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Wood pellets

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First of all, wood pellets are widespread worldwide due to peculiarities of the combustion process.

First of all, wood pellets are widespread worldwide due to peculiarities of the combustion process.

There are two widespread terms in English such as “Wood pellets” and “Holz-Pellets” or “Holzpellets”, and several Russian terms such as “Biogranuly”, “Toplivnye granuly”, “Biomassa”, “Opilochnye granuly”, but the most correct term as “Wood pellets”, or simply “Pellets”, as a variety of alternative industrial fuel has appeared relatively recently.

Worldwide widespread pellets primarily obtained due to the peculiarities of the combustion process. During the combustion process the amount of heat (calorific value) of wood pellets is comparable to conventional fuels, while the amount of harmful substances emissions remains insignificant.

For instance, the amount of heat generated from fossil coal combustion is equivalent to the amount of heat generated from combustion of the same amount of wood pellets but the incombustible residue (ash) remaining after combustion of pellets (up to 1,5 %) is incomparably small then the residue after coal combustion (up to 50 %). What are wood pellets?

Wood pellet is a standardized cylindrical pressed product from dried residual wood, such as dust from operation of woodworking machines, chips and remnants of forest wood. Wood pellets are produced without chemical fixers under a high pressure.

Wood pellet length is about 20-50 mm, diameter is 4-10 mm.

Production Methods

Since emergence in 1947, the production method of wood pellets has changed a little.

The process of granulation (pelletizing) itself takes place in the specific ring dies (die molds) by rotating rotary forge rollers which press steam activated chipped raw wood into numerous holes (die molds), and then pellets cut from the outside of ring dies by a special knife are cooled down and separated from fine particles.

Considering the whole production process, it can conventionally be divided into several stages:

  1. Primary crushing of chips, shavings in the chipping machines until a homogeneous mass is obtained;
  2. Drying of the resulting mass;
  3. Final mass crushing – refining process;
  4. Pressing (granulating - pelletizing);
  5. Cooling down (conditioning);
  6. Separation (separation of substandard fraction from the full-size granules).

It is worth repeating that pellets are made without chemical fixers!

Wood pellets are not a new raw material. Back in the 19th century, the houses were heated by chips and shavings, and for their transportation and storage the mass was compacted.

In 1996, wood pellets were for the first time certified in Germany as a kind of fuel. Why do we have nowadays such an interest in wood pellets?

We can identify several major factors:

As wood derivatives, wood pellets are renewable raw materials as opposed to oil or gas.

High calorific value of wood pellets is equal to 5 kW/ h per kg, while the power content of one kilogram of wood pellets is equal to half a liter of liquid fuel (diesel fuel).

Density of Pellets

Pellets have a high bulk density, thus, they do not require a lot of space for storage.

Price of Wood Pellets

Wood pellets have a high competitiveness on the market. Prices for wood pellets are significantly lower than the prices of other traditional fuels under comparable consumer properties.

It is especially required to emphasize the factors positively influencing the environment:

Reduction of Greenhouse Effect

Released carbon dioxide CO2 in wood pellets is designated as “neutral”. Tree releases as much CO2 as it absorbed during its growth (closed carbon exchange). During combustion of fossil fuels, on the other hand, carbon dioxide collected over millions of years is released. This leads to an increase in CO2 in the atmosphere and, consequently, to anthropogenic greenhouse effect.

When reducing acid rain in addition to the reduction of carbon dioxide emissions when using wood pellets as fuel, there is a decrease in emissions of sulfur dioxide. This in its turn leads to the reduction of acid rain and to the reduction of forest destruction. The use of wood as a raw material, wood pellets as a fuel ultimately protects our forests!

Reduction of Transportation Risk

Environmental pollution because of such misfortunes like holes in oil tankers, accidents on pipelines, at power plants, including nuclear power plants, completely disappear when using wood pellets, and the danger of explosions, accidents, spillage of fuel, harmful emissions is simply minimal in comparison with fossil fuels.

Minor combustion wastes

Combustion ash can be used as fertilizer or insignificant garbage. Ash is only 1.5% of the fuel mass. Ash is removed in modern furnaces and boilers every two years.

Comparative schedule of CO2 environmental emissions (gr./ kW per hour) by different heating systems (electric ones, operating on light diesel, gas and pellets). What is more, the figures are based on the emissions of CO2 required for the production of fuel. As the phrase goes: no comments!

We can give you an example.

If a family of three people living in a separate house replaces the boiler operating on diesel fuel with the boiler operating on wood pellets, this will free the atmosphere of 5 tons of carbon dioxide emissions per year, and if to replace the boiler operating on gas with the boiler operating on wood pellets, the reduction of harmful emissions will be 2,5 tons per year.

Application field

Wood pellets are used in many industries and in everyday life. They are used as a cat litter, as an absorbent in the chemical industry, as a filler in systems for meat and fish smoking, as an excellent fuel for shish kebab. However, the main application field of wood pellets is still the thermal power industry. Combustion of pellets in industrial and household boilers to generate heat and electricity is widely spread.

Contacts

  • 220049,  Minsk, 17 Knorina Str.
  • +375 29 6758332
  • oksana@belpellet.by