采用固体磷钨酸铯盐催化光皮树油制备生物柴油

Preparation of biodiesel from Cornus wilsonian oil catalyzed by solid cesium phosphotungstates

合成3种固体磷钨酸铯盐CsxH3-xPW12O40(x=2.0,2.5,3.0),并采用FT-IR,XRD和BET手段分别对其进行表征。以CsxH3-xPW12O40(x=2.0,2.5,3.0)为固体催化剂,催化光皮树油与甲醇制备生物柴油,考察这3种不同的催化剂在相同的反应温度、反应时间、醇油摩尔比、催化剂质量分数等因素下对生物柴油转化率的影响。研究结果表明:与催化剂Cs2HPWl 2O40和Cs3PWl 2O40相比,Cs2.5H0.5PWl 2O40具有较强的催化活性,其在反应温度为65℃、反应时间为20 h、醇油摩尔比为9-1、催化剂质量分数为2.8%时光皮树油转化成生物柴油的转化率可达91.0%;高比表面和超强酸性的固体磷钨酸铯盐不受光皮树油中游离脂肪酸和水分的影响,易分离,可重复使用,是制备生物柴油的绿色环保型固体催化剂。

Abstract： Solid cesium phosphotungstates CsxH3-xPWl2O40（X=2.0, 2.5, 3.0） were synthesized and characterized by FT-IR, XRD and BET techniques. CSxH3-xPWl2O40（x=2.0, 2.5, 3.0） were used as a solid catalyst for the production of biodiesel from Comus wilsoniana oil with methanol respectively. The three catalysts were compared under the same conditions of reaction temperature, reaction time, molar ratio of methanol to oil and catalyst dosage on the conversion rate of Comus wilsoniana oil. The results show that CS2.5H0.5PW12O40 has higher catalytic activity than Cs2HPW12O40 and Cs3PW12O40. The conversion of Comus wilsoniana oil can be up to 91% under the reaction condition of molar ratio of methanol to oil 9：1, catalyst dosage 2.8%, temperature 65 ℃, reaction time 20 h by the catalyst of Cs2.5H0.5PW12O40. Solid cesium phosphotungstates of high surface area and the most acid strength are not affected by free fatty acid content and moisture in Comus wilsoniana oil. Furthermore, they can be separated from the biodiesel easily and can be used repeatedly. Therefore, solid cesium phosphotungstates are green environmental protection solid catalysts for the production of biodiesel.