In today’s article we will see how to make pellets at home and then industrialize them. For those who do not know, pellets are small pressed sawdust conglomerates, which are used for combustion in boilers and cookers.
I must clarify that manufacturing them is not at all easy, since their quality will depend on the raw material used and from it you can have one type of product or another. The pellets have to be three centimetres in size and they will have to be pressed as much as possible to have better energy efficiency.
At the end of the manufacturing process, the quality must be tested to prevent damage to boilers and cookers.
Manufacturing Wood Pellets: Types and Materials
As mentioned above, pellets can be made from different materials, so we may have different qualities of pellets. If we wish to obtain a product for home use, the raw material to be used can be branches, straw or tree bark, which are the most chosen when producing pellets. You can also choose to use a single material for its manufacture, but its energy efficiency could vary greatly.
However, the best quality and most combustible pellets are those made from Scots pine, but their cost may be a little higher. As I said, in order to produce pellets industrially, a balance must be found between cost and quality. The best option is to use as raw material olive stone or pine wood, which are the most efficient and achieve an excellent combustion.
How are pellets made? Step by step
You are probably wondering how to manufacture wood pellets, because before explaining the procedure, I must clarify that to be able to manufacture it, you need a special machine, which crushes and compresses the pellets.
1st Step: Reducing the size of the raw material
The first step is to cut the raw material, whether branches or wood, until the size is ideal for pressing. The raw material should be the same size as the sawdust.
2nd Step: Remove the humidity from the wood
In case you didn’t know, the success of pellet combustion is due to the fact that they contain no moisture at all, so before compressing, the moisture must be reduced to less than 15%. It is advisable to use a temperature lower than 25 degrees to dry, and thus avoid the matter to be burned.
3rd Step: Mixing
As a third step before manufacturing the pellets, the different materials must be mixed with water and then passed to the compressor. The water serves as a glue for the mixture, causing the raw materials to stick together and compact successfully.
4th Step: Pressing the pellets
Once the materials have been mixed, it is time to press, which is done with a high pressure machine and a special temperature. Something to keep in mind is that to achieve high quality pellets, they must be pressed as much as possible.
5th Step: Bagging
The last step is to bag the pellets in sealed bags or packages to prevent moisture from entering the bags.
Quality control of the pellets
However, once we have manufactured the pellets, we must check that they are well made, and there is a technique that never fails to do this. Which is to place a pellet in a glass of water, if this sinks it is because it is well made and its combustion will be of quality. If the pellet sinks, it is because it is not pressed enough, and this can cause moisture to enter it. Also, when a pellet is badly made, it tends to leave residues everywhere and also breaks easily.
As I said at the beginning of the article, for a pellet to be of high quality it must have a humidity of less than 15%, since with that percentage its combustion will be much higher and it will avoid damaging the boilers or cookers. Also to be sure, you can consult the quality standards established for Europe or in Spain.
To be able to corroborate the quality of the pellets it is ideal to have a biomass cooker and thus ensure that it meets the standards.