Experimental Study On The Reaction Mechanism Of Carbon Dioxide Mineral Carbonation

Coal is a main kind of energy source in China, but coal combustion will bring great pollution to the enviorment and do harm to the health of human beings and life of wild plants and animals in China. Emission and control of carbon dioxide (CO2) from coal combustion is now an emerging and frontier area and going to attract more attention in future.Although the carbon dioxide separation technics have been full maturity, a mass of carbon dioxide are emitted into atmosphere. Carbon sequestration as mineral carbonates is a novel method with potential to be implemented with acceptable economics to dispose carbon dioxide in large-scale.Some innovative research of carbon sequestration as mineral carbonates under middle and low-pressure has been made in this paper.In the first place, this article summarizes the hazards of carbon dioxide to the environment and society, the sources of carbon dioxide in atmosphere and the current control technologies in the world.Explain the mineral carbonation reaction mechanism in theory aspect. Compared two different mineral carbonation reaction models and analyzed the energy equilibrium. After that, the thermodynamic analysis has been carried out using the Matlab programs. The results show that the mineral carbonation reaction can be implemented under higher pressure when the reaction temperature is lower than 500K.The solution experiment researches have been carried on the oscillating thermostaticwater-bath. The effect of different factors which influence the solution of ore in distilled water such as temperature, particle size, thermal treatment and agitation have been analyzed. It has been observed that the highest solution rate of ore in distilled water appears during the first twenty minutes. Then, antigorite ore has been chosen to be the ore sample for mineral carbonation experiment due to the higher dissolvability.An experiment platform of carbon dioxide mineral carbonation has been designed and built according to parameter of the test. Abundant experimental studies are performed in the paper to investigate the factors that influence the rate of carbonation reaction, such as reaction temperature, reaction pressure, particle size and pretreatment.X-ray diffraction analysis (XRD) identified magnesite as the primary reaction product, and under optimal conditions, 58.05% stoichiometric conversion of the silicate to carbonate was achieved in 60 minutes.