Wednesday, 16 December 2009

Questioning Carbon Capture and Storage

With all eyes turned to the Copenhagen summit, means of reducing Carbon Dioxide emissions and/or storing it will be exercising the minds of policy makers the world over. One technocratic solution that is receiving serious attention among scientists, politicians and environmentalists is carbon capture and storage (CCS). This technology entails either drawing C02 out of the atmosphere or capturing it at point of release, and then storing it so it cannot contribute toward global warming. However, CCS is not an just an engineering challenge that will allegedly solve the problem of climate change mitigation - there are a whole host of political questions bound up with it too. It was some of these issues James Meadowcroft addressed at Keele last Tuesday in his paper 'CCS: Promoting the Transition to Sustainable Energy or Enhanced Carbon Lock-In?' This was to promote his recent co-edited book, Caching the Carbon, which looks at CCS politics and policy in the USA, Australia, Canada, Britain, Germany, the Netherlands, Norway and the wider EU.

The talk began with the state of the technology, which can be divided into three elements. The capture itself, transporting the carbon, and storing it each represent different engineering challenges and the technology itself is uneven - this is to say nothing of integrating them together.

Of the elements of CCS, capture is the most challenging. At present three to four per cent of what comes out of a smoke stack is carbon dioxide, so how to separate it from other emissions? One possible solution is gasifying coal, which would allow for the CO2 to be extracted and burn the remaining hydrogen for fuel. The problem with this is even though being worked on in the commercial sector, the technology has yet to mature to the level of wide scale application. Another big problem with capture is the cost. At present performing carbon capture on a coal-fired power station would require a dedicated chemical plant to be built alongside it, and anywhere in the region of 15-40% of the station's output required to power it. Not surprisingly a lot of research is focusing on getting the capture cost down.

Transportation represents less of a challenge as we already have extensive experience of transporting gas over distances, be it in container ships, by road or rail or through pipelines.

More problematic is the storage. The three main options is storing it underground, pumping it into the ocean or making it react in a particular way to produce "artificial" limestone. The problem with the ocean is that it is not a store as such but rather one means by which CO2 is cycled back into the atmosphere (long-term). Pumping it into deep sea trenches is a possibility, where the pressures would liquify the gas and keep it in place - but this is to say nothing of the damage it could do to deep sea ecology, nor is there a guarantee that it would find its way back into the atmosphere. Geological storage therefore seems more practical, but this is far from problem-free. Already the US oil industry pumps CO2 into oil wells as a means of enhancing production. But thanks to fissures in the ground, one could not fill a well and then cap it - methods would have to be developed to ensure any gas pumped into them stays there. Another possibility is pumping it into deep coal seams or saline aquifers beneath the water table. But these locations have to be stable for a long period of time as it take 50,000 years for the gas to be incorporated into rock (leaving aside the disastrous consequences of a vast store of captured carbon suddenly "bursting").

There are four strategic ways of thinking about CCS, assuming the engineering problems can be resolved. The first would be attached to 'large point source emitters', such as refineries, power stations, big factories and so on. These are responsible for about half of the world's carbon emissions. The second is small and mobile sources, applicable to homes and cars. The third is biomass, which can be carbon neutral provided closed carbon-energy loops can be created. For instance, burning plant matter, growing it, burning it, etc. Lastly is the possibility of artificial trees that could extract carbon directly from the atmosphere and store it on site (eliminating the need for transport).

CCS itself is being driven by the economics of the seven countries the study addresses. Australia is particularly keen because 10% of its GNP is invested in coal, which is also its biggest export and primary source of energy. It has been particularly keen on storing carbon as rock. Norway on the other hand is 100% hydro powered, but would like to build stations so it can burn gas and export energy. Like Australia, for the UK CCS is about utilising its substantial coal reserves while still staying on course to meet its emissions target. Also, for the US, Australia and Canada CCS was offered as an alternative by them to the binding reductions made at Kyoto.

A number of narratives have emerged around CCS. The first is enthusiastic and tends to find most favour among policy makers - that seeing as renewable sources are not ready, and recognising fossil fuels will remain the foundation of energy production at least in the medium term, CCS offers a way of mitigating the effects and easing the transition later on down the line. Plus CCS opens up new business opportunities.

Secondly there is a more equivocal position. It recognises CCS has problems and therefore we shouldn't wait until they have all been sorted out. Right now governments should be prioritising conservation, promoting and investing in renewables. The danger with CCS is it might soak up resources that may be more gainfully employed elsewhere.

Lastly there is the more critical position. This holds CCS as an 'end of pipe' solution that will effectively delay the transition to a post-fossil fuels economy. It is not viable now and may be already 'too late' (whatever that means). Furthermore, even if CCS gives us a form of clean coal, other challenges regarding its polluting effects remain.

For Meadowcroft all of these arguments have some merits, but problems too. For instance the argument it is too late for CCS is a non-starter - seeing as no one knows if there even is a 'tipping point' for the Earth's climate, we should operate with the principle that anything that brings emissions down is useful. But turning to the enthusiast's love-in with carbon trading schemes, he expressed some scepticism over the speed at which markets can generalise an incentive to bring emissions down. Administrative measures and regulatory initiatives by states are much faster.

Assessing the viability of CCS itself, it has acquired a political gravity of its own and, for obvious reasons, the global oil lobby are fully supportive of it. But as it is CCS requires significant state support. He estimated 20-30 plants are needed to test it at scale, but at well over $1bn apiece oil companies are unlikely to stump up all the funds. Furthermore, assuming the technology works who administers and is held responsible for storage over the long term? Not many companies will be keen on indefinite liability.

So what we are left with, in all essentials, is a great deal of hope being invested in an unproven technology that not only has to overcome significant engineering hurdles, but also requires the kind of state financing that would have been hard to secure even during the boom times. However for Meadowcroft, whatever the difficulties the fact so many are addressing CCS will open up other as yet unexplored opportunities for tackling climate change.

2 comments:

Anonymous said...

The problem with CCS is that it is a solution of choice for industry primarily because it implies no interuption of the profit stream rather than being a sustainable solution in the longer term.

Whilst the world still has significant supplies of coal it is clear that oil will run out in the next 20-50 years depending on whose estimates you believe. In turn this means it will be unaffordable to ordinary people well before that. We are effectively on the verge of a post fossil fuel economy which needs solutions now rather than in the indefinite future.

If business want to pursue CCS that is fine but let them finance it. Government's should concentrate the limited resources they have on the longer term issues of developing viable non fossil fuel sources of energy which should be publicly owned. All of experience tells us that, left to the market, solutions will only be found if they are profitable - thus the emphasis on CCS. The current position demands a better, longer term and more secure position than that.

Phil BC said...

One thing I didn't point out re CCS which is relevant to your point is that new coal and gas fired power stations are coming on stream with the promise that they can be retrofitted with CCS when the technology finally comes along. In other words, CCS is being used as an excuse to pollute away in the here and now!