Design and purchase of Organic Rankine Cycle equipment for Power Generation and Waste Heat Recovery Systems & Biosolids Optimization at Greenway Pollution Control Plant

completed

The main focus of this project will involve the pre-purchase of the critical components including an Organic Rankine Cycle engine power unit and heat exchanger, preliminary building modifications and process and electrical designs to generate 450 kW of electricity from waste heat recovered from the Greenway biosolids incinerator. A secondary component is a study to evaluate the potential to use waste heat from the incineration process to replace several natural gas Heating, Ventilation, and Air Conditioning (HVAC) units; the study will also evaluate the plant’s end of life hydronic heating piping system and any upgrades needed to handle additional heating loads. Biosolids Optimization Study: Currently 40% of the biosolids generated in the City of London are dewatered to 3-4 % solids at satellite plants then trucked to Greenway for incineration. This study will evaluate the feasibility of dewatering those solids to 25% solids at the satellite plants before transportation to Greenway thereby reducing the number of loads from approximately 7000 per year to 2000. Waste Heat Utilization and Optimization: The Greenway plant currently uses waste heat from the biosolids incinerator to heat most plant buildings and spaces through a hydronic heating system; however, there are several natural gas fired HVAC units onsite that can potentially be converted to utilize the hydronic system. A study will evaluate the feasibility of converting the natural gas units to the hydronic systems as well as any upgrades needed. This system is independent of the proposed Organic Rankine Cycle system. Future projects will be identified. During the design phase it was discovered that the addition of Rotating Drum Thickener (RDT) is required to accommodate tight space requirements of the Organic Rankine Cycle (ORC) with new access to penthouse required.