Retrieval of CO2 from a carbonate solution for its sequestration by a novel electrochemical decarbonizing and ingathering method

Abstract

Many attempts at CO₂ recovery and sequestration have been made in recent years. The use of an electrochemical decarbonizing and ingathering method exhibits the ability to segregate targeted ions absorbed in a dilute solution. However, because of the low conductivity of the dilute solution, a great part of the energy is consumed to overcome the internal resistance. In this study, an “electro-dynamic inspissation (EDI)” system was introduced to examine the retrieval of carbonate ions from a sodium carbonate solution. The addition of an ion exchange resin serving as a conductor in the EDI device provides a new way to enable CO₂ recovery from the concentrated stream; thus, a purified CO₂ stream was obtained. The properties of the EDI system were characterized in detail, addressing its recovery effectiveness and providing a cost evaluation. The results indicate that EDI performs well, with the current efficiency reaching 75% and the energy consumption calculated as 1.41 MJ kg⁻¹ of CO₂ captured. This system is an alternative to most traditional technologies, such as amine absorption/thermal desorption.