二氧化硅负载磷钨酸催化合成生物柴油

Synthesis of biodiesel catalyzed by phosphotungstic acid supported on silica

以正硅酸乙酯为硅源,采用溶胶-凝胶法制备二氧化硅负载磷钨酸催化剂,并对其进行红外光谱、XRD表征。再以菜籽油和甲醇为原料,以自制固体酸为催化剂,合成生物柴油。通过单因素实验和正交实验确定最佳反应条件。结果表明:二氧化硅负载磷钨酸催化合成生物柴油的最佳条件为磷钨酸负载量40%、醇油摩尔比6∶1、催化剂用量为菜籽油质量的10%、反应时间2.5 h、反应温度68℃,在此条件下生物柴油转化率可达96.0%。

With tetraethoxysilane as silicon resource,phosphotungstic acid supported on silica was prepared by sol-gel method,and it was characterized by infrared spectrum and XRD.The biodiesel was synthesized by esterification of methanol and rapeseed oil using the self-made solid acid as catalyst.The optimal reaction conditions were determined by single factor experiment and orthogonal experiment.The results showed that the optimal synthesis conditions of biodiesel catalyzed by phosphotungstic acid supported on silica were obtained as follows:phosphotungstic acid loading amount 40%,molar ratio of methanol to rapeseed oil 6∶1,dosage of catalyst 10%,reaction time 2.5 h and reaction temperature 68℃.Under these conditions,the conversion rate of biodiesel was 96.0%.