知识与财富的链接
以去除半纤维素的玉米芯为原料,通过高温炭化、浓硫酸磺化制备了生物炭基固体酸催化剂,用于油酸酯化制备生物柴油,并对催化剂进行了表征。考察了炭化温度、炭化时间、磺化温度、磺化时间等制备条件对催化剂的影响,探究了反应温度、反应时间、醇油摩尔比、催化剂质量分数对油酸酯化反应的影响。结果表明,适宜的催化剂制备条件为300 ℃炭化3 h、25 ℃磺化4 h,在此条件下制备的生物炭基固体酸酸量为1.67 mmol/L;适宜的反应条件为反应温度65 ℃,反应时间5 h,甲醇与油酸的摩尔比12：1,催化剂质量分数4%,在此条件下,油酸转化率为98%。催化剂在使用4次后,催化剂活性下降至63%,经过重新磺化,油酸转化率可恢复至94%。
Biochar-based solid acid catalyst was prepared from corncob without hemicellulose by high temperature carbonization and concentrated sulfuric acid sulfonation. The catalyst was used for esterification of oleic acid to produce biodiesel. The effects of carbonization temperature, carbonization time, sulfonation temperature, and sulfonation time on the preparation of the catalyst were investigated.The effects of reaction temperature, reaction time, alcohol-oil molar ratio and catalyst mass fraction on oleic acid esterification reaction were explored.The results showed that the optimum preparation conditions were carbonization at 300 ℃ for 3 h and sulfonation at 25 ℃ for 4 h. Under these conditions, the acid content of biochar solid acid was 1.67 mmol/L. The optimum reaction conditions were as follows: reaction temperature 65 ℃, reaction time 5 h, molar ratio of methanol to oleic acid 12:1, catalyst mass fraction 4%. Under these conditions, the conversion rate of oleic acid was 98%.The activity of the catalyst was reduced to 63% after 4 times of use, and the conversion rate of oleic acid was restored to 94% after re-sulfonation.
