Pellet quality parameters

Pellets have been used as fuel for a comparatively short time, borrowing the idea from the cattle industry, where compound feed had been used for a while. Pellets are a new, clean and natural type of locally-produced fuel, which utilizes modern technologies to make heating more comfortable and lucrative. Wood pellets are produced using sawdust and shavings, which were previously thought to be unusable by-products. Pressed at a ratio of 7:1, pellets are easy to transport and use as fuel, providing excellent heat output.

Nature-friendly and economically sound fuel

Unlike fossil fuels, pellets are CO₂ neutral, which means that during combustion the CO₂ emissions don’t exceed the amount absorbed during the growth of the biomass from which pellets are produced. Pellets are a renewable and inexhaustible resource, which causes no harm to the environment, as opposed to natural gas and petroleum products such as diesel fuel. At the same time, pellet heating systems are considerably easier and less expensive to install, and constant demand for wood materials ensures a steady supply of sawdust and other wood industry by-products from which pellets are produced. This guarantees stable low prices on pellets, ensuring savings for years to come.

In order for the heating boiler to reduce the frequency of maintenance and cleaning, and to ensure maximum boiler efficiency, proper pellets should be used. High quality pellets, although more expensive, will ensure appropriate boiler operation and generate savings in the long run, accounting to less fuel used and fewer maintenances needed.

GRANDEG heating boilers are compatible with wood pellets adhering to European standard EN14961-2 ENplus-A1. The TURBO series boilers can also be used with ENplus-aA2 standard pellets.

Criteria	Unit	EN plus-A1	EN plus-A2
Diameter	mm	6 or 8
Length	mm	3.15 ≤ L ≤ 40
Moisture content	%	≤ 10
Ash content	%	≤ 0.5	≤1.0
Mechanical strength	%	≥ 98.0 ≥ 97.5
Dust and small particle content (<3.15 mm)	%	< 0.5
Calorific value	MJ/kg	16.5≤ Q≤ 19	16.3≤ Q≤ 19
Bulk density	kg/m³	650 ≤ BD ≤ 750
Ash melting point	⁰C	≥ 1200	≥1100

Explanations:

Diameter – the burner and the feed system are meant for pellets 6 to 8 mm in diameter, non-standard sizes can cause problems in the pellet dispenser.
Length – non-standard length can interfere with proper burner and feed system functionality.
Moisture content – higher levels of moisture reduce the efficiency of the burning process, as part of the heat goes into drying the fuel itself, and the evaporated water also absorbs heat from the furnace, reducing temperature in the boiler.
Ash content – higher levels of ash content increase the frequency of cleaning, and can also result in the accumulation of residue and soot.
Mechanical strength – pellets with lower mechanical strength can disintegrate and crumble, accumulating dust and small particles.
Dust and small particle content – too much dust and small particles can cause blockage in the feed system.
Calorific value – higher calorific values mean that less fuel is needed for generating the same heat output.
Bulk density – appropriate bulk density ensures an even burning process and high mechanical strength.
Ash melting point – you should choose pellets with an ash melting point higher than the temperature inside the furnace to prevent the accumulation of melted ash.