How to get biogas at home. Do-it-yourself biogas device

Let's assume that natural gas has not been and will not be in your village. And even if there is, it costs money. Although much cheaper than ruinous heating with electricity and liquid fuels. The nearest workshop for the production of pellets is a couple of hundred kilometers away, it is expensive to carry. It is getting more and more difficult to buy firewood every year, and it is troublesome to heat it. Against this background, it looks very tempting to get free biogas in your own backyard from weeds, chicken manure, manure from your favorite pig or the contents of the master's toilet. It is enough to make a bioreactor! On TV they tell how thrifty German farmers warm themselves with "dung" resources and now they don't need any "Gazprom". This is where the saying “will remove the film from feces” is true. The Internet is replete with articles and videos on the topic "biogas from biomass" and "do-it-yourself biogas plant". But little is known about the practical application of the technology: everyone and everyone is talking about the production of biogas at home, but few people have seen specific examples in the village, just like the legendary Yo-Mobile on the road. Let's try to figure out why this is so and what are the prospects for progressive bioenergy technologies in the countryside.

How wonderful it would be: I dreamed a little on the toilet, and the kettle was already boiling

What is biogas + a bit of history

Biogas is formed as a result of sequential three-stage decomposition (hydrolysis, acid and methane formation) of biomass by various types of bacteria. A useful combustible component is methane, hydrogen may also be present.

Bacterial decomposition process that produces combustible methane

To a greater or lesser extent, combustible gases are formed during the decomposition of any animal and vegetable residues.

The approximate composition of biogas, the specific proportions of the components depend on the raw materials and technology used

People have been trying to use this type of natural fuel for a long time, in medieval chronicles there are references to the fact that the inhabitants of the lowlands of present-day Germany a millennium ago received biogas from rotting vegetation, immersing leather furs in marsh slurry. In the dark Middle Ages and even the enlightened centuries, the most talented meteorists, who, thanks to a specially selected diet, were able to start up and set fire to abundant methane flatus in time, aroused the constant delight of the public at fun fair performances. Industrial biogas plants began to be built with varying degrees of success from the middle of the 19th century. In the USSR in the 80s of the last century, a state program for the development of the industry was adopted, but not implemented, although a dozen production facilities were still launched. Abroad, biogas production technology is being improved relatively actively, the total number of operating plants is in the tens of thousands. In developed countries (EEC, USA, Canada, Australia) these are highly automated large complexes, in developing countries (China, India) - semi-handicraft biogas plants for home and small farming.

Percentage of the number of biogas plants in the EU countries. It is clearly seen that the technology is actively developing only in Germany, the reason is solid state subsidies and tax incentives.

What is the use of biogas

It is clear that as fuel, since it burns. Heating of industrial and residential buildings, power generation, cooking. However, not everything is as simple as it is shown in the videos scattered on YouTube. Biogas must burn stably in heat generating plants. To do this, its parameters of the gaseous medium must be brought to fairly stringent standards. The content of methane should not be lower than 65% (optimum 90-95%), there should be no hydrogen, water vapor is removed, carbon dioxide is removed, the remaining components are inert to high temperatures. It is impossible to use biogas of “dung-animal” origin, which is not freed from malodorous impurities, in residential buildings.

The normalized pressure is 12.5 bar, at a value of less than 8-10 bar, automation in modern models of heating equipment and kitchen equipment stops the gas supply. It is very important that the characteristics of the gas entering the heat generator are stable. In the event of a pressure jump beyond the norm, the valve will work, you will have to turn it back on manually. It is bad if outdated gas appliances are used that are not equipped with a gas control system. In the best case, the burner of the heating boiler may fail. The worst option is that the gas will go out, but its flow will not stop. And this is fraught with tragedy. To summarize what has been said: the characteristics of biogas must be brought to the required parameters, and safety precautions must be strictly observed.

Simplified process chain for biogas production. An important stage is separation and gas separation

What raw materials are used to produce biogas

• Vegetable raw materials are excellent for biogas production: from fresh grass you can get the maximum fuel yield - up to 250 m3 per ton of raw materials, methane content up to 70%. Somewhat less, up to 220 m3 can be obtained from corn silage, up to 180 m3 from beet tops. Any green plants are suitable, algae, hay (100 m3 per ton) are good, but it makes sense to use valuable feed for fuel only if there is a clear excess of it. The output of methane from the pulp, which is formed in the manufacture of juices, oils and biodiesel, is low, but the material is free. The lack of vegetable raw materials is a long production cycle, 1.5-2 months. Biogas can also be obtained from cellulose and other slowly decomposing plant waste, but the efficiency is extremely low, little methane is produced, and the production cycle is very long. In conclusion, we say that vegetable raw materials must be finely ground.
• Raw materials of animal origin: traditional horns and hooves, waste from dairies, slaughterhouses and processing plants are also suitable and also in crushed form. The richest "ore" is animal fats, the output of high-quality biogas with a methane concentration of up to 87% reaches 1500 m3 per ton. However, animal raw materials are in short supply and, as a rule, they find other uses for it.

Combustible gas from excrement

• Manure is cheap and available in abundance on many farms, but the yield and quality of biogas is much lower than from other types. Cow patties and horse apples can be used in their pure form, fermentation starts immediately, biogas yield is 60 m2 per ton of raw materials with a low methane content (up to 60%). The production cycle is short, 10-15 days. Pig manure and chicken manure are toxic - so that beneficial bacteria can develop, it is mixed with plant waste, silage. Detergent compositions, surfactants, which are used in the cleaning of livestock buildings, present a big problem. Together with antibiotics, which get into the manure in large quantities, they inhibit the bacterial environment and inhibit the formation of methane. It is completely impossible not to use disinfectants, and agricultural enterprises that have invested in the production of gas from manure are forced to find a compromise between hygiene and animal disease control on the one hand and maintaining the productivity of bioreactors on the other.
• Human excrement, completely free, is also suitable. But it is unprofitable to use ordinary sewage, the concentration of feces is too low and disinfectants and surfactants are high. Technologists say that they could only be used if “products” only come into the sewer from the toilet, provided that the bowl is flushed with only one liter of water (standard 4/8 l). And no detergents, of course.

Additional requirements for raw materials

A serious problem faced by farms that have installed modern equipment for biogas production is that raw materials should not contain solid inclusions; a stone, nut, piece of wire or board that accidentally gets into the mass will clog the pipeline, disable an expensive fecal pump or mixer.

It must be said that the given data on the maximum gas yield from the feedstock correspond to ideal laboratory conditions. In order to approach these figures in real production, it is necessary to observe a number of conditions: maintain the required temperature, periodically mix finely ground raw materials, add additives that activate fermentation, etc. On a makeshift installation, assembled according to the recommendations of articles on “obtaining biogas with your own hands”, you can barely reach 20% of the maximum level, high-tech installations can achieve values ​​​​of 60-95%.

Sufficiently objective data on the maximum yield of biogas for various types of raw materials

Biogas plant device

• "Home" biogas plant. At a minimum, it is necessary to have two sealed vessels, a bioreactor and an accumulator, into which gas is discharged through a tube. It is desirable to have a third vessel, where biogas will be pumped under pressure, then moisture will partially settle in the second. The design is not much different from the moonshine still. It would be nice to constantly stir the raw materials, for this you need a stirrer and an electric motor or a healthy hardy man. It is not worth counting on high productivity and good quality of biogas.
• Industrial plant for the production of biogas. We will not go into details, it is better to give a schematic diagram:

The equipment includes, at a minimum, a reactor and a gas tank, a separator, agitators, pumps, a compressor station, a constant temperature system, safety devices, and controls. To intensify processes, cavitators, devices for analyzing the environment and introducing activators, etc. are also used.

The composition of the resulting biogas must be normalized, after storage it enters the separation and sorption columns, then it is brought to the required pressure in the gas tank and only then it enters the line leading to the heat generators.

Bioenergy production as part of a modern livestock complex. The inclusion of greenhouses and a fertilizer plant in its composition increases profitability.

Is biogas production profitable?

We have already mentioned that in developed countries they build large industrial installations, while in developing countries they build mainly small ones, for a small economy. Let's explain why this is so:

• Poor countries. In a makeshift installation, with its monstrous inefficiency, all work can be done manually. For countries where peasants are paid mere pennies for hard work, this is a benefit. Moreover, in warm regions, the crop can be harvested several times a year and cheap plant materials are in abundance. Investments in the simplest system are relatively small, people are ready to put up with the low quality of biogas. It is cheaper for the owner to attach an “observer” to an antediluvian boiler or stove than to purchase equipment for normalizing biogas.

Chinese farmers procure raw materials for biogas production

• rich countries. In Germany, the world leader in biogas production, almost half of the poultry and large livestock farms produce their own methane. The processes are automated as much as possible, the quality of biogas is high, and the production capacities are large. Waste raw materials undergo additional processing, mineralization, as a result of which the farms receive a disinfected non-aggressive complex fertilizer. Despite the high rates of methane yield from raw materials, and considerable prices for energy carriers, experts say that biogas energy justifies itself for farmers only because the state subsidizes 50% of the cost of equipment. An additional benefit can be obtained by generating electricity from gas. First, the government buys it at inflated prices; secondly, the consequences of uneven seasonal biogas production can be minimized in this way. The state also pays extra for improving the ecological state of lands as a result of using not aggressive manure, but “soft” fertilizer.

Biogas production in Germany: environmentally friendly, aesthetically pleasing, only possible with financial support from the federal government

• Russia. At the very least, biogas energy is also developing in our country. From time to time, the media report on the launch of the next production, in an interview, a joyful scientist, designer or director of the farm reports that the payback period for the installation is one year. But life makes its own adjustments. Over time, it turns out that the operating costs were not taken into account when drawing up the business plan, in practice the gas yield is much lower than planned, and the fermentation time is much longer. Those who have worked for half a year already say the payback period of investments is 5 years. And after this time, people generally try not to give interviews. Unfortunately, we have scattered teams engaged in bioenergy and there are no reliable data on profitability in Russia. In general, it can be assumed that, taking into account lower energy prices than in the West and the availability of local fuels, biogas production in our country is on the verge of profitability, which does not contribute to its development without state support.

Does it make sense to produce biofuels at home?

Is it profitable to produce biofuel at home in small quantities on a personal subsidiary plot? If you have a few metal barrels and other iron junk, as well as an abyss of free time and you do not know how to dispose of it - yes. But the savings, alas, are scanty. And investing in high-tech equipment with small volumes of raw materials and methane production does not make sense in any case.

Another video of domestic Kulibin

Without mixing the raw materials and activating the fermentation process, the methane yield will be no more than 20% of the possible. This means that in the best case, from 100 kg (bunker loading) of selected grass, you can get 5 m3 of gas without taking into account compression. And it will be good if the methane content exceeds 50% and it is not a fact that it will burn in the heat generator. According to the author, the raw material is loaded daily, that is, its production cycle is one day. In fact, the required time is 60 days. The amount of biogas received by the inventor, contained in a 50-liter cylinder, which he managed to fill, in frosty weather for a heating boiler with a power of 15 kW (a residential building of about 150 m2) is enough for 2 minutes.

Those who are interested in the possibility of biogas production are advised to carefully study the problem, especially from a financial point of view, with technical questions, contact specialists with experience in such work. The practical information obtained in those farms where bioenergy technologies have already been used for some time will be very valuable.

Owners of private houses located in regions with limited access to traditional fuels should definitely pay 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 yourself.

The mechanism of action of biogas plants

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

In the reactor, under the influence of anaerobic bacteria, the biomass is rapidly decomposed. During the fermentation of organic raw materials, biogas is released. Approximately 70% of the composition of such a gas is methane, the rest is carbon dioxide.

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

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

Biogas plants on a silo. 1 Silos. 2 Biomass loading system. 3 Reactor. 4 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 about 1.5 m3 of biogas. The daily manure of 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 gives about the same amount of thermal energy as 3.5 kg of firewood, 1-2 kg of coal, 9-10 kWh of electricity.

The simplest biogas mixture recipe includes the following components:

• cow dung - about 1500 kg;
• rotted leaves or other organic waste - 3500 kg;
• water - 65-75% of the total mass of the previous components. Pre-heat the water to about 35 degrees.

This amount of biomass will be enough to produce biogas for half a year of operation with moderate consumption. On average, biogas begins to be released within 1.5-2 weeks after loading the mixture into the plant.

Gas can be used to heat the house and a variety of household and household buildings.

Construction of a typical biogas plant

biogas plant

The main components of a complete biogas system are:

• reactor;
• humus supply system;
• agitators;
• biomass;
• gasholder;
• separator;
• protective part.

A domestic installation will have a somewhat simplified design, however, for completeness of perception, 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 hermetic container, on top of which a dome is installed, usually having a spherical shape.

Currently, the most popular are the collapsible design reactors made using innovative technologies. Such a reactor can be easily assembled with your own hands with minimal time. If necessary, it is just as easy to disassemble and transport to another place.

Steel is convenient in that you can easily create holes in it for connecting 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 waste receiving bin, a water inlet pipe and a screw pump designed to send the humus to the reactor.

A front loader is used to load the dry component into the bunker. At home, this task can be done without a loader, using various improvised means, for example, shovels.

In the bunker, 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.

Agitators

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 in order to achieve the most uniform fermentation process of the mixture that the design of a typical biogas plant includes agitators 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.

Inclined mixers are mounted on the side surfaces of the reactor. An electric motor is responsible for the rotation of the screw in the fermenter.

Automated heating system

For successful production of biogas, the temperature inside the system must be maintained at +35-+40 degrees. To do this, automated heating systems are included in the design.

The source of heat 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 a variety of adverse natural phenomena.

gas holder

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

For the manufacture of gas-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 the spent humus and obtaining, 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 drained humus is sent to the shipping compartment. The system sends the liquid part back to the receiving chamber. Here, the liquid is applied to moisten the new feedstock.

The simplest do-it-yourself biogas plant

Biogas plant for home

A domestic biogas plant will have a somewhat simplified design, but its manufacture should be approached with the utmost 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 the most difficult part of the manufacture of the system under consideration 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 solid-bottomed polymer rings. Such devices provide 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. Equip a gas drainage system. This saves you the hassle of buying and installing agitators, which saves time and money on assembling the plant.

The simplest version of the gas drainage system is vertically fixed PVC sewer pipes with many holes in the body.

Choose 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 foil insulation. Thanks to the film, conditions will be created for the accumulation of biogas under the dome under conditions of slight overpressure.

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

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

Procedure and conditions for the successful use of a biogas plant

Average specific yield of biogas

Thus, it is not difficult to assemble a simple biogas plant on your own. 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 kinds of solvents, antibacterial drugs and other similar substances.

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

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

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

Successful work!

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

Video - DIY biogas plant

svoimi-rykami.ru

Biogas plant on your own

The article on biogas production presented the theoretical foundations 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. In this article, practical implementations of biogas plants will be given, with a description of some improvised designs.

As energy prices are rising and many livestock and small farm owners have problems with waste disposal, biogas industrial complexes and small biogas plants for a private home have come on the market. Using search engines, the Internet user can easily find an affordable turnkey solution to meet the needs of the biogas plant and its price, get in touch with equipment suppliers and agree on the construction of a biogas generator at home or on the farm.

Biogas industrial complex

Bioreactor - the basis of a biogas plant

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

The collected biogas exerts pressure on the cylinder, causing it to rise above the tank. Thus, the bell also performs the function of a gas tank - a temporary storage of the resulting gas.

Floating Dome Bioreactor

The disadvantage of the bell design of a biogas reactor is the impossibility of mixing the substrate and heating it during the cold periods of the year. Also a negative factor is a strong smell, and unsanitary conditions due to the open 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 a hot climate.

Another example of a floating dome bioreactor

In order to prevent environmental pollution and eliminate unpleasant odors, the reactors of biogas plants for home and large industries have a fixed dome design. The shape of the structure in the process of gas formation does not matter much, 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 nozzles for adding new portions of biomass and removing the spent substrate.

A variation of the fixed dome bioreactor

Main types of biogas plants

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

• Portion, with a single load of the entire biomass, and with subsequent full unloading after the processing of raw materials. The main disadvantage of this type of bioreactors is the uneven release of gas during the processing of the substrate;
• continuous loading and unloading of raw materials, due to which a uniform release of biogas is achieved. Due to the design of the bioreactor during loading and unloading, biogas production does not stop and there are no leaks, since the nozzles through which the addition and removal of biomass is carried out are made in the form of a water seal that prevents gas from escaping.

Batch bioreactor example

Batch biogas reactors can be of any design that prevents gas leakage. So, for example, at one time in Australia, channel methanetanks with an elastic inflatable roof were popular, where a slight overpressure inside the bioreactor inflated a bubble of durable polypropylene. Upon reaching a certain level of pressure inside the bioreactor, the compressor was turned on, pumping out the generated biogas.

Channel bioreactors with flexible gas holder

The type of fermentation in this biogas plant can be mesophilic (with weak 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 the absence of the need for an intermediate receiver, but the big disadvantage is the vulnerability of the elastic dome to mechanical damage.

Large channel bioreactor with flexible gas tank

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

Dry-type bioreactors look like a sealed garage with tightly closing doors. The biomass is loaded into the reactor using a front loader and remains in this state until the completion of the complete gas generation cycle (about half a year), without the need to add the substrate and mix it.

Batch bioreactor loaded through a hermetically sealed door

DIY biogas plant

It should be noted that in most bioreactors, as a rule, only the gas generation 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, due to which the level of biomass in them is somewhat higher than inside the tank.

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

These designs of home-made bioreactors are popular among folk craftsmen who independently make biogas plants with their own hands for the home, allowing reusable manual loading and unloading of the substrate. In the manufacture of bioreactors with their own hands, many craftsmen experiment with completely sealed containers, using several rubber chambers from the tires of the wheels of large vehicles as a gas holder.

Drawing of a gas tank made from tractor chambers

In the video below, an enthusiast of homemade biogas production, using the example of barrels filled with bird droppings, proves the possibility of actually obtaining combustible gas at home, processing poultry waste into useful fertilizer. The only thing that can be added to the design described in this video is that you need to put 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 the owners, who have to clean manure every day, do not need this theory, because they know the amount and mass of the future substrate through their own practice. 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 of obtaining the amount of manure from some animals with an approximate calculation of the biogas yield

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

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

Construction of a masonry bioreactor

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 resistant and effective strains of bacteria methanogens 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 and cleaning biogas

The constant production of gas 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 the instability of the overpressure in the bioreactor can lead to the extinction of the flame, followed by the release of poisonous gas. The use of such a primitive biogas plant connected to a stove is categorically unacceptable because of the possibility of poisoning with toxic components of raw biogas.

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

Therefore, almost any scheme of a biogas plant 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. The tank for temporary storage of biogas can be made of chambers from tires, from which the gas is pumped 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 to store and transport biogas.

As an alternative to the mandatory use of a gas tank, an improved floating dome bioreactor can be perceived. The improvement consists in the addition of a concentric baffle which forms a water pocket that acts like a water seal and prevents the biomass from coming into contact with air. The pressure inside the floating dome will depend on its weight. By passing the gas through the purification system and reducer, it can be used in a household stove, periodically bled from the bioreactor.

Bioreactor with floating dome and water pocket

Grinding and mixing of the substrate in the bioreactor

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

1. mechanical agitators driven by an electric motor or manually;
2. circulating mixing with a pump or propeller pumping the substrate inside the bioreactor;
3. bubbling mixing by blowing the already existing biogas into the liquid biomass. 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 carried out 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 has a mechanical agitator

Substrate heating in mesophilic and thermophilic biogas plants

The optimal temperature for gas formation is the temperature of the substrate in the range of 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 thermal switch or thermocouples connected to the 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 inside its biomass will burn. The burnt substrate will reduce heat transfer and the quality of heating, 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 of the bioreactor

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

Insulation of the bioreactor with thermal insulation material

Practical experiences that are inevitable when building biogas plants with your own hands

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

Therefore, many novice masters follow the path of independent experiments in obtaining biogas, starting with small containers, determining how much gas from the available raw materials is produced by their small experimental biogas plant. Component prices, methane output and the future costs of building a complete working biogas plant will determine its viability and feasibility.

In the video above, the master demonstrates the capabilities of his biogas plant, noting how much biogas will be produced in one day. In his case, when pumping eight atmospheres into the compressor receiver, the volume of the resulting gas after recalculations, taking into account the volume of the tank 24 l, will be about 0.2 m².

This amount of biogas obtained from a 200 liter barrel is not significant, but, as shown in the following video of this wizard, 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 obtaining biogas and biologically pure fertilizers by processing organic waste in a biogas plant. It must be borne in mind that the value of organic fertilizers may exceed the cost of the resulting gas, and then biogas will become a useful by-product of the process of making 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.

infoelectric.ru

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

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

Along with solar and wind power plants, installations have appeared for obtaining gaseous fuels called biogas from organic waste.

A remarkable feature of this technology is its simplicity: anyone can implement it on a small scale. So, do-it-yourself biogas - that's what the conversation will be about.

If we owe the appearance of solar panels and wind turbines 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.

As the name suggests, the main component of biogas is methane, which is also contained 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 a natural microflora that lives in the intestines of cattle and decomposes its contents. These bacteria are carried outside with manure, which is used to fuel the new gas generating plant.

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 subjected to fermentation with the formation of biogas. At the same time, the raw material turns into the most valuable fertilizer.

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

Factors affecting 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 a large amount of fat. The least profitable type of raw material is cattle manure.

Manure - raw material for biogas

Temperature

With increasing temperature, the productivity of bacteria increases. According to the temperature regime, gas generators are divided into three types.

Psychrophilic

These are installations without heating, in which the temperature is maintained in the range from 18 to 25 degrees. At the moment, they are almost never used.

mesophilic

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

Advantages:

• low energy consumption;
• the amino acid composition of fertilizers is the most useful.

Flaws:

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

thermophilic

Intensive heating is applied, the temperature exceeds 40 degrees.

Advantages:

• high performance;
• pathogenic bacteria die.

Flaws:

• high energy costs;
• low quality fertilizers.

Thermophilic bioreactor on manure

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

• due to the increase in energy costs, the profitability of the installation will decrease;
• as the temperature rises, 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 sufficiently liquefied so that microbes and gas bubbles can move in it. To do this, hot water is added to the installation, bringing the load humidity to 85% in winter and up to 92% in summer.

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

Fermentation time

If the 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.

With excessively long exposure, productivity is also reduced due to a lack of nutrients.

On average, the optimal fermentation time is:

• for 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. Carbon should be 10 to 20 times more than nitrogen.

Comparison of biogas with more traditional fuels

The strengths of this technology include:

1. The raw material used to produce biogas is an inexhaustible resource and is free of charge.
2. Biogas energy is not tied to a specific place - 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 capacity), biogas plants are between nuclear (5 thousand euros per 1 kW) and coal (2 thousand euros per 1 kW) stations.

Biogas plant

In practice, it has been proven that the greater the power of the installation, the cheaper the energy generated with its help. Also, profitability depends on the type of raw materials used.

Scheme of organizing the production of biogas at home

When constructing a gas generator with a capacity of more than 10 MW, operating on food waste, it will be necessary to spend about 2 thousand euros for each kW of power; at the same time, a plant with a capacity of up to 1 MW, using cow dung as a raw material, will cost 7 thousand euros per 1 kW.

The unit consists of several technological units.

Reactor

Represents the integral reinforced concrete capacity upholstered with thermal insulation with several technological openings. The reactor must be hermetically sealed to prevent air from entering its interior.

Biomass Feeding System

To load raw materials, the plant is equipped with a bunker. Waste is fed here manually or with the help of a conveyor.

Also, a pipe with hot water is supplied to the reactor.

Agitators

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

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

The motor can be turned on manually or automatically.

Automated heating system

Heating is installed at the bottom of the reactor. The heat carrier can be water or electricity. The heating elements are switched on by a thermostat set to a certain temperature.

gas holder

This is a 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 supply to the consumer.

The simplest do-it-yourself biogas plant for home

A self-made biogas generator, of course, is inferior in performance to expensive factory-made plants, but it will require significantly lower initial costs.

For its construction 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 water supply and discharge of the finished product.

The volume of the reactor should exceed the volume of the load by 1.5 times.

Installation scheme

In the simplest version, the gas generator is not equipped with heating and mixing device. Works on the construction of the installation are 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 the other, forming a cylindrical tank from them. All joints should be sealed with bituminous mastic.
3. The concrete container is pasted over with thermal insulation and waterproofing, after which they proceed to backfill the pit.
4. A lid with a tightly closed loading hatch is placed on top of the reactor. During the fermentation of raw materials in the reactor, high pressure is formed, so the lid can be secured with cables for reliability. It will not be superfluous to install a safety valve in it with a counterweight in the form of a weight.
5. It is necessary to attach the bunker to the loading hatch.
6. It remains to connect pipelines to the reactor. At the same time, a water seal must be installed on the line of discharge of the finished product.

Biomass is prepared as follows:

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

In order to increase productivity, a more advanced installation scheme can be applied, including water heating. A hot water boiler operating on the fuel produced by the plant will act as a heat generator.

DIY biogas plant - drawing

When loading raw materials, it is enough to warm 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 load of biomass allows for 6 months to receive an average of about 40 cubic meters per day. m of gaseous fuel.

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microclimat.pro

Do-it-yourself biogas plant for a private house: recommendations for the device and an example of homemade arrangement

A prudent owner dreams of cheap energy resources, efficient waste disposal and obtaining fertilizers. A do-it-yourself home biogas plant is an inexpensive way to make dreams come true. Self-assembly of such equipment will cost reasonable 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 do you need to get biogas

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

By its properties, it practically does not differ from natural gas, which is used for industrial and domestic needs.

If desired, each homeowner can purchase an industrial 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 a particular impact on the environment. Moreover, as a raw material for biogas, waste products that need to be disposed of are used. They are placed in a bioreactor where processing takes place:

• For some time, the biomass is exposed to bacteria. The fermentation period depends on the volume of raw materials.
• As a result of the activity of anaerobic bacteria, a combustible mixture of gases is released, which includes methane (60%), carbon dioxide (35%) and some other gases (5%). Also, during fermentation, potentially dangerous hydrogen sulfide is released 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 cleaned and enters the gas tank, where it is stored until it is used for its intended purpose.
• Gas from a gas tank 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 an additional effort, but the effort pays off. After fermentation, the raw material turns into high-quality fertilizer, which is used in fields and 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, out of 1 cubic meter. substrate can be obtained 70-80 cubic meters. biogas, but gas production is uneven and depends on many factors, incl. biomass temperature. This complicates the 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 put the substrate into the fermenters with a time difference. Such installations operate in parallel, and the 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 doubles the production of gas. Although the arrangement of heating requires investment, it pays off with greater design efficiency.

Homemade biogas equipment, assembled from improvised materials, is much cheaper than industrial production plants. Its efficiency is lower, but it fully corresponds to the invested funds. If you have access to manure and the desire to make your own efforts to assemble and maintain the structure, this is very beneficial.

Advantages and disadvantages of the system

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

• Recycling. Thanks to a biogas plant, you can get the most out of the garbage that you would have to get rid of anyway. This disposal is less hazardous to the environment than landfill.
• Renewability of raw materials. Biomass is not coal or natural gas, the extraction of which depletes resources. In agriculture, raw materials appear constantly.
• Relative 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 emission. When biogas is burned, a small amount of sulfur is released into the atmosphere. This is a negative phenomenon, but its scale is known in comparison: when natural gas is burned, environmental pollution with sulfur oxides is much greater.
• Stable work. Biogas production is more stable than solar panels or windmills. If solar and wind power cannot be controlled, then biogas plants depend on human activity.
• You can use multiple settings. Gas is always a risk. To reduce potential damage in the event of an accident, several biogas plants can be dispersed around the site. If correctly designed and assembled, a system of several fermenters will work more stable than one large bioreactor.
• Benefits for agriculture. Some types of plants are planted to obtain biomass. You can choose those 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 ways that 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 give enough of it 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 m3 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 in the coming years, and the amount of energy needed, 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 inconvenience and carefully control the process so as not to provoke the spread of pathogens

For laying in a bioreactor, a substrate is prepared, which includes several components in the following proportions:

• manure (preferably cow or pig) - 1.5 tons;
• organic waste (it can be rotted leaves or other components of plant origin) - 3.5 tons;
• 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 bookmark for six months, based on moderate gas consumption. After about 10-15 days, the fermentation process will give the first results: the 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 common in our country. This is largely due to poor awareness of people about the benefits and features of biogas systems. In China and India, many small farms are equipped with makeshift installations to generate additional clean fuel

If the plant 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 there is no experience in assembling complex systems, it makes sense to pick up on the net or develop the simplest drawing of a biogas plant for a private house.

The simpler the design, the more reliable and durable it is. Later, when building and system handling skills become available, it will be possible to remake the equipment or mount an additional installation.

Expensive industrial structures include biomass mixing systems, automatic heating, gas purification, etc. Household equipment is not so difficult. It is better to assemble a simple installation, and then add elements that need to arise.

When calculating the volume of the fermenter, it is worth focusing on 5 cubic meters. Such an installation allows you to get the amount of gas needed 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 indicator, because the calorific value 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 regime. 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: preparation of a pit for a bioreactor

Almost the entire biogas plant is located 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 the fermentation of the substrate and the gas output depend on the preparation of the walls and the 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 best solution is to buy ready-made polymer rings with a blank bottom. They will cost more than improvised materials, but additional sealing is not required. Polymers are sensitive to mechanical stress, but they are not afraid of moisture and chemically aggressive substances. They are not repairable, but if necessary, they can be easily replaced.

Stage 2: arrangement of gas drainage

Buying and installing special agitators for biogas plants is expensive. The system can be reduced in cost by equipping gas drainage. It is a vertically installed polymer sewer pipes, in which many holes have been made.

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

When calculating the length of the drainage pipes, one should be guided by the planned filling depth of the bioreactor. The tops of the pipes must be above this level.

Stage 3: arrangement of the insulating layer

The substrate can be immediately loaded 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, it will ensure the 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. At the highest point of the dome, a gas outlet pipe is installed and pulled to the gas tank.

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

The capacity of the bioreactor is closed with a tight lid. To prevent mixing of biomethane with air, a water seal is equipped. It also serves to purify gas. It is necessary to provide a release valve that will work if the pressure in the fermenter is too high.

Two ways to heat the bioreactor

Microorganisms that process the substrate are constantly present in the biomass, however, for their intensive reproduction, a temperature of 38 degrees and above is required. For heating during the cold period, you can use a coil connected to the home heating system, or electric heaters. The first method is more cost-effective, so it is more often used.

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

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

Video materials on assembling and arranging the system

Although there is nothing complicated in assembling and arranging biogas equipment, you need to be extremely attentive to details. Errors are not allowed, because can lead to explosions and destruction. We offer video instructions that will help you understand how the plants are arranged, assemble them correctly and supplement them with useful devices for more convenient use of biogas.

The video shows how a standard biogas plant works:

An example of a homemade biogas plant. Video tutorial on arranging the system with your own hands:

Video instruction for assembling a biogas plant from a barrel:

Description of the manufacturing process of substrate agitators:

A detailed description of the work of a makeshift gas storage:

No matter how simple the biogas plant chosen for a private house is, it is not worth saving on it. If possible, it is better to buy a collapsible bioreactor of industrial production. If not, make it from high-quality and sustainable materials: polymers, concrete or stainless steel. This will create a truly reliable and safe gas supply system at home.

sovet-ingenera.com

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

Of course, do-it-yourself biogas is not for everyone. First, you must be the owner of a private house. A home-made installation has dimensions and installation options in which the conditions of the apartment are categorically not suitable. Secondly, at home it is possible only if there is a large amount of organic waste. And thirdly, perhaps most importantly, knowledge is needed.

It makes no sense to come up with an installation - everything has already been invented a long time ago. But in order to implement a ready-made idea according to ready-made drawings, this must be understood. A tool, ingenuity, understanding and awareness of the scheme of the device, and also a desire that will allow you not to deviate from the intended goal - this is all very important.

To summarize:

• Place. Only private courtyards, where there are plots up to 10 m2 free from buildings and trees. It is also worth considering such options when, in the future, it is possible to construct a building of an economic or even residential type above the installation itself.
• Material. Stainless steel, brick, concrete, pipes (metal and/or plastic) are the most basic. Let's add tools to this list: welding equipment, concrete mixers, metal-cutting tools.
• Raw material. The main source of biogas can only be organic matter - manure, waste of plant origin, waste from the slaughterhouse. Each type of raw material gives its own amount of biogas of a certain quality. In any case, there should be enough raw materials to increase profitability.
• Understanding and comprehension of the idea. You can do without it: invited, paid, received - why understanding? But even the most primitive and designed for small biogas production is expensive, and the whole point is to get everything you need, based on your own strength. So here you have to be the bearer of the unspoken title of "craftsman".

Many European farmers have long switched to this alternative fuel. The payback of a biogenerator is 3-5 years, it all depends on the scale of consumption. For example, Danish owners of mini-farms, with only 50-100 head of livestock, manage to obtain biogas with their own installations, which fully meets the needs of both a residential building and the farm itself. The comfort at home and on the farm, thanks to their own biogas production, is perceived by them as already something ordinary.

How it works

In the entire biological installation, almost every element is the main one:

• Tank - a container in which the fermentation of biomass occurs due to the action of bacteria. Different sizes and from different materials, the tank serves as a kind of pan. It would be more correct to call it a bioreactor. This complex structure must not only contain the biomass for fermentation, but also have such qualities as reliability and durability. The biogas plant is not a reusable building. You need to do it once and only improve the design, otherwise the profitability will fall below zero.
• Connecting elements that must not poison the gas. Methane is an explosive gas and an accidental spark can lead to disastrous consequences.
• Raw material mass mixing system. In artisanal conditions, it is quite difficult to make, but it is highly desirable. Regular mixing improves productivity.
• Reactor insulation system. Reliable and high-quality insulation allows maintaining the required temperature inside the reactor. Bacteria are able to survive at low temperatures, but they are not viable. And although the temperature inside will always be above zero, it must be able to maintain and control it.
• Gas holder - a container for temporary (until consumption) storage of gas. In artisanal conditions, it is represented by a steel tank.
• Filtration system or filtration system. It is desirable to clean the gas obtained as a result of fermentation from CO2.

The raw material, entering the bioreactor, begins to ferment. The emitted gas is not clean. It contains the proportion of methane (up to 80-90%), carbon dioxide (up to 20-30%), hydrogen (up to 5-10%). Intermittent agitation promotes the frequency of outgassing. Gas enters the gas tank, then to the filtration system, and then to the consumed unit (boiler, furnace, etc.).

Basic moments

Biogas at home can be obtained in different volumes and different qualities. Several factors influence this:

• The amount of raw materials. For continuous operation of the bioreactor, biomass must be periodically fed inward. The feeding frequency depends on the dimensions of the reactor. High performance is achieved by filling the tank by 75%. A lower value reduces the efficiency of production, as well as a load of more than 75%.
• Origin of raw materials. Manure or corn mass - the difference is significant. Usually they start from the presence of one or another type of raw material. For example, a huge amount of high quality methane can be obtained from animal fats - up to 1500 m3 per ton of raw materials. At the same time, the methane content will also be the maximum possible - up to 90%. The production of biogas from algae has lower indicators - up to 250-300 m3 per ton.
• Feed frequency. Fermentation must be completed almost completely, the released water must be drained, unfermented residues disposed of, and only then a new supply of a certain amount is possible. In artisanal conditions, this process is quite difficult to control. Industrial installations are more progressive and the whole process is controlled by automation.
• Combination of raw materials. Some types of biomass can complement each other, acting as catalysts for chemical processes inside the reactor. Some, on the contrary, are able to slow down the course of the reaction. For example, grain stillage in combination with manure gives good results as a result of the combination. Whereas fats are not combined with almost any other type of raw material.

The table shows the volume of gas produced (in m3) from one ton of raw material:

How to use

Biogas at home can be used based on its quantity and quality. Usually this is the heating of outbuildings or a residential building. With small volumes of gas, it can only be enough to heat water, but in this case, it is necessary to reconsider the profitability of the installation. Some craftsmen have brought their designs to enormous performance levels and completely forgot about the consumption of state-owned electricity and natural gas.

In any case, by means of a biogas plant, several positive aspects are realized both for the gas consumer and for all mankind as a whole:

• transition to low-cost production,
• savings,
• partial waste disposal,
• prevention of global warming.

Mankind has made a giant leap forward, having learned to control nature and life. Biogas, as an alternative fuel and type of energy, has now become possible to obtain at home. Of course, the high cost of equipment is somewhat scary, but payback calculations show that a bioreactor at home is a profitable and expedient solution.

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.

Biogas is a mixture of gases that are formed during the decomposition of organic matter by anaerobic bacteria. Biogas is highly flammable and forms a clean flame when burned, so it can be used not only for cooking, but also for internal combustion engines (for example, for the production of electricity).

Advantages of a biogas plant at home:
- you can easily get biogas at home without the use of expensive equipment;
- an excellent alternative energy for those whose housing is located far from civilization, or for those who wish to be independent of the state;
– available raw materials (manure, kitchen waste, shredded vegetation, etc.);
– concern for the environment, since in the process of decomposition of organic substances in nature, gas enters the atmosphere, which entails a greenhouse effect, and in this case, biogas will be burned, while producing CO2;
– obtaining fertilizers as a by-product of a biogas plant.

But apart from the advantages, biogas plant has its drawbacks:
- bacteria work at a temperature of 18-40 degrees, so you can get biogas in the summer. If the biogas plant is insulated and equipped with heating, then it is possible to obtain biogas in the spring-autumn period, but the costs of insulation and heating may negate the benefit
- it is necessary to constantly introduce new raw materials, and therefore drain fertilizers.

To make a biogas plant with our own hands, we need:
1. Two barrels for 200l
2. A barrel of 30-60 liters, or a large plastic bucket
3. Plastic sewer pipes
4. Gas hose
5. Faucet

For clarity, I will diagram of a home biogas plant

The principle of operation of a biogas plant. Raw materials (manure, kitchen waste, chopped vegetation, etc.) and water are loaded into the reactor. The biogas plant will not work immediately, but after a few days, when the number of anaerobic bacteria will increase to a maximum.

During the life of anaerobic bacteria, biogas is released, which will be collected at the top of the barrel (a tap should be located in this place). From the reactor, biogas enters the collector through a gas hose.

The collector is a barrel of 200 liters of water, and a bucket inverted in it to collect gas, as well as to create the pressure necessary for the operation of a gas furnace. As gas enters, the bucket will float. If the amount of biogas is greater than the plastic bucket can hold, then the gas will simply go out through the water.

For the manufacture of the reactor You will need a sealed barrel of 200 liters. We make several holes in the upper part of the barrel and install:
– Plastic pipe for pouring raw materials. At the end of the pipe, it is necessary to install a transition to a large pipe (a kind of watering can, for the convenience of pouring raw materials)
– A plastic pipe for draining fertilizers. Since a biogas plant is not a perpetual motion machine, and it is necessary to constantly bring in raw materials. When new raw materials are introduced, the surplus (already processed raw materials - fertilizers) will exit through the drain pipe.
– Tap at the highest point of the barrel for collecting biogas.

In the manufacture of the reactor, it is very important that all connections are tight, otherwise, under the pressure that has arisen, the gas may leak out. The drain pipe must be located below the installation level of the gas cock. The drain and fill pipes must be tightly plugged when not in use.

To make a collector, you will need a 200 l plastic barrel without a lid. Pour 3/4 of the water into the barrel and install another barrel, upside down, smaller in volume. In the bottom of a barrel of a smaller volume, we cut a fitting for connecting a hose from the reactor, and a tap for connecting a hose going to a gas furnace.

To fill the raw materials, open the inlet and outlet and fill in the raw materials. It is best to use manure diluted in water. It is best to use rainwater or settled water so that the chlorine content from the water supply does not reduce bacteria colonies. Also, if you are using kitchen waste, keep detergents, eggshells, bones, and onion scales out of the way, as these can adversely affect the operation of the biogas plant.

Biogas itself has a very unpleasant smell, but there is no smell when burning. If you burn gas without mixing with air, you will get a yellow flame with soot, which will easily smoke the bottom of the pan.

If biogas is mixed with air and then ignited, we get a pure blue flame without soot. So, for example, in factory gas stoves, the instructions say that when switching from main gas to bottled gas and vice versa, it is necessary to change jets (which differ in hole diameter), otherwise the burner will smoke. Alternatively, you can use laboratory bunsen burner.

If you do not have a laboratory burner available, then it is easy to make it from a piece of pipe by drilling holes at the base. Thus, the gas passing through the pipe will mix with air, and at the outlet of the pipe we will get a mixed gas.

As jets, you can experiment with pieces of wood by sharpening them under a pencil and drilling holes of different diameters in them. In this way, the optimal flame size can be obtained.

For the experiment, an old barbecue was used as a stove, in the bottom of which a hole was cut and a Bunsen burner was installed. And later, the barbecue was replaced with a single-burner stove.

To create gas pressure, a weight is placed on the collector (a small barrel for collecting gas). For example, if you install a load of 5 kg, then 1 liter of water can be boiled in 15 minutes. If you install a load of 10 kg, then 1 liter of water will boil in 10 minutes.

Summing up, it should be noted that homemade biogas plant produces biogas for 30 minutes of burner operation per day, if the raw material is manure. If, however, kitchen leftovers are used as raw materials, then the productivity is only 15 minutes per day.

The emitted gas is not so much, but you must admit that the biogas plant is not so big either. Therefore, if you want to increase the amount of gas produced, you will need to increase the reactor and collector volumes.

The dimensions of the collector may not be increased if you pump the biogas into another container (for example, into a cylinder) in a timely manner. Most simply, this can be done with a compressor from a refrigerator, which has one inlet and one outlet. We connect the input to the collector, and the output to the cylinder.

The compressor can be equipped with automation, for example, when the collector is filled with gas, the barrel rises, closes the contacts, thereby turning on the compressor. And the compressor, in turn, turned off when the barrel dropped to the minimum level.

Biogas plant reactor must be made of plastic, but, in no case from metal, because due to oxidative processes, the metal will quickly rust. Alternatively, you can use plastic barrels of large volumes (for example, eurocube). And so that large volumes of barrels do not take up much space in the yard, they can be buried.

Nov 19, 2016 Gennady