The scalable production of calcium and magnesium carbonate starting with CO2 is limited by several factors such as the slow kinetics of CO2 hydration and dissolution of Ca- and Mg-bearing reactants. To accelerate the kinetics of CO2 conversion to calcium and magnesium carbonates, we investigate two modes that involve in-situ changes in the aqueous chemistry to facilitate the capture of CO2 using MEA, and the release of CO2 into the aqueous phase to produce higher conversions of calcium carbonate. In the first mode, continuous CO2 flow at 1 atm is provided such that MEA in the aqueous phase captures CO2 and supplies the captured carbon-bearing species for reaction with dissolved calcium. In the second mode, MEA pre-loaded with CO2 was introduced into the system without a continuous supply of CO2. Complete conversion of calcium oxide to calcium carbonate was achieved using both modes. Further, the extent of carbon mineralization achieved with calcium silicate was 36% in Mode 1 as opposed to 20% in Mode 2 at 50 oC for a reaction time of 3 hours. These data suggested that amine-bearing solvents undergo continuous looping between the CO2 loaded and release states which facilitate the accelerated conversion of calcium-bearing oxides and silicates to calcium carbonate. The proposed research approach is a less studied but highly promising route for accelerated carbon mineralization.

Integrated CO2 capture, conversion, and storage to produce calcium and magnesium carbonates via amine looping strategies

2019 Spring National Meeting

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