Transesterification of Canola Oil to Biodiesel Using CaO/Talc Nanopowder as a Mixed Oxide Catalyst

A series of heterogeneous catalysts including different molar ratios of CaO/talc was synthesized to study the transesterification reaction of canola oil and methanol under different reaction conditions. Characterization and kinetic results revealed that the activity of this catalyst was enhanced due to the increase of CaO/talc molar ratio value leading to an improvement in the biodiesel production. Moreover, the effect of various parameters on the activity of the undertaken catalysts was studied in order to determine the optimum process conditions. Leaching measurements and the durability of the CaO/talc catalyst under several reaction cycles were evaluated and proved it to be a stable catalyst.     

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.     

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.     

Biodiesel Production Using Calcined Waste Filter Press Cake from a Sugar Manufacturing Facility as a Highly Economic Catalyst

For the first time, a low cost, high performance and environmentally friendly heterogeneous catalyst derived from waste filter press cake (FPC) from a sugar manufacturing facility was used for the production of biodiesel. This industrial waste was calcined in air at 900 °C for 2 h to convert it into an active CaO‐based catalyst (FPC‐HT). In addition, the calcium oxide nanoparticles (FPC‐NAC) were synthesized by surfactant‐hydration treatment of FPC‐HT. The synthesized catalysts were characterized by XRD, FTIR, SEM, TEM and BET analysis. These calcium oxide catalysts were used for a transesterification reaction between canola oil and methanol to produce biodiesel. The results show that the FPC‐NAC has higher catalytic activity than FPC‐HT under optimized reaction conditions. Therefore, this economic catalyst is able to catalyze the transesterification of canola oil to its methyl esters in 1.5 h with yields above 96 %.     

Transesterification of sunflower oil in a countercurrent trickle-bed reactor packed with a CaO catalyst

Transesterification of sunflower oil with methanol to form biodiesel was performed in a countercurrent trickle-bed reactor, using calcium oxide particles 1-2 mm in diameter as a packed, solid base catalyst. Although biodiesel production generally requires a reaction temperature below the boiling point of methanol to maintain a heterogeneous, liquid-liquid reaction, in the present study the reaction temperature was varied from 80 to 140 °C to confirm the progress of transesterification in a gas-liquid-solid phase reaction system. Oil droplets released from a thin tube flowed downward, while vaporized methanol flowed upward in the bed. The effects of the reaction temperature, methanol and oil flow rates, and the bed height on the FAME yield were investigated. The oil residence time in the reactor, which was controlled by changing both the oil flow rate and the bed height, had a significant effect on the FAME yield. In addition, the FAME yield increased with reaction temperature and was maximal at 373 K due to the change in residence time associated with reduced oil viscosity at higher temperatures. The FAME yield was 98% at a reaction temperature of 373 K when the methanol and oil flow rates were 3.8 and 4.1 mL/h, respectively.     

原位水热合成法制备ZSM-5/堇青石整体式催化剂

以蜂窝状堇青石为载体,采用原位水热合成法制备了ZSM-5/堇青石整体式催化剂。考察了四丙基氢氧化铵(TPAOH)含量、水硅摩尔比和晶化温度等对ZSM-5分子筛在堇青石载体上负载量的影响。结果表明:模板剂TPAOH的含量对负载量有显著影响,当摩尔比n(TPAOH)/n(SiO2)≤0.2时,改变晶化温度和水硅摩尔比均可获得较佳的分子筛负载量;当n(TPAOH)/n(Si O2)0.2时,较高的碱度导致前驱体溶胶的溶解,使分子筛多在溶液中晶化,显著减小分子筛在堇青石载体上的负载量。当n(TPAOH)/n(Si O2)≤0.2时,水硅比减小,ZSM-5分子筛负载量逐渐增大,最大负载量可达42.8%。晶化温度降低,分子筛的负载量和晶粒均减小。整体式催化剂用于NO的催化氧化活性研究表明,堇青石载体上分子筛的负载量越高,整体式催化剂的比表面积越大,催化活性越好。     

Biodiesel Production from Sunflower Oil Using K2CO3 Impregnated Kaolin Novel Solid Base Catalyst

Kaolin clay material was loaded with potassium carbonate by impregnation method as a novel, effective, and economically heterogeneous catalyst for biodiesel production of sunflower oil via the transesterification reaction. The structural and chemical properties of the produced catalysts were characterized through several analyses including the X-ray diffraction, scanning electron microscopy, Fourier-transform infrared spectroscopy, and Brunauer–Emmett–Teller specific surface area. These revealed the best catalyst for the investigated reaction among different ones prepared based upon various impregnation extent of the potassium carbonate. The influence of this parameter was examined through a comparison of the catalytic activity of differently produced catalysts. The impregnation amount of 20 wt% K₂CO₃ upon the kaolin achieved the highest catalytic activity attributed to its highest basicity. To expand upon the efficiency of transesterification, such reaction parameters including the molar ratio between methanol and oil, reactor loading of the catalyst, and time duration of the reaction were optimized. The highest yield of biodiesel over the K₂O/kaolin catalyst was around 95.3 ± 1.2%, which was achieved using the kaolin support impregnated with 20 wt% of K₂CO₃ under optimum reaction conditions of the catalyst, reactor loading of 5 wt%, reaction temperature of 65 °C, methanol:oil molar ratio of 6:1, and reaction duration time of 4 hours. Ultimately, this optimized catalyst was demonstrated to successfully withstand the aforementioned optimum criteria up to five consecutive reaction cycles while experiencing a rather negligible loss of about 10% of its activity.     

Feasibility of Palm Oil as the Feedstock for Biodiesel Production via Heterogeneous Transesterification

The production of biodiesel has become popular recently as a result of increasing demand for a clean, safe and renewable energy. Biodiesel is made from natural renewable sources such as vegetable oils and animal fats. The conventional method of producing biodiesel is by reacting vegetable oil with alcohol in the presence of a homogenous catalyst (NaOH). However, this conventional method has some limitations such as the formation of soap, usage of significant quantities of wash water and complicated separation processes. Heterogeneous processes using solid catalysts have significant advantages over homogenous methods. Currently, more than 90 % of world biodiesel is produced using rapeseed oil. The production of biodiesel from rapeseed oil is considered uneconomical, considering the fact that palm oil is currently the world's cheapest vegetable oil. Therefore, the focus of this study is to show the feasibility of producing biodiesel from palm oil using montmorillonite KSF as a heterogeneous catalyst. The heterogeneous transesterification process was studied using design of experiment (DOE), specifically response surface methodology (RSM) based on a four‐variable central composite design (CCD) with α = 2. The transesterification process variables were reaction temperature, x₁ (50–190 °C), reaction period, x₂ (60–300 min), methanol/oil ratio, x₃ (4–12 mol mol^–1) and the amount of catalyst, x₄ (1–5 wt %). It was found that the conversion of palm oil to biodiesel can reach up to 78.7 % using the following reaction conditions: reaction temperature of 155 °C, reaction period of 120 min, ratio of methanol/oil at 10:1 mol mol^–1 and amount of catalyst at 4 wt %. From this study, it was shown that montmorillonite KSF catalyst can be used as a solid catalyst for biodiesel production from palm oil.     

Biodiesel production using supercritical methanol/carbon dioxide mixtures in a continuous reactor

Fatty acid methyl esters (biodiesel) were produced by the transesterification of triglycerides with compressed methanol (critical point at 240 °C and 81 bar) in the presence of solid acids as heterogeneous catalyst (SAC-13). Addition of a co-solvent, supercritical carbon dioxide (critical point at 31 °C and 73 bar), increased the rate of the supercritical alcohols transesterification, making it possible to obtain high biodiesel yields at mild temperature conditions. Experiments were carried out in a fixed bed reactor, and reactions were studied at 150-205 °C, mass flow rate 6-24 ml/min at a pressure of 250 bar. The molar ratio of methanol to oil, and catalyst amount were kept constant (9 g). The reaction temperature and space time were investigated to determine the best way for producing biodiesel. The results obtained show that the observed reaction rate is 20 time faster than conventional biodiesel production processes. The temperature of 200 °C with a reaction time of 2 min were found to be optimal for the maximum (88%) conversion to methyl ester and the free glycerol content was found below the specification limits.     

Synthesis of Biodiesel from Canola Oil Using Heterogeneous Base Catalyst

A series of alkali metal (Li, Na, K) promoted alkali earth oxides (CaO, BaO, MgO), as well as K₂CO₃ supported on alumina (Al₂O₃), were prepared and used as catalysts for transesterification of canola oil with methanol. Four catalysts such as K₂CO₃/Al₂O₃ and alkali metal (Li, Na, K) promoted BaO were effective for transesterification with >85 wt% of methyl esters. ICP-MS analysis revealed that leaching of barium in ester phase was too high (~1,000 ppm) when BaO based catalysts were used. As barium is highly toxic, these catalysts were not used further for transesterification of canola oil. Optimization of reaction conditions such as molar ratio of alcohol to oil (6:1–12:1), reaction temperature (40–60 °C) and catalyst loading (1–3 wt%) was performed for most efficient and environmentally friendly K₂CO₃/Al₂O₃ catalyst to maximize ester yield using response surface methodology (RSM). The RSM suggested that a molar ratio of alcohol to oil 11.48:1, a reaction temperature of 60 °C, and catalyst loading 3.16 wt% were optimum for the production of ester from canola oil. The predicted value of ester yield was 96.3 wt% in 2 h, which was in agreement with the experimental results within 1.28%.     

离子型树脂催化酯交换反应的研究

一种线型强碱型阴离子型树脂与无机材料SiO2的共混物QAPPES/SiO2被制备了出来,作为催化剂应用于大豆油与甲醇的酯交换反应中,制备脂肪酸甲酯.实验结果表明,QAPPES/SiO2在较低的温度下对脂肪酸甘油酯与甲醇的酯交换反应表现出较高的催化活性:在快速的搅拌下,60℃、醇油体积比3:1、催化剂加入量与豆油加入量数值上的关系为1:4(质量/体积)、反应时间为8 h,在此条件下油脂的转化率可达到76%.不同因素对反应影响作用的大小依次为反应物醇油比(体积)>反应搅拌速度＞反应温度＞反应催化剂加入量＞反应时间.     

废旧油脂的精制及酯交换制备生物柴油的研究

采用除杂、脱水、萃取、脱色等操作对废油脂如废煎炸油、地沟油、橡胶籽油进行了精制;对大豆油和精制处理前后的上述废油脂的各种物理化学性质进行了测定和评价;采用共沉淀法制备了Mg/Al类水滑石,450℃焙烧得到复合氧化物并以其催化各种油脂和甲醇合成生物柴油;分别用1H NMR法和仲裁法分析对比酯交换反应的产率。结果表明,大豆油制备生物柴油的产率高达96.9%,而精制后的地沟油、煎炸油和橡胶籽油制备生物柴油的收率分别达38.6%、40.2%和82.0%,可有效降低生物柴油生产成本。尤其是橡胶籽油,有望成为大豆油的替代原料用于生物柴油生产工业。     

Transesterification of Vegetable Oil to Biodiesel using a Heteropolyacid Solid Catalyst

A clean, facile, and ecologically friendly method for the production of biodiesel has been developed. A solid acid, namely the heteropolyacid (HPA) Cs_2.5H_0.5PW₁₂O₄₀, has been used as a heterogeneous catalyst for the production of biodiesel from Eruca sativa Gars. oils (ESG oil) with methanol at a certain temperature. A study for optimizing the reaction conditions such as the reaction time, temperature, the oil to methanol ratio, the amount of catalyst, and the usage times of the catalyst, has been performed. The Cs_2.5H_0.5PW₁₂O₄₀ heterogeneous acid catalyst shows almost the same activity under the optimized reaction conditions as compared to a conventional homogeneous catalyst such as sodium hydroxide or sulfuric acid, and can easily be separated from the products and can be used for several more runs. The most important features of this catalyst are that the catalytic activity is not effected by the content of free fatty acids and content of water in the vegetable oil and that the esterification can occur at a lower temperature (room temperature) and be finished within a shorter time. The results illustrate that the Cs_2.5H_0.5PW₁₂O₄₀ is an excellent, water‐tolerant and environmentally benign solid acid catalyst for the production of biodiesel. The fuel properties of ESG biodiesel were found to be in agreement with the ASTM standard.     

Reaction Kinetics of Soybean Oil Transesterification Using Heterogeneous Metal Oxide Catalysts

Homogeneous acid or base catalysts dissolve fully in the glycerol layer and partially in the fatty acid methyl ester (biodiesel) layer in the triglyceride transesterification process. Heterogeneous (solid) catalysts, on the other hand, can prevent catalyst contamination making product separation much simpler. In the present work, the transesterification kinetics of five different solid catalysts with soybean oil is presented. It is found that heterogeneous catalysts require much higher temperatures and pressures to achieve acceptable conversion levels compared to homogeneous catalysts. Subsequent to preliminary investigations, transesterifications were conducted for selected high performance solid catalysts, i.e., MgO, CaO, BaO, PbO, and MnO₂ in a high pressure reactor up to a temperature of 215 °C. The yield of the fatty acid methyl esters and the kinetics (rate constant and order) of the reaction are estimated and are compared for each catalyst.     

Optimization of Process Variables for Biodiesel Production Using the Nanomagnetic Catalyst CaO/NaY‐Fe3O4

Due to decreasing oil resources, alternative fuels such as biodiesel are required. The nanomagnetic catalyst CaO/NaY‐Fe₃O₄ was synthesized and used for biodiesel production from canola oil. The structure of the catalysts was characterized by X‐ray diffraction, field emission scanning electron microscopy, Brunauer‐Emmett‐Teller method, Fourier transform infrared spectroscopy, and vibrating sample magnetometer method. To optimize the influence of the operating variables, such as the methanol/canola oil molar ratio, the amount of catalyst, and the reaction time, on the yield of transesterification reaction, an experimental design was applied based on the Box‐Behnken method. The optimum values of these variables were predicted by the cubic model and were in excellent agreement with the experimental results.     

Biodiesel Production from Rubber Seed Oil by Transesterification Using a Co‐solvent of Fatty Acid Methyl Esters

Rubber seed oil (RSO) is a high‐potential feedstock for the production of biodiesel fuel (BDF) in Asia. Transesterification using fatty acid methyl esters (FAMEs) as co‐solvents was developed for BDF production from RSO with high content of free fatty acids (FFAs). The homogeneous system (FAMEs/triglyceride/methanol) was attained when the FAME content was more than 30 wt %. After esterification of RSO, the crude RSO obtained was transesterified with FAMEs as a co‐solvent. The quality of BDF with high FAME content satisfied the criteria of the EN 14214/JIS K2390 standards. These results suggest that FAMEs converted from FFAs can be applied as a co‐solvent and, thus, reused for BDF production.     

Dynamics and Control of a Biodiesel Transesterification Reactor

Biodiesel transesterification reactors resemble the heart of any biodiesel manufacturing plant. These reactors involve a highly complex set of chemical reactions and heat transfer characteristics. The high nonlinearity inherent in the dynamics of these reactors requires an efficient process control algorithm to handle the variation of operational process parameters and the effect of process disturbances efficiently. In this work, a multi‐model adaptive control strategy is considered for achieving the goal mentioned above. In order to implement the adaptive controller, a rigorous mechanistic model of the biodiesel transesterification reactor was developed and validated with published experimental results. The validated model was analyzed for stability and nonlinearity. The analysis revealed that the system is stable. However, its high nonlinearity necessitates an advanced control strategy to be considered. The input‐output relationship between the effective process variables was studied and the control system synthesis revealed a two‐by‐two control system. Two adaptive control loops were then designed and tuned to optimize the performance of the controller. Finally, a comparison with conventional controllers revealed the superiority of the new control system in terms of set‐point tracking and disturbance rejection. The results of this work prove that an adequately designed adaptive control system can be used to improve the performance of the transesterification reactor.     

Preparation and Characterization of CaO/MgO Catalyst and Its Application for Transesterification of n-Butyl Acetate with Methanol

This work reports the synthesis and characterization of CaO/MgO mixed oxide with different CaO/MgO mass ratios prepared by the co-precipitation method in a basic medium and subsequent calcination of the precursors. These mixed-oxide materials were characterized by XRD, FT-IR, SEM, and BET. The alkalinity of samples was determined by CO₂ temperature-programmed desorption (CO₂-TPD). Results show that the CaO/MgO samples contained mixed crystalline phases of cubic CaO and hexagonal MgO species. Decreasing the CaO/MgO ratio resulted in low average pore diameter and enhanced BET surface area.

Transesterification of n-butyl acetate with methanol was studied using a CaO/MgO catalyst at atmospheric pressure and 95°C, a model reaction to evaluate the potential of these catalysts for biodiesel production. The highest activity was found for a CaO/MgO mass ratio of 8:2 with conversion percentage of 83. The effects of calcination temperature, reaction time, reaction temperature, methanol/n-butyl acetate molar ratio, and catalyst recycling were investigated.     

Heterogenization of the biodiesel synthesis catalysis: CaO and novel calcium compounds as transesterification catalysts

Although CaO is one of the most studied basic heterogeneous catalysts for the synthesis of biodiesel, there are important issues that have been addressed by only a few research groups and that deserve further investigation. This is the case of the difficulties introduced by the poisoning of CaO upon exposure to ambient air and the role played by CaO-glycerol complexes on the catalytic performance. The purpose of this work is to provide new information on these issues in order to contribute to a better understanding of the underlying phenomena. Four commercial CaO samples have been considered to investigate their activation and stability under reaction conditions. In addition, calcium glyceroxide, and, for the first time, calcium glycerolate, have been synthesized and compared with the materials obtained from the commercial samples. The solids have been characterized with special emphasis on the assessment of their basic properties. The catalytic tests revealed big differences between the performance of the commercial solids that were substantially reduced after calcination and, specially, Ca-glyceroxide formation during reaction. Ca-glycerolate was the most resistant catalyst to ambient air although it was characterized by a low initial activity. Ca-glyceroxide could be reutilized for at least 5 reaction cycles without activity loss.     

NaOH/PAM催化剂对合成生物柴油的影响

大麻籽油和甲醇经NaOH/PAM催化合成生物柴油,本实验在醇油比固定的情况下考察了催化剂的碱含量、催化剂用量对酯交换转化率的影响、碱量及反应时间分别对转化率和皂化百分数的影响,采用红外光谱技术对催化剂进行分析,确定了较适宜的反应条件.结果表明:实际碱量随NaOH添加量的增加而增加；催化剂用量增加,原料油转化率增加；反应时间的增加,原料油转化率曲线增加到一定水平后趋于平缓；较适宜的反应条件为PN-4催化剂用量3％,反应时间为60 min.