The most significant producers of wood pellets can be considered as countries such as usa (2000 tons per year), Sweden (700 tonnes), Denmark (600 tons), Austria (120 tonnes), Germany (about 100 thousand tons), Canada (100 thousand tons), Finland (96 tonnes), Britain (6 tons), Japan (2.3 tons). Britain plans by 2010 to bring the consumption of wood pellets to 600 000 tons. The growth of consumer alternative fuel from various countries is increasing annually. Credit: Ripple-2011. Production of pellets in the near future will make a significant contribution to the global strategy for renewable energy. For example, Sweden in 2002, 20% of all their needs (this about 100 TW) covered by the use of biofuels.
standards pellet Currently there is no common European standard for pellets, so a few names of some existing national Standards: Austria – onorm M 7135 Austrian Association pellets (briquettes and pellets) England – The British BioGen Code of Practice for biofuel (pellets), Germany – din 51731 (briquettes and pellets) usa – Standard Regulations & Standards for Pellets in the US: The pfi (pellet) Switzerland – sn 166000 (briquettes and pellets) Sweden – ss 187 120 (pellets); Pellets according to Swedish standard (SS 187120) – are pressed cylinders with a maximum diameter of 25 mm. Under this standard, the pellets are divided into three groups, starting with the I-th (pellets of the highest quality) to the III-s (industrial). Austrian standard onorm M 7135 classifies pellets according to the type of feedstock: the pellets from wood and pellet from the crust. Dimensions in both cases, the following: the diameter of 4-20 mm and a length of 100 mm. According to German standard din 51731 pellets should have a diameter in the range of 4-10 mm and a length of not more than 50 mm. It should be mentioned that all standards govern a parameter called ash, which has a major influence in the presence of the raw material of bark, branches and other impurities. production technologies Since our inception in 1947, the technology of production of pellets a little what has changed. The very process of granulation – occurs in special annular dies (molds) rotating rotary rollers are pressed into the numerous holes – die mold activated by steam chopped wood raw material, then, cut on the outside of the stamp with a special knife pellets must be cooled and separated from small particles. Considering the entire production process, it can be divided into several stages: – Crushing (primary, coarse in chippers) – Drying – Milling (final refinement – refining) – Pressing (granulation – ) – Cooling (Air conditioning) – Separation (separation of non-conforming fraction of the full-size pellets).
