Understanding how to use pellets in practice

Many of our readers are interested in how to use pellets, whether they can be used to heat conventional solid fuel boilers and stoves. The questions relate to all types of pellets, including, so far, rarely used lignin pellets, but providing a high heat capacity during combustion.

The fact is that when burning pellet fuel in classic heating devices (without a burner), the ash content can reach 60%. Moreover, the initial ash content of the pellets does not exceed 5%. The thing is that ordinary stoves cannot provide the required combustion intensity and pyrolysis afterburning of fuel, as is implemented in pellet burners.

The most important characteristics of pellets: heat capacity and ash content

For the manufacture of pellets, any raw material can be used, up to garbage and animal excrement. In this case, the resulting granular fuel will differ in heat of combustion and ash content. These are the most important characteristics of this energy raw material.

European standards

Only pellets with an ash content of 0.5-0.7% can be supplied to the European market according to EN Plus A-1 and EN Plus A-2 standards. In practice, on sale in Ukraine, you can find many offers of fuel pellets with an ash content of 4-5%. As a rule, high ash content is characteristic of high-heat-consuming raw materials, but not always. For example, wood pellets give 18-23 MJ / kg of heat, but do not exceed the ash content of the EN Plus A-1 and EN Plus A-2 standards.

Ukrainian market

Pellets from sunflower husks are especially popular on the Ukrainian market. Their ash content is 3% with a heat generated during combustion of 21 MJ / kg. This figure is comparable to brown coal. Lignin pellets have a higher heat capacity, their heat of combustion is 5500 kilocalories and is comparable to the characteristics of Anthracite walnut coal. At the same time, the ash content is higher - 10%.

The higher the ash content, the greater the requirements for heating equipment. Even pellet burners must be equipped with a cleaning system. When using wood pellets with low ash content, you can purchase cheaper pellet equipment, and use catalytic pellets for cleaning.

In addition, when burning lignin in furnaces and solid fuel boilers an unpleasant odor will be felt, the fuel cakes quickly, and the lignin dust generated carries explosive risks. These features are typical for other types of fuel, but specific combustion conditions, which, for example, are provided by FOCUS pellet flare burners and high-tech models of other manufacturers, fight these problems with pyrolysis afterburning. This possibility is technologically unavailable in furnaces and conventional solid fuel boilers.

For this reason, all the same, pellet granules should be used for their intended purpose, in pellet boilers or in boilers with  pellet burners.

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How to use pellets? How to replace firewood in boilers and ovens

Fuel briquettes can be used to heat stoves and boilers. However, it is worth paying attention to their purpose, as well as the mentioned characteristics - ash content and heat of combustion. With high ash content, furnaces and boilers must be cleaned regularly, as the carbon deposits formed have low thermal conductivity. As a result, the already low efficiency of economy-class boilers and furnaces is reduced.

Competent use of classic heating devices implies the choice of low-ash fuel and the use of catalytic cleaning by burning special granules and additives.