Glossary : 

Adsorption: a surface phenomenon whereby gas or fluid molecules bind to the solid surfaces of certain substances according to variably active processes. Clays and zeolites are particularly effective natural adsorbent media; active carbon is an excellent adsorbent.

The result of human intervention.

Aquifer: a permeable geological formation that contains water. The most superficial aquifers contain fresh water used as drinking water. Aquifers at greater depth contain brine that is totally unsuitable for human consumption. These are called deep saline aquifers. Aquifers sometimes contain oil and gas fields where the water in the rock pores has been replaced locally by hydrocarbons. They may also contain fields of pure CO2 of natural origin. This is the basis for the idea of storing CO2 in rock pores, thus mimicking natural CO2 fields.

CO2(carbon dioxide): one and a half times as heavy as air, CO2 does not exist in liquid form under atmospheric pressure conditions; one ton of CO2 contains 0.27 tons of carbon.

CO2 sink: systems found essentially in seas, forests, and the ground that naturally absorb part of the CO2 released into the atmosphere.

EOR, or Enhanced Oil Recovery: a process for stimulating the production and increasing the recovery from oil reservoirs.

GHG, or greenhouse gases: the two main gases responsible for the greenhouse effect are water vapour (H2O) and carbon dioxide (CO2).
The other main 'natural' greenhouse gases are methane, CH4, nitrogen protoxide, N2O and ozone, O3.
The main industrial greenhouse gases are halocarbons such as HFC, PFC and CFC, and sulphur hexafluoride, SF6, which absorb infrared rays very strongly, much more so than CO2, and may remain in the atmosphere for very long periods of time, up to 50,000 years.

Gt (gigaton): 1 Gt = 1 billion tons.

IPCC: the Intergovernmental Panel on Climate Change. This group was formed in 1988 by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP). Its role is to evaluate pertinent scientific, technical and socio-economic information with a view to understanding the risk of anthropogenic climate change.

Monitoring: the quantitative and qualitative surveillance of natural environments or industrial operations using instrumental networks in conjunction with predictive models.

Partial oxidation: a process used in industrial installations to produce synthesis gas from various fuels (coal, biomass, heavy-grade oil, etc.) and oxygen.

Conduit for transporting gas or liquid over long distances.

Ppmv: parts per million by volume; a way of describing the content of a given substance (carbon dioxide, for instance) found in a gaseous sample; one of these units corresponds to 1 cm3 per m3.

Steam reforming: a process used to produce synthesis gas from light fuel - natural gas - and water vapour. Steam reforming of natural gas makes it possible to obtain the highest concentrations of hydrogen.

Synthesis gas, or syngas: an intermediate product, a mixture of carbon monoxide, CO, and hydrogen, H2, resulting from a partial oxidation or from steam reforming. Synthesis gas is used in many industrial applications to generate energy (electricity or hydrogen) and chemical substances (synthetic fuels).

At specific pressures and temperatures (over 74 bars and 31°C), carbon dioxide is in a fluid state but behaves as a gas.