Published in the Dec/Jan edition of Bunkerspot.

By Steve Bee, VPS Group Commercial Director.

Introduction

Its very apparent, global shipping’s drive to decarbonise is well underway. The ship-building profile is changing dramatically, highlighted by the 2023 order book showing 539 new builds capable of running on low-to-zero carbon fuels, being ordered. Looking at Jan-Sept 2024, 49% of the gross tonnage on order were for vessels configured to be alternative fuels ready, with this specific order book growing by 24% year on year. Its obvious that shipping is keeping its options very much open and looking for as much flexibility as possible, when it comes to the fuel choices for it’s ships.

The industry currently bunkers 230 Million mt of fuel per year. Burning this fuel equates to emissions of 716M mt of CO2-equivalent, as the majority of the fuel burnt continues to be traditional fossil fuels. This is supported by studying VPS fuel sample receipt for 2023 which was, 54% VLSFO, 30% HSFO, 14% MGO and 1% each for ULSFO and Biofuels.

However, the list of environmental legislation and directives to reduce emissions from shipping is ever-increasing in order to reduce SOx, NOx, Particulate Matter, CO2, Methane and other Green House Gases.  It is this regulatory demand which is driving the developments of numerous alternative low-to-zero carbon fuels for marine use.

But it is biofuels, which currently offer an attractive and immediate path to CO2 reduction. As a “drop-in” fuel option, using existing delivery, storage, fuel-transfer and engine operation processes, biofuels provide a decarbonisation solution, with minimal change.

VPS has been and continues to be, at the forefront of fuels research & development and continuing our innovative development of test methods for such fuels. We are working on numerous biofuels projects with the Global Centre for Maritime Decarbonisation (GCMD), sea trials with ship owners and operators, plus working with both fuel suppliers and additive manufacturers to assist in their product developments.

Biofuels

So what’s the biofuels story today? We are seeing an exponential increase in demand based upon the number of biofuel samples we are receiving in our laboratories, linked to the actual metric tonnes of biofuel being delivered per stem. Between 2021 to 2023 biofuels samples received by VPS increased from 70,000mt to 558,000 mt delivered. This year biofuel samples received by VPS will surpass 700,000 mt of biofuels delivered.

Singapore exceeded 2023’s delivered quantity at the half-year point of 2024 and Asia Pacific more than trebled biofuel bunkerings vs last year, as we go into the final quarter of 2024.

Europe is on track to do 40% more than last year if delivery rates continue as they have been.

2024 has seen lower percentage bio-components, ie B10-B30 increase in demand, whilst a significant reduction in higher bio blends, ie B100.

This is likely to be price-driven, as the amount bio content of the fuel is at its premium versus traditional fuels. B20s running around 17% more and B30s running at 23% more than conventional fuels.

For FAME-based biofuels, there are six key quality considerations to take into account.

Firstly, Oxidation Stability, as FAME can oxidise and destabilise very quickly. As FAME destabilises, it becomes considerably darker in appearance, more viscous and much more acidic. VPS utilise three tests to establish a fuel’s level of stability: The Rancimat test, which is a deliberate aging test, where we look to implement a “traffic-light” assessment of Green for a > 8 hours result, Amber for a 5-8 hour result and Red for a<5 hour result. We can then use the Iodine Value test to measure the degree of unsaturation and potential reactivity of the biofuel and thirdly, the Polyunsaturated Fatty Acid content determination via GC, to measure Linoleic Acid and Linolenic Acid levels.

FAME has poor cold-flow properties and so we use the traditional tests of cloud point, cold-filter plugging point and pour point to determine these. Except when the blend is with a dark fuel, then we use the proprietary VPS Wax Appearance Temperature Test.

FAME can be very corrosive, so we test for Total Acid Number, but also undertake Copper and Steel corrosion testing as FAME can be corrosive towards certain surfaces.

As FAME loves water, this can create a breeding environment for bugs and so Bacteria/Yeast/Fungi testing is a key test to monitor the level of microbial activity.

Knowing the calorific value is essential and with fossil fuels this can be determined by a calculation within ISO8217. However, due to the higher oxygen content of FAME, this calculation is inaccurate for biofuels where the FAME content is greater than 10%. and therefore, the laboratory test ASTM D240 must be used to determine the energy content.

Many test to determine the renewable content of biofuel have poor repeatability and reproducibility. To overcome this, VPS have modified EN14078 to produce a much more accurate determination of renewable content, which is and will be, so key in ensuring correct levels of carbon taxation is paid by vessels.

VPS & The GCMD

To really push forward the understanding of biofuels for maritime applications, the work between VPS and the Global Centre for Maritime Decarbonisation, is proving to be an innovative partnership. Already completed is the following project:

“Tracking the Propensity of Biofuels Degradation Across the Maritime Supply Chain” Published June-24. This project looked into understanding the propensity of degradation of FAME and tracing FAME quality in GCMD’s end-to-end supply chains. It also looked to understand the previous and now current ISO specifications for FAME quality requirements, whilst also focusing on additional FAME tests methods needed such as Peroxide Value & Iodine Value for Auto-oxidation, Methanol Content & Free Fatty Acids for Hydrolytic Oxidation, and Microbial Count Test for Microbial growth.

One key question going forward is, “Is my biofuel truly sustainable”. FAME can include a varying mix of the different methyl esters, depending upon the feedstock source, for example using Palm Oil, or Sunflower Oil, or beef tallow, will see different FAME mixes to each other. FAME compounds are typically in the range of C14 – C20 with the naming convention detailed in the graphic below:

VPS has refined EN14103 (Determination of Ester Content of Fame) to enable the identification and measurement of individual  FAME components in neat FAME and in FAME blended residuals and distillates, to create a FAME fingerprint library, to help identify the source/feedstock. This is unique and innovative laboratory R&D undertaken by VPS and will be covered in an upcoming paper from the Global Centre for Maritime Decarbonisation, (GCMD), as part of a second joint project on biofuels. (Paper imminent)

An earlier VPS/GCMD project on supply chain quality control also looked into the use of a Fuel Marker/Tracer Project, where the biofuel quality is tracked throughout the supply chain utilising different types of tracer technology.

Then finally, Project Lotus which is a six-month ongoing project to trial the continuous use of a biofuels blend, comprising 24% FAME and 76% VLSFO, onboard a short-sea vehicle carrier calling at multiple ports. This will monitor the longer-term impact of continuous use of biofuels on vessel operations, covering:

Fuel quality of the biofuel blend which will be systematically tracked and monitored throughout the supply chain, from bunkering to onboard consumption under operating conditions. 

Fuel delivery systems via physical inspection of the fuel delivery system and purifiers will be conducted to monitor for potential seal leakages, corrosion, clogging etc.

Engine performance and working with engine OEMs, performing detailed inspections on engine components before and after switching to biofuels, along with a lubricating oil analysis to assess its efficacy in protecting the engine’s moving parts from wear and tear.

Case Study

A recent case study provides proof of why it is so important to know your biofuel’s components and bio-source. The case highlights a Ship Owner who had two vessels bunkering what they were told was a B100 biofuel in the port of Flushing in early 2024. The first Vessel experienced significant difficulties with blocked filters, delayed ignition and abnormal exhaust temperatures. As a result, the 2^nd vessel sent samples following the 1^st vessel’s issues. VPS found via GCMS-Acid Extraction Analysis, the B100 wasn’t 100% FAME but was actually: 40% FAME, 10% FAME bottoms and 50% Cashew Nut Shell Liquid (CNSL). All of which were bio-components but not FAME only. GCMS showed >2,000ppm of phenols in the form of Cardanol, which is the main component in CNSL.

Bio-Alternatives

Whilst FAME is the most common bio-component used within marine biofuels, HVO and CNSL are also considered as bio-options.

We know FAME is highly unsaturated causing high instability. It has lower energy content (37MJ/Kg), poor cold-flow properties, increasing acid number upon oxidation and prone to microbial growth.

Whereas Hydrogenated Vegetable Oil (HVO) is produced by hydrogenation making it more stable than FAME, with a higher energy content (44 MJ/Kg), better cold-flow properties, zero sulphur content, lower corrosivity, with little chance of microbial activity. The negatives to HVO, are the higher cost and lower levels of availability.

Then CNSL, which has good oxidation stability but as its phenolic, it is highly reactive and corrosive, but with medium energy content, good cold-flow properties and no microbial activity.

ISO8217:2024

The latest ISO8217:2024 revision, published in June 2024, now accounts for the presence of FAME, HVO, GTL, BTL, within the marine fuel quality standard. However, it doesn’t cover bio-materials such as CNSL, or TPO, to give two examples.

Table 1 for distillates and bio-distillate blends cover FAME up to 100%, ie B100, but doesn’t include the test for microbial growth.

Table 3 for Bio-residual blends, covers TAN, FAME content, Energy Content and Total Chlorides, but doesn’t cover, Cold-Flow properties in terms of WAT, Stability in terms of EN15751, chemical screening or microbial activity.

So, whilst VPS sees ISO8217:2024 as a major step forward as a standard covering the changing fuel mix, its not a comprehensive test slate. To provide further peace-of-mind to customers using biofuels, VPS have introduced a range of wider test parameters under our APS-Bio range of test bundles, covering FAME, HVO, CNSL, when blended with MGO, VLSFO or HSFO fuels, or 100% FAME or HVO.

As declared during SIBCON Conference in Singapore in October 2024, the existing Biofuel Standard WA2:2020 will be upgraded & launched in 2025. This new Singapore Biofuel Standard will align with the ISO 8217:2024 & also look at additional quality criteria of noteworthy importance.

Summary

As decarbonisation and legislation drivies the development of low-to-zero carbon fuels, demand for Biofuels is growing exponentially, especially B10-B30 blends in Europe and Singapore, as they provide an excellent way to achieve immediate reductions of emissions. However, to gain a much fuller understanding of biofuels as a marine fuel, numerous projects between VPS and the GCMD are providing greater insights into these fuels.

In addition, ISO8217:2024 now recognises biofuels containing FAME, HVO, GTL, BTL, but this revision is still not a comprehensive test slate, which has led to VPS developing the APS-Bio packages to provide greater peace of mind for our customers whose interest and commitment to biofuels is increasing.

All of this is evidence that the global shipping industry is well on its way and intent on delivering upon its decarbonisation goals, but with many challenges still to overcome.

For more information please contact Steve Bee at: steve.bee@vpsveritas.com