Natural gas is a widely used, relatively clean, and readily available fuel. It is all around us, heating our homes, generating electricity, and being used in everything from the manufacture of chemical fertilizer to plastic. All said, it is “our second most important energy source after oil” (Darley 2005). But despite its many advantages as a transportation fuel, natural gas has largely failed to develop a strong niche in motor vehicle production. Though it has been used to fuel cars for decades, and today remains among the relatively cheap alternatives to petroleum, the low number of natural gas vehicles in production seems to suggest that it will never displace the percentage of standard gasoline engines of which it is capable. Yet, natural gas reserves could serve as a bridge to future energy technologies.

The History of Clean, Reliable Natural Gas

Not surprisingly, early human encounters with natural gas likely date to ancient Mesopotamia, or the cradle of civilization that is known today as the Middle East. Historical and biblical references to humankind's encounters with natural gas include burning springs created when something, perhaps lightening, ignited natural gas seeping out from the earth. Early cultures and religions often attributed such phenomena to divine origins and built shrines at the sites for worship, where flares remained burning sometimes for centuries (Ingersoll 1996).

Some posit that the Chinese may have recognized the energy potential for natural gas as early as 900 B.C., but their first known natural gas well was drilled in 211 B.C. In later centuries, the Chinese adapted bamboo pipelines to transport it to provide fuel for boiling water, heating, and the first known instances of lighting. The Japanese dug gas wells as early as A.D. 615. More recently, by 1626, French explorers observed indigenous people in North America igniting seeping gases near Lake Erie. Meanwhile, natural gas manufactured as a byproduct of coal began lighting houses and streetlights in Great Britain by the late eighteenth century. In 1816, this same technology was first implemented in the U.S. in Baltimore, but William Hart—sometimes deemed the father of natural gas in America—dug the first shallow well to extract naturally occurring natural gas in 1821 (Speight 2007).

Originating beneath the earth’s surface in geological formations, natural gas can be obtained in many ways, often as an associated product of petroleum (Ingersoll 1996). Indeed, various methods of processing natural gas from crude oil have been used since the middle of the nineteenth century, but reliable pipelines were in short supply and most was simply flared off or, worse, released into the atmosphere. Still, when Edwin Drake struck oil in Pennsylvania in 1859, it wasn't long before localized short-distance transmission allowed for industrial uses of the initially undesirable natural gas by-product. In 1872, a five-mile, two-inch iron pipeline transmitted the first recorded natural gas from the site of Drake's oil discovery in Titusville to Newton, Pennsylvania. By 1891, a line longer than one hundred miles connected Chicago to Indiana gas fields. At the turn of the century, natural gas continued to be used primarily for lighting.

As reliable welding and leak-proof pipe coupling technology developed in the early twentieth century, the pipeline network began to grow, showcasing the first relatively long-distance lines among major eastern cities in the United States. But natural gas usage shifted when manufacturers began conditioning natural gas by removing "drip gasoline, or…casing head gasoline, which provided the origins of the modern gas processing industry" (Speight 2007). Only after World War II did natural gas truly find its niche, as products and applications for it increased along with the supply network, beginning with the industrial sector. Along with the production of natural gas liquids, major natural gas-producing countries including the United States, Canada, Russia, Iran, Indonesia, and Norway pursued natural gas production for its improved environmental qualities. But since transportation costs are high, most natural gas produced is either used only domestically or piped into adjacent countries.

As natural gas was taken up for commercial and residential applications, stringent standards of cleanliness were developed and the natural gas industry became strictly regulated. Like crude petroleum products, natural gas undergoes processing and refining to strip the wellhead natural gas product down to the cleaner-burning, purified methane. The materials—particularly associated hydrocarbon liquids such as ethane, propane, and butane—are removed from natural gas so it can be safely transported and processed (including liquefaction and compression) and used in natural gas applications, from heating houses and businesses to propelling motorized vehicles (Speight 2007). Natural gas vehicles (NGVs), in particular, have been in the spotlight in recent years as governments and automakers have sought alternative fuel possibilities to power the ever-increasing demand for vehicles with less of an environmental impact.

The Possibility of Natural Gas-Powered Vehicles

While the nascent automobile industry showed great promise around the turn of the century, large crude oil fields had been discovered under the United States and the Middle East. Largely as a consequence of having unearthed this vast supply of cheap, readily available fuel, the oil and automotive industries would become inseparable. Had crude oil (petroleum fuels such as gasoline and diesel) not become the standard, what are now commonly referred to as “alternative fuels” (including ethanol and biodiesel) may have been the fuel of choice for the automotive industry (as, indeed, ethanol was in the earliest days, due to its being derived from widely available fermented sugars and starches). Instead, they are relegated (and officially categorized) to small-niche production, even as the price of crude oil has risen (Ingersoll 1996).

Today, while many alternative fuels are expensive and intensive to manufacture or are otherwise in short supply, one widely available alternative fuel for vehicles (though also a nonrenewable fossil fuel) is natural gas, which has been used for transportation energy needs for decades. But the fuel first gained added attention as a result of the energy crisis and oil shortages of the late 1960s and early 1970s, and as a feedstock or bridge to future technologies.

Moments in the History of NGVs

Actually, as far back as the 1930s, natural gas and manufactured gas were used in motor vehicles, though crude oil expansion after World War II drove its use down. But “natural gas vehicles never disappeared from the roads of America” (Ingersoll 1996). Natural gas-powered vehicles are functionally similar to a standard gasoline engine. For this reason, after-market conversions, though costly, can be performed on standard engines, allowing for vehicles to run either solely on natural gas or as a bi-fuel vehicle, running on both natural gas and petroleum. Most NGVs use space-saving compressed natural gas (CNG) which is stored in fiberglass-protected, composite-metal storage tanks that have evolved over the years into smaller, lighter-weight—yet safer—models, both for original model NGVs and after-market conversions (ngvamerica.org).

Once the United States emerged not only through the oil shocks of the 60s and 70s (and also the Cold War), rather than developing new energy programs focusing on constraint and alternative sources, Americans pursued standards of production and consumption with renewed vigor. The result is that America continually imports more oil than ever which, some experts have long believed, not only contributes negatively to the global environment but has also been instrumental in the current economic issues and the threat of further trouble. Indeed, in the late 1980s, the United States government was still only evaluating natural gas as a viable alternative fuel. Yet the same concerns about energy dependence that plague the government today were deeply troubling throughout the past decades as more than half of the oil used domestically was now being imported (Darley 2005).

Even in 1993, on the heels of the Gulf War, the revised Clean Air Act of 1990 and the Energy Policy Act of 1992, which could have put millions of natural gas-powered vehicles (or other alternative fuel vehicles) on the roads, U.S. automakers stalled over legitimate concerns over profitability and consumer interest. One provision of the Clean Air Act that has pushed the move to cleaner fuels includes the fuel pilot car program for California that has caused the gradual phase in of increasingly tighter emissions standards—standards which have forced American automakers to keep pace with automakers from around the world in fuel and emissions standards. California still leads the nation in emissions standards and the availability of cleaner vehicles. Meanwhile, the Energy Policy Act pushed for governmental fleet vehicle mandates that have driven a dramatic increase in the number of cleaner or alternative-fuel cars used by city, state, and federal agencies (Cannon 1993).

Moving Forward

Today, nearly nine million NGVs are in use throughout the world, with roughly 130,000 in use in the United States that fill up at some 1,200 natural gas fueling stations—but the more than 140 million registered cars in the U.S. means standard vehicles outnumber natural gas vehicles more than 1000 to 1. Though in only a fraction of the total vehicles on the road, natural gas is used in everything from passenger cars to heavy-duty trucks and forklifts to commercial fleets, taxies, and buses.

Since natural gas contains less carbon than other transportation fossil fuels, “NGVs produce up to 20 percent less greenhouse gas emissions than comparable gasoline vehicles and up to 15 percent less than comparable diesel vehicles”—and that’s just in carbon dioxide (ngvamerica.org). Other emissions are reduced by even greater percentages, fuel evaporation during refueling is significantly less, and the very process of natural gas production is “less polluting than producing and refining oil or generating electricity at coal-burning power plants” (Cannon 1993).

Moreover, since natural gas has a higher ignition range and smaller range of flammability, it is considered generally safer than gasoline. Perhaps most importantly, “natural gas is not toxic or corrosive and will not contaminate ground water” (ngvamerica.org).

Yet in spite of its potential to displace at least a portion of America’s petroleum dependency, natural gas does not seem to be catching on among consumers in the United States. In recent years, Ford and GM have pulled out of natural gas, focusing instead on hybrids and related technologies. Honda and Daimler continue to design and engineer NGVs, perhaps most notably Honda’s Civic GX sedan (in production since 1998), which is now also available with a “slow-fill” (overnight) home refueling device (Woodyard 2007).

There has been much talk about the future of alternative fuel vehicles, particularly in the United States, whose modern energy crisis has sparked renewed interest in the pursuit of new technologies for energy independence. Natural gas may play a significant role in America’s energy future. Not only does 97 percent of the natural gas used in the United States come from North America (85 percent U.S. and 12 percent Canadian), but the Natural Gas Supply Association says there is at least a 60-year reserve available. But it is not that natural gas could ever replace standard gasoline engines—it can only stand in for a percentage, perhaps as much as 20-30 percent, and only for a time (Woodyard 2007).

Perhaps most interestingly, natural gas currently plays a key role in other future alternative energies, from CNG-powered plug-in hybrids to fuel cells to hydrogen. Presently, natural gas is the largest feedstock for natural gas production, which means that most of the hydrogen used to fill hydrogen-powered vehicles hitting the market is a byproduct of natural gas. Incidentally, though natural gas is a nonrenewable resource, its primary component, methane, can be derived from biomass such as sewage and landfills.

While it is possible that technologies will be developed to better acquire hydrogen from other, renewable sources, the Natural Gas Vehicles for America organization points out that the next era of alternative fuels is being jumpstarted by natural gas. Natural gas “presents a compelling continuum towards sustainable energy systems in American” by bridging the gap between existing technology and future technology, and by helping people develop the tools for working with the technology. Natural gas technology is establishing new infrastructures for fueling, including home refueling, and advocates are developing campaigns to encourage broader acceptance of new technologies and for training people to prepare for them (ngvamerica.org).

-- Posted September 8, 2008

References

"About Natural Gas Vehicles." NGVAmerica.org. 2006. Accessed: August 15, 2008.

Cannon, James S. 1993. Paving the Way to Natural Gas Vehicles. New York, NY: Inform, Inc.

Darley, Julian. 2005. High Noon for Natural Gas: The New Energy Crisis. White River Junction, VT: Chelsea Green Publishing Company.

Ingersoll, John G. 1996. Natural Gas Vehicles. Lilburn, GA: Fairmont Press, Inc.

Péralte, Paul C. "Plastics get pricier, forcing companies to revamp." Atlanta-Journal Constitution. June 21, 2008. Accessed: August 23, 2008.

Speight, James G. 2007. Natural Gas: A Basic Handbook. Houston, TX: Gulf Publishing Co.