BAI · Brittany Ferries, France – Reduction of carbon footprint

Brittany Ferries

Brittany Ferries wanted to evaluate the enzymatic technology for XBEE fuels.

The ferry Mont St-Michel was selected to be the company’s laboratory vessel, with several objectives:

  • Demonstrate a reduction of carbon footprint and toxic gases.
  • To test the ability of the enzymatic technology to clean engines.
Brittany Ferries France Reduction of carbon footprint


During this campaign, a number of emissions were measured, notably sulphur dioxide.

In the context of the SO2 emission reduction targets set by the IMO, it would be interesting to assess the ability of the XBEE technology to have a positive effect on these emission levels.

Method used

The laboratory Ascal (now Eurofins), accredited by COFRAC and the French Ministry of Ecology and Sustainable Development, was selected to carry out the emission measurements.

Measurement schedule:

  • The first measurement was on October 8th 2006, before using XBEE enzymes. From 13 October, during each bunkering operation, the XBEE product was added at a dosage of 4,000:1 (1 litre of XBEE per 4,000 litres of fuel).
  • Second measurement was on November 8th 2006, after one month of using XBEE in the fuel.
  • Third measurement was on December 13th 2006, after two months of operation with XBEE fuel.
  • Fourth measurement was on March 29th 2007, after almost six months of operation with XBEE.
  • Fifth measurement on October 18th 2007 to close the full one-year test programme.

Note: Since the beginning of 2007, changes in the main engine number 4 and different fuel qualities alter the results. The fourth and fifth measurements were witnessed by two engineers from the French National Agency for Marine Affairs.

Finally, one year of work with XBEE enzyme-added fuels is observed through five measurement campaigns, each representing fifteen thirty-minute samples.

The measurements were carried out in the stack of the main engine Mak number 4, at a rate of three thirty-minute sequences, spread over a period of two hours, during which the engine was kept at a constant speed.

From the start of the measurements, 50 litres of XBEE were injected into the fuel each time the ship took on 200 tonnes of IFO 380, which it did twice a week.

Injection of XBEE at 1 per 4000 during each bunkering operation

The technical team installed a sprayer that sucked up the XBEE additive and injected it directly into the bunker line. The key was to treat all the fuel burned by the vessel during the evaluation period, in addition to cleaning the entire fuel system, starting with the IFO 380 storage tanks.


The results bring more or less the same observations, considering both the initial period of XBEE use of only 2 months, during which the technical operating conditions of the engines were very similar, and then later the parameters were very different from what they were on 11 October 2006.

O2 – A considerable increase in Oxygen, respectively +16.7% and +8.33%, shows a very substantial improvement of combustion.

CO2 – The evolution of the CO2 (carbon dioxide) concentration in the exhaust gases is always in line with the evolution of fuel consumption.

The reduction of CO2 emissions by -22.9% and -11.07% does not necessarily imply the same reductions in fuel consumption, but it is indisputable proof of its decrease. Although it is rather difficult to measure, given the various parameters.

CO – The evolution of CO (carbon monoxide) in the exhaust gases always reflects the evolution of combustion. Whether it is -42.9% or -36.36%, the combustion is clearly improved. And the reduction of particulate emissions by -40% also confirms this.

VOC – Reductions of -40.7% and -21.62%. The improved combustion quality allows a significant reduction in the number of unburned particles which are one of the main components of VOC (Volatile Organic Compounds).

SO2 – In line with CO2 emissions, a significant reduction in sulphur emissions has been demonstrated: -18%. In theory, the total sulphur release remains identical for identical fuel consumption; the enzymes contained in this fuel transform sulphur molecules into new sulphite and sulphate molecules.

The reduction of SO2 emissions is real, but must be correlated with the increase of sulphur particles contained in the total emissions. Whereas, the substitution of highly reactive SO2 by more stable compounds limits the environmental impact and is consistent with the objectives defined in MARPOL Annex VI.

NO and NOx – In the same way as CO2, the emission levels of NO (nitrogen oxide) and NOx (nitrogen dioxide) decrease respectively by -24% and -5%. This result demonstrates that XBEE has the capacity to reduce CO2 without altering NOx emission levels.

Particulates – The 40% reduction in the mass coming out of the exhaust confirms the improved combustion, which has also been verified by measuring other parameters.

This drastic reduction of carbon footprint is undoubtedly one of the most appreciable results. It is a tangible achievement for public health and for ships docking in ports close to urban areas, the latter having a strong interest in reducing their emission levels in the short term.

Brittany Ferries verified a reduction of carbon footprint at Mont St-Michel

At the end of December 2007, after 14 months of continuous operation with XBEE, the product is discontinued. On the other hand, the ferry enters the Remontowa shipyard in Gdansk, Poland, on January 8th, 2008.

The following comments come from Mak Med’s technical report, signed by Axel Hausmann and Benoît Vrignaud:

“We found the cylinder heads in very good condition. All heads were tested for cracks; none were found.

The cylinder liners were in very good condition. After intensive cleaning, we found the original polished surface. The rings showed no wear and were put back in place.

Another very positive impression was given by the pistons; we found burns on the combustion side of the piston heads. Furthermore, the rings were still in good condition and we did not find any carbon or lacquer build-up on the inner cooling surfaces of the crowns.

We checked two main bearings in each engine and decided to keep them in place for an additional 12,000 hours of operation”.


These observations are the translation of the previously measured results: dramatic increase of oxygen and very substantial reduction, -42.9% and -36.36% of carbon monoxide, reflecting a change in combustion.

This is also confirmed by another measurement: the -40% reduction in particulate emissions.

Such developments can only be the consequence of very clean engines. It is clear that these engines, being so clean after 30,000 hours of operation, are reducing their pollutant emissions and fuel consumption.




Roscoff, France

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XBEE is an enzyme technology compatible with all fuels, in all engines. This cleaning treatment disperses water and fuel-derived organic contaminants.

Consequently, XBEE helps to clean up the whole fuel system and eliminate carbon deposits in the engines, hence a reduction of the maintenance costs and gas emissions _ in particular CO2, NOx and particulates.

Finally XBEE reduces the fuel consumption.