Regeneration of heat stable salts-loaded anion exchange resin by a novel zirconium pentahydroxide [Zr(OH) 5 − ] displacement technique in CO 2 absorption process

Abstract

Abstract In the CO2 absorption process, heat stable salts (HSS) have been reported to be a major cause of operational problems, such as excessive foaming, corrosion, amine loss, and capacity reduction. Ion exchange technology has been the most effective and economical way for the removal of HSS. However, the disadvantage of this technology is its low regeneration efficiency. This study attempted to improve the low regeneration efficiency of anion exchange resin loaded with HSS by using a novel zirconium pentahydroxide (ZrOH5−) displacement technique. The experimental results showed, in the batch system, that the most effective potential metal-hydroxide regenerant, Zr(OH)5−, exhibited an efficiency that is 15.2% higher than for conventional NaOH, and in the continuous system, Zr(OH)5− had an efficiency that is 28.0–17.8% higher for 1.5–5 bed volume (BV). The differences of the BV corresponded to the breakthrough point for the initial breakthrough and after the 1st and 2nd regenerations were only 1.5–3.9%, which means that there was no significant deterioration of the resin’s performance by Zr(OH)5− regeneration. The mechanism of the general ion exchange steps as well as the regeneration by Zr(OH)5− was determined by performing an FT-IR analysis. These results indicate that the novel Zr(OH)5− displacement technique improves the low regeneration efficiency of the ion exchange process.