The effort to make natural gas a more efficient fuel for powering long-haul freight trucks has increased with the introduction of a new model by Volvo Trucks, a division of Sweden's AB Volvo. The company officially revealed a production-line ready, heavy-duty model that runs on a mixture of 75% liquefied natural gas (LNG) and 25% diesel fuel. The model will be available only in Europe at this point.

The interesting twist to Volvo's new FM MethaneDiesel model is that it can use either LNG or biogas, refined from such things as methane vapors generated from landfill decomposition, as the main ingredient in its fuel cocktail, the company said. That's because both natural gas and biogas share methane as the “base stock” in their composition, noted Lars Martensson, director-environmental affairs for Volvo Trucks.

He said that Volvo uses a conventional 13L diesel engine generating 460 hp. and roughly 1,696 lbs.-ft. of torque. It's equipped with gas injectors, a special fuel tank that keeps the gas liquefied and chilled to roughly -284 deg. F, plus a specially modified catalytic converter so it can operate on blended methane/diesel fuel.

If the natural gas tank runs dry, Volvo said the system automatically switches over to diesel, with the driver alerted via a control lamp that comes on in the instrument panel.

“By using liquefied gas, more fuel can be stored in the tanks compared to if the fuel is compressed,” Martensson said. “This gives the methane-diesel truck a far greater range than that of traditional gas-powered trucks that utilize spark-plug technology.”

Thus, in a truck with a gross weight of 40 tons, the fuel tank holds enough gas for a range of about 310 mi. in normal driving. In the U.S., the average length of haul is between 400 and 500 mi. In Europe, however, a truck that covers 310 mi. on a single tank of fuel is more than adequate, particularly when it makes natural gas a more efficient option than before, noted Claes Nilsson, president of the Europe Division at Volvo Trucks.

“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,” he said.

Compared with conventional natural gas-powered spark-plug engines, Volvo's natural gas technology offers 30 to 40% higher efficiency, which in turn cuts fuel consumption by 25%, according to Nilsson.

Since the price of natural gas is often significantly lower than that of diesel, financial savings are also possible, he added, and such savings are a “necessary precondition” for widespread acceptance of new technology.

“In the U.S. and parts of Asia, Europe and South America, [natural] gas power is either already in use or decisions have been taken to invest in this power source,” Martensson said. “Thailand, for instance, is well to the fore with an established infrastructure and good availability.”

Initially, Volvo plans to sell the FM MethaneDiesel just in Europe, starting in the Netherlands, Great Britain and Sweden, where natural gas infrastructure is best established, Nilsson said, with other parts of the world following.

“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,” Nilsson stated. “Future sales will naturally depend largely on expansion of liquefied gas filling stations for commercial vehicles.”