New research has discovered that brine production from rocks deep beneath the North Sea could hold the key to unlocking mass carbon dioxide (CO2) storage potential in the UK.

The multi-disciplinary project, funded by the Energy Technologies Institute (ETI) as part of its carbon, capture and storage (CCS) programme, discovered that an eightfold increase in capacity is possible via this method.

The ‘Impact of brine production on aquifer storage’ project studied how controlled brine production could enhance the storage potential of saline aquifers that have already been identified as suitable CO2 stores.

The overall objective was to produce a cost-benefit analysis of brine production using exemplar stores from the CO2-stored database and the UK Storage Appraisal Project (UKSAP).

The project findings also highlight further opportunities in converting smaller aquifers into economically viable stores and lengthening the lifespan of certain storage sites by allowing operators to increase injection rates as new CO2 sources come on-stream.

This development could help reduce the cost of per tonne of tackling the UK’s carbon emissions and help meet the country’s legally-binding carbon targets, according to the research.

Professor Eric Mackay of Heriot-Watt University and principal investigator on the project said that the findings revealed a “host of benefits for developing a CCS industry in the UK” and explained, “We studied a set of potential CO2 stores, identified from the UK’s offshore storage atlas, to assess the value of brine production in terms of both increasing CO2 storage capacity and bringing down the unit cost of storage.”

The project recommends further work that would support the development of CCS in the UK, including an assessment of how much economic value brine production would bring when CO2 stores are handed over to a ‘competent authority’ for longer-term operations and monitoring.

ETI will release its full report on findings later this year.