Removal/recovery of hydrochloric acid using Alamine 336, Aliquat 336, TBP and Cyanex 923

Abstract Solvent extraction of hydrochloric acid has been studied from solutions containing 185.42 g/L acid using Alamine 336, Aliquat 336, TBP and Cyanex 923 as extractants. Kerosene was used as the diluent. Extraction of hydrochloric acid increased with the increasing concentration of the extractants. For all the extractants studied, the species extracted into the organic phase appears to be associated with one mole of extractant. For Alamine 336, the McCabe–Thiele construction indicated the possibility of > 99.5% HCl extraction in two counter-current stages at A:O = 1:4. For Cyanex 923, the McCabe–Thiele construction indicated the quantitative extraction of HCl in four counter-current stages at the A:O = 1:5 phase ratio. The acid loaded onto Aliquat 336, TBP and Cyanex 923 could be easily stripped with water. But acid loaded onto Alamine 336 could not be stripped with water. The stripping efficiency was ∼ 12% with dilute acid and quantitative with 1 N NaOH for acid loaded onto Alamine 336.