Do-it-yourself home biogas plant. DIY biogas at home Home biogas plant

The growing popularity of alternative methods of obtaining heat and electricity has led to the desire of many owners of country houses and cottages to obtain a certain autonomy from external energy suppliers. Moreover, “purchased” energy shows a constant tendency to increase prices, and the maintenance of a country economy is getting more and more expensive every day. A biogas plant is an excellent alternative for external energy sources. At a minimum, it can provide the house with combustible gas for the stove, and with an increase in power (if there is enough of its 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 combustible 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. Thus, it is possible not only to make production waste-free, but also to significantly increase its profitability - due to independent energy production, 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, proved from his own experience that agricultural production, which independently utilizes waste using an appropriate device, fully meets its needs for heat and electricity, as well as combustible gas. In his quail farm, biogas is used for heating premises (both residential and utility and industrial), for generating electricity, in kitchen stoves, as well as for refueling vehicles - all cars of the Rashin farm run on biogas. In this case, the main raw material for the biogas plant is quail manure. At the output, in addition to biogas, organic fertilizer is also obtained, which also brings additional income to the farm.

Biogas plants like Vladimir Rashin's can significantly increase the profitability of any agricultural production. As a raw material for biogas production, not only manure can be used, but also various waste products from woodworking industries (bark, sawdust, and so on), and almost any organic matter.

In addition, biogas plants can also be used in country houses and cottages, even if such farms do not have a farming orientation. Household waste from 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 acquiring such energy. In addition, in addition to household waste, in any suburban economy there is also waste from a personal plot (weeds, cuttings of branches, and so on). Well, it is possible to provide a stove with combustible gas even with the help of a mini-biogas plant in country conditions.

The principle of obtaining biogas

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.

The biogas plant consists of several parts (tanks). First, the raw material enters the preliminary tank, where it is thoroughly mixed and crushed (in the case of a 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 acid-resistant reinforced concrete. This container is completely sealed. In order to speed up the fermentation process, the liquid in the container is heated and mixed. Most often, a cogeneration plant 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. Also, heat can come from a special hot water boiler.

After the fermentation process is completed, the generated 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 is deposited in the reactor - organic fertilizers, which can then be used in the fields. Liquid fertilizers are also obtained from the reactor - after the release of gas. 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 which case fertilizers are bottled into small (up to 1 liter) bottles.

Individual biogas plant

The principle of operation 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 a configuration. Most often, these plants have only temperature control devices, generator operation, and so on, and all maintenance of the mini-biogas plant is carried out manually.

Household biogas plants are mainly used for the production of combustible gas for kitchen needs, if the farm does not have a livestock or crop-growing orientation. However, there is an increasing trend towards the use of 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, it 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. It can be both manure and woodworking waste.

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 get 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 advantages will appear only in a few years. Therefore, many owners of country houses and cottages are wondering: how to make a biogas plant on their own?

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

When building a biogas plant, it is necessary to make an accurate calculation - what should be its performance. To do this, all desired consumers of biogas should be taken into account (for example, a cooker, automotive equipment, etc.). If biogas is planned to be used to generate electricity and/or heat energy, then the calculation should include all energy consumers. Based on the calculation, a biogas plant project is created.

Homemade biogas plants are widely represented on the Internet. You can find sample calculations, and a drawing of the device, and a detailed description. A huge selection of devices will make it possible to manufacture 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 gas outlet device). Everyone will be able to choose a home-made installation in accordance with their desires, capabilities and skills. Particularly useful in this case are descriptions accompanied by step-by-step photographs or videos.

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 equipment. In addition, making the simplest installation to start with allows you to assess the need for such equipment on the farm, as well as invest money gradually, which for many is much easier than paying the entire amount right away.

How does a biogas plant work?

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:

Mixing of raw materials;

Heating;

Isolation of biogas.

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.

One of the tasks that have to be solved in agriculture is the disposal of manure and plant waste. And this is a rather serious problem that requires constant attention. Recycling takes not only time and effort, but also a decent amount. Today there is at least one way to turn this headache into an income item: processing manure into biogas. The technology is based on the natural process of decomposition of manure and plant residues due to the bacteria contained in them. The whole task is to create special conditions for the most complete decomposition. These conditions are the lack of oxygen access and the optimum temperature (40-50 o C).

Everyone knows how manure is most often disposed of: piled up, then, after fermentation, taken out to the fields. In this case, the resulting gas is released into the atmosphere, and 40% of the nitrogen contained in the original substance and most of the phosphorus also fly there. The resulting fertilizer is far from perfect.

To obtain biogas, it is necessary that the process of manure decomposition takes place without access to oxygen, in a closed volume. In this case, both nitrogen and phosphorus remain in the residual product, and the gas accumulates in the upper part of the tank, from where it can be easily pumped out. Two sources of profit are obtained: gas directly and effective fertilizer. Moreover, the fertilizer is of the highest quality and is 99% safe: most of the pathogens and helminth eggs die, the weed seeds contained in manure lose their germination. There are even lines for packaging this residue.

The second prerequisite for the process of processing manure into biogas is maintaining the optimum temperature. Bacteria contained in the biomass are inactive at low temperatures. They begin to act at an ambient temperature of +30 o C. Moreover, two types of bacteria are contained in manure:

Thermophilic plants with temperatures from +43 o C to +52 o C are the most efficient: manure is processed in them for 3 days, up to 4.5 liters of biogas is obtained from 1 liter of bioreactor useful area (this is the maximum output). But maintaining a temperature of +50 o C requires significant energy costs, which is not profitable in every climate. Therefore, more often biogas plants operate at mesophilic temperatures. In this case, the processing time can be 12-30 days, the yield is approximately 2 liters of biogas per 1 liter of bioreactor volume.

The composition of the gas varies depending on the feedstock and processing conditions, but approximately it is as follows: methane - 50-70%, carbon dioxide - 30-50%, and also contains a small amount of hydrogen sulfide (less than 1%) and a very small amount of ammonia, hydrogen and nitrogen compounds. Depending on the design of the plant, biogas can contain a significant amount of water vapor, which will require dehydration (otherwise it simply will not burn). What the industrial installation looks like is shown in the video.

It can be said a whole gas production plant. But for a private courtyard or a small farm, such volumes are useless. The simplest biogas plant is easy to do with your own hands. But the question is: “Where to send biogas next?” The calorific value of the resulting gas is from 5340 kcal / m3 to 6230 kcal / m3 (6.21 - 7.24 kWh / m3). Therefore, it can be supplied to a gas boiler for heat generation (heating and hot water), or to an electricity generation plant, gas stove, etc. This is how Vladimir Rashin, the designer of a biogas plant, uses manure from his quail farm.

It turns out that having at least some more or less decent amount of livestock and poultry, you can fully meet the needs of your household in heat, gas and electricity. And if you install gas installations on cars, then fuel for the fleet. Given that the share of energy in the cost of production is 70-80%, you can only save on a bioreactor, and then earn a lot of money. Below is a screenshot of the economic calculation of the profitability of a biogas plant for a small farm (as of September 2014). You can’t call the economy small, but it’s definitely not large either. We apologize for the terminology - this is the author's style.

This is an approximate breakdown of the required costs and possible income. Schemes of self-made biogas plants

Schemes of self-made biogas plants

The simplest scheme of a biogas plant is a sealed container - a bioreactor, into which the prepared slurry is poured. Accordingly, there is a hatch for loading manure and a hatch for unloading processed raw materials.

The simplest scheme of a biogas plant without "bells and whistles"

The container is not completely filled with the substrate: 10-15% of the volume must remain free to collect gas. A gas pipe is built into the tank lid. Since the resulting gas contains a rather large amount of water vapor, it will not burn in this form. Therefore, it is necessary to pass it through a water seal for drainage. In this simple device, most of the water vapor will condense, and the gas will already burn well. Then it is desirable to purify the gas from non-combustible hydrogen sulfide, and only then it can be fed into the gas holder - a container for collecting gas. And from there it is already possible to breed to consumers: feed it to a boiler or a gas stove. How to make filters for a biogas plant with your own hands, see the video.

Large industrial installations are placed on the surface. And this, in principle, is understandable - the volume of land work is too large. But in small farms, the bunker bowl is buried in the ground. This, firstly, allows you to reduce the cost of maintaining the required temperature, and secondly, in a private courtyard, there are already enough devices.

The container can be taken ready-made, or made of brick, concrete, etc. in a dug pit. But in this case, you will have to take care of the air tightness and obstruction: the process is anaerobic - without air access, therefore it is necessary to create a layer impermeable to oxygen. The construction turns out to be multi-layered and the manufacture of such a bunker is a long and costly process. Therefore, it is cheaper and easier to bury the finished container. Previously, these were necessarily metal barrels, often stainless steel. Today, with the advent of PVC containers on the market, you can use them. They are chemically neutral, have low thermal conductivity, long service life, and are several times cheaper than stainless steel.

But the biogas plant described above will have low productivity. To activate the processing process, active mixing of the mass in the hopper is necessary. Otherwise, a crust is formed on the surface or in the thickness of the substrate, which slows down the decomposition process, and less gas is obtained at the outlet. Mixing is carried out in any available way. For example, as shown in the video. In this case, any drive can be made.

There is another way of mixing the layers, but non-mechanical - barbitation: the gas produced under pressure is fed into the lower part of the manure tank. Rising up, gas bubbles will break the crust. Since the same biogas is supplied, there will be no changes in processing conditions. Also, this gas cannot be considered an expense - it will again fall into the gas tank.

As mentioned above, high temperatures are required for good performance. In order not to spend too much money on maintaining this temperature, it is necessary to take care of the insulation. What type of heat insulator to choose, of course, is your business, but today the most optimal one is polystyrene foam. It is not afraid of water, is not affected by fungi and rodents, has a long service life and excellent thermal insulation performance.

The shape of the bioreactor can be different, but the most common is cylindrical. It is not ideal in terms of the complexity of mixing the substrate, but is used more often because people have accumulated a lot of experience in building such containers. And if such a cylinder is divided by a partition, then they can be used as two separate tanks in which the process is shifted in time. At the same time, a heating element can be built into the partition, thus solving the problem of maintaining the temperature in two chambers at once.

In the simplest version, home-made biogas plants are a rectangular pit, the walls of which are made of concrete, and treated with a layer of fiberglass and polyester resin for tightness. This container comes with a lid. It is extremely inconvenient in operation: it is difficult to implement heating, mixing and removal of the fermented mass, it is impossible to achieve complete processing and high efficiency.

The situation is slightly better with trench biogas manure processing plants. They have beveled edges, which makes it easier to load fresh manure. If you make the bottom sloped, then the fermented mass will move by gravity in one direction and it will be easier to select it. In such installations, it is necessary to provide thermal insulation not only for walls, but also for covers. Such a biogas plant with your own hands is easy to implement. But full processing and the maximum amount of gas in it cannot be achieved. Even when heated.

The basic technical issues have been dealt with and you now know several ways to build a manure biogas plant. Remained technological nuances.

What can be recycled and how to achieve good results

In the manure of any animal there are organisms necessary for its processing. More than a thousand different microorganisms have been found to be involved in the digestion process and gas generation. The most important role is played by methane-formers. It is also believed that all these microorganisms are found in optimal proportions in cattle manure. In any case, when processing this type of waste in combination with plant mass, the largest amount of biogas is released. The table shows averaged data for the most common types of agricultural waste. Please note that this amount of gas output can be obtained under ideal conditions.

For good productivity, it is necessary to maintain a certain humidity of the substrate: 85-90%. But water must be used that does not contain foreign chemicals. Solvents, antibiotics, detergents, etc. negatively affect the processes. Also, for the normal course of the process, the slurry should not contain large fragments. The maximum size of the fragments: 1 * 2 cm, smaller ones are better. Therefore, if you plan to add herbal ingredients, then you need to grind them.

It is important for normal processing in the substrate to maintain an optimal pH level: within 6.7-7.6. Usually the medium has normal acidity, and only occasionally acid-forming bacteria develop faster than methane-forming ones. Then the environment becomes acidic, gas production decreases. To achieve the optimal value, ordinary lime or soda is added to the substrate.

Now a little about the time it takes to process manure. In general, the time depends on the created conditions, but the first gas can begin to flow already on the third day after the start of fermentation. The most active gas formation occurs during the decomposition of manure by 30-33%. To be able to navigate in time, let's say that after two weeks the substrate decomposes by 20-25%. That is, optimal processing should last a month. In this case, the fertilizer is of the highest quality.

Calculation of the volume of the bunker for processing

For small farms, the optimal setting is permanent action - this is when fresh manure is supplied in small portions daily and removed in the same portions. In order for the process not to be disturbed, the share of the daily load should not exceed 5% of the processed volume.

Home-made installations for the processing of manure into biogas are not the pinnacle of perfection, but they are quite effective

Based on this, you can easily determine the required tank volume for a homemade biogas plant. You need to multiply the daily volume of manure from your farm (already diluted with a moisture content of 85-90%) by 20 (this is for mesophilic temperatures, for thermophilic temperatures you will have to multiply by 30). Another 15-20% must be added to the figure obtained - free space for collecting biogas under the dome. You know the main parameter. All further costs and parameters of the system depend on which scheme of the biogas plant is chosen for implementation and how you will do everything. It is quite possible to get by with improvised materials, or you can order a turnkey installation. Factory developments will cost from 1.5 million euros, installations from the Kulibins will be cheaper.

Legal registration

The installation will have to be coordinated with the SES, gas inspection and firefighters. You will need:

• Technological scheme of the installation.
• Layout plan for equipment and components with reference to the installation itself, the installation site of the thermal unit, the location of pipelines and power lines, and the connection of the pump. Lightning rod and access roads should be marked on the diagram.
• If the unit is to be located indoors, a ventilation plan will also be required, which will ensure at least eight exchanges of the total air in the room.

As you can see, bureaucracy is indispensable here.

Finally, a little about the performance of the installation. On average, a biogas plant produces a volume of gas per day that is twice the useful volume of the reservoir. That is, 40 m 3 of slurry will give 80 m 3 of gas per day. Approximately 30% will be spent on ensuring the process itself (the main expense item is heating). Those. at the output you will receive 56 m 3 of biogas per day. To cover the needs of a family of three and to heat a medium-sized house, according to statistics, 10 m 3 is required. In the net balance you have 46 m 3 per day. And this is with a small installation.

Results

By investing some money in the construction of a biogas plant (do it yourself or on a turnkey basis), you will not only provide for your own needs and needs for heat and gas, but also be able to sell gas, as well as high-quality fertilizers resulting from processing.

The topic of alternative fuels has been relevant for several decades. Biogas is a natural source of fuel that you can generate and use on your own, especially if you have livestock.

What it is

The composition of biogas is similar to that produced on an industrial scale. Stages of biogas production:

1. A bioreactor is a container in which the biological mass is processed by anaerobic bacteria in a vacuum.
2. After some time, a gas is released, consisting of methane, carbon dioxide, hydrogen sulfide and other gaseous substances.
3. This gas is purified and removed from the reactor.
4. Processed biomass is an excellent fertilizer that is removed from the reactor to enrich the fields.

Do-it-yourself biogas production at home is possible, provided that you live in a village and you have access to animal waste. It is a good fuel option for livestock farms and agricultural businesses.

The advantage of biogas is that it reduces methane emissions and provides a source of alternative energy. As a result of biomass processing, fertilizer is formed for vegetable gardens and fields, which is an additional advantage.

To make your own biogas, you need to build a bioreactor to process manure, bird droppings, and other organic waste. As raw materials are used:

• wastewater;
• straw;
• grass;
• river silt.

It is important to prevent chemical impurities from entering the reactor, as they interfere with the reprocessing process.

Use cases

The processing of manure into biogas makes it possible to obtain electrical, thermal and mechanical energy. This fuel is used on an industrial scale or in private homes. It is used for:

• heating;
• lighting;
• water heating;
• operation of internal combustion engines.

With the help of a bioreactor, you can create your own energy base to provide a private home or agricultural production.

Biogas thermal power plants are an alternative way to heat a personal subsidiary farm or a small village. Organic waste can be converted into electricity, which is much cheaper than taking it to the site and paying utility bills. Biogas can be used for cooking on gas stoves. The great advantage of biofuels is that it is an inexhaustible, renewable source of energy.

Biofuel efficiency

Biogas from litter and manure is colorless and odorless. It gives as much heat as natural gas. One cubic meter of biogas provides as much energy as 1.5 kg of coal.

Most often, farms do not dispose of waste from livestock, but store it in one area. As a result, methane is released into the atmosphere, manure loses its properties as a fertilizer. Timely processed waste will bring much more benefits to the farm.

Calculating the efficiency of manure disposal in this way is easy. The average cow gives 30-40 kg of manure per day. From this mass, 1.5 cubic meters of gas is obtained. From this amount, electricity is generated 3 kW / h.

How to build a biomaterial reactor

Bioreactors are containers made of concrete with holes for the removal of raw materials. Before construction, you need to choose a place on the site. The size of the reactor depends on the amount of biomass you have daily. It should fill the container by 2/3.

If there is little biomass, instead of a concrete container, you can take an iron, for example, an ordinary barrel. But it must be strong, with high-quality welds.

The amount of gas produced directly depends on the volume of raw materials. In a small container, it will turn out a little. To get 100 cubic meters of biogas, you need to process a ton of biological mass.

To increase the strength of the installation, it is usually buried in the ground. The reactor must have an inlet pipe for loading biomass and an outlet for removing spent material. There must be a hole in the top of the tank through which the biogas is discharged. It is better to close it with a water seal.

For a correct reaction, the container must be hermetically sealed, without air access. The water seal will ensure the timely removal of gases, which will prevent the explosion of the system.

Reactor for a large farm

A simple bioreactor scheme is suitable for small farms with 1-2 animals. If you own a farm, it is best to install an industrial reactor that can handle large amounts of fuel. It is best to involve special firms involved in the development of the project and installation of the system.

Industrial complexes consist of:

• Intermediate storage tanks;
• mixer plant;
• A small CHP plant that provides energy for heating buildings and greenhouses, as well as electricity;
• Tanks for fermented manure used as fertilizer.

The most effective option is the construction of one complex for several neighboring farms. The more biomaterial is processed, the more energy is obtained as a result.

Before receiving biogas, industrial installations must be coordinated with the sanitary and epidemiological station, fire and gas inspection. They are documented, there are special rules for the location of all elements.

How to calculate the reactor volume

The volume of the reactor depends on the amount of waste generated daily. Remember that the container only needs to be filled 2/3 for efficient fermentation. Also consider fermentation time, temperature and type of raw material.

Manure is best diluted with water before being sent to the reactor. It will take about 2 weeks to process manure at a temperature of 35-40 degrees. To calculate the volume, determine the initial volume of waste with water and add 25-30%. The volume of biomass should be the same every two weeks.

How to ensure biomass activity

For proper biomass fermentation, it is best to heat the mixture. In the southern regions, the air temperature contributes to the start of fermentation. If you live in the north or in the middle lane, you can connect additional heating elements.

To start the process, a temperature of 38 degrees is needed. There are several ways to provide it:

• Coil under the reactor, connected to the heating system;
• Heating elements inside the tank;
• Direct heating of the tank with electric heaters.

The biological mass already contains bacteria that are needed to produce biogas. They wake up and begin activity when the air temperature rises.

It is best to heat them with automatic heating systems. They turn on when cold mass enters the reactor and turn off automatically when the temperature reaches the desired value. Such systems are installed in water-heating boilers, they can be bought at gas equipment stores.

If you provide heating to 30-40 degrees, then it will take 12-30 days to process. It depends on the composition and volume of the mass. When heated to 50 degrees, bacterial activity increases, and processing takes 3-7 days. The disadvantage of such installations is the high cost of maintaining a high temperature. They are comparable to the amount of fuel received, so the system becomes inefficient.

Another way to activate anaerobic bacteria is biomass mixing. You can independently install the shafts in the boiler and bring the handle out to stir the mass if necessary. But it is much more convenient to design an automatic system that will mix the mass without your participation.

Proper gas venting

Biogas from manure is removed through the top cover of the reactor. During fermentation, it must be tightly closed. Usually a water seal is used. It controls the pressure in the system, with an increase in the cover rises, the release valve is activated. A weight is used as a counterweight. At the outlet, the gas is cleaned with water and flows further through the pipes. Purification with water is necessary to remove water vapor from the gas, otherwise it will not burn.

Before biogas can be converted into energy, it must be stored. It should be stored in a gas holder:

• It is made in the form of a dome and installed at the outlet of the reactor.
• Most often it is made of iron and covered with several layers of paint to prevent corrosion.
• In industrial complexes, the gas tank is a separate tank.

Another option for making a gas tank is to use a PVC bag. This elastic material stretches as the bag fills up. If necessary, it can store a large amount of biogas.

Underground Biofuel Plant

To save space, it is best to build underground installations. This is the easiest way to get biogas at home. To equip an underground bioreactor, you need to dig a hole and fill its walls and bottom with reinforced concrete.

On both sides of the container, holes are made for the inlet and outlet pipes. Moreover, the outlet pipe should be located at the base of the container for pumping out the waste mass. Its diameter is 7-10 cm. An inlet with a diameter of 25-30 cm is best located in the upper part.

From above, the installation is closed with brickwork and a gas holder is installed to receive biogas. At the outlet of the tank, you need to make a valve to regulate the pressure.

The biogas plant can be buried in the yard of a private house and connected to sewage and livestock waste. Processing reactors can fully cover the needs of the family in electricity and heating. An additional plus in obtaining fertilizer for the garden.

A do-it-yourself bioreactor is a way to get energy from pasture material and make money from manure. It reduces farm energy costs and increases profitability. You can make it yourself or have it installed. The price for it depends on the volume, starts from 7000 rubles.

The constant increase in the cost of traditional energy carriers is pushing home craftsmen to create home-made equipment that allows you to get biogas from waste with your own hands. With this approach to farming, it is possible not only to obtain cheap energy for heating the house and other needs, but also to organize the process of recycling organic waste and obtaining free fertilizers for subsequent application to the soil.

Excess produced biogas, as well as fertilizers, can be sold at market value to interested consumers, turning into money what is literally “lying underfoot”. Large farmers can afford to buy pre-fabricated biogas plants. The cost of such equipment is quite high. However, the return on its operation corresponds to the investments made. Less powerful installations operating on the same principle can be assembled on their own from available materials and parts.

What is biogas and how is it produced?

As a result of biomass processing, biogas is obtained

Biogas is classified as an environmentally friendly fuel. In terms of its characteristics, biog is in many ways similar to natural gas produced on an industrial scale. The biogas production technology can be represented as follows:

• in a special container called a bioreactor, the process of biomass processing takes place with the participation of anaerobic bacteria under conditions of airless fermentation for a certain period, the duration of which depends on the volume of loaded raw materials;
• as a result, a mixture of gases is released, consisting of 60% of methane, 35% of carbon dioxide, 5% of other gaseous substances, among which there is hydrogen sulfide in a small amount;
• the resulting gas is constantly withdrawn from the bioreactor and, after cleaning, is sent for its intended use;
• processed waste, which has become high-quality fertilizer, is periodically removed from the bioreactor and taken to the fields.

Visual diagram of the biofuel production process

In order to establish continuous production of biogas at home, one must own or have access to agricultural and livestock enterprises. It is economically profitable to engage in biogas production only if there is a source of free supply of manure and other organic animal waste.

Gas heating is still the most reliable heating method. You can learn more about autonomous gasification in the following material:

Types of bioreactors

Plants for the production of biogas differ in the type of loading of raw materials, the collection of the resulting gas, the placement of the reactor relative to the surface of the earth, and the material of manufacture. Concrete, brick and steel are the most suitable materials for building bioreactors.

According to the type of loading, bioinstallations are distinguished, into which a given portion of raw materials is loaded and goes through a processing cycle, and then is completely unloaded. Gas production in these units is unstable, but any kind of raw material can be loaded into them. As a rule, they have a vertical arrangement and take up little space.

A portion of organic waste is loaded daily into the system of the second type and a portion of ready-made fermented fertilizers equal to it in volume is unloaded. The working mixture always remains in the reactor. The so-called continuous loading plant consistently produces more biogas and is very popular with farmers. Basically, these reactors are located horizontally and are convenient if there is free space on the site.

The selected type of biogas collection determines the design features of the reactor.

• balloon systems consist of a rubber or plastic heat-resistant cylinder in which a reactor and a gas holder are combined. The advantages of this type of reactors are simplicity of design, loading and unloading of raw materials, ease of cleaning and transportation, and low cost. The disadvantages include a short service life, 2-5 years, the possibility of damage as a result of external influences. Tank reactors also include channel-type plants, which are widely used in Europe for the processing of liquid waste and sewage. Such a rubber top is effective at high ambient temperatures and there is no risk of damage to the cylinder. The fixed dome design has a fully enclosed reactor and a make-up tank for slurry discharge. The gas accumulates in the dome, when loading the next portion of the raw material, the processed mass is pushed into the compensation tank.
• Floating dome biosystems consist of a monolithic bioreactor located underground and a movable gas holder that floats in a special water pocket or directly in the feedstock and rises under the action of gas pressure. The advantage of a floating dome is the ease of operation and the ability to determine the gas pressure by the height of the dome. This is a great solution for a large farm.
• When choosing an underground or above-ground installation, it is necessary to take into account the slope of the relief, which facilitates the loading and unloading of raw materials, enhanced thermal insulation of underground structures, which protects the biomass from daily temperature fluctuations and makes the fermentation process more stable.

The design can be equipped with additional devices for heating and mixing raw materials.

Is it profitable to make a reactor and use biogas

The construction of a biogas plant has the following objectives:

• production of cheap energy;
• production of easily digestible fertilizers;
• savings on connection to expensive sewerage;
• processing of household waste;
• possible profit from the sale of gas;
• reducing the intensity of unpleasant odors and improving the environmental situation in the territory.

Graph of the profitability of the production and use of biogas

To assess the benefits of building a bioreactor, a prudent owner should consider the following aspects:

• the cost of the bio-installation is a long-term investment;
• home-made biogas equipment and installation of a reactor without the involvement of third-party specialists will cost much less, but its efficiency is lower than that of an expensive factory one;
• to maintain stable gas pressure, the farmer must have access to animal waste in sufficient quantities and for a long time. In the case of high prices for electricity and natural gas or the lack of the possibility of gasification, the use of the installation becomes not only profitable, but also necessary;
• for large farms with their own raw material base, a profitable solution would be to include a bioreactor in the system of greenhouses and cattle farms;
• for small farms, efficiency can be increased by installing several small reactors and loading raw materials at different intervals. This will help avoid interruptions in gas supply due to a lack of feedstock.

How to build a bioreactor on your own

The decision on construction has been made, now it is necessary to design the installation and calculate the necessary materials, tools and equipment.

Important! Resistance to aggressive acidic and alkaline media is the main requirement for the bioreactor material.

If a metal tank is available, it can be used provided that it has a protective coating against corrosion. When choosing a container made of metal, pay attention to the presence of welds and their strength.

A durable and convenient option - a polymer container. This material will not rot or rust. A barrel with thick rigid walls or reinforced will perfectly withstand the load.

The cheapest way is to lay out a container of brick or stone, concrete blocks. To increase the strength, the walls are reinforced and coated inside and out with a multi-layer waterproofing and gas-tight coating. The plaster must contain additives that provide the desired properties. The best shape that will withstand all pressure loads is oval or cylindrical.

At the base of this container, an opening is provided through which the waste material will be removed. This hole must be tightly closed, because the system works effectively only in sealed conditions.

Calculation of the necessary tools and materials

For laying out a brick container and arranging the entire system, you will need the following tools and materials:

• container for mixing cement mortar or concrete mixer;
• drill with mixer nozzle;
• crushed stone and sand for the device of a drainage pillow;
• shovel, tape measure, trowel, spatula;
• brick, cement, water, fine sand, rebar, plasticizer and other necessary additives;
• welding machine and fasteners for mounting metal pipes and components;
• water filter and a container with metal shavings for gas purification;
• tire cylinders or standard propane gas storage tanks.

The size of a concrete tank is determined from the amount of organic waste that appears daily in a private courtyard or farm. Full-fledged operation of the bioreactor is possible if it is filled to two-thirds of the available volume.

Let us determine the volume of the reactor for a small private farm: if there are 5 cows, 10 pigs and 40 chickens, then per day of their life a litter of 5 x 55 kg + 10 x 4.5 kg + 40 x 0.17 kg = 275 kg + 45 kg + 6.8 kg = 326.8 kg. To bring chicken manure to the required moisture content of 85%, add 5 liters of water. Total weight = 331.8 kg. For processing in 20 days it is necessary: ​​331.8 kg x 20 \u003d 6636 kg - about 7 cubes only for the substrate. This is two-thirds of the required volume. To get the result, you need 7x1.5 \u003d 10.5 cubic meters. The resulting value is the required volume of the bioreactor.

Remember that it will not work to produce a large amount of biogas in small containers. The output directly depends on the mass of organic waste processed in the reactor. So, to get 100 cubic meters of biogas, you need to process a ton of organic waste.

Preparing a site for a bioreactor device

The organic mixture loaded into the reactor should not contain antiseptics, detergents, chemicals that are harmful to the life of bacteria and slow down the production of biogas.

Important! Biogas is flammable and explosive.

For the correct operation of the bioreactor, it is necessary to follow the same rules as for any gas installations. If the equipment is airtight, biogas is discharged to the gas tank in a timely manner, then there will be no problems.

If the gas pressure exceeds the norm or will poison if the tightness is broken, there is a risk of an explosion, therefore it is recommended to install temperature and pressure sensors in the reactor. Inhaling biogas is also hazardous to human health.

How to ensure biomass activity

You can speed up the fermentation process of biomass by heating it. As a rule, in the southern regions such a problem does not arise. The ambient temperature is enough for the natural activation of fermentation processes. In regions with harsh climatic conditions in winter, without heating, it is generally impossible to operate a biogas plant. After all, the fermentation process starts at a temperature exceeding 38 degrees Celsius.

There are several ways to organize the heating of a biomass tank:

• connect a coil located under the reactor to the heating system;
• install electric heating elements at the base of the tank;
• provide direct heating of the tank by using electric heaters.

Bacteria that affect the production of methane are dormant in the raw material itself. Their activity increases at a certain temperature level. The installation of an automated heating system will ensure the normal course of the process. Automation will turn on the heating equipment when the next cold batch enters the bioreactor, and then turn it off when the biomass warms up to a predetermined temperature level.

Similar temperature control systems are installed in hot water boilers, so they can be purchased at stores specializing in the sale of gas equipment.

The diagram shows the entire cycle, starting from loading solid and liquid raw materials, and ending with the removal of biogas to consumers

It is important to note that you can activate the production of biogas at home by mixing the biomass in the reactor. For this, a device is made that is structurally similar to a household mixer. The device can be set in motion by a shaft, which is led out through a hole located in the lid or walls of the tank.

What special permits are required for the installation and use of biogas

In order to build and operate a bioreactor, as well as to use the resulting gas, it is necessary to take care of obtaining the necessary permits at the design stage. Coordination must be passed with the gas service, firefighters and Rostekhnadzor. In general, the rules for installation and operation are similar to the rules for using conventional gas equipment. Construction must be carried out strictly according to SNIPs, all pipelines must be yellow and have the appropriate markings. Ready-made systems manufactured at the factory are several times more expensive, but they have all the accompanying documents and meet all technical requirements. Manufacturers provide warranties for equipment and service and repair their products.

A self-made biogas plant can save on energy costs, which occupy a large share in determining the cost of agricultural products. A decrease in production costs will affect the increase in the profitability of a farm or a private farmstead. Now that you know how to get biogas from existing waste, it remains only to put the idea into practice. Many farmers have long since learned to make money from manure.