Why wood pellets are better than wood chips as fuels?

by Ronny Wei Marketing Specialist

Among the inquiries we received from our clients, many people ask why they need to make wood materials into pellets rather than burning wood chips directly. So today I will tell you the difference between wood chips and wood pellets. Why we should make wood chips into wood pellets?

Wood chips used as fuel

Wood chips are small pieces of wood with the diameter of 5-50mm. It is superior than branch and sawdust as a fuel.

If the wood chips are too large, they would block the feed system of boiler. If the sizes are too small, they would make the burning unstable. Besides, too much wood bark content would influence the burning effect.

So these wood chips need to be pre-treated. If you purchase wood chips from suppliers, they can pre-process the materials as you required. To make them qualified for burning, people use wood crushers or hammer mills to reduce the size, and airflow dryer or rotary dryer to lower the water content.

The advantages of wood chips

Cheaper than wood pellets. wood chip production requires less steps than making pellets.
Various sources and easy to get. Usually people adopt wood chip boiler to take full use of local cheap wood chip fuels.
Good effect on local economy. Forest land owners can manage the wood chip production as they want.

Wood pellet fuel

Wood pellets are form by pellet mills from sawdust and other wood materials. They are solid cylinders, with the diameters of 6-10mm, and length of 10-30mm.

You don’t have to add other additives to make wood pellets, but people add starch sometimes to improve the compactness and stability. By pelletizing process, the wood pellet fuels achieves high density and low water content, and become convenient for transportation and storage.

Advantages of wood pellets

Wood pellets takes less spaces than wood chips. They are more convenient for transportation and storage.
Good fluidity makes them easier for transmission, especially in long pipes.
Owing to low moisture content, wood pellets are less likely to get deformed, and they burn more sufficiently.
Wood pellets can be stored in bags and fed to the pellet burner manually or automatically.

Which you should choose? Wood pellets or wood chips

To choose suitable wood pellet fuel, you need to consider the design of burning system, the specifications of the boiler, and the storage condition. You can make a decision by analyzing the your requirement on storage and transportation.

Some biomass boiler can accept both wood pellets and wood chips. But if you want to change the fuels, you need to adjust the setting of boiler. Some boilers are specially designed for wood pellets. Their narrow feeding device are not available for wood chips.

Before deciding which fuel you are going to use, you should take into account the storage and delivery way. If your storage room is limited, you’d better choose wood pellets.

Delivery capacity is another factor. The larger the delivery capacity, the lower the unit cost of fuel. But if you buy large quantity of wood chips, the volume and freight are much higher than wood pellets.

The delivery of wood chips takes much more efforts for the lack of fluidity. They need lift trailer and containers to support. Wood pellets are usually transported in bulks by trailers or through pipes. This is another superiorities wood pellet fuels have over wood chips.

In conclusion, wood pellets are more superior than wood chips as fuels. Here are the reasons:

Wood pellets takes up less space than wood chips. So they are easier to transport and store, and the delivery cost is lower.
Wood pellets have better fluidity. They are easy to transmit in pipes and automatically fed to the pellet stove.
The pelletizing process reduce the moisture content of wood, so wood pellets have higher combustion rate and less ash residues.
Wood pellets can be applied in more types of pellet heating stoves.
Though wood pellets cost higher than wood chips. But considering the storage and delivery cost and the burning effect, wood pellets are a more economical choice.