Liquefying biogenic CO₂ from biogas improves profitability in several ways: it recovers lost methane to boost output, lowers the carbon intensity of your bio-LNG (increasing certificate value), creates a new revenue stream from CO₂ sales, and positions you for future e-fuel markets. Whether CO₂ liquefaction makes financial sense depends on your bio-LNG market, proximity to CO₂ buyers, and local regulations. The sections below explain how capturing and liquefying CO₂ can strengthen your business case.
Five ways CO₂ liquefaction improves profitability:
- Lower carbon intensity – Improves bio-LNG certificate value in CI-sensitive markets
- Recover lost methane – Capture residual methane from the CO₂ stream to boost bio-LNG output
- New revenue stream – Turn a waste product into saleable liquid CO₂
- Local offtake opportunities – Serve nearby industries (food & beverage, greenhouses, cold storage)
- Future e-fuels market – Position for growing demand from synthetic fuel producers
1. Increase the value of bio-LNG by improving carbon intensity
The first major benefit of CO₂ liquefaction is that it helps lower the carbon intensity (CI) of your bio-LNG.
Under the Renewable Energy Directive (RED), captured and used biogenic CO₂ qualifies as carbon capture and utilisation (CCU). That lower CI score directly increases the market value of your fuel through higher-value sustainability certificates.
Market dependency
This CI benefit only translates into financial value if your bio-LNG is sold in markets where carbon intensity is rewarded, such as Germany. In these markets, and when a buyer actually takes up your liquefied CO₂, the CO₂ liquefaction investment can pay for itself quickly. In fact, it can be a key lever to make your entire production setup more profitable.
If your bio-LNG doesn’t end up in a CI-sensitive market, the direct revenue from selling CO₂ itself becomes the main driver. And that’s still viable, as long as you can sell it locally.
2. Recover lost methane and boost your output
No gas upgrading system is perfect. Some methane always slips into the CO₂ stream during separation. By liquefying the CO₂, you can exploit the different boiling points of methane and CO₂ to recover that residual methane, feed it back into the process, and turn it into more bio-LNG.
Your output goes up, your emissions go down, and your system works smarter. This methane recovery alone can contribute significantly to the business case for CO₂ liquefaction.
3. Turn a byproduct into a revenue stream
CO₂ makes up a large part of your raw biogas, typically 35 to 45%. By capturing and liquefying it, you’re turning a waste stream into a saleable product.
While the revenues from CO₂ won’t pay for your entire biogas upgrading system, they can often cover the cost of the liquefaction unit itself within most typical payback periods. It’s a relatively small investment with a good chance of earning itself back, assuming you have the right offtaker.
Read more about the integration of CO2-liquefaction in a bio-LNG production plant here.
4. Local offtake is critical
Liquefied CO₂ is not something you want to move across the continent. Transport costs are high, and unless you’re close to a buyer, say within 100 kilometres, your margins will quickly evaporate. That’s why CO₂ trading is so location-sensitive.
If any of the following industries that use CO₂ are operating nearby, you’ve got a solid basis to make CO₂ recovery worthwhile:
- Breweries and soft drink producers
- Cold storage warehouses
- Food processing and packaging companies
- Greenhouses (horticulture)
- Cement and concrete plants
5. E-fuels: early potential, future upside
E-fuel production (fuels created through the synthesis of green hydrogen and biogenic CO₂) is expected to become a major CO₂ market in the future. Right now, it’s still emerging, mainly because the viability of green hydrogen production depends on very low electricity prices.
But the direction is clear: when the e-fuel market scales up, the demand for clean, biogenic CO₂ will rise with it. Biogenic CO₂ is particularly attractive for e-fuels because it’s renewable and carries a low carbon intensity, making the resulting fuel more sustainable.
If you’re near a hydrogen hub or pilot plant, your liquefied CO₂ could become a valuable feedstock in the coming years.
Is CO₂ liquefaction right for your bio-LNG project?
CO₂ liquefaction can significantly improve the profitability of your bio-LNG project, but the business case depends on three key factors: whether your bio-LNG is sold in a CI-sensitive market, whether you have local offtake opportunities for liquid CO₂, and whether you want to position for future e-fuels demand.
The investment in CO₂ liquefaction is relatively modest compared to the core bio-LNG plant, and in the right conditions it can pay for itself through a combination of improved CI value, direct CO₂ sales, and recovered methane.
For Nordsol’s bio-LNG installations, CO₂ capture and liquefaction is a highly recommended option that is fully integrated with bio-LNG production to maximise your revenue potential. Our modular approach allows you to add CO₂ liquefaction from day one or retrofit it later as market conditions evolve.
Contact our team to discuss whether CO₂ liquefaction makes sense for your project, or explore our other FAQs.
