Biogas
En systemanalys av Solna Stads matavfallsprocess
Global warming is a huge issue that humans have contributed to through over-exploitation of natural resources and extensive usage of fossil fuels. Now more than ever, we need to embrace a recycle thinking and reuse our waste, for example through producing biogas from our food waste. The purpose of this report was therefore to identify the energy usage and emissions resulting from the biogas chain which spans from Solna Stad to Uppsala Vatten. Furthermore, potential efficiency improvements were to be identified and proposed. This report focused mainly on the first part of the biogas chain that includes the collection of the food waste and the reloading process. Gathering of information was done through study visits, interviews and literature studies.The transports accounted for a large part of the emissions and energy use. A reduction of these can be achieved by switching to more environmental friendly fuels. The useful energy obtained was higher for the reference alternative compared to the biogas process. However, social benefits were obtained from the biogas in the form of a renewable fuel and environmentally friendly manure. The energy usage during the winter months was significantly higher in the reloading facility compared to the summer due to heat leakage. A reduction of this can be achieved by building an accompanying construction with a high speed door in front of the reloading facility.