What is biogas?

Biogas is a naturally produced gas which contains one component that is flammable: Methane. Because of its methane content the gas can be used for energy generation, e.g. cooking, lighting, cooling or electricity generation.

It is produced from organic matter by bacteria under anaerobic conditions.


What does (B)energy do?

(B)energy is a social business that provides mobile biogas technology worldwide, especially in countries where firewood and charcoal are used as cooking fuel. By offering a unique combination of simple biogas digesters and light-weight biogas backpacks we enable biogas systems to be run as an income generating business for private individuals. These systems are offered to the end user through/or local partners.

Which components does the (B)energy system consist of?

The (B)energy system consists of three components: in the (B)plant the gas is produced, then it flows to the (B)pack, the storage and transport bag for biogas, from where it is used to supply biogas cooking appliances like the (B)flame biogas stove.

Are components of the (B)energy system available in my country?

We have representatives in a growing number of countries. Currently, the (B)energy system is manufactured in Germany and imported by our local importers and agents. Some importers are pursuing local manufacturing. Please contact (B)energy to find out whether there is an already existing distributor/installer established in your country.

Do end-users need to be literate?

Literacy by end-users is not necessary. Responsible for installation are local installers who have been trained to do the technical installation and to train the user. In case of problems the end user can always communicate with the installer.

What is the lifespan of a (B)energy system?

The (B)plant is a plastic bag that is not stressed by high pressure and does not have any moveable parts. Therefore, the system has a high durability of easily 10 years. However, this strongly relies on protection from UV-light. The user has to carefully protect the system from sunlight that contains the destructive UV radiation within the greenhouse.


How does the (B)plant work?

The principle of our biogas digesters is a plug flow system. We are feeding from one side and this ”plug” (the daily amount of substrate) is pushed from the inlet side during 30 days towards the outlet side and then exits the digester when it is fully digested.

This means the fresh material is not mixed with the already digested substrate and also the bacteria, which have different tasks, are not mixed. In general, this kind of system is more robust towards different amounts and kinds of substrate and also towards irregular feeding. Even if there is a scum-formation it can easily be broken by pushing the flexible material of the digester. This way even hard material can be mixed in again and the digester continues working also after a long idle time.

The greenhouse around the system helps to heat up the content to above 30 °C during the day, but at night the system will cool down and produce less/no gas. This system does not store gas inside the digester, but in an external storage bag.

The whole system is easily installed, emptied and moved.

Disadvantage: The pressure is not sufficient for lighting, unless the backpack is loaded with a very heavy weight of about 50 kg.


What is the ideal location for a household biogas plant?

The ideal location has the following characteristics:

  • Sunlight all day
  • Slipstream
  • Be level ground, without stones/roots
  • Next to the substrate with which the plant is fed
  • Easy access and possible removal of digestate

How far apart may the biogas plant, storage bag and digester be?

Long distances are possible here, because although the gas comes out of the plant at low pressure, it only has to move on its way to the storage bag. I.e. up to 200 m is no problem.

To cook, you then need a little more pressure. Here you can say that the further the route, the greater the weight on the rucksack. Up to 20 minutes is very easy to manage and if it has to be over 100m, then you can integrate a small gas pump.

We recommend using the gas line with an inner diameter of 16mm from our product catalogue, then the pressure losses are very low and everything is safe.

Who instals (B)plants?

(B)plants are installed by independent entrepreneurs, the installers who run a flexible business of installing and maintaining the (B)energy system. They are responsible to get together installation material, do the installation, train the user and settle payments for consumers.


Is the (B)plant safe?

The (B)plant is safe as it has been designed with a pressure relief valve through the connection of a water trap. The water trap, whose primary purpose is to collect condensed water from the system, is also able to release pressure. If in any case the pressure in the system is too high, the biogas can escape though the water trap.

What maintenance is required?

The greenhouse plastic is the major maintenance requirement. The plastic cover that protects the (B)plant from direct sunlight has to be maintained well. Depending on altitude and sunshine hours the cover will have to be replaced every 3-5 years. We recommend that you purchase the cover from (B)energy as it is especially UV-resistant.

How long can biogas be stored in the biogas backpack or storage bag?

The diffusion of biogas and/or air through the membrane is very low, but no membrane is completely tight. We recommend a storage period of max. 4 weeks to avoid gas losses and to prevent the diffusion of oxygen.


Which substrate can be used to feed the (B)plant?

The (B)plant can process anything organic. 

Yes: Cow manure and other animal manures, even human faeces, kitchen waste including peel of fruits and vegetables, food left-overs, old fat, meat, bread. 

No: The bacteria cannot process substrates that contain a lot of lignin, such as wood, husks, straw. Also not suitable are egg shells, bones, maize cobs and of course any plastic, glass, metal.

How is the substrate prepared?

Substrates are mixed with water in the inlet drum to avoid system blockage. The ratio of water to substrate is usually 1:1. The aim is to get a porridge-like consistency. The mixture should not be too thick, this will block the digester in the long-term.

How much substrate can be fed to the (B)plant?

The total daily input of animal dung for each available size of our (B)plants is 60L, 90L, 120L for (B)brave, (B)best, (B)clever respectively. In case of fresh matter like kitchen waste, the daily inputs will be reduced by 30%. At cold times the input amount also needs to be reduced.


What are the outputs of a (B)plant?

The two products biogas and bioslurry are naturally produced by bacteria under oxygen-free (anaerobic) conditions. The main component of biogas is methane, which is flammable and can be used for cooking or sold using available (B)packs to other people in the community.

Bioslurry is a nutritious organic fertiliser that can either be applied directly to crops in its liquid form or composted with rougher organic matter to form a more solid organic fertiliser.

How much biogas can be produced?

How much biogas your system can produce depends on the kind and amount of input substrate that you feed to your digester.

In the table below you see the different gas/methane potentials of organic wastes.

One backpack holds 1.000 L of biogas and lasts for 2-4 h of cooking.

oDM (organic dry matter) = the part of the substrate that is available for gas production
l/kg oDM = methane production in liters per kg of organic dry matter (this is mainly used in research, because the exact oDM is usually not known)
l/kg fresh matter = methane production in liters per kg of fresh matter (this is what you can use to calculate the approximate biogas production of a certain amount of substrate.

How can the bioslurry be collected?

Bioslurry can be collected using two ways, depending on the digester size and soil type. Either a bucket, similar to what is used for the inlet can be used to let the bioslurry overflow into directly from the digester, or a hole in the ground can be excavated. Using a hole in the ground, however, is only recommended in cases of heavy soil to prevent leaching and should optimally be protected from direct sunlight to reduce nutrient losses.

How much liquid fertiliser does the plant produce?

The input consists of organic residues and water. The water is only used to exchange the individual fermentation products among the bacteria. It is not degraded in the process and comes out completely.

60% of the organic matter, on the other hand, is converted into gas and water, i.e. a reduction of the mass takes place here. Since even the substrate consists mainly of water, the loss of volume is so low that one can roughly say: of the 100% that is fed, about 95% comes out again.


How can biogas be used for cooking?

Biogas is thanks to the methane content a flammable gas. It burns with a clean blue flame without smoke and without unhealthy emissions. The (B)flame is just a burner. It is provided to our importers and end customers as an assembly kit without a pot frame. The assembly and the design and manufacturing of the pot frame is done by our local partners. If you are an end customer buying our products, then you can design your own frame and get it made locally.

Can the burner size be adapted to different pot sizes?

The (B)flame can be modified to the individual needs and with its modular design it is very flexible in its applications. The burner size can be adapted to different pot sizes and the burner can be used as a free-standing burner combined with 3 stones or more advances it can be attached to different types of pot rests. This facilitates to adapt the (B)flame to different cultural cooking habits and the use of different pot sizes with one set-up.

Can the (B)flame be used as a multi-burner?

Yes, you can have several (B)flames in series or parallel, so that you can cook on more than one flame at a time. It depends on the set-up of your frame. Our installer will be happy to provide a solution locally.


What is the purpose of the (B)pack?

The (B)pack is a biogas storage bag to store and transport biogas. Its purpose is to facilitate the sale of biogas in locations where people still cook on firewood and charcoal. The (B)pack is filled with biogas through pressure equalisation with any biogas digester. For cooking, the (B)pack is connected to a biogas stove via a flexible pipe/hose.


How does (B)energy provide customer service

We have developed a mobile application that our installers use during the installation. If there is any problem with a biogas system the installer will take care of maintenance and repair and if necessary he is guided in the process by (B)energy.

Is the (B)app available in different languages?

As (B)energy is working in countries worldwide, we are working together with our local partners on translating it into all the different languages. So far, the app is available in English, French and the Amharic (Ethiopia) version is almost finalised. If you want a specific language to be available next to already listed languages, please get in touch with us and we would be very happy to include you in making it possible ASAP!


How much does a (B)energy system cost?

Costs depend on (B)plant sizes and need for additional components. A full price list is available on request or from your local distributor.

Which sizes of (B)energy systems are available?

There are three different sizes available as standard sizes. Custom made digesters up to 15.000 L (15 m3) can be offered on request. A newly developed city household digester is currently underway and will soon be offered as well.

How to calculate the size of the biogas system needed?

To calculate the size of a digester you have to know the kind and amount of

substrate that will be available to feed the digester.

HRT of cow dung should be at least 30 days (in (B)energy system). If a farmer has 50 kg of cow dung per day he will have in total 50 kg of Cow dung + 50 kg of water = 100 kg of input substrate (roughly 100 L).

Capacity of digester = 35 days x 100 L/day = 3.500 L (size of digester)

Which components are included in a delivery?

Materials included in the delivery are the digester, respective number of storage bags (B)packs and burners (B)flames with ball valves, the greenhouse cover and a tank connection of 110 mm.

Why is not everything included?

To reduce the import cost the (B)energy system is optimized to maximum use of locally available material. Materials that are not delivered are available on the local market. Our installer will take care of this for you. If you are an end customer ordering directly from (B)energy then we will provide you a list of material.

Which materials are not delivered?

Additional materials which need to be obtained in the respective country are PVC pipes, HDPE pipe, fittings, hoses, rope and drum/bucket – with detailed description upon purchase of a system.

What is the weight of a complete (B)energy package?

The weight of a (B)energy package depends on the size of the ordered system:

·       (B)clever: 31.5 kg

·       (B)best: 25 kg

·       (B)brave: 18 kg

·       size of the cardboard box: max. 60 x 32 x 120 cm

What are the customs tariff numbers?

The customs tariff number for available (B)energy system components and greenhouse cover are:

·       (B)plant: Customs Tariff number: 39269092, HS code: 392690

·       (B)pack: Customs Tariff number: 63053390, Hs code: 630533

·       (B)flame: Customs Tariff number: 73219000, HS code: 732190

·       Greenhouse cover: Customs Tariff number: 54072019, HS code: 540720

How high are import duties and taxes?

Import duties and taxes for each respective country can be found on the following website. All you need is to enter the destination country and HS code of the product.

Connect with us

Email: info(at)be-nrg(dot)com

Contact: +49 2620 902622