Analysis of biogas and other gas mixturesBiogas consists principally of methane and carbon dioxide but can also contain small amounts of a wide range of other compounds. Some of them don’t contribute to the energy content, and may be corrosive, poisonous or be responsive for releasing bad smells in the neighbourhood or during the process. Knowledge about biogas content is thus valuable.
SP provides analyses of biogas and other gas mixtures, as example natural gas, process gases… via sampling in a gas-tight bag or directly from gas tubes. Special gas-tight bags can be provided by us. If needed, we can also assist with sampling directly at the facility. With access to many different instruments of analyses, we can offer gas analyses, all after requirement. Quality assurance of our analyses is obtained by mean of certified gas mixtures in tubes.
Example of analyses we can offer:
- Methane, CH4: 1000 ppm
- Carbon dioxide, CO2: 1000 ppm
- Carbon monoxide, CO: 1000 ppm
- Nitrogen, N2: 1000 ppm
- Oxygen, O2: 1000 ppm
- Hydrogen, H2: 200 ppm
- Hydrogen sulfide, H2S: 2000 ppm
In cases where more compounds or/and lower detection limits are required, we can also offer the following analyses:
- Low molecular hydrocarbons (C2-C5, ethane-pentane, saturated and unsaturated: 0.5 ppm
- Carbon dioxide, CO2: 10 ppm
- Carbon monoxide, CO: 5 ppm
- Hydrogen sulfide, H2S: 1 ppm or lower
- Water: 2000 ppm or lower
Analyses of particles content
We can also take samples through filters and search for solid particles by scanning-electron microscopy (SEM). The particles content can also be identified.
The analyses are performed by use, as example, of a gas chromatograph (GC) equipped with a TCD (Thermal conductivity detector), FID (Flame ionisation detector) and MS (Mass spectrometry). Compounds present at low concentrations in the gas can be enriched onto an adsorbent before GC/MS analysis. For some compounds electrochemical cells are used.