GCMD Reports on Biofuel Degradation Study

The Global Centre for Maritime Decarbonisation (GCMD) has released a report, “Tracking the Propensity of Biofuels Degradation Across the Maritime Supply Chain.”

The report includes findings from tracking the quality of FAME and FAME blends as they make their way through the supply chains and on consumption onboard vessels.

Unlike conventional marine fuels, FAME-based biofuels can be unstable since its natural oils and fats can slowly oxidize when exposed to atmospheric oxygen. When oxidation happens, FAME can degrade to produce by-products, like peroxides, alcohols, and sludge, all of which can impact engine life and performance.

Degradation can also be further accelerated by exposure to water, impurities, contaminants, light, and heat.

GCMD end-to-end supply chain trials detected no significant degradation of FAME under commercial operations conditions.

These findings complement existing results from laboratory-based studies in highlighting the importance of the environmental conditions under which testing is carried out.

As an example, a recent Olderndoff Carriers study that tested FAME under controlled and extreme conditions, including exposure to 5% water in the absence of antioxidants and at varying temperatures, provided quantitative evidence for degradation across a number of variables impacting fuel stability. Yet, commercial bunkering operations, bound by ISO 8217 specifications, mandate a maximum water content of 0.5%v/v, rendering the 5% water exposure scenario highly unlikely in actual practice. In the GCMD trial, the fuel aliquots collected at all sampling points showed that the water content in FAME are below the threshold specified by ISO 8217.

GCMD and partners have recently launched an additional pilot to investigate the impact of long-term use of biofuels on engines and fuel delivery systems. With focus on engine operations and performance, this pilot will provide complementary insights to harness the full potential of biofuels.

The report was co-authored by Dr. Prapisala Thepsithar, Director of Projects, and Dr. Sanjay C Kuttan, Chief Strategy Officer, at GCMD. It was reviewed by: Dr. Malcolm Cooper, CEO of VPS, Captain Rahul Choudhuri, President, Strategic Partnerships, VPS, and Ms. Monique Vermeire, Fuels Technologist at Chevron.