Not only that, burning the coal or the oil to generate the heat to release the CO2 from limestone also releases CO2. The whole thing is nonsense.
Actually the science behind this is quite sound. This is a form of chemical looping combustion if anyone bothered to look at the research behind the article and not just knee jerk arm chair scientist at it. The conversion of lime to Calcium Oxide is is endothermic having a reaction temp of ~900’C the CO2 adsorption reaction is exothermic having a reaction temp of ~650 they obviously are using fluidized bed reactors with integrated combustion which are designed to move hot micronized solid suspensions at high temperatures from one reaction zone to the other thus the lime is both the reactant and the heat transport medium leading to high thermal transfer efficiency are all fluidized beds exhibit. By using the exothermic reaction heat to preheat the incoming reactants to the higher temperature endothermic 900+’c zone heat recovery is achieved the energy extraction point for the generation of steam and therefore power is between the 900 and the 650’c stages. There is no separate combustor to heat the lime to degas it the lime combustor is the power combustor and the lime is the primary heat transfer medium. Again this a chemical looping combustion process using lime as the primary heat transfer and chemcial reagent medium and high pressure 700+’c steam as the secondary power generating cycle. The breakthrough is using the heat of the exothermic cycle carried in the recycled hot lime to lower the energy needed to separate the CO2 from the combustion products stream. Essentially you only need to supply the chemical energy to break the bonds of CO2 from the CaO minus the recovered energy from the exothermic reaction which is significantly less than using animines. This additional chemical energy is already present in the combustion process primary heat rate as a slightly higher coal burning rate, but coal is cheap and CO2 is getting expensive so the economics probably will work out some time soon. This process will also yield high purity CO2 ready to be piped to an oil field for EOR recovery operations where secondary producers pay dearly for CO2 in high purity high pressure form. For those curious yes as a matter of fact I am a scientist ;)