GCCSIとIEAGHGにより、CO2に含まれる不純物が貯留に及ぼす影響に関するレポート”Effects of impurities on geological storage of CO2″が公表されました。


-Impurities that are incondensable (N2, Ar, O2, H2O) and cannot be converted to liquids at the normal pressure and temperature conditions in the reservoir can impact on storage capacity, injectivity and buoyancy.

-The non-condensable components can increase the bubble-point pressure and decrease the critical temperature of the fluid overall. A high impurity oxyfuel stream shows the greatest effect.
 These effects are most pronounced in relatively shallow (ca 900m) low temperature reservoirs (33°C), where capacity could be reduced by as much as 40 per cent.

-The most significant chemical effects are seen from SOx, NOx and H2S where sulphuric acid and precipitates may occur with the right reagents.

-Post-injection analysis should include the impact of acidic impurities in the desiccated well zone.