Navigating the Future of Maritime Sustainability: The Role of Biofuels

Introduction: The Imperative of Decarbonization

The maritime industry, contributing nearly 3% of global greenhouse gas (GHG) emissions, faces growing pressure to decarbonize. Biofuels, compatible with current engine technologies and capable of significantly reducing emissions, have emerged as a promising solution. This paper explores biofuels’ potential in the maritime sector, focusing on their benefits, challenges, safety considerations, and key drivers of adoption.

Understanding Biofuels: A Primer

Biofuels are derived from various sources, classified into generations based on feedstock and production methods:

1. First Generation: Produced from food crops (e.g., rapeseed, soybeans) through conventional transesterification. Fatty Acid Methyl Esters (FAME) defined by the specifications of EN 14214 and ASTM D 6754, a common type, reduce particulate matter and sulfur oxides (SOx) but raise sustainability concerns due to competition with food resources.‍
2. Second Generation: Created from non-food biomass like waste oils and agricultural residues. Hydrotreated Vegetable Oil (HVO) defined by the paraffinic fuel specification EN 15940, chemically similar to fossil diesel, offers superior combustion with reduced dependency on food-based feedstocks. Other examples include Dimethyl Ether (DME) and Pyrolysis Bio-Oil.‍
3. Third Generation: Derived from algae, which grow on non-arable land, avoiding competition with food production. Algae-based biofuels are lipid-rich but remain underdeveloped commercially. Bio-LNG (Bio-Methane), produced from organic waste and biomass, is an example of a fuel bridging second and third generations. It can be used in gas engines on LNG-powered ships.‍
4. Fourth Generation: Uses genetically engineered organisms and carbon capture techniques, targeting an even lower carbon footprint but still in the research phase.

Table 1: Biofuel Generation Comparison

The Case for Biofuels in Maritime Applications

Readiness of Biofuels 

Biofuels are increasingly recognised as viable “drop-in” fuels, capable of replacing  conventional fuels in existing engines with minimal modifications.  The maturity of biofuel options has progressed significantly, with several types notable FAME and HVO, already integrated into shipping operations. Trials, such as those conducted by GCMD and Hapag-Lloyd, demonstrate the effectiveness of biofuel blends, like B30 (30% biofuel, 70% VLSFO), in reducing emissions by approximately 28%. Enhanced supply chain transparency, bolstered by tracer technologies to verify fuel origin and quality, has further strengthened biofuel credibility.

Despite these advances, challenges remain in scaling up production. Feedstock limitations, infrastructure demands, and competition from other sectors, such as aviation’s increased use of Sustainable Aviation Fuel, impede broader biofuel availability. Current production volumes primarily support blending rather than full replacement of conventional fuels. Nevertheless, regulatory frameworks and industry interest are driving investment in biofuel scalability, with the International Energy Agency (IEA) projecting a 20% annual growth rate, reaching 58 million metric tons by 2030 .

Advantages and Disadvantages of Biofuels

Factors Propelling Biofuel Adoption

Regulatory Pressure

The EU’s “Fit for 55” package, including Monitoring, Reporting, and Verification (MRV), Emissions Trading (ETS), and FuelEU Maritime, is driving the maritime industry toward cleaner fuels and stricter accountability within the European Economic Area (EEA). MRV ensures emissions transparency, ETS functions as a cap-and-trade system that limits allowable GHG emissions, and FuelEU establishes GHG intensity limits for fuels.  Rising annual costs for non-compliance under ETS and FuelEU compound the financial burden on non-compliant operators and threaten their competitiveness, removing the economic advantage of cheaper, high-emissions fuels. These regulations promote low-carbon alternatives like biofuels and e-fuels, accelerating the industry’s shift to green solutions in line with the IMO and global decarbonization goals.

Growing Industry Interest

Biofuels’ compatibility with existing engines makes them a cost-effective option for shipowners facing new regulations without the expense of retrofitting. In early 2024, one-third of newbuild orders included alternative fuel options, signalling a strong market shift. This includes significant orders for vessels capable of using biofuels, alongside other alternatives like LNG, methanol, and ammonia .

Economic Considerations

The feasibility of widespread biofuel adoption depends on feedstock availability and production scalability. While biofuels currently carry a price premium over conventional fuels, they integrate well with existing infrastructure, allowing for near-term decarbonization without engine modifications. As production scales and carbon pricing develops, biofuels are projected to become more cost-competitive by 2030, reinforcing their appeal as a practical solution for the industry.

Table 2: Biofuel Cost Development

Case Study: Spar Lynx’s Biofuel Implementation

Spar Shipping AS, Fleet Management Limited, and GoodFuels completed a 10-day biofuels trial using various biofuel blends to assess emission profiles. The bulk carrier vessel, the Spar Lynx underwent trials with 100% biofuel, a blend of 30% biofuel and 70% Very Low Sulfur Fuel Oil (VLSFO) (referred to as Biofuel 30) and VLSFO alone. During the trials, the vessel demonstrated that FAME-type biofuel blends produced average NOx emissions comparable to traditional distillate (DM) fuels. However, a concerning trend emerged: transitioning to 100% FAME biofuel (B100) led to increased NOx emissions compared to DM fuels (Chart 1). This highlights the need to evaluate the emissions profiles of different fuel options carefully.

In terms of sulfur oxides (SOx), the Spar Lynx achieved an impressive 85% in emissions reduction, showcasing the effectiveness of advanced fuel options in minimizing harmful pollutants (Chart 2).

Additionally, the trials indicated that the tank-to-wake CO2 emissions were approximately 6% lower than VLSFO, the broader well-to-wake perspective showed a remarkable 75% reduction. These findings suggest that strategic implementation of biofuels could serve as an effective pathway toward decarbonisation, reinforcing the role of alternative fuels in meeting future regulatory and sustainability targets.

Closing Thoughts

Biofuels present a viable path for maritime decarbonization, as demonstrated by industry trials and Spar Lynx’s success. While managing NOx emissions through careful blend ratios is crucial, biofuels’ lifecycle CO2 reduction potential shows their real impact. Additionally, the use of biofuels can significantly reduce SOx emissions, contributing to improved air quality and health benefits. Biofuels certifications like those from the Roundtable on Sustainable Biomaterials (RSB) and International Sustainability and Carbon Certification (ISCC) can further strengthen confidence, ensuring sustainability and traceability. With the support of these trusted standards, alongside regulatory backing and the continued development of sustainable feedstocks and infrastructure, biofuels are well-positioned to help the maritime industry achieve meaningful emissions reductions in the years to come.