Wood chips

Wood chips for energy production are often made of whole logs (firewood), which are not accepted as paper wood or saw logs. There are several specifications of wood chips, mainly depending on the size of the particles. In Europe Wood Chips Standard EN 14961-1 is used. 

Very important is the moisture content of the wood chips. In Northern Europe moisture of the fresh cut wood chips is about 43-45%. After hot summer in September moisture may go down to 35-36%. After the winter, in spring moisture may go up to 48-50%. Wood chips, which have been stored for a long period of time in the open storage and been exposed to rain may have moisture content reaching up to 60%. 

Chipping (cutting the wood in pieces) may be done already at the forest road by mobile chippers, in this case wood chips may be directly transferred from the chipper into the trucks. Mobile chippers in the loading port may also prepare wood chips.

Shipment of wood chips with 3000-5000 mt vessels is rather complicated, as due to their low bulk density chips are taking rather big space on the vessel.  At the same time, the transported weight stays rather small and because of that freight of the vessel turns out to be quite high. It’s better to ship wood chips by big vessels or by barges with high walls. Transportation of very humid wood chips becomes also very expensive, as the end users are paying not for the weight but for the transported energy. It’s recommended to avoid transporting “too much water and too much air”, the moisture content has to be optimal.