Energetic valorization of biogas. A comparison between centralized and decentralized approach

In the present manuscript, the energy efficiency and economic feasibility of different digestion configurations were evaluated by considering a double turbocharged engine, Jenbacher type JGS 320 GS-BL. Scenarios considered a single farm producing the biogas needed to run the engine (Scenario 1). The second scenario assumed a centralized system treating manure from the surrounding farms (Scenario 2). The third scenario considered partial decentralization with farms treating locally produced wastes, and biogas being transported and valorized in a centralized engine (Scenario 3). Centralized valorization showed the best results. However, this scheme is inappropriate due to the size of the farm needed to support this configuration. The transport of wastes to a centralized treatment unit showed similar efficiency values but the economic feasibility was adversely affected. The worst performance was found for the decentralized configuration with efficiency in the range of 39-43%, much lower values than those obtained from previous cases (58%) with null economic feasibility due to the high costs associated with the transport of biogas either by truck or through a piping system.