Just as the European Union institutions are nearing a crescendo in their debate about the use of forest biomass for energy, the Royal Swedish Academy of Agriculture and Forestry (KSLA) seems to send a message in support for smart bioenergy in its 2018 Award for Best PhD Thesis.
Characterisation and Densification of Carbonised Lignocellulosic Biomass, published in 2016 by the Swedish University of Agricultural Sciences at Umeå, is about just that. It investigates whether biomass from forestry residues or willow that has been pre-treated by various degrees of roasting, or torrefaction, can be turned into qualitative pellets.
However, he told Bio4Energy Communications, the process requires greater fine-tuning compared with pellet making based on untreated sawdust, which is usually the basis for making so-called white pellets.
“We have seen that it works, yes. The next step is the creation of a market for torrefied pellets. The problems related to the pelletisation process itself can be solved”, Rudolfsson said.
“However, we generally say that the [torrefied] materials are a little less forgiving when it comes to process variations… in terms of press length and moisture content, for instance. Just as the raw biomass materials, the torrefied materials have very different characteristics. This is something that is definitely relevant in the pellet-making process. Torrefied spruce [wood] worked better than torrefied fir, for instance”.
The idea behind the whole undertaking has been to develop a product—a dark pellet based on carbonised biomass—that has similar properties to hard coal. This could help bridge the gap in the transition to a total phase out of fossil fuels, the researchers believe. Initially, the renewable and the traditional fuel could be used together as a mixed fuel suitable for use in existing combined heat and power installations, but with less polluting emissions going up the chimney.
The KSLA awards its PhD prize once a year at a glittering ceremony in Stockholm, Sweden, in the presence of Swedish royalty. This year, 28 January, Rudolfsson stepped up to the podium to accept his award, a diploma and a personal grant, from the hands of the Swedish marshal of the realm, professor Svante Lindqvist.
“It is nice to be acknowledged for one’s work. The setting, the glamorous ceremony, makes it feel all the more important. To think that someone took pains to nominate me also makes me happy”.
KSLA prize motivation (freely translated from Swedish):
“In his PhD thesis, Magnus Rudolfsson has analysed and developed methods for the pelletisation of torrefied biomass from lignocellulose, from not only bi-products such as branches and tops, but also from energy crops such as willow and canary-reed grass. For instance, he shows that pelletisation of torrefied biomass requires greater precision than traditional pelletisation. Therefore, in his work Magnus Rudolfsson developed different ways of tackling critical pitfalls in the process. The innovative research that Magnus Rudolfsson puts forward is an important contribution to the realisation of a bioeconomy and the promotion of an increased use of renewable biofuels.”