Every wood pellet spec sheet lists a similar set of numbers – moisture content, ash content, calorific value, bulk density, mechanical durability. For a buyer new to sourcing biomass fuel, it’s easy to skim past these as boilerplate. In practice, each one affects how the pellet performs in a boiler, and how much a buyer should trust a given quotation. Here’s what each measurement actually means.
Moisture content measures how much water remains in the pellet after processing, typically expressed as a percentage of total weight. Lower moisture generally means more efficient combustion – energy isn’t wasted evaporating water before the wood itself burns – and better storage stability, since higher-moisture pellets are more prone to mold and structural breakdown over time. Industrial-grade pellets typically target moisture content in the low single digits to around 10%, though exact thresholds vary by standard and application.
Calorific value measures how much energy is released when the pellet is burned, usually expressed in kcal/kg or MJ/kg. This is the number that most directly determines fuel efficiency for a power plant – higher calorific value means more energy generated per tonne shipped, which matters both for combustion output and for the economics of transporting biomass fuel over long distances.
Ash content is the non-combustible mineral residue left after the pellet burns. Lower ash content is generally preferred, since ash buildup requires more frequent boiler cleaning and disposal, and can affect combustion efficiency over time. Ash content is also one of the parameters most directly affected by raw material quality – bark, dirt, or contamination in the wood feedstock all increase ash content in the finished pellet.
Bulk density measures how much a given volume of pellets weighs, and matters primarily for shipping and storage logistics – higher bulk density means more fuel by weight fits into the same container or storage silo, directly affecting shipping economics.
Durability measures how well pellets hold together during handling, transport, and storage – resisting breakage into fine dust. Low durability creates two problems for a buyer: fine dust represents lost usable fuel, and dust accumulation during storage or handling can create combustion and dust-explosion safety risks in industrial settings.
Pellet diameter (commonly 6mm or 8mm) and length need to match the specifications of the buyer’s combustion equipment – feeding systems and burners are often calibrated for a specific pellet size range, making this a compatibility requirement as much as a quality one.
Any supplier can list target numbers on a quotation. The more useful question for a buyer is whether those numbers are backed by consistent testing and, ideally, third-party certification – such as compliance with ISO 17225 grading or ENplus certification – rather than a one-time sample sent for initial evaluation.
The ranges above reflect typical industrial-grade wood pellet parameters across the market, not a substitute for a formal specification sheet. Because combustion equipment and contractual requirements vary from buyer to buyer, the most useful next step is a direct conversation about your specific equipment tolerances and application.
Phu Tai provides detailed, current specification sheets directly to buyers evaluating a supply relationship. Request a quotation or contact our team to receive our full technical specification documentation.