Carbon capture and storage (CSS) is expected to play a key role in decarbonizing energy sectors and economies to meet the terms of the COP21 Paris Agreement, which aims to limit global warming to 2oC and preferably 1.5oC. [Engerati-COP 21 Climate Agreement Sets Scene For Energy Sector]
To do this, atmospheric CO2 concentrations must be stabilized, both by reducing the volumes that are dispersed into the atmosphere as well as potentially in the future by removing CO2 from the atmosphere. CCS is a readily deployable technology solution to achieve this – but while the good news is that there is more than enough storage capacity, the technology must be progressed with increased funding as an urgent priority today.
"The ambitious targets set by COP21 in Paris are only feasible with the large scale deployment of CCS technology,” says Dr Niall Mac Dowell, from Institution of Chemical Engineers’ (IChemE) Energy Centre and Imperial College London, who has lead authored a new report on the future of CCS for the CCS Forum. “Our report identifies the key research and development needs for this area for the coming decade. I hope this will provide a meaningful contribution to CCS cost reduction and help remove the final barriers to the deployment of this vital technology”
The CCS Forum is a UK industry body comprising experts from academia, industry, and government supported by the IChemE Energy Centre, UK Foreign and Commonwealth Office, Royal Society of Chemistry and Imperial College London.
According to the report, to meet the Paris Agreement it is expected that 120-160Gt of CO2 needs to be stored from now until 2050.
The theoretical storage capacity is estimated at approximately 11,000Gt of CO2 with 1,000Gt provided by oil and gas reservoirs and 9,000-10,000Gt provided by deep saline aquifers. In addition, there is significant potential capacity in unminable coal seams. At the 120-160Gt by 2050 level, there is enough storage capacity for global CCS needs to be met well beyond the next century.
According to the Global CCS Institute there are 15 large-scale CCS projects in operation, with a further seven under construction. The total CO2 capture capacity of these 22 projects is around 40Mt/yr.
There are another six large-scale CCS projects at the most advanced (Define) stage of development planning, with a total CO2 capture capacity of around 6Mt/yr. A further 12 large-scale CCS projects are in earlier stages (Evaluate and Identify) of development planning and have a total CO2 capture capacity of around 25Mt/yr.
The two developers of CCS projects are the power sector and industry. The first large-scale power sector CCS project, the Boundary Dam project in Canada, with 1Mt/yr capture capacity, became operational in October 2014. The Kemper County Energy Facility in Mississippi with 3Mt/yr capture capacity, is currently in start-up testing phase. The Petra Nova project at the WA Parish power plant near Houston, Texas with 1.4Mt/yr capacity is due to begin operation by the end of the year.
Industrial CCS applications span natural gas processing, fertilizer production, coal gasification, hydrogen production and iron and steel making. More than a dozen large-scale, integrated CCS projects in the industrial sector are in operation. Since the first industrial large-scale project was pioneered on a natural gas processing plant in the US in 1972, industry projects have cumulatively captured, transported and permanently stored more than 100Mt of CO2.
CCS R&D requirements
The CCS Forum’s report identifies 10 priorities for CCS R&D, bearing in mind that translating major research findings to the market often takes many years.
These encompass the further development of capture technologies, but perhaps more important is the need to de-risk CO2 storage infrastructure around the world via exploration and characterisation of suitable geological structures. Whilst this effort is proceeding well in Europe, UK and USA, the Asia-Pacific region and China and India in particular, were identified as being in need of further detailed studies.
The commercial deployment of CCS rests not only on scientific and technical advances but also on the cost and performance impact of deployment. To date, research efforts aimed at improving CCS processes have almost exclusively focused on efficiency improvement and OPEX reduction. Going forward however, an increased focus on CAPEX reduction is recommended.
Decoupling the cost of CO2 capture from that of transport and storage also is important and a consistent, decoupled costing methodology that accurately reflects the costs of the major constituents of CCS is needed.
For the power sector, the role of electricity markets in the development of CCS technologies needs to be carefully evaluated. Greater understanding of the way in which CCS power plants will interact with the electricity markets is needed. As intermittent renewable energy generation sources more significantly penetrate the energy system, thermal power generation will be increasingly displaced from the electricity market. It is therefore highly unlikely that CCS plants will provide baseload generation. Thus the ability of CCS plants to provide ancillary services to the electricity grid will need to be explicitly valued, along with the role of CCS in providing co-benefits such as low carbon heat and negative emissions.
Finally, it is vital that meeting near-term targets does not come at the expense of long-term targets. For example, meeting the Paris Agreement depends on using bioenergy with CCS (BECCS) but this cannot be implemented without a mature and established CCS industry. Climate change itself is expected to cause enormous direct costs due to changing weather patterns and crop yields. However these should vastly exceed the costs of implementing CCS.