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

In this study, transesterification of soybean oil to biodiesel using SrO as a solid base catalyst was studied. The reaction mechanism was proposed and the separate effects of reaction temperature, molar ratio of methanol to oil, mass ratio of catalyst to oil and repeated experiments were investigated. The results showed that the yield of biodiesel produced with SrO as a catalyst was in excess of 95% at temperatures below 70 °C within 30 min. SrO had a long catalyst lifetime and could maintain sustained activity even after being repeatedly used for 10 cycles. The results proved that transesterification of soybean oil to biodiesel using SrO as a catalyst is a commercially viable way to decrease the costs of biodiesel production.     

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.     

负载型固体碱催化合成甲酯生物柴油的研究

采用浸渍法制备了Na2CO3/高岭土负载型固体碱催化剂,用于催化大豆油与甲醇酯交换反应制备甲酯生物柴油。考察了反应时间、催化剂用量、反应温度和醇油摩尔比对酯交换反应转化率的影响,并通过单因素试验确定了最优工艺条件。结果表明:反应时间4 h、反应温度60℃、催化剂用量3%和醇油摩尔比12∶1条件下,酯交换反应转化率达到90.5%。     

Active phase of calcium oxide used as solid base catalyst for transesterification of soybean oil with refluxing methanol

For developing a process of biodiesel production with environmental benignity, much interest has been focused on solid base catalysts such as calcium oxide for transesterification of vegetable oils with methanol. In this paper, the active phase of calcium oxide was investigated by characterizing the catalyst collected after achieving the conversion of edible soybean oil into its methyl ester at reflux of methanol in a glass batch reactor. Calcium oxide combined with the by-produced glycerol, so that calcium diglyceroxide was a major constituent of the collected catalyst. The absence of calcium methoxide was clear from the spectrum of solid-state ¹³C-NMR. The chemical change of calcium oxide was not observed, when the yield of FAME reached 30%. The collected catalyst was not as active as the fresh one (calcium oxide), but was reused without any deactivation. In order to identify the active phase of the collected catalyst, we prepared calcium diglyceroxide by immersion of calcium oxide with refluxing methanol in the presence of glycerol. Calcium diglyceroxide prepared as the reference sample was as active as the collected catalyst in the transesterification, and was tolerant to air-exposure.     

Rape oil transesterification over heterogeneous catalysts

This work studies the application of KNO₃/CaO catalyst in the transesterification reaction of triglycerides with methanol. The objective of the work was characterizing the methyl esters for its use as biodiesel in compression ignition motors. The variables affecting the methyl ester yield during the transesterification reaction, such as, amount of KNO₃ impregnated in CaO, the total catalyst content, reaction temperature, agitation rate, and the methanol/oil molar ratio, were investigated to optimize the reaction conditions.The evolution of the process was followed by gas chromatography, determining the concentration of the methyl esters at different reaction times. The biodiesel was characterized by its density, viscosity, cetane index, saponification value, iodine value, acidity index, CFPP (cold filter plugging point), flash point and combustion point, according to ISO norms. The results showed that calcium oxide, impregnated with KNO₃, have a strong basicity and high catalytic activity as a heterogeneous solid base catalyst.The biodiesel with the best properties was obtained using an amount of KNO₃ of 10% impregnated in CaO, a methanol/oil molar ratio of 6:1, a reaction temperature of 65 °C, a reaction time of 3.0 h, and a catalyst total content of 1.0%. In these conditions, the oil conversion was 98% and the final product obtained had very similar characteristics to a no. 2 diesel, and therefore, these methyl esters might be used as an alternative to fossil fuels.     

甲醇钠催化地沟油制备生物柴油研究

以浓硫酸为催化剂,高酸值地沟油与甲醇酯化反应降酸的最优工艺条件为:n(甲醇):n(地沟油)=9:1,m(浓硫酸):m(地沟油)=1.1％,反应温度60℃,反应时间5h.制备生物柴油的最优工艺条件为:以甲醇钠为催化剂,反应时间2h,反应温度65℃,n(甲醇):n(地沟油)=7:1,m(甲醇钠):m(地沟油)=0.8％.制...     

Production of biodiesel from soybean oil catalyzed by attapulgite loaded with C4H5O6KNa catalyst

Biodiesel is a green, safe, renewable alternative fuel, which is of great significance to solving the problem of energy shortage and environmental pollution. A series of solid base catalysts were prepared with the support of attapulgite (ATP), the load of C₄H₅O₆KNa by impregnation method, and were used to catalyze transesterification of soybean oil with methanol to biodiesel. The activities of prepared catalysts were investigated compared to pure ATP. The optimal conditions for the catalyst preparation were investigated: molar ratio of Na: ATP was 1.7: 1 and calcination temperature was 400 °C. The prepared catalysts were characterized by several techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, N₂ adsorption-desorption measurements, X-ray diffraction and the Hammett indicator method. The prepared solid base catalyst can be separated from reaction system effectively and easily. The effects of the molar ratio of methanol to oil, reaction temperature and amount of catalyst on the biodiesel yield were investigated. The experimental results showed that a 22: 1 molar ratio of methanol to oil, 10.0% of catalyst amount, 65 °C of reaction temperature and 3.0 h of reaction time gave the best results. The catalyst has longer lifetime and maintained sustained activity after being used for five cycles.     

新型固体碱铝酸钙催化剂用于生物柴油的制备研究

采用化学合成法制备了铝酸钙固体催化剂,并将其用于菜籽油与甲醇酯交换反应的研究.考察了酯交换反应的条件,实验结果表明,当醇/油摩尔比为15:1,催化剂质茸分数6%,反应温度65℃,搅拌速率270 r/min,反应时间3 h,甲酯的收率为89.05%.产物和催化剂固液分离简单容易,铝酸钙固体催化剂具有较好的稳定性,连续使用7次,甲酯的收率均在87.00%以上.同时采用Hammett指示剂法、XRD、BET等手段对铝酸钙同体催化剂进行了表征.     

Production of biodiesel through transesterification of Jatropha oil using KNO3/Al2O3 solid catalyst

The purpose of the work to study biodiesel production by transesterification of Jatropha oil with methanol in a heterogeneous system, using alumina loaded with potassium nitrate as a solid base catalyst. Followed by calcination, the dependence of the conversion of Jatropha oil on the reaction variables such as the catalyst loading, the molar ratio of methanol to oil, reaction temperature, agitation speed and the reaction time was studied. The conversion was over 84% under the conditions of 70 °C, methanol/oil mole ratio of 12:1, reaction time 6 h, agitation speed 600 rpm and catalyst amount (catalyst/oil) of 6% (w). Kinetic study of reaction was also done.     

Ca-Mg-Al类水滑石催化大豆油甲醇酯交换制备生物柴油

采用不同前驱体,用过饱和共沉淀法制备了两种Ca-Mg-Al类水滑石,并考察了其用于催化大豆油甲醇酯交换制备生物柴油的性能。结果表明,由草酸钙为前驱体制备的Ca-Mg-Al类水滑石表现出更高的催化活性,在反应温度65℃、醇油物质的量比12:1、催化剂用量为大豆油质量的4%和反应时间180min的最佳条件下,酯化率可达84.71%。催化剂重复利用3次,仍保持较高活性。     

Microwave irradiation-assisted transesterification of soybean oil to biodiesel catalyzed by nanopowder calcium oxide

This study examined the effect of a heterogeneous base catalyst on the transesterification of soybean oil assisted by microwave irradiation. The results showed that nanopowder calcium oxide (nano CaO) was very efficient in converting soybean oil to biodiesel, and microwave irradiation is more efficient than the conventional bath for biodiesel production. However, the water content of methanol can not improve the conversion rate catalyzed by nano CaO.The suitable reaction conditions that can reach a 96.6% of conversion rate were methanol/oil molar ratio, 7:1; amount of catalyst used, 3.0 wt.%; reaction temperature, 338 K; and reaction time, 60 min. The biodiesel produced is within the limits prescribed by the standard of EN-14214.     

固体碱催化黄连木籽油制备生物柴油

制备了K2CO3/Mg(A l)O固体碱催化剂,适宜制备条件为:K2CO3负载量30%、在700℃下焙烧4 h。用比表面积测定仪、X射线衍射仪、红外光谱仪对其进行了表征。以黄连木籽油为原料,开展了酯交换法制备生物柴油的研究,考察了主要影响因素:醇油摩尔比、催化剂用量、反应时间和反应温度对酯交换反应的影响,得到的酯交换反应适宜条件为:以黄连木籽油0.01 mol计,醇油摩尔比12∶1、催化剂用量为黄连木籽油质量的4.0%、反应时间2.5 h、反应温度68℃。在该条件下生物柴油的收率可达99%以上。催化剂经4次循环使用,生物柴油收率仍可保持在96%以上。用FTIR1、HNMR对所制备的产品进行了表征,证明产品中含有饱和脂肪酸甲酯和不饱和脂肪酸甲酯。     

Dolomite as a heterogeneous catalyst for transesterification of canola oil

In this study, the catalytic activity of dolomite was evaluated for the transesterification of canola oil with methanol to biodiesel in a heterogeneous system. The influence of the calcination temperature of the catalyst and the reaction variables such as the temperature, catalyst amount, methanol/canola oil molar ratio, and time in biodiesel production were investigated. The maximum activity was obtained with the catalyst calcined at 850 °C. When the reaction was carried out at reflux of methanol, with a 6:1 molar ratio of methanol to canola oil and a catalyst amount of 3 wt.% the highest FAME yield of 91.78% was obtained after 3 h of reaction time.     

叔丁醇共溶剂用于制备生物柴油的研究

利用叔丁醇作为共溶剂可使棕榈油、甲醇和催化剂形成均相体系,用于酯交换反应制备生物柴油,可以缩短反应时间。实验以棕榈油为原料,氢氧化钠为催化剂,在带夹套的玻璃反应器内进行反应。考察了共溶剂质量分数、催化剂质量分数、反应温度、醇油摩尔比等因素对生物柴油产率的影响,获得了最佳反应条件。实验结果表明,当叔丁醇质量为棕榈油质量的11.6%,催化剂质量为油质量的1.0%,反应温度为60℃,醇油摩尔比为6∶1时,反应2 m in后生物柴油产率达到了90%。     

Continuous production of biodiesel from cottonseed oil and methanol using a column reactor packed with calcined sodium silicate base catalyst☆

Sodium silicate and that calcined at 400 °C for 2 h were used to catalyze the transesterification of cottonseed oil with methanol. Calcined sodium silicate(CSS) catalyst exhibited much higher catalytic activity and stability. A maximum biodiesel yield of 98.9% was achieved at methanol/oil mole ratio of 12:1, reaction temperature65 °C, reaction time 3.0 h, and CSS/oil mass ratio of 2 wt%. After 7 consecutive reactions without any treatment,biodiesel yield reduced to 82.5%. Considering technological and economic feasibility, CSS base catalyst supported on θ rings was prepared for continuous transesterification. The maximum yield was 99.1% under optimum conditions(reaction temperature 55 °C, methanol velocity 1 ml·min-1, oil velocity 3 ml·min-1, and 5 tower sections). These results indicate that this new continuous biodiesel production process and apparatus present a great potential for industrial application in biodiesel.     

Heterogeneous Catalyst of Mixed K Compounds/Ca‐Al‐Graphite Oxide for the Transesterification of Soybean Oil to Biodiesel

A novel heterogeneous solid base catalyst was prepared by loading of Ca‐Al‐graphite oxide with mixed potassium salts and applied in the transesterification of soybean oil with methanol to produce biodiesel. The catalysts were characterized by Hammett indicators, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X‐ray spectrometry, and transmission electron microscopy. The effects of the methanol‐to‐oil molar ratio, catalyst amount, reaction temperature, stirring rate, and reaction time were investigated to optimize the transesterification reaction conditions. Moreover, the prepared catalyst retains its activity after being used for four cycles. In particular, the solid base catalyst can be effectively and easily separated from the reaction system, which may provide significant benefits for the development of an environmentally benign and continuous process for preparing biodiesel.     

制备活性炭负载K2CO3用于催化餐饮废油合成生物柴油

以K₂CO₃为催化剂,工业碱木质素(KL)为活性炭(AC)前体,在管式电阻炉中经一步共混活化(K₂CO₃/KL质量比为0.6、活化温度800℃、N₂流量100cm³/min、活化时间2h)制备K₂CO₃/AC固体碱催化剂,用于餐饮废油与甲醇的酯交换反应合成生物柴油。对制备的固体碱催化剂进行了X-射线衍射(XRD)、BET表面积及扫描电镜(SEM)表征。考察了反应温度、催化剂用量、反应时间、醇油摩尔比等因素对餐饮废油转化为生物柴油产率的影响。结果表明当反应时间2h、反应温度60℃、醇油摩尔比15:1、催化剂为原料油质量的3.0%时,生物柴油最大产率为87.5%。考查了催化剂的循环利用效果,结果表明催化剂能循环利用3次,第3次利用时生物柴油的产率仍达到80.7%。     

Biodiesel production from soybean oil using modified calcium loaded on rice husk activated carbon as a low-cost basic catalyst

Activated carbon was obtained by hydrothermal process using rice husk as raw materials. The study in our lab had been developed to produce high-quality biodiesel from soybean oil with the activated carbon-base catalyst. The polyethylene glycol (PEG 400) modified calcium loaded on the rice husk activated carbon (CaO/AC) catalyst was prepared via the dipping method and then was used as a heterogeneous solid-base catalyst to produce biodiesel. The effects of CaO/AC ratio and calcination time on catalytic performance were researched according to the yield of biodiesel, and the optimum reaction conditions for biodiesel from soybean oil via PEG 400–modified CaO/AC catalyst were evaluated. The results showed that the yield of fatty acid methyl ester (FAME) achieved 93.01% at the reaction temperature of 342 K, methanol/oil molar ratio of 10:1, and reaction time of 6 h. All in all, modified CaO/AC catalyst showed very high activity for transesterification of soybean oil and had catalytic repeated availability.     

正交实验法优选K_2O/CaO-SBA-15催化生产生物柴油工艺条件

以介孔分子筛SBA-15为载体,通过浸渍法制备固体碱催化剂K2O-SBA-15、CaO-SBA-15和K2O/CaO-SBA-15,并对其进行XRD表征。将制备的催化剂用于催化大豆油和无水甲醇制备生物柴油。按四因素三水平的正交实验设计方案进行实验,表明各因素影响程度依次为:反应时间反应温度油醇物质的量比催化剂用量。最佳反应条件:在温度为60℃时加入n(原料油)∶n(甲醇)=12∶1的反应物,加入m(催化剂)∶m(原料油)=3%的催化剂,反应3h,产率达86.97%。     

Biodiesel Production from Soybean Oil Catalyzed by Li<Subscript>2</Subscript>CO<Subscript>3</Subscript>

In the present study, we synthesized biodiesel from soybean oil through a transesterification reaction catalyzed by lithium carbonate. Under the optimal reaction conditions of methanol/oil molar ratio 32:1, 12 % (wt/wt oil) catalyst amount, and a reaction temperature of 65 °C for 2 h, there was a 97.2 % conversion to biodiesel from soybean oil. The present study also evaluated the effects of methanol/oil ratio, catalyst amount, and reaction time on conversion. The catalytic activity of solid base catalysts was insensitive to exposure to air prior to use in the transesterification reaction. Results from ICP-OES exhibited non-significant leaching of the Li₂CO₃ active species into the reaction medium, and reusability of the catalyst was tested successfully in ten subsequent cycles. Free fatty acid in the feedstock for biodiesel production should not be higher than 0.12 % to afford a product that passes the EN biodiesel standard. Product quality, ester content, free glycerol, total glycerol, density, flash point, sulfur content, kinematic viscosity, copper corrosion, cetane number, iodine value, and acid value fulfilled ASTM and EN standards. Commercially available Li₂CO₃ is suitable for direct use in biodiesel production without further drying or thermal pretreatment, avoiding the usual solid catalyst need for activation at high temperature.