为了减少生物柴油制备过程中传统催化剂对环境的污染,开发新型固体催化剂具有重要意义。该文以纤维素为原料,采用碳化-磺化法制备了碳基固体酸催化剂,并利用SEM(scanning electron microscope)、BET比表面积测试法、XRD(X-ray diffracti...为了减少生物柴油制备过程中传统催化剂对环境的污染,开发新型固体催化剂具有重要意义。该文以纤维素为原料,采用碳化-磺化法制备了碳基固体酸催化剂,并利用SEM(scanning electron microscope)、BET比表面积测试法、XRD(X-ray diffraction)和NH3-TPD(NH3-temperature programmed desorption)对其结构进行表征。研究了碳基固体酸催化剂催化棕榈酸和甲醇通过酯化反应制备生物柴油的工艺条件,考察了不同醇酸摩尔比、反应时间、反应温度及催化剂用量对转化率的影响,并对比了加压条件下碳基固体酸催化剂与浓硫酸和对甲苯磺酸的催化活性。试验结果表明,当醇酸摩尔比10:1,反应温度110℃,反应时间2 h,碳基固体酸催化剂用量为棕榈酸质量的5%时,转化率可达到98.11%。在加压条件下,碳基固体酸的催化活性高于浓硫酸和对甲苯磺酸,且催化剂在使用4次后,转化率仍在60%以上。通过GC-MS分析得出制备的生物柴油甲酯质量分数为93.8%。该研究为纤维素基碳基固体酸制备生物柴油提供了依据。展开更多
Ethyl lactate was synthesized starting from lactic acid and ethanol over solid superacid SO2-4/ZrO2-La3+ catalyst.The influence factors were investigated.The results showed that the appropriate conditions were as foll...Ethyl lactate was synthesized starting from lactic acid and ethanol over solid superacid SO2-4/ZrO2-La3+ catalyst.The influence factors were investigated.The results showed that the appropriate conditions were as follows:SO2-4/ZrO2-La3+ was made by adding ZrO2 to 1.5 mol.L-1 H2SO4 and 0.1mol.l-1La3+,immersing 24 hours,baking 2 hour at 600℃.The molar ratio of ethanol to lactic acid was 1.5∶1,reaction time was 3 hours,weight of catalyst is 2.0% of lactic acid mass.The yield of ethyl lactate reached up to 51.4%.展开更多
文摘Ethyl lactate was synthesized starting from lactic acid and ethanol over solid superacid SO2-4/ZrO2-La3+ catalyst.The influence factors were investigated.The results showed that the appropriate conditions were as follows:SO2-4/ZrO2-La3+ was made by adding ZrO2 to 1.5 mol.L-1 H2SO4 and 0.1mol.l-1La3+,immersing 24 hours,baking 2 hour at 600℃.The molar ratio of ethanol to lactic acid was 1.5∶1,reaction time was 3 hours,weight of catalyst is 2.0% of lactic acid mass.The yield of ethyl lactate reached up to 51.4%.
