Operational Organic Fertilizer Production Food Waste Modular Garage / Tunnel Dry Batch Plug Flow Automated Feeding Bio-CNG Plant

This high-solids anaerobic digestion facility processes source-segregated food waste using a modular array of reinforced, gastight garage/tunnel batch digesters configured to operate in a staggered, pseudo-continuous plug-flow regime. Solid substrates (2535% total solids) are charged via automated push-floor hoppers and heavy-duty, low-speed positive-displacement feed augers, eliminating hydraulic dilution. Inside the sealed tunnels, mechanical mixing is bypassed in favor of continuous percolate recirculation: heated, biologically active liquid digestate is sprayed across the biomass bed to ensure uniform enzymatic dispersion, microbial inoculation, and active mass transfer without bed stratification.

The system operates under a controlled mesophilic thermal regime (3740C), regulated by in-floor hydronic heating loops and percolate heat exchangers. Biogas generated during batch digestion is evacuated to a double-membrane gasholder, desulfurized via biological trickling and activated carbon, and directed to a membrane-separation upgrading unit to produce biomethane (>97% $\text{CH}_4$) compressed to 200250 bar as vehicle-grade Bio-CNG. Tail-gas heat and parasitic thermal loads are integrated through a waste-heat recovery loop. Post-digestion, stabilized solid digestate is dewatered and aerobically cured into high-grade organic fertilizer, closing the nutrient loop.