VOCs Absorption By Emulsion Liquid Membrane-study On Optimization Of System Parameters And Demulsion

In this paper, research is focused on the three aspects. Firstly, the comparingstudy on the stability of emulsion liquid membrane(ELM) with different organics(petroleum ether and paraffin oil) and surfactants(T151 and T155) as oil phase andemulsifer respectly. Secondly, the study on separation of butyl acetate in modelindustry flue gas by emulsion liquid membrane. Thirdly, the study on the electrostaticbroken emulsion in ELM separation.The first part is the premise of the second in which some operating parametersmay affect the stability and the separation efficiency of ELM were investigated,including the concentration of surfactant, the ratio of emulsion and water, the rev ofstirrer. Experiments data showed that there were some kind of "critical value" forthose factors respectively. Under this critical condition, both the stability and theseperation efficiency of ELM were satisfying. For the emulsion system with petrolemether as oil phase and T151 as emulsifier, when the rev of stirrer was 3000rpm, theratio of oil and water was 1:1, the concentration of T151 was 6%, the ratio ofemulsion and water was 1:4, the rev of second stirring was 300rpm, both the stabilityof ELM and absorption efficiency of butyl acetate in model flue gas by ELM couldreach a high level. The critical condition for T155 was alike with little differences atconcentration(4%), rev of stirrer(4000rpm) and second stirring(400rpm). For theemulsion system with paraffin oil as oil phase, when the rev of stirrer was 3000rpm,the ratio of oil and water was 1:3, the concentration of surfactants was 4%(T151 andT155), the ratio of emulsion and water was 1:4, the rev of second stirring was 300rpm,both the stability of ELM and absorption efficiency of butyl acetate in model flue gasby ELM could reach highest level.The study of the electrostatic broken emulsion of ELM with different oil phaseincludes the two aspects, demulsion voltage and demulsion time. The results showedthat the demulsifier had optimal demulsion voltage and demulsion time, and thedemulsion efficiency of ELM with paraffin oil as oil phase was higher than thepetroleum ether one. The better oil-water separation results can be obtained when thevoltage is set above demulsion critical voltage.