碳基固体酸催化剂的制备及其应用研究

【作者】 李昊；

【导师】 苏有勇；

【作者基本信息】 昆明理工大学 ， 农业生物环境与能源工程， 2011， 硕士

【摘要】 生物柴油是一种新型绿色能源,生产原料主要是来自于动植物油脂和回收的废油脂。因其具有含硫量低、对环境污染较小、可再生等优势而备受关注。利用餐饮废油为原料是我国生产生物柴油的优势,我国每年产生大量餐饮废油,如果以其作为原料生产生物柴油,一定能够产生很好的经济效益。目前,在我国生产生物柴油主要以酯交换反应法为主。餐饮废油的酸值较高,酯交换法制备生物柴油需要原料油的酸值必须小于1,因此需降酸处理。降酸过程在酯化反应中进行,一般采用强酸(硫酸)作为催化剂,但对设备有腐蚀,并会产生大量的废水,而且催化剂不能回收。碳基固体酸催化剂是一种新型固体酸催化剂,使用此种催化剂可以避免酸腐蚀及产生大量废水等不利环境的因素,还能够显著的降低生产成本。本文首先对新型碳基固体酸催化剂的制备进行了探索式的研究,以生物质块状竹料(杆径为0.3～0.5cm)合成了碳基固体酸催化剂。采用扫描电镜(SEM)、红外光谱(FT-IR)对催化剂进行了表征。利用油酸模拟高酸值生物柴油原料进行气相酯化降酸应用研究,并考察了碳化温度、磺化时间、磺化温度对催化活性的影响。酯化反应温度92℃,反应时间3h,催化剂用量为油酸质量的6%,甲醇蒸气为75℃。实验结果表明：以碳化温度在210℃,磺化时间7h,磺化温度70℃时所制备的碳基固体酸催化剂参与气相酯化反应,反应结束后测得油酸的转化率为86.93%。催化剂在重复使用4次,转化率仍能达到60%以上。试验还对催化剂再生利用进行了试验研究,实验结果催化剂的活性基本得到恢复。在此基础上以新方法制备出磁性碳基固体酸催化剂。此种催化剂带有磁性,在制备生物柴油的过程中如在反应器皿以外添加磁场,可以影响催化剂在反应器内的分布及反应后的回收。对制备的磁性催化材料采用扫描电镜(SEM)、红外光谱(FT-IR)、X-射线衍射(XRD)进行了表征,并考察了催化剂制备条件中磺化温度及时间、磺化酸量对反应转化率的影响。实验选用温度为500℃,活性炭与三氧化二铁质量比1：3混合,高温加热8h,得到的磁性材料经磺化温度70℃,磺化时间6h,磺化酸量7ml制成的磁性碳基固体酸催化剂参与生物柴油气相酯化降酸试验；酯化反应温度95℃,反应时间为3h,催化剂用量定为油酸质量的6%,甲醇蒸气75℃。反应后油酸转化率为85.82%。催化剂回收率为96.37%,且回收方法简单。催化剂重复使用4次后,反应中油酸的转化率仍能达到55%以上。磁性碳基固体酸催化剂具有较好稳定性及催化活性。在生物柴油生产中,应用碳基固体酸催化剂催化高酸值生物柴油原料降酸过程,具有很好的应用前景和经济价值。更多还原

【Abstract】 Biodiesel is a kind of green renewable energy, because of has the sulphur content lowly, renewable, merits and so on environmental protection to receive the attention. The Biodiesel production are mainly the zoology and botany fat and the recycling waste fat.Our country makes biodiesel with a superiority raw material of the dining- used oil, its not only fruitful in resources, moreover the price is cheap. At present, in industrial production mainly by transesterification preparation for biodiesel. But, the dining used oil’s acid value is very high, the transesterification preparation for biodiesel that request raw oil acid value to be smaller than 1, must therefore fall the oil acid value treatment. Falls the sour process, in the esterification carries on, generally uses the strong acid (sulfuric acid) to take the catalyst, but has the corrosion to the equipment, and will produce the massive waste water, and the catalyst cannot be recycled.The carbon base solid acid catalyst is one new kind of the solid acid catalyst, may avoid the acid corrosion and the waste of water and disadvantageous environmental factor, can reduce the production cost. This article first has conducted the exploration-like experimental study to the new carbon base solid acid catalyst’s preparation, take lived the material bamboo (pole diameter is 0.3～0.5cm) synthesized the carbon base solid acid catalyst as raw material. The catalyst samples were characterized by scanning electron microscopey (SEM), Fourier transform infrared (FT-IR) spectroscopy.The experiment simulates the high acid value of biodiesel raw material using the oleic acid to carry on the gaseous esterification to fall the acid experiment, and inspected the carbonization temperature, the sulfonation time, the sulfonation temperature to the catalytic activity influence. Esterification reaction temperature 92℃, reaction time 3h, catalyst amount used for oleic acid quality 6%, vaporization temperature for 75℃. The experimental result indicated:Carbonization temperature 210℃, sulfonation time 7h, sulfonation temperature 70℃prepares the carbon base solid acid catalyst uses in the esterification responding that the conversion rate is 86.93%. The catalyst after repeatedly uses use 4 times, the oleic acid conversion rate still could achieve above 60%. Meanwhile has conducted the exploration type experimental study to the catalyst regeneration use, the experiment result that activities of the catalyst can be recovery.On the foundation in new way preparation the magnetic carbon base solid acid catalyst. This catalyst has magnetism, in the process preparation of biodiesel that toward outside increase the magnetic field, it can be control distribution of the catalyst in the reactor and the catalyst recycling. The preparation materialof magnetic catalyst with the scanning electron microscope (SEM), Fourier transform infrared (FT-IR) spectroscopy, and the X-ray diffractometer (XRD) to carry on the characterized,, simultaneously inspected the sulfonation temperature, the sulfonation time, the sulphur acidify quantity to the esterification’s conversion rate influence. The experiment selects the temperature for 500℃, the activated carbon and the ferric oxide quantity compare 1:3, heat up 8h, obtains the magnetic material after the sulfonation temperature 70℃, sulfonation time 6h, the sulfuric acid 7ml. Uesd the magnetic carbon base solid acid catalyst makes to fall the acid experiment by participation the gaseous esterification, the esterification’s conversion rate 85.82%. The catalyst of recycle rate is 96.37%, and the recycling method is very simple. The esterification reaction temperature at 95℃,reaction time3h, the catalyst amount used for the oleic acid quality 6%, the vaporization temperature for 75℃. The catalyst after repeatedly uses use 4 times, that the oleic acid conversion rate still could achieve above 55%.The catalyst stability and the activity are good. In the production of biodiesel, high acid value of raw material was explored to reduce the acid value that using the carbon base solid acid catalyst, has the very good application prospect and the economic value.更多还原