(715c) Tailored Synthesis of Precipitated Magnesium Carbonates as Carbon-Neutral Filler Materials During Carbon Mineral Sequestration

Predictions of global energy usage and demand trends suggest that fossil fuels will remain as the main energy sources for the foreseeable future. Unfortunately, the amount of anthropogenic carbon emitted during the energy production is expected to increase, so that the atmospheric CO2 concentration could reach 580 ppm, a threshold value thought to trigger severe climate change, within a mere 50 years, unless action is taken. Thus, reducing carbon dioxide emissions in order to stabilize atmospheric CO2 levels is crucial. The carbon capture and storage (CCS) schemes generally consist of three major steps: CO2 capture, transportation, and sequestration. Currently, the geological storage of carbon dioxide is considered to be the most economical method of carbon sequestration, while mineral carbonation is a relatively new and less explored method of sequestering CO2. The advantage of carbon mineral sequestration is that it is the most permanent and safe method of carbon storage, since the gaseous carbon dioxide is fixed into a solid matrix of Mg-bearing minerals (e.g., serpentine) forming a thermodynamically stable solid product. The current drawback of carbon mineral sequestration is its relatively high cost. Therefore, this study focuses on the tailored synthesis of high-purity precipitated magnesium carbonate (PMC). The physical properties of PMC are controlled to mimic commercially available CaCO3-based filler materials. The effects of pH, reaction time, and reaction temperature on the mean particle size, particle size distribution, and particle morphological structures have been investigated. Finally, the PMC are synthesized in a solution containing carbonic anhydrase.