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Inland vessel running on FAME sails in ballast on wide Dutch river under clear skies

FAME for Inland Shipping: Reducing CO2 Without Modifying the Engine

Author: Jeroen Berger • Publication date:

Inland shipping is facing an accelerated sustainability challenge. Under the European Climate Law (Regulation (EU) 2021/1119) and the revised Renewable Energy Directive (RED III), EU Member States are required to ensure that by 2030, at least 14.5 percent of total energy use in transport comes from renewable sources. This target is legally binding but allows national discretion in allocating the share across different sectors. While RED III does not specify a fixed share for inland shipping, the sector can contribute through national policies or subsidy schemes. If so, inland shipping must significantly reduce CO2 emissions across the entire fuel chain (well-to-wheel), depending on the selected technology and fuel type.

For existing inland vessels, this is no easy task. Although switching to hydrogen, electric propulsion or synthetic e-fuels sounds promising, it often requires major technical modifications. These include engine replacements, fuel storage adjustments or additional safety measures. Such interventions are costly and frequently lead to prolonged downtime. For the majority of the current fleet, a full retrofit by 2030 is therefore unfeasible.

Against this backdrop, FAME (Fatty Acid Methyl Ester) offers an immediately deployable interim solution for the existing inland shipping fleet in Europe. This biodiesel variant is compatible with conventional diesel engines and can be bunkered as blends up to B20 through existing infrastructure. Provided the engine manufacturer grants approval, technical modifications are usually unnecessary. As a result, shipping companies and shipowners can reduce their CO2 emissions relatively easily, without compromising vessel availability. Within the current transition framework, FAME is regarded as a practical step toward sustainability, pending structural fleet renewal beyond 2035.

This article explores FAME’s potential role in decarbonizing inland shipping. We examine the origin and properties of this biofuel, its environmental performance, operational suitability and practical considerations. We also address the policy framework for large-scale adoption toward 2030 and 2050, and compare FAME to alternatives such as HVO, bio-LNG and GTL.

What FAME Is and How It Is Produced

FAME, or Fatty Acid Methyl Ester, is a type of biodiesel produced from vegetable oils or animal fats. During production, these fats undergo a chemical process known as transesterification, in which the fat molecules react with methanol to form methyl esters, a liquid closely resembling diesel in appearance but with a different molecular structure.

A key distinction is that FAME contains oxygen atoms in its fuel molecules. This makes the fuel biodegradable and results in lower emissions of soot, unburned hydrocarbons (HC), carbon monoxide (CO) and particulate matter (PM) during combustion. However, the presence of oxygen also increases susceptibility to aging, water absorption and microbial growth. Storage and use therefore require extra care, especially at low temperatures or during prolonged vessel lay-up.

FAME’s environmental performance strongly depends on the feedstocks used. Under the revised Renewable Energy Directive (RED III), preference is given to waste streams such as used cooking oil (UCO) or non-edible animal fats from category 1 or 2. These sources do not compete with food production and have a relatively low CO2 footprint across the fuel chain. When produced from such inputs, FAME can reduce total CO2 emissions by 80 to 90 percent compared to fossil diesel. However, this reduction must be substantiated through recognized certification schemes such as ISCC (International Sustainability and Carbon Certification) or RSB (Roundtable on Sustainable Biomaterials), in accordance with RED III and ISO 14040.

Technical Differences Between FAME and HVO

HVO, or Hydrotreated Vegetable Oil, is also a liquid biofuel but produced through a completely different process. Whereas FAME results from the esterification of fatty acids with methanol, HVO is made by treating oils or fats with hydrogen. This process, called hydrotreatment, removes all oxygen atoms from the molecules, producing a paraffinic fuel that is chemically almost identical to fossil diesel.

Due to its molecular structure, HVO is fully compatible with standard diesel engines. It meets the European EN 15940 standard for paraffinic diesel and can be used without technical modifications. Because HVO contains no oxygen, it is far less prone to aging, water absorption or microbial contamination. Whereas FAME can cause sludge formation or blockages during long-term storage under humid conditions, HVO typically remains trouble-free. This chemical stability enhances reliability and reduces maintenance requirements.

Performance differences are also clear. HVO has nearly the same energy density as fossil diesel and a high cetane number of around 80, enabling rapid ignition and efficient combustion. FAME has about thirteen percent less energy per liter, which may result in slightly higher fuel consumption in practice.

Emission measurements show that pure FAME (B100) can emit up to ten percent more nitrogen oxides (NOx) than fossil diesel in some engines. This depends on engine type, calibration and operating conditions. HVO generally performs better in this regard: NOx emissions typically remain the same or decline slightly, especially when combined with modern exhaust after-treatment systems such as SCR catalysts.

Bio-LNG, GTL and Fossil LNG as Alternatives to FAME

A frequently cited alternative to liquid biofuels in inland shipping is bio-LNG. This fuel consists of liquefied biomethane, typically produced by digesting organic waste such as manure, sewage sludge or food and garden waste. When managed through a well-organized supply chain, bio-LNG can be nearly climate neutral across the entire fuel life cycle. However, its application requires specific engine types, such as LNG Otto engines or dual-fuel systems, along with cryogenic storage tanks. For existing inland vessels, this often entails extensive and costly modifications, making large-scale use difficult in the short term.

Fossil LNG, or liquefied natural gas, has a lower theoretical CO2 output per energy unit than conventional diesel. In practice, however, its actual climate benefit is limited once methane slip is included. This refers to unburned methane emissions during bunkering, exhaust or tank venting. As a result, total greenhouse gas reduction is generally limited to five to ten percent. Still, fossil LNG offers clear benefits for local air quality, as the fuel contains virtually no sulfur or particulate matter. Depending on engine type and load, NOx emissions may be up to eighty percent lower than those from conventional diesel engines.

A third alternative is GTL, or Gas-to-Liquid. This synthetic diesel is produced from natural gas through the Fischer-Tropsch process, which converts gaseous hydrocarbons into liquid fuel components. GTL is paraffinic, completely sulfur-free and suitable for use in standard diesel engines without technical modifications. Combustion is clean, with reduced soot formation and sometimes slightly lower NOx emissions. However, as GTL is derived from fossil sources, it does not contribute to long-term CO2 reduction. It does not meet the RED III definition of sustainable fuels and has limited policy relevance within climate or blending obligations.

Environmental Impact and Practical Considerations in Using FAME

FAME can significantly reduce greenhouse gas emissions, particularly when produced from high-quality waste streams such as used cooking oil or non-edible animal fat from categories 1 or 2. When the production process is efficient and sustainability is certified under schemes such as ISCC or RSB, the fuel meets the stringent requirements of RED III and ISO 14040. This aligns with life cycle analysis methods and delivers a meaningful CO2 reduction compared to fossil diesel.

However, using FAME onboard requires attention to operational details and fuel management. Due to its cleaning properties, initial use can loosen deposits in tanks and fuel lines, which may clog filters and disrupt the fuel system. Many shipping companies therefore carry out preventive tank cleaning or stock extra filters when switching to blends above B20.

FAME is also more susceptible to microbial contamination, as it absorbs water more easily than fossil diesel. In humid environments, bacteria and fungi can develop rapidly, forming a biofilm at the fuel-water interface that can block fuel systems and damage injectors. Preventive measures are essential. Regularly draining water from the tank bottom, using effective water separators and adding biocides when needed can help mitigate these risks.

Cold weather resistance is another consideration. FAME made from saturated fats often has a relatively high Cold Filter Plugging Point (CFPP). At low temperatures, crystals may form that impede flow. To prevent winter malfunctions, it is advisable to use only blends with certified low CFPP values. Heated day tanks and heat tracing on fuel lines can also help.

Infrastructure, Market Acceptance and Policy Frameworks for FAME

A major advantage of FAME is its compatibility with the existing inland shipping bunkering infrastructure. Storage tanks, pipelines and shore-based pumps require no modifications. Blends up to B30 can be handled through standard diesel distribution networks without technical changes. This sets FAME apart from alternative fuels such as LNG or methanol, which require specialized or cryogenic bunkering systems.

Fuel suppliers such as FincoEnergies and Oliehandel Terlouw offer standard blends such as B15 and B30 via conventional bunkering stations. These blends are prepared just prior to delivery and stored under controlled conditions to ensure fuel stability and quality, in accordance with EN 14214.

Practical experience with FAME in inland shipping is growing rapidly. In 2024, companies including VT Group and Dekker Groep conducted long-term demonstration voyages using B30 under normal operating conditions. Results confirmed that high-quality FAME blends, when applied properly, do not cause structural technical issues. Still, it remains crucial for shipping companies and shipowners to observe basic precautions such as maintaining tank hygiene and replacing fuel filters on time. Structural onboard modifications are generally unnecessary.

From a policy perspective, FAME aligns well with European climate targets. The fuel meets the sustainability criteria of the revised Renewable Energy Directive (RED III) and can count toward national renewable transport energy quotas. Certified FAME, for instance with an ISCC or RSB label, qualifies for CO2 reporting by shippers and clients. It is also eligible under existing assessment frameworks such as the Green Award and the CO2 Performance Ladder.

To further promote FAME, additional policy measures and fiscal incentives may prove effective. These include excise duty reductions, CO2 compensation schemes or performance-based rewards for demonstrable emission reductions. Such tools lower the threshold for market acceptance without burdening shipowners with significant investment costs.

FAME as a Transitional Fuel Toward 2030 and 2050

In the short term, FAME offers a practical pathway to reduce CO2 emissions in inland shipping. Since the fuel can be used in existing diesel engines and bunkered via current infrastructure without technical adjustments, FAME provides an accessible option for shipowners aiming to comply with the binding reduction obligations under the revised Renewable Energy Directive and Regulation (EU) 2023/2417. This allows significant emission reductions without immediate investment in new vessels or engine configurations.

Over the medium and long term, however, FAME faces clear limitations. The availability of suitable feedstocks, such as used vegetable oils and non-edible animal fats, is limited. As other sectors, including road transport and aviation, increasingly rely on these waste streams, pressure on feedstock markets will intensify. Furthermore, FAME remains a combustion-based fuel. Despite its biogenic nature, combustion always results in CO2 emissions, even when considered circular in a life cycle analysis. In light of Europe’s ambition to eventually transition to zero-emission shipping, FAME is not a permanent solution. Its use is expected to decline gradually after 2035 in favor of zero-emission alternatives such as e-methanol, hydrogen or ammonia.

Nonetheless, FAME will remain a key link in the inland shipping energy transition over the coming years. It enables substantial CO2 reductions before 2030, thereby creating policy space for the gradual implementation of long-term solutions. As long as fuel quality is ensured and application is managed carefully, FAME remains a strategically valuable tool. It helps shipowners reduce their ecological footprint, supports policymakers in meeting EU climate targets and allows fuel suppliers to gain experience in sustainable distribution within existing logistics chains.

Frequently Asked Questions About FAME in Inland Shipping

FAME blends up to and including B20 (20% methyl esters) can generally be used in most inland shipping engines without technical modifications, provided that the engine manufacturer explicitly authorizes it. Blends up to B7 fall within the scope of the European diesel standard EN 590. Higher blends, such as B20, fall outside this standard and require separate approval, typically based on EN 16709 or customer-specific specifications. Several manufacturers have approved B20 for engines built from approximately 1990 onwards. In such cases, no adjustments are required to injection systems, fuel pumps or tanks, making the switch relatively straightforward.

For older engines or installations where material condition is unknown, it is advisable to inspect rubber components in advance. Gaskets, hoses and seals made of natural rubber (NR) or nitrile rubber (NBR) may degrade, swell or harden after prolonged contact with FAME. This increases the risk of clogging, leakage or reduced return flows and may compromise system reliability.

Many shipping companies therefore choose to proactively replace vulnerable components when using blends above B20. Materials resistant to biodiesel, such as fluoroelastomer (FKM/Viton) or PTFE, are commonly used. For the use of B30 or higher, it is strongly recommended to consult the engine supplier beforehand. This is essential to document material compatibility, safeguard technical specifications and maintain warranty conditions. When using pure FAME (B100) or high blends over extended periods, test voyages are sometimes conducted in which critical components and return lines are actively monitored for leakage, pressure fluctuations and temperature changes.

FAME has a cleaning effect that can loosen old deposits in tanks, lines and filters during initial use. Therefore, for blends from B15 upwards, it is advisable to clean the fuel tank beforehand or empty it completely. In the first few weeks after switching, fuel filters require extra attention. They may clog more quickly than usual, requiring more frequent replacement. Many operators carry extra spare filters during this start-up phase, especially under variable loads or when using blends above B20.

In addition to filter management, active water control is crucial. FAME is hygroscopic and absorbs water more readily than fossil diesel. Periods of inactivity and high humidity increase the risk of microbial contamination. Bacteria and fungi can develop at the fuel-water interface, leading to the formation of biofilm (diesel bug). This slimy layer can clog filters and damage injectors and fuel pumps.

Preventive measures are essential to avoid these issues. Regularly draining the tank bottom removes condensation and reduces the risk of bacterial growth. Fine-mesh water separators installed ahead of the main filters provide additional protection. When the contamination risk is elevated, a suitable biocide can be added in consultation with the engine manufacturer. Some operators choose to have injectors and fuel pumps inspected during the first hundred operating hours to detect early signs of fouling or deposit formation.

By applying these preventive measures, system reliability is maintained and performance and warranty conditions remain intact during and after the transition to FAME.

FAME has a limited shelf life of approximately six months, depending on storage conditions. Due to the presence of oxygen in its molecular structure, this biofuel is susceptible to oxidative degradation. During long-term storage, quality issues may arise, such as discoloration, acidification, gum formation and sludge buildup. These processes increase the risk of clogging in filters, pipelines and injectors. According to the European fuel standard EN 14214, FAME must be consumed within this timeframe or replaced in time to prevent technical issues.

For inland vessels, it is advisable to use FAME only for short-term supply or to work with freshly delivered batches. During seasonal lay-ups, such as winter idle periods, it is wise to consume most of the remaining fuel or dilute it with fossil diesel. If permitted by the fuel supplier, an antioxidant can be added to improve storage stability.

Filling the tank to capacity also helps reduce contact with oxygen, which slows oxidation. Avoid direct exposure to sunlight and high temperatures. By consistently applying these management practices, fuel quality can be preserved during onboard storage and the risk of system contamination significantly reduced.

FAME can be safely used in winter, provided that blends with sufficient cold-weather properties are selected. Biofuels produced from highly saturated fats, such as animal fat or palm oil, naturally have a higher Cold Filter Plugging Point (CFPP). At low temperatures, crystals or flakes may form in these fuels, obstructing flow and potentially causing blocked filters or engine shutdowns.

To mitigate these risks, fuel suppliers offer specially formulated winter-grade blends up to B30. These blends feature adjusted fatty acid profiles and cold stabilizers and comply with EN 590 requirements. They are suitable for use at temperatures down to approximately –20 °C. When purchasing, it is important to verify that the actual CFPP value is documented, as cold stability may vary by batch.

Onboard cold-weather performance can be further improved by using heated day tanks, electric heat tracing on fuel lines and installing fuel filters in temperature-controlled compartments. In exceptional cases, it may be necessary to temporarily switch to a lower blend ratio or certified winter diesel.

During freezing conditions, filters should be checked regularly for signs of crystallization, and a sufficient supply of spare filters should be kept onboard. This is particularly important during cold starts or after prolonged lay-up to ensure reliable fuel delivery.

FAME blends such as B15 and B30 are widely available in the Netherlands through conventional bunkering stations. Suppliers including FincoEnergies, Oliehandel Terlouw and GoodFuels offer standard blends, generally certified under recognized sustainability schemes such as ISCC or RSB. Since distribution takes place via the existing diesel infrastructure, no technical adjustments are needed to storage tanks, piping systems or pumps. Availability is also growing in Germany, Belgium and France, driven in part by the phased implementation of the revised Renewable Energy Directive.

Compared to fossil diesel, FAME is typically slightly more expensive but remains significantly cheaper than synthetic alternatives such as HVO. The price difference often amounts to less than ten euro cents per liter and depends on factors such as the feedstock used, for example used cooking oil or non-edible animal fat, and the prevailing market conditions. Certified waste-based blends may also qualify for fiscal incentives, including excise tax reductions and access to CO2 compensation schemes.

Within frameworks such as the CO2 Performance Ladder and the Green Award, certified FAME represents a cost-effective solution. It allows shipping companies and shipowners to demonstrably reduce emissions without major investments in retrofits or engine replacements. As such, FAME offers a practical route to decarbonization within the technical and logistical boundaries of today’s inland shipping sector.

Within approved blending limits, the engine warranty generally remains fully valid. Most engine manufacturers recognize B7 as a standard fuel under the European EN 590 diesel specification. Some brands also permit the use of B20 for engines built from 1990 onwards, provided this is explicitly stated in the product specifications or manual.

For blends with higher biocomponent content, such as B30 or B100, prior written approval from the manufacturer is required. Depending on engine type, additional conditions may apply, such as the execution of test procedures or monitoring during the first operating hours. Approval is valid only if the fuel complies with EN 14214 and is applied within the specified tolerances.

It is advisable to check in advance whether certain components are sensitive to FAME. In some cases, hoses, gaskets or seals may need to be replaced proactively, particularly if made from natural rubber or other materials not resistant to biodiesel.

As for emission certification, the official type approval is linked to fossil diesel as the reference fuel. In practice, many manufacturers accept the use of FAME, provided the engine continues to meet applicable emission limits. This includes, for example, engines with a Stage V certificate under Directive 2016/1628/EU or engines with a CCR2 declaration. When using alternative fuels such as FAME, an additional manufacturer’s statement may sometimes be required, or even partial recertification, depending on the exact blend and its effect on emission behavior.

It is therefore essential that the engine always operates within the fuel specifications defined by the manufacturer. Only then can the technical documentation remain valid and compliance with emission regulations be reliably demonstrated, including during inspections or audits.

FAME produced from waste streams such as used cooking oil or animal fat can yield CO2 reductions of between 80 and 90 percent compared to fossil diesel. This saving applies to the full well-to-wheel emissions and is substantiated through life cycle analysis according to ISO standard 14040. The exact reduction depends heavily on the feedstock and the underlying data used in the applied LCA methodology.

Under the revised European RED III directive, this reduction is recognized as sustainable. The maximum savings are achievable with pure B100 made from certified waste streams. At lower blend ratios, the CO2 reduction decreases proportionally. For example, B20 typically provides around a fifteen percent reduction, and B30 delivers between twenty and twenty-five percent, depending on feedstock origin and production chain efficiency.

FAME also contributes to lower local emissions such as particulate matter, carbon monoxide and unburned hydrocarbons. However, in older engines, nitrogen oxide emissions may increase slightly, with rises of up to ten percent when using pure FAME.

In modern engines with Stage V certification and after-treatment systems such as SCR catalysts and diesel particulate filters, this effect is almost entirely neutralized. Certified FAME, for example with an ISCC or RSB label, also qualifies for emission reporting under schemes such as the CO2 Performance Ladder and the Green Award.