A practical approach to CO2 sequestration: Reactions with high salinity water

Abstract

Carbon dioxide is known to be a major contributor to global warming and climate change and hence has an adverse effect on environmental sustainability. CO2 is emitted by various activities associated with industrial processes and the burning of various types of carbonaceous fuels such as coal, oil and gas. Over the past few years, there has been a considerable amount of interest in carbon capture and storage (CCS) as an option to mitigate the harmful effects of CO2 emissions. This study evaluates a new approach to the capture and sequestration of CO2 through reactions with high salinity water in the presence of an alkaline agent. Processes such as the Solvay process have been successful in utilizing the reactions of CO2 with ammoniated high salinity water to sodium bicarbonate. This process, however, suffers from several drawbacks such as inefficient contact mechanism and the need for the regeneration of ammonia as alkaline catalyst in the process. Such drawbacks have been addressed through developing a new, inert particles reactor system that offers efficient mixing and stable operation. At the same time, carbon dioxide is reacted with high salinity water in the presence calcium hydroxide instead of ammonia to provide the alkalinity needed for the reaction of CO2 and NaCl. The new process and reactor system were able to achieve high CO2 capture efficiency (up to 99%) and effective reduction in water salinity (up to 40%), while storing the CO2 in a stable solid form, namely sodium bicarbonate. The new process can utilize any alkaline solid waste and the inert particles reactor system can be used to capture CO2 from different sources such as natural gas or flue gas