As part of researching a forthcoming Gas Turbine World article about retrofitting CCS for gas-fired power plants, last night I attended a ‘Green in the City’ panel discussion put on by EcoConnect to discuss the future of carbon capture technology. Attendees would be forgiven for thinking carbon capture has no future.
There is no shortage of financing available for CCS. Norway has called CCS its “moon landing” and has state oil company Statoil on the case. The EU’s NER300 programme to fund at least eight CCS demonstration projects is worth around €3-4 billion. In the UK, the Government’s £1 billion pot funded out of direct taxation to pay for up to four CCS projects remains unspent after it pulled the plug on Scottish Power’s Longannet scheme.
CCS is seen as essential for the decarbonisation of the power sector. As Klaus Lackner, Professor of Geophysics at Columbia University, said: “Either you have CCS, or you deny climate change. Or you abandon fossil fuels.” Difficult to argue with. But is the solution to decarbonizing the power sector piping CO2 hundreds of miles out to sea, sticking it under the seabed and putting a big plug on top? And should it need a carbon price of $200 per tonne to be economically viable, as Lackner suggests?
According to Dr. Alan Knight OBE, a former chair of the UK Government’s Roundtable on Sustainable Consumption, no. Knight sees CCS as little more than convoluted landfill. “The big companies like Google are not turned on by carbon landfill,” he said. “Isn’t it better to create commercial products with CO2? Those carbon molecules are an exciting resource for fuel security and food security.”
I digress. Besides the cost of building carbon capture units, the operational costs, the thermal efficiency penalties and other engineering drawbacks, the other crucial element of CCS – storage – appears to have been overlooked. This is a shame says Dr. Ward Goldthorpe, who heads up the Crown Estate’s CCS programme, because the amount of CO2 to be stored to hit IEA 2050 carbon targets requires infrastructure three times the current size of the entire European gas industry.
The problems of storing CO2
There’s a general impression that captured carbon dioxide can be easily transported across the existing natural gas pipeline infrastructure, swapping CH4 for CO2. That could be highly dangerous, according to the UK Health and Safety Executive, due to highly corrosive ‘dense phase’, pressurized CO2.
The problem is that CO2 captured from power plants always contains moisture. Wet CO2 is very acidic and the potential for corrosion, leakage and even explosions is such that either the CO2 will have to be dried, which imposes a further efficiency penalty, or the pipelines have to made from corrosion-resistant steel. Both techniques could be prohibitively expensive.
The FEED study of the UK’s failed Longannet project is quite an eye-opener. Anyone who thinks Norwegian Prime Minister Jens Stoltenberg was exaggerating when he likened CCS to landing on the moon should have a look at the Longannet ‘Post-FEED Top 50 Risks’ document. Notice how many of the Top 10 concern CO2 storage.
While Europe is relatively advanced in CO2 storage, namely the Norwegian enhanced oil recovery (EOR) projects, a huge amount of technical work needs to be done for regulating CO2 with impurities, i.e. water, says Goldthorpe. “The regulatory framework is essentially adapted from the US petroleum industry, but a lot of CO2 transport in the US is pure CO2. Devising standards for the CCS industry that can cope with CO2 plus impurities is still a work in progress.”
Goldthorpe says the major stumbling block for CO2 storage from power plants is the total lack of a value proposition. “Unlike the EOR projects in the US, we are trying to implement in one fell swoop integrated CCS projects with no associated value proposition at all. The public funding is not prepared to underwrite the awkward risk-sharing and liability issues which pop out of the integrated model.”
DECC says “developing storage sites may be an uncertain, potentially time-consuming, costly and risky business opportunity”. That’s putting it mildly. But if CCS is to take off, these issues need urgent addressing. Is it worth the expense?