Make Wood Pellets And Other Fuel Pellets

Wood pellet production is a rapidly growing industry, on both a small and large scale. The two main uses for wood pellet fuel are the home heating market, and providing fuel for power stations. Many coal power stations today use wood pellet fuel in co-combustion with coal to reduce the carbon emissions of the plant. This is a very affordable method for the power stations to meet carbon targets without having to invest in new equipment or processes. Other than the home heating market and power stations, wood pellets are also used for pellet grills and for animal bedding such as horses.

To make wood pellets, a series of processes and material requirements are needed. One of the first key criteria to producing a quality wood pellet is only a consistent raw material can produce quality consistent wood pellets. The consistent qualities the raw material requires is a low moisture content and small particle size. The raw material also requires a sufficient proportion of natural lignin found in all biomass. However certain biomass has more natural lignin than others. Wood generally has enough natural lignin for wood pellet production, however other biomass such as straws and grasses may require an additional binder to hold the pellets together. Purpose made binders are commonly made from modified corn starch, the binder can also help with lubrication.

The Basics of Wood Pellet Manufacturing

The first process to make wood pellets is size reduction. The wood raw material maybe in the form of logs, wood chip or even sawdust. To reduce the wood to a small uniform size a combination of a wood chipper and then hammer mill solution will likely be required. Once the wood has been reduced to 6mm particles or below, it is then ready for drying.

Drying involves either a pipe flash dryer or a rotary dryer. The general rule of thumb is that flash dryers are used form small scale production and rotary dryers are used for large scale production. Flash dryers are cheaper, however are basic and are not suitable for wood with a high moisture content such as virgin wood. Rotary dryers are more expensive however they also have more control and are suitable for virgin wood.

Wood Pellet Mills and Pellet Compression

After size reduction and drying the particles are then ready for pellet compression. As with drying, there are pellet compression solutions which are more suitable for small scale and large scale production. For small scale production, even home use a flat die pellet mill is more practical and affordable. The basic design of the flat die pellet mill means it is cheaper to manufacturer and also maintain as the consumables are cheaper to produce. For large scale production ring die pellet mills are commonly used as they use less electricity.

When the sawdust enters the pellet mill, compression through the die generates both heat through resistance and pressure. A certain level of resistance is required to help the pellet form, however to much resistance will cause the wood to become blocked in the die. When the pellets leave the die, they are very hot and before they can be stored they need to be cooled to ambient air temperature. Also before packaging the pellets must be screened to removed fines from production.

PelHeat Wood Pellet Production Guide

At PelHeat we have many years of experience in pellet production, and we provide a pellet production consultation service. The PelHeat guide download will show you how to make wood and other fuel pellets.

 The Wood Pellet Production Guide © PelHeat Ltd - Make Wood Pellets