About wood pellets, biomass pellets and the stoves that use pellet fuel
24 Jul 2006
Wood pellet fuel is made primarily fom waste sawdust produced during the maufacturing of various wood products, such as flooring and furniture. Biomass pellet fuel is made from corn and other agricultural products. Pellets are burned in specially designed pellet burning stoves.
Pellet fuel is normally sold in 40 pound bags at about $3–$4 each, or about $120–$200 a ton (50 bags at 40 lbs. each = 2000 lbs.) One ton of pellets provides the heat of approximately 1.5 cords of firewood. Most homeowners who use a pellet appliance as a main source of heat will use two to three tons of pellet fuel per year.
Most pellet fuels have a 5%–10% moisture content, while well-seasoned firewood is usually around 20%. Pellets made from agricultural waste contain more ash, but they may produce more heat than pellets made from wood. Corn and other agricultural products are also used to produce biomass pellet fuel.
The Pellet Fuels Institute (PFI) has established National Residential Pellet Fuel Standards, although fuel quality certification is the responsibility of the pellet manufacturer. Under the standards, there are two pellet fuel grades: premium and standard. The only difference between grades is in the inorganic ash content: premium should be less than 1%, and standard less than 3%. Premium is usually made of core wood (not bark). There are five fuel characteristics prescribed for both grades:
- Bulk density per cubic foot not be less than 40 pounds
- The diameter shall be 1/4 to 5/16 inch
- Maximum length shall be 1 and 1/2 inches
- Fines (dust) of not more than 0.5% by weight shall pass through a 1/8 inch screen
- Sodium content shall be less than 300 parts per million (ppm).
You can check pellet fuel quality by inspecting the bag for excessive dirt and dust. Higher quality fuel is most desired because dust, dirt and fines can form clinkers in the stove tha result in performance probems. There should be less than one half of a cup of dust at the bottom of a 40 pound bag. Pellet stoves designed for low-ash tend to operate poorly when used with pellets of a higher ash content.
Although pellet fuel availability is increasing, you should be sure there is a reliable pellet fuel supplier in your area before purchasing a pellet stove. It is also important to know the type of pellet fuel available before you shop for an appliance. Most pellet fuel appliance dealers either maintain a supply of pellets or recommend a supplier. Garden centers and home center stores in some areas also stock pellet fuel on a seasonal basis. Ideally, pellet stove owners will anticipate their seasonal fuel needs and obtain their fuel early. Pellet fuel should be stored indoors, when possible, to keep the bags dry and secure; if moisture enters the bag of fuel, the fuel usually deteriorates (reverting to dust) and becomes unsuitable for use.
This article copyrighted by THE FIREPLACE CHANNEL
INFO CHANNEL HOME
Copyright © 2006 - The Fireplace Channel.com - All Rights Reserved - Site Design: YouComHere.com