Pellet Production: Impact of Pollutants and Associated Health Risks

The current energy crisis, together with the depletion of fossil fuels and climate change, has made it essential to find alternative energy sources that are both economically sustainable and environmentally friendly. Renewable energy resources represent sustainable strategies for reducing the use of fossil fuels. Biomass is used to produce heat, electricity or biofuels through combustion or conversion. Most biomass comes from wood. The introduction of pellets in the bioenergy market aims to reduce environmental emissions, offering an alternative solution to polluting energy sources. In recent years, the trade and use of wood pellets as fuel has increased steadily, making the quality of the pellets essential to limit air pollution. Recent studies show that the use of pellets produces pollutants such as benzene and its derivatives, as well as heavy metals. Inhaling these substances causes an increase in the amount of reactive oxygen species within the body, with potentially harmful effects on human health. The impact of pellet use on air pollution and health was evaluated through the analysis of raw materials, sampled according to the UNI EN ISO 18135:2018 standard. In this study, the analysis of inorganic fractions, carried out with ICP-AES, showed that the most abundant elements are calcium, potassium and magnesium. The analysis of organic fractions, on the other hand, carried out with GC-MS, raised concerns about the presence of formaldehyde, an indication of the use of unsuitable raw materials. Statistical analysis confirmed that the inorganic fraction is fundamental for the quality of the pellets, but also highlighted that the organic fraction should not be neglected. The adoption of UNI EN ISO 17225 has led to an improvement in pellet quality, in particular by increasing its calorific value and reducing emissions into the environment. However, current regulatory gaps require further action to protect the environment and human health.