- Biogas enters
- Carbon dioxide and other polar molecules have a higher solubility in water than methane. Therefore water can be used to remove contaminants from biogas.
- If the contaminants are removed or ‘scrubbed’ at high pressure (~130 psig), the water can be continuously regenerated of ‘stripped’ in a separate low pressure vessel (~3 psig).
- High quality biogas (renewable natural gas) exits.