Feasibility study on CO2 capture and storage in silicate substrates

The increasing CO2 concentrations in the atmosphere are attributed to the rising consumption of fossil fuels for energy generation. Mineral carbonation technologies methods are needed to prevent the global warming bellow 2ºC at the end of this century proposed in the Paris summit 2015. Carbonates mineralization of peridotites and serpentines can be enhanced in order to develop a significant method to safety storage CO2. These minerals have been proved to have higher affinity towards sinking of CO2. The goal of this thesis is the feasibility study of the carbonation reaction in typical mantel peridotites and serpentines. Specific experimental conditions were defined by reproducing the ones that gave the greater CO2 uptake with lower energy required cost, published at Kelemen and Matter, 2008. The samples where grounded to powder and exposed to a gas solid interaction at 185ºC and 1 bar of CO2 pressure plus atmospheric pressure for 2 hours. Under these conditions, all the samples had an increase in the carbonates proportion and it was clearly determined by using the following methods: powder XRD, FTIR transmission and acid triggered de-carbonation. FTIR results revealed clearly the changes caused by the carbonation reaction, giving the most accurate carbonation formation response. The latter also revealed qualitatively the increase of magnesite proportion in all the samples. The acid triggered experiment results revealed that the CO2 uptake by mineral carbonation reached a maximum value of 4%. Nevertheless, any of the methods could give a quantitative precise carbonation rate. The peridotites samples in all methods show a clear carbonation trend. The comparison between the peridotites samples composition and the carbonation rate estimated revealed the inverse relation of Mg# and Ca# towards CO2 uptake. At higher Mg# greater the carbonation rate. The Dunite sample (LT-1) carbonated the most out of the peridotites samples, which is the sample that has the highest Mg# and the lower Ca#. XRD results reveal that all the peridotites samples had calcium carbonate formation. Serpentines showed complex results that can be attributed to their mineral and compositional complexity. El incremento de la concentración de CO2 en la atmósfera es atribuido al elevado consumo de combustibles fósiles para la generación de energía. Las tecnologías de carbonatación mineral son necesarias para prevenir que el calentamiento global supere los 2ºC para el final de este siglo, propues