How Are Wood Pellets Made?

Made from compacted organic raw materials—including sawdust, bark, wood chips, waste paper and agricultural crop waste—wood pellets are an effective clean energy alternative to fossil fuels and a renewable energy resource.

The raw organic materials are prepped by removing any small particles of metal or stone and are then reduced into small pieces with a hammer mill or shredder. The material is then dried until it is free of most moisture.

Wood stove pellets are then put into a compression device called a pellet mill. Heat and pressure are used to bind the material—whether it’s sawdust, bark, wood chips or some other product—into its pellet shape. Each material is different, as the density of the wood stove pellet affects its combustion efficiency and, therefore, how clean it burns and how effectively it heats your home.

A pile of wood pellets

Wood stove pellets are made from organic raw materials—such as sawdust, bark and waste paper—and are generally packaged in 4-pound bags

Wood stove pellets look like a rabbit food, with a maximum length of one-and-a-half inches and a diameter of one-quarter to five-sixteenths of an inch.

Pellets are usually sold in 40-pound bags costing $3 to $4 each, or anywhere from $120 to $200 per ton. In general, homes that use wood stove pellets as the main source of heat use two to three tons per year. This is often less expensive than electric, propane, natural gas or oil heating appliances.

When considering hard versus soft wood pellets, it’s important to note that most stoves will work with either and how the pellet is made is often more important than the wood used. Softwood pellets generally burn hotter and have less ash versus hardwood pellets. This is unlike regular wood-burning stoves where hardwood burns slower and therefore gives off more heat than softwood.

There are two wood stove pellet fuel grades according to The Pellet Fuels Institute (PFI) standards: standard and premium. What differentiates the grades is the inorganic ash content. Premium pellets produce less than 1% inorganic ash, while standard pellets should produce less than 3%.

Five characteristics apply to both grades. Standard and premium pellets have regulated densities, diameters, lengths, sodium contents, and fines, or dust amounts. How can you check the quality of a wood stove pellet? Inspect the pellet bag for excessive dirt and dust—there should be less than half-a-cup of dust at the bottom of a 40-pound bag. The less of either the better; dirt can build up and make stoves less efficient.

Aside from heating, wood stove pellets are often used as horse bedding and cat litter. The ultra-absorbent, biodegradable pellets often eliminate odors and are easily disposable. Hickory woods are sometimes used to produce pellets for specially created barbecue grills.

Since ash has essential nutrients found in soil, ash from pellets can be used on plants. Be sure to check the bag’s label to see if the pellets are made with—and held together—by lignin, a natural component of wood, while also checking to see if your particular plant species can benefit from wood-based ash.

Call Ricardo Corporation today at (508) 992-0169 to learn more about how you can save on your heating costs.