A series of tris-tolylbismuth(
Direct production of ethyl levulinate (EL) from glucose catalysed by a liquid acid catalyst (sulfuric acid) and a solid acid zeolite catalyst USY NKF-7 (USY) in ethanol media was investigated in this study. Effects of the initial glucose concentration (C G0), reaction temperature (T), amount of acid catalyst, and water addition on the yields of EL were compared, respectively. The results show that higher yield of EL can be obtained at lower C G0. Higher temperature and acid concentration can accelerate the reaction rate, but the formation rate of the by-products increases more quickly than that of EL. Water addition also can result in the decrease of the yield of EL. Although sulfuric acid is efficient in the production of EL, the USY is more efficient in converting glucose to 5-ethoxymethyl-2-furaldehyde. Moreover, the use of USY can limit the diethyl ether production, and it can be reused for multiple times.
本研究探讨了在乙醇介质中,利用液态酸催化剂(硫酸)和固体酸沸石催化剂USY NKF-7(USY)从葡萄糖直接制备乙基左旋酸酯(EL)的方法。分别比较了初始葡萄糖浓度(CG0)、反应温度(T)、酸催化剂用量和水添加对EL产率的影响。结果表明,较低的CG0可以获得较高的EL产率。更高的温度和酸浓度可以加速反应速率,但副产物形成速率比EL更快。水的添加也会导致EL产率的降低。虽然硫酸在生产EL方面是有效的,但USY在将葡萄糖转化为5-乙氧甲基-2-呋喃醛方面更有效。此外,使用USY可以限制二乙醚的产生,并且可以多次重复使用。