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.     

Factors affecting the separation of the reaction mixture after transesterification of rapeseed oil

The most used method of biodiesel production is the transesterification of vegetable oils by a basic homogeneous catalyst. A heterogeneous reaction mixture is formed by this process which contains two phases: an ester phase and a glycerol phase. From this mixture, biodiesel is gained by sedimentation. The quality and quantity of both phases are affected by the conditions of the sedimentation process. It was studied how the conditions (independent variables: temperature of separation, amount of added water, time of sedimentation, etc.) affect the quantity and the quality of both phases (dependent variables). The Plackett–Burman statistic system was used for experiment planning. The relationship between independent and dependent variables was found and described by multidimensional linear regression. The created model allows the calculation of the optimum conditions of biodiesel production so that the quality of the biodiesel fulfills the EN 14214.     

Parametric study of biodiesel production from used soybean oil

Biodiesel, an alternative diesel fuel derived from vegetable oil, animal fat, or waste vegetable oil (WVO), is obtained by reacting the oil or fat with an alcohol (transesterification) in the presence of a basic catalyst to produce the corresponding mono‐alkyl esters. In this work, the effect of the catalyst KOH‐to‐WVO ratio, ethanol concentration, and time of reaction on the biodiesel yield were investigated. The transesterification reaction was performed at a constant temperature (35 °C) in order to minimize the cost of heating and ethanol evaporation. A 2³ complete factorial design on biodiesel yield (Y) was performed using low and high levels of operating variables: KOH concentration (9–14 g/L), ethanol concentration (30–40 vol‐%) and time (30–40 min). The complete factorial model that can be used to fit the data was determined. The model shows that interactions exist among the parameters and that the parameters, or factors, do not operate independently on the response (biodiesel yield). The highest yield was obtained in the first 30 min of reaction time. The results indicate that the highest yield was 78.5 vol‐% using a KOH‐to‐WVO ratio of 12 g/L and 30 vol‐% ethanol. The ASTM tests indicate that the biodiesel properties are within the biodiesel standard limits.     

Heterogeneous esterification of oil with high amount of free fatty acids

Frying oils have become the newest raw material for the transesterification reaction for the production of biodiesel. However, these compounds usually come with a certain amount of free fatty acids. These impurities can be transformed into esters and the production of biodiesel could be increased.The use of basic resins to perform the esterification reaction into biodiesel is studied in this work. The effect of the most relevant variables of the process such as reaction temperature, molar ratio between alcohol and oil, amount of catalyst and amount of free fatty acids fed with the oil have been analyzed. For this purpose, an ideal frying oil using oleic acid and soybean oil was made. The alcohol used was ethanol.The esterification of free fatty acid using this heterogeneous catalyst appears as a great alternative to purify frying oil; in this case, the final conversion achieved was around 80%.     

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.     

Conversion of waste cooking oil to biodiesel using ferric sulfate and supercritical methanol processes

In this comparative study, conversion of waste cooking oil to methyl esters was carried out using the ferric sulfate and the supercritical methanol processes. A two-step transesterification process was used to remove the high free fatty acid contents in the waste cooking oil (WCO). This process resulted in a feedstock to biodiesel conversion yield of about 85-96% using a ferric sulfate catalyst. In the supercritical methanol transesterification method, the yield of biodiesel was about 50-65% in only 15 min of reaction time. The test results revealed that supercritical process method is probably a promising alternative method to the traditional two-step transesterification process using a ferric sulfate catalyst for waste cooking oil conversion. The important variables affecting the methyl ester yield during the transesterification reaction are the molar ratio of alcohol to oil, the catalyst amount and the reaction temperature. The analysis of oil properties, fuel properties and process parameter optimization for the waste cooking oil conversion are also presented.     

Production of biodiesel from palm oil (Elaeis guineensis) using heterogeneous catalyst: An optimized process

Response surface methodology (RSM) based on central composite design (CCD) was used to optimize the three important reaction variables — methanol/oil molar ratio (x₁), reaction time (x₂) and amount of catalyst (x₃) for production of biodiesel from palm oil using KF/ZnO catalyst. Based on the CCD, a quadratic model was developed to correlate the reaction variables to the biodiesel yield. From the analysis of variance (ANOVA), the most influential factor on the experimental design response was identified. The predicted yield after process optimization was found to agree satisfactory with the experimental value. The optimum conditions for biodiesel production were found as follows: methanol/oil ratio of 11.43, reaction time of 9.72 h and catalyst amount of 5.52 wt%. The optimum biodiesel yield was 89.23%.     

Optimization of the production of biodiesel from soybean oil by ultrasound assisted methanolysis

This paper evaluates and optimizes the production of biodiesel from soybean oil and methanol using sodium hydroxide as catalyst. The study and optimization was carried out at low catalyst concentration (0.2 to 0.6 w/w). The reaction was carried out with application of low-frequency high-intensity ultrasound under atmospheric pressure and ambient temperature in a batch reactor. Response surface methodology (RSM) was used to evaluate the influence of methanol to oil ratio and catalyst concentration on soybean oil conversion into biodiesel. Analysis of the operating conditions by RSM showed that the most important operating condition affecting the reaction was the methanol to oil ratio, while catalyst amount showed little significance in the transesterification reaction. Total consumption of oil was obtained when alcohol to oil ratio of 9:1 and catalyst concentration of 0.2 w/w were applied.     

Study of variables affecting the synthesis of biodiesel from Madhuca Indica oil

Biodiesel derived from non‐edible Madhuca Indica oil (MIO) seems to be a better alternative to diesel oil in India. In the present work, effects of reaction variables such as mass ratio of methanol to oil, catalyst concentration, reaction time and reaction temperature on biodiesel yield were studied. The acid value of the commercially available MIO is high, and hence a two‐step process was used to produce biodiesel from MIO. In the first step, the acid value of the MIO was reduced to less than 1 mg KOH/g, using acid‐catalyzed transesterification. In the second step, the pretreated MIO was converted to biodiesel using alkaline‐catalyzed transesterification. From the experimental results, it is observed that the optimized conditions for biodiesel production are a 1 : 4 mass ratio of methanol to oil, 55 °C reaction temperature, 120 min of reaction time, and 1% sodium hydroxide catalyst. The properties of the MIO biodiesel were found to be within the biodiesel limits of the European Union. Hence, the MIO biodiesel can be used as a substitute for diesel for the sustainable development of rural areas and as a renewable fuel.     

Effects of process variables for biodiesel production by transesterification

In this study, biodiesel production from various vegetable oils by transesterification was studied, to determine the optimum conditions. Experiments were carried out by using different kinds of catalysts (sodium hydroxide, potassium hydroxide, barium hydroxide, pyrolitic coke and wood ash) and feedstocks (corn oil, sunflower oil, soybean oil, olive pomace oil and cottonseed oil) at 65 °C and an agitation speed of 1000 rpm. The neutralization step with controlled pH was performed by treatment with phosphoric acid. An experimental design was used to evaluate the effects of the parameters such as types of vegetable oils, kinds of catalysts, reaction time, alcohol/oil volumetric ratio and amount of catalyst, on the methyl ester conversion. Using response surface methodology, a quadratic polynomial equation was obtained by multiple regression analysis. It was found that catalyst concentration was the most effective parameter. Sodium hydroxide and potassium hydroxide exhibited a superior catalytic behavior, whereas pyrolitic coke and wood ash had to be used in excess amount or for prolonged reaction times. Moreover, the properties such as viscosity, density, calorific value, acid value, and refractive index of the biodiesel were measured. The tri‐, di‐, monoacylglycerols and glycerol residuals in the methyl esters produced were also quantified by GC analysis.     

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%。     

超声波法制备生物柴油

在超声波条件下,以大豆油为原料,氧化钙为催化剂,利用正交试验研究了催化剂用量、油醇比、反也时间和反应温度等对生物柴油产率的影响。南实验得最佳工艺条件为：油醇比（质量）为0．9：1,反应时间为30min,反应温度为45℃,催化剂用量为0．9％（占原料油用量的质量分数）。在该条件下制备的生物柴油收率可达96％,其凝点为-2．2℃闪点为112℃,运动粘度为3．93mm／s,其性能与0号石化柴油比较接近。     

Modelling and optimization of main independent parameters for biodiesel production over a Cu0.4Zn0.6Al2O4 catalyst using an RSM method

In this research, the modeling of Cu0.4Zn0.6Al2O4 catalysts performance and optimizing of esterification reactions were considered by the central composite design (RSM) response method. The main independent parameters of temperature, the ratio of alcohol to oil, the amount of catalyst and time duration have been considered for setting the esterification process. To access the maximum activity in the esterification process, the optimum conditions are estimated at 10.42 the molar ratio of alcohol to oil, 2.98 wt.% for the amount of catalyst at the temperature of 163.37 °C and within 4.15 hrs. Under these conditions, the conversion will be above 97.94%. These conditions have been applied to adjust the process of transesterification of waste cooking oil. The reusability of the Cu0.4Zn0.6Al2O4 nanocatalyst in the esterification reaction was investigated in this study. Employed statistical techniques and developed models can be employed as a useful tool for design, prediction, and optimization of the biodiesel production process with effective performance for various industrial applications. © 2021 Society of Chemical Industry (SCI).     

Heterogeneously Catalyzed Methanolysis of Gmelina Seed Oil to Biodiesel

The heterogeneous catalysis of transesterification of gmelina seed oil to biodiesel is evaluated. The oil was extracted from the seeds with n‐hexane by solvent extraction and characterized to determine its physiochemical properties. Response surface methodology was applied to optimize the effect of process variables on the biodiesel yield. The base‐activated clay catalyst performed as montmorillonite clay with the characteristic property of a Brønsted acid. It has an improved surface area after activation that enhanced its catalytic activity on transesterification reaction. Under optimal conditions, the biodiesel yield was 70.1 %, thus demonstrating that the model predicted well the biodiesel production.     

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.     

微波辐射下固体超强酸TiO2/SO^2-4催化葵花籽油制备生物柴油

研究了微波辐射作用下同体超强酸TiO2/SO^2-4催化葵花籽油与甲醇通过酯交换反应制备生物柴油,考察了催化剂用量、反应时间、微波功率和醇油摩尔比对酯交换反应的影响。实验结果表明,当醇油摩尔比为12：1、催化剂用量（催化剂与油的质量比）为2％、微波功率为300W、反应时间为25min时,生物柴油的收率可以达到94.3％。     

Biodiesel Synthesis from Styrax confusus Hemsl Catalyzed by S2O82−/ZrO2‐TiO2‐Fe3O4

Biodiesel has been identified as a suitable resource that can be produced from biomass such as Styrax confusus Hemsl. In the current study, biodiesel was synthesized from Styrax confusus Hemsl oil catalyzed by a magnetic solid acid heterogeneous catalyst S₂O₈^2?/ZrO₂‐TiO₂‐Fe₃O₄, which had a high recovery rate and reusability. The catalyst was prepared by co‐precipitation and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction and Brunauer, Emmett and Teller (BET) adsorption. The properties of the catalyst, including the recovery rate, usage count, magnetic susceptibility and catalytic efficiency, were studied. The results showed that the catalyst has a BET pore diameter of 1.74 nm, BET area of 7.3 m²/g, molar magnetic susceptibility of 1.83 × 10^?5 m³/kg and tetragonal structure. In addition, the influences of reaction conditions on yields of biodiesel were also discussed. A fatty acid methyl ester (FAME) yield of 90.02 % was obtained under the conditions of reaction time 1.5 h, reaction temperature 373 K, catalyst amount 5 %, and methanol‐to‐oil molar ratio 8:1. A FAME yield of 65.5 % was obtained when the catalyst was used for the fourth time.     

Obtaining and characterization of biodiesel from jupati (Raphia taedigera Mart.) oil

The search for alternative triglyceride sources for biodiesel production is a widely discussed issue in Brazil because of the initiation of the Brazilian biofuel program. The viability of biodiesel production from the oil of Raphia taedigeraMart., commonly known as jupati, is studied in this work. This paper presents the obtention and characterization of biodiesel from jupati using an ethylic route with a methane sulfonic acid reaction catalyst. The alcohol:oil molar ratio was 9:1, and the catalyst concentration was 2% of the oil mass. The yield of the process was 92% by mass, and the oil conversion into jupati ethylic biodiesel was 99.6%. The physical and chemical parameters of jupati ethylic biodiesel were within the limits set by the National Agency of Petroleum, Natural Gas and Biofuels (ANP).     

Optimization of ultrasonic-assisted heterogeneous biodiesel production from palm oil: A response surface methodology approach

The use of ultrasonic processor in the heterogeneous transesterification of palm oil for biodiesel production has been investigated. Response surface methodology was employed to statistically evaluate and optimize the biodiesel production process catalyzed by two alkaline earth metal oxide catalysts i.e. BaO and SrO. SEM, surface analysis, AAS analysis and the Hammett indicator methods were used for characterization of the catalysts. Four different variables including reaction time (10-60 min), alcohol to oil molar ratio (3:1-15:1), catalyst loading (0.5-3.0 wt.%) and ultrasonic amplitude (25-100%) were optimized. Mathematical models were developed and used to predict the behavior of the process. The models were able to accurately predict the biodiesel yield with less than 5% error for both catalysts. The basic strength of the catalysts was the main reason of their high activities. This study confirmed that the ultrasonic significantly improved the process by reducing the reaction time to less than 50 min and the catalyst loading to 2.8 wt.% to achieve biodiesel yields of above 95%. The optimum alcohol to oil ratio was found to be at 9:1 while the best amplitudes were ∼ 70 and ∼ 80% for the BaO and SrO catalysts, respectively.