Device for producing biogas with high methane content by utilizing livestock and poultry feces

Abstract

The invention discloses a device for producing biogas with high methane content by utilizing livestock and poultry feces, wherein the interior of a tank body of a biogas fermentation tank is divided by a baffle, so as to form a main reaction chamber and an auxiliary reaction chamber which are communicated in upper portions, so that a reactant flows into the auxiliary reaction chamber only after entering the main reaction chamber via a relatively low feeding hole and then reaching a high position of a liquid level, and extension of fermentation time is realized, meanwhile, scales formed at the top of fermentation broth flow into the auxiliary reaction chamber along with liquid, so that the interior of the main reaction chamber keeps a liquid state all the time, and sealing and reduction of quantity of anaerobic bacteria are avoided.

Claims

1. A device for producing biogas with high methane content by utilizing livestock and poultry feces, comprising: a feces collecting pond used for collecting livestock and poultry feces in a unified mode, the feces collecting pond being internally provided with grids for filtering feces, an acidifying pond connected with the feces collecting pond by a pipeline and used for acidifying livestock and poultry feces, the acidifying pond being internally provided with an agitator, and being externally provided with an automatic doser, a biogas fermentor connected with the acidifying pond by a pipeline and used for fermenting livestock and poultry feces to produce biogas, the biogas fermentor comprising a tank body, an insulating layer provided on an outer side of the tank body, a heating device buried in the insulating layer, an agitator provided at the lower half portion of the tank body, and a clapboard provided at the upper portion of the tank body and dividing an internal space of the tank body into a main chamber and an auxiliary chamber; the heating device being a warming pipe specifically; upper portions of the auxiliary chamber and the main chamber being in a communicated state and meanwhile lower portions being separated by the clapboard; a biogas residue outlet A being formed in the bottom of the auxiliary chamber, and a biogas slurry outlet being formed in a side wall of the auxiliary chamber; the agitator being capable of agitating reactants in the main chamber intensively when being started; a feeding hole being formed in the other side, opposite to the agitating device, of the tank body, and a biogas opening and a biogas residue outlet B being respectively formed in the top and the bottom of the tank body, a biogas purifier connected with the biogas opening by a pipeline and used for removing oil, dust and particle impurities in biogas, a biogas refiner connected with the biogas purifier by a pipeline and used for refining biogas, the biogas refiner comprising at least one biogas membrane treatment device, the biogas membrane treatment device comprising a hollow fibrous membrane in the shape of a wavy line; a biogas inlet, a biogas outlet and an impurity gas outlet being respectively formed in the bottom, the top and the side face of the biogas membrane treatment device, a biogas compressor connected with a gas outlet of the biogas refining device and used for compressing biogas, and a biogas storage tank connected with the biogas compressor and used for storing biogas, each of the above-mentioned pipelines being provided with a power supply and a valve for conveying a target object from a last structure to a next structure.

2. The device for producing biogas with high methane content by utilizing livestock and poultry feces according to claim 1, wherein the agitator is in a horizontal state, and comprises a frame agitator, an inside agitator provided in the frame agitator, a main motor used for driving the frame agitator, a shaft motor used for driving the inside agitator and a gear motor, the inside agitator being one of the followings: an inclined-blade dual-blade agitator, a straight-blade turbine agitator, and a six-inclined-blade disk turbo agitator.

3. The device for producing biogas with high methane content by utilizing livestock and poultry feces according to claim 1, wherein the clapboard at least comprises one section of inclined plate, an included angle between the inclined plate and the horizontal plane being 30-60° or 120-150°, and a super-hydrophobic coating being provided on the surface of the inclined plate.

4. The device for producing biogas with high methane content by utilizing livestock and poultry feces according to claim 1, wherein a second biogas compressor is further provided on a pipeline for connecting the biogas purifying device to the biogas opening, the biogas purifying device comprising an oil removal tank, a water removal tank and a particle filtering tank which are connected end to end in sequence.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic structure diagram of embodiment 2 of the invention;

(2) FIG. 2 is a structure diagram of an agitating device of the invention;

(3) FIG. 3 is a process flow diagram of embodiment 1 of the invention; and

(4) FIG. 4 is a process flow diagram of embodiment 2 of the invention.

(5) In the drawings, 1-feces collecting pond, 11-grids; 2-acidifying pond, 21-agitator, 22-automatic doser or dosing device; 3-biogas fermenting pond, 31-tank body, 311-main chamber, 312-auxiliary chamber, 3121-biogas residue outlet A, 3122-biogas slurry outlet, 32-insulating layer, 33-heating device, 34-agitating device, 341-main motor, 342-gear motor, 343-shaft motor, 344-frame agitator, 345-inside agitator, 35-clapboard, 351-inclined plate, 36-feeding hole, 37-biogas opening, 38-biogas residue outlet B; 4-biogas purifying device, 41-oil removal tank, 42-water removal tank, 43-particle filtering tank; 5-biogas refining device, 51-biogas membrane treatment device, 511-biogas inlet, 512-biogas outlet, 513-impurity gas outlet; 6-settling pond, 61-biogas residue outlet C; 7-MBR treating pond, 71-MBR plate type membrane; 8-sludge thickener, 81-main body, 82-sludge inlet, 83-water outlet, 84-sludge outlet; 9-biogas compressor; 10-biogas storage tank.

DESCRIPTION OF THE EMBODIMENTS

(6) The following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some of the embodiments of the present invention rather than all of the embodiments. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present disclosure.

Embodiment 1

(7) Engineering environment: a large-scale chicken farm, with daily feces production of 4.32 tons, near to a fruit tree culture area.

(8) A device for producing biogas with high methane content by utilizing livestock and poultry feces is designed aiming at the environment, as shown in FIG. 3, comprising a feces collecting pond 1, an acidifying pond 2, a biogas fermentor 3, a biogas purifying device 4, a biogas refining device 5, a biogas compressor 9 and a biogas storage tank 10, because internal utilization of biogas slurry and biogas residue may be realized in the present embodiment, additional arrangement of a treatment device is not needed;

(9) Pretreatment Unit

(10) feces collecting pond 1: design volume 24 m.sup.3;

(11) the feces collecting pond 1 is used for collecting livestock and poultry feces in a unified mode, a collecting pipeline is provided in the bottom of a livestock and poultry captive breeding area, so that feces of livestock and poultry and flushing sewage are automatically collected to the feces collecting pond 1 via inclined pipelines, grids 11 are provided in the feces collecting pond 1 and used for intercepting large-size wastes, so as to prevent blockage of pipelines in a transportation process;

(12) acidifying pond 2: design volume 6.6 m.sup.3;

(13) the acidifying pond 2 is used for acidifying macrofibers in livestock and poultry feces to be simple organic matters to be convenient for subsequent anaerobic bacteria treatment, the acidifying pond 2 is internally provided with a propelling type agitator 21, and externally provided with an automatic doser or dosing device 22, meanwhile, the acidifying pond 2 regulates feces to a proper viscosity to enter subsequent fermentation;

(14) Fermenting Unit

(15) an improved CSTR reactor is adopted as a biogas fermentor 3: design volume 125 m.sup.3;

(16) the biogas fermentor 3 is used for fermenting organic matters in feces by utilizing anaerobic bacteria so as to obtain biogas; a specific structure includes a tank body 31, an insulating layer 32, a heating device 33, an agitating device 34 and a clapboard 35, wherein the insulating layer 32 is provided on the outer side of the tank body 31;

(17) in a fermentation process, in order to cause anaerobic bacteria to reach a suitable working environment, the temperature needs to be kept at 35-58 DEG C, meanwhile, a certain amount of heat release occurs in a fermentation process, therefore, temperature control may be divided into two aspects of heat preservation and heating, in order to save overall cost and space, the invention adopts a design of integration of a warming pipe and an insulating layer, the heating device 33 includes a warming pipe buried in the insulating layer 32 and realizes heating for the tank body 31 via the warming pipe, here, a specific warming principle of the heating pipe may be aqueous medium warming;

(18) The biggest disadvantage of CSTR is that some hard-to-decompose matters may form floating shells, finally resulting in reduction of fermentation efficiency, finally resulting in reduction of fermentation efficiency, and therefore, according to the invention, functional partition is performed on an internal space of a tank body 31 by utilizing a clapboard 35 to avoid the problem, the clapboard 35 is provided on an upper portion of the tank body 31 and divides the internal space of the tank body 31 into a main chamber 311 and an auxiliary chamber 312, upper portions of the auxiliary chamber 312 and the main chamber 311 are in a communicated state and meanwhile lower portions are separated by the clapboard 35, the space of the main chamber 311 is relatively large, is a main occurrence site of a fermentation process, and has some similarities with a CSTR internal structure of the prior art, while the auxiliary chamber 312 is a main improved point and communicates with the top of the main chamber 312, and liquid in the main chamber 311 will overflow into the auxiliary chamber 312 when reaching a certain height, so as to avoid accumulation of scales and increase reaction time of reactants; a biogas residue outlet A 3121 is formed in the bottom of the auxiliary chamber 312 and used for discharging biogas residue in regular time, a biogas slurry outlet 3122 is formed in a side wall of the auxiliary chamber 312 and used for leading out fermented biogas slurry; the agitating device 34 is provided at a lower portion of the tank body 31, and is capable of agitating reactants in the main chamber 311 intensively when being started, so as to realize mixing of anaerobic bacteria with reactants;

(19) treatment capacity of the tank body in the present embodiment is relatively small, and a commercially available frame agitator may be adopted as the agitating device 34.

(20) A feeding hole 36 is formed in the other side, opposite to the agitating device 34, of the tank body 31, with such design, reactants are agitated intensively as long as entering the tank body, and are gradually removed along with elevation of a liquid level, so that reactants ferment sufficiently, and a disadvantage in the prior art that reactants flow out therewith after flowing into the tank body is avoided, and a biogas opening 37 and a biogas residue outlet B 38 are respectively formed in the top and the bottom of the tank body and are respectively used for conveying biogas and biogas residue;

(21) wherein biogas enters a subsequent treatment unit, biogas residue is applied to the farmland as a solid organic fertilizer, and biogas slurry may be applied to a farmland or an orchard.

(22) Biogas Purifying Unit

(23) oil removal tank 41: model number MJQF DN 25-DN1000

(24) used for removing dust in biogas;

(25) water removal tank 42: model number MQF DN25-DN1000

(26) used for removing dust in biogas;

(27) particle filtering tank 43: model number Environtec G

(28) used for removing particles in biogas;

(29) Biogas Refining Unit

(30) biogas refining device 5: the biogas refining device 5 includes two biogas membrane treatment devices 51, material of the biogas membrane treatment devices 51 is macromolecule polyimide, which is long in service life, compact in structure and safe to use, and separation efficiency reaches up to 95%; a biogas inlet 511, a biogas outlet 512 and an impurity gas outlet 513 are respectively formed in the bottom, the top and the side face each of the biogas membrane treatment devices 51;

(31) commercially available polyimide membrane separators of UBE company are adopted as the biogas membrane treatment devices 51; purified biogas still has a high content of carbon dioxide and may reach the quality of natural gas after being further refined, so that combustion efficiency is increased and combustion pollutants are reduced, meanwhile, H2O, H2S, CO2, CO and the like are removed, biogas with high methane content is produced, and functional efficiency is obviously increased in subsequent application.

(32) Biogas Storage Unit

(33) Biogas compressor 9: model number VW-3/30

(34) used for pressurizing biogas for storage;

(35) biogas storage tank 10: design volume 42 m.sup.3;

(36) used for storing biogas to be distributed to surrounding residents for use.

(37) According to the engineering theory, daily feces treatment capacity is 5.6 t, daily biogas production capacity is 120 m.sup.3, daily biogas residue production capacity is 0.0125 t, biogas slurry production capacity is 3.256 t, and the methane content of the produced biogas reaches up to 67-72%, which is close to the quality of natural gas.

Embodiment 2

(38) Engineering environment: a large-scale livestock farm, with daily feces production of 7.32 tons, near to a farm.

(39) A device for producing biogas with high methane content by utilizing livestock and poultry feces is designed aiming at the environment, as shown in FIG. 3, comprising a feces collecting pond 1, an acidifying pond 2, a biogas fermentor 3, a biogas purifying device 4, a biogas refining device 5, a biogas compressor 9 and a biogas storage tank 10, because internal utilization of biogas slurry and biogas residue may be realized in the present embodiment, additional arrangement of a treatment device is not needed;

(40) Pretreatment Unit

(41) feces collecting pond 1: design volume 24 m.sup.3;

(42) the feces collecting pond 1 is used for collecting livestock and poultry feces in a unified mode, a collecting pipeline is provided in the bottom of a livestock and poultry captive breeding area, so that feces of livestock and poultry and flushing sewage are automatically collected to the feces collecting pond 1 via inclined pipelines, grids 11 are provided in the feces collecting pond 1 and used for intercepting large-size wastes, so as to prevent blockage of pipelines in a transportation process;

(43) acidifying pond 2: design volume 4.3 m.sup.3;

(44) the acidifying pond 2 is used for acidifying macrofibers in livestock and poultry feces to be simple organic matters to be convenient for subsequent anaerobic bacteria treatment, the acidifying pond 2 is internally provided with a propelling type agitator 21, and externally provided with an automatic doser or dosing device 22, meanwhile, the acidifying pond 2 regulates feces to a proper viscosity to enter subsequent fermentation;

(45) Fermenting Unit

(46) an improved CSTR reactor is adopted as a biogas fermentor 3: design volume 186 m.sup.3;

(47) the structure of the biogas fermentor 3 of the present embodiment is basically the same as that of the biogas fermentor in embodiment 1, however, because the viscosity of feces of the present embodiment is relatively high, an inclined section 351 is designed for the clapboard 35, and an included angle between the inclined section 351 and the horizontal plane is 145°, so as to prevent feces from adhering to the wall.

(48) Biogas Purifying Unit

(49) Similar to embodiment 1.

(50) Biogas Refining Unit

(51) Similar to embodiment 1.

(52) Biogas Storage Unit

(53) Biogas compressor 9: model number VW-3/30

(54) used for pressurizing biogas for storage;

(55) biogas storage tank 10: design volume 40 m.sup.3;

(56) used for storing biogas to be distributed to surrounding residents for use.

(57) According to the engineering theory, daily feces treatment capacity is 9 t, daily biogas production capacity is 100 m.sup.3, daily biogas residue production capacity is 0.062 t, biogas slurry production capacity is 5.65 t, and the methane content of the produced biogas reaches up to 67-72%, which is close to the quality of natural gas.

Embodiment 3

(58) Engineering environment: a large-scale breeding-planting comprehensive agricultural and grazing garden, with daily feces production of 12.32 tons.

(59) A device for producing biogas with high methane content by utilizing livestock and poultry feces is designed aiming at the environment, as shown in FIG. 3, comprising a feces collecting pond 1, an acidifying pond 2, a biogas fermentor 3, a biogas purifying device 4, a biogas refining device 5, a biogas compressor 9 and a biogas storage tank 10, because internal utilization of biogas slurry and biogas residue may be realized in the present embodiment, additional arrangement of a treatment device is not needed;

(60) Pretreatment Unit

(61) feces collecting pond 1: design volume 42 m.sup.3;

(62) the feces collecting pond 1 is used for collecting livestock and poultry feces in a unified mode, a collecting pipeline is provided in the bottom of a livestock and poultry captive breeding area, so that feces of livestock and poultry and flushing sewage are automatically collected to the feces collecting pond 1 via inclined pipelines, grids 11 are provided in the feces collecting pond 1 and used for intercepting large-size wastes, so as to prevent blockage of pipelines in a transportation process;

(63) acidifying pond 2: design volume 18.7 m.sup.3;

(64) the acidifying pond 2 is used for acidifying macrofibers in livestock and poultry feces to be simple organic matters to be convenient for subsequent anaerobic bacteria treatment, the acidifying pond 2 is internally provided with a propelling type agitator 21, and externally provided with an automatic doser or dosing device 22, meanwhile, the acidifying pond 2 regulates feces to a proper viscosity to enter subsequent fermentation;

(65) Fermenting Unit

(66) an improved CSTR reactor is adopted as a biogas fermentor 3: design volume 368 m.sup.3;

(67) the composition and structure of the biogas fermentor 3 of the present embodiment are basically the same as those of the biogas fermentor in embodiment 2, however, because the feces amount needing to be treated in the present embodiment is large, a combined agitating device is adopted, the whole combined agitating device is formed by combination of a frame agitator and an inclined-blade dual-blade agitator, the whole device is in a horizontal state, and includes a main motor 341, a gear motor 342, a shaft motor 343, a frame agitator 344 and an inside agitator 345, the inside agitator 345 is provided in the frame agitator 344, and the main motor 341 and the shaft motor 343 are respectively used for driving the frame agitator 344 and the inside agitator 345.

(68) Biogas Purifying Unit

(69) Similar to embodiment 1.

(70) Biogas Refining Unit

(71) Similar to embodiment 1.

(72) Biogas Storage Unit

(73) Biogas compressor 9: model number VW-3/30

(74) used for pressurizing biogas for storage;

(75) biogas storage tank 10: design volume 120 m.sup.3;

(76) used for storing biogas to be distributed to surrounding residents and livestock farms to be used for supplying water and power.

(77) According to the engineering theory, daily feces treatment capacity is 15 t, daily biogas production capacity is 160 m.sup.3, daily biogas residue production capacity is 0.075 t, biogas slurry production capacity is 8.39 t, and the methane content of the produced biogas reaches up to 70-74%, which is close to the quality of natural gas.

Embodiment 4

(78) Engineering environment: a hybrid agricultural base, with 2000 live pigs and daily feces production of 8.67 tons, cultivating 200 mu dry farming field, near to a residential district.

(79) A device for producing biogas with high methane content by utilizing livestock and poultry feces is designed aiming at the environment, as shown in FIG. 3, comprising a feces collecting pond 1, an acidifying pond 2, a biogas fermentor 3, a biogas purifying device 4, a biogas refining device 5, a biogas compressor 9 and a biogas storage tank 10, because internal utilization of biogas slurry and biogas residue may be realized in the present embodiment, additional arrangement of a treatment device is not needed;

(80) Pretreatment Unit

(81) feces collecting pond 1: design volume 30 m.sup.3;

(82) the feces collecting pond 1 is used for collecting livestock and poultry feces in a unified mode, a collecting pipeline is provided in the bottom of a livestock and poultry captive breeding area, so that feces of livestock and poultry and flushing sewage are automatically collected to the feces collecting pond 1 via inclined pipelines, grids 11 are provided in the feces collecting pond 1 and used for intercepting large-size wastes, so as to prevent blockage of pipelines in a transportation process;

(83) acidifying pond 2: design volume 17.6 m.sup.3;

(84) the acidifying pond 2 is used for acidifying macrofibers in livestock and poultry feces to be simple organic matters to be convenient for subsequent anaerobic bacteria treatment, the acidifying pond 2 is internally provided with a propelling type agitator 21, and externally provided with an automatic doser or dosing device 22, meanwhile, the acidifying pond 2 regulates feces to a proper viscosity to enter subsequent fermentation;

(85) Fermenting Unit

(86) an improved CSTR reactor is adopted as a biogas fermentor 3: design volume 324 m.sup.3;

(87) the structure and composition of the biogas fermentor 3 in the present embodiment are the same as those in embodiment 3.

(88) Biogas Purifying Unit

(89) Similar to embodiment 1.

(90) Biogas Refining Unit

(91) biogas refining device 5: the biogas refining device 5 includes three biogas membrane treatment devices 51, material of the biogas membrane treatment devices 51 is macromolecule polyimide, which is long in service life, compact in structure and safe to use, and separation efficiency reaches up to 95%; a biogas inlet 511, a biogas outlet 512 and an impurity gas outlet 513 are respectively formed in the bottom, the top and the side face each of the biogas membrane treatment devices 51;

(92) a customized form is adopted for the biogas membrane treatment devices 51, and the hollow fibrous membrane is customized as a bent wavy form, so as to increase contact area with biogas, and increase refining efficiency.

(93) Biogas Storage Unit

(94) Biogas compressor 9: model number VW-3/30

(95) used for pressurizing biogas for storage;

(96) biogas storage tank 10: design volume 96 m.sup.3;

(97) used for storing biogas to be distributed to surrounding residents for use.

(98) According to the engineering theory, daily feces treatment capacity is 10 t, daily biogas production capacity is 200 m.sup.3, daily biogas residue production capacity is 0.0675 t, biogas slurry production capacity is 8.279 t, and the methane content of the produced biogas reaches up to 70-82%, which is close to the quality of natural gas.

Embodiment 5

(99) Engineering environment: a dairy farm, with 2000 cows in total; without residential districts and farmlands nearby.

(100) A device for producing biogas with high methane content by utilizing livestock and poultry feces is designed aiming at the environment, as shown in FIG. 4, comprising a feces collecting pond 1, an acidifying pond 2, a biogas fermentor 3, a biogas purifying device 4, a biogas refining device 5, a settling pond 6, an MBR treating pond 7, a sludge thickener 8, a biogas compressor 9 and a biogas storage tank 10, the farm only needs to recycle biogas residues and expects to discharge biogas slurry after treatment, as a result, a biogas slurry treatment unit is additionally provided;

(101) Pretreatment Unit

(102) feces collecting pond 1: design volume 36 m.sup.3;

(103) the feces collecting pond 1 is used for collecting livestock and poultry feces in a unified mode, a collecting pipeline is provided in the bottom of a livestock and poultry captive breeding area, so that feces of livestock and poultry and flushing sewage are automatically collected to the feces collecting pond 1 via inclined pipelines, grids 11 are provided in the feces collecting pond 1 and used for intercepting large-size wastes, so as to prevent blockage of pipelines in a transportation process;

(104) acidifying pond 2: design volume 16 m.sup.3;

(105) the acidifying pond 2 is used for acidifying macrofibers in livestock and poultry feces to be simple organic matters to be convenient for subsequent anaerobic bacteria treatment, the acidifying pond 2 is internally provided with a propelling type agitator 21, and externally provided with an automatic doser or dosing device 22, meanwhile, the acidifying pond 2 regulates feces to a proper viscosity to enter subsequent fermentation;

(106) Fermenting Unit

(107) an improved CSTR reactor is adopted as a biogas fermentor 3: design volume 348 m.sup.3;

(108) the structure and composition of the biogas fermentor 3 in the present embodiment are the same as those in embodiment 3.

(109) Biogas Purifying Unit

(110) Similar to embodiment 1.

(111) Biogas Refining Unit

(112) Similar to embodiment 4.

(113) Biogas Storage Unit

(114) Biogas compressor 9: model number VW-3/30

(115) used for pressurizing biogas for storage;

(116) biogas storage tank 10: design volume 96 m.sup.3;

(117) used for storing biogas to be distributed to surrounding residents for use.

(118) According to the engineering theory, daily feces treatment capacity is 10 t, daily biogas production capacity is 200 m.sup.3, daily biogas residue production capacity is 0.0675 t, biogas slurry production capacity is 8.279 t, and the methane content of the produced biogas reaches up to 70-82%, which is close to the quality of natural gas.

(119) Biogas Slurry Treatment Unit

(120) settling pond 6: design volume 21 m.sup.3;

(121) the settling pond 6 is used for performing further settling treatment on biogas slurry, wherein supernatant enters an MBR treating pond and then is discharged; and precipitates enter to be utilized together with biogas residues;

(122) MBR treating pond 7: internally provided with a PVDF composite plate type membrane;

(123) the MBR treating pond 7 is used for treating biogas slurry and discharging by reaching the standard, and further includes an agitator, an aerator pipe and activated sludge.

Embodiment 6

(124) Engineering environment: a cow and sheep hybrid farm, with 1000 cows and 800 sheep in total, and a number of chickens and ducks; without residential districts and farmlands nearby.

(125) A device for producing biogas with high methane content by utilizing livestock and poultry feces is designed aiming at the environment, as shown in FIG. 4, comprising a feces collecting pond 1, an acidifying pond 2, a biogas fermentor 3, a biogas purifying device 4, a biogas refining device 5, a settling pond 6, an MBR treating pond 7, a sludge thickener 8, a biogas compressor 9 and a biogas storage tank 10, because a planting region is absent near the farm, both biogas slurry and biogas residues need to be discharged after being treated, as a result, a biogas slurry treatment unit and a biogas residue treatment unit are additionally provided.

(126) Pretreatment Unit

(127) feces collecting pond 1: design volume 66 m.sup.3;

(128) the feces collecting pond 1 is used for collecting livestock and poultry feces in a unified mode, a collecting pipeline is provided in the bottom of a livestock and poultry captive breeding area, so that feces of livestock and poultry and flushing sewage are automatically collected to the feces collecting pond 1 via inclined pipelines, grids 11 are provided in the feces collecting pond 1 and used for intercepting large-size wastes, so as to prevent blockage of pipelines in a transportation process;

(129) acidifying pond 2: design volume 24.6 m.sup.3;

(130) the acidifying pond 2 is used for acidifying macrofibers in livestock and poultry feces to be simple organic matters to be convenient for subsequent anaerobic bacteria treatment, the acidifying pond 2 is internally provided with a propelling type agitator 21, and externally provided with an automatic doser or dosing device 22, meanwhile, the acidifying pond 2 regulates feces to a proper viscosity to enter subsequent fermentation;

(131) Fermenting Unit

(132) an improved CSTR reactor is adopted as a biogas fermentor 3: design volume 314 m.sup.3;

(133) the structure and composition of the biogas fermentor 3 in the present embodiment are the same as those in embodiment 3.

(134) Biogas Purifying Unit

(135) Similar to embodiment 1.

(136) Biogas Refining Unit

(137) Similar to embodiment 4.

(138) Biogas Storage Unit

(139) Biogas compressor 9: model number VW-3/30

(140) used for pressurizing biogas for storage;

(141) biogas storage tank 10: design volume 140 m.sup.3;

(142) used for storing biogas to be distributed to surrounding residents for use.

(143) According to the engineering theory, daily feces treatment capacity is 14 t, daily biogas production capacity is 200 m.sup.3, daily biogas residue production capacity is 0.0588 t, biogas slurry production capacity is 7.689 t, and the methane content of the produced biogas reaches up to 82-85%, which is close to the quality of natural gas.

(144) Biogas Slurry Treatment Unit

(145) settling pond 6: design volume 25 m.sup.3;

(146) the settling pond 6 is used for performing further settling treatment on biogas slurry, wherein supernatant enters an MBR treating pond and then is discharged; and precipitates enter to be utilized together with biogas residues;

(147) MBR treating pond 7: internally provided with a PVDF composite plate type membrane;

(148) the MBR treating pond 7 is used for treating biogas slurry and discharging by reaching the standard, and further includes an agitator, an aerator pipe and activated sludge.

(149) sludge thickener 8: with model number of FDY high-concentration thickener;

(150) the sludge thickener 8 is used for concentrating biogas residues and then conveying to the outside, and includes a main body 81, a sludge inlet 82, a water outlet 83 and a sludge outlet 84, the biogas residue outlet A 3121, the biogas residue outlet B 38 and the biogas residue outlet C 61 are all connected to the sludge inlet 82 by pipelines; and

(151) the water outlet 83 is connected to the MBR treating pond (7) by a pipeline.