New Grid Injection Agricultural Residue Modular Garage / Tunnel Dry Batch Plug Flow Automated Feeding Biomethane Plant

This state-of-the-art biomethane facility utilizes a modular array of gas-tight reinforced concrete garage/tunnel digesters operating in a staggered, high-solids dry anaerobic digestion (batch plug-flow) configuration. High-lignocellulose agricultural residues (2040% total solids) are introduced via automated crane and push-floor feeding systems into discrete fermenter tunnels. Within each module, digestion follows a quasi-plug-flow dynamic: instead of internal mechanical agitation, flow and active microbial inoculation are sustained via a heavy-duty, heated percolate spraying/recirculation loop that trickles digested liquor uniformly through the porous, stationary biomass bed to facilitate enzymatic hydrolysis and mass transfer without mechanical fouling.

The plant operates under a strictly regulated mesophilic or thermophilic thermal regime (38C55C), sustained by embedded hydronic radiant floor/wall heating conduits and in-line percolate heat exchangers. Raw biogas collected across the staggered batch modules is stabilized into a continuous, high-volume flow and directed to an energy recovery and upgrading train. This system integrates condensing gas boilers/micro-CHP units for process parasitical heat alongside membrane gas permeation upgrading, producing grid-compliant pipeline biomethane (>97% $\text{CH}_4$) pressurized for direct natural gas grid injection.