Wood Chips for sale
Advantages over logs
Also, the relatively small surface area to volume ratiomakes efficient combustion or gasification difficult to achieve.
Wood chips can form a much more uniform fuel that can flow and can be fed to a boiler, gasifier or other conversion system as a steady flow using an auger feed or a conveyor.
To produce chips suitable for most boilers requires a specialist chipper designed for woodfuel use to produce chips of even size that will flow well and ensure there are no long slivers that can cause jams or bridging. A general purpose chipper is not suitable.
Using in energy applications
Wood chips may have a bulk energy density of about 40-50% of that of the solid wood.
Physical parameters, such as maximum size and absence of slivers or fines (sawdust), and maximum moisture content are important to allow reliable operation and prevent feed blockages. Also levels of contaminants and ash content will have an impact on emissions and maintenance schedules.
The British standards for solid biomass, including wood chips, allowall of these parameters, and acceptable ranges,to be defined.
The characteristics of wood chips will depend both on the chipper and the material from which they are made.They can be divided into groups:
- Forest chips – including:
- Log chips- from delimbed stem wood
- Whole tree chips- from all the above-ground biomass of a tree
- Logging residue chips- from branches, brash, etc
- Stump chips- from stumps
- Wood residue chips- from untreated wood residues, recycled wood and off-cuts
- Sawing residue chips- from sawmill residues
- Short rotation coppice/short rotation forestry chips- from the respective energy crops.
Storing wood chips
Wood chips should be stored under cover to prevent wetting, however good airflow is necessary to disperse water vapour and minimize the chance of composting and mould formation.