Canada-based Greenlane Biogas North America Ltd., a subsidiary of Greenlane Renewables Inc., has secured a new US$6.3-million biogas upgrading contract with a customer in California, whose name is being withheld at this time for confidentiality reasons.

Engineering work will begin immediately on the California-based landfill project. Order fulfilment will begin immediately upon completion of permitting and approval of submittals by the customer, expected by early- to mid-2020, with delivery expected to occur within approximately six months of commencement.

The facility is expected to process 1,600 standard cubic feet per minute of landfill gas to produce ~97% pure biomethane, or approximately 380,000 gigajoules (GJ) (or 360,000 million British Thermal Units (MMBTU)) annually, of clean Renewable Natural Gas RNG) for direct injection into the local gas distribution network owned and operated by SoCalGas, the largest natural gas utility in the United States.

In addition, the residual off-gas, a byproduct of the biogas upgrading process, will be blended with natural gas to generate power for on-site facilities and processes.

This project is designed to achieve stringent SoCalGas Rule 30 quality specifications and may be the first of its kind to work in conjunction with power generation to target 100% methane recovery. To date, there are no projects upgrading landfill gas into RNG for injection into SoCalGas’ network.

Greenlane’s pressure swing adsorption (PSA) technology solution was selected for this project based on several criteria, including reliability, overall life-cycle cost, and ability to work seamlessly with other processes.

Pressure Swing Adsorption (PSA) is an effective method of separating specific gases from a complex mixture of gases, like those generated in landfills. The PSA process involves several steps to purify the biogas and separate the methane from the carbon dioxide.

Hydrogen sulfide is removed first, and then the biogas is chilled and dehydrated. An adsorbent media then traps the carbon dioxide, nitrogen, oxygen, and any remaining moisture, allowing the methane to pass through as clean and dry RNG. The media is regenerated and reused by releasing the pressure and putting it under a vacuum which causes the media to release the trapped contaminants.

Biogas upgrading is a process through which trace impurities in the biogas stream are removed and carbon dioxide is separated from methane (CH₄₎ to produce pipeline-spec biomethane suitable for injection into the natural gas grid and for direct use as vehicle fuel.

Greenlane is the only biogas upgrading company offering the three main biogas upgrading technologies: water wash, pressure swing adsorption, and membrane separation. The company has more than 30 years industry experience, and has supplied more than 100 biogas upgrading units into 18 countries.