How long do wood pellets last? How to store wood pellets?

When families or companies produce or purchase wood pellets, the total amount is usually much more than they need. They store the wood pellets for future use or for sale. So, the questions are: how to store wood pellets? can wood pellets be stored outdoors? how to prolong the storage life of wood pellets?

How long do wood pellets last?

Wood pellets are formed by the high pressure of pellet machine. In the chamber of pellet mill, the high temperature cause chemical changes of the lignin in biomass materials. Biomass pellets contains 75-85% carbon, 3-6% ash content, and 1-3% moisture. They features small volume, low density, high purity, high calorific value, convenience for store and transport.

Usually, wood pellets are packaged in plastic bags or woven bags. They cannot separated wood pellets with air and moisture completely. The storage life of biomass pellets depends on the humidity of the surroundings. When the moisture content in wood pellets reaches a certain level, they would get loose and unable to use.

If the environment humidity is lower than 10%, the wood pellets can be preserved for 6 months. If it is higher than 10%, the preservation time is 1-3 months. Usually, wood pellets are produced or purchased according to the use demand. Storage for one-month use is enough, so it is not common to exceed the preservation time.

Besides, you can make your own wood pellets with a wood pellet machine. It doesn’t take you much money or power. And the raw materials are easy to get. If you need wood pellets for long-term use, a pellet machine is more economical. And you can control the production according to your needs, without worries about the storage.

How to store wood pellets?

As said above, the environment has influence on the storage life of biomass pellets. If stored improperly, they would easily get damp and cracked, and unqualified for burning. The key to preserve wood pellets is to keep it from moisture and fire.

Damp proof

Biomass pellets are easy to get loose and incombustible when it contact with water. Therefore, the moisture content in the air are adverse to the wood pellets, especially in rainy seasons. So we should store the wood pellets in damp-proof packages. By this mean we can preserve the pellets in various conditions.

If you decide to save money and adopt non-water-tight package, you’d better keep them indoors, or you would have to move them when it rains. Make sure the room is dry and well-ventilated. Because the biomass pellets would get damp and loose when the moisture content is about 10%. Raise your wood pellets off the ground by putting the bags on a pallet or cardboard slip sheet.

Outdoor storage

For people without enough room to store wood pellets, a shed or shelter in high and dry place is a compromise choice. Inspect and mend any rips or holes in the bags with water-proof tapes. Cover the pellet bags with an additional, securely fastened tarp, so as to protect them from water, birds and punctures.

Fire prevention

Biomass pellets are flammable products. Any open fires have the chance to cause fire disaster. When you have purchased or produced wood pellets, don’t pile them up around the stove or boiler. Someone should be put in charge of the inspection of safety hazard.

In terms of home-use pellets, parents should look after their children in case they set fire to the pellets.

Special requirement

In open air condition, there would be mould and spores growing in the corn stalk pellets when the temperature is 25%, and relative humidity is 70%. So the relative humidity for corn stalk pellets storage should be under 60%. It is necessary to install ventilation and dehumidifying equipment in high-humidity areas.

Under high temperature(43℃) and high-humidity(90%) condition, there would be crackers, molds on the surface of wood pellets. This is not a favorable condition for pellets storage.