Natural Gas Trucks Outperform Diesel Models

Natural Gas Trucks Outperform Diesel Models GOLDEN, Colorado, October 30, 2002 (ENS) - A study based on United Parcel Service (UPS) package trucks shows that natural gas fueled vehicles produced just a quarter of the carbon monoxide emissions and half the oxides of nitrogen emissions of their diesel counterparts.

The study was conducted using trucks operated by UPS, which has the nation's largest private compressed natural gas (CNG) fleet. The study compared the operations, maintenance, performance, and emissions characteristics of Connecticut based CNG and diesel vehicles from 1997 to 2000, as part of the broader U.S. Department of Energy/National Renewable Energy Laboratory (DOE/NREL) Truck Evaluation Project.

The CNG trucks ran every working day with no major complaints and were used as much or more than the diesel trucks.

Compared with diesel truck emissions, CNG truck carbon monoxide emissions were 75 percent lower, oxides of nitrogen 49 percent lower, hydrocarbons and non-methane hydrocarbons four percent lower, and carbon dioxide seven percent lower. Total operating costs of CNG trucks were two percent lower than total operating costs of diesel trucks at one of the study sites and 19 percent higher at the other site.

Because the CNG trucks were built with early production technology, they had a 27 to 29 percent lower energy equivalent fuel economy than diesel trucks. Newer technology can reduce this deficit to as low as 10 to 15 percent.

The study results are detailed in 'UPS CNG Truck Fleet: Final Results,' available online at: http://www.ctts.nrel.gov/heavy_vehicle/pdfs/31227.pdf

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Getting methane to burn clean is lot easier than getting long chain hydrocarons to burn clean. I is already a gas and there are no bonds to break. It is ready to burn as is.

There is only one single problem with CNG powered vehicles. Fuel storage and fill up time. For UPS it will work wonderfully. The trucks run all day come back and have all night to fill up. I can be used for any fleet that operates that way.

Dual fuel cars could be made to use CNG for every day driving back and forth to work and use gasoline on the road. So you would have decent fill up times when you were going some where. It would be an intersting engineering problem because the gasoline would have to be used to keep the gasoline system from gumming up and to keep the gasoline in the tank from going bad.

There is also a problem that and engine that can run gasoline can't get maximum effect out of CNG because the compression ratio must be much lower for gasoline.

With fuel injection it would probably be possible to run a car on 90% or 95% methane and 5% gasoline and keep the gasoline system from gumming up and the fuel fresh. But the problem of compression ratios are more difficult. Using propane the power loss is not so bad when you switch to propane that is very noticeable but with methane it would be.

Possibly using gasoline when you needed power in acceleration and methane to cruise would solve all problems.

Methane will work fine as long has you have long enough to fill up.