Mechanism And Technology Of Absorption Of SO₂ By Aqueous Tetraalkyl Ammonium Chloride Solution

SO₂ is one of main of air pollutants.The wet desulfurizationies is a FGD technology widely used the most worldwide at present.Ionic liquids,as a green desulfurization agen,have been widespread concern.The SO₂ absorption capacity of aqueous caprolactam-tetraalkylammonium halide ionic liquids?CPL-TAAX ILs?solution is excellent.Also the SO₂ absorption capacity of aqueous tetraalkylammonium halide?TAAX?solution is excellent,and the technology of absorption of SO₂ by aqueous TAAX solution is more simple than that of the technology of absorption of SO₂ by aqueous CPL-TAAX ILs solution.So it is important to know the mechanism and processes of SO₂ by aqueous TAAX solution.To explore the interactions between SO₂ and tetraalkylammonium halide,the influences of temperature,the concentration,length of alkyl chain and halide anion on the solubility of SO₂ in the tetraalkyl ammonium halide aqueous solutions were investigated.The components of the upper and lower of the solution concentrations of the mixtures of the tetrabutylammonium bromide and SO₂ were measured.The solutions were characterized by Infrared Spectroscopy?IR?and Raman spectra were used to characterize the solution.The viscosity and surface tension of aqueous TAAX solution were measured,also the recycling of TBAB and SO₂ were studied,the influence of concentration,gas flow rate and gas velocity were tested,and the best process parameters was got.The results show that: a phase separation occurred when SO₂ was introduced into some aqueous TAAX solution.The solubility of SO₂ in these solutions increased with the corresponding decrease in temperature and increase in the length of the alkyl chain,At lower temperatures?293.15K-304.59K?,the effects of the halide anion for descending counts of the solubility of SO₂ is Br > F > Cl.However,the solubility of SO₂ in the aqueous TAAX solutions with the halide anions follows the order F > Br > Cl from 304.59 K to 317.15 K.The stratified temperature points increased with a corresponding increase in the length of the alkyl chain and weakened in the electronegativity of halogen atom.The upper layer was a colorless aqueous phase that was composed mostly of water with a small amount of tetraalkylammonium halide and SO₂;the lower layer was yellow,clear and transparent,and it was composed mainly by the majority of the tetraalkylammonium halide and SO₂ with a small amount of water.The optimum process parameters under experimental conditions is that: concentration is 3%,gas flow rate is 1L/min and gasconcentration is 230-240 ppm,the maximum of absorption efficiency can be up to 91%.