Landfill Biogas Extraction and Collection Stations
Well-by-well adjustment to maximise methane content and energy recovery
At managed landfills and remediation sites, biogas produced by the anaerobic decomposition of municipal solid waste is an energy resource that is often underused or flared without energy recovery. This gas, consisting mainly of methane at concentrations ranging from 40% to 60% and CO2, is extracted from collection wells through a network of pipes under vacuum connected to a central blower. Efficient management of this network requires individually controlling the suction applied at each well to balance flows and maintain a sufficiently high methane content in the mixed gas for use in high-efficiency cogeneration plants. Without this control, wells with high permeability tend to overpower slower wells, lowering the average gas quality and reducing the site’s overall energy output.
LAI Srl has developed a system of stations for collecting and controlling landfill biogas, designed to be installed directly near each well or group of wells with similar production characteristics. Each station allows the vacuum applied to each well to be adjusted using a manual control valve, the flow rate and methane content of the extracted gas to be monitored using integrated meters, and wells producing gas with a methane content unsuitable for energy use to be managed selectively
The ability to operate well by well maximizes the volume of good-quality gas sent to the cogeneration plant, while sending only low-quality, unrecoverable gas to the safety flare.
For landfills in the late stages of operation or post-closure, where biogas production is gradually declining in both flow rate and methane content as fermentable organic matter is depleted, LAI offers dual-header substations. In this configuration, one header collects the high-quality gas and sends it to the cogeneration unit or upgrading plant, while the second directs low-quality gas straight to the flare.
This system extends the site's energy recovery period, even when gas quality is variable, extracting value from wells that would otherwise be excluded from the collection network. All LAI substations are made of stainless steel with fittings certified for flammable gases, and can be integrated into the plant's centralized supervisory system for remote monitoring and control of all site gas collection parameters.
