改性分子筛催化果糖制备液体生物燃料5-乙氧基甲基糠醛的研究

Preparation of liquid biofuel 5-ethoxymethylfurfural from fructose catalyzed by modified molecular sieve

【目的】探究改性超稳Y型分子筛(ultrastable Y-type zeolites,USY)催化果糖制备高能量密度液体生物燃料5-乙氧基甲基糠醛(5-ethoxymethylfurfural,EMF)的最优工艺条件,以及改性催化剂结构和酸性位点变化对果糖转化EMF的影响。【方法】选用磷酸二氢铵对USY进行浸渍改性,催化果糖一锅法制备EMF,并利用响应面试验方法进行优化,得到了果糖制备EMF的最优工艺条件,并通过GC-MS分析,对改性催化剂的特性进行表征。【结果】改性催化剂催化果糖制取EMF的最优工艺条件为反应温度127℃、反应时间32 min、催化剂用量质量分数1.35%,此时EMF产率达74.9%,比未改性催化剂提高了13.6%;通过对产物进行GC-MS分析,得到改性USY催化果糖醇解得到的主要产物为EMF。【结论】磷酸二氢铵改性USY催化果糖制取EMF的副产物较少,产率较高。

【Objective】The study was conducted to investigate the optimal process conditions for the preparation of high-energy density liquid biofuel 5-ethoxymethylfurfural(EMF)from fructose catalyzed by modified ultrastable Y-type zeolites(USY),and the effect of modified catalyst structure and acidic site changes on the conversion of fructose to EMF was investigated.【Method】In this study,USY was modified by impregnation with ammonium dihydrogen phosphate to catalyze the preparation of EMF from fructose by the one-pot method,and the optimal process conditions for the preparation of EMF from fructose.The effects of structural and acidic site changes on the conversion of fructose to EMF were investigated accordingly were optimized by response surface testing,and the modified catalysts were characterized by GC-MS analysis.【Result】The optimal process conditions for the preparation of EMF from fructose catalyzed by the modified catalyst were 127℃reaction temperature,32 min reaction time and 1.35%mass fraction of catalyst dosage,at which the EMF yield reached 74.9%,which was 13.6%higher than that of the unmodified catalyst;the main product obtained from the alcoholysis of fructose catalyzed by modified USY was EMF by GC-MS analysis of the product.【Conclusion】The ammonium dihydrogen phosphate modified USY can successfully catalyze the production of EMF from fructose with fewer by-products and higher yield.