Scientists Find Way to Extract Methane from Permafrost in 'Double Dividend' in Environmental Safety

Scientists have devised a new way of extracting methane gas from permafrost gas-hydrates. They say the discovery could increase the amount of methane recovered from these sites, while reducing the amount of greenhouse gas released into the atmosphere from other fuel combustion processes—in effect, making the process "more environmentally friendly."

Gas hydrates are ice-like substances formed from water and gas, frequently methane. One of the problems facing energy companies expanding into the Arctic is the formation of gas hydrates in frozen rock mass, which can trigger spontaneous methane emissions.

An international team of researchers from Skoltech University in Russia and Heriot-Watt University in Scotland found that replacing the methane in these hydrates with flue gas generated during fuel combustion was more efficient than current methods of recovering methane. The results were published in Scientific Reports.

The process has an added benefit in that flue gas contains greenhouse gas, so by locking it in permafrost, scientists may be able to reduce the amount released into the atmosphere while preventing the spontaneous release of methane. This makes gas hydrates a potential carbon sink, they say.

"Our approach not only helps extract methane and prevent its free release into the atmosphere but also reduces carbon dioxide emissions," Evgeny Chuvilin, a leading research scientist at the Skoltech Center for Hydrocarbon Recovery (CHR), said in a statement. "I would say our method offers a double dividend in terms of environmental safety."

Flue gas consists of multiple gases produced in coal-powered plants, metal refineries and other furnaces and generated by fuel combustion. On top of carbon dioxide, it contains a mixture of carbon monoxide, nitrogen, sulfur dioxide and water vapour.

By maintaining certain thermodynamic conditions (including pressure and temperature), the team found they were able to use a hydrate formed by the carbon dioxide in the flue gas to replace the naturally-occurring methane hydrate. In total, the method allowed them to capture close to 82 percent of the carbon dioxide contained in the flue gas.

"In comparison with potential methods such as thermal stimulation, depressurization, chemical inhibitor injection, CO2, or CO2-mixed gases (e.g., flue gas) injection is more environmentally friendly because of the potential to capture CO2 simultaneously with methane recovery," the paper's authors say.

Russia is seeking to rapidly expand oil and gas development in its Arctic regions, reportedly offering hefty tax cuts to energy companies willing to extract fossil fuels from its recently discovered reserves—ironically thanks to new routes opened up due to melting sea ice.

Russian gas field
A view of the Bovanenkovo gas field on the Yamal peninsula in the Arctic circle on May 21, 2019. As Russia looks to expand energy exploitation in the Arctic, scientists describe a more environmentally friendly method of extracting methane. ALEXANDER NEMENOV/AFP/Getty