Homemade biogas. Making biogas plants with your own hands

You can mount small installations at home. To digress, I will say that getting biogas with your own hands is not some kind of new invention. Even in ancient times, biogas at home was actively obtained in China. This country is still the leader in terms of the number of biogas plants. But here how to make a biogas plant with your own hands, what is needed for this, how much it will cost - I will try to tell all this in this and subsequent articles.

Preliminary calculation of biogas plant

Before proceeding with the purchase or self-assembly of a biogas plant, it is necessary to adequately assess the availability of raw materials, their type, quality and the possibility of an uninterrupted supply. Not every raw material is suitable for biogas production. Raw materials that do not fit:

• raw materials with a high content of lignin;
• raw materials containing sawdust of coniferous trees (with the presence of resins)
• with humidity exceeding 94%
• rotting manure, as well as raw materials with mold or synthetic detergents.

If the raw material is suitable for processing, then you can proceed to determine the volume of the bioreactor. The total volume of raw materials for the mesophilic mode (biomass temperature ranges from 25-40 degrees, the most common mode) does not exceed 2/3 of the reactor volume. The daily dose is not more than 10% of the total loaded raw materials.

Any raw material is characterized by three important parameters:

• density;
• ash content;
• humidity.

The last two parameters are determined from statistical tables. The raw material is diluted with water taking into account the achievement of 80-92% humidity. The ratio of the amount of water and raw materials can vary from 1:3 to 2:1. This is done to give the substrate the required fluidity. Those. to ensure the passage of the substrate through the pipes and the possibility of mixing it. For small biogas plants, the density of the substrate can be taken equal to the density of water.

Let's try to determine the volume of the reactor using an example.

Let's say the farm has 10 cattle, 20 pigs and 35 chickens. Excrement comes out per day: 55 kg from 1 cattle, from 1 pig - 4.5 kg and 0.17 kg from chicken. The volume of daily waste will be: 10x55 + 20x4.5 + 0.17x35 = 550 + 90 + 5.95 = 645.95 kg. Round up to 646 kg. The moisture content of pig and cattle excrement is 86%, and that of chicken manure is 75%. To achieve 85% moisture content in chicken manure, add 3.9 liters of water (about 4 kg).

It turns out that the daily dose of loading of raw materials will be about 650 kg. Full load of the reactor: OS=10x0.65=6.5 tons, and reactor volume OP=1.5x6.5=9.75 m³. Those. we need a reactor with a volume of 10 m³.

Biogas yield calculation

Table for calculating the yield of biogas depending on the type of raw material.

If we take the same example, then multiplying the weight of each type of raw material by the corresponding tabular data and summing up all three components, we get a biogas yield of approximately 27-36.5 m³ per day.

In order to navigate the required amount of biogas, I will say that an average family of 4 people will need 1.8-3.6 m³ for cooking. To heat a room of 100 m² - 20 m³ of biogas per day.

Installation and fabrication of the reactor

A metal tank, a plastic container can be used as a reactor, or it can be built of brick, concrete. Some sources say that the preferred shape is a cylinder, but in square structures built of stone or brick, cracks form due to the pressure of raw materials. Regardless of the shape, material and installation location, the reactor must:

• be water and gas tight. Mixing of air with gas should not take place in the reactor. Between the cover and the body there must be a gasket made of sealed material;
• be thermally insulated;
• withstand all loads (gas pressure, weight, etc.);
• have a hatch for repair work.

The installation and selection of the reactor shape is made for each farm individually.

Fabrication theme do-it-yourself biogas plant very extensive. Therefore, I will focus on this in this article. In the next article, we will talk about the choice of other elements of a biogas plant, prices and where it can be purchased.

Anyone can create biogas on their own. This does not require special knowledge and special skills in the field of renewable energy sources. If each person thinks about the world around him, the situation with the ecology on Earth will improve significantly.

Manure gas is a reality. It can indeed be obtained from manure, which in one way or another fertilizes the earth. But you can put it into circulation and get real gas.

To get gas from manure with your own hands at home, a farm biogas plant is used. You can extract natural gas using a digester right on the farm. This is how many farmers do it. For this, you do not need to purchase special fuel. Enough natural raw materials.

The bioreactor should include from 1 to 8-10 cubic meters. waste of private production, chicken manure. The production and processing of raw materials on a device with such a volume will be able to process more than 50 kg of manure. To make a biogas plant, you should find the drawings according to which the equipment is made, and you also need a diagram.

The operation of the installation is carried out in several stages:

A home-made installation will allow you to get gas from manure in a matter of time. It can be assembled independently, having diagrams and drawings. For the heat generator, you can choose boilers for heating water. To collect gas on the site you need a gas tank. It collects and stores gas.

Remember that impurities and debris in the tank should be cleaned from time to time.

You can get gas from manure using a biogas plant. It can be designed by hand. Determine the volume of processed raw materials, choose a suitable container in which the raw materials will be processed and mixed - this is how the production of gas saturated with methane in biofuel occurs.

Making biogas at home

There is a stereotype that biogas can only be obtained at specialized industries and farms. However, it is not. Today you can make biogas at home.

Biogas is a collection of various gases that are created by the decomposition of organic matter. It is worth knowing that biogas is flammable. It ignites easily with a pure flame.

We note the advantages of a biogas plant at home:

1. Obtaining biogas without expensive equipment;
2. Using your ;
3. Natural and free raw materials in the form of manure or plants;
4. Caring for the environment.

Having a biogas plant at home is a profitable business for the owner of a summer cottage. To make such an installation, a small amount of funds is needed: two barrels of 200 liters each, a barrel of 50 liters, sewer pipes, a gas hose and a tap.

As you can see, to do the installation yourself, you don’t even need to buy additional tools. Barrels, faucet, hoses and pipes can almost always be found on the farm of cottage owners. The gas generator is a concern for the environment, as well as your opportunity to use an alternative source of energy and fuel.

Why do you need a biogas plant for farming

Some farmers, summer residents, owners of private houses do not see the need to make a biogas plant. At first glance, it is. But then, when the owners see all the benefits, the question of the need for such an installation disappears.

The first obvious reason to make a biogas plant on a farm is to get electricity, heating, which will allow you to pay less for electricity.

Using your energy is cheaper than paying for its supply to the farm.

Another main reason for the need to create an installation is the organization of a complete cycle of non-waste production. As a raw material for the device, we use manure or droppings. After processing, we get new gas.

The third reason in favor of a biogas plant is the efficient processing and environmental impact.

3 advantages of a biogas plant:

• Getting energy to keep the family farm running;
• Organization of the completed cycle;
• Efficient use of raw materials.

Having an installation on a farm is an indicator of your efficiency and concern for the world around you. Biogenerators save a huge amount of money by making production zero waste, efficient allocation of resources and raw materials, but also your complete self-sufficiency.

A heat pump is easy to assemble with your own hands from old home equipment. The whole process is described in the following article:

Question for an efficient economy: how to get methane correctly

Methane is the main component of biogas. Biogas itself is a mixture of various gases. Among them, methane is the most important.

Let's highlight the factors that affect the production of methane:

• Environment;
• Quality raw materials;
• The frequency of mixing of raw materials in the installation tank.

Mix the raw materials in the container with a pitchfork and at least once a day, ideally - six times.

The production of methane is directly related to the production of biogas. The better you treat the process of obtaining biogas, the better you will get biogas at the output. To do this, you need to use only high-quality raw materials, monitor the place where the installation is located, and mix the contents of the tank. Then you will get methane correctly.

DIY biogas plant (video)

There are more and more supporters of preserving the environment in its original form. Without emissions and environmental pollution. Biogas plants solve this problem. In addition, the owner of the biogas plant personally receives direct monetary benefits from its use.

With rising global energy prices, many people in rural areas are looking at alternative methods to replace them. Some inventors have installed wind turbines to provide their homes with electricity. But what about gas? After all, the lion's share of heating costs goes to pay for the consumed gas. People began to think about how to get gas on their own. For this purpose, a bioreactor operating on agricultural waste was created. For a simple villager, this is a very expensive installation. But some inventors claim that almost every owner of his yard can make a bioreactor with his own hands.

The principle of operation of the bioreactor

The bioreactor works on organic waste, therefore, for its continuous operation, the constant presence of manure and other agricultural waste is necessary. The biogas produced by the plant is a biologically clean fuel, and in terms of its performance it is similar to natural gas.

The work of the bioreactor is to process organic waste into gas and fertilizer. To do this, they are loaded into a bioreactor tank, where anaerobic bacteria process the biomass. To obtain proper fermentation, air must not enter the tank. The processing time depends on the amount of waste loaded. The emitted gas consists of methane 60%, and carbon dioxide - 35%. Other impurities make up 5%. The resulting gas is purified and then ready for use in household appliances.

Note! Recycled raw materials are removed from the tank and used as fertilizer in agriculture, and new waste is loaded in its place.

The design of the simplest bioreactor

The simplest device that you can build with your own hands consists of a reactor for processing, a loading tank, an entrance hatch, a hatch for collecting waste waste, a water seal, and a gas outlet pipe. For a better idea, there is a diagram of a bioreactor in a simple design.

The bioreactor is made of reinforced concrete or a metal container and installed in the selected area of ​​the yard. The most important thing is that the installation is completely sealed. The size of the tank depends on the constant amount of waste for processing, which is loaded at 2/3 of its size. For reference: 100 m 3 of gas is obtained from 1 ton of waste during processing. Based on these calculations, it is not advisable to install a small capacity. After all, the amount of gas produced depends on the amount of waste loaded for processing. One of the main devices on the tank is the waste selection hatch, which must be airtight.

Note! Waste waste must be constantly unloaded. So that the hatch is not deformed from frequent opening, and there is no gas leakage, it is necessary to provide for its reliable design.

Particular attention should be paid to the construction of the reservoir. The walls and bottom must have a solid concrete base. During pouring, reinforcement must be performed. After the solution has hardened, the surface is treated with waterproofing agents. The top of the tank is made of refractory bricks laid on a metal frame.

Biomass heating

The constant operation of the reactor depends on the vital activity of bacteria causing the fermentation of biomass. In the cold mass, they are in sleep mode. It is worth warming it up to the desired temperature and the bacteria will resume their work. The optimum fermentation temperature is from +38 º C. In warm regions, the outside air temperature is sufficient to operate the reactor without heating. And for cold regions, you will have to install a heating system. A heating coil installed under the tank can cope with this problem. It is connected to the heating system and taps (or a thermostat) regulate the circulation of hot water to maintain the desired temperature.

Note! Just as an option, you can install a coil with electric heaters. They are connected to an automation system that regulates the heating temperature. To do this, you can use the usual automation from hot water boilers.

Mixer for bioreactor

During the operation of the reactor, for better bacterial activity, the raw material must be periodically mixed. This role can be performed by a device in the form of a mixer. Its blades are inside the tank, and the shaft goes out. The mixer is driven by an electric motor. At the exit of the shaft, there should be seals that maintain the tightness of the chamber.

Note! In some cases, a sealed motor is installed directly in the tank.

Getting gas

The gas produced during the reaction exits through an exhaust pipe connected to the top cover. Through a pipe, it is fed into a water seal, which will prevent air from entering the gas. The gas purified in the hydraulic seal with water is sent to the gas tank for further transportation to the consumer. To improve the system, two gas tanks can be installed. In this system, condensate will settle in the first tank, and gas under pressure will be pumped into the second tank. To control the gas pressure, it is necessary to install a pressure gauge and a release valve. Excessive gas pressure will open the valve and bleed the excess out.

A biogas plant for the home will save energy costs. Such a unit can be made independently.

The cost of components is quite affordable, and the produced gas can be used for various purposes - heating, cooking, etc.

Biogas technology

The principle of operation of a biogas plant is based on the fermentation of the biosubstrate. It decomposes under the influence of hydrolytic, methane- and acid-forming microorganisms. Combustible gas is produced containing a high volume of methane.

Gas is actually not inferior to natural, used in everyday life and industry. There are ready-made installations. But, their cost is quite high, the payback period reaches 10 years.

For the operation of a biogas plant, it is possible to use available raw materials - recyclable waste. They are processed as follows:

• Raw materials ferment under the influence of microorganisms.
• Combustible gases are emitted - methane, carbon dioxide and others. The main volume is represented by methane
• The gases are purified and enter the gas tank, where they are stored until they are used directly.

Gas can be used in the same way as natural gas. It can be used as fuel for boilers, furnaces, gas stoves, etc. Waste raw materials must be removed from the installation in a timely manner. Waste can be used as fertilizer.

Advantages and disadvantages

The main advantages of the installation include:

• efficient waste disposal;
• biomass is constantly renewed through agricultural activities;
• relatively low content of carbon dioxide;
• a small amount of sulfur emitted;
• stability, uninterrupted operation, independent of external factors;
• the possibility of simultaneous operation of several units;
• economic benefit, especially for people who are actively involved in agricultural activities.

The disadvantages include a slight environmental pollution. There may also be difficulties with the supply of raw materials.

Preparation of a pit for a bioreactor

The device of the biogas plant assumes its underground location. It is necessary to prepare a hole of the required volume. Its walls can be hermetically reinforced and finished with plastic, polymer rings or concrete.

The intensity of processing of raw materials depends on the tightness. Ideally, you should purchase factory-made polymer rings with a dry bottom. This is a more expensive solution, but additional sealing can be avoided.

Polymeric materials are resistant to moisture and aggressive environments. They do not need to be repaired, and if damaged, they can be quickly replaced.

Drainage for gas

Purchasing and installing specialized agitators is not the most cost-effective option. To save money, you can make gas drainage. These are vertical plastic sewer pipes with a large number of holes.

Drainage can also be made from steel pipes, which are highly resistant to negative influences. But, plastic is more practical because of the anti-corrosion properties.

In the photo of a home-made biogas plant, you can clearly see this design and the features of its construction.

The length of the drain pipes should be selected according to the filling depth of the bioreactor. The top of the pipes must protrude above this level.

Insulation layer

After the manufacture of the bioreactor, it can be immediately filled with raw materials. Biomass must be covered with foil. This is necessary to ensure a slight gas pressure during the fermentation process.

Once the dome is fabricated, this ensures efficient biogas flow through the system.

Installation of the dome and pipes

We will analyze directly how to make the simplest biogas plant with your own hands. In fact, all the preparatory work has been completed, the bioreactor has been built and filled with biomass.

It remains to mount the dome section. A pipe is mounted at the top of the dome, which provides gas removal. Through it, biogas is fed into the gas tank.

The reactor also has free space in which a certain volume of gas will actually be stored. But, this cannot ensure the safety of operation.

It is necessary to constantly consume gas, otherwise the pressure will reach the boundary mark, and an explosion will occur. Therefore, a gas tank must be mounted. If necessary, gas should be filled with suitable containers to avoid pressure build-up.

The bioreactor must be hermetically sealed. Otherwise, the gas will simply escape into the atmosphere. To prevent air from entering the gas mixture, the system should be equipped with a water seal. It will also provide gas purification.

In the design, it is imperative to make a release valve. It should automatically operate when the permissible pressure level is exceeded.

How to heat the bioreactor?

Bacteria generating gas are constantly present in the substrate. But in order for them to multiply intensively, the temperature of the environment must be at least 38 ° C.

Therefore, the bioreactor must be heated, especially in winter. You can install a coil connected to a domestic heating system.

Another way is to install electric heating elements. But, a more cost-effective solution is to connect to the heating system.

The easiest option is to arrange heating from below by laying a heating pipe. However, the efficiency of such a heat exchanger will be relatively low.

A biogas plant may or may not be done underground. There are alternative methods. For example, it can be performed in a barrel, which will be located in a separate room.

You can also use, for example, a tank. This option will simplify heating, but requires sufficient space.

DIY biogas plant photo

Many household owners are concerned about how to cut home heating, cooking and electricity costs. Some of them have already built biogas plants with their own hands and partially or completely separated 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 household plots know that by putting together any vegetable raw materials, bird droppings and manure, after a while you can get valuable organic fertilizer. But few of them know that biomass does not decompose by itself, but under the influence of various bacteria.

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 household needs is not new. Devices for its extraction were used in ancient China. The possibility of using biogas was also explored by Soviet innovators in the 60s of the last century. But the technology experienced a real revival in the early 2000s. At the moment, biogas plants are actively used in Europe and the USA for heating houses and other needs.

How does a biogas plant work?

The principle of operation of the device for the production of biogas 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.

Which raw material is suitable for bioreactor?

Biogas plants are profitable only where there is a daily replenishment of fresh organic matter - manure or droppings from livestock and poultry. Also, crushed grass, tops, leaves and household waste (in particular, vegetable peelings) can be mixed into the bioreactor.

The efficiency of the installation largely depends on the type of feedstock. It has been proven that with the same mass, the largest biogas yield is obtained from pig manure and turkey manure. In turn, cow dung and silage produce less gas for the same load.

The 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. Do not allow raw materials containing:

• antibiotics;
• mold;
• synthetic detergents, solvents and other "chemistry";
• resins (including sawdust of coniferous trees).

It is inefficient to use already rotting manure - only fresh or pre-dried waste is to be loaded. Also, waterlogging of raw materials should not be allowed - an indicator of 95% is already considered critical. However, it is still necessary to add a small amount of pure water to the biomass in order to facilitate its loading and speed up the fermentation process. Dilute manure and waste to the consistency of thin semolina.

Biogas plant for home

Today, the industry is already producing plants for biogas production on an industrial scale. Their purchase and installation is expensive, such equipment in private households pays off no earlier 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 house with his own hands, and from the most affordable materials.

Preparing a processing bunker

First of all, you need a hermetically sealed cylindrical container. You can, of course, use large pots or boils, but their small volume does not allow sufficient gas production to be achieved. 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 are easily welded in the design of the desired configuration. A metal barrel of sufficient volume can also be used as a bunker. True, it will be necessary to carry out anti-corrosion measures - to cover it from the 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 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 a water seal, then to a storage tank (as an option, using a compressor into a cylinder) and to household appliances. It is also recommended to install a release valve near the gas outlet - if the pressure inside the tank becomes too high, it will release excess gas.

Feeding and unloading system of raw materials

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

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

heating system

Bunker insulation.

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 a recess in the ground.

As for heating, here you can consider a variety of options. Some craftsmen lead pipes inside, through which water from the heating system circulates and mount 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-producing bacteria will simply “cook” and the fermentation process will stop.

Mixing system

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

Biogas production

After the installation is ready, it is loaded with biomass, diluted with water in a ratio of approximately 2:3. In this case, large waste must be crushed - the maximum fraction size should not exceed 10 mm. Then the lid closes - it remains to wait for the mixture to begin to "ferment" and release biogas. Under optimal conditions, the first supply of fuel is observed a few days after loading.

The fact that the gas "went" can be judged by the characteristic gurgling in the water seal. At the same time, the barrel should be checked for leaks. This is done using an ordinary soapy solution - it is applied to all joints and observed to see if bubbles have appeared.

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 spent organics will pour out of the outlet pipe. Further, this procedure is performed daily or every two days.

How much biogas is produced?

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

But with a bioreactor of 5 m³ it is already possible to heat a room of 50 m², but its work will need to be supported by a daily load 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.

Masters who managed to independently make existing biogas plants share videos with master classes on the Internet: