Synthesis and characterization of microfibrous media supported K ₂CO ₃ for CO ₂ capture

Current commercial CO ₂ removal technology in the manufacture of ammonia and syngas utilizes aqueous K ₂CO ₃ solvent. However, the use of the solvent requires a large reactor volume. CO ₂ capture capacity is enhanced while significantly increasing bed utilization efficiency and reducing overall system weight and volume by introducing microfibrous media. Microfibrous media bring advantages to the process by combining the use of small support particulates to promote K ₂CO ₃ utilization and the use of microfibers to promote high contacting efficiency and high accessibility of K ₂CO ₃ while minimizing the pressure drop. K ₂CO ₃ sorbents supported on high surface area activated carbon particulates (ACP) of 100-250 um (dia.) are prepared by pseudo-incipient wetness at different K ₂CO ₃ loading. The drying temperature is maintained around 100-120°C. It is found that K ₂CO ₃ loading negatively correlates to K ₂CO ₃ utilization. An analysis of impregnated salt properties and their structural changes during CO ₂ adsorption is investigated by x-ray diffraction spectroscopy (XRD). Based on XRD results, the presence of K ₂CO ₃ phase appears at K ₂CO ₃ loading of 30 wt.% as shown in Figure 1. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is then utilized to confirm the presence of K ₂CO ₃ at loading below 30 wt.%. The thermal stability and crystallization temperature at elevated temperature (35 -500°C) are determined by differential scanning calorimetry (DSC) as shown in Figure 2. The surface morphology of sorbent surface is examined using scanning electron microscopy (SEM).