The typical households in the research project comprise five people, a cow and a banana plantation that is approx. 1.2 ha. There is no electricity available wherein the people rely on wood as a fuel for cooking and heating. The people must walk many miles to collect the fuel. The smoke pollution caused by cooking on an open fire endangers the health of the population. Small biogas plants might be able to improve this situation, in turn enabling the people to produce the required fuel themselves. Students of the "Raw Materials and Bioenergy" course at the University of Hohenheim are investigating the use of small biogas plants for the production of fuel in Tanzania. This is a project that was initiated by the association "Engineers Without Borders" (EWB), which is working on the further optimisation of these biogas plants in Berlin. The BayWa Foundation is supporting the project with a sum of 5,000 euro.

The students and their supervisors will begin to set up their pilot plant at the beginning of August 2009. They will imitate the Tanzanian climate by placing the pilot biogas plant in a greenhouse on the University campus. They will thoroughly test the pilot plant, before a prototype, which is being developed by the Hohenheim students and professors in co-operation with EWB, will be set up in Tanzania, most likely in spring 2010. EWB is working together with its Tanzanian partner "MAVUNO Project", which is organising the maintenance of the future biogas plants in Tanzania and training the population on how to set up and maintain the systems.

Requirements in Tanzania determine the speed of development

The aim of the project is to keep the biogas plants fully operational in Tanzania over a period of many years. For this aim to be achieved there are a number of prerequisites that must be satisfied: The Hohenheim scientists need to develop a new type of biogas plant and optimise process control, which in turn is associated with new requirements in the prototype; the prototype needs to work effectively with the wood that is available in the Kagera region; the technical expertise required to operate the plants must be effectively passed on to the local population; maintenance work and costs need to be kept at a minimum, and the material costs required for the plant must not exceed 400 US dollars.

Biogas facilities - simple and effective

The functional principle of the small biogas plant is simple: Banana leaves, cattle dung and kitchen waste will be fermented in a hermetically sealed container. The efficiency of the microbial degradation process depends on the temperature - the higher the temperature the faster the biological materials are degraded. The bacteria contained in the fermenter feed on the organic material and produce biogas - mainly methane and carbon dioxide, which can then be stored, produced and used around the clock.

The gas, the production of which is cheap, clean and technically simple, can be used to fire gas cookers and light gas lamps. In addition, the remainder of the fermented materials is an excellent fertiliser that can be used on the people's own plantations.

Biogas plants make life easier

Biogas plants have numerous advantages for the life of the Tanzanian population. The biogas plant is an easy way to produce energy for the entire household without entailing high costs. Biogas alternatives - wood or charcoal - can only be obtained with difficulty, or if purchased, are very expensive. The families have to traverse increasing distances when collecting wood and the purchase of fuel represents a high financial burden for the entire community. The biogas plant uses materials that would otherwise simply be thrown away. In addition, burning biogas is far cleaner than wood and, therefore, helps reduce indoor smoke pollution from cooking on an open fire.

The study project of the University of Hohenheim

The project of the Hohenheim researchers entitled "Biogas support for Tanzania" (BioGaST) is not a normal research project; it is rather a study project. 14 fourth-semester students of the "Raw Materials and Bioenergy" bachelor's degree course are a part of the project. They are working closely together with lecturers and professors of the agricultural science and agricultural technology departments on the optimisation of the biogas plants. The students will also be given marks, which will be a part of their bachelor's degree, but they are also very excited about the possibility of being able to carry out independent research as well as enjoy the application-oriented training.