LuminUltra, a microbial monitoring company, has highlighted concerns over the quality of some compliant fuels as the shipping industry gears up for IMO 2020
“Less sulphur means more bugs,” commented microbial monitoring company LuminUltra’s newly appointed director of global business development Patrick Taylor. He was referring to the blending of biodiesel with HSFO and distillates, which go towards reducing the amount of SOx emitted during the combustion process.
“The addition of biodiesel will reduce the sulphur content, but ship operators do need to be aware this can result in increased microbial influenced corrosion,” he said.
In the ballast water treatment technology market, LuminUltra provides testing kits to monitor the efficiency of the treatment process, but the company also supplies a wide range of monitoring kits including identification of microbial elements in fuel.
“If compliant fuels are not regularly monitored for their microbiological content, then at the very least biofilm will form and clog up the fuel filters. In the worst case, if microbial growth goes unchecked, then we are likely to see an increase in rapid microbiological-induced corrosion of even the most well-maintained fuel tanks and pipework,” said Mr Taylor.
He pointed out that the high sulphur content of residual fuel has been an “excellent inhibitor”, preventing the build-up of microbial growth and, consequently, the microbial induced corrosion of fuel tanks and systems.
“There is an increased biodiesel content in Marine Gas Oil (MGO) and we are seeing High Sulphur Fuel Oil (HSFO) now being blended with recovered distillates to reduce the sulphur level. As biodiesel has a high water content, these new fuels can be nutrient-rich breeding grounds for microbiological growth. There are real risks, real safety concerns,” he said.
Microbial influenced corrosion tends to fall into two camps: aerobic, where microbes require oxygen, and those that don’t, anaerobic. Water is the elixir of life for both these types, with microbes requiring little to form colonies and expand.
Yet while there is still a lack of information on water absorbance in biodiesel/diesel blends, research has shown that at constant relative humidity, biodiesel absorbed 6.5 times more moisture than diesel.
Referring to a paper published in 2016, in Volume 108 of International Biodeteriation & Biodegradation, published in 2016 by Elsevier1, Taylor said that a strain of fungus degraded biodiesel at “a phenomenal rate” and resulted in enhanced 1018 steel corrosion due to acidification.
To help shipowners verify the microbiological content of new 2020 compliant fuels, LuminUltra’s Quench-Gone Organic Modified (QGO-M) test kit is available to measure ATP (Adenosine Triphosphate), the primary energy carrier for all forms of life. The test kit, specially designed for organic-based samples, such as fuels, lubricants and oily brines, includes special provisions to neutralise organics prior to analysis, allowing ship operators and crew to quickly measure total microbiological concentration with a wide detection range and no assay interference. Results become available in less than five minutes, according to LuminUltra.
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1: Biodegradation of biodiesel and microbiologically induced corrosion of 1018 steel by Moniliella wahieum Y12 (Travers H.Ching, Brandon A. Yoza, Ruijin Wang, Stephen Masutani, Stuart Donachie, Lloyd Hihara, Qing X. Li.)