Liquefied gas is the alternative fuel of choice for a new regional distribution truck from Volvo Trucks that can also fulfill long-haul requirements. The Volvo FM MethaneDiesel, which will launch initially in select European countries where sufficient infrastructure exists, can run on a fuel combination of up to 75% natural gas or biogas—both of which consist of methane—and the rest diesel. The proportions can vary depending on how the vehicle is used.
“The sales start of our methane-diesel model creates new conditions for the gas truck market. By using liquefied gas in an efficient diesel engine, we make it possible to use gas-powered trucks in heavier and longer-distance transport operations, making us the first manufacturer in Europe to do so,” claims Claes Nilsson, President Europe Division at Volvo Trucks.
The new FM MethaneDiesel model is powered by a 13-L engine producing 460 hp (343 kW) and 2300 N·m (1700 lb·ft) of torque. The technology is based on a conventional diesel engine equipped with gas injectors, a “Thermos-like” fuel tank that keeps the gas liquefied and chilled to -140°C (-220°F), and a specially modified catalytic converter.
Using liquefied gas allows more fuel to be stored in the tanks than if the fuel is compressed, providing greater range than that of traditional gas-powered trucks that utilize spark-plug technology, according to the manufacturer. In a truck with a gross weight of 40 t (44 ton), the fuel tank holds enough gas for a range of up to 500 km (310 mi) in normal driving.
“It’s the same diesel base engine, but we’ve added a so-called sandwich plate with all the gas injectors, which is positioned between the air inlet manifold and the engine itself,” explained Mats Franzén, Manager Engine Strategy at Volvo Trucks. “Also, in the aftertreatment system we have added a methane catalyst to take care of any methane slip. It is the normal diesel engine with those small changes.”
(Click here to view an animation of the methane-diesel technology.)
Volvo Trucks’ field tests show that the methane-diesel engine offers the same operating reliability as the conventional diesel, and with “similar” driveability, Franzén said. When the gas tank runs dry, the system automatically switches over to diesel. The driver is alerted via a control lamp that comes on in the instrument panel.
This technology with natural gas generates 10% lower CO2 emissions than a diesel engine does, according to Volvo Trucks. In the long term, the truck maker regards the increased use of natural gas as a major step toward greater availability and use of biogas, which further reduces CO2 emissions.
“We are convinced that liquefied gas is one of the most important future alternatives to today’s vehicle fuels,” said Lars Mårtensson, Director Environmental Affairs at Volvo Trucks.
The company claims that, compared with conventional gas-powered spark-plug engines, its gas technology offers 30 to 40% higher efficiency, which in turn cuts fuel consumption by 25%.
“Interest [in natural gas] is being largely driven by environmental considerations as well as by concerns over the secure supply of energy,” said Mårtensson. “In the U.S. and parts of Asia, Europe, and South America, gas power is either already in use or decisions have been taken to invest in this power source. Thailand, for instance, is well to the fore with an established infrastructure and good availability.”
The Volvo FM MethaneDiesel will be sold initially in the Netherlands, the U.K., and Sweden. Current plans call for about 100 trucks to be built in 2011, with series production beginning in August. The truck will be offered in other parts of Europe and the world in the future, infrastructure-permitting.
“If things go as planned, we expect sales to take off in six to eight European countries within the next two years, with about 400 Volvo FM MethaneDiesel trucks sold a year,” said Nilsson. “Future sales will naturally depend largely on expansion of liquefied gas filling stations for commercial vehicles.”
Nilsson acknowledges that diesel will remain the dominant fuel for “many years to come” but believes that “methane will become a fairly good substitute to diesel, [following] a fairly slow ramp-up and over time taking part of the diesel volume.”