K_2O/CaO-SBA-15催化大豆油制备生物柴油研究

通过浸渍法制备固体碱催化剂:K2O-SBA-15、CaO-SBA-15和K2O/CaO-SBA-15,用于催化大豆油和无水甲醇发生酯交换反应制备生物柴油,并进行X射线衍射(XRD),氮气吸附脱附表征。结果表明,负载固体碱后,没有改变介孔分子筛SBA-15的规则孔道结构,并且碱金属氧化物均匀负载在SBA-15的孔壁上。按三组分四因素的正交试验设计方案进行实验,表明各因素影响制备生物柴油的程度依次为:反应时间反应温度醇油摩尔比催化剂用量。反应的最佳条件为:以3%K2O/3%CaO-SBA-15为催化剂,反应温度60℃,反应时间3h,醇油摩尔比为16:1,催化剂用量为油重的3%,可得生物柴油产率为87.12%。     

固体碱K_2CO_3/γ-Al_2O_3催化棉籽油酯交换法制备生物柴油

研究了适合新疆地区棉籽油制备生物柴油的工艺条件和检测产物的方法,采用单因素和正交实验优化了棉籽油制备生物柴油的反应条件。结果表明,确定优化反应条件为:醇油摩尔比7:1,碳酸钾的用量为1.0%,反应温度60℃,反应时间2h。在此条件下,产率可达96.7%。该研究结果对棉籽油转化生物柴油的应用具有实际意义。     

正交试验探讨固体碱催化制备生物柴油

采用等体积浸渍法制备了K2CO3/NaX固体碱催化剂,用于催化酯交换反应制备甲酯生物柴油。通过正交试验方法确定了最佳反应条件为:反应时间3 h、反应温度60℃、催化剂用量4%和醇油摩尔比14。在此反应条件下生物柴油的转化率可达87.5%。     

正交试验探讨固体碱催化制备生物柴油

采用等体积浸渍法制备了K2CO3/NaX固体碱催化剂,用于催化酯交换反应制备甲酯生物柴油。通过正交试验方法确定了最佳反应条件为:反应时间3 h、反应温度60℃、催化剂用量4%和醇油摩尔比14。在此反应条件下生物柴油的转化率可达87.5%。     

固体碱催化剂生产生物柴油的研究进展

固体碱性催化剂以其反应条件温和、反应速度快、较酸催化剂腐蚀性小等优点而成为生产生物柴油的酯交换反应中广泛使用的一类催化剂,主要分为负载型固体碱和非负载型固体碱2大类型。综述了几种主要的固体碱催化剂在生物柴油中的应用状况,对其存在的问题进行了总结概括。同时在原子和分子水平上对固体碱催化剂的设计方法进行了简单的介绍。     

盐地碱蓬油制备生物柴油工艺条件研究

以盐地碱蓬油为原料制备生物柴油.通过正交实验研究了反应温度、催化剂用量、醇油摩尔比、反应时间、搅拌强度等因素对生物柴油产率的影响.结果表明,在实验范围内各影响因素对生物柴油产率作用的大小依次为:搅拌强度>反应时间>催化剂用量>醇油摩尔比>反应温度.盐地碱蓬油制备生物柴油的最佳工艺参数为:搅拌强度为1 800 r/min,反应时间60min,催化剂KOH用量为盐地碱蓬油质量的1%,醇油摩尔比6/1,反应温度65℃.在该工艺条件下,生物柴油产率达到97.03%.     

用于制备生物柴油的固体催化剂研究进展

简单介绍了生物柴油及其制备方法,重点综述了近年来国内外利用固体酸催化剂、固体碱催化剂制备生物柴油的研究进展和应用现状,并对生物柴油用固体催化剂的研究前景进行了展望。     

固体碱K_2CO_3/Mg-Al-O催化酯交换制备生物柴油

以镁铝水滑石为前驱体,经焙烧后得到的镁铝复合氧化物为载体,制备了负载型K2CO3/Mg-Al-O固体碱催化剂,并用于大豆油酯交换合成生物柴油反应中。研究了活性组分K2CO3负载量对催化剂结构和性能的影响。结果表明,在K2CO3负载量为30%时,形成的钾铝氧化物种是催化剂强碱中心和活性提高的主要原因。考察了反应条件对催化剂性能的影响,在反应温度60℃、时间6 h、醇油摩尔比12∶1和催化剂用量2.0%的条件下,生物柴油收率最高为88.5%,催化剂具有较好的稳定性。     

生物柴油合成催化剂的研究进展

生物柴油是典型的"绿色能源",是优质的石油柴油代用品。综述了酯交换方法生产生物柴油过程中催化剂的研究进展,并重点介绍了固体碱催化剂的研究状况。     

固体酸WO3／ZrO2制备生物柴油的研究

采用共沉淀法制备了固体强酸WO_3/ZrO_2,研究了WO_3负载量和焙烧温度对催化剂晶相和比表面积的影响,并且研究了WO_3/ZrO_2催化剂对葵花籽油酯交换反应制备生物柴油(BDF)的催化性能,结果表明,WO_3/ZrO_2催化剂的催化性能与WO_3负载量及晶相结构密切相关,在负载量为0.1 g WO_3/ZrO_2时,经700～800℃高温焙烧,WO_3在ZrO_2表面上达到单层分散,且大部分ZrO_2以四方晶相存在,而四方相的存在对于形成WO_3/ZrO_2的强酸性是很重要的。所制备的催化剂具有较好的催化活性,在反应温度150℃、醇油物质的量比12:1及催化剂用量为葵花籽油质量分数的3%的条件下,反应8 h后葵花籽油的转化率可以达到60%以上。     

Calcined sodium silicate as solid base catalyst for biodiesel production

This paper examined the use of calcined sodium silicate as a novel solid base catalyst in the transesterification of soybean oil with methanol. The calcined sodium silicate was characterized by DTA-TG, Hammett indicator method, XRD, SEM, BET, IR and FT-IR. It catalyzed the transesterification of soybean oil to biodiesel with a yield of almost 100% under the following conditions: sodium silicate of 3.0 wt.%, a molar ratio of methanol/oil of 7.5:1, reaction time of 60 min, reaction temperature of 60 °C, and stirring rate of 250 rpm. The oil containing 4.0 wt.% water or 2.5 wt.% FFA could also be transesterified by using this catalyst. The catalyst can be reused for at least 5 cycles without loss of activity.     

Calcium methoxide as a solid base catalyst for the transesterification of soybean oil to biodiesel with methanol

In this study, physical and chemical characterizations of calcium methoxide were investigated to assess its performance as an excellent solid base catalyst using some instrumental methods, such as BET surface area measurement, scanning electron micrographs and particle size distribution. Then, it was used to catalyze transesterification of soybean oil to biodiesel with methanol. The effects of various factors such as mass ratio of catalyst to oil, reaction temperature and volume ratio of methanol to oil were studied to optimize the reaction conditions. The results showed that calcium methoxide has strong basicity and high catalytic activity as a heterogeneous solid base catalyst and it was obtained a 98% biodiesel yield within 2 h in this reaction. Besides, the recycling experiment results showed it had a long catalyst lifetime and could maintain activity even after being reused for 20 cycles.     

ZS／HY-SBA-15负载型固体酸催化合成生物柴油

以四水硫酸锆改性HY-SBA-15（ZS／HVSBA-15）为催化剂,催化大豆油和甲醇制备生物柴油,考察最佳制备条件。实验结果表明,四水硫酸锆负载量为30％,n（甲醇）：n（大豆油）-12：1,m（催化剂）：m（大豆油）=3％,m（溶剂）：m（大豆油）：30％,120℃下反应6h,生物柴油的收率可达96．78％。对合成出的生物柴油性能指标进行检测,结果表明其主要性能指标与我国0^#柴油相接近。     

Transesterification of edible and non-edible oils over basic solid Mg/Zr catalysts

A series of Mg–Zr catalysts with varying Mg to Zr ratios was prepared by co-precipitation method. These catalysts were characterized by BET surface area, X-ray diffraction, X-ray photo electron spectroscopy and temperature programmed desorption of CO₂. The catalytic activity of these catalysts was evaluated for the room temperature transesterification of both edible and non-edible oils to their corresponding fatty acid methyl esters. The catalyst with Mg/Zr (2:1 wt./wt.%) exhibited exceptional activity towards transesterification reaction within short reaction time. The effects of different reaction parameters such as catalyst to oil mass ratio, reaction temperature, reaction time and methanol to oil molar ratio were studied to optimize the reaction conditions. The reasons for the observed activity of these catalysts are discussed in terms of their basicity and other physico-chemical properties.     

Transesterification of soybean oil to biodiesel using CaO as a solid base catalyst

In this study, transesterification of soybean oil to biodiesel using CaO as a solid base catalyst was studied. The reaction mechanism was proposed and the separate effects of the molar ratio of methanol to oil, reaction temperature, mass ratio of catalyst to oil and water content were investigated. The experimental results showed that a 12:1 molar ratio of methanol to oil, addition of 8% CaO catalyst, 65 °C reaction temperature and 2.03% water content in methanol gave the best results, and the biodiesel yield exceeded 95% at 3 h. The catalyst lifetime was longer than that of calcined K₂CO₃/γ-Al₂O₃ and KF/γ-Al₂O₃ catalysts. CaO maintained sustained activity even after being repeatedly used for 20 cycles and the biodiesel yield at 1.5 h was not affected much in the repeated experiments.     

Tri-potassium phosphate as a solid catalyst for biodiesel production from waste cooking oil

Transesterification of waste cooking oil with methanol, using tri-potassium phosphate as a solid catalyst, was investigated. Tri-potassium phosphate shows high catalytic properties for the transesterification reaction, compared to CaO and tri-sodium phosphate. Transesterification of waste cooking oil required approximately two times more solid catalyst than transesterification of sunflower oil. The fatty acid methyl ester (FAME) yield reached 97.3% when the transesterification was performed with a catalyst concentration of 4 wt.% at 60 °C for 120 min. After regeneration of the used catalyst with aqueous KOH solution, the FAME yield recovered to 88%. Addition of a co-solvent changed the reaction state from three-phase to two-phase, but reduced the FAME yield, contrary to the results with homogeneous catalysts. The catalyst particles were easily agglomerated by the glycerol drops derived from the homogeneous liquid in the presence of co-solvents, reducing the catalytic activity.     

Calcium oxide as a solid base catalyst for transesterification of soybean oil and its application to biodiesel production

In order to study solid base catalyst for biodiesel production with environmental benignity, transesterification of edible soybean oil with refluxing methanol was carried out in the presence of calcium oxide (CaO), -hydroxide (Ca(OH)₂), or -carbonate (CaCO₃). At 1 h of reaction time, yield of FAME was 93% for CaO, 12% for Ca(OH)₂, and 0% for CaCO₃. Under the same reacting condition, sodium hydroxide with the homogeneous catalysis brought about the complete conversion into FAME. Also, CaO was used for the further tests transesterifying waste cooking oil (WCO) with acid value of 5.1 mg-KOH/g. The yield of FAME was above 99% at 2 h of reaction time, but a portion of catalyst changed into calcium soap by reacting with free fatty acids included in WCO at initial stage of the transesterification. Owing to the neutralizing reaction of the catalyst, concentration of calcium in FAME increased from 187 ppm to 3065 ppm. By processing WCO at reflux of methanol in the presence of cation-exchange resin, only the free fatty acids could be converted into FAME. The transesterification of the processed WCO with acid value of 0.3 mg-KOH/g resulted in the production of FAME including calcium of 565 ppm.