Study On Hydrogen Chloride Absorption By Glycerol In A Rotor-Stator Reactor And Desorption Of Hydrogen Chloride

The emission of hydrogen chloride(HCl)flue gas is of concern as it poses a threat to the environment and human health.HCl in flue gas is usually absorbed to convert it into other substances for disposal,but HCl is rarely recovered as the dry gas for utilization even if the HCl dry gas has found wide applications in different fields.To address this issue,this thesis studied the absorption of HCl by glycerol in a rotor-stator reactor(RSR)and the desorption of HCl from glycerol,in an attempt to find an efficient method for the treatment of HCl flue gas and recovery of HCl dry gas.The main results are as follows.1)The mechanism of hydrogen chloride absorption by glycerol was investigated,and it was found that the process was physical and chemical absorption at the same time,and the physical absorption accounted for about 93.2%.The bond lengths,interaction energies and total charge densities of hydrogen bonds between glycol,diethylene glycol,glycerol and HCl were compared by molecular simulations,and it was found that the hydrogen bonds formed between glycerol and HCl were strong.For the chemically absorbed fraction,the reaction product was determined by gas chromatography analysis to be mainly 3-chloro-1,2-propanediol.2)The absorption of HCl in a simulated flue gas by glycerol in the RSR was studied.The effects of rotational speed,glycerol volumetric flow rate,gas volumetric flow rate,glycerol temperature and HCl loading in glycerol on the absorption rate of HCl were investigated.The absorption rate maintained at about 94.5%as the HCl concentration in the inlet gas increased from 700 mg/m~3 to 2400 mg/m~3.In terms of price,HCl absorption rate and HCl dry gas recovery,glycerol was found to have the best comprehensive performances compared to water and deep eutectic solvent.The expressions for the total gas-phase volumetric mass transfer coefficient and height of a transfer unit in HCl absorption by glycerol in the RSR were derived,and the effects of rotational speed,glycerol volumetric flow rate,gas volumetric flow rate,and HCl concentration in the gas on the total gas-phase volumetric mass transfer coefficient and height of a transfer unit were investigated.3)The desorption of HCl from glycerol at different temperatures was conducted,and it was found that HCl was almost totally removed from glycerol when glycerol was desorbed at 170°C for 40 min,and 20 min was determined as a suitable desorption time.The effects of stirring speed,HCl loading in glycerol,and rich liquid mass on the desorption performance were investigated.After five cycles,the absorption capacity of glycerol for HCl remained almost unchanged,indicating that glycerol had a good stability.These results showed that glycerol not only has a high absorption rate of HCl in flue gas,but also can achieve the recovery of HCl dry gas through desorption.