This report has been written as part of the project Grön BoStad Stockholm, which is funded by the European Regional Development Fund. The project has been performed by IVL Swedish Environmental Research Institute. IVL Swedish Environmental Institute has, together with CleanBioHeat AB, conducted measurements of flue gas condensate from a pellet-fired boiler equipped with Flue Gas Recovery Unit (FGR) for flue gas cleaning and increased heat recovery. In a previous study of similar boilers and FGR high concentrations of some metals were measured in the flue gas condensate, whereby an additional purification step, an ion exchanger, was introduced in a new installation. In this study, the presence of toxic compounds was analyzed both before and after the ion exchanger. The purpose of the measurements was to provide a basis of analysis data for assessing the possibility of releasing the condensate to the water recipient via the urban stormwater, primarily for the boiler and FGR equipped with ion exchanger, but also to contribute to a larger base of measurements that can be used for future installations of the technology. In the report the technology of the FGR is briefly described and measurement methods and results are reported. Comparisons between measured concentrations and limit values for surface water according to the EU: s so called water directive and guideline values for emissions to stormwater systems and recipients are made. The conclusion from the investigations of this boiler with FGR is that neither PAH, metals, pH nor TOC should cause any obstacle to the emission of the flue gas condensate directly to the water recipient. This is evidenced by the fact that Microtox analysis did not detect any toxicity either before or after the ion exchanger. In the case of the nutrients nitrogen and phosphorus, the concentrations in the flue gas condensate were higher than the guideline values for what can be released to stormwater according to three of the major instances who have issued guidelines; Northwest Skåne, the Gothenburg Environmental Management and the regional stormwater network in Stockholm County.
CleanBioHeat har utvecklat en produkt, FGR®, som renar rökgaser från värmepannor samtidigt som den ger en ökad en värmeutvinning. Då den används på mindre pannor kan den hjälpa exempelvis kursgårdar/hotell, växthus och mindre fjärrvärmeanläggningar att minska sin miljöpåverkan. Vid reningen hamnar en del av partiklarna från luften istället i kondensvattnet och i detta projekt har IVL hjälpt CleanBioHeat med kemiska analyser för att bättre kunna bedöma om kondensaten är rena nog att släppas ut till dagvatten och sjöar.