Diesel’s main contenders: Natural gas series, Part 3

Natural gas holds the most promise for heavy-duty applications, but other alternative fuels are finding trucking niches:

Natural gas

Natural gas certainly supports fleets that want to embrace domestic energy sources. President Obama recently described the United States as the “Saudi Arabia” of natural gas. Available supplies also are expanding because of hydraulic fracturing techniques that are tapping into once-ignored pockets of the fuel trapped in layers of shale.

Shell is predicting that LNG and diesel are going to be the fuels of choice for commercial vehicles as far into the future as 2050. “It’s abundant, affordable and [environmentally] acceptable,” says James Burns, general manager of Shell’s LNG transportation network in the Americas.

Shell recently announced plans to sell LNG through TravelCenters of America facilities. The proposed plans include constructing more than 200 LNG fuel lanes at about 100 TA sites and Petro Stopping Centers. If a final agreement is reached, the first fuel lanes would become operational in 2013.

Natural gas needs to be prepared in different ways to make it a suitable vehicle fuel. Since it holds less energy by volume than diesel, it has to be compressed or liquefied, reducing the required storage space and increasing driving range.

Even then, there still are gaps. A diesel truck that enjoys 6.5 mpg of diesel might deliver 3.8 mpg on LNG and 1.7 mpg on CNG, Burns says. To travel 100 miles, the same truck would need 15 gallons of diesel, 28 gallons of LNG or 58 gallons of CNG stored at 3,600 psi.