Lignin Pellets

Lignin pellets have a high calorific value and bulk density. In terms of calorific value, lignin pellets are comparable to charcoal, while the content of minerals and organic substances, heavy metals, as well as other impurities fully meets the standards of European industrial wood pellets in terms of the technical characteristics of fuel (defined in En 14961-1:2010)

Lignin is a carbon-neutral production method, because the carbon dioxide produced from its burning binds back to trees.

Lignin is an organic substance found in trees and plants. For example, in the production of methanol - also known as wood spirit - lignin and wood fiber are residual products of the process.

In the production of methanol, lignin and wood fiber are residual products of the process. In general, wood contains about 20-30% lignin. Different amounts of lignin in wood species affect how easily or difficult it is to separate lignin for energy use.

Lignin or black pellets have a high calorific value, they are a high calorific value, they are easy to store and their advantage is that they can be found in almost inexhaustible resources.

Lignin pellets have a good, high calorific value and are stable in long-term storage in terms of moisture absorption. Pellets have good water resistance because the lignin itself prevents water absorption like glue.

The calorific value obtained from wood pellets is about 16.5 MJ/kg, while lignin pellets have 25.26 MJ/kg.

Lignin is a binder that increases the mechanical strength of the material. Lignin binds the fibers of biomaterial together. In addition, lignin contains a lot of carbon and wheat, which are substances that produce a lot of heat.

Water resistant and can be store out doors.

The amount of sulfur (2-3%) must be taken into account when burning. In some cases, it can be used to prevent corrosion in boilers. The ash produced from combustion consists mainly of sodium (Na), which has a decreasing effect on the melting point of the ash.

It has been tested that lignin can be burned in a normal boiler, where oil is normally burned.

Lignin dust is so fine and small that it works in the same way as burning oil, where small droplets are formed from the oil. Possible boilers for burning lignin pellets could be those in which wood pellets are also burned.

Pellets are often placed in an old oil boiler, in which case the efficiency of the old boilers must be taken into account.

In terms of efficiency it usually get about 70-80%, if the temperature of the flue gases does not rise above normal. It is possible to get a higher efficiency, but then the temperature of the flue gases must be increased.

In general, however, old oil boilers have enough efficiency, even for winter energy needs. Lignin pellets can be burned like wood pellets with oil and coal in co-combustion.

Before going to the boiler, the pellets are crushed together with the coal into a dust mixture. In co-firing, the boiler may get dirtier than normal, but this way of burning can reduce greenhouse gas emissions.

Turun Energia was the first in Finland to use pellet and coal co-firing, where coal was replaced by 10-15 m-% pellets.

Helen's Hanasaari and Salmisaari power plants adopted the method in 2015 and 2017.

In Sweden, the Hässelbyverket power plant has used co-firing of wood pellets and oil since 1998.

The use of lignin will increase especially as a replacement for fossil fuels in the future due to its good calorific value.