Systems Analysis of Biomass Flows A Case study of Borås

Abstract: The systems analysis of biomass in the Borås municipality is conducted so as to identify the amount of biomass consumed by certain designated systems for this study. Using the principles of urban metabolism and material flow accounting, the system boundary is setup and biomass is categorized into system specific entities which are to be quantified. The symbiosis principle and the cascading approach of resource utilization are used to determine the systems which are working together and the resources they share among each other. Selected flows are established to be calculated for paper and paper products; fuel and construction wood; biogas; and blended transportation fuels. The flows are considered one by one, it is found that the consumption system and the waste management system are main players in the flow of paper and its products. The flow of fuel and construction wood is surveyed across different companies in the municipality for 2013. The fate of the waste construction wood for 2011 is traced across the waste handling systems of Borås Energi och Miljö till the Combined Heat and Power plant at Ryaverket. The quantities of fuel wood consumed by the CHP and residential heat are received from statistical sources. The main players in the biogas production flow are the waste management system and the digesters at Gässlösa and Sobacken. The consumption of enriched biogas is then examined for different transportation sub-systems. The flows for blended fuels is considered for petrol, diesel; separately analysed from them are their blended quantities of ethanol and other renewable additives. The sold quantities of petrol and diesel have been received from the market survey for the year 2013. The flows are then individually validated by common critical parameters to determine how reliable the information sources are. The resulting flows are discussed for the symbiosis of resources and significance of urban metabolism concepts.