Study On Catalyst Preparation Of Methanol To Gasoline And Reaction Process

China has rich reserves of coal resources,and the methanol to gasoline technology(MTG),as a branch of coal indirect liquefaction,can effectively alleviate the current energy shortage in China.An important problem faced by the methanol to gasoline technology is the development of catalysts with good catalytic activity,high gasoline selectivity and long life.HZSM-5 zeolite catalysts are often used to catalyze methanol to make gasoline.However,the selectivity of gasoline and service life of directly synthesized HZSM-5 catalyst is often difficult to achieve the desired results.Therefore,the modification of HZSM-5 zeolite catalyst by different methods is an important method for improving the selectivity of gasoline and prolonging the service life of HZSM-5 zeolite.In order to improve the performance of HZSM-5 catalyst,the following research work was mainly done in this paper:First,HZSM-5 was treated with steam,and the effects of steam treated HZSM-5 catalysts with different temperature and mass space space on the reaction performance of MTG were investigated.The results showed that HZSM-5 after steam treatment increased the initial yield of C5+,prolonged the life of the catalyst,and obtained the most at the HZSM-5 catalyst treated with a steam mass space of 4 h-1 and a temperature of 500 ?.As a result,the initial C5+ yield increased by 4.77%and the lifetime increased by 40 h.Secondly,on the basis of optimizing the steam treatment,the steam treated HZSM-5 catalyst is treated with nitric acid.The comparison of the effects of HZSM-5 with different mass fractions of nitric acid on the reaction performance of MTG shows that the 15%nitric acid-treated HZSM-5 has better catalytic effect and compared with the untreated HZSM-5 catalyst,the initial C5+ yield is improved by 0.58%,lifetime increased by 45 h.Then,based on the nitric acid treatment,the catalyst was modified with non-metallic P.The performance of HZSM-5 catalysts with different P loadings was investigated.The results showed that when the P loading was 1%,the catalyst life increased by 155 h and the catalyst life was significantly improved.Finally,based on the non-metallic P modification treatment,the metal La ion exchange was performed on the HZSM-5 catalyst.The results showed that compared with the untreated HZSM-5,the initial C5+yield of the catalyst treated with a mass fraction of 0.2%La solution increase by 3.64%,lifetime increased by 100 h.The modified HZSM-5 was characterized by XRD,BET and NH3-TPD.The characterization results show that the modification treatment has a significant effect on the pore structure and acid properties of the catalyst.After non-metal P treatment,the crystallinity of the catalyst decreased,the number of strong acid sites and weak acid sites decreased,and the specific surface area and pore size increased.