Drying woodchips
Time : 2019-01-07 Writer : ddjx
Energy from biomass
Producing energy from biomass has significant environmental and economic advantages.
It is a carbon neutral process as the CO₂ released when energy is generated from biomass is balanced by that absorbed during the fuel’s production. Compare this to the massive energy loss from grid electric supply and the use of fossil fuels for heating, biomass is a logical, long term solution.
Reasons for drying woodchip
The usable calorific value of woodchips depends much more on the woodchip’s moisture content than on the species of wood. Fresh wood chips with a water content of 55% provide roughly 2000 kWh in energy per ton.
By drying woodchips to 20% moisture content, the calorific value is doubled to around 4000 kWh per ton. In a burning process of 1 ton of dried woodchips, approximately 400 L of heating oil can be substituted.
For woodchip boilers, dry woodchips equate to higher efficiency, clean and more consistent combustion that in turn ensures simple operation and an extended lifetime of the heating system.
In addition, only woodchips below 30% moisture content are suitable for storage. Woodchips above the 30% threshold are liable to microbial decomposition.
Advantages of drying woodchip
•Making good use of spare residual heat throughout the year
•Efficient biofuel production, handling, storage and transport;
•Increased income from wood fuel sales;
•Spare waste wood utilisation possibilities (tree trimmings & sawmill residue);
•Ability to store woodchips (woodchips with moisture content >30% are subject to microbial decomposition);