Wood pellets are widely recognized as one of the most eco-friendly types of fuel nowadays. It means that their quality could reduce the greenhouse gas emissions of the energy production industry. What is more, getting wood residues from completely renewable sources leads to the preservation of millions tons of biomass.
However, torrefied wood pellets are considered as a new future of the fuel market. Thus, torrefied biomass is a relatively consistent and uniform product that could be burned at power plants, functioning much like coal. Herewith, it also helps to lower greenhouse gas emissions and much lower air pollution.
Wood Pellet disadvantages
However, there are some disadvantages of wood pellets. Thus, the initial costs should be spent on buying and installing the boiler. What is more, it is needed to be spent some time on cleaning boilers and empting ash bins on regular basis. Wood biomass is much bulkier than other types of fuel, so it is needed a lot of space (hopper or wood store) to store wood pellets dry.
And the most important, if you want to be really eco-friendly, you should check out availability of wood pellet in your region, as the further pellets are transported the greater amount of carbon is released while transporting.
Advantages of torrefied wood pellets
Torrefied wood pellets are widely used by power plants due to its functioning much like coal and high level of energy density.It should be noted that industrial wood pellets are burned less efficiently than torrefied wood pellets. Thus, torrefied wood pellets could retain up to 90% of the original biomass energy. As a result, coal plants on torrefied wood granules could operate at closer to their maximum capacity.
A higher level of bulk and energy density allows pelletized torrefied wood be much more economical to ship and transport in comparison with regular wood pellets. In addition, the hydrophobic ability of torrefied biomass makes it less likely to degrade than regular wood granules, making pellets easier to store.
The caloric value of torrefied biomass is 1.5 times higher than the level of caloric value of wood pellets. The moisture content of the torrefied wood pellets is around 1%, while the moisture content of wood pellets could reach 10 and more percent. So, torrefied wood pellets reduce the use of fossil fuel and allow coal power plants to lower GHG emissions, improving air quality.
Torrefied wood pellets: drawbacks
The analysts of Ukrainian Biofuel Portal pellets.wood.com described some disadvantages of the torrefied biomass. For the first, torrefied wood pellets are more difficult to find in comparison with regular wood pellets, as torrefied wood pellet industry has not been so widely developed yet. Other drawbacks are linked with the process of making torrefied pellets. Thus, CO2 emissions are connected with temperature and time the process takes. Each type of wood has its ideal burning temperature and burning wood at a higher or lower temperature could increase emissions and make a lower energy yield. And still, so many uncertainties about the torrefaction are needed to be explained.
So, according to the above information, both wood pellets and torrefied wood pellets are used for heating and generating electricity. Wood pellets as well as torrefied wood pellets are carbon neutral and recognized as a renewable fuel that improves air quality, reducing greenhouse gas emissions. But which one is a greener type of fuel?
As far as we now, torrefied wood pellets have a much higher heat content than regular wood pellets. Its water-repellent property has a great positive influence on moisture problems that appears while storing fuel in comparison with wood pellets. Torrefied biomass could be co-fired along with coal, allowing coal-fired power plants comply with renewable energy standards. To have a higher energy content means that it will be needed less pellet shipments, what much reduces CO2 emissions while transporting pellet fuel to customers. And the most important benefit of the torrefied biomass is that it could be used industrial bi-product from forestry sawmills or furniture manufacturers for torrefaction. Otherwise, they go into landfill and release methane, which has much higher negative environmental impact than CO2 emissions.