Blue Planet's technology uses CO2 as a raw material for making carbonate rocks. The carbonate rocks produced are used in place of natural limestone rock mined from quarries, which is the principal component of concrete. CO2 from flue gas is converted to carbonate (or CO3=) by contacting CO2 containing gas with a water-based capture solutions. This differentiates Blue Planet from most CO2 capture methods because the captured CO2 does not require a purification step, which is an energy and capital intensive process. As a result Blue Planet's capture method is extremely efficient, and results in a lower cost than traditional methods of CO2 capture.