Do-it-yourself biogas plant for the home: diagram, drawings, reviews. Simple biogas plants at home Installation for producing biogas at home

Owners of private houses located in regions with limited access to traditional fuels should definitely turn their attention to modern biogas plants. Such units make it possible to obtain biogas from a variety of organic waste and use it for personal needs, including heating residential premises.

Gas can be obtained from almost any biomass - waste from the livestock industry, food production, agriculture, foliage, etc. At the same time, you can build such an installation with your own hands.

Mechanism of action of biogas plants

Both homogeneous raw materials and mixtures of various biomass are suitable for producing biogas. A biogas plant is a volumetric sealed structure equipped with devices for supplying raw materials, heating biomass, mixing components, discharging the resulting biogas into a gas collector and, of course, protecting the structure.

In the reactor, under the influence of anaerobic bacteria, rapid decomposition of biomass occurs. During the fermentation of organic raw materials, biogas is released. Approximately 70% of the composition of such gas is represented by methane, the remaining part is carbon dioxide.

Biogas is characterized by excellent calorific value; it has no distinct odor or color. In terms of its properties, biogas is practically in no way inferior to more traditional natural gas.

In developed countries, additional installations are used to purify biogas from carbon dioxide. If you wish, you can buy the same installation and obtain pure biomethane.

Biogas plants on silos. 1 Silo pits. 2 Biomass loading system. 3 Reactor. 4 Post-fermentation reactor. 5 Substrater. 6 Heating system. 7 Power plant. 8 Automation and control system. 9 Gas pipeline system

On average, one cow or other animal weighing half a ton is capable of producing enough manure per day to produce approximately 1.5 m3 of biogas. Daily manure from one average pig can be processed into 0.2 m3 of biogas, and a rabbit or chicken into 0.01-0.02 m3 of fuel.

For comparison: 1 m3 of biogas from manure provides approximately the same amount of thermal energy as 3.5 kg of firewood, 1-2 kg of coal, 9-10 kW/h of electricity.

The simplest recipe for a mixture for producing biogas includes the following components:

• cow manure - about 1500 kg;
• rotted leaves or other organic waste – 3500 kg;
• water – 65-75% of the total mass of the previous components. The water must first be heated to about 35 degrees.

This amount of biomass will be enough to produce biogas for six months of operation with moderate consumption. On average, biogas begins to be released within 1.5-2 weeks after the mixture is loaded into the installation.

Gas can be used to heat a home and a variety of commercial and domestic buildings.

Design of a typical biogas plant

Biogas plant

The main components of a complete biogas system are:

• reactor;
• humus supply system;
• stirrers;
• biomass;
• gas holder;
• separator;
• protective part.

A household installation will have a somewhat simplified design, however, for a complete understanding, you are invited to read the description of all the listed elements.

Biogas plants

Reactor

This part of the installation is usually assembled from stainless steel or concrete. Externally, the reactor looks like a large sealed container, on top of which is a dome, usually spherical in shape.

Currently, the most popular are reactors with a collapsible design, made using innovative technologies. Such a reactor can be easily assembled with your own hands with minimal time investment. If necessary, it can be easily disassembled and transported to another location.

Steel is convenient because you can easily create holes in it to connect other elements of the system. Concrete is superior to steel in terms of strength and durability.

Biomass feeding system

This part of the installation includes a hopper for receiving waste, a supply pipeline for water supply and a screw pump designed to send humus to the reactor.

A front loader is used to load the dry component into the hopper. At home, you can cope with this task without a loader, using various improvised means, for example, shovels.

In the hopper the mixture is moistened to a semi-liquid state. After reaching the desired level of moisture, the screw transfers the semi-liquid mass to the lower compartment of the reactor.

Stirrers

Fermentation of humus in the reactor should occur evenly. This is one of the most important conditions for ensuring intensive release of biogas from the mixture. It is to achieve the most uniform fermentation process of the mixture that the design of a typical biogas plant includes mixers with electric drives.

There are submersible and inclined type mixers. Submersible mechanisms can be lowered into the biomass to the required depth to ensure intensive and uniform mixing of the substrate. Usually such mixers are placed on a mast.

Installation of inclined mixers is carried out on the side surfaces of the reactor. An electric motor is responsible for rotating the screw in the fermenter.

Automated heating system

To successfully produce biogas, the temperature inside the system must be maintained at +35-+40 degrees. For this purpose, automated heating systems are included in the design.

The heat source in this case is a hot water boiler; in some situations, electric heating units are used.

Gas holder

Gas holder

Biogas is collected in this structural element. Most often, the gas holder is placed on the roof of the reactor.

The production of modern gas tanks is usually carried out using polyvinyl chloride, a material that is resistant to sunlight and various adverse natural phenomena.

Gas holder

In some situations, instead of a regular gas tank, special bags are used. Also, these devices allow you to temporarily increase the volume of the produced biogas.

For the manufacture of gas holder bags, a special polyvinyl chloride with elastic properties is used, which can inflate as the volume of biogas increases.

Separator

Separator

This part of the system is responsible for drying waste humus and producing, if necessary, high-quality fertilizers.

The simplest separator consists of a screw and a separator chamber. The chamber is made in the form of a sieve. This allows the biomass to be separated into a solid component and a liquid part.

Press-screw separator

The dried humus is sent to the shipping compartment. The system directs the liquid part back to the receiving chamber. Here the liquid is used to moisten the new feedstock.

The simplest DIY biogas plant

Biogas plant for home

A household biogas installation will have a somewhat simplified design, but its manufacture should be approached with maximum responsibility.

First step. Dig a hole. At its core, a biogas plant is a large pit with a special finish. The most important and at the same time difficult part of manufacturing the system in question is the correct preparation of the walls of the bioreactor and its base.

The pit must be sealed. Strengthen the base and walls with plastic or concrete. Instead, you can purchase ready-made polymer rings with a solid bottom. Such devices make it possible to ensure the necessary tightness of the system. The material will retain its original characteristics for many years, and if necessary, you can easily replace the old ring with a new one.

Second step. Install a gas drainage system. This will save you from the need to purchase and install agitators, due to which the time and money spent on assembling the installation will be significantly reduced.

The simplest version of a gas drainage system is vertically fixed sewer pipes made of polyvinyl chloride with many holes throughout the body.

Select pipes of such length that their upper edges rise slightly above the upper level of the loaded humus.

Third step. Cover the outer layer of the substrate with film insulation. Thanks to the film, conditions will be created for the accumulation of biogas under the dome under conditions of slight excess pressure.

Fourth step. Install the dome and mount the gas exhaust pipe at its highest point.

Gas consumption should be regular. Otherwise, the dome over the biomass container may simply explode. In summer, gas is formed more intensively than in winter. To solve the latter problem, purchase and install suitable heaters.

Procedure and conditions for successful use of a biogas plant

Average specific biogas yield

Thus, it is not difficult to assemble a simple biogas plant yourself. However, for its successful operation, you must remember and follow a few simple rules.

One of the most important requirements is that the loaded organic mass should not contain any substances that can have a negative impact on the vital activity of anaerobic microorganisms. Prohibited inclusions include various types of solvents, antibacterial drugs and other similar substances.

A number of inorganic substances can also lead to a deterioration in the functioning of bacteria. In view of this, it is prohibited, for example, to dilute humus with water remaining after washing clothes or washing a car.

Remember: a biogas installation is a potentially explosive unit, so follow all safety regulations relevant for the operation of any gas equipment.

Thus, even manure and, in principle, almost everything that you previously tried your best to get rid of, can be useful on the farm. You just need to properly build a home biogas installation, and very soon your home will be warm. Follow the recommendations received, and you will no longer have to spend enormous sums on heating.

Good luck!

Read also the article on our website - do-it-yourself hydroponic installation.

Video - Do-it-yourself biogas plant

svoimi-rykami.ru

Do-it-yourself biogas plant

The article on biogas production provided the theoretical basis for the production of methane gas from biomass by anaerobic digestion.

The role of bacteria in the step-by-step transformation of organic substances was explained, with a description of the necessary conditions for the most intensive production of biogas. This article will provide practical implementations of biogas plants, with a description of some home-made designs.

Since energy prices are rising, and many owners of livestock farms and small farms have problems with waste disposal, industrial complexes for the production of biogas and small biogas plants for private homes have become available for sale. Using search engines, an Internet user can easily find an affordable ready-made solution so that the biogas plant and its price meet the needs, get in touch with equipment suppliers and agree on the construction of a biogas generator at home or on the farm.

Industrial complex for biogas production

Bioreactor - the basis of a biogas plant

The container in which anaerobic decomposition of biomass occurs is called a bioreactor, fermenter, or methane tank. Bioreactors can be completely sealed, with a fixed or floating dome, and have a diving bell design. Bell psychrophilic (not requiring heating) bioreactors have the form of an open reservoir with liquid biomass, into which a container in the form of a cylinder or bell is immersed, where biogas is collected.

The collected biogas puts pressure on the cylinder, causing it to rise above the tank. Thus, the bell also serves as a gas holder - a temporary storage facility for the generated gas.

Floating dome bioreactor

The disadvantage of the bell design of the biogas reactor is the impossibility of mixing the substrate and heating it during cold periods of the year. Also a negative factor is a strong odor, and unsanitary conditions due to the exposed surface of part of the substrate.

In addition, part of the resulting gas will escape into the atmosphere, polluting the environment. Therefore, these bioreactors are used only in artisanal biogas plants in poor countries with hot climates.

Another example of a floating dome bioreactor

To prevent environmental pollution and eliminate unpleasant odors, reactors in biogas plants for homes and large industries are designed with a fixed dome. The shape of the structure in the process of gas formation is not of great importance, but when using a cylinder with a dome-shaped roof, significant savings in building materials are achieved. Bioreactors with a fixed dome are equipped with pipes for adding new portions of biomass and selecting spent substrate.

A type of fixed dome bioreactor

Main types of biogas plants

Since the most acceptable design is a fixed dome, most ready-made bioreactor solutions are of this type. Depending on the loading method, bioreactors have different designs and are divided into:

• Portion-based, with a one-time loading of all biomass, and subsequent complete unloading after processing of the raw materials. The main disadvantage of this type of bioreactor is the uneven release of gas during substrate processing;
• continuous loading and unloading of raw materials, thereby achieving uniform release of biogas. Thanks to the design of the bioreactor, during loading and unloading, biogas production does not stop and no leaks occur, since the pipes through which biomass is added and removed are made in the form of a water seal that prevents gas leakage.

Example of a batch bioreactor

Batch biogas reactors can have any design that prevents gas leakage. For example, at one time in Australia, channel methane tanks with an elastic inflatable roof were popular, where a slight excess pressure inside the bioreactor inflated a bubble made of durable polypropylene. When a certain pressure level inside the bioreactor was reached, a compressor was turned on, pumping out the produced biogas.

Channel bioreactors with elastic gas holder

The type of fermentation in this biogas plant can be mesophilic (low heating). Due to the large area of ​​the inflating dome, channel bioreactors can only be installed in heated rooms or in regions with a hot climate. The advantage of the design is that there is no need for an intermediate receiver, but the big disadvantage is the vulnerability of the elastic dome to mechanical damage.

Large channel bioreactor with elastic gas tank

Recently, batch bioreactors with dry fermentation of manure without adding water to the substrate have been gaining popularity. Since manure has its own moisture, it will be sufficient for the life of organisms, although the intensity of reactions will decrease.

Dry-type bioreactors look like a sealed garage with tightly closing doors. Biomass is loaded into the reactor using a front-end loader and remains in this state until the full gas formation cycle is completed (about six months), without the need to add a substrate or mix it.

Batch bioreactor with loading through a hermetically sealed door

DIY biogas plant

It should be noted that in most bioreactors, as a rule, only the gas formation zone is sealed, and the liquid biomass at the inlet and outlet is under atmospheric pressure. Excessive pressure inside the bioreactor displaces part of the liquid substrate into the nozzles, which is why the level of biomass in them is slightly higher than inside the container.

The red lines in the diagram indicate the difference in levels in the bioreactor and pipes

These designs of homemade bioreactors are popular among folk craftsmen who independently make biogas plants with their own hands for the home, allowing for repeated manual loading and unloading of the substrate. When making bioreactors with their own hands, many craftsmen experiment with completely sealed containers, using several rubber tubes from the tires of large vehicles as a gas holder.

Drawing of a gas holder made from tractor inner tubes

In the video below, an enthusiast of homemade biogas production, using barrels filled with bird droppings as an example, proves the possibility of actually producing combustible gas at home by processing poultry house waste into useful fertilizer. The only thing that can be added to the design described in this video is that you need to install a pressure gauge and a safety valve on a homemade bioreactor.

Bioreactor productivity calculations

The amount of biogas is determined by the mass and quality of the raw materials used. On the Internet you can find tables that indicate the amount of waste produced by various animals, but for owners who have to remove manure every day, this theory is of no use, since thanks to their own practice they know the amount and mass of the future substrate. Based on the availability of raw materials renewable every day, it is possible to calculate the required volume of the bioreactor and the daily production of biogas.

Table for obtaining the amount of manure from some animals with an approximate calculation of biogas yield

After the calculations have been made and the design of the bioreactor has been approved, its construction can begin. The material can be a reinforced concrete container poured into the ground, or brickwork sealed with a special coating that is used to treat swimming pools.

It is also possible to build the main tank of a home biogas plant from iron coated with anti-corrosion material. Small industrial bioreactors are often made from large-volume, chemical-resistant plastic tanks.

Construction of a bioreactor from brickwork

In industrial biogas plants, electronic control systems and various reagents are used to correct the chemical composition of the substrate and its acidity level, and special substances are added to the biomass - enzymes and vitamins that stimulate the reproduction and vital activity of microorganisms inside the bioreactor. In the process of development of microbiology, more and more stable and effective strains of methanogen bacteria are being created, which can be purchased from companies involved in the production of biogas.

The graph shows that with the use of enzymes, the maximum biogas yield occurs twice as fast

The need for pumping out and purifying biogas

Constant gas production in a bioreactor of any design leads to the need to pump out biogas. Some primitive biogas plants can burn the resulting gas directly in a burner installed nearby, but instability of the excess pressure in the bioreactor can lead to the disappearance of the flame with the subsequent release of poisonous gas. The use of such a primitive biogas installation connected to a stove is categorically unacceptable due to the possibility of poisoning by the toxic components of unpurified biogas.

The burner flame when burning biogas must be clean, even and stable.

Therefore, almost any biogas installation scheme includes gas storage tanks and a gas purification system. As a homemade cleaning complex, you can use a water filter and a homemade container filled with metal shavings, or purchase professional filtration systems. A container for temporary storage of biogas can be made from inner tubes from tires, from which the gas is pumped out from time to time by a compressor into standard propane cylinders for storage and subsequent use.

In some African countries, inflatable gas holders in the form of a pillow are used for storing and transporting biogas

An improved bioreactor with a floating dome can be considered as an alternative to the mandatory use of a gas tank. The improvement consists of adding a concentric partition, which forms a water pocket, acting like a water seal and preventing the biomass from coming into contact with air. The pressure inside the floating dome will depend on its weight. By passing the gas through a cleaning system and a reducer, it can be used in a household stove, periodically venting it from the bioreactor.

Bioreactor with floating dome and water pocket

Grinding and mixing the substrate in a bioreactor

Stirring the biomass is an important part of the biogas production process, providing bacteria with access to nutrients that may be clumped at the bottom of the digester. In order for biomass particles to be better mixed in the bioreactor, they must be crushed mechanically or manually before loading into the methane tank. Currently, in industrial and home-made biogas plants, three methods of mixing the substrate are used:

1. mechanical stirrers, driven by an electric motor or manually;
2. circulation mixing using a pump or propeller pumping the substrate inside the bioreactor;
3. bubbling mixing using purging of liquid biomass with existing biogas. The disadvantage of this method is the formation of foam on the surface of the substrate.

The arrow indicates the mixing circulation screw in a homemade bioreactor

Mechanical mixing of the substrate inside the bioreactor can be done manually or automatically by turning on the electric motor using an electronic timer. Water jet or bubbling mixing of biomass can only be carried out using electric motors controlled manually or using a software algorithm.

This bioreactor is equipped with a mechanical mixing device.

Substrate heating in mesophilic and thermophilic biogas plants

The optimum temperature for gas formation is the substrate temperature within 35-50ºC. To maintain this temperature, various heating systems can be installed in the bioreactor - water, steam, electric. Temperature control should be carried out using a thermostat or thermocouples connected to an actuator that regulates the heating of the bioreactor.

You also need to remember that an open flame will overheat the walls of the bioreactor, and the biomass inside will burn. A burnt substrate will reduce heat transfer and heating quality, and the hot wall of the bioreactor will quickly collapse. One of the best options is water heating from the return pipe of the home heating system. It is necessary to install a system of electric valves to be able to turn off the heating of the bioreactor or connect the heating of the substrate directly from the boiler if it is too cold.

Electric and water heating system for the bioreactor

Heating the substrate in a bioreactor using heating elements will be beneficial only if alternative electricity is available, obtained from a wind generator or solar panels. In this case, heating elements can be connected directly to a generator or battery, which eliminates expensive voltage converters from the circuit. To reduce heat loss and reduce the cost of heating the substrate in a bioreactor, it is necessary to insulate it as much as possible using various insulation materials.

Insulation of the bioreactor with thermal insulation material

Practical experiments inevitable when building biogas plants with your own hands

No matter how much literature a novice enthusiast of self-production of biogas reads, and no matter how many videos he watches, in practice he will have to learn a lot on his own, and the results, as a rule, will be far from the calculated ones.

Therefore, many beginning craftsmen follow the path of independent experiments in producing biogas, starting with small containers, determining how much gas their small experimental biogas plant produces from the available raw materials. Prices for components, methane output and future costs of building a full-fledged working biogas plant will determine its profitability and feasibility.

In the video above, the master demonstrates the capabilities of his biogas installation, measuring how much biogas is produced in one day. In his case, when eight atmospheres are pumped into the compressor receiver, the volume of the resulting gas after recalculation taking into account the volume of the 24 liter container will be about 0.2 m².

This volume of biogas obtained from a two-hundred-liter barrel is not significant, but, as shown in the following video of this master, this amount of gas is enough for an hour of burning one stove burner (15 minutes multiplied by four atmospheres of a cylinder, which is twice the size of the receiver).

In another video below, the master talks about producing biogas and biologically pure fertilizers by processing organic waste in a biogas plant. It must be borne in mind that the value of environmental fertilizers may exceed the cost of the resulting gas, and then biogas will become a useful by-product of the process of producing quality fertilizers. Another useful property of organic raw materials is the ability to store them for a certain period for use at the right time.

infoelectrik.ru

Do-it-yourself biogas: technology for producing alternative fuel from biological waste

Concerned about the impending energy crisis, humanity is actively trying to develop renewable energy sources.

Along with solar and wind power plants, installations have emerged for producing gaseous fuel called biogas from organic waste.

The great thing about this technology is its simplicity: anyone can implement it on a small scale. So, do-it-yourself biogas – that’s what we’ll be talking about.

If we owe the appearance of solar panels and wind generators to the discoveries of scientists, then in the case of biogas they did not have to invent anything - nature did everything itself. This type of fuel is a product of the vital activity of special bacteria, which are collectively called hydrolytic, acid-forming and methane-forming.

From the name it is not difficult to guess the main component of biogas - it is methane, which is also found in natural gas. In biogas, it accounts for 60% of the total volume. About a third (35%) is carbon dioxide, the remaining 5% is other gases, for example, hydrogen sulfide.

Schematic diagram of a biogas plant

Where do these wonderful microorganisms come from? They are natural microflora that live in the intestines of cattle and decompose their contents. These bacteria are excreted along with the manure, which is used to fuel the new gas generator.

When microbes are settled in a new place of residence, their “menu” can be diversified with other waste. Any organic matter will do: excrement of other animals and birds, plants and sawdust, food industry waste. All this is fermented to form biogas. At the same time, raw materials are transformed into valuable fertilizer.

A prerequisite for the vital activity of methanogens and other bacteria is the absence of air access (such microorganisms are called anaerobic).

Factors influencing biogas production

The volume of biogas produced by a friendly team of microbes under different conditions can vary and depends on a number of factors.

Type of raw material

Most biogas can be obtained from food industry waste containing sugar pulp and large amounts of fat. The least profitable type of raw material is cattle manure.

Manure - raw material for biogas

Temperature

As the temperature rises, the productivity of bacteria increases. According to temperature conditions, gas generators are divided into three types.

Psychrophilic

These are unheated installations in which the temperature is maintained between 18 and 25 degrees. At the moment they are almost never used.

Mesophilic

Thanks to heating, the temperature is maintained within the range from 25 to 40 degrees.

Advantages:

• low energy consumption;
• The amino acid composition of fertilizers is as beneficial as possible.

Flaws:

• relatively low biogas productivity;
• lack of disinfecting effect (the raw materials contain pathogenic bacteria that should be eliminated).

Thermophilic

Intensive heating is used, the temperature exceeds 40 degrees.

Advantages:

• high performance;
• pathogenic bacteria die.

Flaws:

• high energy consumption;
• low quality fertilizers.

Thermophilic manure bioreactor

For each type of raw material there is an optimal temperature regime. Why can't you just heat the reactor to the highest possible temperature? For two reasons:

• due to rising energy costs, the profitability of the installation will decrease;
• As the temperature increases, the amount of free ammonia also increases.

The latter dependence leads to inhibition of gas generation (this gas is toxic to bacteria).

Metabolism and freedom of movement

The raw material must be liquefied enough so that microbes and gas bubbles can move in it. To do this, hot water is added to the installation, bringing the humidity of the load to 85% in winter and up to 92% in summer.

In order for metabolic processes to occur better in the reactor, its contents must be stirred from time to time (approximately every 4 to 6 hours).

Fermentation time

If raw materials are unloaded ahead of schedule, the bacteria will not have time to compensate for the loss in numbers and the productivity of their colonies will drop.

If held for too long, productivity also decreases due to lack of nutrients.

On average, the optimal fermentation time is:

• for the psychrophilic regimen: 30 – 40 days or more;
• for mesophilic: 10 – 20 days;
• for thermophilic: 5 – 10 days.

Acid-base balance

The highest productivity is observed at pH values ​​from 6.5 to 8.5 (depending on the raw material).

Carbon to Nitrogen Ratio

The optimal value again depends on the raw material. There should be 10–20 times more carbon than nitrogen.

Comparison of biogas with more traditional fuels

The strengths of this technology include the following:

1. The raw materials used to produce biogas are an inexhaustible resource and are free of charge.
2. Biogas energy is not tied to a specific location - raw materials for installation can be found in any region.
3. Wide range of applications: biogas can act as a source of heat, electricity and motor fuel.

In terms of construction costs (3–4 thousand euros per kW of power), biogas plants are between nuclear (5 thousand euros per 1 kW) and coal (2 thousand euros per 1 kW) stations.

Installation for biogas production

It has been proven in practice: the greater the power of the installation, the cheaper the energy generated with its help is. Profitability also depends on the type of raw materials used.

Scheme for organizing biogas production at home

When constructing a gas generator with a capacity of over 10 MW, operating on food waste, you will have to spend about 2 thousand euros for each kW of power; at the same time, an installation with a capacity of up to 1 MW, using cow manure as a raw material, will cost 7 thousand euros per 1 kW.

The unit consists of several technological units.

Reactor

It is a solid reinforced concrete container covered with thermal insulation with several technological holes. The reactor must be hermetically sealed to prevent air from entering its interior.

Biomass feeding system

To load raw materials, the installation is equipped with a bunker. Waste is fed here manually or using a conveyor.

A pipe with hot water is also supplied to the reactor.

Stirrers

The mixing blades are mounted on a vertical shaft, the shank of which extends out through a sealed hole in the reactor lid.

The device is driven by an electric motor through a gear reducer.

The electric motor can be turned on manually or automatically.

Automated heating system

Heating is installed in the lower part of the reactor. The coolant can be water or electricity. The heating elements are turned on by a thermostat set to a certain temperature.

Gas holder

This is the container into which the biogas generated in the reactor enters.

Separator

As mentioned above, biogas is a mixture of various gases. The separator allows you to separate methane from impurities for subsequent delivery to the consumer.

The simplest DIY biogas plant for home

A homemade biogas generator, of course, is inferior in characteristics to expensive factory-made units, but it will require significantly lower initial costs.

To build it you will need:

• reinforced concrete rings;
• steel bunker;
• a massive lid made of steel or reinforced concrete (there is a known case when a heavy bell was used as a lid);
• pipelines for supplying water and discharging the finished product.

The reactor volume should exceed the loading volume by 1.5 times.

Installation diagram

In its simplest design, the gas generator is not equipped with heating and a mixing device. Work on the construction of the installation is carried out in the following sequence:

1. A pit of sufficient size is dug, the bottom of which is concreted.
2. Several reinforced concrete rings are lowered into the pit one after another, forming a cylindrical tank from them. All joints should be sealed with bitumen mastic.
3. The concrete container is covered with thermal insulation and waterproofing, after which they begin to backfill the pit.
4. A lid with a tightly closing loading hatch is placed on top of the reactor. During the fermentation of the raw material, high pressure is generated in the reactor, so the lid can be secured with cables for reliability. It would not be superfluous to install a safety valve in it with a counterweight in the form of a weight.
5. A hopper must be attached to the loading hatch.
6. All that remains is to connect the pipelines to the reactor. In this case, a water seal must be installed on the finished product discharge line.

Biomass is prepared as follows:

• You should take 3 parts of cow manure and 7 parts of rotted plant residues - vegetable tops, leaves, peelings, etc.
• The resulting mixture must be diluted with water, thereby raising its humidity to 60% - 70%.

In order to increase productivity, you can use a more advanced installation scheme that includes water heating. The heat generator will be a hot water boiler running on the fuel produced by the installation.

DIY biogas plant - drawing

When loading the raw material, it is enough to warm it up to 35 degrees, after which its temperature as a result of fermentation will rise to 70 degrees.

As practice has shown, a 5-ton loading of biomass makes it possible to obtain an average of about 40 cubic meters daily within 6 months. m of gaseous fuel.

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microclimat.pro

Do-it-yourself biogas plant for a private home: recommendations for the device and an example of arranging a homemade product

A thrifty owner dreams of cheap energy resources, efficient waste disposal and obtaining fertilizers. A DIY home biogas plant is an inexpensive way to make your dream come true. Self-assembly of such equipment will cost a reasonable amount of money, and the gas produced will be a good help in the household: it can be used for cooking, heating the house and other needs.

What is needed to produce biogas

Biogas is formed as a result of fermentation of a biological substrate. It is decomposed by hydrolytic, acid- and methane-forming bacteria. The mixture of gases produced by bacteria is flammable, because contains a large percentage of methane.

Its properties are practically no different from natural gas, which is used for industrial and domestic needs.

If desired, every home owner can purchase an industrial-made biogas plant, but it is expensive, and the investment pays off within 7-10 years. Therefore, it makes sense to make an effort and make a bioreactor with your own hands

Biogas is an environmentally friendly fuel, and the technology for its production does not have much impact on the environment. Moreover, waste products that need to be disposed of are used as raw materials for biogas. They are placed in a bioreactor, where processing occurs:

• The biomass is exposed to bacteria for some time. The fermentation period depends on the volume of raw materials.
• As a result of the activity of anaerobic bacteria, a flammable mixture of gases is released, which includes methane (60%), carbon dioxide (35%) and some other gases (5%). Fermentation also releases potentially dangerous hydrogen sulfide in small quantities. It is poisonous, so it is highly undesirable for people to be exposed to it.
• The mixture of gases from the bioreactor is purified and supplied to a gas tank, where it is stored until it is used for its intended purpose.
• Gas from a gas holder can be used in the same way as natural gas. It goes to household appliances - gas stoves, heating boilers, etc.
• Decomposed biomass must be regularly removed from the fermenter. This is additional labor, but the effort pays off. After fermentation, the raw material turns into high-quality fertilizer, which is used in fields and vegetable gardens.

A biogas plant is beneficial for the owner of a private house only if he has constant access to waste from livestock farms. On average, from 1 cubic meter. You can get 70-80 cubic meters of substrate. biogas, but gas production is uneven and depends on many factors, including biomass temperatures. This complicates calculations.

Biogas plants are ideal for farms. Animal waste can provide enough gas to fully heat residential premises and outbuildings

In order for the gas production process to be stable and continuous, it is best to build several biogas plants, and add the substrate to the fermenters with a time difference. Such installations operate in parallel, and raw materials are loaded into them sequentially. This guarantees a constant production of gas, so that it can be continuously supplied to household appliances.

Ideally, the bioreactor should be heated. Every 10 degrees of heat increases gas production by half. Although heating installation requires investment, it pays off in greater design efficiency

Homemade biogas equipment, assembled from scrap materials, is much cheaper than industrial production plants. Its efficiency is lower, but it is well worth the investment. If you have access to manure and the desire to put in your own effort to assemble and maintain the structure, this is very profitable.

Advantages and disadvantages of the system

Biogas plants have many advantages, but there are also a lot of disadvantages, so before starting design and construction you should weigh everything:

• Recycling. Thanks to a biogas plant, you can get the maximum benefit from waste that would otherwise have to be disposed of. This disposal is less hazardous to the environment than landfilling.
• Renewability of raw materials. Biomass is not coal or natural gas, the extraction of which depletes resources. When farming, raw materials appear constantly.
• Relatively small amount of CO2. When gas is produced, the environment is not polluted, but when it is used, a small amount of carbon dioxide is released into the atmosphere. It is not dangerous and is not capable of critically changing the environment, because... it is absorbed by plants during growth.
• Moderate sulfur release. When biogas is burned, a small amount of sulfur is released into the atmosphere. This is a negative phenomenon, but its scale can be seen in comparison: when burning natural gas, environmental pollution with sulfur oxides is much greater.
• Stable work. Biogas production is more stable than solar panels or wind turbines. While solar and wind energy cannot be controlled, biogas plants depend on human activity.
• Multiple settings can be used. Gas always carries risks. To reduce potential damage in the event of an accident, several biogas plants can be dispersed throughout the site. If a system of several fermenters is properly designed and assembled, it will operate more stable than a single large bioreactor.
• Benefits for agriculture. Some types of plants are planted to obtain biomass. You can choose ones that improve the condition of the soil. For example, sorghum reduces soil erosion and improves its quality.

Biogas also has disadvantages. Although it is a relatively clean fuel, it still pollutes the atmosphere. There may also be problems with the supply of plant biomass. Irresponsible plant owners often harvest it in such a way that they deplete the land and upset the ecological balance.

How to calculate the profitability of an installation

Cow dung is usually used as a raw material for biogas production. One adult cow can produce enough to provide 1.5 cubic meters. fuel; pig – 0.2 cubic meters; chicken or rabbit (depending on body weight) – 0.01-0.02 cubic meters. To understand whether this is a lot or a little, you can compare it with more familiar types of resources.

1 cubic meter biogas provides the same amount of thermal energy as:

• firewood – 3.5 kg;
• coal – 1-2 kg;
• electricity – 9-10 kW/h.

If you know the approximate weight of agricultural waste that will be available over the coming years and the amount of energy required, you can calculate the profitability of a biogas plant.

One of the main disadvantages of biogas production is the smell. The ability to use small compost heaps is a big plus, but you will have to endure the inconvenience and carefully control the process so as not to provoke the spread of pathogens

To put it into the bioreactor, a substrate is prepared, which includes several components in the following proportions:

• manure (best cow or pork) – 1.5 t;
• organic waste (this can be rotten leaves or other components of plant origin) – 3.5 t;
• water heated to 35 degrees (the amount of warm water is calculated so that its mass is 65-75% of the total amount of organic matter).

The calculation of the substrate was made for one laying for six months, based on moderate gas consumption. After about 10-15 days, the fermentation process will give the first results: gas will appear in small quantities and begin to fill the storage. After 30 days, you can expect full fuel production.

Equipment for the production of biogas is not yet particularly widespread in our country. This is largely due to poor awareness of people about the advantages and features of biogas systems. In China and India, many small farms are equipped with makeshift plants to produce additional clean fuel

If the installation is working correctly, the volume of biogas will gradually increase until the substrate rots. The performance of the structure directly depends on the rate of biomass fermentation, which in turn is related to the temperature and humidity of the substrate.

Instructions for self-construction

If you have no experience in assembling complex systems, it makes sense to select online or develop the simplest drawing of a biogas plant for a private home.

The simpler the design, the more reliable and durable it is. Later, when you develop skills in building and handling the system, you can redo the equipment or install an additional installation.

Expensive industrial designs include systems for biomass mixing, automatic heating, gas purification, etc. Household equipment is not that complicated. It is better to assemble a simple installation, and then add elements that are needed

When calculating the volume of the fermenter, you should focus on 5 cubic meters. This installation allows you to obtain the amount of gas necessary to heat a private house with an area of ​​50 square meters, if a gas boiler or stove is used as a heat source. This is an average figure, because The caloric content of biogas is usually not higher than 6000 kcal/m3.

In order for the fermentation process to proceed more or less stably, it is necessary to achieve the correct temperature conditions. To do this, the bioreactor is installed in an earthen pit or reliable thermal insulation is thought out in advance. Constant heating of the substrate can be ensured by placing a water heating pipe under the base of the fermenter

The construction of a biogas plant can be divided into several stages.

Stage 1: preparing the pit for the bioreactor

Almost the entire biogas plant is underground, so a lot depends on how the pit was dug and finished. There are several options for strengthening the walls and sealing the pit - plastic, concrete, polymer rings.

The intensity of fermentation of the substrate and the release of gas depend on the preparation of the walls and bottom of the bioreactor, so the pit is carefully strengthened, insulated and sealed. This is the most difficult and time-consuming stage of work

The optimal solution is to purchase ready-made polymer rings with a solid bottom. They will cost more than available materials, but no additional sealing will be required. Polymers are sensitive to mechanical loads, but are not afraid of moisture and chemically aggressive substances. They cannot be repaired, but if necessary they can be easily replaced.

Stage 2: arrangement of gas drainage

Purchasing and installing special mixers for biogas plants is an expensive proposition. The system can be made cheaper by installing gas drainage. It consists of vertically installed polymer sewer pipes with many holes made in them.

For gas drainage, you can choose metal or polymer pipes. The former are stronger, and the latter are more resistant to chemical influences. It is better to give preference to polymers, because metal will quickly rust and rot

When calculating the length of drainage pipes, you should focus on the planned filling depth of the bioreactor. The tops of the pipes must be above this level.

Stage 3: arrangement of the insulating layer

You can immediately load the substrate into the finished bioreactor. It is covered with a film so that the gas released during the fermentation process is under slight pressure. When the dome is ready, this will ensure a normal supply of biomethane through the outlet pipe.

Stage 4: installation of the dome and pipes

The final stage of assembling the simplest biogas plant is the installation of the dome top part. At the highest point of the dome, a gas exhaust pipe is installed and extended to the gas holder.

The free space of the bioreactor to some extent serves as a gas storage facility, but this is not enough for the safe operation of the installation. Gas must be consumed constantly, otherwise an explosion from excess pressure under the dome is possible

The bioreactor container is closed with a tight lid. To prevent biomethane from mixing with air, a water seal is installed. It also serves for gas purification. A release valve must be provided that will operate if the pressure in the fermenter is too high.

Two ways to heat a bioreactor

Microorganisms that process the substrate are constantly present in the biomass, but for their intensive reproduction they need a temperature of 38 degrees or higher. For heating during cold periods, you can use a coil connected to the home heating system or electric heaters. The first method is more economical, so it is used more often.

The easiest way to arrange heating from below is to lay a pipe from the heating system, but the efficiency of such a heat exchanger is relatively low. It is better to arrange external heating, ideally steam, so that the biomass does not overheat

The biogas plant does not have to be buried in the ground; there are other options for arrangement. An example of the operation of a system assembled from barrels is shown in the video below.

Videos on assembly and arrangement of the system

Although there is nothing complicated in assembling and arranging biogas equipment, you need to be extremely attentive to details. Errors are unacceptable, because may lead to explosions and destruction. We offer video instructions that will help you understand the design of the plants, assemble them correctly and supplement them with useful devices for more convenient use of biogas.

The video describes how a standard biogas plant works and works:

An example of a homemade biogas plant. Video tutorial on how to set up a system with your own hands:

Video instructions for assembling a biogas plant from a barrel:

Description of the manufacturing process of substrate mixers:

Detailed description of the operation of a homemade gas storage:

No matter how simple the biogas installation chosen for a private home may be, you should not skimp on it. If possible, it is better to buy a collapsible industrial bioreactor. If not, make it from high-quality and sustainable materials: polymers, concrete or stainless steel. This will allow you to create a truly reliable and safe gas supply system at home.

sovet-ingenera.com

How to install heating in a private house with your own hands

Biogas is a gas produced by the fermentation of biomass. In this way you can get hydrogen or methane. We are interested in methane as an alternative to natural gas. Methane is colorless and odorless and is highly flammable. Considering that the raw materials for producing biogas are literally under your feet, the cost of such gas is significantly less than natural gas, and you can save a lot on this. Here are the numbers from Wikipedia “From a ton of cattle manure, 50-65 m³ of biogas is obtained with a methane content of 60%, 150-500 m³ of biogas from various types of plants with a methane content of up to 70%. The maximum amount of biogas is 1300 m³ with a methane content of up to 87% can be obtained from fat.", "In practice, 300 to 500 liters of biogas are obtained from 1 kg of dry matter."

Tools and materials:
-Plastic container 750 liters;
-Plastic container 500 liters;
-Plumbing pipes and adapters;
-Cement for PVC pipes;
-Epoxy adhesive;
-Knife;
-Hacksaw;
-Hammer;
- Open-end wrenches;
-Gas fittings (details in step 7);

Step one: a little more theory
Some time ago, the master made a prototype of a biogas plant.

And he was bombarded with questions and requests to help with the assembly. As a result, even the state authorities became interested in the installation (the master lives in India).

The next step the master had to do a more complete installation. Let's consider what it is.
-The installation consists of a storage tank in which organic material is stored, and microorganisms process it and release gas.
-The gas thus obtained is collected in a reservoir known as a gas header. In the floating type model, this tank floats in suspension and moves up and down depending on the amount of gas stored in it
-The guide pipe helps the gas collector tank to move up and down inside the storage tank.
-Waste is fed through a supply pipe inside the storage tank.
-The completely recycled suspension flows through the outlet pipe. It can be collected, diluted and used as plant fertilizer.
-From the gas manifold, gas is supplied through a pipe to consumer appliances (gas stoves, water heaters, generators)

Step two: choosing a container
To select a container, you need to consider how much waste can be collected per day. According to the master, there is a rule where 5 kg of waste requires a container of 1000 liters. For a master it is approximately 3.5 - 4 kg. This means the capacity needed is 700-800 liters. As a result, the master purchased a capacity of 750 liters.
Installation with a floating type of gas manifold, which means you need to select a container such that gas losses are minimal. A 500 liter tank was suitable for these purposes. This 500 liter container will move inside the 750 liter container. The distance between the walls of the two containers is about 5 cm on each side. Containers need to be selected that will be resistant to sunlight and aggressive environments.

Step Three: Preparing the Tank
Cuts the top off the smaller tank. First, he makes a hole with a knife, then saws it with a hacksaw blade along the cut line.

The top part of the 750 liter container also needs to be cut off. The diameter of the cut part is the lid of the smaller tank + 4 cm.

Step four: supply pipe
An inlet pipe must be installed at the bottom of the larger tank. Biofuel will be poured inside through it. The pipe has a diameter of 120 mm. Cuts a hole in the barrel. Installs the knee. The connection is secured on both sides with cold welding epoxy glue.

Step five: pipe for draining the suspension
To collect the suspension, a pipe with a diameter of 50 mm and a length of 300 mm is installed in the upper part of a larger tank.

Step six: guides
As you already understood, a smaller one will “float” freely inside a large container. As the internal tank fills with gas, it will heat up and vice versa. To allow it to move freely up and down, the master makes four guides. In the “ears” he makes cutouts for a 32 mm pipe. Secures the pipe as shown in the photo. Pipe length 32 cm.

4 guides made of 40 mm pipes are also attached to the inner container.

Step seven: gas fittings
The gas supply is divided into three sections: from the gas manifold to the pipe, from the pipe to the cylinder, from the cylinder to the gas stove.
The master needs three 2.5 m pipes with threaded ends, 2 taps, sealing gaskets, threaded adapters, FUM tape and brackets for fastening.

To install the gas fittings, the master makes a hole in the upper part (formerly the lower part, i.e. the 500 liter cylinder is turned upside down) in the center. Installs the fittings, seals the joint with epoxy.

Step Eight: Assembly
Now you need to place the container on a flat, hard surface. The installation location should be as sunny as possible. The distance between the installation and the kitchen should be minimal.

Installs smaller diameter tubes inside the guide tubes. The pipe for draining excess suspension is extended.

Extends the inlet pipe. The connection is fixed using cement for PVC pipes.

Installs a gas accumulator inside a large tank. Orients it along the guides.

Step nine: first launch
For the initial start-up of a biogas plant of this volume, about 80 kg of cow manure is needed. Manure is diluted with 300 liters of non-chlorinated water. The master also adds a special additive to accelerate the growth of bacteria. The supplement consists of concentrated juice of sugar cane, coconut and palm trees. Apparently it's something like yeast. Fills this mass through the inlet pipe. After filling, the inlet pipe must be washed and a plug installed.

After a couple of days, the gas accumulator will begin to rise. This began the process of gas formation. As soon as the storage tank is full, the resulting gas must be vented. The first gas contains many impurities, and there was air in the storage tank.

Step ten: fuel
The process of gas formation has started and now we need to figure out what can and cannot be used as fuel.
So, the following are suitable for fuel: rotten vegetables, peelings of vegetables and fruits, unusable dairy products, overcooked butter, chopped weeds, waste from livestock and poultry, etc. A lot of unusable plant and animal waste can be used in the installation. The pieces need to be crushed as finely as possible. This will speed up the recycling process.

Do not use: onion and garlic peelings, eggshells, bones, fibrous materials.

Now let's look at the question of the amount of loaded fuel. As already mentioned, such a capacity requires 3.5 - 4 kg of fuel. Fuel processing takes from 30 to 50 days, depending on the type of fuel. Every day adding 4 kg of fuel, within 30 days about 750 g of gas will be produced from it daily. Overfilling the unit will lead to excess fuel, acidity and lack of bacteria. The master reminds that according to the rules, 5 kg of fuel is needed daily per 1000 liters of volume.
Step Eleven: Plunger
To make loading fuel easier, the master made a plunger.

Features of organic waste processing in home bio-installations. Processing organic waste without access to oxygen is a highly effective way to obtain high-quality organic fertilizers and an environmentally friendly energy carrier, which is biogas. Moreover, this method of waste processing is absolutely safe for the environment.

Biogas is a gas that is approximately 60% methane and 40% carbon dioxide (CO2). A variety of microbial species metabolize carbon from organic substrates under oxygen-free conditions (anaerobic) (Table 4).

Biogas yield (m3) from one ton of organic matter
Type of organic raw materials	Gas output, m3 per ton of raw material
Cattle manure
Pig manure
Bird droppings
Horse dung
Sheep manure
Corn silage
Grass silage
Fresh grass
Sugar beet leaves
Ensiled sugar beet leaves

This is the process of so-called putrefaction or oxygen-free fermentation.

Methane fermentation is a complex anaerobic process (without air access), which occurs as a result of the vital activity of microorganisms and is accompanied by a number of biochemical reactions. The fermentation temperature is 35°C (mesophilic process) or 50°C (thermophilic process). This method should be assessed as a local environmental protection measure, which at the same time improves the energy balance of the economy, since it is possible to organize a low-waste, energy-saving economy.

During the processing of liquid manure with a moisture content of up to 90-91% in a methane digestion unit, three primary products are obtained: dewatered sludge, biogas, and liquid waste. Dehydrated sludge is odorless, does not contain pathogenic microflora, and the germination of weed seeds is reduced to zero. In general, dewatered sludge is a highly concentrated, disinfected, deodorized organic fertilizer suitable for direct application to the soil. It is also used as a raw material for the production of vermicompost. Methane fermentation improves the quality of the substrate. This occurs due to the fact that during methane fermentation without access to oxygen, ammonia nitrogen is converted into ammonium form, which subsequently, in the process of aerobic fermentation, reduces nitrogen losses. The substrate obtained from fermented manure and litter helps increase crop yields by 15-40%.

Since 1920, biogas has been produced on a large scale from sewage wastewater. In European cities, city truck fleets began to be converted to run on biogas in 1937. During World War II and the post-war era, the production of biogas from organic waste was researched and promoted. Due to the decline in oil prices, the development of biogas technologies ceased in the 60s. In developing countries, simple biogas plants have become widespread. Millions of such “backyard” type installations have already been created in China. About 70 million units have been built in India. In developed countries, after the 1973 crisis, large-volume biogas plants became widespread. It has become possible to quickly ferment sewage in anaerobic filters at a relatively low fermentation temperature.

Among the variety of biogas plants that operate today in many countries around the world, there are plants with reactor volumes from several to several thousand cubic meters. Conventionally, they can be divided into:

Small, or household - reactor volume up to 20 m3;

Farm - 20-200 m3;

Medium - 200-500 m3;

Large - over 500 m3

Advantages of biogas plants:

Agronomic - the ability to obtain highly effective organic fertilizers;

Energy - biogas production;

Environmental - neutralization of the negative impact of waste on the environment;

Social - improving living conditions, which is especially important for residents of rural areas.

Many countries are widely using the potential that this method of waste processing provides. Unfortunately, in Ukraine even now it remains somewhat exotic and is used in practice in isolated cases, in particular for the anaerobic processing of organic waste for fertilizer, which is relevant in the current conditions. Even the energy crisis did not stimulate the development of this energy production technology, while in some countries, such as India and China, national programs for recycling waste in bio-based plants have been operating for a long time. A significant percentage of the energy needs in many European countries are provided by this technology, and in England, even before 1990, it was planned to provide the rural population with gas of “own production.”

Figure 41. Biogas plantFigure 42.Indian

biogas plant in Ethiopia

Without discounting the importance of large-scale plants, it is worth paying close attention to the advantages of small biogas plants. They are cheap, available for construction by individual and industrial methods, simple and safe to maintain, and the products of organic waste processing in them - biogas and high-quality organic fertilizers - can be used directly for the needs of the farm without the cost of transportation.

The advantages of small biogas plants include the availability of local materials for the construction of the plant, the possibility of maintenance by the owner, the absence of the need for accounting, transportation over long distances and preparation for the use of biogas.

Small biogas plants also have certain disadvantages compared to large ones. Here it is more difficult to automate and mechanize the processes of preparing the substrate and the operation of the installations themselves; grinding the substrate, its heating, loading and unloading, storage before and after processing, which predetermines the need for containers for storing fermented waste, is problematic. In addition, in order to bring the substrate to the concentration required for fermentation, you should have another container and a certain amount of water. To reduce water costs, it is worth considering the possibility of its reuse. Problems also arise with dehydration of the fermented mass. Most often, units that are used for mechanization of work (grinding, mixing, heating, feeding processed products, etc.) in large installations are unsuitable for use in small ones due to their technical parameters and high cost.

Homestead plants produce small volumes of biogas, so it is more difficult to organize the processes of its dehydration and purification from impurities of non-combustible components.

The problems of operating small biogas plants include the unevenness of the process of producing biogas at different times of the year. During the summer period of operation, problems arise due to the fact that in the presence of a gas heater, less biogas of own production will be spent on heating the substrate; its commercial quantity will be greater than in the winter. In the summer, when animals are turned out to pasture, the amount of waste, the raw material for the bioreactor, decreases. As part of such installations, it is inappropriate to provide units for significant accumulation of biogas - when more gas is produced than is needed for the economy, it will simply have to be released into the atmosphere.

But no matter what, anaerobic processing of organic waste is a highly effective and profitable way to obtain high-quality organic fertilizers and environmentally friendly energy carriers. Small household biogas-humus plants with a reactor of up to 20 m3 can be recommended for installation in almost every rural yard where organic waste accumulates.

Among the main modern trends in the development of biogas technologies are the following:

Fermentation of multicomponent substrates;

The use of “dry” type of anaerobic fermentation for the production of biogas from energy plant crops;

Creation of centralized biogas stations with high productivity and the like.

There are four main types of implementation of anaerobic digestion technology, namely: covered lagoons and digesters operating in the mode of a mixing reactor and a reactor with a biomass carrier. The technical and economic feasibility of using one type or another depends mainly on the moisture content of the substrates and climatic conditions in the area where the biogas plant is located. The type of bioreactor used affects the total duration of the methanization process.

Indoor lagoons are advisable to use in warm and temperate climates - for liquid manure waste that does not contain inclusions with significant hydraulic coarseness. Such reactors are not specially heated, and therefore they are considered not intensive. The duration of decay of organic matter to stabilize waste significantly exceeds that in reactors with intensive fermentation mode.

Reactors with intensive fermentation mode include heated reactors of various types. There are two fundamental differences between the designs of such reactors, which depend on the characteristics of the fermented substrates. In reactors of the first type, substrates with a predominance of liquid manure waste are fermented. The most common type of such reactors are cylindrical concrete or steel with a central column, covered with an elastic membrane, which serves to seal the structure and accumulate the generated biogas. Such reactors operate on the principle of complete mixing, when each fresh portion of the mixture of initial substrates is mixed with the entire fermentable mass of the reactor. The basic design of such reactors is shown in Figure 43.

Fig.43 . Vertical type digester

2 - substrate overflow;

3 - air supply pump;

4 - thermal insulation of the methane tank;

5 - central column, which supports the gas tank membrane from falling;

6 - mixing device;

7 - drive of the mixing device;

8 - service area;

9 - gas tank membrane;

10 - methane tank filling level;

11 - height of raising of the gas tank membrane;

12 - heating pipelines

Another type of reactor for liquid substrates is the horizontal type, operating on the displacement principle. In such structures, the initial substrate mixture is supplied from one side and removed from the other. In this case, organic matter undergoes successive transformations due to a consortium of microorganisms already present in the original substrate. Such reactors can be considered less efficient in terms of the intensity of the process, however, in them, due to the spatial separation of the entry points of fresh substrates and the exit points of fermented ones, it is possible to minimize the risk of the release of an unfermented portion of fresh substrates along with the fermented substrate (which is removed from the methane tank). It is advisable to use reactors of this type for small volumes of fermented substrates.

The following type of reactors are designed for the methanization of dry organic mixtures, in which cosubstrates from energy plant crops predominate. Reactors of this type are becoming widespread along with the spread of technologies for “dry” fermentation of energy plant crops. A characteristic feature of such methane tanks is that they are designed as full displacement reactors.

From a technological point of view, the process of producing biogas from organic matter is multi-stage. It consists of the process of preparing substrates for fermentation, the process of biological decomposition of the substance, post-fermentation (optional), processing of the fermented substrate and extracted biogas, preparing them for use or disposal on site. Figure 2 shows a schematic flow diagram of a typical farm biogas station for co-digestion of manure waste and organic co-substrates.

Rice. 44. Schematic diagram of a typical farm biogas station

Preparing the substrate for fermentation involves collecting and homogenizing (mixing) the substrate. To collect the substrate, depending on its design quantity, a storage tank is built, equipped with a special mixing device and a pump, which will subsequently supply the prepared substrate to the reactor (methane tank). Depending on the types of substrates, the substance preparation system can be complicated by modules for grinding or sterilizing cosubstrates (if necessary).

After preliminary preparation, a pre-calculated amount of substrate is pumped using pumps through a pipeline system to the reactor. In a reactor (methane tank), the substrate is subject to destruction with the participation of microbiocenosis over a calculated period of time, depending on the selected temperature regime. The digester tank is equipped with a system of heating pipelines, a mixing device (to eliminate the possibility of stratification of the medium and the formation of a crust, uniform division of substances nutritious for the microbiological environment and leveling the temperature of the substrate), systems for removing the extracted biogas and discharging the fermented substrate. In addition, the digester tank is equipped with an air supply system, a small amount of which is needed to purify biogas from hydrogen sulfide by biochemical precipitation.

The degree of decomposition of organic matter at the time of completion of active gas formation approaches 70-80%. In this state, the fermented organic mass can be fed to a separation system to be divided into solid and liquid parts in a special separator.

There are several schemes for utilization of extracted biogas, the main one of which is the combustion of biogas in a cogeneration plant directly on site, with the production of electricity and heat, which are used for the own needs of the farm and the biogas station. In addition, part of the electrical energy is transmitted to the power grid.

The main substrate for anaerobic digestion, as a rule, is animal and poultry manure, as well as slaughterhouse waste. Substrates of this origin contain the most microorganisms necessary for the organization and progress of the methane fermentation process, since they are already present in the stomach of animals.

As the experience of Germany shows, most installations operate on a mixture of cosubstrates with different proportions. The country implemented a special program to collect data from more than 60 representative operating biogas plants and analyzed them. There are quite a lot of stations (about 45%), where manure is used as the main substrate in a volume of 75-100% of the total volume of the mixture. However, there are also many stations where the slurry content is less than 50%. This indicates that biogas plants in Germany largely utilize the potential not only of manure waste, but also of a variety of additional co-substrates when producing biogas.

Analysis of data on biogas production at these stations showed that with an increase in cosubstrate particles in the mixture, the specific yield of methane increases. The most common type of cosubstrate is corn silage. It is purchased from farmers in crushed form, ready for loading into reactors, and stored in open fenced areas. In addition to corn silage, grass silage, grain chaff, fat waste, grass clippings, whey, food and vegetable waste, and the like are also widely used.

In the minds of the Ukrainian farmer, a biogas plant is strongly associated exclusively with the processing of waste from large farms. The main incentive for the construction of biogas plants in Ukraine, which is often not very effective, remains the need for wastewater treatment. The possibility of obtaining high-quality organic fertilizers is also interesting for the farmer. The energy aspects of biogas production remain underutilized due to low tariffs for electricity and heat, resulting in very low return on investment for biogas plants through energy sales.

Of course, in order for biogas technologies to begin to actively develop, it is necessary to legalize the system of “green” tariffs for all types of renewable electrical and thermal energy, as has already happened in many countries of the world, and not only in developed ones.

Another way to increase the efficiency of biogas plants is to actively use additional substrates for fermentation, such as corn silage. An excellent example of an effective biogas plant is the BGU of the German company Envitek Biogas. The company's standard BGU is equipped with a 2500 m3 reactor and a cogeneration unit with an electrical power of 500 kW. The basic supplier of raw materials for such an installation could be a typical German pig farm with a population of 5,000 pigs. An increase in biogas yield is achieved by adding corn silage. For continuous operation of the installation throughout the year, 6000 tons of silage are needed, or 300 hectares of land with a silage yield of 20 t/ha.

Brief technical characteristics of biogas company LLC					Biodieseldnepr"
Installation brand	Reactor volume, m 3	Installed power		Biogas output	Electricity production, kW	Production heat, kW	Biogasoline

Liquid waste is a disinfected, deodorized liquid that contains up to 1% of suspended substances and contains fertilizing elements. Centrate is an excellent organic feed for agricultural crops, the use of which is convenient both for watering and irrigation. After post-treatment, liquid waste can even be used as process water.

Biogas is used to produce electrical and thermal energy. By burning 1 m3 of biogas, you can get 2.5-3 kW/hour of electricity and 4-5 kW of thermal energy. At the same time, 40-60% of biogas is used for the technological needs of the installation. Biogas under pressure 200-220 atm. can be used to refuel vehicles.

In addition to producing energy and fertilizers during waste fermentation, biogas plants act as treatment facilities - they reduce chemical and bacteriological pollution of soil, water, air and convert organic waste into neutral mineralized products. Compared to the energy of small rivers, wind and solar energy, where installations use environmentally friendly energy sources (passively clean plants), bioenergy plants (BES) are actively clean, which eliminates the environmental hazards of the products that are their raw materials.

There are many types of biogas plants in use around the world. They contain devices for receiving plant manure, metatanks and energy power units.

Methane tanks differ from each other in the design of devices for mixing the mass during fermentation. The most frequent mixing is carried out using a shaft with blades, which ensures layer-by-layer mixing of the fermented mass. In addition, they are mixed by hydraulic and mechanical devices, which ensure that the mass is taken from the lower layers of the digester and fed to the upper part. Biogas plants that operate in intensive mode have aerobic (oxygen) fermentation chambers, where the mass is prepared for fermentation, and anaerobic (methane) fermentation. There are also devices for mixing the mass, made in the form of a shaft with blades, located along the vertical axis of the housing and attached to the top of the floating gas cap. Mixing of the mass in the reactor occurs due to the rotation of the shaft with blades and the movement of the floating floor. Some devices only provide breaking of the crust that forms on the surface of the mass of the workpiece. Mixing is also achieved by using partitions and a double-acting siphon, which ensures alternate pouring of mass from the lower zone of one section to the upper zone of the second and, vice versa, by regulating the gas pressure. Sometimes the methane tank is designed in the form of a sphere or cylinder, which must be able to rotate around its geometric axis.

In Ukraine, due to the sharp rise in price of natural gas and the depletion of its resources, interest in biogas technologies has increased. Today, small biogas plants are not yet used in homesteads and small farms in the country. At the same time, for example, in China and India, millions of small methane tanks have been built and are successfully operating. In Germany, out of 3,711 operating biogas plants, about 400 are farm biogas plants, in Austria there are more than 100 of them.

Fig.45.German biogas plant (farm)

Fig.46 Diagram of a biogas plant for a farm:

1 - collections for pus (schematically); 2 - biomass loading system; 3- reactor 4 fermentation reactor; 5 - substrate; 6 - heating system; 7 - power plant; 8 - automation and control system; 9 - gas pipeline system.

Fig.47 Diagram of a biogas plant for a farm

According to the testimony of veterans of the Great Patriotic War, during the liberation of Romania they saw in many peasant households small primitive biogas installations that produced biogas used for domestic needs.

Among the small biogas plants, the ones developed by Biodieseldnepr LLC (Dnepropetrovsk) should be mentioned. They are intended for processing by anaerobic digestion (without access of oxygen) of organic waste from household plots and farms. Such installations make it possible to process 200-4000 kg of waste daily in a continuous mode or 1000-20000 kg in a cyclic mode for five days. At the same time, it is ensured that at least 3 m3 of biogas is obtained per 1 m3 of reactor volume, which can be used in installations to generate heat or electricity necessary to cover the energy needs of the installation; for gas supply systems (room lighting, cooking), heating and hot water supply for households; in plants for the synthesis of bioethanol and biodiesel fuel, as well as an appropriate amount of high-quality organic fertilizer, ready to be applied to the soil.

The industrial and commercial company "Dnepr-Desna" (Dnepropetrovsk) has developed a small bioenergy plant "Biogas-6MGS 2", intended for private households (3-4 cows, 10-12 pigs, 20-30 poultry). The productivity of this installation is approximately 11 m 3 of biogas per day.This amount of gas covers the heating needs of a 100 m 2 room and hot water for a family of five people.

The experience of introducing a small biogas plant in the village of Leski, Kenyan district, Odessa region, deserves attention. The biogas plant was developed and manufactured by a private company in Dnepropetrovsk.

The installation was installed within the framework of the project “Model for the disposal of livestock waste in the Danube Delta region”, developed by a group of Odessa non-governmental organizations within the framework of the program of small environmental projects with the financial support of the British Environment Fund for Europe and with the assistance of the Ministry of Environment and Food and British Agriculture and British Council.

Under normal loading and operation, a biogas plant with a reactor volume of 3 m3 will be able to produce up to 3 m3 of biogas per day by processing waste from 100 poultry, or 10 pigs, or 4 cows. These are the minimum requirements for the operation of the installation.

The reactor is installed on the surface of the earth. This is due, firstly, to the design of the reactor. Biological raw materials are loaded into it from below, through an extruder, and waste material is drained through the top, which distinguishes this design from others, in which loading occurs from above and selection from below. The second reason for the above-ground placement is the high level of soil water in the village - at a depth of 50 cm. In winter, heating of manure in the reactor is carried out using electricity, and in summer, solar energy is sufficient.

The resulting gas is used primarily for cooking - the gas pipeline is connected to the summer kitchen. It is necessary to maintain a temperature in the reactor of 30-35°C and monitor the production of biogas. Manure processed in a bioreactor must be unloaded in a timely manner.

As already noted, in Western Europe, biogas plants are being widely implemented on livestock farms. A feature of such installations is the introduction of power units, where biogas is converted into electricity, and the use of plant mass, in addition to manure.

It is advisable to use small feeders to feed plant mass into methane tanks. The capacity of the receiving hopper of such a feeder is 4 m3, the total length of the conveyor is 6 m; drive power - 7.5 kW.

The S-BOKH50 mini-power unit can be effectively used to complete farm biogas plants. The electrical power of such a power unit ranges from 25 to 48 kW; thermal power - from 49 to 97 kW.

Germany offers small compact biogas plants with a power of 30 and 100 kW, which are designed for the use of manure and corn silage. The 30 kW installation includes a storage loader for 5 m3 of solid organic matter, a concrete fermenter for 315 m3 and a USH gas motor with a power of 30 kW of electrical energy and 46 kW of thermal energy. To ensure the operation of a 30 kW biogas plant when using a mixture of 50% manure and 50% silage, it is necessary to have 5-7 hectares of corn. The 100 kW installation has a corn silage receiver-feeder with a capacity of up to 20 m3, a fermenter with a capacity of 1200 m3 and a gas engine with a power of 100 kW of electrical energy and 108 kW of thermal energy. When used to ensure the operation of a 100 kW biogas plant, a mixture of 50% manure and 50 % corn silage you need to have 30 hectares of corn.

It should be noted that when introducing biogas plants, foreign companies take an individual approach to each farmer. For a specific farm, after an appropriate examination of the available types and resources of biomass and determining the main purposes of using the installation, the appropriate technology (technological mode) is developed or selected, on the basis of which the installation (process line) is designed. The configuration depends on the selected technology. Most companies develop and install biogas plants on a turnkey basis. When using biogas plants, much attention is paid to technologies for preparing biomass for fermentation, since energy indicators depend on the quality of the raw materials. To effectively manage a biogas plant, it is advisable to use measuring and control technology.

The most effective technology is considered to be fermentation, which converts biogas energy into electrical and thermal energy.

The growing popularity of alternative methods for generating heat and electrical energy has led to the desire of many owners of country houses and cottages to gain a certain autonomy from external energy suppliers. Moreover, “purchased” energy shows a constant tendency to increase prices, and the maintenance of a country farm is becoming more and more expensive every day. The biogas plant is an excellent alternative to external energy sources. At a minimum, it can provide the house with flammable gas for the stove, and when the power increases (if there is enough of your own or purchased waste), it can provide both heating and electricity for both the house and the entire household.

Who needs biogas plants

Biogas plants are used to produce combustible gases from biological raw materials. So they are needed wherever flammable gases are required. That is, to obtain thermal and electrical energy.
First of all, biogas plants are necessary for those farms where there is a lot of raw materials in the form of biological waste. In this way, it is possible not only to make production waste-free, but also to significantly increase its profitability - due to independent energy production and the absence of costs for the purchase of both thermal and electrical energy.

Vladimir Rashin, a designer of a biogas plant and a farmer from Perm, has proven from his own experience that agricultural production, which independently disposes of waste using an appropriate device, fully meets its needs for thermal and electrical energy, as well as combustible gas. In his quail farm, biogas is used to heat premises (both residential, utility and industrial), to generate electricity, in kitchen stoves, and also to refuel vehicles - all cars on the Rashin farm run on biogas. In this case, the main raw material for the biogas plant is quail droppings. The output, in addition to biogas, also produces organic fertilizer, which also brings additional income to the farm.

Biogas plants like Vladimir Rashin's can significantly increase the profitability of any agricultural production. Not only manure, but also various waste from wood processing industries (bark, sawdust, etc.), and almost any organic substances can be used as a raw material for producing biogas.

In addition, biogas plants can be used in country houses and cottages, even if such farms do not have a farming focus. The household waste of any farm will be enough to provide raw materials for an individual biogas plant, and if the farm is not fully provided with thermal and electrical energy, then at least reduce the cost of purchasing such energy. In addition, in addition to household waste, any country farm also contains waste from the plot (weeds, branch cuttings, and so on). Well, you can even provide a kitchen stove with flammable gas using a mini-biogas installation in a country house.

Principle of biogas production

Biogas is produced by anaerobic (that is, without oxygen) fermentation of biomass, which is provided by special bacteria. Three types of bacteria are involved in the process: hydrolytic, acid-forming and methane-forming.

A biogas plant consists of several parts (containers). First, the raw material enters a preliminary container, where it is thoroughly mixed and crushed (in the case of the solid fraction) to a homogeneous mass. Then the crushed raw material enters the reactor (a container where the biomass is directly fermented).

The reactor is usually made of reinforced concrete, which is acid-resistant. This container is completely sealed. In order to speed up the fermentation process, the liquid in the container is heated and stirred. Most often, a cogeneration unit is used to heat the reactor - in such an installation it is necessary to cool the heat and power generator, and the removed heat enters the reactor. Heat can also come from a special hot water boiler.

After the fermentation process is completed, the produced gas from the reactor enters the gas holder, where the pressure is equalized, and then the biogas enters the heat and power generator (gas or diesel-gas), as a result of which thermal or electrical energy is produced.

In addition to biogas, a solid fraction—organic fertilizers—settles in the reactor, which can then be used in the fields. Liquid fertilizers are also obtained from the reactor after gas is released. Both liquid and solid fertilizers are concentrated and are actively used in agriculture.

Industrial biogas plants have automatic control. Automation is responsible for the flow of raw materials into the installation, and for mixing, controls the temperature, the operation of the generator, and so on. Also, such installations are equipped with emergency flare devices - in case the engine stops, then the gas is simply burned. In addition, industrial biogas plants are often equipped with a line for packaging liquid fertilizers; in this case, the fertilizers are bottled in small (up to 1 liter) bottles.

Individual biogas plant

The operating principle of an individual biogas plant is the same as that of an industrial one. True, mini-installations are rarely equipped with automatic devices for mixing the substrate and other automation - due to the significant increase in the cost of a household installation with such equipment. Most often, these installations only have devices for controlling temperature, generator operation, and so on, and all maintenance of the mini-biogas plant is carried out manually.

Household biogas plants are used mainly for the production of combustible gas for kitchen needs, if the farm does not have livestock or crop production. However, there is an increasing tendency to use mini-installations to provide country houses and cottages with a complete energy complex, that is, not only “kitchen” gas, but also thermal and electrical energy. Moreover, this no longer depends on the presence of large or small livestock on the farm; raw materials for home biogas plants are simply purchased from the nearest farm. This can be either manure or waste from wood processing industries.

DIY biogas plant

The construction of biogas plants, even mini ones, for domestic needs, is not cheap. And, although the payback period for such equipment is relatively short (5-7 years), not every owner is ready or has the opportunity to invest the required amount. Yes, the advantages are obvious: in a short time, with the help of a mini-biogas plant, you can gain almost complete autonomy from purchased energy sources, transfer your farm to self-sufficiency, and even have free fertilizers as additional bonuses. However, you need to pay money today, and the benefits will only appear in a few years. Therefore, many owners of country houses and cottages are wondering: how to make a biogas plant yourself?

A mini biogas plant is not that complicated, and its construction is quite manageable. This saves a significant amount. In addition, there are projects for biogas plants that use improvised means and materials (for example, with a bell reactor, and the bell can be made of rubber, and so on). That is, homemade installations for the production of biogas mean acquiring the desired bonuses for minimal money.

When building a biogas plant, it is necessary to make an accurate calculation of what its productivity should be. To do this, you should take into account all the desired consumers of biogas (for example, a cooker, automotive equipment, and so on). If biogas is planned to be used to produce electrical and/or thermal energy, then the calculation must include all energy consumers. Based on the calculation, a biogas plant project is created.

Homemade biogas production plants are widely available on the Internet. You can find sample calculations, a drawing of the device, and a detailed description. A huge selection of devices will allow you to create both a complex installation with several chambers and a simplified version (for example, such a simple device as a cesspool covered with a rubber bell with a device for venting gas). Anyone can choose a home-made installation in accordance with their desires, capabilities and skills. Descriptions accompanied by step-by-step photographs or videos are especially useful in this case.

Making a biogas plant with your own hands allows you to save up to 50% of the cost of the device, which significantly speeds up the payback of the equipment. In addition, making the simplest installation to begin with allows you to assess the need for such equipment in the household, as well as invest money gradually, which for many is much easier than paying the entire required amount at once.

How does a biogas plant work?

Many household owners are concerned about how to reduce costs for home heating, cooking and electricity supply. Some of them have already built biogas plants with their own hands and have partially or completely isolated themselves from energy suppliers. It turns out that getting almost free fuel in a private household is not very difficult.

What is biogas and how can it be used?

Owners of homestead farms know: by putting any plant material, bird droppings and manure in a heap, over time you can obtain valuable organic fertilizer. But few of them know that biomass does not decompose on its own, but under the influence of various bacteria.

By processing the biological substrate, these tiny microorganisms release waste products, including a gas mixture. Most of it (about 70%) is methane - the same gas that burns in the burners of household stoves and heating boilers.

The idea of ​​using such eco-fuels for various economic needs is not new. Devices for its extraction were used in ancient China. Soviet innovators also explored the possibility of using biogas in the 60s of the last century. But the technology experienced a real revival in the early 2000s. Currently, biogas plants are actively used in Europe and the USA for heating homes and other needs.

How does a biogas plant work?

The operating principle of the biogas production device is quite simple:

• biomass diluted with water is loaded into a sealed container, where it begins to “ferment” and release gases;
• the contents of the tank are regularly updated - the raw materials processed by bacteria are drained and fresh ones are added (on average about 5-10% daily);
• The gas accumulated in the upper part of the tank is supplied through a special tube to the gas collector, and then to household appliances.

Diagram of a biogas plant.

What raw materials are suitable for bioreactor?

Installations for producing biogas are profitable only where there is a daily replenishment of fresh organic matter - manure or droppings of livestock and poultry. You can also add chopped grass, tops, leaves and household waste (in particular, vegetable peelings) into the bioreactor.

The efficiency of the installation largely depends on the type of raw material being loaded. It has been proven that, with the same mass, the highest biogas yield is obtained from pig manure and turkey droppings. In turn, cow excrement and silage waste produce less gas for the same load.

Use of bio-raw materials for home heating.

What cannot be used in a biogas plant?

There are factors that can significantly reduce the activity of anaerobic bacteria, or even completely stop the process of biogas production. Raw materials containing:

• antibiotics;
• mold;
• synthetic detergents, solvents and other “chemicals”;
• resins (including sawdust from coniferous trees).

It is ineffective to use already rotting manure - only fresh or pre-dried waste can be loaded. Also, the raw materials should not be allowed to become waterlogged - an indicator of 95% is already considered critical. However, a small amount of clean water still needs to be added to the biomass in order to facilitate its loading and speed up the fermentation process. Manure and waste are diluted to the consistency of thin semolina porridge.

Biogas plant for home

Today, industry is already producing installations for producing biogas on an industrial scale. Their acquisition and installation is expensive; such equipment in private households pays for itself no sooner than in 7-10 years, provided that large volumes of organic matter are used for processing. Experience shows that, if desired, a skilled owner can build a small biogas plant for a private home with his own hands, and from the most affordable materials.

Preparing the processing bunker

First of all, you will need a hermetically sealed cylindrical container. You can, of course, use large pots or boils, but their small volume will not allow achieving sufficient gas production. Therefore, for these purposes, plastic barrels with a volume of 1 m³ to 10 m³ are most often used.

You can make one yourself. PVC sheets are commercially available; with sufficient strength and resistance to aggressive environments, they can be easily welded into the structure of the desired configuration. A metal barrel of sufficient volume can also be used as a bunker. True, you will have to carry out anti-corrosion measures - cover it inside and outside with moisture-resistant paint. If the tank is made of stainless steel, this is not necessary.

Gas exhaust system

The gas outlet pipe is mounted in the upper part of the barrel (usually in the lid) - this is where it accumulates, according to the laws of physics. Through a connected pipe, biogas is supplied to the water seal, then to the storage tank (optionally, using a compressor into a cylinder) and to household appliances. It is also recommended to install a release valve next to the gas outlet - if the pressure inside the tank becomes too high, it will release excess gas.

Raw material supply and unloading system

To ensure continuous production of the gas mixture, the bacteria in the substrate must be constantly (daily) “fed”, that is, fresh manure or other organic matter must be added. In turn, already processed raw materials from the bunker must be removed so that they do not take up useful space in the bioreactor.

To do this, two holes are made in the barrel - one (for unloading) almost near the bottom, the other (for loading) higher. Pipes with a diameter of at least 300 mm are welded (soldered, glued) into them. The loading pipeline is directed upward and equipped with a funnel, and the drain is arranged so that it is convenient to collect the processed slurry (it can later be used as fertilizer). The joints are sealed.

Heating system

Thermal insulation of the bunker.

If the bioreactor is installed outdoors or in an unheated room (which is necessary for safety reasons), then it must be provided with thermal insulation and heating of the substrate. The first condition is achieved by “wrapping” the barrel with any insulating material or by deepening it into the ground.

As for heating, you can consider a variety of options. Some craftsmen install pipes inside through which water circulates from the heating system and install them along the walls of the barrel in the form of a coil. Others place the reactor in a larger tank with water inside, heated by electric heaters. The first option is more convenient and much more economical.

To optimize the operation of the reactor, it is necessary to maintain the temperature of its contents at a certain level (at least 38⁰C). But if it rises above 55⁰C, then the gas-forming bacteria will simply “cook” and the fermentation process will stop.

Mixing system

As practice shows, in designs, a manual stirrer of any configuration significantly increases the efficiency of the bioreactor. The axis to which the “mixer” blades are welded (screwed) is removed through the barrel lid. The gate handle is then placed on it, and the hole is carefully sealed. However, home craftsmen do not always equip fermenters with such devices.

Biogas production

After the installation is ready, biomass diluted with water in a ratio of approximately 2:3 is loaded into it. Large waste must be crushed - the maximum fraction size should not exceed 10 mm. Then the lid is closed - all you have to do is wait for the mixture to begin to “ferment” and release biogas. Under optimal conditions, the first supply of fuel is observed several days after loading.

The fact that the gas has “started” can be judged by the characteristic gurgling sound in the water seal. At the same time, the barrel should be checked for leaks. This is done using a regular soap solution - it is applied to all joints and observed to see if bubbles appear.

The first update of bio-raw materials should be carried out in about two weeks. After the biomass is poured into the funnel, the same volume of waste organic matter will pour out of the outlet pipe. Then this procedure is performed daily or every two days.

How long does the resulting biogas last?

In a small farm, a biogas plant will not be an absolute alternative to natural gas and other available energy sources. For example, using a device with a capacity of 1 m³, you can only get fuel for a couple of hours of cooking for a small family.

But with a 5 m³ bioreactor it is already possible to heat a room with an area of ​​50 m², but its operation will need to be maintained by daily loading of raw materials weighing at least 300 kg. To do this, you need to have about ten pigs, five cows and a couple of dozen chickens on the farm.

Craftsmen who have managed to independently make working biogas plants share videos with master classes on the Internet: