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Pellets and Fuel 101
What are pellets made of?
All pellets are biomass materials, that is, products of commonly grown plants and trees. The most common residential pellets are made from sawdust and ground wood chips, which are waste materials from trees used to make furniture, lumber, and other products. Resins and binders (lignin) occurring naturally in the sawdust hold wood pellets together, so they usually contain no additives. Nut hulls and other materials are pelletized in some areas, and unprocessed shelled corn and fruit pits can be burned in a few pellet stove designs. Your fuel of choice and its price may depend on the waste biomass most available to pellet mills in your
region. In turn, your choice of appliance design depends on the fuel available.
Where do pellets come from?
Pellet mills across the country receive, sort, grind, dry, compress, and bag wood and other biomass waste products into a conveniently handled fuel. Today, over sixty pellet mills across North America produce in excess of 680,000 tons of fuel per year, a figure that has more than doubled in the last five years. Pellets are available for purchase at stove dealers, nurseries, building supply stores, feed and garden supply stores, and some discount merchandisers. Pellets are usually packaged in forty pound bags and sold by the bag or by the ton (fifty bags on a shipping pallet). Some mills offer twenty pound bags for easier handling.
What choices do you have?
Pellet fuel comes in two different grades. The premium grade makes up about 95% of the fuel produced, where as standard grade make up the balance. All pellets are required to meet certain size and uniformity to insure a uniform feed rate and reduce jamming or bridging to occur. The optimum size is less then 1.5 inches in length and preferably even less then 1 inch to prevent bridging in the hopper where the pellets drop onto the auger. The premium grade will have less them 1% ash content when the pellets are burned. High ash content is normally caused by an excess amount of bark mixed into the pellet. The lighter in color the pellets are will indicate the amount of bark, e.g. very light means no bark, very dark means a lot of bark. Premium grade pellets can be made from both hard woods and soft woods. The wood that is used is usually determined by the local source of wood that the pellet mill has available to them.
It usually is a good idea to test burn several brands of pellets before making your finale choice to determine what you what to stock up on to keep you warm for the winter. Different brand usually will have different prices. Don't rule out the less expensive brands without testing them 1st. Do a visual on the pellets when you empty the bag full of pellet into your stove hopper, make sure there is not a lot of loose sawdust in the bottom of the bag although some sawdust will be normal. Some pellet stoves do not feed this loose fines very well, nor do these fines produce a lot of heat value as they usually just turns into fly ash, meaning more intensive cleaning to keep you pellet stove air flows from being restricted. Some consumers actually screen the fines out of the pellet to insure correct pellet flow from the auger. Do make sure that the pellet manufacture is supplying premium grade of pellets as this should be listed on the bag.
Can my wood pellet stove burn corn kernels?. The answer is yes maybe, but in a mixed corn/pellet mixture only. Corn burns hotter and could shut your stove down due to much heat, so be careful not to be too aggressive with a high heat setting. Corn has a lot of what are called clinkers which are hard substances that builds up in the burn pot and have to be removed more often than the buildup from pellets. If these clinkers are not removed, air flows are disrupted and the stove does not function correctly. Most pellet stove manufactures do not recommend corn to be burned in their appliances as they know of the potential problem the consumer may have. If you do decide to try to burn corn, begin with a limited quantity mix thoroughly with your pellets. The rule of thumb is not to exceed 30% to 50% corn to pellet ratio.
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