Optimum operation condition of fluidized-bed homogeneous crystallization technology for the recovery of carbon dioxide captured in flue gas

Abstract

The decarbonization of industry, particularly in "hard-to-decarbonize" sectors like combustion plants, poses a significant challenge due to the limited availability of low-carbon options. Carbon capture, utilization, and storage (CCUS) offers a promising solution to this challenge. Chemical precipitation is one method of converting CO2 into precipitated mineral carbonates, which can be stored and converted into valuable materials. This study explores fluidized-bed homogeneous crystallization (FBHC) technology for recovering carbonate from simulated CO2-enriched flue gas, resulting in stable calcium carbonate granules. Factors such as pH, carbonate concentration, reactor type, and reactants significantly impact carbonate removal and crystallization efficiency. Optimal conditions were found at 0.086 M input carbonate concentration, pH 9.0, and using a two-stage reactor, achieving 99.9 % removal and 93.2 % crystallization efficiency. Potassium-based absorbents yield higher crystalline intensity and larger granules compared to sodium. X-ray diffractometry confirms the composition of calcium carbonates, demonstrating FBHC's effectiveness for CO2 capture and storage. Utilizing calcium carbonate granules for carbon dioxide sequestration can potentially reduce emissions, pending resolution of investment and feasibility challenges.