Tue 16 Jan 2024 16:22 | Updated: Tue 16 Jan 2024 16:23

ISO 8217 formula 'not suitable' for gauging FAME fuel energy content: VPS


Accurate measurement can only be determined using calorimetry, says testing firm.



Algebra illustration.

VPS says the ISO 8217 equation is able to calculate the energy content of conventional fuels and distillates to a good degree of accuracy because of the empirical linear relationship between density and energy content; but this relationship does not hold when the fuel contains oxygenated compounds, such as FAME in biodiesel. Image: chenspec/Pixabay

VPS has published a white paper where it asserts that the existing ISO 8217 formula for calculating energy content — a key test parameter — is not accurate for fuels containing FAME, such as biodiesel.[1]

Energy content represents the amount of heat transferred within the combustion chamber during the burn process and indicates the available energy from the fuel. Higher energy content results in higher power generation and better combustion efficiency. The energy content has a direct impact on fuel economy and greenhouse gas emissions and is therefore an important parameter for ship operators to consider in preparation for the EU ETS.

In the VPS research paper, a number of conventional fossil fuels and biofuels with varying FAME content were measured using the ASTM D240 method and the energy content compared with that obtained using the ISO 8217 calculation method (which uses a formula specified in Appendix H of the International Marine Fuel Standard ISO 8217:2017).

The results show good correlation for conventional fuels and distillates, indicating that the ISO 8217 calculation method provides an acceptable degree of accuracy for measuring energy content in conventional fuel types. However, according to VPS, this correlation falls away at FAME content above 10%, thus demonstrating that the ISO 8217 calculation method cannot be relied upon to provide accurate energy content for fuel blends containing more than 10% FAME and that, for these blends, the accuracy of the calculation formula is not acceptable, and accurate energy content can only be determined by measurement using calorimetry.

"This inaccuracy," VPS says, "is due to the greater oxygen content of FAME ... as compared to conventional fuels (which typically contain very little oxygen)."

The ISO 8217 formula is only based on the linear relationship between density and energy content, VPS explains, but does not account for oxygen present in FAME.

As the FAME and the oxygen in the FAME are both variables, a linear relationship between the FAME and the energy content could therefore not be established in studies carried out on biofuels with varying FAME content.

For blends containing more than 10% FAME, VPS concludes that the accurate assessment of energy content requires direct measurement (rather than an equation calculation) using the ASTM D240 method, which uses an oxygen bomb calorimeter to determine the energy content.


Notes

[1] Sign up to a subscription plan to view notes and source information.

Verde Marine Homepage Delta Energy's ARA team shifts to newly launched Verde Marine  

Physical supplier offering delivery of marine gasoil in the ARA region.

Bunker delivery at anchorage. Bunker Holding launches carbon insetting capability  

Supplier aims to help buyers overcome the relative higher cost of alternative fuels via cost sharing.

Wärtsilä vessel design. Wärtsilä to supply Scale Gas LNG bunker vessel's cargo handling system  

New 12,500-cubic-metre supply tanker to be built by CIMC SOE.

The chemical tanker Aalborg at the Port of Barcelona. Peninsula launches B100 bunker vessel in Barcelona  

Chemical tanker Aalborg capable of supplying up to 100% bio component.

Peninsula office. Peninsula confirms maiden B30 deal in Zeebrugge  

NYK carrier refuelled with biofuel comprising 30% UCOME.

Risk chart outlining likelihood of bad bunkers Mitigating the risks of bad bunkers  

Article by Steve Bee, VPS Group Commercial Director; Dr Malcolm Cooper, VPS CEO; and Stanley George, VPS Group Science & Technical Manager.

Air Liquide and Vopak sign ammonia MoU. Air Liquide and Vopak to collaborate on ammonia project in Singapore  

MoU to develop infrastructure for ammonia import, cracking and hydrogen distribution in Asian city-state.

Wärtsilä NH3 Ammonia label. Wärtsilä launches Ammonia Fuel Supply System  

System available for liquid and gaseous fuel, gas and non-gas carriers, and newbuilds and retrofits.

Panagiotis Bastas, head of Greece office, Aurora Marine Fuels (AMF) New Greece manager at Aurora Marine Fuels  

Panagiotis Bastas named head of the company's Athens office.

Adrian Beciri, CEO of Ducat Maritime From greenwashing to 'wacky' bunker margins  

Interview with Adrian Beciri, CEO of Ducat Maritime.


↑  Back to Top