“Dragon’s Breath”

From April 10th until April 12th, a new Biomeiler was built at ‘Nature Reserve Dragonmill”. It is a ecological and economical method of utilising wood chips. The method was developed by French forestry officer Jean Pain in the 70s. He had been looking for a way of thinning out the dry mediterranean forests to protect them from forest fires. Being left with large amounts of wood chips, he was then looking for a sustainable and economical way of making use of these chips.

The Biomeiler is a simple device that utilizes the energy which is stored in biomass. Heat, as well as biogas get generated. To build a Biomeiler, about 80 cubic meters of wood chip get piled into a mound of about 3 meters height. Over a period of 18 to 24 months, micro organsims get to work and aerobically ferment the material into highly potent compost. During this process, the temperature reaches and remains at about 70 degrees C. Inside the Biomeiler run tubes which function as heat exchangers. Depending on the intended use, tubes can circulate hot air or hot water. This hot air or water can then be used for hot water, or to heat buildings and greenhouses. It is also possible to produce biogas if a large container with composting material has been put into the Biomeiler. After about 24 months, when the composting process is completed, the compost made from wood can be used for reforestation or for biological agriculture.

The Biomeiler is not for industrial use. Instead, it is used for locally, in a decentralized way. With little technical effort a Biomeiler can be built and used, surely a great advantage compared to modern indunstrial wood-burning plants. Another advantage is, that not all the carbon oxidizes to CO2 (heat generation). Some of the carbon gets stored in the valuable humus in the composed material. This way, the other nutrients which were in the wood chip remain in the the bio mass after composting. It is also possible to extract these nutrients with fire, but the ash usually gets washed out quickly. If the compost is used as mulch, however, new, carbon rich soil is created. Additionally, less CO2 gets released into the atmosphere.

Two weekend workshops, entitled ‘Breath of the Dragon’, attracted 25 people each, aged between 4 and 65. Among the participants were students and teachers from the Montessori School in Dietramszell; a representative of Pfinztal community; a student of soil science from Freiburg; an architect and a member of the city council from Leibzig; as well as studends of the Permaculture Academy. Culinary delights during the second weekend were provided by environment- and peace activist Wam Kat.

The workshops were run by Christian Sven Schembritzki, whose “Naturinsel” has been awarded a UNESCO ‘sustainable education’ award in two consecutive years. During the first weekend, the old Biomeiler was cleared away, and two weeks later, the new Biomeiler 2.0 was erected. “It’s wonderful to experience, during these workshops, the sense of community, how the group dynamics within the group develops and embraces all participants.” says Schembritzki. For two years, the previous Biomeiler was heating a green house and could be used to heat a large bathtub with a 2000 liter capacity. Under the motto ‘Biomeiler 1.0 meets Biomeiler 2.0’, the compost from the former could be distributed in 20 cm thickness across the beds, shrubs and trees of the permaculture garden. According to Jean Pain, this mulch has a very good effect on vitality, yield, as well as quality of the crop, due to the micro organisms and nutrients which are contained in it. Pain also describes how this method eliminated the need to water the plants, even in the dry climate of the Provence.

Two weekends later it was time for ‘Action Biomeiler 2.0’, the construction of the new Biomeiler. The whole process was documented thoroughly by Tom Ruediger with his camera. (soon to be found on our website and on YouTube). A variation to the previous Biomeiler is, that this time the tubes are laid out in spirals, instead of in a cylindrical pattern, with the aim of accessing a larger area inside of the Biomeiler. Additionally, a perforated tube has been included in the Biomeiler to enable the necessary watering process. And finally, a small container has been included to enable research experiments regarding gas production. And another experiment has been included in Biomeiler 2.0: Inside the meiler, a “Terra-Preta” experiment is taking place. Coal particles have been added with the intention of reducing the ‘washing out’ of nutrients. This should also improve air circulation, water absorbtion, and water storage. Additionally, better nutrient and mineral absorbtion by plants can take place, enabling micro organisms a perfect place to live and retreat to.

Various measurements will be taken during the next 2 years, to collect data about the energetic yield and the process of composting. Only very limited information is so far available about this technique. Thus, this experimental installation will primarily be used to collect data and experience regarding mechanisms, structure, and potential uses. For example, a sample of the matured compost has been sent to a laboratory for analysis. In order to have a truly sustainable Biomeiler which can produce high quality compost, it is also relevant to take into account the source of the wood chip. Wood that has been trimmed from the embankments of motor ways and busy roads is not suitable due to its high levels of heavy metals. In our latitudes it is also not necessary to reduce undergrowth, as there is no immediate threat of wild fires. In addition, the habitat for forest animals is already scarce due to the low coverage with forests. However, it would be sensible to make use of garden cut which is usually collected and removed by regional communities. It is also worth noting, that the wood chip should be fresh and not older than 3 weeks.

Those who would like to see the Biomeiler for themselves should consider visiting over Pfingsten (Pentecost). Alternative, you can register for one of the info days by contacting “Naturinsel Drachenmuehle”:

info(ÄTT)drachenmuehle.de

tel: 0-34362-4439-0

www.drachenmuehle.de