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In this paper we present recommended revisions of emission factors for Norwegian wood stoves. Emission factors exist for a number of emissions to air, and vary in a wide range between individual studies depending on the technology, operating condition and fuel studied. This is a challenge when authorities need to decide on emission factors for inclusion in national emission inventories. In these inventories, emission factors need to be representative on a national level and include firing habits and technology in use. Herein lies a considerable challenge, resulting in large uncertainties for a number of the emission factors. In addition, value chain analysis is becoming increasingly common to assess the influence of the different elements in the value chain on different impact factors or stressors. For the wood stove value chain, the conversion element, i.e. the combustion process and the resulting emissions, is most important for most of the impact factors. It is essential for the outcome of such analyses that the best available emission factors are used to be able to assess the current impact of these as well as the improvement potential. Hence, it becomes increasingly important to select or derive representative emission factors, at a sufficient detailing level. In this work, recommended emission factors for wood stoves to be used in Norwegian value chain analysis are proposed. [ABSTRACT FROM AUTHOR]

In an attempt to look at means for reduction of corrosion in boilers, combustion experiments are performed on demolition wood with kaolin as additive. The experiments were performed in a multi-fuel reactor with continuous feed of pellets and by applying staged air combustion. A total characterization of the elemental composition of the fuel, the bottom ash and some particle size stages of fly ash was performed. This was done in order to follow the fate of some of the problematic compounds in demolition wood as a function of kaolin addition and other combustion-related parameters. In particular chlorine and potassium distribution between the gas phase, the bottom ash and the fly ash is reported as a function of increased kaolin addition, reactor temperature and air staging. Kaolin addition of 5 and 10% were found to give the least aerosol load in the fly ash. In addition, the chlorine concentration in aerosol particles was at its lowest levels for the same addition of kaolin, although the difference between 5 and 10% addition was minimal. The reactor temperature was found to have a minimal effect on both the fly ash and bottom ash properties. [ABSTRACT FROM AUTHOR]

Climate impacts of forest bioenergy result from a multitude of warming and cooling effects and vary by location and technology. While past bioenergy studies have analysed a limited number of climate-altering pollutants and activities, no studies have jointly addressed supply chain greenhouse gas emissions, biogenic CO 2 fluxes, aerosols and albedo changes at high spatial and process detail. Here, we present a national-level climate impact analysis of stationary bioenergy systems in Norway based on wood-burning stoves and wood biomass-based district heating. We find that cooling aerosols and albedo offset 60-70% of total warming, leaving a net warming of 340 or 69 kg CO 2 e MWh -1 for stoves or district heating, respectively. Large variations are observed over locations for albedo, and over technology alternatives for aerosols. By demonstrating both notable magnitudes and complexities of different climate warming and cooling effects of forest bioenergy in Norway, our study emphasizes the need to consider multiple forcing agents in climate impact analysis of forest bioenergy.