Biogas Digester


Biogas is a clean, renewable energy obtained from biodegradable organic material as kitchen waste and animal manure. The feedstock is added daily into a hermetically insulated bag, the digester. There, in the absence of oxygen, anaerobic bacteria degrade the organic matter to multiply and produce biogas and bioslurry, an efficient natural fertilizer.

The most common type of reactor installed is the fixed dome digester, widely used in China and India. Its installation requires skilled technical expertise and complex logistics, making installation expensive and time-consuming especially for rural areas. Moreover, a lot of plants constructed by the government in Indonesia are now abandoned due to a bad follow-up strategy, an inefficient technology and a discontinuous source of feedstock.

OUR MISSION aims to introduce the digester to reduce usage of fossil fuel, achieve a closed cycle of material and especially alleviate energy poverty. Indeed, our aim it is not only to use biogas to produce combustible gas but use if for other further activities connected to agriculture: since fossil fuels in Indonesia are highly subsidised, focusing only on biogas production as substitute of LPG or kerosene is not reasonable solution, economically speaking, for farmers. For this reason, our aim is to link the biogas solution to sustainable commercial activities such as roasting coffee, drying crops and all kind of post-harvesting processes or food production. Such solutions could generate additional income for the farmers, create job opportunities and generally improve their well-being.


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The biogas bag developed by is easy to be transported to remote areas with poor electricity access and where energy is expensive due to logistics costs.

The PVC bio-digester bag is a plug flow tubular technology with cylindric shape that leads to longitudinal flow of the substrate with efficient anaerobic degradation. As shown in the table below, the bag is made with PVC 550, a material which is resistant, flexible and light. Its elasticity makes it suitable for achieving higher pressure with small space requirements. A net is also installed around the bag to protect it from animals or possible damages. The exposure to the sun leads to elevated temperature in the bag, that provide a faster and efficient degradation of substrate. Moreover, the bag can be folded, easily transported and removed. The installation of the bag is relatively simple, and can be completed within one day. So far, operating and maintenance costs have been close to zero.


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Material Characteristics Output
PVC 550: UV resistant, flexible and light. Plug flow tubular technology, high degradation rate Gas for cooking activities
High quality welding Removable and foldable Usages of gas for post-harvesting activities such as roasting and drying
Expected life time: 5/10 years Little space required high quality organic fertilizer
low cost technology Easy to install
Easy to install and use Scalable size




Two bags have been already installed and are running efficiently in two farms in Jembrana, West Bali. The farmers are using biogas for cooking and the bag is also feed with the organic waste produced by the local crops (cocoa shell) that cause the spread of pests and bacteria. The next step is to provide a roaster to the farmer and provide the required knowledge to use it, significantly increasing the value of their crops.