Carbon Capture and Storage (CCS) comes from the very logical idea that the biggest part of GHG emissions actually comes from the combustion of fossil fuels.

Looking at it in the perspective of our planet history, fossil fuels themselves find their origin in antediluvian vegetation, transmuted through ages into coal, oil and gas.

Vegetation in itself being a natural CO₂ absorber, the idea is to replace the underground extracted 'finished product' by the residual GHG emissions, f.i. in a liquefied state, so the cycle is complete.

Although this could sound simple, the investments required are quite substantial and we are just at the beginning of several test phases for the three main steps involved in CCS:

Capture - Transport - Storage

Basically, capturing the residual GHG from fuel combustion could occur following three different paths:

- Oxy-fuel combustion (replace air by oxygen) in order to eliminate nitrogen from the residual fumes; this facilitates greatly the filtering of CO₂.

- Post-combustion: filtering CO₂ from residual fumes by using different solvents (chilled amonia, f.i.)

- Pre-combustion: separate CO₂ from nitrogen prior to combustion and use the residual nitrogen as the actual fuel.

Storage can occur in various types of geological formations. Primary options are depleted oil and gas fields as well as natural underground cavities containing salty water (deep saline aquifers).

The main expected/known issues with storage are related to the potential leaking of CO₂ into the neighbouring geological formations (fresh water contamination) and also the fact that it will be terribly difficult to look for responsibilities in case of problem due to the potential litigation related to the underground repository's ownership. Then there are voice claiming that CO2 should be deemed a waste product, and as such cannot be disposed underground.

For further information, do not hesitate to enquire.