Research On The Reaction Of Isomerization From N-Butane To Iso-Butane On Pt/Zeolite Catalysts

Iso-butane is an important chemical raw material, used to synthesize MTBE which is an important gasoline addition, it can enhance anti-detonating quality of gasoline. I can get n-butane and iso-butane through isolation the gas oil,but with the demand of iso-butane increasing, separated iso-butane far failed to meet the demand, and because the smaller value of n-butane, so there is an urgent need to develop the technology about making iso-butane through the reaction from n-butane to iso-butane, to expand the source of iso-butane.To resolve the problem of how to accurately analyze product component, this article establish a set of analytical methods, specifically including gas detection and data analysis. Using the configuration of the FID detector GC-8600 gas chromatograph, and column in gas chromatograph is HP-Al2O3, which can clearly separate a total of eight components from C1 toC5. Using much higher accuracy in data processing calibration area normalization, In order to further reducing the experimental error.In this paper, there is a series of experiments on mordenite molecular sieve to to characterize the two batches of the same ratio of silicate to aluminium, one of the most important experiment is the Py-IR. Under the same conditions including the catalyst preparation process and catalyst evaluation experiments, two groups of the catalyst was evaluated. The experimental results show that the 2014 batch mordenite molecular sieve who has more regular lattice structure, more surface area, more acid content has better catalytic performance. This article also continue to optimize the 2014 batch mordenite molecular sieve, the next is the experiment of acid dealumination, which is completed under the same conditions including the catalyst preparation process and catalyst evaluation experiments as before. The results show that the process of acid dealumination lead to the increase of ratio of silicate to aluminium of the mordenite, the higher ratio of silicate to aluminium bring the bad catalytic performance, such as the reduction of selectivity of iso-butane and the increace of selectivity of by-products. The next step is to optimize the experimental conditions of the mordenite catalyst, and the results show that the suitable reaction conditions as follows:reaction temperature is 340～370℃, reaction pressure is 1.5～3.0MP, n-butane liquid WHSV 1～3h-1.One step of modenite catalyst preparation is extruding which means put mordenite molecular sieve and pseudo-boehmite together before extruding, so in order to study this variable, a special chapter experiments was set. There areSix experiments on the baseis of the quality ratio of mordenite to pseudo-boehmite, such as 6:1、4:1、2:1、1:1、1:2、1:4. The six experiments is also under the conditions including the catalyst preparation process and catalyst evaluation experiments as before. From the experiments we can find that when the quality ratio is 2:1, the catalyst has the best performance. Under this bast condition, the conversion of n-butane reached 29.01%, selectivity of iso-butane reached 66.12%, iso-butane and propane overall selectivity reached 83.67%, and the overall selectivity of methane and ethane reduced 9.01%, three kinds of pentane overall selectivity reduced 7.32%.