As stated in earlier posts, the key issue that any interested small-scale pellet producer needs to address is the moisture content of their raw material. Any material to make a pellet to burn will be in the range of 10-20%. The exact moisture content is specific to that material, for example wood is generally 10-15%, but straw may require a little more than this to work well. There are purpose made material driers, but they tend to be very large and very expensive, there are more energy efficient and environmentally friendly solutions like solar driers, and I will address these in later posts.
There is another solution!
The basic problem is you have a raw material that is too moist, what you need is another raw material that is dry, to mix the two together to create a raw material of the correct moisture content. Now any biomass material can be used, but there is one material that is in vast quantities and is not fully utilized.
Cardboard
Or more specifically plain packaging cardboard, which has very little contaminates. With the vast quantities of cardboard produced, larger amounts still end up in landfill. Also cardboard cannot be constantly recycled, to make more cardboard. Once it has been recycled 3-4 times the fibres are so broken that they cannot be formed again to create a strong box. So what we are left with are vast quantities of a biomass waste material that has very little use and value, and more importantly a dry material.
At PelHeat we have made 100% cardboard pellets (see above), and they are very strong pellets, their key disadvantage is they have very high ash content, so require a lot more maintenance. Mixing cardboard with another raw material through, perhaps virgin wood could reduce the volume of virgin wood required to produce your required pellets, and you would not need to dry the virgin wood, by mixing the correct proportions of each material to get the right moisture content.
Summary
So mixing cardboard with another material could potentially solve the moisture issue and extend your raw material. You must however check waste handling and burning regulations in your area with regard to cardboard.
Thank you for your interest
