Study On The Properties And Reaction Performance Of The New C₄ Alkylation Catalysts

In recent years,the alkylation reaction of isobutane and butenes（C₄alkylation）has attractedmoreattentions.Conversional liquid acid catalysts have many disadvantages such as environmental pollution and large acid consumption.This thesis combines the advantages of both ionic liquid（IL）catalysts and solid acid（SA）catalysts,Andwe synthesized a seriesof new ionic liquid/solid acid catalystsfor catalyzing C₄ alkylation.These catalysts are prepared by dispersing SO₄^2-/ZrO₂（SZ）into mesoporous MCM-41,and then fixing the ionic liquid on the solid support by impregnation.The acceptor properties of chlorinated metal salt mixed ionic liquids for isobutane-butene alkylation reaction were studied.The chlorinated metal ionic liquids are prepared by mixing metal chloride with triethylamine hydrochloride salt or 1-butyl-3-methylimidazole chloride in various molar ratios.Using triethylphosphine oxide as a probe,the Gutmann receptor number（AN）of the catalyst was determined.And quantitatively measure the Lewis acidity of the mixed metal chlorate ionic liquid.First,we prepare a solid acid with added metal ions,and its acidity changeswasinvestigated.Inaddition,we studytheacidityoftheionicliquidand combine it with solid acids to catalyze the alkylation of isobutane and 2-butene.Second,the transition metal compound promoter has a certain improvement in the selectivity of ionic liquid catalytic alkylation.Based on previous studies,we tried to add different transition metal compound promoters to different alkylation catalytic systems,Observewhether similar results will be obtained.An alkylation evaluation experiment was conducted to compare the catalytic performance of each catalyst.Third,the synthesized new catalyst was characterized by X-ray diffraction,nitrogen adsorption isotherms,infrared spectroscopy,magic angle rotation solid-state NMR(²⁹Si/³¹P MAS NMR)and temperature programmed NH₃ desorption,The results show that the zirconia sulfate is loaded in the inner pores of MCM-41 mesopores and ionic liquids play an important role in maintaining the activity of synthetic catalysts.Let the reaction proceed both in batch reactor and continuous stirred tank reactor（CSTR）.The catalytic behavior of the new IL/SA catalyst was studied at25°C.Itwas found that 5gIL/SZ-Zn@MCM-41 catalyst in CSTR can continuously catalyze alkylation reaction for more than240minutes.The amount of trimethylpentane（TMP）and octane number（RON）of the obtained alkylate reached 83.3wt%and 98.5wt%respectively.Finally,this thesis studies the relationship between the Lewis acidity and catalytic selectivity using the AN value.The optimal AN value for the C₄ alkylation reaction is about 93.0.The correlation between the number of receptors and the morphology of the mixed metal chlorate ionic liquid was studied.