| With the development of ethylene industry, comprehensively processing of theby-products china is important to increase the process efficiency.In our country,naphtha is the main raw material used for ethylene production, and the fraction of C9 can reach up to 12.5% of product output.Most of the fractions are burned as fuel,just a small of which are used for producing petroleum resin.In recent years,although the utilization C9 fraction has been paid more and more attention,both theinvestment and technology development are not sufficient. Comprehensiveutilization of C9 fraction is of great significance for fully utilizing the resources andthe development of speciality petrochemicals for modern petroleum processingcompanies. In this paper, C9 petroleum resin with high softening point was preparedby carbenium ions polymerization process of C9 fraction using Al Cl3/ion exchangeresin as the catalyst. Distillate with low olefin content was prepared by olefinremoval of C9 fraction using a C2H4Cl2/Ti Cl4 catalyst system. FT-IR,1HNMR andGPC were employed to investigate the structure of petroleum resin and the influenceof reaction conditions on the polymerization.The results provided theoreticalsupport for the further processing of C9 fraction.Supported Al Cl3 catalyst was prepared by ion exchange process using sulfonicacid cation exchange resin as the supporter. The effects of solvent,temperature, time,mass ratio of ion exchange resin to Al Cl3 on the aluminum loading of solid catalystwere investigated. The effects of Ion exchange reaction condition on the aluminumcontent of Al Cl3 solid catalyst and structure was determined. When the solvent wascarbon tetrachloride, temperature was 72℃,mass ration between Al Cl3 and ionexchange resin was 1:1, time was 10 h, and post-treatment followed the way ofdeionized water-ethanol-deionized water washing, supported Al Cl3 catalyst onsulfonic acid cation exchange resin with 2.21% of aluminum was confirmedobtained.It was a strong proton acid catalyst by FT-IR qualitative analysis,FT-IRpyridine adsorption analysis and acid strength measurements,respectively.The Al Cl3/ion exchange resin catalyst was sed in the polymerization of C9 fraction for the first time.In order to determine the optimum C9 fractionpolymerization condition,softening point, yield and the molecular weight of resinwere chosen as the reference index.Both FT-IR and 1HNMR were employed toanalyze the structure of the C9 petroleum resin product.When the mass fraction ofAl Cl3 catalyst was 2.5%,reaction temperature was 50℃ and reaction time was 6h,light yellow petroleum resin with softening point of 100.1 ℃,yield of 42.7% andmaximum Mw of 948 was obtained. FT-IR, 1H NMR analysis showed that,compared to the polymer obtained from Al Cl3 catalytic polymerization, the oneobtained from C9 fraction polymerization induced by solid catalyst had longer mainbackbone chain and lower degree of unsaturation.C9 fraction polymerization mechanism and dynamic characteristics wereinvestigated for the relationship between the molecular weight of products,iodinevalue and time. The influences of reaction temperature, catalyst dosage and reactiontime on the polymerization were analysed. Gel-permeation chromatograph(GPC)of polymer showed that dispersion coefficient(D) of C9 petroleum resin wasbetween 1.4 and 20,and the polymerization of C9 fraction belonged to carboniumion chain polymerization,molecular weight of the product follow to normaldistribution.The ln(Im0/Im) variation as a function of time was investigated by usingiodine value as the representing olefin concentration. The experimental resultsshowed that the polymerization of C9 fraction catalyzed by Al Cl3 catalyst fitted thecharacteristics of first order reaction. The relationship between the reactiontemperature, catalyst dosage and ln(Im0/Im) variation suggested that chaininitiation polymerization was the essence of C9 fraction polymerization.Colorless solvent of naphtha was prepared for the first time by olefin removelreaction of C9 fraction polymerized using C2H4Cl2/Ti Cl4 catalytic system.C2H4Cl2/Ti Cl4 catalytic system has the advantages of smaller dosage and shorterreaction time.When C2H4Cl2 dosage was 0.2%,Ti Cl4 dosage was 1.1%,2,6-dimethyl-Pyridine dosage was 0.9%, reaction temperature was 50 ℃ and reaction time 3h,colorless and transparent solvent naphtha with 0.72% of olefin centent was obtained,with boiling point being lower than 200 ℃, yield of 30.79% and olefin removalyield up to 92%. It could be separated into three distillates and bottom oils with100~130 ℃,131~140 ℃ and 141~198 ℃ according to the boiling range.Additionally, it can be used as gasoline blending, rubber and paint solvent naphthaaccording to the component and quality index, and the bottom oil could be used asboiler fuel.Dynamics and mechanism of C9 fraction olefin removel reaction induce byC2H4Cl2/Ti Cl4 catalytic system is proposed. Experimental results showed thatchloralkane as coinitiator was necessary in the olefin removal reaction catalyzed byTi Cl4, and the ratio of [C2H4Cl2]/[Ti Cl4] was less than 1, the C9 fraction olefinremovel reaction can be characterized by first-order kinetics. |
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