Study On Desulfurization Of Organic Thiophenic Sulfur In Gasoline With Extraction/Oxidation/Adsorption

With the acceleration of industrialization, environmental pollution has become animportant issue that restricts the development of society. SOx, the combustion product ofsulfur compounds in gasoline, is one of the main pollutants. Thus, developing new deepdesulfurization technology has become main challenge to the refining industries and to theresearch communications.This work aims to explore a new technology to remove sulfur from gasoline withextraction, oxidation and adsorption. The organic thiophene sulfide was first extracted fromgasoline by the method of extraction to avoid damage to the gasoline, and then desulfurizationwas conducted using oxidation and adsorption technologies in the extract phase.The effects of different extractants on extraction and desulfurization efficiencies ofgasoline were studied. The efficiency of acetonitrile as extractant was extensively examined.The optimal operation conditions at room temperature for using acetonitrile as extractant areas following: the extractant/water volume ratio is within the range of10:2~10:3, and theextractant/gasoline volume ration is within the range of3:5~4:5. Under the optimal conditions,the final recovery efficiency of gasoline is almost100%, and the desulfurization efficiency foronce extraction is about30%. GC-SCD was used to analyze the main components of testinggasoline. Model oil was chosen as research objectives to examine the extraction selectivity ofacetonitrile for the organic thiophene sulfides in gasoline. The result showed that theextraction selectivity follows the order: Thiophene> benzothiophene>2-methylthiophene.Oxidization kinetics of the thiophene sulfide compounds in acetonitrile was investigatedwith ozone as oxidant. Results showed that:1)thiophene sulfide compounds were oxidized byozone completely at room temperature and atmospheric pressure, and it’s reaction equationwas zero-order, The conversion efficiency of thiophene sulfide compounds increased withtemperature in the range of10~25℃, but decreased when temperature became higher than25℃;2) as oxyen flow-rate increased, the conversion efficiency of thiophene sulfidecompounds increased. Result of GC-MS analysis showed that oxidization products ofthiophene sulfide was to oxysulfide, that of benzothiophene sulfide was benzothiophenesulphone. Adsorption of Thianaphthene-1,1-dioxide in acetonitrile on activated carbons wasinvestigated. Results showed that the adsorption capacity of activated carbon for sulphone inacetonitrile followed the order of XFP01AC>higher surface AC>SY-11>SY-6, and theadsorption capacity of activated carbon was in propotion to its amount of surface acidfunctional groups;13X zeolite had no adsorption capacity toward thiophene andbenzothiophene in acetonitrile due to strong competing adsorption of acetonitrile. However,13X zeolite had adsorption capacity of thiophene and benzothiophene in octane.