehumidifier 270, wherein the dehumidifying airflow comprises stable air 11a and/or ambient air 11b, a cooling airflow to a cooling device 250, wherein the cooling airflow comprises stable air 11a and/or ambient air 11b, and an extraction airflow to extract urine-associated air from one or more of a urine duct 53 and a urine collection space, wherein the extraction airflow comprises urine-associated air.

[0202] Hence, in embodiments, the wall 20 of the stable 100 consists of two walls 20 that are separated by a space of, for example, approximately 1 meter. The outer wall 20,22 may be fully closed. In further embodiments at least part of the outer wall 20,22 may be transparent. Especially, the outer wall 20,22 may be transparent. The inner wall 20,21 may be partially closed. In further embodiments, at least part of the inner wall 20,21 may be transparent. Especially, the inner wall 20,21 may be transparent. Between the inner wall 20,21 and the outer wall 20,22, especially in the circulation space 60, the air pressure may be slightly lower than in the stable 100, providing stable air 11a from the stable space 110 to the circulation space 60 through the cooling device 250, especially through a cooling pad. In the depicted embodiment, the cooling device 250 is located at the bottom of the inner wall 20,21 at first wall opening 101 through which stable air 11a flows from the stable space 110 into the circulation space 60, and is configured to cool and dehumidify the air flowing through.

[0203] In further embodiments, the air in the circulation space 60 may be brought to an upper pressure chamber between the walls via an airflow device 260, such as a ventilator. The air may be recirculated into the stable space 110 from the upper pressure chamber via an air conduit 65, wherein the air conduit 65 may comprise perforations 66 configured to distribute the recirculated air lid over the stable space 110.

[0204] FIG. 3 schematically depicts an embodiment of the system 10 comprising or functionally coupled to a gas filter system 220. The gas filter system 220 comprises a gas filter 221 configured for capturing a gaseous compound from the air fed to the gas filter 221. In embodiments, the air fed to the gas filter system 221 may comprise stable air 11a. In further embodiments, the air fed to the gas filter 221 may comprise ambient air 11b. The gas filter system 220 may be configured to provide the filtered air 11c to the stable air 11a and/or to the ambient air 11b. The gas filter system 220 may be functionally coupled to the control system 200, i.e., the control system 200 may be configured to control the gas filter system 220, especially to control an air property of the stable air 11a. The control system may further be functionally coupled to a sensor system 201 comprising a sensor 210 configured to sense an air property of (stable) air. The sensor 210 may especially be arranged in the stable space 110.

[0205] In embodiments wherein the circulation space 60 comprises the gas filter system 220, the recirculated air lid and the filtered air 11c may be the same air, especially the recirculated air lid may comprise the filtered air 11c.

[0206] In the depicted embodiment, the system 10 comprises both a methane filter system 220, 220a and a nitrogen filter system 220, 220b.

[0207] The methane filter system 220a comprises a methane filter 221a configured for capturing methane from the air fed to the methane filter 221a. In the depicted embodiment, only stable air 11a is fed to the methane filter 221a. The methane filter system 220a is configured to provide the captured methane to a methane consumption system 90 and/or to a methane storage system 95. In specific embodiments, the methane filter system 220a is configured to provide the captured methane to the methane consumption system 90, wherein the methane consumption system 90 comprises one or more of a combined heat power system, an algae production unit, and a liquefied natural gas production system. The methane filter system is further configured to provide filtered air 11c to the stable air 11a and/or to the ambient air lib. In further embodiments, the system 10, especially the control system 200, is configured for controlling (in a controlling mode) the methane concentration in the stable air 11a between a minimal methane concentration C.sub.m− and a maximal methane concentration C.sub.m+, wherein C.sub.m−≥500 ppmv, and wherein C.sub.m+≤45,000 ppmv. Especially, the system 10 may control the methane concentration in the stable air 11a by controlling the gas filter system 220, especially the methane filter system 220a or the nitrogen filter system 220b, or by controlling an airflow of air to the gas filter system 220. In yet further embodiments, C.sub.m−≥5000 ppmv, and C.sub.m+≤45,000 ppmv.

[0208] The dinitrogen filter system 220b comprises a dinitrogen filter 221b configured for capturing dinitrogen from the stable air 11a and/or from ambient air lib fed to the dinitrogen filter 221b. The dinitrogen filter system 220b is configured to provide the filtered air 11c to the stable air 11a. The dinitrogen filter system 220b is configured to provide the captured dinitrogen to the ambient air lib. In further embodiments, the system 10, especially the control system 200, is configured for controlling in a controlling mode a dinitrogen concentration in the stable air 11a to be in a range of 700,000-780,000 ppmv.

[0209] In further embodiments, the gas filter system 220 comprises a swing adsorption system, especially a pressure swing adsorption system. Especially, the methane filter system 220a comprises a methane pressure swing adsorption system.

[0210] In further embodiments, the system 10, especially the control system 200, is configured for controlling in a controlling mode the concentration of: methane (CH.sub.4) to be in the range of 0-45,000 ppmv, dinitrogen (N.sub.2) to be in the range of 700,000-780,000 ppmv, dioxygen (O.sub.2) to be in the range of 180,000-240,000 ppmv, carbon dioxide (CO.sub.2) to be in the range of 0-20,000 ppmv, ammonia (ME) to be in the range of 0-1,000 ppmv, non-methane volatile organic compounds (NMVOC) to be in the range of 0-500 ppmv, and hydrogen sulfide (H.sub.2S) to be in the range of 0-500 ppmv. In such embodiments, the system 10, especially the control system 200, may comprise or be functionally coupled to a gas filter system 220 comprising a gas filter 221 configured to capture one or more of CH.sub.4, N.sub.2, O.sub.2, CO.sub.2, Mb, NMVOC, and H.sub.2S, especially one or more of N.sub.2, O.sub.2, CO.sub.2, NH.sub.3, NMVOC, and H.sub.2S.

[0211] FIGS. 4 and 5 schematically depict aspects of the floor element 50 (in a stable 100). The floor element 50 comprises a urine duct 53 for guiding urine 52 to a urine collection space (in the stable) (not depicted in the figures). The floor element 50, further comprises a manure scraping system 55 comprising a manure scraper 56 arranged at the floor element 50 and configured for providing manure 51 from the floor element 50 to a manure collection space 54 (in the stable 100). The floor element 50 comprises a floor arranged at a slope at an angle α (relative to horizontal plane N), wherein the floor slopes down to a urine duct 53. In embodiments, the angle α may be selected from the range of 0.5-5°, such as from the range of 1.5-4°, such as 2-3°.

[0212] In the embodiment of FIG. 4, the urine duct 53 is arranged centrally on the floor element 50. The floor element 50 is arranged such that the urine duct is arranged at a lowest point of a slope (at an angle α) of the floor element. The slope is selected such that urine 52 substantially flows towards the urine duct 53, whereas the more viscous manure 51 does not substantially flow towards the urine duct 53. Rather, the manure scraper 56 is configured to provide manure 51 from the floor element 50, especially from the floor, to the manure collection space 54. In the depicted embodiment, the manure collection space 54 comprises transport tubing configured to receive the manure and to provide the manure 51 to a further part of the manure collection space 54.

[0213] In further embodiments, the urine duct 53 is configured for the extraction of urine-associated air. Especially, the system may comprise an air extraction system, wherein the air extraction system is configured to extract urine-associated air from the urine duct 53. In yet further embodiments, the air extraction system may be configured to extract urine-associated air from the urine collection space. In yet further embodiments, the air extraction system may be configured to provide the extracted urine-associated air to an ammonia processing system. Hence, in embodiments, the method may comprise extracting urine-associated air from urine, and especially providing the extracted urine-associated air to an ammonia processing system.

[0214] FIG. 5 depicts an embodiment of the manure scraping system 55 and the manure scraper 56. The manure scraper 56 has a shape resembling the letter W. The manure scraper 56 comprises a central part configured to scrape manure 51 out of the urine duct 53. The W-shape may be beneficial as it both (i) reduces (minimizes) the amount of manure 51 pushed to the side (relative to an -shape, or a {circumflex over ( )}-shape), and (ii) reduces (minimizes) the amount of manure 51 pushed over/in the urine duct 53 (relative to a V-shape). In the depicted embodiment, the floor element 50 further comprises a lid element 58 configured to substantially block fluid contact between the manure collection space 54 and the stable space 110. Hence, the manure scraper 56 further comprises a manure scraper ramp 57 configured to move below the lid element 58, thereby lifting the lid element 58. By lifting the lid element 58, the manure scraper 56 can push the manure 51 into the manure collection space 54.

[0215] FIG. 6 schematically depicts an embodiment of the system 10 and the circulation of air in the stable space 110. In the embodiment, the system comprises a plurality of air property adjustment devices 240. At least one of the air property adjustment devices 240 comprises a cooling device 250 and dehumidifier 270, especially a cooling device 250 configured to also reduce the relative humidity. At least one other one of the air property adjustment devices 240 comprises a methane gas filter system 220,220a. The stable air 11a circulates through the stable space 110. The livestock, depicted as cattle, may continuously produce CH.sub.4, CO.sub.2, heat and water vapor that will increase the temperature and relative humidity inside the stable 100. Regardless, in the depicted embodiment, the system 10, especially the control system 200, may be configured to provide a constant temperature and relative humidity in the stable 100. The cooling device 250 cools and dehumidifies the stable air 11a. In the embodiment, the stable 100 may be fully closed to accomplish this constant climate. The methane gas filter system 220a captures CH.sub.4 from the stable air 11a and provides the captured CH.sub.4 to a methane consumption system 90. In the depicted embodiment, the methane consumption system 90 is configured to receive a second feed 92. The second feed may comprise, for example, biogas (from a biogas production unit) and/or NH.sub.3-enriched air (from the air extraction system and/or from an ammonia processing system). The methane consumption system may provide a methane consumption output, such as CO.sub.2 (provided to ambient air 11b), electricity (to power the system), heat (to provide heating of the stable and/or hygienization of manure), biogas, PHB, algae biomass, and other products.

[0216] Hence, FIG. 6 further illustrates a method for reducing methane emissions from livestock, the method comprising: housing the livestock in a stable space 110 of a closed stable 100, especially wherein the livestock provide methane to stable air 11a in the stable space (110); controlling a methane concentration in the stable air 11a by capturing the methane from the stable air 11a (using a methane filter system 220a) such that the methane concentration (in the stable air 11a) is between a minimal methane concentration C.sub.m− and a maximal methane concentration C.sub.m+, wherein C.sub.m−≥500 ppmv, and wherein C.sub.m+<45,000 ppmv; providing the captured methane to a methane consumption system 90 and/or a methane storage system 95, especially to a methane consumption system 90 in the depicted embodiment. Herein, a number of thousand may be indicated by a dot separating the number and three zeros. Hence 1,000, 2,000 and the like especially refers to one thousand, two thousand (also written as 1,000 and 2,000 or 1000 and 2000) etc.

[0217] The term “plurality” refers to two or more.

[0218] The terms “substantially” or “essentially” herein, and similar terms, will be understood by the person skilled in the art. The terms “substantially” or “essentially” may also include embodiments with “entirely”, “completely”, “all”, etc. Hence, in embodiments the adjective substantially or essentially may also be removed. Where applicable, the term “substantially” or the term “essentially” may also relate to 90% or higher, such as 95% or higher, especially 99% or higher, even more especially 99.5% or higher, including 100%.

[0219] The term “comprise” includes also embodiments wherein the term “comprises” means “consists of”. The term “and/or” especially relates to one or more of the items mentioned before and after “and/or”. For instance, a phrase “item 1 and/or item 2” and similar phrases may relate to one or more of item 1 and item 2. The term “comprising” may in embodiments refer to “consisting of” but may in another embodiment also refer to “containing at least the defined species and optionally one or more other species”.

[0220] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. The term “further embodiment” may refer to embodiments comprising the features of the previously discussed embodiment, but may also refer to an alternative embodiment.

[0221] The devices, apparatus, or systems may herein amongst others be described during operation. As will be clear to the person skilled in the art, the invention is not limited to methods of operation, or devices, apparatus, or systems in operation. The term “controls” and similar terms herein especially relates to a device, apparatus, or system during operation, especially during a controlling mode. Hence, a phrase such as “configured for controlling” especially refers to “configured for controlling in a controlling mode”. The device, apparatus, or system may also be operated in a non-controlling mode. The device, apparatus, or system may further be operated in two or more different controlling modes, especially wherein the controlling modes are temporally separated.

[0222] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims.

[0223] In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “to comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.

[0224] The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In a device claim, or an apparatus claim, or a system claim, enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

[0225] The invention also provides a control system that may control the device, apparatus, or system, or that may execute the herein described method or process. Yet further, the invention also provides a computer program product, when running on a computer which is functionally coupled to or comprised by the device, apparatus, or system, controls one or more controllable elements of such device, apparatus, or system.

[0226] The invention further applies to a device, apparatus, or system comprising one or more of the characterizing features described in the description and/or shown in the attached drawings. The invention further pertains to a method or process comprising one or more of the characterizing features described in the description and/or shown in the attached drawings.

[0227] The various aspects discussed in this patent can be combined in order to provide additional advantages. Further, the person skilled in the art will understand that embodiments can be combined, and that also more than two embodiments can be combined. Furthermore, some of the features can form the basis for one or more divisional applications.

Effects of the Measures

[0228] For a dairy farm having incorporated measures described herein and a standard dairy farm, emissions have been calculated and compared. The conditions of the two systems are given below:

TABLE-US-00001 embodiment of a farm Standard according to dairy farm the invention difference Number of dairy cows 100 100 — Total area (hectare) 47 42 5.32 of which grass land, and 37.8 17.7 20.13 silage maize 9.4 24.2 −14.82 Production milk (kg/cow) 8500 14000 −5500 [0229] (i) The area for the production of silage maize in the embodiment of a farm of the invention corresponds to the required total amount of roughage per cow (no further roughage has to be purchased externally, only feed concentrates are purchased, (ii) The production per cow of 14000 kg milk is calculated based on the higher productivity resulting from the excess of energy per cow, which energy normally is required for cooling. The energy may now be used for milk production, without applying additional feed, (ii) The embodiment of the farm of the invention comprises an embodiment of the floor element described herein and a methane consumption system comprising a combined heat power system coupled to a hygienization system.

[0230] Based on these conditions, the emissions are compared, see next table. In the table the energy use is directly depicted in kg CO.sub.2 emitted, and the emissions of the other greenhouse gases (GHG) N.sub.2O and CH.sub.4 are given in kgs of the respective compound as well as in equivalent kgs CO.sub.2.

TABLE-US-00002 embodiment standard of Emission/use farm the invention difference Emission 10.70 5.46      5.24.sup.1 N.sub.2O (kg N.sub.2O) in (kg CO.sub.2) 150,502 68,202  82,300 Emission of 435.90 15.30     420.60.sup.2 CH.sub.4 (kg CH.sub.4) in (kg CO.sub.2) 576,085 17,943 558,143 Energy use/emission of 234,125 91,919 142,206 CO.sub.2 (kg CO.sub.2) Total emission GHG (kg CO.sub.2) Per farm 960,712 178,063 782,649 Per cow 9,607 1,781  7,826 Per kg milk 1.13 0.13     1.00 Emission 1818 143   .sup. 1675.sup.3 NH.sub.3 (kg NH.sub.3 ) .sup.1In which about 65% is the result of housing the cows in the closed stable as such; .sup.2In which about 77% is the result of capturing CH4. .sup.3In which about 5% is the result of housing the cows in the closed stable as such.