Reactive absorption of CO2 into Piperazine aqueous solution in a stirrer bubble column: Modeling and experimental

Abstract

The present work focuses on CO2 reactive absorption using Piperazine aqueous solutions in a stirrer bubble column. A stirrer bubble column has been applied for operating conditions, including CO2 partial pressures in the range of 16.0–35.2 kPa, stirrer speed in the range of 0–300 rpm and CO2 loading in the range of 0.01–0.3 mol CO2.mol Pz−1. The results reveal that the absorption reaction rate increases with increasing the CO2 partial pressure and Pz concentration. The film parameter increases with increasing the Pz concentration and decreasing the CO2 partial pressure. Experimental results show that mass transfer flux, overall mass transfer coefficient and removal efficiency of CO2 are varied in the range of (0.35–4.32)×10−6 kmol.m−2.s−1, (2.39–2.58)×10−6 kmol. m−2.s−1.kPa−1 and 65.5–82.1%, respectively. Hydrodynamic studies illustrate that gas holdup, gas-liquid interfacial area, and Sauter mean diameter increases with increasing CO2 partial pressure and decreasing Pz concentration. Also, it was found that gas holdup, Sauter mean diameter and interfacial area values obtained in this work are within the range of 0.06–0.076, 10–13 mm and 44.0–46.1 m2 m−3, respectively.