Agropellets, mix pellets and wood pellets - what is the difference

At the time of buying pellet burner, of course, the question arises, what kind of pellets can and should be used? For this reason, our specialists have made an analysis of the raw materials available on the market with a description of the main characteristics. Mixed pellets, agropellets and, accordingly, wood pellets are on sale. They differ in feedstock, heat capacity, ash content and heat transfer.

On average, the price of pellets on the Ukrainian market ranges from 2200 UAH. up to EUR 100 per ton. We have deliberately indicated the cost in this way, with an emphasis on suppliers focused on Europe. If you are interested in switching to agro or wood pellets, keep in mind that pellets are considered the most promising renewable fuel. The projected consumption volume will increase by about 2 times by 2030. But today the offer is quite wide, and over time it will expand due to the expansion of the raw material base and waste processing.

Pellet quality indicators

For the manufacture of pellets, wood chips and other sawn timber waste can be used. On the Ukrainian market, granules with a moisture content of 8-10% are offered, and the requirement for the moisture content of raw materials is 8-15%. In the process, drying is carried out, which allows you to reduce weight, improve the heat capacity of the fuel and other indicators.

The most important indicator is ash content. Ukrainian producers supply granular fuel with an ash content of 4-5%, but according to the EN Plus A-1 standard, this figure should not exceed 0.5-0.7%. The higher the ash content, the greater the requirements for heating equipment and its cleaning.

If the cleaning system pellet boiler not automatic, it is better to take pellets with lower ash content. At the same time, keep in mind that the European standards for certificates ENplus A1 or A2 describe the requirements for granular fuels for private houses. However, these requirements do not apply to Ukraine.

The most important indicator is the heat of combustion of the fuel. It can be specified in kilocalories and Joules. Moreover, the heat capacity of the fuel does not always correspond to a low ash content.

If we talk about specific pellet burners, then volumetric combustion in FOCUS modules provides maximum efficiency. Moreover, regardless of the quality of the fuel. In fact, you can use the cheapest pellets to generate heat without gas and without loss of heat capacity. Wood pellets will give a little more benefit, but also provide minimal ash content. Which is important considering the cleaning of the equipment.

Still, the available fuel pellets differ in their technical characteristics. First of all, in terms of ash content and heat of combustion of fuel. These characteristics should be considered when choosing and purchasing equipment and fuels.

Wood pellets: their heat capacity and alternatives

Wood pellets were the first to appear on the market; their heat capacity remains one of the highest of all proposals with a low ash content. The heat of combustion of wood pellets is 18-23 MJ / kg with an ash content of 0.5-0.7%. This calorific value corresponds to the heat transfer of peat and brown coal.

For the manufacture of pellets from wood raw materials are used:

• shavings;
• wood chips;
• large wood waste;
• woody substandard.

Agricultural enterprises produce pellets from alternative raw materials. The most popular agropellets are straw pellets. They emit almost no CO2, no more than the plant received in the process of growth. In terms of heat capacity, straw pellets are inferior and give 16 MJ / kg. A similar agro-reproducible fuel is reed pellets, they generate 19 MJ / kg, but their ash content is higher and amounts to 4%.

Granules from sunflower husk are considered more profitable among agropellets. Their calorific value is comparable to coal and amounts to 21 MJ / kg with an ash content of 3%. Accordingly, to increase the efficiency, you can use this type of granular fuel, having thought out in advance the system for cleaning the burner and chimneys. Concerning pellet burners FOCUS, then they are designed for operation with various pellet fuels, including a pellet with a high ash content. And provide a mechanical or automatic cleaning system for the pellet boiler.

Other raw materials for pellets

For the production of granular fuel can be used:

• waste paper;
• chicken droppings;
• peat (21 MJ / kg with an ash content of 5%);
• lignin (21 MJ / kg with an ash content of 3%).

The volumetric combustion technology makes it possible to somewhat neglect the quality of the pellets. However, raw materials with a higher heat capacity will allow more heat to be obtained. In other words, wood pellets from waste of valuable wood species remain the most suitable.