Nowadays there is a green raw material being widely used in many countries around the world, especially the European and American countries, known as wood pellets. Environmental pollution is getting worse, so a new clean energy such as wood pellets will be an alternative to the heating fuels used in family or factories.
Also, you can also use wood pellets for cooking stoves to help raise the temperature up quickly and produce more heat. Although you can easily buy a large amount of this material from the factory and burn them by pellets stoves or pellet fireplace during the cold season, why spending money when you can manually make them by using raw materials that are always available in your home?
All organic waste that every household litters a day like sawdust, leaves, fruit shells, grass, food waste and garbage can be put into a mill and compressed into dense pellets. In addition, you can mix yard waste with wheat, grain, straw, corn, twigs, branches, shrubbery, paper, cardboard … with the wood to make wood pellet. This solution does not only save money but also help you save even more energy. Here are some steps that will help you learn how to make wood pellets with sawdust.
The first thing you need to do before learning how to make wood pellets is to choose the most suitable pellet mill, as currently on the market there are many kinds of machines with different quality and capacity. Ideally, you should choose a pellet mill with small size called flat die pellet mill.
This machine is very popular in its simple structure, which consists of a flat die and a roller goes across it. Raw materials go into the mill will be pressed between the compression roller and die, and then through the holes of the die to be formed into cylindrical pellets.
Choosing material is simply because they are available in almost all around us, but how to collect them is another matter. You will need a car to transport the sawdust, branches, leaves, etc. to home. Consider transmission distances because if it costs a lot when transporting raw materials for a long way, then directly purchasing wood pellet from the wholesale market may save even more money and time.
Moisture content of raw materials
The moisture content of wood pellets is an important factor affecting the compression process. At 10% to 20% of moisture, wood pellets will have good quality and the best shape. Lower humidity will make the pellet dry and brittle therefore you need to spray up a little water before conducting the compression. In contrast, if the moisture content is too high, it will not be able to create
In contrast, if the moisture content is too high, it will not be able to create wood pellet. Therefore, the raw materials need to be dried naturally under the sun for a few days or by an industrial heating oven if necessary.
Sawdust with high moisture should be stored separately from those with low moisture content. In general, to make a ton of pellet needs about 7 m3 of sawdust with around 50% humidity.
Before putting the raw material to the mill, you need to conduct screening them to remove impurities. For examples stones, plastic by stone trap, and metals by magnets. Thus, they will not affect the quality of the pellet or damage the mill.
Pour all material into a batch mixer to ensure all of them will have the same density, moisture level, and length (less than 1 inch).
How to make wood pellets
You cannot just gather all raw materials and feed them to the pellet mill. The first thing you need to do is to break or shred them into small sizes that are less than 1 inch. If necessary, use a hammer mill to reduce their size even smaller, as long as you do not turn them into sawdust.
Start the pellet mill and wait for a while to heat the flat die. When the temperature rises, lignin will easily break out fibers and helps link sawdust into pellets.
Shovel a small amount of sawdust into the hopper. Put a box under the mill’s chute to catch the wood pellet fall after being compressed.
Some pieces will fall apart or break during the pressing process. Put all wood pellets into a large sieve and shake it to separate the improperly compressed ones.
Take some time to let the new wood pellet cool off before burning them in pellet stoves. The wood pellet falls from the mill will be very hot and moist. Thus, you need to spread them out and dry them naturally. Store the unused in a sealed plastic bag and put them in a high and dry place away from water.
The last step is to check the quality of wood pellets come out of the pellet mill. After being compressed by the mill, solid and bright pellets are qualified. If they are soft and pulpy, take the time to dry them out. Then, put them back in the mill to compress again. If they are easily crumbled, unfortunately, you have to throw all away and start over with a little spray of water onto the raw material.
Maintaining the pellet mill
After finishing the work and get the perfect wood pellets for heating, do not forget to clean the pellet mill carefully, especially the die and the roller. Despite having done the screening process, some impurities may still be leftover in the sawdust and stuck in the machine. This causes damage if you do not pay attention to the cleaning. Also, remember to maintain those parts that bear high friction and heat.