Innovative Landfill Gas Treatment System in Latvia: Evaluation of a Full-Scale Purification Prototype

Landfill gas (LFG), a by-product of anaerobic waste decomposition, represents both an environmental liability and a renewable energy resource. This study presents the development and performance evaluation of a prototype LFG purification system installed at a major landfill in the Baltic region – Landfill A. The system integrates desulphurisation, cooling and drying, siloxane separation, and activated carbon filtration to ensure high-quality fuel gas for energy recovery. Gas quality was monitored at five treatment points to determine purification efficiency. The results demonstrated stable methane concentrations (55.8–56.6 %) throughout all stages, confirming minimal energy loss. Hydrogen sulfide levels decreased by more than 97 %, from 1930 mg/m³ to below 40 mg/m³, while ammonia was reduced by >99 %. Siloxane compounds, a major cause of engine damage, were almost completely removed (>99.8 % reduction). Volatile organic compounds decreased by ~89 % overall, with final concentrations of ~65 mg/m³. The prototype achieved its design flow of 1500 m³/h, supplying three CHP units with 2.8 MW of instantaneous electrical output. These findings confirm the system’s effectiveness, modularity, and applicability for broader deployment in EU waste-to-energy facilities. The technology enables cost-efficient energy recovery, compliance with EU environmental standards, and the potential future upgrading of LFG to biomethane for injection into natural gas grids or use as transport fuel.