The study of natural dolomite as a prospective material for CO2 capture employing a novel approach to the evaluation of breakthrough curves

Abstract

The capture of carbon dioxide (CO2) is a critical technology for addressing climate change and sustainability objectives. In this study, the performance of natural dolomite as an effective sorbent for repeated CO2 capture was evaluated. The results suggested that an optimal calcination temperature of 850 degrees C was beneficial for minimizing surface sintering of the dolomite, thereby facilitating effective decarbonation. Breakthrough curve analysis was conducted to evaluate the dynamic adsorption performance of dolomite at varying CO2 concentrations (10 %, 12 %, and 16 %). To assess the progress of gas adsorption onto regenerated dolomite, an innovative method of curve fitting using the modified Avrami equation was employed, which provided three essential parameters for the adsorption process: retention time, rate constant, and Avrami coefficient. A steady decrease in breakthrough time and adsorption efficiency was found to be correlated with sintering and surface area loss. The maximum CO2 adsorption capacity was achieved during the second or third cycle for all three measured CO2 concentrations; however, performance gradually deteriorated in subsequent cycles due to surface sintering and a reduction in specific surface area. TPD and BET analyses supported the conclusion that the surface area decreased with repeated regeneration, and the basic active sites were reduced.