Operation principle
Water-wash (or water-scrubbing) is the technology for which Greenlane is world famous. With 30 years’ experience and 100 sites operational worldwide, we are ‘pioneers’ in this space.
Water-wash, which is a safe, reliable and proven technology is the most environmentally friendly, using no chemicals or heat. In addition it is a highly efficient upgrading process for medium, large and ultra large projects and where planning permission for the water towers is not an issue. It is ideal when the end use is grid injection.
From the gases produced in the anaerobic digester (AD), landfill site or water treatment plant, carbon dioxide, (CO2) and hydrogen sulphide, (H2S), are separated from the methane (CH4) under pressure and absorbed into water, the methane is not absorbed and passes into the drier. After upgrading the methane content can be as high as 98%.
At the heart of the facility a simple, robust, reliable compressor to ensure a high availability of biogas which in turn contributes to greater efficiency and therefore lower operating costs.

The advantages
- No heat requirement
- No chemicals
- Less than 1% methane slip
- H2S tolerance with no separate pre-wash required – even for high levels
- New, improved layout and access to key components
- Most reliable compression technology
- Modular design gives scalable capacity
- Can work in conjunction with other upgrading systems