• Energy Research

There is currently great general interest in reducing the use of fossil-based materials. Fossil-based tarps are still widely used as cover for wood chip storage piles, causing additional waste or requiring further waste treatment in the supply chain. This study aimed to investigate the performance of an innovative bio-based wood chip pile cover compared to conventional treatments (plastic-covered and uncovered) in eastern Finnish conditions. The experiment evaluated the drying process during the storage of stemwood chips during 5.9 months of storage. It included the developments of temperature, moisture content, heating value, energy content, basic density, particle size distribution, and the dry matter losses of a total of six piles. As a result, the forest stemwood chips dried by 11%, with dry-matter losses of 4.3%, when covered with the bio-pile cover. Using the plastic covering, the forest stemwood chips dried by 22%, with dry matter losses of 2.9%. At the end of the experiment, the energy content in plastic-covered piles was 6.1% higher than uncovered piles and 3.1% higher than bio-pile-covered piles. While differences in the key drying performance parameters can be observed, the differences between uncovered piles and those covered with plastic tarps, as well as between the bio-based and the uncovered piles, were not statistically significant. We conclude that the bio-based cover, under the studied conditions, do not render better storage conditions than in current practices. However, our study indicates possible fossil-substitutional benefits by using a bio-based cover, which calls for further R&D work in this matter.

There is currently great general interest in reducing the use of fossil-based materials. Fossil-based tarps are still widely used as cover for wood chip storage piles, causing additional waste or requiring further waste treatment in the supply chain. This study aimed to investigate the performance of an innovative bio-based wood chip pile cover compared to conventional treatments (plastic-covered and uncovered) in eastern Finnish conditions. The experiment evaluated the drying process during the storage of stemwood chips during 5.9 months of storage. It included the developments of temperature, moisture content, heating value, energy content, basic density, particle size distribution, and the dry matter losses of a total of six piles. As a result, the forest stemwood chips dried by 11%, with dry-matter losses of 4.3%, when covered with the bio-pile cover. Using the plastic covering, the forest stemwood chips dried by 22%, with dry matter losses of 2.9%. At the end of the experiment, the energy content in plastic-covered piles was 6.1% higher than uncovered piles and 3.1% higher than bio-pile-covered piles. While differences in the key drying performance parameters can be observed, the differences between uncovered piles and those covered with plastic tarps, as well as between the bio-based and the uncovered piles, were not statistically significant. We conclude that the bio-based cover, under the studied conditions, do not render better storage conditions than in current practices. However, our study indicates possible fossil-substitutional benefits by using a bio-based cover, which calls for further R&D work in this matter.

AbstractThe EU should produce 20% of their energy from renewable sources, including bioenergy, by 2020. Each member state has their own target, for example, Finland should produce 38% and Sweden 49% of their energy from renewable sources by 2020. In this context, the development of forest energy utilization and more effective and economic supply systems plays an important role in both countries. The Nordic countries are the world leaders in the utilization of forest biomass for energy production. This paper provides a short overview of the driving forces behind the current technical solutions of forest energy procurement systems in Finland and Sweden and some perspectives on possible future developments. At the moment, the by‐products from forest industries (e.g., sawdust, black liquor) have a high degree of utilization in both countries. Additional raw materials for energy production include logging residues, stump and root wood, small diameter wood, and other wood not in demand by the traditional forest industries. Forest energy supply chains may be characterized based on the location of comminution into roadside comminution, terminal comminution, or comminution at a plant. The productivity of the generally highly sophisticated and costly procurement machinery is, to a large extent, dependent on the operator's skills and thus new technological solutions should be developed to improve their usability and consequently efficiency.This article is categorized under: Bioenergy > Economics and Policy

AbstractThe EU should produce 20% of their energy from renewable sources, including bioenergy, by 2020. Each member state has their own target, for example, Finland should produce 38% and Sweden 49% of their energy from renewable sources by 2020. In this context, the development of forest energy utilization and more effective and economic supply systems plays an important role in both countries. The Nordic countries are the world leaders in the utilization of forest biomass for energy production. This paper provides a short overview of the driving forces behind the current technical solutions of forest energy procurement systems in Finland and Sweden and some perspectives on possible future developments. At the moment, the by‐products from forest industries (e.g., sawdust, black liquor) have a high degree of utilization in both countries. Additional raw materials for energy production include logging residues, stump and root wood, small diameter wood, and other wood not in demand by the traditional forest industries. Forest energy supply chains may be characterized based on the location of comminution into roadside comminution, terminal comminution, or comminution at a plant. The productivity of the generally highly sophisticated and costly procurement machinery is, to a large extent, dependent on the operator's skills and thus new technological solutions should be developed to improve their usability and consequently efficiency.This article is categorized under: Bioenergy > Economics and Policy

Sustainably managed forests provide renewable raw material that can be used for primary/secondary conversion products and as biomass for energy generation. The potentially available amounts of timber, which are still lower than annual increments, have been published earlier. Access to this timber can be challenging for small-dimensioned assortments; however, technologically improved value chains can make them accessible while fulfilling economic and environment criteria. This paper evaluates the economic, environmental and social sustainability impacts of making the potentially available timber available with current and technologically improved value chains. This paper focuses on increasing the biomass feedstock supply for energy generation. Quantified impact assessments show which improvements - in terms of costs, employment, fuel and energy use, and reduced greenhouse gas emissions - can be expected if better mechanized machines are provided. Using three different methods - Sustainability Impacts Assessment (SIA), Life Cycle Assessment (LCA), and Emission Saving Criteria (ESC) - we calculated current and innovative machine solutions in terms of fuel use, energy use, and greenhouse gas emissions, to quantify the impact of the technology choice and also the effect of the choice of assessment method. Absolute stand-alone values can be misleading in analyses, and the use of different impact calculation approaches in parallel is clarifying the limits of using LCA-based approaches. The ESC has been discussed for the recast of the Renewable Energy Directive. Potential EU-wide results are presented.

Sustainably managed forests provide renewable raw material that can be used for primary/secondary conversion products and as biomass for energy generation. The potentially available amounts of timber, which are still lower than annual increments, have been published earlier. Access to this timber can be challenging for small-dimensioned assortments; however, technologically improved value chains can make them accessible while fulfilling economic and environment criteria. This paper evaluates the economic, environmental and social sustainability impacts of making the potentially available timber available with current and technologically improved value chains. This paper focuses on increasing the biomass feedstock supply for energy generation. Quantified impact assessments show which improvements - in terms of costs, employment, fuel and energy use, and reduced greenhouse gas emissions - can be expected if better mechanized machines are provided. Using three different methods - Sustainability Impacts Assessment (SIA), Life Cycle Assessment (LCA), and Emission Saving Criteria (ESC) - we calculated current and innovative machine solutions in terms of fuel use, energy use, and greenhouse gas emissions, to quantify the impact of the technology choice and also the effect of the choice of assessment method. Absolute stand-alone values can be misleading in analyses, and the use of different impact calculation approaches in parallel is clarifying the limits of using LCA-based approaches. The ESC has been discussed for the recast of the Renewable Energy Directive. Potential EU-wide results are presented.

The aim of this study was to analyze the effects of intensive management and forest landscape structure (in terms of age class distribution) on timber and energy wood production (m3 ha−1), net present value (NPV, € ha−1) with implications on net CO2 emissions (kg CO2 MWh−1 per energy unit) from energy wood use of Norway spruce grown on medium to fertile sites. This study employed simulations using a forest ecosystem model and the Emission Calculation Tool, considering in its analyses: timber (saw logs, pulp) and energy wood (small-sized stem wood and/or logging residuals for top part of stem, branches, and needles) from the first thinning and harvesting residuals and stumps from the final felling. At the stand level, both fertilization and high pre-commercial stand density clearly increased timber production and the amount of energy wood. Short rotation length (40 and 60 years) outputted, on average, the highest annual stem wood production (most fertile and medium fertile sites), the 60 year rotation also outputted the highest average annual net present value (NPV with interest rates of 1–4%). On the other hand, even longer rotation lengths, up to 80 and 100 years, were needed to output the lowest net CO2 emissions per year in energy wood use. At the landscape level, the largest productivity (both for timber and energy wood) was obtained using rotation lengths of 60 and 80 years with an initial forest landscape structure dominated by older mature stands (a right-skewed age-class distribution). If the rotation length was 120 years, the initial forest landscape dominated by young stands (a left-skewed age-class distribution) provided the highest productivity. However, the NPV with interest rate of 2% was, on average, the highest with a right-skewed distribution regardless of the rotation length. If the rotation length was 120 years, normal age class distribution provided, on average, the highest NPV. On the other hand, the lowest emissions (kg CO2 MWh−1a−1) were obtained with the left-skewed age-class distribution using the rotation lengths of 60 and 80 years, and with the normal age-class distribution using the rotation length of 120 years. Altogether, the management regimes integrating both timber and energy wood production and using fertilization provided, on average, the lowest emissions over all management alternatives considered.