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Study On Catalysts For Catalytic Amination Of Diethylene Glycol With Tertiarybutylamine

Posted on:2020-12-04Degree:MasterType:Thesis
Country:ChinaCandidate:X HaoFull Text:PDF
GTID:2381330575978902Subject:Physical chemistry
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The organic amine was introduced with sterically hindered groups can effectively improve the selective desulfurization performance.Tertiarybutylaminoethoxyethanol(TBEE)has been proved to be a more efficiently desulfurization,the performance of desulfurization was superior to methyl diethanolamine(MDEA),especially in selective removal of a high proportion of carbon dioxide/ hydrogen sulfide(CO2/H2S)and high acid gas loading,the solvent of TBEE has obvious advantages.Using diethylene glycol(DEG)and tertiarybutylamine(TBA)as reactants to catalytic amination synthesize tert-butylaminoethoxyethanol(TBEE).Compared with using reactants of 2-chloroethoxyethanol and tert-butylamine,it has obvious advantages in low cost,simple operation and optimization of environmental problems.The green and environment-friendly synthesis route and the excellent performance of TBEE in desulfurization make the study of the efficient synthesis of TBEE more urgent.For the amination of diethylene glycol with tertiarybutylamine,the design and optimization of the catalysts system,the selection of the reaction device and the optimization of the reaction conditions are very important.In this paper,amination of diethylene glycol with terttiarybutylamine over highly effective catalysts in the fixed-bed reactor studied the catalyst and reaction system,combined with the characterization and the results of reaction evaluation,investigated the relationship between the structure and reaction performance,the reaction conditions were further optimized.The main studied contents of this paper are as follows:1.For the nickel-silica catalysts system,the amination of diethylene glycol with tertiarybutylamine was applied in the fixed-bed reactor,the Si O2 and catalysts precursor were no reactive.Catalysts with a loading of 20% nickel have better catalytic amination performance,combined with the kinds of characterization: XRD,H2-TPR,N2-adsorption,NH3-TPD,the Ni0 was the active species in the amination of diethylene glycol with tertiarybutylamine.2.The catalysts treatment conditions were investigated: the effect of the calcination temperature and the reduction temperature of the catalysts on the reaction performance.The results showed that different calcination temperatures on the reaction performance were investigated.The results showed that different calcination temperatures affect the interaction between nickel species and the support and further influence the reduction of Ni2+.The higher calcination temperature makes Ni2+ was hard to be reduced,resulted the conversion of DEG was lower,the suitable calcination temperature was 400?;with the increase of reduction temperature,the reduced Ni0 content gradually increased,also the catalytic amination reaction performance increased.The results further proved that the active species was Ni0.3.The amination of DEG with TBA to synthesize TBEE over supported nickel catalysts with different supports prepared by incipient wetness impregnation,the results showed that the interaction between different supports and nickel species affected the reduction of nickel,and thus affected the amination performance of diethylene glycol and tertiarybutylamine.At the same time,the selectivity to TBEE was also affected by the different acid and base of catalysts prepared by different carriers,the strong acidity promote the TBEE dehydrate to by-product TBM,makes the selectivity to TBEE decreased.4.We investigated the influence of catalysts which the preparation methods and the addition of copper on the reaction performance.The results showed that the activity of the nickel-based catalyst was higher than that of the copper-based catalyst,while the selectivity to TBEE for the copper-based catalyst was better than that of the nickel-based catalyst.Introduced a small amount of Cu into the nickel-based catalyst to improve the selectivity to TBEE in the amination process.The catalyst with 1%Cu has the highest yield of TBEE.5.The reaction conditions for the amination of DEG with TBA to synthesize TBEE in the fixed-bed reactor was further optimized,investigated the effects of temperature,H2 pressure,LHSV,linear velocity and the ratio of reactants.The best reaction conditions were: the reaction temperature was 250?,the reaction pressure was 2MPa,the ratio of reactants n TBA:n DEG was 2:1,1.5m L of the 20%Ni/Si O2 catalyst,the linear velocity was 3m L.h-1 and the LHSV was 1h-1,the conversion of DEG was 49.4%,the selectivity to TBEE was 83.3%.6.Also the amination of diethylene glycol with tertiarybutylamine was evaluated in batch reactor,investigated the influence of Ni contents and the reduction temperature: with the increase of Ni,the conversion of DEG was increased and the selectivity to TBEE show the trend of increased first and then decreased;Also the conversion of DEG and selectivity to TBEE increased first and then decreased with the reduction temperature improved,the results further proved that the active species was Ni0.The catalytic amination of DEG with TBA in the batch reactor,the suitable reaction temperature was 230?.
Keywords/Search Tags:diethylene glycol, tertiarybutylamine, amination, nickel-based catalyst, fixed-bed reactor
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