A POTENTIAL game changer in the race to perfect carbon capture and storage systems is being developed by Scottish and Chinese scientists.

Scientists from Edinburgh University have joined with colleagues in China in a new development that could enable large-scale storage of carbon dioxide emissions in rocks underneath one of China’s most industrialised and polluted provinces, Quangdong.

A team from the university has been studying geology deep below the Pearl River Mouth basin. Formerly known as the Canton River, the Pearl River is the third longest river in China and empties through a vast delta into the South China Sea between Hong Kong and Macau.

The joint group’s findings will help to develop its suitability as a site for carbon storage, in which quantities of the greenhouse gas are injected and contained in rocks deep underground.

According to a statement from Edinburgh University: “The area has vast capacity for storing CO2 but a limited ability to provide a long-term mechanism to seal the gas into the rocks.

“Researchers suggest that a concept known as dispersion trapping could support long-term storage by securing the injected CO2 within the site’s geology. Such a development could pave the way to tackling the region’s significant carbon emissions.”

The geoscientists’ work, which focused on three depleted oil fields in the Huizhou area, could unlock decades of secure CO2 storage offshore for projects, such as the Haifeng full-chain offshore Carbon Capture, Utilisation and Storage (CCUS) project at a coal-fired power station.

Their research, published in the International Journal of Greenhouse Gas Control, has been supported by the Scottish Funding Council, EPSRC and NERC.

It was carried out under the partnership of Scottish Carbon Capture and Storage (SCCS), which includes British Geological Survey, Heriot-Watt University and the universities of Aberdeen, Edinburgh and Strathclyde.

China continues to be the world’s largest emitter of CO2 due to a dependence on coal as a source of energy.

Carbon capture and storage could play a crucial role in reducing the country’s greenhouse gas emissions and helping it meet its commitment to the Paris Agreement.

Dr Niklas Heinnemann of Edinburgh University’s School of GeoSciences said: “The Pearl River Mouth Basin reservoirs have excellent storage potential but we need to ensure that they provide long-term containment of CO2.”

His Edinburgh colleague Professor Stuart Haszeldine, also of the School of GeoSciences commented: “We’ve suggested an alternative method of developing this resource into secure stores using dispersion trapping. “It’s a bit like having a damp sponge of CO2 spread throughout the rock. None of the CO2 can escape, even though there is no single seal.

“All the pore space can be used if injection is planned differently to disperse CO2 widely at many levels within the geology. This is like creating direct entrances into several floors of a residential tower block, rather than just using one floor. The work is applicable to many reservoirs in China, and globally.”