Study On The Preparation Of Amine Ionic Liquids And Their Application In The Process Of Desulfurization

The atmospheric pollution is increasingly serious with the rapid development of national economy,and the control of SO₂ pollution has become a top priority.Traditional desulfurization technology has some disadvantages: Causing corrosion of equipment,producing waste of liquid and residue,resulting secondary pollution to environment and the waste of sulphur resources.Ionic liquids have attracted the attention of many scholars because of their excellent characteristics,such as negligible vapour pressure,high boiling point,high stability,good desulfurization efficiency and regeneration performance.But the disadvantages of high viscosity and cost of ionic liquids limit their application in industry.Immobilization of Ionic liquids on porous materials or mixed with other solvent can enhance the desulfurization effect and solve these problems.In this paper,two kinds of ionic liquid,trioctylamine hydrochloride and trioctylamine sulfate,were synthesized and characterized by FT-IR,1H NMR and TG.The desulfurization performance of the ionic liquids were investigated.The saturated absorption capacity was 0.250 g SO₂/g IL（1.763 mol SO₂/mol IL）for trioctylamine sulfate and 0.357 g SO₂/g IL（2.174 mol SO₂/mol IL）for trioctylamine hydrochloride,respectively.After six continuous adsorption-desorption cycles,the absorption performance of the ionic liquids remain invariant,which illustrate that the ionic liquids have good reuse performances.The ionic liquids synthesized in this paper still have good absorption effect for the gas with low concentration of SO₂.When SO₂ concentration is 0.2%,the saturated absorption capacity was 0.053 g SO₂/g IL for trioctylamine hydrochloride and 0.037 g SO₂/g IL for trioctylamine sulfate,respectively.Binary systems of IL-DMSO were given by mixing DMSO with ionic liquids,and desulfurization performance of the binary systems were investigated.The desulfurization performance of the binary system is greatly strengthened than that of pure ionic liquid.At25 ℃,the absorption capacity can be as high as 1.024 g SO₂ /g IL-DMSO with the ratio of DMSO and trioctylamine hydrochloride increased to 4:1,which is better than any of the two.And the binary system has good regeneration performance,it can be reused many times.Ionic liquids were immobilized on porous silica gel with the impregnation method.The pore structures were analyzed,and it was found that silica gels immobilized ionicliquid have abundant pore structure.The desulfurization performances of ionic liquids supported on silica gel were studied.Under 25℃,the saturated adsorption capacity can be1.388 g SO₂/5g SiO₂ with the carrier content of trioctylamine hydrochloride increased to0.9:1,which is more than twice to the adsorption quantity of blank silica gel.After recycling 7 times,the adsorption performance of immobilized ionic liquids on silica gel basically remain unchanged due to their good reuse performance.