Raw material production
Solid wood modelling
Solid wood is one of the most widely used and complicated materials to model in industrial production.
To ensure robust climate footprint calculations, the raw material stage is modelled in three distinct steps:
Forestry
Sawmilling
Kiln drying
Each of these three steps will vary depending on :
- Species variability
- Moisture-dependent energy demand
- Thickness-dependant energy demand
- Geographic variation in forestry and transport
By modelling these parameters explicitly, Målbar avoids oversimplified raw material averages.
Each stage is based on recognised LCA datasets and energy consumption needs documented in literature.
Raw material emissions for dried wood in Målbar:
- Are species-specific
- Reflect realistic drying energy demand
- Include process-level electricity and waste
- Use recognised Ecoinvent datasets
- Apply geographically specific energy mixes and transport distances
Forestry emissions
Forestry emissions are modelled using Ecoinvent datasets specific to wood species and forest management type.
Example dataset:
Ecoinvent 3.11
“hardwood forestry, oak, sustainable forest management, sawlog and veneer log, hardwood, measured as solid wood under bark”
Data is converted from m³ to kg using species-specific dry density values to ensure mass-based consistency in the life cycle model.
Forestry modelling reflects:
- Species-specific characteristics
- Sustainable forest management practices
- Geographically specific electricity mixes
- Transport of wood logs
Sawmilling
Sawmilling energy use and material losses are modelled using:
Ecoinvent 3.11
“sawing, hardwood, sawnwood, hardwood, raw”
The dataset includes:
Electricity consumption
Process-related waste
Conversion losses
Allocation to co-products – sawdust, bark, slabs and sidings
Impacts are converted to kg dry wood to ensure consistency
with downstream kiln drying modelling.
Kiln drying
(to 10% moisture content)
Dried solid wood is typically kiln dried to approximately 10% moisture content (MC).
Drying energy is adjusted based on:
- Wood species
- Board thickness
- Entry moisture and final moisture content
To isolate oak-specific energy use from mixed hardwood datasets (oak, beech, birch), drying time assumptions – and hereby energy consumption – are based on:
Life Cycle Assessment of Rough-sawn Kiln-dried Hardwood Lumber (AHEC, 2012)
Drying factors are modelled as functions of:
- Thickness (mm)
- Entry and exit moisture content (%MC)
This avoids applying generic drying averages and improves species-level accuracy.
The required electricity and heat are derived from:
Ecoinvent dataset
“board, hardwood, raw, kiln drying to u=10%”
- Residual electricity mixes by country
- Biomass-based heat where applicable
- Conservative assumptions where primary data is unavailable
Energy modelling principles
Forestry and electricity mixes are geographically specific.
Heat in kiln drying is typically generated from wood residues (biogenic sources), although fossil heat may be used in some installations.
Energy modelling therefore reflects:
- Residual electricity mixes by country
- Biomass-based heat where applicable
- Conservative assumptions where primary data is unavailable