Deep Desulfurization From Gasoline By Catalytic Oxidation In Emulsion System

Gasoline is oxidated for desulfuration with hydrogen peroxide as oxidant.Because of that oxidant is water soluble,oxidant can't contact with oil phase which contain sulfide.And it will lead to amplify the mass transfer resistance and reduce the mass transfer rate,at last,it will reduce desulfurization degree,make the oxidant wasteful,increase the cost of desulfuration.Phase transfer catalyst is combined with emulsion system in the experiment.With hydrogen peroxide as oxidant,and alkyl betaine as phase transfer catalyst,refined gasoline catalytically cracked gasoline and hydrogenated gasoline are catalyzed and oxidated for deep desulfuration in emulsion system.Investigating the conditions of the technology of oxidizing reaction,the most adaptive reaction condition and influencing regular pattern of the phase transfer catalyst are confirmed.It includes:the kinds of phase transfer catalyst,mass ratio of phase transfer catalyst and gasoline,molar ratio of the oxidant and phase transfer catalyst,rotate of speed emulsification,response time(the sum of emulsification time and standing time),the ratio of emulsification time and standing time.Making emulsion system combining with phase transfer catalyst and adding extraction process,the experiment removes the sulfured in the gasoline.The research results indicate the best desulfurization effect:the phase transfer catalyst is 1-Octadecanaminium,the mass ratio of phase transfer catalyst and gasoline is 0.01,the molar ratio of the oxidant and phase transfer catalyst is 3:4,the rotate of speed emulsification is 9000r/min,the emulsification time is 3min,the standing time is 6min,the extracting agent is N-Methyl pyrrolidone which volume fraction is 80%,the volume ratio of extracting agent and gasoline is 1:1,the extraction time is 20min.The sulphur content of refined gasoline is 244?g/g,21?g/g after desulfuration,and the desulfurization degree is 91.4%.The sulphur content of catalytically cracked gasoline is 314?g/g,27?g/g after desulfuration,and the desulfurization degree is 91.4%.The sulphur content of hydrogenated gasoline is 286?g/g,24?g/g after desulfuration,and the desulfurization degree is 91.6%.The sulphur content of the three gasoline reach the requirement of deep desulfurization after removing sulfur,and reach the standard of the national standard-under 50?g/g.After reclaiming the phase transfer catalyst,the desulfurization degree of refined gasoline is 91.8%,the desulfurization degree of catalytically cracked gasoline is 90.4%,the desulfurization degree of hydrogenated gasoline is 90.9%.The desulfurization degree is similar with the first time.It illustrates that:alkyl betaine that is used as phase transfer catalyst can be reused.