The Develop Of HZSM-5Catalyst And Its Applications In Cyclohexene Hydration Process

Cyclohexanol is an excellent high boiling point organic chemical product, it as intermediate raw material of the production of adipic acid, nylon66a in the industry. The traditional production method of cyclohexanol is the cyclohexane oxidation. Cyclohexene hydration process is a more economic and security cyclohexanol production process, its core technology has been Japan’s Asahi Kasei Corporation to master. Therefore, this paper has engaged in the HZSM-5zeolite catalyst preparation and characterization, optimization of cyclohexene hydration reaction conditions, the stability of the prepared HZSM-5zeolite were studied.Firstly, we have used three kinds of HZSM-5zeolite catalyst synthesize methods, hydrothermal synthesis, pre-crystallization and adhesive, synthesized samples were characterized by XRD, SEM, N2adsorption and NH3-TPD. Results show that the pre-crystallization synthesis of HZSM-5has a higher diffraction peak area and peak intensity, small crystalline scales; nanostructures, the average grain size is about 500nm, coral rendering rules spherical and spherical cube grain evenly distributed; specific surface area of420m2/g, micropore distribution in the pore size of0.7nm, mesoporous mainly distributed in the3.8nm; acid quantity was significantly greater than the other two methods.Secondly, the paper examines the different Si-Al ratio of HZSM-5zeolites for the catalytic effect of cyclohexene hydration, and Si-Al ratio of HZSM-5zeolite, the NH3-TPD characterization results show that the acidity of molecular sieves with Si-Al ratio decreases, the HZSM-5zeolite with SiO2/Al2O3=25has the best catalytic effects. The optimized of cyclohexene hydration reaction conditions showed that the reaction temperature of120℃, reaction pressure of0.65MPa, the reaction time4h, the volume ratio of cyclohexene and water is2:5, the amount of catalyst was12wt%, the stirring speed is350r/min response conditions, the yield of cyclohexanol was best.Finally, this paper studied the stability of the hydration reaction of HZSM-5zeolites. The results showed that4hour is best reaction time, the yield of cyclohexanol reach maximum at8h, the HZSM-5zeolite of reuse1,3,5characterization show that the increase in the number of repeated use, the crystal structure of the sample, surface properties and acid quantity without major changes. The repeated use of HZSM-5zeolite catalyst transmittance gradually decreased, but the transmittance decreased slowly after2to5times.