Climate concerns: Carbon capture and storage

Olav Kårstad, StatoilHydro, Norway

Mitigating CO2 emissions at the necessary pace will require quite drastic changes in the energy system. A large scale transition from fossil fuels to other energy sources looks impossible in the short and medium time frame. In this picture there will be a need for transitional technologies to handle short to mid term energy demand. The International Energy Agency (IEA) energy outlook scenarios indicate that for the next decades, CO2 capture and geo-storage (CCS) will play an important role in combating climate change together with end-use efficiency and other options. The technologies of the CCS-chain have been proven to a certain extent, but should still be considered to be in their infancy.

Norway was one of the very first countries in the world to recognise and act against global warming. The UN Report of 1987, "Our Common Future" (the so-called "Brundtland Report") was an early warning on the climate change challenge. Mrs. Brundtland later became Norwegian Prime Minister, and in 1991 the administration introduced the world's first CO2 tax, currently at above $60/ton, for the offshore industry and some other sectors.

The Sleipner CO2-injection became the world's first large scale CCS project for climate change reasons when it started operating in 1996. By now, a decade later about 10 million tonnes CO2 has been stored in the so-called Utsira sandstone formation.

Over the years a few other CO2 geo-storage projects have emerged: The In Salah injection in Algeria, the Weyburn project in Canada and the Snøhvit CO2-project in the Norwegian part of the Barents Sea. All of them in the order of 1 mill tonnes of CO2 per year. In addition a few smaller scale pilot injection schemes have been operated by research organisations on several continents.
The US and to a lesser extent a few other countries have a long and successful history of increasing oil recovery from old fields by injection of CO2. Today over 80 such EOR-projects are in operation in the US alone.

The main challenges for wide deployment of CCS are the economics, the immature technology as well as public acceptance. The cost of mitigating one tonne of CO2 varies with type of source, distance to a CO2 storage opportunity, onshore or offshore storage, the market value of CO2, policy, offset possibilities and so forth. As a rule of thumb, CO2 capture costs amounts to about 70% of the total while transportation and storage to the remaining 30%.
A key element to a successful CCS policy is to acknowledge that one tonne of stored CO2 is equivalent to one tonne of CO2 not emitted. Viewed globally, this is far from the regulatory reality today.

Accepting CCS is accepting a low risk that a small fraction of geologically stored CO2 might seep to the atmosphere in the long time frame. The other side of the coin is that today the world is accepting the risk associated with 100% of the anthropogenic CO2 emissions entering the atmosphere through smoke stacks.

World-wide there are some 5000 power plants, 600 refineries and other large facilities adding up to about 8000 large (>0,1 mill tonnes/yr) point sources of CO2. These plants emit nearly 60% of the world's fossil fuel derived CO2 that today ends up in the atmosphere. This is the context in which geo-storage of CO2 will play a crucial role to tackle climate change in the 21st century.