The Biogas Backpack is a pillow shaped balloon from flexible, gas tight material, plastic sheet and fabric. The two inner layers are made of gas tight PE-sheet, welded at the two open ends and equipped with a welded, threaded flange, holding a mini ball valve. The backpack is filled with biogas from the biogas plant by simple pressure equalization instead of by pump or compressor. It therefore does not need to be equipped with a security valve to release gas in the case of over-pressure.
To use the Biogas Backpack efficiently, it would make sense to produce the biogas in one central, technically-advanced biogas plant. This way, farmers in the surrounding areas can contribute to the biogas production by selling substrate to the plant owner in exchange for biogas and fertilizer.
Because of the limited amount of biogas, the high content (30-60%) of non-flammable CO² in biogas and the non-pressurized status of the gas, there is no risk of an explosion. Even if in contact with open fire, the backpack does not explode, but rather burns down in a controlled manner. To avoid accidents with leaking gas, the backpack is designed to be stored outside the house.
Combustible materials which are used for cooking, such as firewood and charcoal, are associated with a range of problems in many countries. Gathering these materials is time-consuming and difficult, also, because they are often in short supply. In addition, cooking with these materials can cause significant health problems. Replacing wood fuels, biogas can alleviate such problems while simultaneously reducing deforestation and soil erosion. However, once produced in biogas digesters it is very difficult to transport the gas to the respective households.
The Biogas Backpack aims to provide poor rural households with an affordable source of energy for lighting or cooking, thereby improving living conditions. Helping to avoid the time consuming task of collecting fuel wood, the biogas backpack helps to ease the daily work of women in developing countries. In addition, health risks can be minimized as burning biogas is nearly smokeless.
This solution was developed in order to facilitate the sale of biogas in developing countries and therefore makes it possible to start a business.