CO2 sequestration, as a means to fight against greenhouse gases, is currently the object of at least eight research programmes in the world, the evolution of which was the focus of works at the 'X European Tecnology Talks', held in November last year at the Cité des Sciences et de l'industrie, in La Villette, Paris.

After the measures for the reduction of energy consumption and substitution of the more pollutant fuels, the capturing of the carbon dioxide yielded from the great industrial plants and its sequestration into the deep strata of the underground seems a very promising means to reduce pollution.

From a technological point of view, this solution remains to be improved, to make such projects more feasible. First experiments are underway at an industrial level such, as for example , those conducted by TotalFinaElf, in the context of its "Gas residuo" project.

Currently, the most imposing recovery and stocking operation for CO2 is the one taking place in the gas platforms in Sleipner, in the Norwegian area of the Northern Sea. A million tons of CO2/per year are extracted from the natural gas produced, to bring back its tenor to commercial standards. The recovered carbon dioxide is injected, since 1996, in seawater over 800 metres deep, under the Northern Sea. These operations are combined with a European research programme, called SACS - Saline Aquifer CO2 Sequestration -,in which particular IFP (Institut Français du Pétrole) and TotalFinaElf take part.

The objective is that of acquiring knowledge on CO2 behaviour in the underground layers and build a mathematic model of the tank's architecture, in order to be able to use tool that will enable projections and evaluate its behaviour in the next thousands of years. The acquired knowledge will give rise, in the course of 2002, to the publishing by IFP of a "Good practice guide" for underground confinement of CO2. For its part, BRGM (Bureau des Recherches Géologiques et Minières) works on the "natural analogous". There are in fact many CO2 reservoirs existing in the subsoil, some of which have already been exploited for decades.

After the stocking safety problem, the main obstacle for CO2 confinement is nevertheless still of  financial nature, as emphasised by Howard Herzog - chief engineer of MIT's Energy-Environment lab - who estimates that the confinement operations will cost, at the current state of the art, between 250 and 300 dollars per ton of carbon (between 70 and 80 dollars per CO2  ton), of which almost 80% for the separation and capture if the carbon gases.
For this technology to represent a valid solution to pollution it is precisely in this field the most important progresses must be made.

March.2002