FUEL QUALITY CHANGES DURING THE STORAGE OF WOOD CHIPS IN LARGE PILES

摘要

Biological degradation processes during storage of fresh wood chips in large piles may cause high drymatter (DM) losses and a decline in fuel quality. To monitor storage effects, two field trials were conducted i. e. oneduring winter and one during summer. For each trial, four piles of wood chips were established using two rawmaterials and two treatments: wood chips from forest residues (FRC) and from energy roundwood (ERC) coveredwith a fleece and uncovered. Additionally, two piles of unchipped raw material were established during each trial tocompare storage effects of chipped and unchipped material. During winter storage, drying of wood chips was low.DM losses amounted up to 1.6 w-% and 0.7 w-% per month for FRC and ERC, respectively. During summer, fuelquality of wood chips in piles improved due to large drying effects. However, DM losses of ERC were twice as highcompared to winter. Storage of unchipped material did not improve drying but led to lower DM decompositioncompared to storage in wood chip piles. Thereby, the loss of bark material and needles increased total DM losses inunchipped storage piles but positively affected fuel quality parameters.