CO2 Sequestration by Mineral Carbonation: A Review

Abstract

The mineral sequestration, one of the methods of CO2 sequestration, is considered advantageous, as it not only facilitates permanent and leakage free storage of CO2 but also obviates the need for regular monitoring. Mineral sequestration involves the dissolution of minerals and subsequently carbonation of dissolved minerals. In the direct mineral sequestration all the processes occur within a single reactor, whereas in the cases of indirect mineral sequestration, they take place in separate reactors. The main aim of the present study is to investigate the efficacy of these mineral sequestration methods and examine their suitability for industrial application and ensuring environmental friendliness. For this purpose, literature pertaining to these methods was extensively reviewed, and observations made by several researchers were collected, collated and compared based on the various parameters such as reaction pathways, reaction kinetics and cost of the process. The process cost was found to depend on the type of the process, process parameters, input materials and additives. It was noted that the direct mineral sequestration suffers from the sluggish reaction kinetics, thereby becomes economically unviable. The success of direct mineral sequestration process is yet to be achieved despite research carried out for several years. The problem of sluggish reaction kinetics was overcome by using multi-steps indirect carbonation routes, where separate reactors were used for dissolution and precipitation processes. The indirect sequestration method was noted to be most efficient as it offered several advantages such as improved reaction kinetics and recovery of the market value of by-product due to the better quality control of the product. Hence, based on interpretation of an extensive review of literature it can be concluded that the indirect mineral sequestration may be a viable option to carry out the CO2 sequestration and may be proved as a guiding light to ensure the clean environment for future generation.