Energy Modeling for an Eco-City with focus on Biogas Potential

Sammanfattning: The Sino-Swedish Eco-City in Wuxi is the result of collaboration between the Chinese local government and several Swedish stakeholders aiming to create a sustainable urban infrastructure comprising environmentally conscious energy systems. The purpose of this report set forth is to investigate in how biogas production can be integrated into a possible energy system of this ecocity. This report groups the proposed energy system into three parts: the collection of organic waste from the city residents, the production of biogas at a central facility and the transformation of the biogas into an applicable form of energy. Technologies that are investigated and analyzed according to set learning objectives of this report, are the Envac vacuum system and the foodwaste- disposer for the collection phase, the anaerobic digestion process for the production phase, in addition to the Combined-Heat-and-Power plant and the refinery plant for the transformation phase. In order to fully elaborate the energy system of this report, both a conceptual model as well as a simulative model have been created.   The final suggestion brought forward for the composing of the appropriate energy system for the Sino-Swedish Eco-City includes the Envac vacuum system in the collection phase, an anaerobic digestion process in the production phase and a Combined-Heat-and-Power plant for the transformation phase. However, the discussion regarding the validity of the results has highlighted the possibility of expanding the biogas system to encompass a larger area than only the Eco-City. Enabling users from the surrounding areas to connect to the energy system may create incentives for the use of a refinery plant instead of a CHP plant. The final results of the model showed a potential capacity for biogas production of 600 000 m3 which in turn could be transformed into either 380 000 m3 or 1 280 MWh electricity and 1 900 MWh heat.