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 energy requirement and cost. Therefore, this study focuses on the chemical and physical activation of the dissolution and carbonation of Mg-bearing minerals and the tailored synthesis of high-purity precipitated magnesium carbonate (PMC) and iron-based nanoparticles (e.g., chemical looping sorbents and WGS and F-T catalysts). The physical properties of PMC are controlled to mimic commercially available CaCO3-based filler materials, while iron-based chemical looping sorbents are synthesized for maximum oxygen carrying capacity. The thermodynamic and mechanistic studies are being conducted to investigate the effects of pH, reaction time, and reaction temperature on the mean particle size, particle size distribution, and particle morphological structures.
Overall scheme of carbon mineral sequestration
Proposed mechanism of serpentine dissolution
pH swing Carbon Mineral Sequestration Technology
Life cycle analysis
In order to completely evaluate the developed CO2 mineral sequestration, a life cycle analysis should be performed using an appropriate system boundary. Capturing CO2 from the flue gas of the coal-fired power plant and sequestering it can reduce the global warming potential of electricity production; however, the overall penalty is an increase in fossil energy consumption, which would result in further CO2 emissions. The additional energy will be used to maintain a designated plant capacity, to capture and pressurize CO2, and to transport and execute the sequestration process. Therefore, the net energy analysis and the emission inventory analysis that cover the entire carbon mitigation “life cycle” of capture, separation, transportation, and sequestration are being investigated.
This project is partially supported by ORICA Ltd. and NYSERDA.