By Capt. Neeraj Bharti, Founder, Master Mariner · Published · 2 min read
"Biofuel blends after DPP: extra checks before loading FAME or HVO grades"
Biofuels and biofuel blends are now ordinary cargoes for product tankers. They bring their own preparation questions, and they create one of the most talked-about contamination risks in the clean trade: FAME ending up in jet fuel. If the first clean cargo after a DPP changeover is a bio grade, or if the next cargo after a bio grade is jet, a few extra checks are worth the time.
FAME and HVO are different
- FAME (fatty acid methyl esters, often called biodiesel) is chemically different from petroleum diesel. It can cling to surfaces, attract water and, in some conditions, support microbial growth. Even small traces can be a problem for jet fuel.
- HVO (hydrotreated vegetable oil, sometimes called renewable diesel) is chemically closer to fossil diesel and generally behaves more like a conventional product, though charterers may still set their own requirements.
Always go by the product's specification and the charterer's instructions, not the general label.
Extra checks before loading a bio grade after DPP
- Coating compatibility. Check the coating maker's resistance list for the specific product and blend ratio.
- Dryness. FAME attracts water; tanks, lines and pumps need to be properly drained and dry.
- Sulphur and colour. Bio blends sold into low-sulphur markets are just as sensitive as ULSD. See fuel oil to gasoil or ULSD.
- Cleanliness of the whole system, as for any clean cargo after dirty. See lines, pumps and heating coils.
- Heating needs. Some bio products have cold-flow limits and may need gentle heating, so coils must be clean and tight.
After a bio cargo: the jet question
If jet is planned after a FAME-containing cargo, charterers often restrict this through previous cargo rules and may require extra cleaning and testing. Check those rules before fixing. See Jet A-1 after dirty cargo.
Planning
Treat a bio grade as a clean cargo with additional water, coating and previous-cargo questions. Get the specification, the charterer's previous-cargo rules and the coating resistance list before writing the cleaning plan. See reading HM 50 and the DPP to CPP changeover guide.
How Cleanship helps
We prepare tanks for clean and bio grades after dirty cargo, from our bases at Fujairah and in India. See our DPP and CPP tank cleaning service or contact us.
Sources & further reading
Frequently asked questions
What is the difference between FAME and HVO?
FAME is biodiesel made of fatty acid methyl esters and behaves differently from fossil diesel. HVO is hydrotreated vegetable oil and is chemically closer to fossil diesel.
Why is FAME a concern for jet fuel?
Even small traces of FAME can put jet fuel off specification, so charterers often restrict jet after FAME-containing cargoes and may require extra cleaning and testing.
Do biofuel cargoes need dry tanks?
Yes. FAME in particular attracts water, so tanks, lines and pumps should be properly drained and dried.
Should coating compatibility be checked for biofuels?
Yes. Check the coating manufacturer's resistance list for the specific product and blend ratio before loading.
- FAME tank cleaning
- HVO cargo tank preparation
- biodiesel tanker cleaning
- biofuel blend previous cargo
- FAME contamination jet
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