Enhancing CO2 storage capacity with brine production

May 10 2017

The controlled production of brine from saline aquifers beneath the North Sea can greatly increase the amount of carbon dioxide that can be injected for storage according to research.

A multi-disciplinary project, funded by the Energy Technologies Institute (ETI), has studied how brine production, more often associated with oil and gas operations, can enhance the storage potential of saline aquifers already identified as ideal CO2 stores. 
The project, Impact of brine production on aquifer storage (ETI ref CC2010), was funded by the ETI as part of its CCS programme. The overall objective was to produce a cost-benefit analysis of brine production using exemplar stores from the CO2Stored database and the UK Storage Appraisal Project (UKSAP). A full project report will be made available by the ETI later this year.
The project findings, which will be presented at All-Energy 2017 on 11 May, also highlight other key benefits of using brine production alongside CO2 storage, including the opportunity to convert smaller aquifers into economically viable stores. It may also give certain storage sites a longer lifespan by allowing operators to increase the injection rate at a later date as new CO2 sources come on stream. 
The UK has some of the world’s best geological CO2 storage, up to 2.5km below the North Sea, which can be utilised in carbon capture and storage (CCS) projects to help the UK meet legally binding carbon targets. These storage sites have already been identified by CO2Stored, the UK's offshore storage atlas, which led from the ETI’s UK Storage Appraisal Project.
The project team was led by Scottish Carbon Capture & Storage (SCCS) partner, Heriot-Watt University, and included researchers from energy consultancy, Element Energy, along with scientists and engineers from Durham University and T2 Petroleum.  
Professor Eric Mackay, of Heriot-Watt University and principal investigator on the project, said: “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. Our findings suggest an eightfold increase in capacity is possible, plus a host of other benefits for a developing CCS industry in the UK.” 
Emrah Durusut, of Element Energy, said: “Our study has identified a variety of strategic benefits of brine production for both policymakers and storage operators. In addition to increasing storage capacity and achieving lower minimum unit costs at certain aquifers, brine production can also increase optionality for storage operators and allow operators to better utilise their existing storage assets within a defined licence area.”
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/or monitoring. A full report on findings will be released by the ETI later this year. 

Scottish Carbon Capture & Storage
UK Storage Appraisal Project

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Issue 62 - Mar - Apr 2018

CCS in the U.S.: Expanded tax credit could boost projects and start a CCS gold rush .. Moody’s: Coal will continue secular decline without CCS .. Capturing and using CO2 from ethanol STEMM-CCS: improving the safety of offshore CO2 storage .. Energy .....

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