In times of crisis, every home owner strives to minimize their heating costs. For this, alternative energy sources are used. One of the new ones is the production of biogas, for the production of which ordinary manure is used. A biogas plant allows you to obtain it without much effort.

Installations for the production of biogas can be purchased from specialized companies. However, if you have a desire, you can create it on your own. The use of such equipment will allow save on energy, the cost of which only increases from year to year. When you have such an installation, you will be able to obtain and use cheap energy for your own purposes, which can be used, in particular, for heating your home.

Who needs installations?

This equipment is used to produce flammable gases from biological raw materials. They are needed everywhere where this type of fuel is used to generate heat and electricity. First of all, there is a need for them in farms where there is a large amount of biowaste. The use of such installations makes it possible to make production waste-free, and in addition to significantly increase its profitability.

In this case, costs are excluded for the purchase of thermal and electrical energy. Using equipment for producing biogas, livestock enterprises can recycle waste and generate electrical energy. Thermal energy obtained from biogas can be used to heat premises - not only residential, but also utility rooms. This type of fuel can also be used to generate electricity.

Using a biogas plant, you can generate electricity, the excess of which can be sold at market value, thereby turning manure into profit. It is especially beneficial to use such equipment for farmers who run large farms. They can purchase a ready-made station, which will produce biogas during operation. However, the cost of such equipment, which is produced in factories, is quite high. But by paying a lot of money, you get a reliable station that, subject to operating conditions, will serve for a long time.

If you do not want to spend a lot of money on purchasing a factory station, then you can spend your time and effort and build such an installation with your own hands. To create it, you need available materials, which ensures an acceptable cost of equipment for a station created on your own. The operation of a homemade installation will be no different from equipment manufactured at the factory. Another advantage of creating an installation yourself is that you don’t have to spend money on special tool. You can completely get by with the usual one, which any master has.

Principle of biogas formation

Those who have decided to create an installation for the production of biogas need to know about the technology of this energy source. The process of processing biological masses takes place in a special container. Anaerobic bacteria take an active part in it.

In order for the biogas production process to start, it is necessary to create certain conditions in it. The most important thing is in it there must be no air. In this case, the process of biomass fermentation occurs. Its duration largely depends on the amount of raw materials that are used to produce this fuel.

During the fermentation process, a gas mixture is formed. It includes:

• methane – 60%;
• acid gas – 35%.

The remaining gaseous components present in the mixture account for 5%.

This is how gas is formed, which is then removed from the reactor, undergoes a cleaning process. Upon completion, it can be used for its intended purpose.

Service Features

Waste subjected to such processing can then be used as good fertilizer. When producing biogas, they must be periodically removed from the bioreactor. You can put processed raw materials in fields with vegetable crops. You can create a biogas plant with your own hands without any problems if you are a farmer or have access to livestock enterprises. Biogas production will only be profitable if you have a source of supply of manure or other waste from livestock enterprises.

Creation of a bioreactor

Proper creation of a bioreactor is only possible if you know what parts does it consist of?.

Bioreactor device

The simplest design is taken as a basis. It does not provide for the presence of such components as:

• heating;
• device for mixing biomass.

The design includes a reactor, which is also known as a digester. Thanks to it, manure is processed. In addition, the bioreactor includes a bunker. It is used to load organic waste into the reactor. To make it convenient to add manure, you should install an entrance hatch in the design of this equipment. A water seal would also be a good idea. And in order to be able to unload waste raw materials, it is necessary to add a pipe to the structure. It will also be used for removing biogas from the plant.

Main works

Making such a design with your own hands is quite simple. Before starting work, you need to select a place on the site where you will create a bioreactor. A reinforced container will be manufactured there, the basis for the placement of which will be a concrete surface.

The vessel, which will be created subsequently, will act as a bioreactor. At the base of the installation holes must be provided, through which raw materials that have undergone the processing process will be removed. The hole must be made in such a way that it can be tightly closed. The need for this is due to the fact that the efficiency of the bioreactor for processing manure is ensured only under conditions of absolute tightness.

In order to correctly calculate the dimensions of a concrete workshop, it is necessary to take into account the amount of organic waste simultaneously used for processing. To do this, you need to find out before starting work how much raw material will appear on a farm or in a private farmstead every day. However, you should not save on the tank, since for the bioreactor to fully operate, it is necessary that the tank be filled to two-thirds of the available volume.

The simplest option for making a bioreactor is using a regular barrel. In this case, the installation will work according to the following principle:

When organic waste enters the bioreactor tank, which is located deep in the ground, the fermentation process begins. This leads to the release of biogas.

Features of container manufacturing

Biogas plants can be made in small volumes to process organic waste in small quantities. An excellent option would be to use not a reinforced concrete tank, but a steel container, which can be a barrel.

If you decide to use this option, then when choosing a metal product you need to consider the following points.

First of all, attention should pay attention to welds. They must be durable and ensure the tightness of the products. If you have chosen a small-capacity barrel to create a bioreactor, then you should not count on the fact that during its operation the amount of gas produced will be large. The energy output will largely depend on the mass of organic waste simultaneously processed in the reactor. Thus, in order to get 100 cubic meters. m of biogas, it is necessary to process manure in the amount of 1t.

DIY heating system in a biogas plant

A self-made biogas installation will be most effective in producing biogas if you equip it with heating. This will speed up the fermentation process of biomass. If the equipment is used in the southern regions, then no need for heating. Activation of fermentation processes is ensured by the outside air temperature.

However, if you live in an area with a cold climate, then using heating in winter will allow you to produce a fairly large amount of gas. You should know that at a fermentation temperature of 38 degrees Celsius, this process begins. Therefore, it is necessary to ensure that the temperature in the bunker does not fall below this mark. In this case, the biogas production process will take place in the bioreactor.

Methods for equipping the installation with heating

Install heating in the bioreactor possible in several ways.

If you use automated systems to organize heating, then the device will be turned on without your help when cold biomass enters the reactor. When the raw material warms up to the set temperature, the heating system will turn off.

To make a high-quality biogas plant with your own hands, it is necessary even before starting work prepare drawings, which must be taken into account when carrying out work. Heating elements can be installed in hot water boilers, so care must be taken to purchase the necessary gas equipment.

In order to increase the amount of biogas produced, in addition to heating, you can also equip your installation with a device for mixing biomass. To do this, you will have to spend some time and create a device that will work the same as a regular household mixer. It will be driven by a shaft. The latter must be brought out through the holes in the lid.

Output system design

When you build a biogas plant yourself, you cannot do without creating a biogas removal system. To do this, it is necessary to build a special hole into the equipment design. It is best to do it at the top of the lid. The latter should close the tank well. To prevent the produced biogas from mixing with air, it is necessary to remove the finished gas through a water seal.

Conclusion

If you are the owner of a farm, then you constantly generate a large amount of organic waste. Many people use them as fertilizer in the fields. However, they can be used to greater benefit for yourself. Manure can be used to produce heat and electricity. To do this, it is necessary to install a biogas plant. It processes manure and produces biogas. You can purchase it from specialized companies without any problems. However, the cost of such stations is quite high. To reduce your costs, you can arrange it yourself.

By processing manure and other organic waste with it, you can obtain fuel that can be used to heat your home, as well as premises where animals are kept. This will reduce the cost of their maintenance to a minimum and make production more profitable.

It’s not difficult to make biogas with your own hands, which even a beginner can handle perfectly. Anyone can create biogas on their own. This does not require special knowledge or special skills in the field of renewable energy sources. If every person thinks about the world around them, the environmental situation on Earth will improve significantly.

• • How to get gas from manure
  • Making biogas at home
  • Why do you need a biogas plant for farming?
  • Question for efficient farming: how to get methane correctly
  • DIY biogas plant (video)

Manure gas is a reality. It can actually be obtained from manure, which somehow fertilizes the land. But you can put it into circulation and get real gas.

To obtain gas from manure with your own hands at home, a farm biogas installation is used. You can produce natural gas using a digester right on the farm. This is how many farmers produce. You don't need to purchase special fuel for this. Enough natural raw materials.

The bioreactor should contain from 1 to 8-10 cubic meters. private production waste, chicken manure. 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 installation, you should find the drawings according to which the equipment is made, and you also need a diagram.

You can get biogas by using manure, which is used to fertilize the land.

The installation is carried out in several stages:

Mixing of raw materials;

Heating;

Biogas release.

A homemade installation will allow you to obtain gas from manure in a matter of time. You can assemble it yourself, having diagrams and drawings. For the heat generator, you can choose boilers for heating water. To collect gas on site, a gas tank is needed. It collects and stores gas.

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

You can obtain gas from manure using a biogas plant. You can design it yourself. Determine the volume of raw materials to be processed, select a suitable container in which the raw materials will be processed and mixed - this is how gas saturated with methane in biofuel is produced.

Making biogas at home

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

Biogas is a combination of various gases that are created by the decomposition of organic substances. It is worth knowing that biogas is flammable. It ignites easily with a clean flame.

The advantage of producing biogas at home is that it can be easily obtained without purchasing expensive equipment

Let us note the advantages of a biogas installation at home:

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

Having a biogas installation at home is a profitable business for the owner of a summer cottage. To make such an installation, you need a small amount of money: two 200-liter barrels, a 50-liter barrel, 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, taps, hoses and pipes can almost always be found on the farms of dacha owners. A 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, and owners of private houses do not see the need to build a biogas installation. At first glance, this is true. But then, when the owners see all the benefits, the question of the need for such an installation disappears.

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

Using your own energy costs less than paying to supply it to the farm.

Another main reason for the need to create an installation is the organization of a complete waste-free production cycle. We use manure or litter as raw materials for the device. After processing we get new gas.

Many farms are willing to use a biogas plant because it significantly saves energy and gas costs

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

3 advantages of a biogas plant:

• Generating energy to keep the family farm running;
• Organization of a complete cycle;
• Efficient use of raw materials.

Having an installation on your farm is an indicator of your efficiency and concern for the environment. Biogenerators save a huge amount of money, ensuring waste-free production, efficient distribution of resources and raw materials, but also your complete self-sufficiency.

Question for efficient farming: 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.

The production of methane is influenced by the environment, the quality of raw materials and other factors

Let us highlight the factors that influence methane production:

• Environment;
• High-quality raw materials;
• Frequency of mixing of raw materials in the installation tank.

The raw materials in the container should be mixed with a pitchfork 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 producing biogas, the better quality of biogas you will get 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. No emissions or pollution. Biogas plants solve this problem. In addition, the owner of the biogas plant personally receives direct monetary benefits from its use.

Among the important components of our lives, energy resources are of great importance, prices for which are rising almost every month. Every winter season makes a hole in family budgets, forcing them to incur heating costs, and therefore, fuel for stoves and heating boilers. But what to do, after all, electricity, gas, coal or firewood cost money, and the more remote our homes are from major energy highways, the more expensive heating will cost... Meanwhile, alternative heating, independent of any suppliers and tariffs, can be built on biogas, the extraction of which does not require geological exploration, well drilling, or expensive pumping equipment.

Biogas can be obtained in almost home conditions, while incurring minimal, quickly recouping costs - most of the answers on this issue are contained in this article.

Biogas heating - history

Interest in flammable gas formed in swamps during the warm season of the year arose among our distant ancestors - advanced cultures of India, China, Persia and Assyria experimented with biogas over 3 thousand years ago. In the same ancient times, in tribal Europe, the Alemanni Swabians noticed that the gas released in the swamps burned well - they used it to heat their huts, supplying gas to them through leather pipes and burning them in the hearths. The Swabians considered biogas to be the “breath of dragons,” which they believed lived in swamps.

Centuries and millennia later, biogas experienced its second discovery - in the 17th and 18th centuries, two European scientists immediately paid attention to it. The famous chemist of his time, Jan Baptista van Helmont, established that the decomposition of any biomass produces a flammable gas, and the famous physicist and chemist Alessandro Volta established a direct relationship between the amount of biomass in which decomposition processes take place and the amount of biogas released. In 1804, the English chemist John Dalton discovered the formula for methane, and four years later the Englishman Humphry Davy discovered it as part of swamp gas. Interest in the practical use of biogas arose with the development of gas street lighting - at the end of the 19th century, the streets of one district of the English city of Exeter were illuminated gas obtained from the wastewater collector.

In the 20th century, energy demands caused by World War II forced Europeans to look for alternative energy sources. Biogas plants, in which gas was produced from manure, spread in Germany and France, and partly in Eastern Europe. However, after the victory of the countries of the anti-Hitler coalition, biogas was forgotten - electricity, natural gas and petroleum products completely covered the needs of industries and the population.

Today, the attitude towards alternative energy sources has changed dramatically - they have become interesting, since the cost of conventional energy resources increases from year to year. At its core, biogas is a real way to avoid tariffs and costs for classical energy sources, to get your own source of fuel, for any purpose and in sufficient quantities.

The largest number of biogas plants have been created and operated in China: 40 million plants of medium and low power, the volume of methane produced is about 27 billion m3 per year.

Biogas - what is it

This is a gas mixture consisting mainly of methane (content from 50 to 85%), carbon dioxide (content from 15 to 50%) and other gases in much smaller percentages. Biogas is produced by a team of three types of bacteria that feed on biomass - hydrolysis bacteria, which produce food for acid-forming bacteria, which in turn provide food for methane-producing bacteria, which form biogas.

Fermentation of the original organic material (for example, manure), the product of which will be biogas, takes place without access to an external atmosphere and is called anaerobic. Another product of such fermentation, called compost humus, is well known to rural residents who use it to fertilize fields and vegetable gardens, but the biogas and thermal energy produced in compost heaps are usually not used - and in vain!

What factors determine the yield of biogas with a higher methane content?

First of all, it depends on the temperature. The higher the temperature of their environment, the higher the activity of bacteria fermenting organic matter; at sub-zero temperatures, fermentation slows down or stops completely. For this reason, biogas production is most common in countries in Africa and Asia, located in the subtropics and tropics. In the Russian climate, the production of biogas and a complete transition to it as an alternative fuel will require thermal insulation of the bioreactor and the introduction of warm water into the mass of organic matter when the temperature of the external atmosphere drops below zero. The organic material placed in the bioreactor must be biodegradable, it is required to introduce it contains a significant amount of water - up to 90% of the mass of organic matter. An important point will be the neutrality of the organic environment, the absence in its composition of components that prevent the development of bacteria, such as cleaning and detergents, and any antibiotics. Biogas can be obtained from almost any waste of economic and plant origin, wastewater, manure, etc.

The process of anaerobic fermentation of organic matter works best when the pH value is in the range of 6.8-8.0 - high acidity will slow down the formation of biogas, because the bacteria will be busy consuming acids and producing carbon dioxide, which neutralizes the acidity.

The ratio of nitrogen and carbon in the bioreactor must be calculated as 1 to 30 - in this case, the bacteria will receive the amount of carbon dioxide they need, and the methane content in the biogas will be the highest.

The best yield of biogas with a sufficiently high methane content is achieved if the temperature in the fermentable organic matter is in the range of 32-35 ° C; at lower and higher temperatures, the content of carbon dioxide in the biogas increases and its quality decreases. Bacteria that produce methane are divided into three groups: psychrophilic, effective at temperatures from +5 to +20 ° C; mesophilic, their temperature range is from +30 to +42 °C; thermophilic, operating in the mode from +54 to +56 °C. For the biogas consumer, mesophilic and thermophilic bacteria, which ferment organic matter with a higher gas yield, are of greatest interest.

Mesophilic fermentation is less sensitive to temperature changes of a couple of degrees from the optimal temperature range and requires less energy to heat organic material in the bioreactor. Its disadvantages, compared to thermophilic fermentation, are lower gas output, a longer period of complete processing of the organic substrate (about 25 days), and the resulting decomposed organic material may contain harmful flora, because the low temperature in the bioreactor does not ensure 100% sterility.

Raising and maintaining the intra-reactor temperature at a level acceptable for thermophilic bacteria will ensure the greatest yield of biogas, complete fermentation of organic matter will take place in 12 days, the decomposition products of the organic substrate are completely sterile. Negative characteristics: a change in temperature by 2 degrees outside the range acceptable for thermophilic bacteria will reduce gas yield; high need for heating, as a result - significant energy costs.

The contents of the bioreactor must be stirred twice a day, otherwise a crust will form on its surface, creating a barrier to biogas. In addition to eliminating it, stirring allows you to equalize the temperature and acidity level inside the organic mass. In continuous-cycle bioreactors, the highest biogas yield occurs with the simultaneous unloading of organic matter that has undergone fermentation and the loading of a volume of new organic matter in an amount equal to the unloaded volume. In small-volume bioreactors, the kind that are usually used in dacha farms, every day it is necessary to extract and introduce organic matter in a volume approximately equal to 5% of the internal volume of the fermentation chamber.

The yield of biogas directly depends on the type of organic substrate placed in the bioreactor (the average data per kg of dry substrate weight is given below):

1. horse manure produces 0.27 m3 of biogas, methane content 57%;
2. cattle manure produces 0.3 m3 of biogas, methane content 65%;
3. fresh cattle manure produces 0.05 m3 of biogas with 68% methane content;
4. chicken manure - 0.5 m3, the methane content in it will be 60%;
5. pork manure - 0.57 m3, the share of methane will be 70%;
6. sheep manure - 0.6 m3 with a methane content of 70%;
7. wheat straw - 0.27 m3, with 58% methane content;
8. corn straw - 0.45 m3, methane content 58%;
9. grass - 0.55 m3, with 70% methane content;
10. wood foliage - 0.27 m3, methane share 58%;
11. fat - 1.3 m3, methane content 88%.

Biogas plants

These devices consist of the following main elements - a reactor, an organic loading hopper, a biogas outlet, and a fermented organic matter unloading hopper.

According to the type of design, biogas plants are of the following types:

• without heating and without stirring the fermented organic matter in the reactor;
• without heating, but with stirring of the organic mass;
• with heating and stirring;
• with heating, with stirring and with devices that allow you to control and manage the fermentation process.

The first type of biogas plant is suitable for a small farm and is designed for psychrophilic bacteria: the internal volume of the bioreactor is 1-10 m3 (processing 50-200 kg of manure per day), minimal equipment, the resulting biogas is not stored - it immediately goes to the household appliances that consume it. This installation can only be used in southern regions; it is designed for an internal temperature of 5-20 ° C.

Removal of fermented (fermented) organic matter is carried out simultaneously with the loading of a new batch; the shipment is carried out into a container, the volume of which must be equal to or greater than the internal volume of the bioreactor. The contents of the container are stored in it until introduced into the fertilized soil. The design of the second type is also designed for small farms; its productivity is slightly higher than the biogas plants of the first type - it is equipped with a mixing device with a manual or mechanical drive.

The third type of biogas plants is equipped, in addition to the mixing device, with forced heating of the bioreactor; the hot water boiler runs on alternative fuel produced by the biogas plant. Methane production in such installations is carried out by mesophilic and thermophilic bacteria, depending on the heating intensity and temperature level in the reactor.

The last type of biogas plants is the most complex and is designed for several consumers of biogas; the design of the plants includes an electric contact pressure gauge, a safety valve, a hot water boiler, a compressor (pneumatic mixing of organic matter), a receiver, a gas tank, a gas reducer, and an outlet for loading biogas into transport. These installations operate continuously, allow the setting of any of three temperature conditions thanks to precisely adjustable heating, and biogas selection is carried out automatically.

DIY biogas plant

The calorific value of biogas produced in biogas plants is approximately 5,500 kcal/m3, which is slightly lower than the calorific value of natural gas (7,000 kcal/m3). To heat 50 m2 of a residential building and use a four-burner gas stove for an hour, an average of 4 m3 of biogas will be required.

Industrial biogas production plants offered on the Russian market cost from 200,000 rubles. - despite their apparently high cost, it is worth noting that these installations are precisely calculated according to the volume of loaded organic substrate and are covered by manufacturer’s warranties.

If you prefer to create a biogas plant yourself, then further information is for you!

Bioreactor form

The best shape for it would be oval (egg-shaped), but building such a reactor is extremely difficult. A cylindrical bioreactor, the upper and lower parts of which are made in the form of a cone or semicircle, will be easier to design. Square or rectangular reactors made of brick or concrete will be ineffective because... Over time, cracks will form in the corners in them, caused by the pressure of the substrate; hardened fragments of organic matter will accumulate in the corners, interfering with the fermentation process. Steel tanks of bioreactors are airtight, resistant to high pressure, and they are not so difficult to build. Their disadvantage is their poor resistance to rust; they require a protective coating, for example, resin, to be applied to the inner walls. The outside surface of the steel bioreactor must be thoroughly cleaned and painted in two layers.

Bioreactor containers made of concrete, brick or stone must be carefully coated on the inside with a layer of resin that can ensure their effective water and gas impermeability, withstand temperatures of about 60 ° C, and the aggression of hydrogen sulfide and organic acids. In addition to resin, to protect the internal surfaces of the reactor, you can use paraffin, diluted with 4% motor oil (new) or kerosene and heated to 120-150 ° C - the surfaces of the bioreactor must be heated with a burner before applying a paraffin layer to them.

When creating a bioreactor, you can use plastic containers that are not susceptible to rust, but only hard plastic with sufficiently strong walls. Soft plastic can only be used in the warm season, because... With the onset of cold weather, it will be difficult to attach insulation to it, and its walls are not strong enough. Plastic bioreactors can only be used for psychrophilic fermentation of organic matter.

Bioreactor location

Its placement is planned depending on the available space on a given site, sufficient distance from residential buildings, distance from the waste disposal site, from animal placement sites, etc. Planning a ground-based, fully or partially submerged bioreactor depends on the groundwater level, the convenience of introducing and removing the organic substrate into the reactor tank. It would be optimal to place the reactor vessel below ground level - savings are achieved on equipment for introducing an organic substrate into the reactor tank, thermal insulation is significantly increased, for which inexpensive materials (straw, clay) can be used.

Bioreactor equipment

The reactor tank must be equipped with a hatch, which can be used to carry out repair and maintenance work. It is necessary to lay a rubber gasket or a layer of sealant between the bioreactor body and the hatch cover. It is optional, but extremely convenient, to equip the bioreactor with a sensor for temperature, internal pressure and organic substrate level.

Bioreactor thermal insulation

Its absence will not allow the biogas plant to be operated all year round, only during the warmer months. To insulate a buried or semi-buried bioreactor, clay, straw, dry manure and slag are used. The insulation is laid in layers - when installing a buried reactor, the pit is covered with a layer of PVC film, which prevents direct contact of the heat-insulating material with the soil. Before installing the bioreactor, straw is poured onto the bottom of the pit with a PVC film laid, a layer of clay is placed on top of it, then the bioreactor is placed. After this, all free areas between the reactor tank and the foundation pit lined with PVC film are filled with straw almost to the end of the tank, and a layer of clay mixed with slag is poured on top of a 300 mm layer.

Loading and unloading organic substrate

The diameter of the pipes for loading into and unloading from the bioreactor must be at least 300 mm, otherwise they will clog. In order to maintain anaerobic conditions inside the reactor, each of these pipes should be equipped with screw or half-turn valves. The volume of the bunker for supplying organic matter, depending on the type of biogas plant, should be equal to the daily volume of input raw materials. The feed hopper should be located on the sunny side of the bioreactor, because this will help to increase the temperature in the introduced organic substrate, accelerating the fermentation processes. If the biogas plant is connected directly to the farm, then the bunker should be placed under its structure so that the organic substrate enters it under the influence of gravity.

The pipelines for loading and unloading the organic substrate should be located on opposite sides of the bioreactor - in this case, the input raw materials will be distributed evenly, and the fermented organic matter will be easily removed under the influence of gravitational forces and the mass of the fresh substrate. Holes and installation of the pipeline for loading and unloading organic matter should be completed before installing the bioreactor at the installation site and before placing layers of thermal insulation on it. The tightness of the internal volume of the bioreactor is achieved by the fact that the inputs of the substrate loading and unloading pipes are located at an acute angle, while the liquid level inside the reactor is higher than the pipe entry points - a hydraulic seal blocks the access of air.

It is easiest to introduce new and remove fermented organic material using the overflow principle, i.e. a rise in the level of organic matter inside the reactor when a new portion is introduced will remove the substrate through the unloading pipe in a volume equal to the volume of the introduced material.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Required mandatory materials:

• two containers;
• connecting pipes;
• valves;
• gas filter;
• means of ensuring tightness (glue, resin, sealant, etc.);

Desirable:

• stirrer with electric motor;
• temperature sensor;
• pressure meter;

The sequence below is suitable for the southern regions. For operation under any conditions, a reactor heating system should be added, which will ensure heating of the vessel to 40 degrees Celsius and increase thermal insulation, for example, by enclosing the structure with a greenhouse. It is advisable to cover the greenhouse with black film. It is also advisable to add a condensate drainage device to the pipeline.

Creating a simple biogas plant:

1. Create a storage container. We select a tank where the resulting biogas will be stored. The reservoir is fixed with a valve and equipped with a pressure gauge. If gas consumption is constant, then there is no need for a gas tank.
2. Insulate the structure inside the pit.
3. Install pipes. Lay pipes into the pit for loading raw materials and unloading compost humus. An inlet and outlet hole are made in the reactor tank. The reactor is placed in a pit. Pipes are connected to the holes. The pipes are tightly secured using glue or other suitable means. Pipe diameters less than 30 cm will contribute to their clogging. The loading location should be chosen on the sunny side.
4. Install the hatch. The rector, equipped with a hatch, makes repair and maintenance work more convenient. The hatch and reactor vessel should be sealed with rubber. You can also install temperature, pressure and raw material level sensors.
5. Select a container for the bioreactor. The selected container must be durable - since fermentation releases a large amount of energy; have good thermal insulation; be air and waterproof. Egg-shaped vessels are best suited. If building such a reactor is problematic, then a cylindrical vessel with rounded edges would be a good alternative. Square-shaped containers are less efficient because hardened biomass will accumulate in the corners, making fermentation difficult.
6. Prepare the pit.
7. Select a location for mounting the future installation. It is advisable to choose a place far enough from the house and so that you can dig a hole. Placing it inside a pit allows you to significantly save on thermal insulation, using cheap materials like clay.
8. Check the tightness of the resulting structure.
9. Start the system.
10. Add raw materials. We wait about two weeks until all the necessary processes take place. A necessary condition for gas combustion is to get rid of carbon dioxide. A regular filter from a hardware store will do for this. A homemade filter is made from a 30 cm long piece of gas pipe filled with dry wood and metal shavings.

Composition and types

Biogas is a gas obtained as a result of a three-phase biochemical process on biomass, taking place in sealed conditions.

The process of biomass decomposition is sequential: first it is exposed to hydrolytic bacteria, then acid-forming bacteria and finally methane-forming bacteria. The material for microorganisms at each stage is the product of the activity of the previous stage.

At the output, the approximate composition of biogas looks like this:

• methane (50 to 70%);
• carbon dioxide (30 to 40%);
• hydrogen sulfide (~2%);
• hydrogen (~1%);
• ammonia (~1%);

The accuracy of the proportions is affected by the raw materials used and gas production technology. Methane has the potential for combustion; the higher its percentage, the better.

Ancient cultures dating back more than three thousand years (India, Persia or Assyria) have experience using flammable swamp gas. The scientific basis was formed much later. The chemical formula of methane CH 4 was discovered by scientist John Dalton, and the presence of methane in swamp gas was discovered by Humphry Davy. The Second World War played a major role in the development of the alternative energy industry, requiring the warring parties to have a huge need for energy resources.

The USSR's possession of huge reserves of oil and natural gas led to a lack of demand for other energy production technologies; the study of biogas was mainly a subject of interest to academic science. At the moment, the situation has changed so much that, in addition to the industrial production of various types of fuel, anyone can create a biogas plant for their own purposes.

Installation device

– a set of equipment designed to produce biogas from organic raw materials.

Based on the type of raw material supplied, the following types of biogas plants are distinguished:

• with portioned feeding;
• with continuous feed;

Biogas plants with a constant supply of raw materials are more efficient.

By type of raw material processing:

1. No automatic stirring raw materials and maintaining the required temperature - complexes with minimal equipment, suitable for small farms (Diagram 1).
2. With automatic stirring, but without maintaining the required temperature - also serves small farms, more efficiently than the previous type.
3. With support for the required temperature, but without automatic mixing.
4. With automatic mixing of raw materials and temperature support.

Principle of operation

The process of converting organic raw materials into biogas is called fermentation. The raw materials are loaded into a special container that provides reliable protection of the biomass from oxygen. An event that occurs without the intervention of oxygen is called anaerobic.

Under the influence of special bacteria, fermentation begins to occur in an anaerobic environment. As fermentation progresses, the raw material becomes covered with a crust, which must be destroyed regularly. Destruction is carried out by thorough mixing.

It is necessary to mix the contents at least twice a day, without violating the tightness of the process. In addition to removing the crust, stirring allows you to evenly distribute acidity and temperature inside the organic mass. As a result of these manipulations, biogas is produced.

The resulting gas is collected in a gas tank and from there it is delivered to the consumer through pipes. Biofertilizers obtained after processing the feedstock can be used as a food additive for animals or added to the soil. This fertilizer is called compost humus.

The biogas plant includes the following elements:

• homogenization tank;
• reactor;
• stirrers;
• storage tank (gas-holder);
• heating and water mixing complex;
• gas complex;
• pump complex;
• separator;
• control sensors;
• Instrumentation and automation with visualization;
• safety system;

An example of an industrial-type biogas plant is shown in Diagram 2.

Raw materials used

The decomposition of any animal or plant matter will release flammable gas to varying degrees. Mixtures of various compositions are well suited for raw materials: manure, straw, grass, various wastes, etc. The chemical reaction requires a humidity of 70%, so the raw material must be diluted with water.

The presence of cleaning agents, chlorine, and washing powders in organic biomass is unacceptable, as they interfere with chemical reactions and can damage the reactor. Also not suitable for the reactor are raw materials with sawdust from coniferous trees (containing resins), with a high proportion of lignin and exceeding the moisture threshold of 94%.

Vegetable. Plant raw materials are excellent for biogas production. Fresh grass gives the maximum fuel yield - about 250 m 3 of gas with a methane share of 70% is obtained from a ton of raw material. Corn silage is slightly smaller – 220 m3. Beet tops – 180 m3.

Almost any plant, hay or algae can be used as biomass. The disadvantage of application is the length of the production cycle. The process of obtaining biogas takes up to two months. The raw materials must be finely ground.

Animal. Waste from processing plants, dairy plants, slaughterhouses, etc. Suitable for biogas plant. The maximum fuel yield is provided by animal fats - 1500 m 3 of biogas with a methane share of 87%. The main disadvantage is shortage. Animal raw materials must also be ground.

Excrement. The main advantage of manure is its cheapness and easy availability. Disadvantage – the quantity and quality of biogas is lower than from other types of raw materials. Horse and cow excrement can be processed immediately. The production cycle will take approximately two weeks and will produce an output of 60 m3 with 60% methane content.

Chicken manure and pig manure cannot be used directly because they are toxic. To start the fermentation process, they must be mixed with silage. Human waste products can also be used, but sewage is not suitable since the fecal content is low.

Schemes of work

Scheme 1 – biogas plant without automatic mixing of raw materials:

Scheme 2 – industrial biogas plant:

Finally, here is a list of useful information that will help you avoid additional problems when creating a biogas plant:

1. Practice says that to heat a living space with an area of ​​50 m2, it is necessary to consume 3.5 m3 of gas per hour.
2. It is not advisable to use biogas directly for cooking, because the taste may change.
3. It is necessary to avoid getting solid objects (nuts, bolts, etc.) into the raw materials, because the equipment may deteriorate.

In order for biogas to burn stably, it must meet certain standards:

• methane content at least 65% (optimal content from 90 to 95%);
• there should be no water vapor, hydrogen and carbon dioxide;
• normal gas supply pressure 12.5 bar;

If the gas goes out due to a pressure surge or for other reasons, and its supply continues, it can lead to tragic consequences. Therefore, modern equipment with gas monitoring sensors should be used.