农作物秸秆加压液化制备乙酰丙酸乙酯及其分离初探

Preliminary Study on Pressurized Liquefaction of Three Crops Straw for Preparation of Ethyl Levulinate

分别选取小麦、玉米和水稻等3种农作物的秸秆为原料,乙醇为溶剂,98%浓硫酸为催化剂,在反应压力2.25 MPa,反应温度200℃,催化剂用量5%,反应时间60 min和固液比1∶15(质量比)的条件下,进行加压液化的初步研究,对液化产物进行分析,并分离得到液化产物中的乙酰丙酸乙酯(EL)。结果显示:同等液化条件下,所选原料中小麦秸秆的液化效果最好;FT-IR、TG-DTG和SEM分析表明液化过程中小麦秸秆组分的结构发生改变和降解,液化产物的主要组分为EL,在水相的乙酸乙酯萃取液中EL的GC含量为52.61%;在蒸馏分离的过程中,EL的纯度可达92.71%,回收率达89.93%。

Three kinds of crops （wheat, corn and rice） straw were selected as raw materials for pressurized liquefaction. Ethanol and concentrated sulfuric acid （98%） were used as solvent and catalyst, respectively. The liquefaction was carried out under the conditions of reaction temperature 200 ~C, the dosage of catalyst 5% , the reaction time 60 min and the solid-liquid ratio 1 ： 15. Products of liquefaction were analyzed, and ethyl levulinate （EL） was isolated from the liquefaction products. The results showed that under the same liquefaction conditions, wheat straw performed high liquefied performance. The structure of straw components was changed and degraded. Ethyl levulinate was the main component of liquefaction products. The purity and recovery rate of ethyl levulinate isolated by distillation were 92.71% and 89.93% , respectively.