Study on HCl removal by glycerol in a rotor-stator reactor and desorption of HCl

Abstract

The emission of hydrogen chloride (HCl) flue gas poses threats to environment and human health, and the removal of HCl from flue gas has attracted much attention. In this work, HCl removal from a simulated flue gas by glycerol was conducted by employing the rotor-stator reactor (RSR) as an absorber. The effects of rotational speed, glycerol flow rate, gas flow rate and glycerol temperature on the removal percentage of HCl, overall gas-phase volumetric mass transfer coefficient and height of mass transfer unit were investigated. With the increase of HCl concentration in the inlet gas from 700 mg/m3 to 2400 mg/m3, the removal percentage remained about 94.5%. Then the mechanism of the HCl absorption by glycerol was investigated, and it was revealed that this process was dominated by physical absorption. Experiments on HCl desorption from glycerol were carried out at different temperatures, and it was found that there was almost no HCl left after glycerol was desorbed at 170 °C for 40 min. After five cycles, the absorption capacity of glycerol for HCl was almost constant. These results indicate that glycerol is a good absorbent for HCl removal from flue gas and the recovery of HCl dry gas.