How to reduce the cost of breeding with black film digester

The black membrane biogas digester, whose scientific name is "fully enclosed anaerobic pond", is an important part of the biogas production device of the farm.

Biogas can be converted into electricity for production and living electricity such as lighting, cooking, and pig house insulation. The "power" of this black membrane digester is extraordinary: the gas cabinet can only store 200 cubic meters of biogas and generate electricity for only 3 to 4 hours a day; The black membrane digester can store two to three thousand cubic meters of biogas, which can generate electricity almost all day and night.

The black membrane biogas digester has the advantages of large anaerobic fermentation volume, long sewage retention period, large amount of biogas production, and low operation and treatment cost, and is very suitable for the treatment of aquaculture excrement in large-scale farms and "blister manure" process farms. There are many advantages of building a black membrane biogas digester, the most intuitive is that the "belly" is very large, and the waste liquid that can be entered and the biogas that can be stored is one or twenty times more than that of the conventional biogas digester. It has natural advantages in terms of construction cost, maintenance management, gas production, power generation, sewage treatment and other aspects, so it has strong economic, social and ecological benefits.

The black membrane digester project can also save on fertilizer costs.

In addition, the project has resulted in savings in sewage treatment fees. The manure is treated by biological composting and anaerobic fermentation to kill toxic and harmful bacteria, viruses and parasite eggs, improve the breeding ground for mosquitoes and flies, and reduce human and animal diseases; It greatly reduces sewage and other harmful impurities, reduces the pollution of groundwater and downstream water quality, and protects the physical and mental health of the local and downstream drinking water population.

At the same time, the black film biogas digester breaks through the building materials of the traditional biogas digester, and it uses impermeable membrane materials, which can effectively replace conventional pool building materials (such as concrete, steel plates, bricks, etc.) at low cost, so as to solve the problems of shortage and high quality of pool building materials.

The black film biogas digester integrates fermentation and gas storage, and the whole anaerobic pond is fully enclosed by using impermeable membrane materials, which has the advantages of simple and convenient construction, fast, low cost, simple process flow, convenient operation and maintenance, long sewage retention time, full digestion, good sealing performance, large daily biogas production, high tensile strength, strong anti-aging and corrosion resistance, good anti-seepage effect, the use of biogas to generate waste heat, black film to absorb sunlight, good heating and thermal insulation effect, automatic sludge discharge device at the bottom of the pool, and small amount of sludge in the pool.

At the same time, the black film biogas digester can also well solve the problems of water seepage, water leakage and gas leakage caused by shrinkage and expansion cracking of concrete biogas projects due to temperature changes, as well as the problems of easy corrosion, easy blockage of pipelines, easy damage to equipment and high operating costs of steel plate biogas projects on the ground. The project is in line with the requirements of the national development strategy and the direction of national industrial development, and the relevant departments are currently studying and promoting.

The only disadvantage of the black film biogas digester is that it occupies a relatively large area, and if you want to generate electricity from biogas, you must also add an anti-corrosion and explosion-proof supercharger.

Advantages of the black membrane biogas digester of the marsh source:

1. The gas cabinet can only store 200 cubic meters of biogas, and can only generate electricity for 3 to 4 hours a day; The black membrane digester can store two to three thousand cubic meters of biogas, which can generate electricity almost all day and night.

2. Equipped with a 110 kilowatt generator set, the electricity generated every day can easily meet the needs of the pig farm, whether it is pig farm lighting, insulation, refrigeration or feed production can be self-sufficient.

3. In addition, the biogas slurry produced by the biogas digester is an excellent fertilizer, which can effectively improve the soil structure and reduce pollution.

For the construction of black film biogas digester, the environmental protection and energy saving of the swamp source are understood.

Thailand's black membrane biogas digester scientific name "cover lagoon" biogas sewage treatment system, in Europe, America and Southeast Asia large-scale pig farms have a wide range of use, in 2003 the technology was introduced to China, low investment, low operating costs, effective degradation of sewage COD, BOD and other concentrations. The basic plain soil of the biogas digester is compacted, and the bottom is made of HDPE (thickness in accordance with ATM American Standard for anti-seepage treatment), and the top is made of HDPE in accordance with ATM American Standard (thickness is sealed with floating covering.

Cover Lagoon "Biogas Digester Features:

1. The construction cost is low, the construction is convenient, the construction period is short, and the cost of each cubic meter of equipment is about 45 90 yuan;

2. Long residence time and good water effect;

3. HDPE film has good heat absorption performance and high gas production;

4. Large gas storage volume to achieve integrated gas storage;

5. It can realize the slag discharge function very well.

This process is the least investment, the most ideal effect of the biogas digester process, in recent years by Guangdong, Fujian, Zhejiang, Jiangsu, Hubei and other places of farm owners warmly.

The "Cover Lagoon" biogas digester system consists of pre-treatment, anaerobic treatment, sludge treatment and post-treatment system. It is the use of the large volume of the biogas digester, under anaerobic conditions, microorganisms and sewage have enough contact time to react, so as to degrade the organic matter in the sewage to a greater extent, and produce biogas, and finally realize the role of purifying sewage water quality.

Calculate the volume of the digester according to the scale of farming: For small and medium-sized farms and large-scale courtyard farmers, the volume of the digester should be calculated according to the number of fermented raw materials, the time of the fermentation raw materials staying in the pond at a certain temperature and the feeding concentration, and the calculation formula is as follows:

v＝（g•ts•hrt）/（r•m）

Where: g - wet weight of raw materials available for fermentation per day (kg);

ts—the percentage (%) of the dry matter content in the feedstock

hrt – the number of days the raw material remains in the pool (hydraulic retention period);

r - bulk density (kg cubic meter) converted into fermentation raw material concentration, r raw material concentration fermentation broth bulk density, fermentation broth bulk density general bulk density of water, that is, 1000 kg cubic meters;

m - effective volume of charging in the pool (%)

Example: A pig farm, raising 250 pigs with small pigs, can produce 1000 kg of fresh pig manure per day, its dry matter content is 20%, the bulk density of fermentation raw materials is 6% 1000 kg cubic meters, the fermentation residence period is 15 days under 35 conditions, only 85% of the tank is required, how big is the biogas digester to be built?

Solution: v (g ts hrt) (r m).

cubic meters) after calculation, the construction of a 60 square meter biogas digester can meet the requirements.

Another introduction: 1For every 100kg of body weight of pigs, the daily amount of manure is 3051kg, and the biogas digester can be built according to this amount.

2.A large pig needs 3 cubic meters; 6 cubic meters for a cow. This figure is largely accurate.

<> advantages: the construction cost and operation cost of the black film biogas digester are low, the construction speed is fast, the follow-up maintenance is convenient, the service life is long, the anaerobic fermentation is sufficient, the gas production volume is large, there is no need for gas storage cabinet or gas storage tank, and the sludge and residue can be discharged in time.

Disadvantages: The black film biogas digester occupies a large area, and when it is used for power generation, it is necessary to lay an anti-corrosion and explosion-proof supercharger.

1. Pros and cons of the construction of black film biogas digester

1. Advantages. (1) The construction cost of the black membrane biogas digester is low, and the cost is only one-tenth or one-fifth compared with the red membrane biogas digester and the biogas digester made of steel pipes.

2) The black membrane biogas digester can make use of the manure and sewage in the farm, which can not only protect the environment, but also produce biogas for people to use.

3) The black membrane biogas digester can dispose of the manure in the farm, thereby destroying the breeding ground of mosquitoes, cutting off an important way of disease transmission, and reducing the probability of animal disease in the farm.

4) The construction of the black film biogas digester is convenient, the construction speed is fast, and the follow-up maintenance is very convenient, and the operating cost is low.

(5) The black film biogas digester has a long service life, a long residence time for organic sewage fermentation, and sufficient anaerobic fermentation.

6) The black film biogas digester has a large gas production volume, and there is no need for a gas storage cabinet or gas storage tank, which saves the cost of gas storage.

7) The sludge and residue in the black membrane biogas digester can be discharged in time.

2. Disadvantages. (1) The area of the black film biogas digester is relatively large.

2) When the black film biogas digester is used for power generation, an anti-corrosion and explosion-proof supercharger needs to be added.

Second, the principle of black film biogas digester

1. The black film biogas digester is a kind of super-large biogas digester integrating fermentation and gas storage, and its treatment principle is the same as that of other anaerobic fermentation processes, mainly through the metabolic function of anaerobic bacteria, in the air isolation environment, the organic matter in the manure and sewage is degraded and biogas (the main component is methane).

2. The anaerobic fermentation in the biogas digester mainly goes through three stages, namely the hydrolysis and acidification stage, the hydrogen production, hydrogen acetic acid production stage and the methane production stage.

<> excavation of the biogas digester: the shape of the biogas digester is generally rectangular, the slope is kept gentle, and the anchor ditch is dug at the edge of the digester. Pipe laying:

Dig a blind ditch according to the situation, and then lay water inlet pipes, outlet pipes, slag discharge pipes, biogas outlet pipes and other pipelines. Impermeable membrane laying: After checking whether the impermeable membrane is damaged, it is cut and laid, and finally buried in the anchor ditch and fixed.

1. Construction method of black film biogas digester

1. Excavation of biogas digester: The shape of the biogas digester is generally rectangular. The size of the earthwork excavation, 50m long, 20m wide, 5m deep, slope length; The size of the pool body is 38m long, 20m wide and 5m deep; The size of the bottom of the pond is 28 m long, 10 m wide, and the volume is 3,500 m.

The size of the excavation of the biogas slurry storage tank is 50 m long, 40 m wide, 5 m deep, and the slope is long; The size of the pool body is 38m long, 40m wide and 5m deep; The size of the bottom of the pond is 28 m long, 20 m wide, and the volume is 8,000 m. The slope should be gentle (slope less than 40°), and the slope should be uniform. Dig an anchoring ditch along the edge of the biogas digester, with an anchoring ditch width of 1m and a depth of 1m; Dig an anchor ditch along the edge of the biogas slurry pond 1m, and the anchor ditch is wide and deep.

2. Pipeline laying: excavate blind ditches according to the situation, and then lay water inlet pipes, outlet pipes, slag discharge pipes, biogas outlet pipes, etc. Among them, the bottom of the slag discharge pipe should be close to the bottom film, the gas pipeline should be able to withstand the pressure of more than 10kpa, and check whether there is air leakage, and the direction of the gas pipeline should be inclined to the direction of the biogas, the shorter the length, the better, and do not coil into a circle.

The gas-water separator is installed at the lowest part of the gas pipe, and each slag discharge pipe is connected to 1 slag discharge tank. The pipe nodes of the inlet pipe and outlet pipe are sealed and fixed by extrusion welding.

3. Bottom membrane laying: use thick HDPE impermeable membrane (50m long, 6m wide), and then check whether the impermeable membrane is damaged, after the inspection, cut according to the specifications of the biogas digester, and then paved in order, and press the impermeable membrane with sandbags after paving.

4. Top membrane laying: use thick HDPE impermeable membrane, cut according to the specifications of the biogas digester, lay it in order, and then bury the top membrane and bottom membrane in the anchoring ditch and fix it.

Second, the pros and cons of black film biogas digester

1. Benefits: (1) The cost of the black film biogas digester is lower than that of the red film biogas digester and the biogas digester made of steel pipes, only tenth.

One, one-fifth.

2) It can make perfect use of livestock manure and sewage in the farm, which not only protects the environment, but also generates biogas for people to use or for power generation.

3) The feces are removed, destroying the breeding grounds of mosquitoes and flies, thus cutting off one of the main transmission routes of the disease and greatly reducing the possibility of disease.

2. Disadvantages: large area of land; When generating electricity, an anti-corrosion and explosion-proof supercharger should be added.

Commonly used biogas accelerators.

The so-called accelerator refers to those substances that are used in small amounts in biogas fermentation and can promote the decomposition of organic matter and increase gas production. The accelerator has three functions in biogas fermentation: to improve the nutritional status of the microorganisms carrying the fermentation beams and meet their nutritional needs; Provide trace elements to promote growth and reproduction for fermentation microorganisms; Improve and stabilize the living environment of methanobacteria and accelerate metabolism.

The main accelerators are as follows.

1) Raw materials for thermal fermentation. Tofu mills, wine mills, flour mills, slaughterhouse scraps, waste water and cow urine, etc. These feedstocks are added directly into the digester, which can increase the temperature of the digester and increase the gas production.

2) Ammonia bicarbonate. The dosage is the feed liquid, that is, 1 cubic meter of feed liquid plus 1 3 kg. Dissolve in water and pour into a biogas digester and stir. It can increase gas production by about 30%.

3) Activated sludge. Mixing 20% 30% activated sludge into the raw materials of the new biogas digester or after a large refueling can speed up the gas production, increase the gas production and purity.

4) Old batteries contain carbon, manganese, zinc, ammonia and other elements. An 8 cubic meter biogas digester, with 17 old batteries, after cutting and smashing, mixed with fermented raw materials, can increase gas production 3 days after being put into the biogas digester. Other elements that contain such elements include peat, mud and rare earth elements.

Seal, add more manure. Unfermented is best, proportions.

Precautions for the construction of black film biogas digester:

1.Do not put weeds, bricks, tiles, stones, etc. in the digester to avoid scratching or clogging the digester.

2.If the biogas digester is not fully bulged, if a large area of water on the surface is caused by rainy weather, it should be drained immediately.

3.The water inlet of the biogas digester (sewage entering the channel) should avoid the blockage of the water inlet caused by the entry of tree branches, plastic bags and other debris.

4.A fence should be set up around the biogas digester, and a reminder sign should be set up within 100m of the biogas site, and fireworks should be strictly prohibited to avoid people other than the staff from approaching.

5.The normal height of the bulging membrane of the gas production roof of the biogas digester is 3-4m, and if it is higher than 5m, it needs to be treated with an exhaust pipe.

The construction of the black film biogas digester of the swamp source, the environmental protection and energy saving of the swamp source.