5 march 2009

Storage of CO2 in empty gas field is unsafe

Environment: No experiments in residential areas

NRC Handelsblad, 5 March 2009

CO2 storage in a gas field under Brendrecht is an irresponsible experiment. The knowledge of CO2 in rock-formations is still insufficient, says Krijn de Jong

Nearly everyone is convinced that CO2 emissions should be reduced. One of the options is storing CO2 in empty gas fields under Barendrecht. Nonetheless, this is a bad idea. I limit myself to four reasons why we may be better off not storing CO2 and certainly not under Barendrecht.

CO2 storage uses a lot of energy. To store 10 molecules of CO2 you have to produce at least one and rather quickly three molecules extra because of the energy use in capture and storage. This means greater and more rapid use of fossil fuels. Moreover, much financial and human capital will be needed to create the enormous infrastructure for CO2 storage – money and time that can only be used once.

CO2-storage is forever. It’s often forgotten that the storage requires continual attention, now and in the future. Our great-grandchildren will also have to be concerned with monitoring a possible CO2 field under Barendrecht, when the current Shell project leader is long gone. Who will take on the administration of the field in a hundred years? The answer seems simple: the government. In practice, it is apparent how difficult it is, even for a government, to administer a complex infrastructure over a long period.

CO2 is not inert. CO2 storage is often seen as safe by comparing it with natural gas that has been stored underground during geological time. This is a false comparison. Natural gas, which consists mainly of methane, does not interact with underground rock formations, cement and pipelines. CO2 does. How safe is that? Nobody knows. In the report General Environmental Effects Study CO2 Storage [Algemene Milieu Effecten Studie CO2 Opslag] (July 1 2007) they say: “Even these stiff requirements are perhaps insufficient to insure that the cement and the steel pipelines will not be affected during thousands of years by chemical contamination by damp CO2”. When CO2 reacts with underground rock formation, its volume can increase up to 70%, with as a result an upward movement of the soil surface. Again from this report: “A consequence of injecting CO2 is a possible rise in the ground level. One expects that this rise will be smaller than the decline caused by the preceding natural gas pumping, but there is a considerable degree of uncertainty here”. This uncertainty is the result of a basic difference between the cause of the ground level subsidence (lower gas pressure in porous rock formation) and that of the ground level rise (chemical change in the rock formation).

CO2 storage is an experiment. At this time our knowledge of long-term underground storage is simply insufficient. From the same report: “There is not enough available data to accurately establish the risk level of underground CO2 storage”. The project in Barendrecht thus is an experiment and not, as it has consistently been called, a demonstration project. An experiment should be carried out in an appropriate environment. The Nevada desert in the United States seems to me in that respect more appropriate than Barendrecht in The Netherlands.

If then, there is no CO2 storage, what can be done? We have to produce less CO2, by using less fossil fuel, developing more efficient technology. And the most important thing is to put a great priority on the use of renewable energy.

The future is to the solar energy cell. But Shell has stopped its production of solar energy cells. And this company is now active in CO2 storage. Food for thought.

In any case, gambling is not an option in overcoming the CO2 crisis.

Krijn de Jong is Professor of Inorganic Chemistry and Catalysis at Utrecht University, The Netherlands

[Reprinted and translated with permission of the author.]

>>> Back to list