The Adsorption And Desorption Behaviour Of SO₂on Immobilized Ionic Liquid Research

SO2is one of the most serious air pollutants, especially in China.The currently dominant desulfurization technology, wet flue gasdesulfurization (WFGD), requires high cost and energy consumption,causes serious pollution and waste of water resources. Since there isessentially no potential space for WFGD improvement, it is desired todevelop efficient, economical and environmentally friendly SO2emissionreduction technique. Ionic liquids have been used in field of volatileorganic compounds and acid gas removal as a novel reaction medium inrecent years. It has shown a good application prospect. The study ofengineering theory is urgently required to form the realistic productivity.In this work, a new efficient selective absorption of SO2sorbentTetramethylguanidine ionic liquid was synthesized based on previousstudies. The liquid ion stability was tested at different temperatures andpressures. IL TMGL was immobilized on different size silica gel througha physical method of impregnation-evaporation to obtain different loadratios TMGL-SiO2. SO2adsorption and desorption experiments werecarried out to investigate the effects of various operating conditions, suchas temperature, particle size and load ratio, on SO2adsorption capacity.Breakthrough curves of SO2were measured through online detectiondevice of SO2, which was built in this laboratory. Breakthrough curveswere used estimate adsorption capacity and rate constant. The majorresults are summarized as the follows:(1)The adsorption capacity decreases with increased temperatures;adsorption capacity increases with increased initial concentration, the load ratioing and particle size.(2) Experimental data for absorption was fitted with Langmuirmodel under different operating conditions and the results indicate thatSO2absorption on ionic liquid conform to the Langmuir adsorption.(3) Yoon-Nelson model was used to identify the breakthrough curves.It gives the better results to predict the breakthrough time, which canprovide a reasonable basis for the process parameters for flue gasdesulfurization design and practice.