The United States has found itself with an abundance of natural gas thanks in large part to a boom in shale fracking and horizontal drilling. But turning the raw gas into something usable remains a real challenge.
The good news: practically anything that can be made from petroleum, whether fuel or chemical, can theoretically also be made from natural gas.
Natural gas is much clearer than oil— power plants that burn oil emit 50 percent more carbon dioxide than natural gas ones—and its domestic abundance makes it a thrifty and predictable alternative to importing foreign oil.
In fact, the U.S. Energy Information Administration (EIA) predicts there is enough natural gas underground to last America for 92 years.
The bad news: scientists are still struggling to figure out how to convert natural gas into a viable energy source that can compete on equal footing with petroleum and coal.
Cost is a huge factor
According to a recent article in the MIT Technology Review, it cost Shell $19 billion to build a gas-to-liquids plant in Qatar, where natural gas is almost free. The South African energy and chemicals company Sasol is considering a gas-to-liquids plant in Louisiana that it says will cost between $11 billion and $14 billion.
Altogether, such plants produce only about 400,000 barrels of liquid fuels and chemicals a day, which is less than half of 1 percent of the 90 million barrels of oil produced daily around the world.
“Current technologies to convert natural gas into fuels or commodity chemicals are too expensive to compete with products generated from petroleum,” says Roy Periana, director of the Scripps Energy and Materials Center at the Scripps Research Institute in Florida.
Periana and his team are working on a new way to convert natural gas into usable energy like gasoline, diesel fuel, alcohols, and olefins.
Processing raw gas is so expensive because the carbon and hydrogen atoms that make up its composition are extremely strong—the strongest known to chemistry in fact. Refining them requires super-high heats (1,650 degrees Fahrenheit or 900 degrees Celsius) and intricate techniques.
Periana and his team think they may have found a solution: a new conversion process which uses lower temperatures of about 400 degrees Fahrenheit (200 degrees Celsius) and fewer steps. The team is using inexpensive ordinary metals like thallium and lead rather than costly precious metals like platinum, palladium, rhodium or gold, as catalysts.
Periana says this new process—which is explained in the March issue of Science—will be ready for commercialization within the next three to four years.
Siluria, a California-based startup, claims it’s also on the cusp of a solution. The company says it can produce gasoline from natural gas at about half the cost of making it from crude oil. To achieve this, Siluria has developed a way to rapidly screen potential catalysts and manipulate their composition and structure for the most efficient conversion process.
Siluria says the catalysts produced at its pilot plant in Menlo Park, California, have performed well enough to justify building two larger demonstration plants—one in San Francisco Bay that will make gasoline, and one in Houston that will make ethylene.
The company hopes to prove that the technology will work at a commercial-scale and can be plugged into existing refineries and chemical plants.
Fossil fuels by the numbers
Today, according to the EIA, 36.7 percent of U.S. energy supply comes from petroleum, followed by 25.2 percent from natural gas, and 21.3 percent from coal. Only 8.2 percent comes from renewable energy and the remaining is nuclear generated.
The transportation and industrial sectors demand the most energy – almost 50 percent of all that’s consumed.
The EIA predicts that by 2035, 46 percent of America’s natural gas supply will come from shale gas.
As shale gas production increases so the import of liquid fuels will decline. Biofuels and greater fuel efficiency will also contribute to the decline in imports. The EIA predicts that liquid biofuels and renewable energy sources will see significant uptick in the next 15 to 20 years.
The electric-power sector and industry will be the biggest consumers of natural gas energy in the coming decades, driven by a 23 percent growth in electricity consumption over the next 15 years.
Today, the transportation sector is one of the biggest consumers of natural gas. In Latin America, Europe and North America high fuel prices and environmental concerns have led to natural-gas options for pickup trucks, commercial vehicles and public transportation.
The natural-gas market in the U.S. has been primarily transit buses – over 10,000 are currently in use. Elsewhere in the world the numbers are much higher.
Over 25 automakers produce nearly 100 models of natural-gas vehicles and engines for the U.S. market, but these are mostly fleet vehicles. Natural-gas vehicles for the consumer market remain scarce. Honda is one of the only car manufacturers to venture into the consumer market.
Honda’s 2014 Civic Natural Gas will cost you more than the regular Civic but it will also save you significant money at the pump.
General Motors, Ford, and Chrysler also have heavy-duty pickups converted to run on natural gas. All three are available from dealers upon special order.
Refueling natural-gas cars remains a pain, with only a limited number of stations in the U.S. Home refueling is possible but not recommended because of safety concerns.
An imperfect solution
While the U.S. may be experiencing an abundance of natural gas right now—more than 99 percent of the natural gas used in America today is domestically produced—it won’t last forever.
Increasing demand for natural gas in power plants will eventually require new supplies from non-North American countries, leading to dependence on foreign sources of energy once again.
And the environmental impacts of fracking are well documented. As well as devastating the landscape, natural gas extractions causes a significant release of methane.
Methane is 72 times more powerful than carbon dioxide when it comes to trapping heat, and therefore a more potent factor in climate change.
If those in the fracking industry allow more than 3.2 percent of the methane they produce to escape into the air, then the benefits of switching from coal to natural gas are lost, according to researchers at Princeton University.
Recent studies have indicated that methane’s concentration in the atmosphere is increasing, although it’s difficult to pinpoint the causes.
Biofuels and renewables could be a safer bet in the long run, and recent breakthroughs looks promising.
Do you think natural gas is a viable energy solution for America? Is it sustainable?
Photo: Melanie Stetson Freeman/The Christian Science Monitor via Getty Images
Nancy Pardo contributed to this story.