Beyond LNG: Alternative gas fuels advance

LNG has successfully been put on vessels other than gas service providers, of course , and has demonstrated the benefits as a clean, affordable alternative to liquid fuels. However it has a disadvantage, and that is within the onboard storage and running required. Not only does this include bulky and expensive gear, despite the best efforts from the engine and fuel providers, as well as classification societies, a few safety-related concerns remain. Gas does not have to be stored pressurized, it can be merely compressed, as well as CNG has been touted like a marine fuel, but for boats other than CNG carriers the dimensions of tank requited is likely to restrict it to vessels working on very short variety, such as tugs and seaside ferries.

Other gases can be found, of course. And although they usually do not solve the LNG queries - arguably bring concerns of their own - they do appear to be gaining ground as practical alternative fuels for delivers.

Methanol is one such fuel. The Stena Line shipping ferry Stena Germanica has been converted to run it is Wartsila four-stroke engines upon methanol, operating between Gothenburg and Keil. According to Stena, emissions from methanol tend to be roughly the same as for LNG, but the fuel is easier in order to process and does not place the exact same demands on infrastructure.

Methanol can be produced from natural gas, fossil fuel, biomass or even carbon dioxide, and also promises cuts in emissions of around 99% SOx, NOX by 60%, particles 95% and 25% CARBON DIOXIDE compared to conventional marine energy sources.

The same gas has been effectively demonstrated by MAN Diesel powered & Turbo as a feasible fuel for large two-stroke engines. Unlike the four-stroke gas and dual energy engines, and two-strokes utilizing a low pressure gas program, which use the Otto period when running on gasoline, MAN maintains the Diesel-powered cycle for both coal and oil operation, which it states avoids any change in energy density or load reaction, results in no methane slide, and hence higher carbon emissions, and avoids risk of banging. The Diesel cycle is actually maintained too for the ME-LGI version of MAN’s propane engines, which employ a gas booster valve to allow procedure with low-pressure, low flashpoint fuels including methanol.

The organization has received seven orders with regard to methanol-fuelled two-stroke engines to be able to power methanol carriers for many different owners. Vice president along with head of R&D, Søren H. Jensen, says: “A number of years ago we recognized the need to develop an engine which could run on more environmentally-friendly, competitively-priced fuels as an alternative to MDO/MGO. We expect the ability of the ME-LGI motor to run on sulphur-free powers offers great potential. Methanol carriers have already operated in sea for many years. With a worthwhile, convenient and economic gasoline already on-board, exploiting the fraction of the cargo for you to power a vessel is sensible. ”

Development of MAN’s methanol engine, which operates in 95% methanol and five per cent diesel, was carried out along with long-term partner Alfa Laval. Alfa Laval’s Monza lab in Italy has developed any fuel conditioning system regarding low-flashpoint fuels, such as methanol, ethanol, DME and LPG. In addition , Alfa Laval would be to explore new booster techniques for these fuel alternatives, in whose common denominator is a lower flashpoint below 60°C. The following stage in development is really a fuel conditioning system for LPG fuel.

“Low viscosity, a low boiling point in addition to high corrosiveness make energizes like methanol a particular problem for fuel conditioning devices, ” says Paolo Golla, head of Alfa Laval’s FCM product centre.

“Since methanol has a flashpoint less than 60°C, current class guidelines are not applicable, ” claims Mr Golla. “The course notation must be developed within pace with the technology, here we are extremely proud to become part of the process. ”

Within the large four-stroke field, Wärtsilä has announced that their 50DF marine engine continues to be successfully tested and licensed to run on ethane (LEG).

The test programme was in combination with gas tanker driver Evergas, whose CEO Steffen Jacobsen says: “We are extremely pleased that the Wärtsilä motors will be capable of utilising ethane boil-off gas as energy resource. It increases our functional efficiency and improves versatility in the bunkering of heats up. All in all it results in a substantial reduction in operating costs, whilst also providing a minimal environment footprint. It also enables us to provide our customers increased overall flexibility, which has a monetary value to them. inch

According to Wärtsilä, the capability to help efficiently burn ethane boil-off gas as engine energy significantly reduces the need for natural gas re-liquefaction during the voyage. Which means that less power is needed intended for cargo handling, adding to effectiveness and lowering the ship’s overall environmental impact.

The business adds that the 50DF may meet IMO Tier 3 regulations without need associated with secondary measures using possibly LNG or LEG because fuel, and can seamlessly change between LNG, LEG, HFO or distillate without being interrupted or the need for hardware customization.

"This is yet another significant success for Wärtsilä's multi-fuel technologies. The option to utilise ethane gas as a marine gas further extends the gasoline flexibility of our DF powerplant portfolio. It also provides another option to achieve compliance using the IMO's stringent Tier 3 legislation, " said Lars Anderson, vice president, engine product sales, Wärtsilä Ship Power.

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