Straw pellets
Straw is a common biomass fuel, but in its raw form is difficult to burn, as it is difficult to get the material into the burn chamber quick enough. There are large-scale applications where entire bales are placed in the burn chamber, however these systems are very expensive, and very large.
Converting straw into pellets removes the problem, due to the high density and energy in the pellets; they contain a lot more fuel in a smaller profile. This means small-scale units can take advantage of this widely available fuel. However you must make sure that your pellet burner can handle the high ash and corrosion straw pellets produce.
We were given a few bales of straw from a local farmer, and unlike the wood chippings the moisture of the straw was perfect, creating strong shiny pellets first time. This time we used the 6mm die plate; instead of the 8mm die plate we used for producing the wood pellets.
As straw is more malleable than wood, it is easier to compress into a pellet, so productivity of the pellet mill is higher. We are also very interested in the potential of rapeseed straw. Rapeseed is grown for producing bio-diesel, however the straw is not used and seen as a waste product. This straw will still contain oil, and have a very high heat value. We hope to acquire some in the future to make some pellets.
