Carbon capture and storage key to unlocking unburnable carbon, says white paper

Imperial has its own carbon capture pilot facility

A new review suggests that if carbon capture and storage technology can be refined, it will enable the world to use more of its unburnable carbon.

Carbon capture and storage (CCS) technology involves catching harmful carbon dioxide emissions from factories and power stations. These emissions are transported via a network of pipes and trapped inside the microscopic pores of rocks located kilometres underground. See infographic for more details.

Currently, CCS technology is capable of capturing approximately 85 to 90 per cent of total carbon dioxide emissions, with the remaining 10 to 15 percent of residual emissions emitted into the atmosphere. In a new review, researchers from the Sustainable Gas Institute at Imperial College London argue that if these residual emissions could be reduced to around one to five per cent, this would enable the world to unlock much more of its fossil fuel reserves, whilst staying within target limits for global temperatures.

The concept of ‘unburnable’ carbon first emerged in 2011. It stemmed from observations that if all known fossil fuel reserves are extracted and used, then carbon dioxide emissions would exceed the world’s carbon budget and have a significant negative effect on the global environment. Governments agreed at the Conference of the Parties in Paris (COP21) meeting to limit global warming to less than 2°C. To achieve this a large proportion of fossil fuels would need to remain untouched or unburnable.

Now, researchers from Imperial have developed models that predict the impact of CCS on the use of fossil fuel resources, assuming the technology continues to improve its capture rates.  They calculate that that the CCS technology could enable more of these unburnable fossil fuel resources to be unlocked over this century, while still limiting global warming to 2°C.

The overall message from the report is that CCS is an important technology, which needs to be implemented globally alongside alternative low carbon sources such as renewable energy if climate targets are to be met in this century.

Professor Nigel Brandon, Director of the Sustainable Gas Institute at Imperial College London, said: “Climate change is one of the world’s most pressing issues. Finding solutions that limit global warming, while enabling the world to make a smooth transition to a much lower carbon future, is paramount.

“This report shows us a way forward, which may enable us to continue to use fossil fuels as an important part of the energy mix, while remaining in the 2°C limitations. That said, we won’t get there unless there is greater support from governments for adopting CCS, together with more investment in improving CCS technology to reduce its residual carbon dioxide emissions.

“We hope that our review will encourage industry and governments to realise CCS’s potential in helping the fight against climate change, as part of a portfolio of investment in low carbon technologies.”

Previous studies exploring the impact of CCS on unburnable carbon have only considered a timeframe of up to 2050, during which time CCS would be expected to have a relatively small impact on the amount of fossil fuels that can be used.

In the new white paper, the team extended the timeframe to 2100. The modelling showed that up to a third more fossil fuel resources could be consumed globally, than if CCS was not in use, while still remaining in 2°C limitations.

Calculations up to 2050 show that around 3,500 to 5,000 exaJoules could be consumed if CCS was implemented globally, but by 2100 this increases to 14,000 to 16,000 exaJoules. The team say that is enough energy to power the US for 140 to 160 years.

The total global underground storage capacity for carbon dioxide was also calculated in the report. The team estimated that there would be around 10,450 to 33,153 Giga-tonnes of capacity available. At current global yearly emission rates, this would equate to around three centuries of storage capacity for the world.

The team also reported on the barriers that need to be overcome if CCS is to be successfully implemented. Some of these barriers include the initial costs of implementing the technology, the lack of market and regulatory arrangements currently in place, as well as major gaps in the overall CCS supply chain, including a shortage of skilled labour, and a cautious public perception of the technology.

To address these issues in the short term, the researchers say more research needs to be carried out to refine CCS technology.

Alongside this, a range of new policies need to be implemented that support development of this technology. They believe this needs to happen at the early stage when more demonstration plants are being built and maintained right through to the application of CCS in a global mass market.