Integration of MEA-Based Absorption with Fly Ash-Baesd Mineralisation for CO2 Sequestration from Flue Gas with Low Energy Penalty

Whilst the amine-based carbon dioxide (CO₂) capture suffers from high energy consumption of absorbent regeneration, the traditional CO₂ mineralization is constrained by the low reaction rate and low CO₂ removal efficiency. To overcome these problems, a novel process that integrates amine scrubbing, CO₂ mineralization and amine regeneration into one process has been developed in this study. The most commonly-used amine, monoethanolamine (MEA) was used to investigate the performance in CO₂ absorption, CO₂ mineralisation and amine regeneration by calcium oxide (CaO) and fly ash. The results show that CO₂ captured in MEA amine solutions was sequestered into precipitates at low temperature (40ºC) and the amine solutions were generated after mineral carbonation. MEA exhibited 1.5 tim higher cyclic capacity, compared with the traditional amine-based CO₂ capture. The performance stability of MEA in multicycle experiments was also investigated. The proposed novel process also exhibits other great advantages, i.e. great energy saving of absorbents regeneration and CO₂ compression, deep amine regeneration and simplification of amine process to avoid the geological CO₂ storage. In contrast to the traditional mineralization, the novel process greatly improves the carbonation rate and CO₂ removal efficiency. The results indicate that the competitiveness of IAM in carbon capture, utilisation and storage (CCUS) technologies and the great potential for industrial application using the calcium oxide containing waste such as fly ash and carbide slag. The potential utilization of the carbonated fly ash in blended cement was also discussed in this study.