Cinética y Capacidad de Sulfatación de CaO en Lechos Fluidizados Circulantes para Captura de CO2

Resumo

[EN] Climate change mitigation will present a major challenge for mankind in the near future. The CO2 emitted from fossil fuel combustion is the principal source of greenhouse gases. CO2 capture and storage continues to be one of the most important options for mitigating climate change in the medium to long term scales. Among the emerging technologies for capturing CO2 from large-scale stationary sources, those based on CaO (Calcium Looping, CaO) in post-combustion processes have experienced rapid development in recent years. This is attributable to their enormous potential for reducing costs and energy penalties when compared to other more mature technologies. The possibility of avoiding the desulfuration stage by means of the simultaneous capture of CO2 and SO2 in the same reactor is another of their main advantages. Moreover, in processes of this kind, a synergy can be achieved if the CaO from the purge of the calciner is used as the source of the sorbent for desulfuration in the combustor. A kinetic study of the sulfation of CaO in operating conditions typical of CaL reactors has been carried out in this Thesis. For this purpose, a thermogravimetric device specially designed for conducting calcination/carbonation cycles was used. In addition, in an experimental pilot plant consisting of two fluidized circulating interconnected beds experiments on simultaneous sulfation, carbonation and calcination were performed in continuous mode. The results of these studies have been validated at larger scales by measuring in a thermogravimetric apparatus the sulfation rates and capacities of a sorbent obtained from a 1.7 MWt CO2 capture pilot plant located in La Pereda. The experimental data have been interpreted by means of a random pore model (RPM).