There was considerable uncertainty regarding which would be the best way of meeting future emissions / fuel requirements. Options include:

1. Water in fuel using emulsifying equipment, direct injection or spraying. Wartsila have an interesting graph comparing effects of the different types. You may wish to note the limitations of emulsion when compared to the other systems.
2. MAN have a trial unit on the Alexander Maersk vessel)
3. Scrubbers (Wartsila and Aalborg appear to be the most advanced at present)
4. Catalytic Converters (preferably before the Turbocharger)
5. Bergen in particular was very bullish about the installation of bunkering infrastructure in time to meet the 2020 target. Wartsila presented a Dual Fuel solution (belt and braces). 

According to both MAN and Wartsila there will be no one solution which will suit every vessel type. Where vessels are operating in the environmentally controlled areas (ECA) gas may well be the best solution. Gas is always a good solution for LNG carriers. Continued use of HFO with catalytic converters and scrubbers is likely to be economic for larger vessels trading worldwide.

There was an interesting discussion about the availability of different grades of fuel and the environmental costs in CO2 terms of refining more diesel as a proportion of the total. 

Low sulphur fuels have particular problems of lubricity (it is not the lack of sulphur which causes the problem, but the process which removes the sulphur also removed a number of other substances, and it is these which provide the lubricity). The solution is additives to replace the lubricity and stop the plungers and barrels sticking. Caterpillar provided an example of MDO also having high values of calcium which cause the plungers to stock.

From our lobbying point of view, the use of scrubbers and catalytic converters will require monitoring of the exhaust to ensure compliance. This may give us an opportunity to persuade IMO to change the regulations to get rid of the parameter system altogether and insist on monitors except perhaps for gas engines where they might not require either monitoring or the parameter system. 

Efficiency gains included conditioning monitoring, hull designs, propeller optimization, optimizing the equipment for normal operating speeds rather than trial speeds, reviewing use of equipment on board, trimming systems, weather routing, agreeing with charterers to plan arrival times more closely so that there is less waiting time etc. 

Bergen have introduced a system whereby the main engine is coupled to a generator / motor. In this way the main engine can produce both electric and propulsive power, but more importantly the system can work in reverse whereby the auxiliary generators can produce propulsive power by using the shaft generator as an electric motor. This enables all sorts of games to be played in order to optimize the fuel consumption to the power requirement. This was designed especially for offshore vessels.

EMISA (by James Hogg)