| Nowadays the main desulphurization technology of fuel oil used in refinery industry is the hydrogenation desulphurization (HDS). However, operation of the available HDS is hard to control and some aromatic S-compounds, including thiophenes, bezothiophenes, dibenzothiophenes and their alkylated derivatives could hardly be removed by the HDS technique. In this thesis, ionic liquids (IL) have been studied on extraction desulphurization (EDS) and oxidation desulphurization (ODS). Relative to HDS, EDS and ODS have a good many excellencies, such as technologic process simple ness, a little of investment of equipment, mildness of reaction condition etc. It is a new technology of desulphurization.In this thesis, studied on EDS and ODS of fuel oil by IL. The major work and innovative results of this dissertation are as follows: (1) A series of imidazolium-based ionic liquids have been synthesized, and the purities and physical properties were determined by IR. The results showed that the qualities of the synthesized ionic liquids were up to the expectant requirements; (2) The extracted properties of the sulphides in fuel oils by imidazolium-based ionic liquids were studied. The results showed that the desulphurization efficiency to reach 62 % in condition of 50℃, 30 minute and the rate of solvent and oil being 1:2, the rate of catalyst and oil being 1:2 . Further more, equation of kinetics and oxidation-extraction equation of kinetics were educed by stair model of reaction. In order to provide a basis for industrial applications, the physical properties of ionic liquids like density and viscosity were tested. It provides important parameters to techniques of experiment. (3)The ionic liquids were recovered with the extraction method and screening out the better solvent used in recovery. In addition, ionic liquids also have better effect in desulphurization that used several times and the ionic liquids recovered still have a very good desulphurization effect, there is only a small decline in the desulphurization rate. (4)The light oil was extracted with fresh ionic liquids for several times that was investigated ,when extracted for four times that the desulphurization effect is reached 10 ppm. (5)The mechanism of oxidative desulphurization was studied, on the effect of oxidant that thiophenes exists in oil were changed into sulfone or sulfoxide which have a stronger polarity, which were more extracted by ionic liquids. (6)The oxidative oil analysised by GC and GC-MS has been proved that thiophene had been changed into Thiophene-sulfone and N-octane isomers had generated.It was indicated that the content of sulfur can reduced below 50 ppm by EDS and ODS, and reached to EuropeⅣ, that satisfies the developed oil-requirements of our country in the future.
|
PDF Full Text Request