Study On The Process Of By-product 2-Picoline To 2-Vinylpyridine

2-Picoline is the by-product in the preparation of diphenylamine with aniline. For using it well, 2-vinylpyridine was chosen as the product which was of great value with 2-picoline as raw material in view of the market benefit and environmental protection.2-Vinylpyridine is a kind of important organic synthesis intermediate. It is widely used in rubber industry, function macromolecule material, electronic material, medicine and pesticide industry. Among these, very large quantities of rubber material VPL are produced with 2-vinylpyridine.It has very good market future.The preparation of 2-vinylpyridine from 2-picoline mainly have two process routes——two-step process in liquid phase and one-step process in gas phase. The one-step process in gas phase was chosen to synthesize 2-vinylpyridine. The reaction was carried out in the fixed bed reactor, with ZSM-5 zeolite catalyst modified by KOH, to prepare 2-vinylpyridine from 2-picoline and formaldehyde. The effects of roasting temperature of catalyst, concentration of potassium ion, species and content of adhesion agents during shaping, the process parameters on the reaction had been studied. The catalyst was preferably calcined at 550℃, and the weight of potassium was 3% in HZSM-5 catalyst. The silica sol was used to shape the catalyst and the preferable use level of silica sol was half the mass of K-HZSM-5 catalyst. The conversion of 2-picoline was obtained 80.37%, and the selectivity of 2-vinylpyridine was 96.85% at 360～370℃,0.5h-1 weight hourly space velocity and 1:3 molar ratio of 2-picoline to formaldehydeThe deactivation of the above zeolite catalyst was studied in this paper. The deactivation of the catalyst was caused by carbon deposit and coking in the catalyst surface. After the reaction carried out for 12 hours, the conversion of 2-picoline from the initial 80% declined to 50%. But the catalyst could be regenerated by burning carbon deposit in the surface. After the regeneration for 10 times, the initial catalytic activity of catalyst almost had no change. The effects of temperature and composition...