The shipping industry is actively seeking alternative fuel sources to meet regulatory requirements and voluntary emission reduction initiatives by ship owners. Among these alternatives, biodiesel is experiencing significant growth. Collaborations between refiners and ship owners have led to successful trials of various biofuels within shipping fleets.
VPS (Veritas Petroleum Services) plays a pivotal role in the transition towards decarbonization by participating in field trials that involve comprehensive testing of different biofuels.
Understanding biofuels involves familiarizing oneself with specific terminology:
Biofuels: Fuels produced from biomass, which can include plants, algae, or animal waste.
FAME: Fatty Acid Methyl Ester, a product obtained through the transesterification of vegetable oils, waste cooking oils, and animal fats.
Transesterification: This chemical process separates glycerin from fats or vegetable oils, yielding two main products: methyl esters and glycerin. Methyl esters are the primary components of biodiesel.
Biodiesel: A specific term that refers to methyl esters (FAME) sourced from either crop-based or waste-based feedstocks like vegetable oil and animal fat.
Drop-in Fuels: These biofuels can replace fossil fuels without requiring substantial modifications to engines or supply chains. An example is Hydrotreated Vegetable Oil (HVO).
Hydrotreated Vegetable Oil (HVO): A paraffinic fuel derived from vegetable oils and animal fats, produced through hydrogenation. Other fuels from agricultural and waste-based feedstocks include bio-ethanol, bio-methanol, FAME, and HVO.
eFuels: Fuels created using renewable energy sources, incorporating water and CO2 from the atmosphere, such as ammonia and green hydrogen.
The ISO 8217 standard outlines the quality requirements for fuels used in marine applications. According to this standard, FAME blended into fuels must meet the specifications set forth by EN 14214 or ASTM D6751.
Currently, the standard maintains a "de minimis" threshold of up to 7.0% volume FAME content (B7 blends) for distillate grades, including DFA, DFZ, and DFB. Although ISO 8217 does not directly address biofuel components, several of its testing parameters remain applicable.
The standard is under review by relevant working groups, and future revisions are expected to include more comprehensive measures for biofuel standards. Additionally, technical requirements established by the American Society for Testing and Materials (ASTM) are important, particularly ASTM D6751, which outlines the procurement requirements for bio feedstock, and ASTM D7467, which specifies standards for diesel fuel oil and biodiesel blends (B6-B20).
Biofuels can present compatibility challenges when in contact with certain materials. Below is a summary of materials commonly assessed for compatibility risks. It is essential to conduct risk assessments on a case-by-case basis to prevent issues of incompatibility.
Stability: Biofuels generally exhibit poor long-term stability. It is advisable to avoid storage beyond six months. In situations where extended storage is necessary, routine sampling and testing every three months should be conducted to assess oxidation stability, acid number, and water content.
Microbial Growth: The biodegradable nature of biofuels makes them susceptible to microbial growth, especially in the presence of water. The FAME content in biofuels has a strong affinity for water, which can lead to emulsions and foster microbiological growth. This growth may introduce sulphide-reducing bacteria that can corrode steel tanks. Adequate drainage and a cool storage environment are crucial to minimize condensation and heat, which can accelerate degradation.
Cold-Flow Properties: Biofuels generally have poor cold-flow characteristics, forming gel at temperatures around 0°C. Therefore, they should be maintained at least 10°C above their pour point to prevent gelling.
Polar Compounds: FAME can be polar, causing biofuels to adhere to tank surfaces and form deposits.
Transitioning to Biofuels: The solvency properties of biofuels can dislodge existing fuel debris, potentially clogging filters. It is prudent to clean tanks prior to using biofuels and to monitor filters and purifiers closely during the initial phases of biofuel integration.
Consumers considering biofuels should consult with their equipment manufacturers to confirm compatibility, especially for oily water separator systems, overboard discharge monitors, filters, and coalescers.
Emissions Reduction: Biofuels present lower carbon emission factors compared to traditional marine fuels like MGO, VLSFO, and HSFO. They can be blended with fossil fuels and utilized as 'drop-in' alternatives without requiring extensive modifications to modern marine engines.
Storage and Handling: While biofuels offer advantages, they also come with known storage, handling, and operational challenges that can be effectively addressed through a robust risk management strategy.
Collaborative Efforts: Numerous leading ship owners have successfully tested biofuels, yielding positive outcomes. Ship operators are actively collaborating with engine manufacturers, biofuel suppliers, testing laboratories, classification societies, and other stakeholders to advance the adoption of biofuels in the industry.
In conclusion, as the shipping industry continues to explore sustainable fuel alternatives, biofuels present a viable option that can contribute to reduced emissions and greater environmental responsibility. Through ongoing research, collaboration, and adherence to established standards, the transition to biofuels can pave the way for a more sustainable future in maritime operations.
