Study On Catalysts And Reactivity For Synthesis Of 2-Methyltetrahydrofuran From 2-Methylfuran Hydrogenation

2-methyltetrahydrofuran is widely used in biogasoline fuels,pharmaceutical intermediates and high-end environmentally friendly solvents.At present,my country’s demand for 2-methylfuran is in short supply,mainly from imports,and the price is high.Up to now,there are three main methods for synthesizing2-methyltetrahydrofuran at home and abroad,followed by the glycol method,the lactone method and the furfural method.The most common method for the synthesis of 2-methylfuran from furfural is a two-step method.The second step in the two-step method is to hydrogenate 2-methylfuran to produce 2-methyltetrahydrofuran.This reaction needs to be carried out under high pressure conditions,and precious metals are used as catalysts,which is not conducive to reducing industrial production costs.Therefore,the core purpose of improving the preparation process of2-methyltetrahydrofuran is to develop cheap and efficient catalysts and optimize reaction conditions.This laid a solid theoretical foundation for future generations to study the scientific road of 2-methylfuran hydrogenation to 2-methyltetrahydrofuran,and also broadened the way for industrial mass production.In this experiment,nickel nitrate was used as a nickel source,and alkaline silica sol was used as a silicon source.The Ni/SiO₂ catalyst was prepared by ammonia distillation and used in the gas phase hydrogenation of 2-methylfuran to produce2-methyltetrahydrofuran.The experiment investigated the effects of ammonia distillation temperature,reaction temperature,reaction pressure,H₂/furan ratio and liquid hourly space velocity on the catalyst structure and catalytic performance.On this basis,additives Ca,Zn,and Al were added to the Ni/SiO₂ catalyst.X%Ca-Ni/SiO₂（X represents 1,2,3 or 5）,X%Zn-Ni/SiO₂ and X%Al-Ni/SiO₂catalysts were prepared respectively.A fixed-bed reactor was used to investigate the reaction performance of the catalyst in the gas phase hydrogenation of 2-methylfuran（2-MF）to 2-methyltetrahydrofuran（2-MTHF）by the temperature and reaction conditions of the catalyst for ammonia distillation.The results show that the Ni/SiO₂catalyst prepared by the ammonia distillation method all presents a layered nickel silicate structure after calcination,and maintains this structure after reduction.The active component Ni crystallite size is small and the metal support interaction is strong,so it has Higher activity.The 5%Ca-Ni/SiO₂ catalyst prepared under the conditions of ammonia distillation at 80°C has the best performance.Under optimized reaction conditions,the conversion rate of 2-MF is 100%,the selectivity of 2-MTHF is 96.92%,and the catalytic performance is stable within 15 hours of reaction;Carbon on the surface of the catalyst causes deposits to cover the surface of the catalyst,which in turn deactivates the catalyst.