摘要
以废弃猪油为原料采用两步催化工艺制备生物柴油.首先,在40kHz的超声波辐射下,以浓硫酸为催化剂进行猪油和甲醇的预酯化反应;然后,采用等体积浸渍法制备了固体CaO/NaA催化剂;最后,在40 kHz的超声场中,用最佳条件下制备的固体碱催化剂催化预酯化后的猪油与甲醇进行酯交换反应制备生物柴油.结果表明:对于初始酸值为13.82 mg KOH/g的猪油,最佳预酯化条件为超声功率150 W、醇油摩尔比8∶1、反应温度50℃、浓硫酸用量2.5%;在最佳预酯化条件下反应30 min,即可把猪油的酸值降到1.91 mgKOH/g;通过正交试验得到的固体CaO/NaA催化剂最佳制备条件为CaO负载量15%、焙烧温度700℃、焙烧时间6h;在超声功率150W、醇油摩尔比9∶1、55℃、固体碱催化剂用量4%的最佳生物柴油制备条件下反应120 min,甲酯转化率达到了约95.8%;固体碱催化剂重复使用3次后仍保持较高的活性.
In this investigation, a two-step catalysis process was developed to prepare the biodiesel from the waste lard. First, under the irradiation of 40 kHz ultrasonic, the pre-esterification of the lard with methanol is carried out by using concentrated sulfuric acid as the catalyst. Then, the solid base catalyst CaO/NaA was prepared by means of the isovolumetric impregnation. Finally, the solid base catalyst prepared in optimal conditions was employed to catalyze the transesterification of the pre-esterified lard with methanol in a 40 kHz ultrasonic field, thus obtaining the biodiesel. The results show that, for the pre-esterification of lard with an initial acid value of 13.82mg KOH/g, optimal conditions are a ultrasonic power of 150W, a methanol-to-oil molar ratio of 8： 1, a reaction temperature of 50 ℃ and a concentrated sulfuric acid dosage of 2. 5 % , and under such conditions, the acid value of lard can be reduced to 1.91 mg KOH/g in 30 min, that the optimal preparation conditions of the solid base catalyst CaO/NaA, which are obtained by the orthogonal experiments, are a CaO loading amount of 15%, a masting temperature of 700 ℃ and a roasting time of 6h; and that the conversion of methyl ester reaches about 95.8% in 120min in optimal preparation conditions of the biodiesel, namely, a ultrasonic power of 150 W, a methanol-to-oil molar ratio of 9： 1, a temperature of 55 ℃ and a solid base catalyst dosage of 4%, and the solid base catalyst is still of high activity after being used three times.
出处
《华南理工大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第9期8-13,共6页
Journal of South China University of Technology(Natural Science Edition)
基金
广东省教育部产学研结合项目(2011B090400116)
广州市科技攻关项目(2012J4300758)
