Inland Empire Utilities Agency (IEUA), a municipal water district based in Chino, CA is currently executing a cogeneration power project, titled Renewable Energy Efficiency Project (REEP) at the Regional Plant No.5 (RP-5), which showcases a variety of innovative technologies for the power production. The project involved many innovative technologies, most of which are still in the research and or piloting stages. Designing a gas purification system for fuel cells, which have been commercialized only a few year ago, required a lot of ground work and research. After a thorough technical analysis with reliability as the primary criterion, Parsons recommended gas refrigeration as the best technology for gas purification for this project. A life cycle cost analysis of the above alternatives was performed to choose the best system configuration and a cost benefit analysis was carried out to project savings on O&M costs on IC engines due to gas cleaning. After thorough analysis, final recommendations were made to the Agency with a cost- effective and reliable fuel gas purification system to comply with the stringent SCAQMD permit requirements.
The REEP includes cogeneration with Internal Combustion (IC) engines designed to operate on a mixture of biosolids digester gas and manure digester gas. . The IC engines produce power for use at the RP-5 Water Reclamation Facility (RP-5 WRF) and other facilities including the new headquarters buildings. Waste heat is recovered from engine jackets and exhausts and utilized in the existing absorption chillers supporting the headquarters’ heating, ventilation and air conditioning (HVAC) system. The Agency is also maximizing the digester gas production through the addition of food waste (restaurant and dairy waste) to biosolids and manure digesters. The innovative technologies under this project include Organic Rankine Bottoming Cycle (ORC), Thermal Energy Storage (TES), Stirling engine, and fuel cell system in the future.
One of the primary challenges of this project was to evaluate, select and design a cost-effective and reliable gas purification system to serve both IC engines and fuel cells (for future installation) for a mixture of fuel gases from biosolids and manure digestion.