Life cycle primary energy use and carbon emission of an eight-storey wood-framed apartment building

The complex fluxes between standing and harvested carbon stocks, and the linkage between harvested biomass and fossil fuel substitution, call for a holistic, system-wide analysis in a life-cycle pe...

Integrated carbon analysis of forest management practices and wood substitution

The significance of technical data, as well as the significance of system boundary choices, when modelling the environmental impact from recycling and incineration of waste paper has been studied by a life cycle assessment focusing on global warming potentials. The consequence of choosing a specific set of data for the reprocessing technology, the virgin paper manufacturing technology and the incineration technology, as well as the importance of the recycling rate was studied. Furthermore, the system was expanded to include forestry and to include fossil fuel energy substitution from saved biomass, in order to study the importance of the system boundary choices. For recycling, the choice of virgin paper manufacturing data is most important, but the results show that also the impacts from the reprocessing technologies fluctuate greatly. For the overall results the choice of the technology data is of importance when comparing recycling including virgin paper substitution with incineration including energy substitution. Combining an environmentally high or low performing recycling technology with an environmentally high or low performing incineration technology can give quite different results. The modelling showed that recycling of paper, from a life cycle point of view, is environmentally equal or better than incineration with energy recovery only when the recycling technology is at a high environmental performance level. However, the modelling also showed that expanding the system to include substitution of fossil fuel energy by production of energy from the saved biomass associated with recycling will give a completely different result. In this case recycling is always more beneficial than incineration, thus increased recycling is desirable. Expanding the system to include forestry was shown to have a minor effect on the results. As assessments are often performed with a set choice of data and a set recycling rate, it is questionable how useful the results from this kind of LCA are for a policy maker. The high significance of the system boundary choices stresses the importance of scientific discussion on how to best address system analysis of recycling, for paper and other recyclable materials.

Life cycle assessment of waste paper management: The importance of technology data and system boundaries in assessing recycling and incineration

Climate change, environmental impact and the limited natural resources urge scientific research and novel technical solutions. The monograph series Green Energy and Technology serves as a publishing platform for scientific and technological approaches to "green" i.e. environmentally friendly and sustainable technologies. While a focus lies on energy and power supply, it also covers "green" solutions in industrial engineering and engineering design. Green Energy and Technology addresses researchers, advanced students, technical consultants as well as decision makers in industries and politics. Hence, the level of presentation spans from instructional to highly technical. **Indexed in Scopus**.

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Green Energy and Technology

We estimate the climate effects of directing forest management in Sweden towards increased carbon storage in forests with more land set-aside for protection, or towards increased forest production for the substitution of carbon-intensive materials and fossil fuels, relative to a reference case of current forest management. We develop various scenarios of forest management and biomass use to estimate the carbon balances of the forest systems, including ecological and technological components, and their impacts on the climate in terms of radiative forcing. The scenario with increased set-aside area and the current level of forest residue harvest resulted in lower cumulative carbon emissions compared to the reference case for the first 90 years, but then showed higher emissions as reduced forest harvest led to higher carbon emissions from energy and material systems. For the reference case of current forest management, increased harvest of forest residues gave increased climate benefits. The most climatically beneficial alternative, expressed as reduced cumulative radiative forcing, in both the short and long terms is a strategy aimed at high forest production, high residue recovery rate, and high efficiency utilization of harvested biomass. Active forest management with high harvest levels and efficient forest product utilization will provide more climate benefit, compared to reducing harvest and storing more carbon in the forest.

Climate change effects of forestry and substitution of carbon-intensive materials and fossil fuels

Energy use and environmental impacts of forest operations in Sweden

Transportation of timber from forests to industrial sites consumes more fossil fuels than any other part of the Swedish wood supply chain. This paper compares the environmental performance and energy requirements of a range of possible long-distance transport strategies involving lorry or lorry-and-train combinations using a variety of potential fuels/energy carriers, including diesel-oil, coal, hydropower, nuclear fuel and biofuels. The total efficiency of the complete system (i.e. “well-to-wheel” efficiency) is considered. The results indicate that transport alternatives including railway transport require less process energy than options relying exclusively on road vehicles. However, calculations showed that by using biofuels instead of fossil fuel in a lorry, it is possible to replace 96% of the fossil energy.

Energy requirement and environmental impact in timber transport

A comparison is made of energy usage and the contribution made to the global warming potential (GWP) by present (1997) and past (1972) forestry operations (including secondary haulage) in Sweden. The results are expressed in units of one cubic metre (solid u.b.) of harvested timber. The results indicate that, since 1972, improvements in fully mechanized forestry operations, particularly logging, have led to a reduction in total energy use from 1972 (236 MJ). In fact, the energy used by today’s (1997) mechanized logging systems (147–200 MJ) is roughly the same as that used by motormanual systems back in 1972 (156–177 MJ). The same is true as regards the contribution made to global warming potential: more fossil carbon was released in mechanized forestry (22 GWP) in 1972 than in 1997 (13–17 GWP). What’s more, the contribution to GWP in 1997 is on the same level as that made by motormanual systems in 1972 (15–16 GWP). It is accepted that forest management in Sweden mitigates the global warming poten...

Eva-Lotta Lindholm

Papers

Energy use and environmental impacts of forest operations in Sweden

Energy requirement and environmental impact in timber transport

Energy Use in Swedish Forestry in 1972 and 1997

Energy use and environmental impacts of forest operations in Sweden [Journal of Cleaner Production 13 (2005) 33–42]