Bio-LNG is liquefied biomethane — a renewable substitute for fossil LNG that ships can burn in the same tanks and engines without modification. It matters right now because it’s one of the few fuels that counts toward FuelEU Maritime compliance today.
This guide covers how it’s made, how it compares to fossil LNG on emissions, and where it stands under current shipping regulation.
Key Takeaways:
- Production: Bio-LNG comes from biomethane made via anaerobic digestion of agricultural and organic waste, or gasification of woody biomass.
- Emissions: Bio-LNG cuts well-to-wake GHG emissions by up to 80% versus marine diesel, and manure-derived bio-LNG can reach net-negative emissions of up to -190%.
- Regulation: Bio-LNG already counts as a Renewable and Low-carbon Fuel under FuelEU Maritime, in force since January 2025.
What Is Bio-LNG?
Bio-LNG, or liquefied biomethane, is a renewable fuel alternative gaining ground in maritime shipping. It’s chemically almost identical to fossil LNG, which is what lets it drop into existing LNG infrastructure.
Bio-LNG and biomethane are the same molecule in two different states. Biomethane is the purified, gaseous form produced by anaerobic digestion or gasification. Bio-LNG is that same gas cooled to about -162°C and liquefied for storage and transport, the same process used for fossil LNG.
The same fuel goes by different names depending on the region. In North America it’s usually called Renewable Natural Gas (RNG). In Europe, the industry term is Synthetic Natural Gas (SNG).
SNG is technically a broader category that also covers fossil-derived synthetic methane, so “bio-SNG” is the more precise term for the renewable version specifically.
So what is bio-LNG at its core? It’s methane derived from organic sources — agricultural waste, food waste, manure, or other biomass feedstocks. It’s liquefied for storage and transport the same way fossil LNG is.
Vessels powered by dual-fuel engines, capable of running on both LNG and bio-LNG, are already in service. Our guide on dual-fuel engines in ships covers how those engines work.
How Is Bio-LNG Produced?
Bio-LNG production turns waste streams into a usable marine fuel through one of two main pathways.
The dominant method is anaerobic digestion. Organic matter — agricultural residue, manure, food waste — breaks down without oxygen, producing biomethane that’s then liquefied into bio-LNG.
Gasification is the second pathway, converting woody or cellulosic waste like forestry and sawmill residue into bio-LNG. It’s less mature commercially than anaerobic digestion but is developing as a future supply source.
Bio-LNG vs. Traditional LNG
Bio-LNG and fossil LNG are chemically almost identical, but their origins differ. Bio-LNG comes from renewable waste streams. Traditional LNG is extracted from underground gas fields, typically via fracking or as a byproduct of crude oil production.
That different origin is what drives the emissions gap between them, covered in detail below.
For more on how LNG compares to other gas fuels, see our comparison of LNG vs. LPG.
Environmental Benefits and Emission Reductions
Bio-LNG’s environmental case rests on lifecycle emissions, not just tailpipe output. On a full well-to-wake basis, bio-LNG used as marine fuel can cut greenhouse gas emissions substantially. SEA-LNG puts the figure at up to 80% compared with marine diesel.
That 80% figure is a total-GHG reduction, not a claim about tailpipe methane specifically — engine methane slip is a separate issue, covered below.
Bio-LNG made from manure through anaerobic digestion can go further still. The process captures methane that manure would otherwise release into the atmosphere anyway. That can push the fuel’s net lifecycle footprint negative — as much as -190% versus diesel, according to SEA-LNG’s analysis.
These figures come from well-to-wake analysis. It accounts for the fuel’s entire lifecycle — production, transport, and combustion — rather than just emissions at the point of use.
Availability and Market Potential
Biomethane production, the feedstock for bio-LNG, currently runs at roughly 30 million tonnes a year. Per SEA-LNG, that’s enough to cover about 10% of shipping’s total energy demand.
Growth projections put biomethane production at up to 20 times current levels by 2050. Policy is the driver, including the EU’s RED III directive and US EPA Renewable Fuel Standards.
On its own, bio-LNG could then meet up to 13% of shipping’s total fuel energy demand. Blended at 20% with conventional LNG, that figure rises to as much as 63% of global shipping demand by 2050.
Commercial Aspects of Bio-LNG
Bio-LNG is already commercially available in Europe, North America, and Asia. It’s usually sold blended with fossil LNG, which lets suppliers use existing LNG bunkering infrastructure rather than building parallel supply chains.
On price, bio-LNG typically costs two to three times more than fossil LNG. Carbon-credit value and regulatory compliance benefits (below) are what make that premium worth paying for many operators today.
The bunker delivery note usually won’t show whether a cargo is bio-LNG. Blended batches are typically tracked through mass balancing, not physical segregation. A buyer can be credited with a renewable share that wasn’t in the exact tank delivered.
What proves the content is a separate Proof of Sustainability document, usually issued under ISCC certification. It confirms the feedstock, chain of custody, and GHG savings for that delivery.
For more on the vessels that carry and use this fuel, see our guide to types and sizes of LNG carriers.
Bio-LNG and Shipping Regulation
Bio-LNG’s biggest near-term driver isn’t the fuel itself — it’s the regulation now pushing ships toward it.
FuelEU Maritime
FuelEU Maritime has applied to ships of 5,000 gross tonnage and above calling at EU ports since January 1, 2025. It sets a well-to-wake greenhouse gas intensity limit that tightens every year, from roughly 2% below the 2020 baseline in 2025 to 75% by 2050.
Bio-LNG qualifies as a Renewable and Low-carbon Fuel (RLF) under the regulation, with its emissions intensity assessed using RED-based methodology. Using it in the fuel mix directly lowers a ship’s calculated GHG intensity, helping meet the annual target.
The IMO Net-Zero Framework
At the global level, the IMO’s proposed Net-Zero Framework would set a shrinking GHG Fuel Intensity limit for ships over 5,000 GT. Fuels below 19.0 gCO2eq/MJ would count as “zero or near-zero” and qualify for financial rewards.
It isn’t in force yet. MEPC approved it in April 2025, but formal adoption was postponed, with discussions set to resume later in 2026.
If and when it’s adopted, it would enter into force roughly 16 months later. Bio-LNG’s eligibility would depend on its certified lifecycle intensity meeting that threshold. Treat this as a fuel to watch, not yet a locked-in compliance pathway.
Methane Slip and Bio-LNG
Methane slip is unburned methane escaping during combustion. Since methane traps far more heat than CO2 over the short term, even small amounts matter for a fuel’s overall climate impact.
- It’s an engine issue, not a fuel issue: methane slip depends on engine design, not on whether the methane came from a fossil or renewable source. Bio-LNG performs the same as fossil LNG in this respect.
- Modern engines have largely solved it: two-stroke diesel-cycle engines, which make up roughly 75% of the current LNG-fuelled order book, have effectively eliminated slip. Low-pressure four-stroke engines, where slip was more of an issue, have cut it by more than 85% in recent designs.
Engine efficiency is one piece of the bigger push toward sustainable shipping — fuel choice and engine technology both matter for actual emissions outcomes.
Frequently Asked Questions About Bio-LNG
What is bio-LNG?
Bio-LNG is liquefied biomethane made from renewable organic waste rather than fossil natural gas. It’s chemically almost identical to fossil LNG, so ships built for LNG can burn it without modification.
How is bio-LNG produced?
Most bio-LNG comes from anaerobic digestion of agricultural waste, manure, or food waste, which produces biomethane that’s then liquefied. A smaller share comes from gasifying woody biomass, a less mature but developing pathway.
What is the difference between bio-LNG and LNG?
Bio-LNG and fossil LNG are chemically similar, but bio-LNG is made from renewable waste streams while fossil LNG comes from underground gas fields. That different origin gives bio-LNG a much lower well-to-wake carbon footprint.
Is bio-LNG used in commercial shipping today?
Yes. Bio-LNG is commercially available in Europe, North America, and Asia, typically blended with fossil LNG and supplied through existing LNG bunkering infrastructure. It already counts as a compliant fuel under FuelEU Maritime.
Does bio-LNG increase methane slip compared to LNG?
No. Methane slip depends on engine design, not fuel source, so bio-LNG and fossil LNG perform the same in engines with the same technology. Modern two-stroke and low-pressure four-stroke engines have both cut slip substantially.
Does bio-LNG count toward FuelEU Maritime compliance?
Yes. Bio-LNG qualifies as a Renewable and Low-carbon Fuel under FuelEU Maritime, which has applied to ships over 5,000 GT calling at EU ports since January 2025, and using it lowers a ship’s calculated GHG intensity.
Is bio-LNG the same as biomethane?
Yes, in composition. Biomethane is the gaseous form produced by anaerobic digestion or gasification; bio-LNG is that same gas cooled to about -162°C and liquefied for storage and transport.
How do you verify bio-LNG content from the bunker invoice?
The bunker delivery note usually doesn’t show it, since blended cargoes are tracked through mass balancing rather than physical segregation. Verification comes from a separate Proof of Sustainability document, typically under ISCC certification, issued for that delivery.
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