Comparative Energy and Greenhouse Gas Analysis of Household Organic Waste Processing Methods: Mechanical Press-Based On-Site Processing vs. Existing Alternatives

Organic food waste landfilling is a major source of anthropogenic greenhouse gas (GHG) emissions in the United States, yet viable household-scale diversion alternatives for dense urban environments remain highly constrained. This study presents a comparative technoeconomic and environmental assessment of five food waste processing pathways: (1) conventional landfilling, (2) curbside centralized composting, (3) on-site backyard composting, (4) heat-based electric countertop appliances (thermal dehydration), and (5) a novel mechanical press-based appliance concept (AENG-OWP-15) utilizing sensorless Extended Kalman Filter (EKF) moisture control via drive motor current analysis. Baseline energy and emission data are derived from the U.S. EPA Waste Reduction Model (WARM v15), EPA eGRID 2021 grid intensity factors, and manufacturer specifications. Performance metrics for the AENG-OWP-15 are established using parameters from a foundational physics-based simulation study (Khomuilo, 2026; DOI: 10.5281/zenodo.20019104). Key findings indicate distinct trade-offs across the evaluated pathways: Thermal Dehydration Energy Floor: Commercial heat-based appliances consume 530–1,000 kWh per metric ton of waste, generating 205–386 kg CO₂e/t from grid electricity alone due to the thermodynamic limits of water evaporation. Mechanical Dewatering Efficiency: The AENG-OWP-15 mechanical press concept bypasses the latent heat phase change, operating at an estimated ~10 kWh/t (+3.9 kg CO₂e/t)—demonstrating a 50- to 100-fold energy reduction compared to thermal alternatives. Net GHG Emissions: Landfilling exhibits the worst climate impact at ~475 kg CO₂e/t due to anaerobic methane generation. Backyard composting achieves the lowest net footprint (~−165 kg CO₂e/t) through carbon sequestration but remains structurally inaccessible to multi-family urban residents. Sewage System Impact: While the liquid effluent expelled by mechanical pressing carries a high chemical oxygen demand (COD ~15,000–40,000 mg/L), its minimal volume (~1.9 L/day per household) results in a total COD mass load approximately 87% lower than that of conventional food waste disposers (sink grinders). Circular Economy Integration: The resulting high-density, sealed organic briquettes provide a stable, hygienic point-of-use nutrient recovery pathway optimized for urban collection and circular economy integration. Note: All performance figures for the AENG-OWP-15 are simulation-derived estimates; no physical prototype has been constructed. This research is associated with USPTO Provisional Patent Application No. 63/995,028.