From Biogas to Biomethane — Why Upgrading Matters
Biogas is a renewable energy source created from organic waste through anaerobic digestion. But in its raw form, biogas contains impurities like carbon dioxide (CO₂), hydrogen sulfide (H₂S), and moisture.
For it to become high-value biomethane — suitable for grid injection, transport, or use as compressed natural gas (CNG) — these impurities need to be removed.
One of the most proven, reliable, and widely used methods is Water Scrubbing. To understand why it’s so widely used, let’s look at how water scrubbing works.
How Water Scrubbing Works
Water scrubbing takes advantage of a simple scientific fact: CO₂ and H₂S are more soluble in water than methane (CH₄).
Here’s the process in brief:
Compression: Raw biogas is compressed to increase the solubility of the impurities.
- Absorption: Operators feed the compressed gas into a water-filled column. CO₂ and H₂S dissolve into the water, leaving methane behind.
- Water Regeneration or Replacement: The water — now containing dissolved CO₂/H₂S — is either regenerated by releasing the gases or replaced with fresh water.
This process yields high-purity biomethane — typically 96–98% CH₄. In addition to being chemical-free, water scrubbing also offers operational reliability.
Advantages of Water Scrubbing
- Proven Technology: Decades of use in biogas plants worldwide.
- Chemical-Free: No additional reagents or solvents are needed.
- Scalable: Works well for medium to large plants.
- Dual Removal: Eliminates CO₂ and H₂S in one step.
Considerations and Limitations
- Water Demand: Requires a steady water supply or a recirculation system.
- Energy Use: Compressing the gas and pumping water consumes electricity.
Size: Systems can be relatively large compared to newer technologies like membranes.
When Water Scrubbing Makes Sense
Water scrubbing is often the best choice for:
- Plants with steady, high-volume feedstock supply.
- Locations where water is readily available.
- Operators looking for long-term reliability with minimal chemical handling.
However, upgrading is just the first step — transporting biomethane efficiently is equally important.
From Plant to Market — Where Gaznet Comes In
Once your biogas is upgraded to biomethane, the next challenge is getting it to where it’s needed — whether that’s a grid injection point, industrial user, or vehicle fueling station.
This is where Gaznet’s ADR-approved Type IV composite MEGC containers come into play:
- Lightweight, robust, and long-lasting for lower lifecycle costs.
- Perfect for transporting biomethane at high pressures (CNG form) safely across Europe.
- Available with tailored configurations to fit your operational needs.
In short: Water scrubbing produces the biomethane. Gaznet delivers it — safely, efficiently, and anywhere it’s needed.
If you’re planning a biogas upgrading project or want to explore biomethane transport options, contact Gaznet’s team for a tailored solution.