Research On The Process Of C₄Alkanes To Olefins In Fixed-bed Reactor

Light olefins, as a key organic chemical raw material, play a very important rolein the petro-chemical industry. Due to the consumption of isobutene in fuel additivesand other applications, the demand grows up year by year. Traditional raw isobuteneresources cannot satisfy this huge demand and there exists an big gap between therequirement and supply of isobutene. Whereas China is relatively rich in the supply ofraw isobutane that is consumed as civil fuel, LPG. The deep processing and utilizationof the raw isobutane is still on its first step. It is very significant to research anddevelop an effective process by dehydrogenation of isobutane to isobutene in order toextend and supply of isobutene and improve the economic value of the raw isobutane.Based on the comprehensive investigation and analyses of the scientific andtechnical literatures and relative references about the processes and catalysts indehydrogenation of alkanes chiefly in isobutane, some catalyst carries and formulaewas screened and made out with the characteristics of high-coversion andhigh-selectivity. Furthermore primary designs of industrial dehydrogenator andflowsheet were having carried out. The research in this thesis was divided into fourparts:The first part was concentrated on the analysis of the catalysts and the processesabout isobutane dehydrogenation in order to understand the trends of research anddevelopment in this aspect.The second part was focused on the decision of experimental methods, thedesigning of experimental progress and the setup of laboratory equipment, also,including the adoption of the auxiliary analytical method and instrument，GC beingused in the research.The third part maintains a very important part in this work. Through the scale-upexperiments, many parameters were decided consisting the catalyst carriers, thecatalyst additives optimization, and the operation condition e.g. temperature, pressureand the height of the reactor bed. Among the catalysts tested, the clover-shapedalumina carriers showed the most catalytic activity under the same condition of impregnation if treated with alkaline solution.Moreover influences of different medium on the regeneration of deactivatedcatalysts were examined on the regenerants selection and temperature. Experimentsfound that the activity of the used catalyst could nearly recover to its original activityperiodically. The temperature adjustment of the reactor and regeneration manipulationof the deactivated catalyst could be easily carried out by synergistically applying airand steam in the regeneration.The final work continued in the processing and analysis of all the experimentaldata obtained and furthermore provided the basic design parameters。With theoptimical experimental data and referenced design literatures, the initial simulationand calculation of the main equipment parameters and process flow diagram wereestablished.