The effect of dealkhylcyclization on xylene production on Me-ZSM-5/mordenite bizeolite catalyst of 1,2,4-trimethylbenzene and n-pentane

Aromatic compounds have various uses in the petrochemical industry. There are existing processes for the production of aromatics, and these processes have been studied by many researchers. Recent studies have focused on evaluating the severe reforms that have emerged from the reform process in the petrochemical industry. There are studies to assess that there is no demand for supply to these heavy reforms and to add gasoline. There are different reactions and different catalysts used for these reactions in the production processes that take place. One of them is to convert these heavy reformates into valuable aromatic compounds on zeolite catalysts by reaction with light alkanes. 1,2,4-Trimethylbenzene (TMB) constitutes 39% of the heavy reformate composition. The evaluation of this product is of particular importance. A large part of the aromatic compounds necessary for the petrochemical industry are produced in Reforming Processes. This process is a catalytic process that converts it into aromatic-rich reformate. Zeolites are widely used as catalysts for catalytic reactions of aromatics. Zeolites are preferred as catalysts in the petrochemical industry with their surface areas, strong acid centers and micropores. Within the scope of this thesis, the dealkylcyclization of Pentane with 1,2,4-TMB in a molce 1:1 ratio on mordenite, ZSM-5, ZSM-5/Mordenite bizeolites and metal-loaded bizeolite catalysts was carried out experimentally in a fixed bed continuous system. Zeolite catalysts have been prepared in pure states and in ZSM-5/Mordenite mass ratios of 1:1, 1:2 and 2:1 for this reaction, which has been performed for the first time. From the experiments performed, Nickel (Ni) and Zinc (Zn) metals were loaded with wet impregnation method to the one with the highest efficiency among zeolite catalysts that have become useolite. For the characterization of the prepared catalysts, BET, SEM, EDS and FTIR analyses were performed. The reaction parameters were determined as temperature and cavity velocity (WHSV). Experiments were carried out at 400°C, 450°C and 500°C and 1,2,3 cavity velocities respectively and the liquid products obtained were analyzed with GC-MS analyzer. In the experimental results, the highest heavy reformate (1,2,4-TMB) and pentane conversions were observed at 500°C on Ni loaded ZSM-5/Mordenite bizolite catalyst and 97.8% and 99.7%, respectively, at WHSV1. The highest value of xylene yield is 11% in pure form of Mordenite zeolite catalyst and reaction conditions are 400°C and WHSV2. The m/p-Xylene yield, which is the highest among the modified ZSM-5/Mordenite bizolite forms, is 10.4% on Ni-ZSM-5/Mordenite bizolite catalyst, and the reaction conditions are 500°C and WHSV1. The selectivity of m/p-Xylene reached the highest value in ZSM-5/Mordenite bizolite catalyst prepared at 450°C and WHVS2 with 10.87% to 1:1 ratio. The maximum xylene selectivity value reached in metal-loaded catalysts was 6.6% with Ni-ZSM-5/Mordenite bizolite. Mordenite catalyst with the highest amount of coke deposited on the prepared catalysts is 0.6% at 500°C. The zeolite catalyst with the least coke accumulation was at 400°C WHSV3, the 2:1 ratio of the ZSM-5/Mordenite bizolites. With the increase in temperature, coke accumulation also increases. The coke resistance of ZSM-5 is higher than Mordenite.