Biogas consists of approximately 55% methane (CH4) and 45% carbon dioxide (CO2). In addition, the biogas contains H2S, NH3 and often volatile organic hydrocarbons (VOCs), such as siloxanes and terpenes. The biogas is also saturated with moisture. In order to be able to process biogas into electricity, heat or green gas, it must be cleaned and possibly upgraded to natural gas quality.
Biogas Plus designs, supplies and installs green gas installations. This extends from the connection to the digester up to and including the connection to the CHP or natural gas network. This can be integrated in a turn-key project with the biogas production, but also separately at an existing biogas installation.
The operation of a gas upgrading plant follows the following three steps:
- Biogas cleaning (removal of moisture, H2S and often also volatile organic hydrocarbons)
- Biogas upgrading (removal of CO2)
- Quality control of the green gas and the addition of fragrance
Biogas cleaning
The basis for reliable gas upgrading is thorough biogas cleaning. The legislation sets very strict requirements for pollutants in green gas, and the membranes are also vulnerable to pollutants. The biogas is therefore the first to pass through a washing tower, where all water-soluble pollutants, as well as dust, etc. are washed out. Subsequently, the remaining H2S and VOCs are thoroughly removed with two activated carbon filters.
Gas upgrading
The clean biogas is upgraded to natural gas quality with patented 3-stage membrane technology. The third stage provides for recovery of the methane lost in the work-up, so that a methane loss of only 0.5% is achievable. The green gas produced meets all the requirements of current legislation and regulations.
A reliable screw compressor brings the biogas to the pressure required for the membranes, and also ensures sufficient pressure for the injection of the green gas into the regional natural gas network.
Injection
When injection the green gas into the gas grid, the Bio2Net fulfills the role of gatekeeper, guarding access to the natural gas network. The Bio2Net guarantees that only gas that meets all quality requirements enters the natural gas network. Gas that is not 100% compliant is returned to the gas producer.
To this end, the Bio2Net is equipped with an accurate gas chromatograph and several additional analyzers, which check the green gas at all required points. The Bio2Net also ensures the required odorization of the gas supplied.
Result: spotlessly clean gas, which guarantees a long life and good performance.
