Optimization of CO2 Adsorption on Solid-Supported Amines and Thermal Regeneration Mode Comparison

摘要

For improving the CO_(2) adsorption capacity of solid-supported amines, five commercial porous supports have been selected and impregnated with tetraethylenepentamine (TEPA), and their CO_(2) adsorption performances have been evaluated using a fixed-bed reactor coupled with mass spectrometry. For solid-supported amines, CO_(2) adsorption capacities coincide with the texture characterization of the adsorbent supports (mesoporous alumina, montmorillonite, silica gel, porous resin, MCM-41 molecular sieve), and the optimum TEPA loading amount is mainly affected by the pore volume. The mesoporous supports were found to be more conducive to uniform loading of organic amine, with more than 370 mg/g CO_(2) adsorbed per unit TEPA. Other components in flue gas, especially H_(2)O, favor CO_(2) adsorption on solid-supported amines. SO_(2) inhibited the CO_(2) adsorption, which was mainly attributable to the strong and irreversible binding of SO_(2) on some amine sites. NO had little effect on CO_(2) adsorption. Thermal stabilities of solid-supported amines have been tested based on thermogravimetry curves, and the main weight loss peak for TEPA appears at 513 K for solid-supported amines. Linear and step regeneration modes have been compared, revealing that the temperature for step regeneration is 37 K lower than that for the linear regeneration mode. Moreover, the desorption peak area for the step regeneration mode is 20% higher than that for the linear regeneration mode, indicating that the step regeneration mode can be used in practical applications, to reduce energy consumption during regeneration.