Landfill gas recovery

What is landfill gas?

Landfill Gas is a colorless, flammable gas produced by the action of methane-creating bacteria on biodegradable materials in an anaerobic (air-less) environment. This type of environment occurs naturally in a covered landfill. The typical landfill gas composition is: 50%-70% Methane, 30%-40% Carbon Dioxide, 5%-10% Hydrogen, 1%-2% Nitrogen, traces of Water vapor, and H2S.

Uses for landfill gas include…

Landfill gas can be used in place of natural gas or propane for motor fuel, home heating, or fuel for a microturbine power generating stations or fuel cells once properly treated. It gives the user the options to flare the gas, or release it to the atmosphere.

Compressor application…

 A Landfill Gas Recovery system consists of extraction wells or horizontal trenches carefully placed throughout the landfill site. Landfill gas is collected from the extraction wells or horizontal trenches dug into the landfill site. As the gas is recovered, it is pulled through a liquid knockout trap using a reciprocating gas compressor and distributed to a main collection header where it is treated for use downstream or flared.

A reciprocating gas compressor the best option…

Corken’s Reciprocating Compressors, primarily our THG horizontal series compressors, along with our pre-engineered mountings are used for collecting the landfill gas from the gas connection of the landfill and increasing the pressure of the gas to a usable amount based on the customer’s needs. Rotary vane and lobe style compressors can be used on low differential pressure applications. Most users need discharge pressures range from 50 to 75 psig when used for microturbines to 4,000 psig in motor fuel applications. Vane and lobe style units cannot produce the higher discharge pressures needed by most users since the gas is collected at very low pressure. The gas will have to be scrubbed or filtered before use, especially if there is H2S present.

Materials of construction include…

We recommend our standard ductile iron construction with PTFE elastomers and iron-lead gaskets. A D-Style (double packed) Oil-free Compressor is recommended; however, a T-Style triple packed oil-free reciprocating compressor is recommended when there is H2S in the gas mix. MC1002 corrosion and wear-resistant coating may be needed if there is corrosive gas in the mixture. Individual users may have specific requirements indigenous to their application.