WIKA TECH offers a sensing technology for biogas online continuous monitoring.


Real-time control of CH4 and CO2 concentration

Gas density measurement is a cost effective method to control the CH4 and CO2 concentration of the biomethane after purification. Combined with a pressure measurement, it gives the perfect solution to monitor the process.

Typical applications of NORTHDOME for Biogas monitoring :

  • CH4 concentration in the biomethane

  • CO2 concentration in the off gases

  • Purification plant optimization and control


Gas blending

Your tasks:

Problem: Blending two different gases to a specific molar or volume ratio. NORTHDOME gas density measurement technology is the key that makes this solution possible. An ideal application is monitoring CH4 concentration in biogas before injection in the grid.

From Biogas to Biomethane:

Biogas is the by-product of anaerobic digestion of organic material found in agricultural waste, municipal wastewater treatment and landfill waste. The biogas can be used to produce heat and electricity, but also can be upgraded to biomethane.

CH4 extraction:

The cleaning and upgrading processes remove unwanted components such as CO2, H2O, H2S…, enrich its methane content and adjust its calorific value to meet natural gas standards defined by countries. Methane (CH4) concentration has to be from 96.5% to 99%.

Adding a gas density meter increases responsiveness & security:

Combining the Northdome® density meter with a WIKA pressure sensor allows to calculate the biogas mixture’s molar mass & CH4 concentration at the outlet of the updgrading process. It is used as a watchdog function thanks to its very high response time.
It does not replace the gas chromatograph but supplements the composition detection function for early warning of a problem as illustrated in the case study next page.

CO2 recovery:

After cleaning process, CO2 can be simply released into atmosphere. Nevertheless pure CO2 has a high market value for several application such as green houses or food and beverages industries as this bio-CO2 is carbone neutral.
The WIKA solution is also used to monitor the CO2 concentration and ensure quality prior gas transportation.

Product in use:


Read more

Northdome for biogas analysis (application 825.38 KB)
Brochure Northdome gas density sensor (application 900.00 KB)
Brochure Avenibridge gas monitoring unit (application 381.99 KB)