Emissions from Heating Plant burning Biomass in the interval 0.5 - 10 MW The emissions from the heating plants in the interval 0.5 - 10 MW, burning biomass, have been investigated. The measurements have included carbon monoxide, carbon dioxide, nitrogen oxides, a number of volatile organic compounds (VOC) and polyaromatic hydrocarbons (PAH). Wood chips, wood briquettes, straw, bark, wood pellets, wood powder and peat are the fuel quantities included in the survey. The measurements were made at existing operating conditions for each plant. No adjustments to the combustion equipment were made. The measurements showed that biomass combustion can give rise to high emissions of unburnt hydrocarbons. In six out of thirteen tests, significant VOC emissions with methande, ethylene, propene and acetlyene in the interval 5 - 500 mg/MJ were recorded. In all these cases the CO emissions exceeded 1000 mg/MJ. A correlation between increasing CO content and increasing VOC content was indicated in these cases. This is most apparent for methane, which is the most abundant VOC species. In the other cases, where the CO emissions were below 500 mg/MJ, no significant VOC emissions were recorded. NOx, emissions varied for all cases between 35 and 256 mg NO2/MJ. No clear correlation between low levels of unburnt hydrocarbons and high levels of NOx could be established.