Biogas Upgrading Technology
Full-system solutions utilizing three leading biogas upgrading technologies
Greenlane’s biogas upgrading solutions are marketed and sold under the Greenlane Biogas™ brand. Biogas upgrading systems cleanse the impurities in biogas and separate the carbon dioxide from the biomethane to create a clean, high-purity low-carbon fuel: biomethane / renewable natural gas (RNG).
Greenlane is the only biogas upgrading company to offer multiple core technologies: water wash, pressure swing adsorption (PSA), and membrane separation.
Biogas Upgrading Solutions by Project Type
Greenlane manages the entire project life cycle from design and procurement through to on-site installation, commissioning, and aftercare. Post-installation, Greenlane provides aftercare service including 24/7 technical support and remote monitoring, as well as maintenance and spare parts.
Best for larger biogas upgrading projects demanding high biomethane recovery and robust, reliable operation
Greenlane leads the field in water-wash (or water-scrubbing) technology, the most deployed biogas upgrading technology in the world. Water-wash systems use counter-flow water to scrub away impurities, without the need for chemicals or heat.
The Greenlane water wash process is simple and requires no upstream treatment. The raw untreated biogas is compressed, and then simply flows upwards through a cascade of water. The carbon dioxide, hydrogen sulphide, volatile organic compounds, and siloxanes dissolve into the water while the methane does not, separating the two. The methane is then dehydrated providing pure, dry RNG. The water is cleaned of the impurities by flowing air through it and reused in a closed loop.
The Greenlane Biogas™ product line for high efficiency water-wash systems comprises five models designed to meet a wide range of flow-rate requirements. All the models are of a standard modular design with a compact footprint, able to process different raw biogas flow. Where larger capacity is required, we provide multiple systems in parallel.
PRESSURE SWING ADSORPTION
Best for complex feedstock
Pressure Swing Adsorption (PSA) is an effective method of separating specific gases from a complex mixture of gases, like those generated in landfills. The Greenlane 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 Renewable Natural Gas / Biomethane. 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.
While PSA is the only technology that removes nitrogen, high nitrogen levels can reduce methane recovery rates. Because of this, the best option in high Nitrogen applications, or those with especially tough gas grid specification is often to pair a PSA with another biogas upgrading technology such as water wash - an excellent combination that is only available through Greenlane.
Best for smaller biogas upgrading projects and reduced upfront expenditure
Membrane separation technology uses three stage high efficiency tubular porous membranes to separate the carbon dioxide from the methane in a process called permeation. As the biogas passes through the tubes, the smaller carbon dioxide molecules pass through the walls of the highly selective permeable membranes while the larger biomethane molecules do not.
Membrane separation is often best suited for small to medium sized biogas upgrading projects where initial capital expenditure is considered more important than long-term life cycle costs.
However with a modular design and container enclosed packages, no gas flow is too low or too high for the Greenlane membrane biogas upgrading plants. With a three stage process, and the ability to remove both CO2 & O2 together, these systems offer reliable performance and high biomethane recovery, which is typically over 99%.