Transesterification of Soybean Oil Catalyzed by Calcium Hydroxide which Obtained from Hydrolysis Reaction of Calcium Carbide

Calcium carbide residue (CCR) was investigated in transesterification reaction of triglycerides to determine its viability as a solid catalyst for biodiesel synthesis. Literature survey showed that CCR has never been studied as a solid catalyst in the transesterification of triglyceride. The scope of the study includes the effects of CCR calcination temperature, calcination time, the alcohol/oil molar ratio, the catalyst amount (wt % of oil) and the reaction time. The relationship between chemical composition and catalytic activity of waste cement was also investigated. These CCR catalysts, thermally activated at 600 °C, can give rise to fatty acid methyl esters (FAME) purity higher than 99.5%, after 3 h of reaction, when oil/methanol molar ratio of 1/12 and 1 wt % of the catalyst were employed. Application of CCR as catalyst for biodiesel production in this study may not only provide a cost‐effective and environment friendly way of recycling CCR waste but also reduce hopefully the cost of biodiesel production.     

棉籽现场碱催化转酯化联产生物柴油和无毒棉粕

通过棉籽现场碱催化转酯化联产生物柴油和无毒棉粕,考察了棉仁中水的质量分数、粒径对产物中脂肪酸甲酯（FAME）的质量分数和棉粕中游离棉酚（FG）质量分数的影响;对反应过程中的醇油摩尔比、反应时间、催化剂用量、反应温度进行了单因素和正交实验考察。实验得到的反应适宜条件为,棉仁含水量在1.92%左右,棉仁粒径小于0.335mm,反应醇油摩尔比135∶1,反应3h,甲醇中氢氧化钠浓度0.10mol/L,反应温度30℃。在上述反应条件下,反应产物中甲酯的质量分数可达97%,棉粕中游离棉酚的质量分数为0.031%,低于FAO规定的国际标准。     

新型碱性离子液体催化酯交换合成生物柴油

两步法合成了吗啉阴离子型碱性离子液体1-丁基-3-甲基吗啉盐Im,经 ¹H-NMR和FT-IR分析确认了离子液体中间体的结构,并通过阴离子交换得到碱性离子液体,对该离子液体在酯交换制备生物柴油反应中的催化性能进行了研究。结果表明,该碱性离子液体Im具有较高的酯交换催化活性,在60 ℃、催化剂用量为3%、醇油物质的量比为6.5：1.0、反应2 h的条件下,产物脂肪酸甲酯（FAME）含量可达95.80%。而且该离子液体的催化稳定性较好,重复使用5次后仍有较高的催化活性。     

Clean synthesis of biodiesel over solid acid catalysts of sulfonated mesopolymers

FDU-15-SO₃H, a solid acid material prepared from the sulfonation of FDU-15 mesoporous polymer, has been demonstrated to serve as an efficient catalyst in the esterification of palmitic acid with methanol as well as in the transesterification of fatty acid-edible oil mixture. FDU-15-SO₃H achieved an acid conversion of 99.0% when the esterification was carried out at 343 K with a methanol/palmitic acid molar ratio of 6:1 and 5 wt% catalyst loading. It was capable of giving 99.0% yield of fatty acid methyl esters (FAME) when the transesterification of soybean oil was performed at 413 K and the methanol/oil weight ratio of 1:1. FDU-15-SO₃H was further applied to the transesterification/esterification of the oil mixtures with a varying ratio of soybean oil to palmitic acid, which simulated the feedstock with a high content of free fatty acids. The yield of FAME reached 95% for the oil mixtures containing 30 wt% palmitic acid. This indicated the sulfonated mesopolymer was a potential catalyst for clean synthesis of fuel alternative of biodiesel from the waste oil without further purification.     

超声作用下KF/CaO催化酯交换反应制备生物柴油

等体积浸渍法制备了KF/CaO固体碱催化剂,用于催化大豆油与甲醇酯交换反应制备生物柴油,在反应体系中引入超声作为辅助条件。研究表明,KF/CaO催化活性高。在超声的辅助作用下,酯交换反应速率加快,生物柴油的收率提高。实验考察了反应条件对产品中脂肪酸甲酯含量的影响。醇油摩尔比为12∶1,反应温度65℃,催化剂与大豆油的质量比为3%,反应1 h,超声频率20 kHz,超声声强1.01 W/cm2,在此反应条件下,产品中脂肪酸甲酯的质量分数达到99.6%。     

Coupling transesterifications for no-glycerol biodiesel production catalyzed by calcium oxide

In this study, a method consisting in coupling transesterifications for no-glycerol biodiesel production catalyzed by CaO was put forward. The transesterification between rapeseed oil and methanol was greatly improved by integrating glycerol and dimethyl carbonate (DMC) transesterification. From this result, it was found that the high fatty acid methyl ester (FAME) yield of 92.6% (with ultra-traces of glycerol as a by-product) was obtained at 65 °C under normal pressure, which is as high as the previously reported supercritical DMC method for no-glycerol biodiesel production at a reaction temperature of 350 °C and under pressures up to 17.8 MPa. Moreover, this new method has high water tolerance, and a yield of over 82% of FAME is still achieved in the presence of 0.2% of water. The optimized reaction conditions, such as the molar ratio of DMC to methanol, the catalyst dosage and the reaction time, were investigated to produce high-quality biodiesel. The fuel properties determined and discussed in light of EN 14214 (European standards) demonstrate that the biodiesel produced using this new method has good flow properties with a cloud filter plugging point of –10 °C and a pour point of –9.4 °C. Furthermore, the amount of free glycerol was found to be as low as 0.018% in the biodiesel obtained directly from this new method without any further processing. The results of this study indicate the feasibility of producing quality biodiesel fuels without glycerol by coupling transesterifications.     

The Obtaining Biodiesel from Used Vegetable Oil and Animal Waste Oil by Two Stages Transesterification Reaction

The biodiesel was obtained from used vegetable oil (UVO) and animal waste oil (AWO) by the two stages transesterification reaction. Also chemical and technical properties of feed and products were determined. Conditions of transesterification reaction for each of the oil samples were determined as a result of several sets of experiments. The suitable conditions of transesterification reaction were the following. Hereto a molar ratio of oil: methanol: catalyst was 1: 6: 1/40, for 30 min, at temperature of 600°C. To obtain biodiesel directly by the one stage transesterification, in case of using UVO sample, when the acidity number of feed oil had to less than 3 mg KOH/g. The biodiesel from UVO and AWO was prepared by mixing 5, 10, 20% of volume in the summer and winter diesel fuel. However, the product from mixture of UVO and winter diesel fuel met the technique requirements both of winter and summer diesel fuel, but the product from mixture of AWO and summer diesel fuel did not satisfy technical requirements of diesel fuel.     

Optimization of process conditions for biodiesel production over CaO–Al<Subscript>2</Subscript>O<Subscript>3</Subscript>/ZrO<Subscript>2</Subscript> catalyst using response surface methodology

CaO–Al₂O₃/ZrO₂ mixed oxide catalyst was prepared using free-solvent method. The catalyst was characterized using X-ray diffraction, BET surface area, acidity index (obtained by titration method), and scanning electron microscopy (SEM). With calcium aluminate and calcium zirconate been successfully formed, the mix exhibited small crystal size, high acidity, and large surface area, pore size, and pore volume, making it a catalyst of choice for biodiesel production. The activity of catalyst was evaluated in the course of esterification of oleic acid as well as transesterification of waste cooking oil (WCO) into biodiesel. Based on a four-variable central composite design (CCD), response surface methodology (RSM) was used to optimize effective variables on oleic acid conversion. The optimum yield of 94.68% was obtained at the following set of optimum conditions: reaction temperature of 120 °C, methanol/oleic acid molar ratio of 15.64, catalyst concentration of 2.94 wt%, and reaction time of 4 h; the result was in excellent agreement with the predicted values. Furthermore, under the optimum conditions, the catalyst succeeded to convert 93.48% of WCO into biodiesel.     

固体碱催化剂K_2CO_3/Al_2O_3的制备及其催化餐饮废油制生物柴油的性能

采用浸渍法制备了K2CO3/Al2O3固体碱催化剂,考察了活性组分负载量、焙烧温度、焙烧时间等制备条件对催化剂在催化餐饮废油合成生物柴油的酯交换反应中催化活性的影响,并对其进行了FT-IR、XRD、TG-DTG、SEM和BET表征分析。实验结果表明,所制备的催化剂在催化餐饮废油合成生物柴油的酯交换反应中表现出良好的活性,在活性组分K2CO3负载量为50%、焙烧温度500℃、焙烧时间3 h的条件下制备的催化剂催化酯交换反应时,生物柴油产率可达86.70%。催化剂表征结果显示,K2CO3/Al2O3催化活性是因K2CO3与Al2O3经高温焙烧产生新的晶相有关。催化剂重复使用4次,生物柴油产率仍在75%以上。制得的生物柴油产品质量达到国家生物柴油B100标准。     

Magnetic recyclable eggshell-based mesoporous catalyst for biodiesel production from crude neem oil: Process optimization by central composite design and artificial neural network

A magnetically recyclable eggshell-based catalyst (MKEC) was synthesized to circumvent saponification during the conversion of neem, Jatropha, and waste cooking oils (free fatty acid, 2.3–6.6%) to biodiesel. The characterization results indicated that MKEC had a mesoporous structure with the pore width of 3.24 nm, a specific surface area of 128 m²/g, and a pore volume of 0.045 cm³/g. The results confirmed that the MKEC is more tolerant to fatty acid poisoning than calcined eggshell. The effects of process parameters for maximum fatty acid methyl ester (FAME) content were evaluated by central composite design (CCD) and artificial neural network (ANN). The experimental FAME content of 94.5% was achieved for neem oil with a standard deviation (SD) of 0.68, which was in reasonable agreement with predicted values (CCD, 96.9%; ANN, 95.9%; SD, 0.73). The reusability studies showed that the mesoporous catalyst can be reused efficiently for five cycles without much deterioration in its activity.     

多频超声反应槽连续强化酸化油酯交换制备生物柴油研究

以平均酸值高达33.07 mgKOH/g不可食用的廉价酸化油为原料,利用自行设计的多频超声溢流槽连续强化酯交换反应生物柴油生产装置,先后经预酯化、酯交换两步反应,高效、低耗的制备生物柴油。主要考察了室温下物料流量(停留时间)、超声功率、超声频率及组合、KOH用量、醇油物质的量比对酯交换反应的影响及单位产品能耗。结果表明,多频组合超声辐射比单频更有利于生物柴油的制备;预酯化后的油料在流量为25 L/h(物料停留时间为54 min),催化剂(KOH)用量为1.2%(质量分数),醇油物质的量比为6∶1和各反应槽功率为200 W的条件下,甲酯产率达96.83%。50 L废弃酸化油能制得符合国标GB19147—2009的生物柴油48L,整个生物柴油制备过程总耗时和总耗电量仅为8.667 h、5.42 kWh。     

Alkali Hydrothermal Synthesis of Na0.1Ca0.9TiO3 Nanorods as Heterogeneous Catalyst for Transesterification of Camelina Sativa Oil to Biodiesel

Orthorhombic perovskite Na_0.1Ca_0.9TiO₃ nanorods were synthesized at low calcination temperature via alkali hydrothermal synthesis. The synthesized nanorods exhibits a square based prism morphology, with a width and length of 200–500 nm and 2–3 μm respectively. The structural, textural and basic characteristics of the catalyst were examined by SEM, TEM, XRD and BET. The growth direction of the nanorods was confirmed to be along the long symmetry [110] zone axis and the exterior surfaces are found to be polar (110) and (002) with either Ti or Ca exposed in those facets. The catalytic activity of the nanorods was investigated for the transesterification of the low-input Camelina Sativa oil and methanol to give the fatty acid methyl ester (FAME). Effects of important reaction parameters such as methanol to oil molar ratio, catalyst dosage, reaction temperature and reaction time on oil conversion were examined. Optimized biodiesel yield of 93 % was achieved with catalyst dosage of 6 % w/w, methanol to oil molar ratio of 36:1 at reaction temperature of 60 °C for 8 h.     

Transesterification of palm oil using supercritical methanol with co-solvent HCFC-141b

The transesterification of palm oil in supercritical methanol has been investigated without using any catalyst. HCFC-141b was used as co-solvent to reduce the molar ratio of methanol to palm oil under the milder conditions. The reaction was carried out in a flow-type tubular reactor. The residence time was fixed at 40 min. When the molar ratio of methanol to palm oil was set to 20:1 at 325 °C and 35 MPa, the optimum molar ratio of methanol to co-solvent was found to be 20:1. Addition of HCFC-141b increased FAME production even at the lower molar ratio of methanol to palm oil. In addition, a similar FAME content was obtained under the milder conditions (5 MPa lower pressure) compared with conditions without co-solvent at higher pressure. The role of HCFC-141b in the transesterification reaction under supercritical conditions was investigated.     

Effect of Bio-based Catalyst in Biodiesel Synthesis

A cost-effective and environmentally friendly biodiesel synthesis has drawn attention in recent research activities. Used cooking oil which is known as waste is used in this study. The objectives of this research were to study an effect of biobased-catalyst which is used as supporting catalyst in simultaneous ozonolysis and transesterification for biodiesel synthesis and to study the effect of two steps process in biodiesel synthesis. The bio-based catalyst used in this process was empty palm bunch ash which was used as supporting catalyst for KOH. Two steps reaction were designed, the first step was run in a reactor at 30 °C with a continuous supply of ozone gas for 3 hours to cleave the unsaturated fatty acids at the double bonds. The second step was a follow up process after the first step without a supply of ozone gas, the temperature was increased up to 60 °C and the reaction continue for two hours. The second step aimed to convert saturated fatty acid which was not yet fully converted at the first step. Results of this study showed that 1.5% of KOH gave better performance in producing short chain methyl esters compared to 1% of KOH in the first step process at various percent weight of ash. The highest short chain methyl esters and long chain methyl esters produced in the first step process were 85.722 mg/liter and 655.286 mg/liter respectively, which was used 17.3 weight % ash and 1.5 weight % KOH. Short chain methyl esters were produced as a result of unsaturated fatty acid cracked by ozonolysis. It is confirmed that a simultaneous ozonolysis and transesterification occurred in the first step process. In conclusion, the presence of bio-based catalyst as supporting catalyst for KOH to produce higher total methyl esters has been effective. The second step process in this experiment was not effective since the effect of reaction time can enhance the hydrolysis of esters as a reverse reaction of transesterification, resulted in loss of esters.     

Fast Biodiesel Production with One-Phase Reaction

The feasibility of fatty acid methyl ester (FAME) as a co-solvent used to increase the mass transfer between oil and methanol was investigated. FAME, as the co-solvent, does not require additional separation after the reaction because it is the end product of the reaction. To examine intermediate phenomena during the transesterification of soybean oil, the agitation speed was controlled at a slow rate. When the molar ratio of oil to methanol was 1:6 at 0.8wt.% of KOH to oil, oil was at the bottom layer, and methanol and the catalyst were at the top layer. Under the slow agitation process, the contact surface became initially darkened with the production of FAME and glycerol. After a few minutes, the entire top layer became dark. The top layer, containing methanol, KOH, FAME, and glycerol, fell to the bottom layer and then formed the one-phase system. When 0, 5, and 10 wt.% of FAME to oil was initially introduced to the reaction mixture, the FAME content rapidly increased with the FAME concentration level. After forming the one-phase system, the rate of increase of the FAME content was very slow. The time required for the formation of the one-phase system decreased with the amount of FAME and KOH and with temperature.     

Comparison and optimisation of biodiesel production from <Emphasis Type="Italic">Jatropha curcas</Emphasis> oil using supercritical methyl acetate and methanol

In this study, biodiesel has been successfully produced by transesterification using non-catalytic supercritical methanol and methyl acetate. The variables studied, such as reaction time, reaction temperature and molar ratio of methanol or methyl acetate to oil, were optimised to obtain the optimum yield of fatty acid methyl ester (FAME). Subsequently, the results for both reactions were analysed and compared via Response Surface Methodology (RSM) analysis. The mathematical models for both reactions were found to be adequate to predict the optimum yield of biodiesel. The results from the optimisation studies showed that a yield of 89.4 % was achieved for the reaction with supercritical methanol within the reaction time of 27 min, reaction temperature of 358°C, and methanol-to-oil molar ratio of 44. For the reaction in the presence of supercritical methyl acetate, the optimum conditions were found to be: reaction time of 32 min, reaction temperature of 400°C, and methyl acetate-to-oil molar ratio of 50 to achieve 71.9 % biodiesel yield. The differences in the behaviour of methanol and methyl acetate in the transesterification reaction are largely due to the difference in reactivity and mutual solubility of Jatropha curcas oil and methanol/methyl acetate.     

CaO-MgO@CoFe_2O_4磁性固体碱的制备及其大豆油酯交换反应催化性能

以草酸盐为前驱体采用两步法制备了一种以CaO-MgO作为活性组分,以CoFe_2O_4作为磁核的磁性固体碱催化剂,并用于大豆油与甲醇的酯交换反应合成生物柴油。对制备的磁性固体碱催化剂进行了磁滞回线、X-射线衍射(XRD)、CO_2-TPD及透射电镜(TEM)表征。考察了不同核壳物质的量比、焙烧温度、反应温度、反应时间、醇油物质的量比以及催化剂用量等因素对大豆油转化为生物柴油产率的影响。结果表明,采用核壳物质的量比为1∶6、焙烧温度为700℃所制备的CaO-MgO@CoFe_2O_4催化剂,当醇油物质的量比为12、催化剂用量为大豆油质量的1.0%时,在65℃下反应时间3 h,生物柴油收率高达97.1%。该催化剂具有较好的重复利用性能,重复利用四次后生物柴油的收率仍可达90%。     

Application of Flying Jet Plasma for Production of Biodiesel Fuel from Wasted Vegetable Oil

Biodiesel, a good partial or total substitute for petrodiesel, is a renewable clean burning fuel which can be produced from transesterification of vegetable oils and animal fats with an alcohol in presence of a catalyst. Since the feedstock costs in this process constitutes more than 70 % of the overall cost, use of wasted vegetable oil (i.e. consumed cooking oil) for biodiesel production is a big challenge in terms of cost reduction and environmental impacts. Nonetheless, the content of residues in the wasted vegetable oil, formed during frying, is a major drawback could be faced in this direction. In this research, we applied an unconventional design of flying jet dielectric barrier discharge plasma torch to treat several specimens of wasted cooking oil collected from different resources before transesterification. In other experiments, the jet plasma itself was used to catalyze the reaction process. The examined plasma torch was found more feasible than conventional DBD reactor design in terms of gas and power consumptions. Upon inducting plasma treatment, the transesterification process resulted in higher biodiesel yield, lower reaction time and easier product separation than the conventional path. Upon catalyzing the reaction by the sole jet plasma effect, the biodiesel content of saturated methyl esters was higher than conventional tranesterification. Also, the yield and properties were found within commercial standards.     

Utilisation of Non-Edible Source (Pongamia pinnata Seeds Shells) for Producing Methyl Esters as Cleaner Fuel in the Presence of a Novel Heterogeneous Catalyst Synthesized from Waste Eggshells

Waste eggshells were considered for synthesising a precursor (CaO) for a heterogeneous catalyst, further impregnated by alkali caesium oxide (Cs₂O). The following techniques were used to characterise the synthesised catalysts: X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (CO₂-TPD). The synthesised catalyst revealed its suitability for transesterification to produce biodiesel. The biodiesel production process was optimised, and it showed that the optimal biodiesel yield is 93.59%. The optimal set of process parameters is process temperature 80 °C, process time 90 min, methanol-to-oil molar ratio 8 and catalyst loading 3 wt.%. It has been found that the high basicity of the catalyst tends to give a high biodiesel yield at low methanol-to-oil ratio 8 when the reaction time is also less (90 min). The fuel properties of biodiesel also satisfied the standard limits defined by ASTM and the EN standards. Thus, the synthesised catalyst from waste eggshells is highly active, improved the biodiesel production conditions and PPSS oil is a potential nonedible source.     

Synthesis of micronized CaO assisted by NH4HCO3 with Ca(OH)2 and its application in heterogeneously catalyzing transesterification reaction for producing biodiesel

Micronized CaO with pores was synthesized by calcining the reaction product CaCO₃ from NH₄HCO₃ and Ca(OH)₂. Scanning electron microscopy, X‐ray diffraction, energy dispersive X‐ray spectroscopy, X‐ray fluorescence, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller analysis were used to characterize CaO, which confirmed that after calcining at 800°C for 2 hr, CaCO₃ was completely converted into porous micronized CaO with a surface area of about 7.295 m²/g and a particle size of 0.5–1.5 μm. The porous CaO microparticles were used as heterogeneous catalysts for producing biodiesel from transesterification of soybean oil and methanol. The influences of reaction time, calcined temperature, and reusability of CaO were explored. The experiments showed that CaO has high catalytic activity for transesterification reaction, and the yield of biodiesel reaches more than 98% under the conditions of methanol/oil mole ratio of 9, and the catalyst amount (catalyst/oil) of 3% after reaction for 2.5 hr. The CaO catalyst can be recycled easily and it also has the advantage of low pollution. Simple synthetic route, low cost, high catalytic activity, good reusability, and great potential for industrialization are the advantages of the porous micronized CaO catalyst that was proposed in this work.