Kompostering av organiskt avfall från Gästrikeregionen ? miljöpåverkan av olika behandlingsalternativ
In the coming years, organic food waste will be collected in the region of Gästrikland, Sweden. The collection is planned to cover the entire region by the end of year 2007. To start with, smaller amounts are being collected and transported to a central composting plant in Sala. However, a central composting plant in the region of Gästrikland is projected.The objective of this thesis is to evaluate a number of possible methods for composting of organic food wastes regarding their environmental impacts and localization.There are four scenarios for future composting of organic waste that have been evaluated. There are two that consist of membrane composting, either in Sala or in the region of Gästrikland. The other two scenarios consist of tunnel composting in the region of Gästrikland with two possible placements.The result from the systems analysis shows a lower environmental impact when using tunnel composting, compared to membrane composting. As the tunnel compost uses technologies for treating the compost gas, the amount of substances that can contribute to acidification and eutrophication is considerably lowered. However, the use of electricity is higher since the automatic process demands a greater electricity input. At a membrane composting plant, vehicles are being used to move compost material. The combustion of diesel oil gives rise to gases that increase the global warming. According to future legislations, tunnel composting gives an easier control of the emissions and optimization of the compost process.