Bright Biomethane Supplies Biogas Upgrading System to Largest WWTP of The Netherlands

Bright Biomethane supplies the biogas upgrading system with membrane separation technology to the largest waste water treatment plant (WWTP) of the Netherlands: WWTP Harnaschpolder of the Delfland Water Authority. The produced renewable gas is supplied to the transport sector. Construction is progressing extremely well and the first renewable gas is expected to be supplied to the grid in August this year.

Operational management and maintenance of the Harnaschpolder waste water treatment plant in Den Hoorn is carried out by Delfluent Services B.V. on behalf of Delfland Water Authority. At this WWTP, approximately 6.5 million Nm3 (cubic meters) of biogas per year is produced from sludge digestion.

The biogas produced consists of around 60% methane, and is not immediately suitable for gas grid injection. Bright Biomethane’s biogas upgrading system ensures that the biogas is upgraded to renewable gas, also known as biomethane, consisting of 89% methane. Around 4.5 million Nm3 of renewable low-calorific gas (L-gas) with natural gas quality will be injected annually in the gas network of network manager Westland Infra, and supplied to the transport sector, accounting for around 30 million km of road transport per year. In the future, the biogas upgrading installation can easily be made suitable for the production of high-calorific gas (H-gas).


The Delfland Water Authority is one of the 21 water authorities in the Netherlands, and wants to create a working environment that is as sustainable and circulair as possible. Delfland has the ambition to be energy neutral by 2025. In addition, the water board also wants to supply green energy to third parties. The production of renewable gas is therefore another important step in this energy transition. Bright Biomethane already realized a renewable gas installation for Delfland before: at WWTP De Groote Lucht in Vlaardingen. This way, Bright’s biomethane systems make a important contribution to the sustainability of the transport sector and the energy transition in the Netherlands.


Bright Biomethane uses proven 3-stage membrane separation technology to separate the present carbon dioxide (CO2) from the methane (CH4). This 3-step technology, which circulates the permeate of the different stages, ensures that the highest possible efficiency (>99.5%) is achieved, and the lowest possible methane slip (<0.5%). This is a significantly lower methane slip compared to other separation technologies for the upgrading of biogas to biomethane.