Natural Gas Vehicles (NGV) - Are They Cheaper in the Long Run ? By Dr. Joseph S. Maresca
Natural gas derives from the decay of ancient organisms. It naturally takes a gaseous form . Natural gas occurs often in association with crude oil. It is derived from both land plants and aquatic organic matter and forms above or below oil deposits.
The biggest advantage of NGVs is that they reduce harmful emissions in the environment. Natural-gas vehicles can achieve up to a 90 percent reduction or more in carbon monoxide emissions. 1)
A brand-new natural-gas vehicle costs about $5000 more than a comparable gas vehicle. It's also possible to modify conventional gasoline vehicles to run on natural gas. This, too, can be expensive, with the modifications typically costing about $4,000 . NGVs are safer. The fuel storage tanks on a NGV are more dense and the material is stronger than gas or diesel tanks.
Natural gas costs are lower than gas costs. On average, natural gas costs about one-third less than gasoline at your neighborhood station . Natural gas is convenient and generally available. A well-established pipeline infrastructure exists in the United States to deliver natural gas to almost every metropolitan area and most suburban ones . There are 1,500 or more NGV fueling stations in the United States, with more being added . The price of NG is stable and about 1/3 less than gasoline. This stability makes it easier to plan accurately for long-term costs.
NGVs have lower maintenance costs. Natural gas burns cleanly and cheaply relative to the gas engine . NGVs result in less wear and tear on the engine . The time between oil changes and major tune-ups is extended.
NGVs aren't as roomy as gasoline cars. This is due to NGVs having to give up cargo and trunk space to accommodate the fuel storage cylinders. There is a limited driving range of NGVs. This is typically about half the range of a gasoline-powered vehicle.
While natural gas reserves in the United States are still considerable, they are not inexhaustible. Some predict that there are enough natural gas reserves remaining to last another 70 or more years . We can extend this reservoir by importing natural gas , exploring NG in outer space in places like Saturn or improving NG mileage efficiency through engineering research.
Saturn's orange moon Titan has hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth. ( NASA's Cassini spacecraft) The hydrocarbons literally rain from the sky. Vast deposits are collected in lakes and dune formations. Practically speaking, commercialization is decades away. Nonetheless, Saturn's Titan has the potential to become a permanent game changer later this century and thereafter.
"Titan is just covered in carbon-bearing material, it's a giant factory of organic chemicals," says Ralph Lorenz, Cassini radar team member from the Johns Hopkins University Applied Physics Lab . "This vast carbon inventory is an important window into the geology and climate history of Titan."
U.S. natural gas proven reserves, estimated as "wet" gas includes natural gas plant liquids, which increased by 11% in 2009 to 284 trillion cubic feet (Tcf), the highest level since 1971. Major improvements in shale gas exploration and production technologies drove the increase in U.S. natural gas proven reserves. 2)
Two prominent car companies in NGV design and engineering are Honda and DaimlerChrysler. Many long-haul trucks and buses run on a different form of natural gas called liquefied natural gas, or LNG. LNG is made by refrigerating natural gas to -260°F, condensing it into a liquid. The liquid form is denser and thus has more potential energy for the amount of space taken up. This translates into more energy which can be stored in the same amount of space as a car or truck. LNG can be dangerous. There is no odorant in the gas requiring sensors for leak detection. Generally, when sensors detect a leak, the vehicle shuts off immediately. LPG (liquid propane gas) may be the way to go. There is better mileage and fueling stations are plentiful. Many farms used dual fuel trucks. A switch is flipped to power the vehicle from gasoline to propane.
Both Ford and GM make natural gas (NG) powered vehicles, they just don’t sell them here in the U.S. The technology is well established. The problem is a lack of refueling locations. Since we already have a great distribution network for natural gas it should not be too difficult to establish such refueling stations. Heck, it might even be possible to sell the gear to individuals to refuel NG powered cars at home. In fact, most people already have NG service for home heating. Making such devices small, cheap and safe enough for home garage use might take a little doing, but U.S. industry should be up to that engineering challenge. However, gas stations are not going to start installing NG refueling systems while there are few if any NG vehicles on the road. People are not going to start buying large numbers of NG powered cars if there is nowhere to fill up.
The benefits of moving that direction though would be huge. At current prices, NG is selling for the equivalent of just $22.86 a barrel, or less than a quarter of the price of oil. While if NG powered vehicles became common, it is likely the price of NG would move up, that is still a huge gap to fill. The gap could also be filled the other way, as lower U.S. demand for oil results in lower oil prices (more likely a combination of the two). 3)
Natural gas vehicles are bi-fueled autos with a spark ignition petrol engine. The NG is also employed in the standard compression ignition engines for larger vehicles or even trucks. Engine technologies which run on NG include: a) stoichiometric combustion b) lean burn c) single point injection d) the multi-point injection
Natural gas is stored on board as either compressed natural gas or liquified natural gas. The gas is stored in pressurized bar cylinders located in the boot space of the auto. Compared to petrol, NG autos offer a CO emissions reduction of 90% or more with 25% less CO2 and 35-60% less NO emissions (nitric oxide ) and 50-75% reduced non-methane hydrocarbon emissions. There are fewer toxic and carcinogenic pollutants. 4) The temperature could be lowered using gas-mixing techniques, to stop the NO formation. One technique being explored, already employed in spark-ignition gasoline engines, is to recirculate exhaust gas into the cylinder, where it absorbs some of the heat and lowers the combustion temperature. (diesel combustion )
Urban buses are one of the growth areas for NG vehicles. NG vehicle growth is highest in Asia where there are large and growing populations.