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"Volvo is adamant that DME has the potential to become a competitive alternative to fossil fuels"
Page 57
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advantages over rival alternative fuels, not least that it can be used in compression ignition engines with high efficiency.As already mentioned it is also cleaner-burning than diesel, and Volvo insists: "DME can have betterwell-to-wheer efficiency when produced from biomass compared to some other biofuels."
However, nothing's perfect.DME's downsides-Volvo calls them"technical challenges"include having a lower viscosity than diesel, which causes problems with leaks and low efficiency of fuel pressurisation. Like some other biofuels its lower lubricity can cause increased wear on moving parts within the fuel-injection system so it needs a lubricating additive. Its high vapour pressure can cavitate in the fuel injection system too, preventing stable injection,and it is not compatible with certain polymers either.
Yet despite all that,Volvo is adamant that DME has the potential to become a highly competitive alternative to today's fossil fuels. Speaking at the launch of its DME truck last year, AB Volvo boss LeifJohansson declared: "In 20 years, alternative fuels will become increasingly commercially viable. Energy efficiency will become decisive and DME is a truly energy-efficient fuel.A result of this energy efficiency is lower environmental impact and reduced operating costs."
Third-generation DME
Since Johansson made that statement,Volvo has continued to nail its alternative colours to the DME mast. Last month it revealed that it is to develop a third generation of DME vehicles between now and 2010, following the award of a substantial SEK62.2m (f.4.69m) grant from the Swedish Energy Agency -Volvo will match that sum as part of the project.And before the end of the year it will conduct limited field trials with the current secondgeneration DME trucks. However, CA/ understands that up to 30 third-generation DME trucks will participate in field trials during 2009/2010.
In March,AB Volvo acquired 13% of Nissan Diesel (ND). and ND is itself looking at DME. It recently unveiled its own DME truck demonstrator at a conference in the US and claimed that in tests conducted jointly with the US National Traffic Safety and Environment Laboratory it had exceeded the requirements of upcoming 2010 US heavy-duty truck emissions regulations. So will Volvo and ND end up jointly developing a family of DME engines in the future?Time will tell, but right now both companies are clearly treating DME as more than just a passing fad. •
FACT FILE DME has a lower I lubricity than diesel, which can cause extra wear on moving parts