Regeneration Of Spent Sulfuric Acid By Extraction Using Hydrophobic Ionic Liquids

Sulfuric acid alkylation process is one of the main processes for large-scale production of alkylate in the world.The biggest problem of this process is the disposal of sulfuric acid.Extraction method can be widely used and industrialized because of its low cost and low energy consumption.In view of the broad and adjustable dissolving capacity for target substances,hydrophobic ionic liquids were used in this paper to extract the acid soluble oils(ASO)from waste acid to realize its regeneration.Firstly,the components of waste sulfuric acid were analyzed,especially a series of characterization analysis including the FT-IR,GC-MS,UV,GPC,EL for the key components ASO in spent acid.Secondly,five different types of imidazolium-based ionic liquids(ILs)and their mixtures were selected as extractant for extraction and separation of ASO from spent sulfuric acid,including[Bmim]PF6,[Hmim]PF6,[Omim]PF6,[Bmim]Tf2N and[Bmim]BF4,and target ionic liquids was synthesized and characterized.Thirdly,extraction abilities of different ionic liquids for ASO were investigated and extraction conditions were optimized.Finally,the interactions between ionic liquids and ASO were studied by molecular simulation.