Carbon capture and storage technology moving forward
The ‘unproven’ technology may finally prove its worth as projects around the world are getting the green light
The last few months have brought some long-overdue progress for carbon capture and storage (CCS) technology – which buries harmful emissions underground. It may finally be moving closer to realising its promise as the fourth pillar of climate change mitigation – along with renewables, nuclear power and efficiency.
In November, the Abu Dhabi National Oil Company (ADNOC) and its clean energy vehicle Masdar signed an agreement to push forward with carbon capture from a steel plant, the world’s first large-scale industrial capture project. And in February, a carbon capture scheme on the gas-fired plant at Peterhead, Scotland, was awarded design funding, as one of two projects in the UK’s CCS competition. Two coal-fired capture plants are moving closer to operation – Boundary Dam, in the Canadian province of Saskatchewan, is due to start in April; and one in Kemper County, Mississippi, US, is due to be finished by the end of this year.
Carbon capture has lagged behind renewables in recent years. The dramatic fall in the cost of solar power and, to a lesser extent, wind, has contrasted with escalating costs for coal-fired power plants. Surging US shale-gas production undermined the economics of even conventional coal-fired power.
CCS has attracted stiff opposition from some environmental groups, but has suffered mostly from the large size – and hence cost – of any individual project, as well as the lack, in the absence of a realistic price on carbon, from a commercial rationale. The Abu Dhabi, Boundary Dam and Kemper County projects all depend on commerciality to sell their captured carbon dioxide (CO2) for enhanced oil recovery.
Nevertheless, these large-scale projects are important for four reasons. Firstly, carbon capture projects so far – such as the pioneering project at Norway’s Sleipner field in 1996 – relied on storing CO2 that was being captured anyway, from gas processing. The new wave of developments will show how CCS works on coal power, gas power and industry, and establish a realistic cost base. It will no longer be possible for opponents to write off CCS as an “unproven” technology.
Secondly, these projects will test whether, and how, community consent can be won. The Peterhead project, involving Shell and Scottish & Southern Energy, will inject CO2 offshore, where this is less problematic.
Thirdly, they will establish commercial models where power utilities and oil companies – two very different businesses – can learn to work together. And fourthly, they will bring down the costs of future CCS projects, by gaining real-world construction and operational experience.
CCS power may appear expensive, but should be competitive with new nuclear-generated electricity, and – unlike most renewables – is steady and reliable. Some interesting technologies also promise much lower costs, such as burning fuel in pure oxygen, as in Maersk Oil’s TriGen process, or separating out CO2 using membranes or exotic new materials. Turning CO2 into solid minerals would allay fears about leakage from underground storage, and possibly create new revenue streams.
Regulatory action is finally creating some commercial incentive to use carbon capture. The US Environmental Protection Agency’s new proposed rule on emissions standards would essentially rule out new coal-fired power plants without carbon capture. Although the US’s CO2 emissions have fallen impressively – to the lowest level since 1994 – as cheap gas from shale has displaced coal, this will not continue indefinitely without further action.Tantalisingly, with the world likely to far overshoot CO2 limits, carbon capture could even lead to net removal of CO2 from the air, either from biomass-fired power plants or “artificial trees”. A number of key industrial processes – cement, which produces 5% of global carbon dioxide emissions, steel-making as at the Abu Dhabi plant, chemicals, oil-refining and fertilisers – yield CO2 as an intrinsic part of the process, with CCS the only realistic way to eliminate it.
The EU has the opposite problem. Rising concerns over energy bills, coupled with the eye-watering cost of offshore wind power and the UK’s new nuclear plant at Hinckley Point, show the value of another clean energy option. Expensive gas and Germany’s nuclear phase-out have forced a shift to an expensive – and not very climate-palatable – brew of renewables and coal power. The International Energy Agency estimates that CCS could cut the cost of meeting global climate goals by 70%.
A new realisation has dawned that worldwide gas resources are immensely abundant – 7,300 trillion cubic feet (cf) of shale gas in the US Energy Information Agency’s estimate, with 6,600 trillion cf of conventional gas, or more than a century’s consumption at today’s rates. With these figures, gas might not just be a short-term bridge to a renewable future – but combined with CCS it could be a destination fuel.
Meanwhile, coal power may be struggling in the US and its European revival will presumably be cut short eventually. But coal remains immensely important in Asia, in coal-rich, gas-short countries – mostly obviously India and China, but also populous Pakistan, Indonesia and Vietnam. Even if China develops its huge estimated shale gas resources, coal will remain a vital part of the energy mix for decades.
Progress on carbon capture has been frustratingly slow. But it may now be picking up speed. The next three to four years will be crucial in establishing its commercial viability. The results will have major implications for our future climate-friendly energy mix – just renewables and nuclear, or a balanced mix with clean fossil fuels?