Scientists from Scotland and Russia claim to have identified a new method of extracting Methane Hydrate, a potentially revolutionary energy source, but one which offers challenges to those hoping to capitalise on it's potential.
The methane hydrate is found primarily on the edge of continental shelves typically 500 metres below the water, contained within permafrost where it presents as ice crystals with the gas trapped inside.
According to some reports, the methane gas within the hydrate could be the next significant energy source with studies suggesting there is more energy in the methane hydrates than in the world's oil, coal and gas put together.
Therefore, it is unsurprising that countries worldwide are looking for methods to extract the gas with scientists at the University of Southampton finding indicators of the gas at several European sites. UoS Professor, Tim Minshull, said:
"We found the gas hydrate is particularly widespread around Svalbard, off Norway and the black sea, but the hydrate systems have only been well investigated in a few areas, so there could be much still to discover."
Unfortunately, extraction has proved difficult due to the specificity of the conditions required for hydrates to form. These conditions are affected by several factors including pressure, temperature and the stability of surrounding liquid and gas compositions for extraction. Further to conditional challenges, the process also presents environmental and technical issues.
Japanese scientists were among the first to begin trials with methane hydrates, to reduce their reliance on imported energy. However, early tests in 2013 were abandoned due to mechanical issues caused by sand getting into their machines.
In 2017, further Hydrate tests were conducted by Japan and China, which resulted in small breakthroughs, but experts fear mass availability remains many years away.
There are also several environmental challenges related to the current extraction process, which lowers the gas pressure, potentially de-stabilising the seabed. This destabilisation and water release from the methane also increases the risk of landslides and, as a consequence, may create Tsunamis.
However, Scientists from a joint-project between Heriot-Watt University in Scotland and Skoltech Centre for Hydrocarbon Recovery in Russia have developed a new method which, they say, could reduce the environmental concerns and increase the amount of methane gas extracted.
Leading research scientist at the Skoltech Centre for Hydrocarbon Recovery (CHR), Evgeny Chuvilin, said:
"Our approach not only helps extract methane and prevent its free release into the atmosphere but reduces carbon dioxide emissions. I would say our method offers a double dividend in terms of environmental safety."
The method was tested to find the optimum pressure for extracting the gas, and the process involves injecting flue gas, created by fuel combustion, into the permafrost areas to form a new hydrate – the flue gas contains carbon dioxide which means it is contributing to the reduction of greenhouse gases in the arctic atmosphere as well as helping extract the methane gas.
They use waste gases to make the flue gas with the primary sources coming from coal-burning plants, metal refineries and other industrial plants.
The team found that by maintaining the necessary conditions, they were able to use carbon dioxide in the flue gas to replace the methane hydrate and form the hydrate.
As well as the challenges, harvesting Methane Hydrates also presents the industry with an opportunity; to capitalise on this new natural gas and reduce its potential for devastation as a result of climate change. Studies suggest that methane gas is 30 times more damaging to the environment than carbon dioxide, therefore, as oceans continue to warm, the risk of an uncontrolled natural release of seabed gasses to surface becomes an increasing reality. Extracting the methane is one way of proactively controlling this threat – if we can balance the risks caused by its extraction.