Abstract

Urban waste generation and disposal remains a major global issue. As the world’s population grows past the 7 billion mark and more people move to urban areas, the amount of waste generated will grow accordingly. The most promising solutions to this problem are waste to energy technologies in the form of biological treatment of organics through anaerobic digestion and thermal decomposition via plasma arc gasification. These two technologies can be used in the urban environment separately or complimentarily to reduce the volume of the waste being processed while also generating heat and power (CHP) and reducing transportation costs and greenhouse gas emissions. In this research, the feasibility of heating a small-scale anaerobic digester using an air source heat pump and solar heat gains from a greenhouse located on the roof of an urban building in Montreal, Canada, is investigated during the coldest month of the year. Small-scale implementation of anaerobic digestion systems for backup and emergency power is also investigated for both the urban and rural environments as a solution for increased grid blackouts caused by more frequent and more severe storms. Derating curves are determined for generators operating under extreme unbalanced load conditions in both the urban and rural environments. The benefits and disadvantages of induction and synchronous generator systems are presented for small to large-scale systems (20kW to 2000kW).