Volvo Powertrain will begin trials with dimethyl ether (DME) fueled trucks in Sweden between late 2009 and early 2010. The trials will involve 14 trucks, with funding from the Swedish Energy Agency and the European 7th Framework Program. Volvo subsidiaries 3P, responsible for product planning, development, and purchasing, and Volvo Technology will also cooperate in the trials.
Volvo Powertrain will rebuild the engines at its Malmö plant in Sweden, modified to operate on the fuel. Volvo has already completed two field trials with DME-fueled vehicles, the first with a bus in 1999 and then with a truck, a Volvo FM9 powered by a 9.0-L, 300-hp (224-kW) engine in 2005. Modifications to the FM9 to enable DME operation included the adoption of a common-rail-type injection system in place of the electronic unit injector (EUI) system favored by Volvo for its diesel engines.
Other modifications included those to the exhaust gas recirculation system and engine control system. Since DME is a gaseous fuel with similarities to liquefied petroleum gas (LPG), Volvo used LPG tanks with a fuel feed system adapted to DME. The vehicle was also fitted with an exhaust oxidation catalyst.
DME is virtually sulfur-free, providing diesel combustion with few particulate emissions. The fuel can be mixed with conventional diesel fuel through a suitably modified fuel system. One of the side effects of the low sulfur content of DME is low lubricity. Part of the Volvo research program is to study the impact on fuel-system components that traditionally rely on the lubricating properties of the fuel.
The engines involved in the trial are based on Volvo’s 13.0-L inline six-cylinder diesel. Once the engines have been rebuilt, the vehicles will begin trials in the Swedish capital Stockholm and the cities of Gothenburg, Piteå, and Växjö. The trials are expected to continue until early 2012. “Today we have both 9.0-L and 13.0-L prototype engines for DME,” said Gert Persson, Project Manager for the local testing in progress at Malmö. “We are presently testing the new fuel system for the 13.0-L engine.”
Commenting on the project, Lars Sundin, General Manager for Volvo Powertrain Malmö, said, “In the plans we are currently making, we will continue to do the application work on the engine in the test cell, and it is also in the plan that we will rebuild the engine from diesel to DME here in Malmö. We will do as much as we can in the lab while the final adjustments for driveability need to be done in the vehicle. It is another fuel, another fuel injection system, and another storage system, but for the driver it should not be any different.”
The trials are part of a wider European program of research into DME produced from biomass, including distribution and DME refueling stations.
Volvo has also announced that the U.S. Department of Energy (DOE) and the Swedish Energy Agency plan to extend their cooperation with the Volvo Group on the development of hybrid technology and drivelines for alternative fuels. The renewed cooperation will last for three years, extending an agreement signed between the three parties in June 2007. The cooperation will take the form of grant funding of $9 million each from the DOE and Swedish Energy Agency, matched by a corresponding amount from the Volvo Group.