If wood pellets are not immediately utilized as fuel they should be packed in order to remain as dry as possible and to avoid influence from water or dampness. To reduce labor requirements, a pellet packing machine may be utilized. There are both automatic and semi-automatic variations on the market.
Once the pellets have been cooled and are of sufficient quality, the pellets are ready to be packaged, stored and sold. How this takes place depends on the target market. Pellets must be protected from moisture and breakage. If moisture comes into contact with the pellets, the pellets will absorb the moisture and expand, making them useless.
The most common way to package pellets are in plastic bags that will hold between 10-20 kilograms. These weights are chosen so the customer can easily lift the bags to load their pellet stove/boiler. In many cases these bags are made from a folded sheet of plastic, which is joined at both ends. These bags can be easily stacked, and are either sold as individual bags or a set on a pallet. Ideally reusable plastic bags should be used with a watertight zip, which are then returned to the pellet manufacturer to prevent waste. Multilayer paper bags are sometimes used as they are easy to recycle. However issues can occur with insufficient moisture protection. Bags are mainly used for residential customers and small-scale pellet burners.
Large sacks or bulk sacks can carry around 1 ton of loose pellets. These are normally utilized at large-scale facilities. The sacks do not provide moisture protection, so are normally loaded into a silo. Pellets sold in large sacks are cheaper than those sold in small bags by weight due to the reduced materials and labor costs.
Some customers have large silos which feed their pellet burner. Here deliveries of pellets can be by a pellet tanker. The tanker will arrive at the property and use a pneumatic system to transfer the pellets into the silo. Silos normally hold enough pellets for several months’ usage.
Exactly how the pellets are stored, packaged and sold is not that important. What is important is that the pellets are protected from moisture. Without moisture protection the pellets will absorb available moisture and expand, loosing mechanical strength and rendering them useless.