The company Raiffeisen Agil & the fair „Heizen mit Holz“: new technologies presented in Germany
As completion to the national workshop in Soltau (Germany), described in the third article of this newsletter, the company Raiffeisen Agil in Leese and the fair “Heizen mit Holz” in Fuhrberg were visited on the 22nd of October 2016. In total 28 participants from Germany, Spain, Italy, Czech Republic, Belgium and the Netherlands joined the field trip.
The cooperative Raiffeisen Agil in Leese was one of the pioneers in the field of bioenergy and generates today enough energy with wood chips and biogas to cover the requirements of 15 companies and 120 staff members on-site. Particularly in the case of supply with renewable raw materials, such as wood, the Raiffeisen Agil is one of the largest suppliers in Northern Germany.
Led by the manager Mrs. Ronnenberg and the technical head Mr. Bartels the main features on the 63 ha large area (former military base) were visited. First, the wood chips drying system was presented. Powered by electricity and using the waste heat of the nearby biogas plant, the drying container is able to process 3 – 5 m3 of wood chips per hour and produces an energy carrier fulfilling high quality standards (G30/W20, 20 % moisture). In total, the company sells 8000 t of these wood chips per year. Additionally, by removing wood contained in compost material (not composted yet) and shredding it, woody biomass of lower quality is gained. Without further treatment, this is sold to big power plants that are able to burn it in their boilers.
Waste wood is the third type of woody feedstock managed by the company that is processed to an energy carrier. As defined by the German law, the waste wood is sorted on-site into four categories according to the degree of contamination, which ranges from non-lacquered EU pellets up to train track sleepers. After removing any kind of metal, mostly nails, it is allowed to use the material from the first category to produce an energy carrier. The Raiffeisen Agil sells yearly about 8000 t of this type of recycled energy wood.
In the second part of the field trip the fair “Heizen mit Holz” in Fuhrberg was visited. This event takes place every two years and about 100 different companies present the newest technologies for the use of renewable energy. During the tour with organiser Carsten Brüggemann equipment for the preparation of fire wood was presented and different machines to chip wood could be inspected in action. Further, a wide range of firing possibilities was shown starting from fireplaces over log-burning boilers up to automatic firings for wood pellets and chips.
Leaves, needles, bark, attached humus and sand particles are dust generating elements in wood chips which can be found mainly in the fine share of the fuel and can lead during combustion to high dust emissions. This is especially the case for material from landscape conservation and maintenance work. With stationary or mobile sieving systems these fine fractions can be significantly reduces. Thus, besides a drying system in a container, a star-roll separator and a drum sieve, to sieve wood chips in operation, were presented in action.
Authors: Aline Clalüna, Carsten Brüggemann