The dawn of the gas age has made GTL an interesting prospect for those seeking to profit from the age of expensive oil. Technology Review has a look at a new technique for turning natural gas into liquid fuel - Chasing the Dream of Half-Price Gasoline from Natural Gas.
At a pilot plant in Menlo Park, California, a technician pours white pellets into a steel tube and then taps it with a wrench to make sure they settle together. He closes the tube, and oxygen and methane—the main ingredient of natural gas—flow in. Seconds later, water and ethylene, the world’s largest commodity chemical, flow out. Another simple step converts the ethylene into gasoline.
The white pellets are a catalyst developed by the Silicon Valley startup Siluria, which has raised $63.5 million in venture capital. If the catalysts work as well in a large, commercial scale plant as they do in tests, Siluria says, the company could produce gasoline from natural gas at about half the cost of making it from crude oil—at least at today’s cheap natural-gas prices.
If Siluria really can make cheap gasoline from natural gas it will have achieved something that has eluded the world’s top chemists and oil and gas companies for decades. Indeed, finding an inexpensive and direct way to upgrade natural gas into more valuable and useful chemicals and fuels could finally mean a cheap replacement for petroleum.
Natural gas burns much more cleanly than oil—power plants that burn oil emit 50 percent more carbon dioxide than natural gas ones. It also is between two and six times more abundant than oil, and its price has fallen dramatically now that technologies like fracking and horizontal drilling have led to a surge of production from unconventional sources like the Marcellus Shale. While oil costs around $100 a barrel, natural gas sells in the U.S. for the equivalent of $20 a barrel.
But until now oil has maintained a crucial advantage: natural gas is much more difficult to convert into chemicals such as those used to make plastics. And it is relatively expensive to convert natural gas into liquid fuels such as gasoline. It cost Shell $19 billion to build a massive 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.