A team of researchers from the University of Zagreb in Croatia has highlighted a promising, though still evolving, solution for hard-to-abate sectors - enhanced wood pellets made through thermal pre-treatment.
According to findings published in the peer-reviewed journal Drvna Industrija, standard wood pellets are already seen as a cleaner fuel source than coal. However, they often underperform when compared to coal in key areas such as calorific value and storage stability.
The research, led by Marin Dujmović and colleagues from the Faculty of Forestry and Wood Technology, examines how techniques like torrefaction and steam explosion can significantly improve the fuel quality of wood pellets.
These thermal processes reduce the moisture content of woody biomass, increase its energy density and make it more stable in storage.
Importantly, the treated pellets more closely mimic the combustion properties of coal and can potentially be used in existing coal-fired infrastructure with minimal modifications.
The researchers note that while these pre-treatments offer both energy efficiency gains and improved pellet performance, they may come with considerable capital investment requirements — particularly at industrial scale.
"This review provides a concise overview of thermal pre-treatment technologies, necessary parameters, their impact on treated woody biomass, as well as final characteristics of treated woody biomass," the authors concluded.
Croatian researchers explore upgraded biomass for coal replacement
