Synthesis of Iron-Based Chemical Looping Sorbents Integrated with pH Swing Carbon Mineral Sequestration

摘要

The previously developed pH swing carbon mineral sequestration immobilizes the gaseous CO_2 into a thermodynamically stable solid, MgCO_3, using Mg-bearing minerals such as serpentine. This mineral carbonation technology is particularly promising since it generates value-added solid products: high surface area silica, iron oxide, and magnesium carbonate, while providing a safe and permanent storage option for CO_2. By carefully controlling the pH of the system, these solids products can be produced with high purity. This study focuses on the synthesis of iron oxide particles as a chemical looping sorbent in order to achieve the integration between carbon capture and storage technologies. Since the solubility of Fe in aqueous phase is relatively low at neutral pH, the effect of the weak acid and chelating agents on the extraction of Fe from serpentine was investigated. The synthesized iron-based chemical looping sorbent was found to be as effective as commercially available iron oxide nanoparticles at converting syngas into high purity H_2, while producing a sequestration-ready CO_2 stream.