- Written by Anna Strom
of energy systems applied to bioenergy have in common? Not much, it
could seem. However, in the research environment Bio4Energy they are inputs to developing a complete biorefinery value chain. To do so scientists work with industry to use forest-sourced biomass with maximal efficiency, devising methods for turning undesirable waste products into renewable energy or bio-based materials with a low environmental impact.
“We could bring ashes (or other byproducts of forestry or its process industries) back into the ecocycle after modification. This is an important part of Bio4Energy”, he said.
Take boron isotopes. They are being studied in B4E for their role as a signpost of boron distribution in trees, spruce and pine in this case, with the larger purpose of gauging what mineral concentrations makes for optimal tree health in what circumstances. This has implications not only for the quality of timber and forest-sourced biomass, but also for forest management. As it so happens, the life of boron isotopes in trees appears to be somewhat of a black hole in the scientific literature.
But let’s start from the beginning. Boron is a metalloid, or half metal, that works to strengthen the cell walls of plants, according to Wikipedia. Isotopes are variants of atoms of a particular chemical element, which have differing numbers of neutrons.
Boron is also one of the essential minerals, or nutrients, that trees and other forest vegetation need to grow and to gain hardiness, albeit in small amounts. While relatively little studied compared to nitrogen, which is widely used as a fertilising agent, boron—or rather its isotopes, which have the merit of allowing scientists to determine their approximate location in the tree—would seem a pertinent candidate for further investigation. According to Ingri, who specialises in the study of isotopes as a professor at the Luleå University of Technology in northern Sweden, there are several reasons for this.
An obvious one would be to gauge what amounts of nutrients make for healthy trees in a particular species and settings. For this researchers need to know the routes of distribution of each nutrient in the tree, their mechanisms of action and interactions with other substances. While scientists had been using isotopes to map these distribution “pathways” for nitrogen, it had not been done for boron, Ingri explained. Thus, today, when a forest manager spreads boron over a soil that he tends, to counter a deficiency, there are no scientifically established thresholds to guide him. "We could be adding too much or too little. We don’t know”, said Ingri.
What the scientists do know is that boron concentrations tend to be low where nitrogen additions and liming have been plentiful and that, especially inland, plants and trees are challenged by the fact that only little of the boron that exits the system by runoff or by other mechanisms is naturally replenished. Adding to the complexity of the management of boron, Ingri said, was the fact there was “only a very small window before the boron turns into a poison”. That is, the boron becomes toxic when concentrations increase past a certain threshold. Again, this has not been established.
So B4E researchers will want to start by ascertaining “how the boron (isotopes) redistribute in plants and trees” and, in a second step, try to “link this to nitrogen isotopes", according to Ingri. He is well placed to do so, having linked up with soils and water scientists Richard Lucas and Peter Högberg, of the Umeå-based branch of the Swedish University of Agricultural Sciences, and having access to the extensive records of the Norrliden experimental park, in northern Sweden, where trials of intensive nitrogen fertilisation have been running since the early 1970.
“A boron deficiency exists. We don’t know what amounts (of boron additions) are needed. That is something to look at. If there is a boron soil deficiency, there will be a deficiency in the timber. First it hits timber quality. There can be… acute effects in the (tree) tops (of conifers)”, Ingri explained;
“Very few studies have been done on this”, but because careful records had been kept at Norrliden, in theory “we (could) track the movement of boron through an ecosystem. This is really unique”.
Energy system analysis
“My research has concentrated on the analysis and optimisation in the field of energy systems, from component detail to system configuration, with a particular focus on the application of advanced computer science techniques to deal with some of the main problems in this broad field”, Toffolo, who became a professor at LTU this year, said in a note.
Toffolo has more than a decade of research behind him in energy engineering and the analysis of energy systems. Since gaining his PhD in energetics from the University of Padova in 2002, he held first a postdoctoral then a research fellowship at that university, before joining LTU, and B4E, in 2011. In 2007, he won the prestigious ASME Edward F. Obert Award for the “best (scientific) paper on thermodynamics”.
At the B4E Miniconference he outlined his plans to “continue devoting my efforts to the study of the optimal synthesis and integration of components in energy system configurations.
“The basic configuration obtained for a complex flowsheet (which mirrors a real-life process) brings to light the fundamental processes occurring in an energy system, which can be seen as the superimposition of elementary thermodynamic cycles. This methodology can be easily extended to process integration" in biorefinery.
“In my opinion, the Bio4Energy research project (is) a perfect framework for developing these ideas”, he concluded.
A recent scientific article by Toffolo and colleagues discusses one methodology that he might use when conducting research for B4E.