Modeling of a District Heating System Utilizing Waste Heat Recovered from the Exhaust Gas of an Existing Solid Waste-Based LFG Engine-Driven Power Plant

Abstract

This study presents a comprehensive energy and exergy analysis using actual operational data from an existing landfill gas (LFG) engine-driven power plant that generates electricity by combusting LFG collected from the combined solid waste disposal areas of Bayburt and Gumushane, two neighboring cities in the Eastern Black Sea region of Türkiye. The energy and exergy efficiencies of the power plant were determined to be 42.71% and 59.29%, respectively. A district heating system model was developed to utilize the energy of combustion gases at 430 °C from the LFG engine-driven power plant. The district heating model, designed to serve 529 residential units, achieved energy and exergy efficiencies of 42.51% and 38.17%, respectively. Integration of the district heating model with the LFG engine-driven power plant increased the overall system apos;s energy and exergy efficiencies to 62.32% and 64.76%, respectively. SPECO-based thermoeconomic analysis demonstrated that the investment in the district heating model could be recovered within 2.65 years. Furthermore, the findings show that implementing a well-designed infrastructure project in conjunction with an efficient waste-heat-based district heating system can prevent the annual emission of 1,085.53 tons of CO2 from residences currently heated with natural gas. The results indicate that electricity generation from LFG at solid waste disposal facilities, combined with district heating applications utilizing heat recovery from plant waste gases, constitutes a highly effective, sustainable, and environmentally friendly waste-to-energy solution for the clean energy transition era.