Our biomass chip is Woodsure Plus accredited, for an independent guarantee of quality, sustainability and traceability. We take samples of every batch to allow for precise charging and to allow quality control.
Main characteristics
We carefully source, produce, and deliver our woodchip to ensure it consistently complies with the specific requirements of our clients’ installation. We supply woodchip to the following specifications:
| Moisture content | As per customer requirements (expressed as per Onorm or BS standard) We can generally supply in the 20-50% range |
| Calorific value | Typically above 3,000 kWh/t, depending on moisture content |
| Size classification | G30 (Onorm) P16B (BS 14961-4:2011) We can produce other sizes (incl. G50) on order, out of the accreditation scope. |
| Contaminants | Contamination free |
Due to our high quality standards, we have also a B grade chip, which is available at discounted prices.
Importance of constant quality
Alongside competent design and appropriate maintenance, the reliable supply of consistently high grade woodchip, meeting the appropriate specifications for the installation, is one of the most critical factors in ensuring efficient, clean, and fault-free operations of a biomass boiler.
Moisture content is one of the key determining factors for woodchip quality as it affects its calorific value and durability (see table below). The acceptable thresholds vary with the make, type and size of the boiler and its feeding system.
| Too wet | Too dry | |||
|---|---|---|---|---|
| Risks associated with inappropriate moisture content | ||||
| Storage | Above 35-40%, composting can happen at the core of the heap, leading to reduction of calorific value and risk of fire due to high temperature.Spores can germinate, leading to fungal growth. |
Risk of fine dust. |
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| Transfer | Woodchip may be too sticky for the boiler feeding system. | Risk of fine dust. | ||
| Combustion | MC above the threshold will lead to inefficient combustion, excessive smoke, and may cause the boiler to shut down. | MC below the specification window will burn too fast and may cause heat damage to parts of the boiler. | ||
Calorific value(CV) is the amount of energy (heat) per unit of weight or volume. It is inversely proportional to the moisture content.
Size classification, also called dimensions, defines the chip particle size distribution and is measured by passing the sample through a range of sieve sizes. The BS/EN standard requires that 80% of the particles are retained by a given sieve size. This ensures a limited amount of undersized and oversized particles, contributing to good working order of the boiler and feed system.
Contamination can damage the transfer system and boiler. Our woodchip is free from physical contaminants (e.g. stone, metal, rubber, plastic, un-chipped pieces of wood), and chemical contaminants (e.g. any form of treated or painted wood, MDF, heavy metal compounds, halogenated organic compounds, creosote).
You can find out more about biomass chip specs and why they matter here.