Biodiesel production from oil-rich feedstock: A neural network modeling

Biodiesel produced from oil-rich feedstocks is known as a green replacement for conventional petroleum diesel. Transesterification is the common method used for biodiesel production. Hence, in this contribution, neural network modeling and least square support vector machine (LSSVM) modeling were used to predict the transesterification of castor oil with methanol to form biodiesel. Also, genetic algorithm was used for the optimization of predictive model. Input and output parameter of predictive models for the prediction of biodiesel production yield and estimation of the efficiency of biodiesel production are catalyst weight (C), methanol-to-oil molar ratio (MOR), time (S), temperature (T), and fatty acid methyl ester (FAME) yield, respectively. Proposed LSSVM modeling predicts biodiesel production yield or FAME yield within ±2% relative deviation with a high value of coefficient of determination (0.99583) and a low value of absolute deviation (1.27) in which the mentioned statistical parameters represent the accuracy and robustness of the model.     

Accurate modeling of biodiesel production from castor oil using ANFIS

Research for finding alternative fuel sources has been concluded that the renewable fuels such as biodiesel can be used as an alternative to fossil fuels because of the energy security reasons and environmental benefits. In this contribution, transesterification of castor oil with methanol to form biodiesel has been modeled by using artificial neural network fuzzy interference system (ANFIS) approach. Methanol to oil molar ratio, catalyst amount (C), temperature (T), and time (S) were used as input parameters and fatty acid methyl ester yield was used as output parameter for modeling the efficiency of biodiesel production from castor oil. Obtaining low value of absolute deviation (2.2391), high value of R-squared (0.98704), and other modeling results proves that ANFIS modeling is an effective approach for biodiesel production from castor oil. In conclusion, comparison between our model and other previous predictive models reported in open literature indicates the priority of our model.     

Optimization of transesterification process parameters of castor oil ethanolysis using response surface methodology-based genetic algorithm

Castor oil is unusual oil that is predominantly composed of ricinoleic acid. In the present study, castor oil biodiesel was produced from castor oil with bio-alcohol (ethanol) via a transesterification process. Also, this study investigates the influence of transesterification process parameters, i.e., reaction temperature, catalyst (sodium ethoxide) concentration, and ethanol:castor oil molar ratio on the yield of castor oil ethyl ester. The experiments are carried our as per a central composite design. A second-order response surface model was developed to predict the yield of castor oil ethyl ester as a function of transesterification process parameters. The developed models indicated that the predicted values are well in agreement with the experimental results. Finally, optimization of transesterification process parameters was carried out using a response surface methodology-based genetic algorithm. The optimization results indicated a reaction temperature of 41°C, catalyst concentration of 1.25% w/w of oil, and ethanol to oil molar ratio of 18.42 for achieving a higher yield of castor oil ethyl ester of 93.9%.     

Optimization of ethanolic transesterification ultrasound‐assisted from oil mixtures utilizing Box‐Behnken design

Biodiesel is an alternative renewable fuel in the world energy matrix, originating from animal fats and vegetable oils from grains, such as the castor bean cultivated by family farmers in the Brazilian semiarid region. However, the production of biodiesel has some disadvantages. For example, it is difficult to use the same types of oil/fat all year round. In addition, the use of methanol in the biodiesel synthesis and agitation process results in a high consumption of energy. Given this background, this article proposes an alternative biodiesel synthesis using castor oil and peanut oil mixtures, ultrasound‐assisted in an ethylic route. The experimental conditions were optimized utilizing a Box‐Behnken design. The response variable was a biodiesel yield. In this work, it was possible to reduce the ratio of alcohol to oil and thus reduce the energy consumption and increase the mass yield. This permitted the generation of biofuel with lower production costs. Finally, the response surface methodology leads to operational conditions more suitable for the production of biodiesel. In this work, the best conditions were obtained using 0.50% catalyst concentration, 50/50 castor:peanut oil rate, and 5:1 alcohol:oil ratio. These were moderate and suitable conditions for the synthesis of biodiesel in comparison with the works found in the literature, reaching a high yield of 97.93%.     

Toward prediction of kinematic viscosity of biodiesel using a robust approach

Especially by using a renewable source of fuels such as biodiesel, a large number of high-quality researches have been performed on the reduction of pollution released from fossil fuels. Transesterification process is a common way for the production of biodiesel from vegetable oil, animal fat, and algae oil in the presence of alcohol and catalyst. Viscosity is one of the important physical fuel properties used in the selection of biodiesel. Experimental measurement of viscosity is a time-consuming task. Hence, in this contribution, applicability and performance of two artificial neural network-based models named least square support vector machine (LSSVM) and genetic algorithm-radial basis function (GA-RBF) for the prediction of kinematic viscosity of biodiesel were investigated. Root-mean-square error, coefficient of determination (R²), and average absolute relative deviation of each modeling were reported for each LSSVM and GA-RBF models. Modeling results show that the proposed LSSVM model is more accurate and robust than GA-RBF model.     

Biodiesel production from castor oil using potassium hydroxide as a catalyst: Simulation and validation

The key objective of the present research is to optimize and investigate the biodiesel production from ricinuscommunis (castor) oil using microwave-assisted hybrid transesterfication process under various conditions such as microwave power, treatment time, ethanol:oil ratio and catalyst concentration (KOH). Response surface methodology (RSM) coupled with four factors with a three-level Box–Behnken response surface design (BBD) was employed to model the transesterfication technique. The obtained results were analyzed by analysis of variance (ANOVA) and a second-order polynomial model was developed to study the interactive effect of process factors on biodiesel production. Derringer’s desired function methodology was used for the optimization and optimum conditions for maximizing the biodiesel production. Under optimum conditions, the predicted biodiesel production was found to be 95% with a desirability value of 0.998. The fuel properties of the produced biodiesel were compared with the ASTM D6751 standards.     

Does biodiesel make sense?

In several countries biodiesel blending programs have been implemented looking for reduction in fossil fuel dependence and environmental benefits, including climate change mitigation. The current global biodiesel production, from different fatty raw materials, reaches about 6 billion liters per year and represents 10% of whole biofuel production. Nevertheless, in many cases the actual advantages of biodiesel production and usage are not clearly evaluated. Essentially, the feasibility of biodiesel production can be determined by its efficiency in solar energy conversion, as indicated by agro-industrial productivity and energy balance parameters, which expresses a relative demand of natural resources (land and energy) to produce biofuel. Taking into account the Brazilian conditions, in this paper an assessment of biodiesel production is presented, comparing four different productive systems. According to this evaluation, soybean and castor are limitedly feasible, whereas tallow and palm oil represent more suitable alternatives. The selection of an efficient productive system is crucial for the rationality of biodiesel production.     

Biodiesel production from waste cooking oil using heterogeneous catalysts and its operational characteristics on variable compression ratio CI engine

In the present work, the optimum biodiesel conversion from waste cooking oil to biodiesel through transesterification method was investigated. The base catalyzed transesterification under different reactant proportions such as the molar ratio of alcohol to oil and mass ratio of catalyst to oil was studied for optimum production of biodiesel. The optimum condition for base catalyzed transesterification of waste cooking oil was determined to be 12:1 and 5 wt% of zinc doped calcium oxide. The fuel properties of the produced biodiesel such as the calorific value, flash point and density were examined and compared to conventional diesel. The properties of produced biodiesel and their blend for different ratios (B20, B40, B60, B80 and B100) were comparable with properties of diesel oil and ASTM biodiesel standards. Tests have been conducted on CI engine which runs at a constant speed of 1500 rpm, injection pressure of 200 bar, compression ratio 15:1 and 17.5, and varying engine load. The performance parameters include brake thermal efficiency, brake specific energy consumption and emissions parameters such as Carbon monoxide (CO), Hydrocarbon (HC), Oxides of Nitrogen (NOx) and smoke opacity varying with engine load (BP). Diesel engine's thermal performance and emission parameters such as CO, HC, and NOx on different biodiesel blends demonstrate that biodiesel produced from waste cooking oil using heterogeneous catalyst was suitable to be used as diesel oil blends and had lesser emissions as compared to conventional diesel.     

Thermoanalytical characterization of castor oil biodiesel

The castor oil seed has 47–49% of oil. Biodiesel obtained from castor oil has a lower cost compared to the ones obtained from other oils, as due its solvability in alcohol transesterification occurs without heating. The use of biodiesel will allow a reduction on the consumption of petroleum-derived fuels minimizing the harmful effects on the environment. This work wants to provide a thermoanalytical and physical-chemistry characterization of castor oil and biodiesel. Biodiesel was obtained with methyl alcohol and characterized through several techniques. Gas chromatography indicated methyl ester content of 97.7%. The volatilization of biodiesel starts and finishes under inferior temperatures than the beginning and final volatilization temperatures of castor oil. Biodiesel data are very close to the volatilization temperatures of conventional diesel.     

Quality analysis studies on biodiesel production of neochloris oleoabundans algae

The petroleum fuels play a major role in industry, agriculture, and transport besides meeting out many other basic human needs. However, fossil fuels are limited in quantity and are depleting day by day as the consumption is increasing very rapidly. Biodiesel is one such fuel in which there is a lot of hope. In the recent past, biodiesel received considerable attention as a renewable fuel. In India, it has not been possible to produce biodiesel from edible oils since the same is very scarce. Hence, the scope of opting to non-edible oils from plants as raw material for biodiesel production recently gained momentum. This paper presents the production of biodiesel from nonedible, Neochloris oleoabundans oil and its characterization. The studies were carried out on transesterification of oil with methanol, sodium hydroxide, and Sodium methoxide as catalyst for the production of biodiesel. The process parameters such as catalyst concentration, reaction time, and reaction temperature were optimized for the production of Neochloris oleoabundans oil biodiesel. The biodiesel yield of 95.15% was noticed at optimal process parameters.     

Production of biodiesel from castor oil using iron (II) doped zinc oxide nanocatalyst

The depletion of fossil fuels has caused the price of petroleum to rise remarkably and created need for alternative energy such as biodiesel. In the present study, the biodiesel was produced from castor oil using ferromagnetic zinc oxide nanocomposite as heterogeneous catalyst for transesterification reaction. Single phase of nanocatalyst were confirmed by X-Ray Diffraction analysis. The spherical shape of the aggregated nanocatalyst was observed in Scanning Electron Microscopy. Magnetic properties were analysed using vibrating sample magnetometer. Atomic Force Microscopic analysis revealed the larger surface area and roughness of nanocatalyst. The biodiesel yield of 91% (w/w) was obtained in 50 min at 55 °C with 14 wt % catalyst loading and 12:1 methanol/oil ratio and was confirmed by Gas chromatograph with Mass Spectrometer. The result showed that the iron (II) doped ZnO nanocatalyst is a promising catalyst for the production of biodiesel via heterogeneous catalytic transesterification under milder reaction conditions.     

Alkaline-catalyzed transesterification of Silurus triostegus Heckel fish oil: Optimization of transesterification parameters

The present work reports the production of biodiesel from Silurus triostegus Heckel fish oil (STFO) through alkaline-catalyzed transesterification by using potassium hydroxide (KOH) as an alkaline catalyst with methanol. Chemical and physical properties of the extracted oil were determined. It was found that STFO has a low acid value (1.90 mg KOH/g oil); hence no pre-treatment such as acid esterification is required to produce the biodiesel. The influence of the experimental parameters such as KOH concentration (0.25–1.0% w/w of oil), methanol to oil molar ratio (3:1, 6:1, 9:1 and 12:1), reaction temperature (32, 45 and 60 °C), reaction duration (30, 60, 90 and 120 min), type of the catalyst (potassium or sodium hydroxide) and step multiplicity (single- and two-step transesterification) on the yield of the biodiesel were investigated. The maximum biodiesel yield (96%) was obtained under the optimized parameters of the transesterification (KOH 0.50% w/w, 6:1 methanol to oil, at 32 °C for 60 min). The properties of the produced biodiesel were found to conform with the ASTM standard, indicating its suitability for internal combustion engines. Blending of the produced biodiesel with petro diesel with various volume percentages was investigated as well.     

Artificial neural networks used for the prediction of the cetane number of biodiesel

Cetane number (CN) is one of the most significant properties to specify the ignition quality of any fuel for internal combustion engines. The CN of biodiesel varies widely in the range of 48–67 depending upon various parameters including the oil processing technology and climatic conditions where the feedstock (vegetable oil) is collected. Determination of the CN of a fuel by an experimental procedure is a tedious job for the upcoming biodiesel production industry. The fatty acid composition of base oil predominantly affects the CN of the biodiesel produced from it. This paper discusses the currently available CN estimation techniques and the necessity of accurate prediction of CN of biodiesel. Artificial Neural Network (ANN) models are developed to predict the CN of any biodiesel. The present paper deals with the application of multi-layer feed forward, radial base, generalized regression and recurrent network models for the prediction of CN. The fatty acid compositions of biodiesel and the experimental CNs are used to train the networks. The parameters that affect the development of the model are also discussed. ANN predicted CNs are found to be in agreement with the experimental CNs. Hence, the ANN models developed can be used reliably for the prediction of CN of biodiesel.     

Computational modeling of biodiesel production using supercritical methanol

Renewable fuels such as biodiesel are introduced as promising environmental friendly fuels and they can be applied as alternative fuels instead of fossil fuels. In the present study, a modeling study based on statistical learning theory was investigated by the least square support vector machine (LSSVM) approach for non-catalytic biodiesel production in supercritical methanol. This model can estimate the biodiesel yield as a function of temperature, pressure, reaction time, and Methanol/oil ratio. The results indicated that the suggested LSSVM model was a satisfactory model to predict biodiesel yield that was confirmed by a high value of R² (0.9961) and low value of absolute deviation (1.17%). In addition, our model has been compared with another previous Artificial neural network (ANN)-based model and great estimations of both models were proved.     

Performance evaluation of a diesel engine fueled with methyl ester of castor seed oil

In this investigation, castor methyl ester (CME) was prepared by transesterification using potassium hydroxide (KOH) as catalyst and was used in four stroke, single cylinder variable compression ratio type diesel engine. Tests were carried out at a rated speed of 1500 rpm at different loads. Straight vegetable oils pose operational and durability problems when subjected to long term usages in diesel engines. These problems are attributed to high viscosity, low volatility and polyunsaturated character of vegetable oils. The process of transesterification is found to be an effective method of reducing vegetable oil viscosity and eliminating operational and durability problems. The important properties of methyl ester of castor seed oil are compared with diesel fuel. The engine performance was analysed with different blends of biodiesel and was compared with mineral diesel. It was concluded that the lower blends of biodiesel increased the break thermal efficiency and reduced the fuel consumption. The exhaust gas temperature increased with increasing biodiesel concentration. The results proved that the use of biodiesel (produced from castor seed oil) in compression ignition engine is a viable alternative to diesel.     

Production and evaluation of biodiesel from mixed castor oil and waste chicken oil

Biodiesel was developed from an unconventional feedstock, i.e. an equivalent blend of castor bean and waste chicken oil through the alkaline-catalyzed transesterification with methanol. The process variables including the alkaline catalyst concentration, methanol to oil molar ratio, reaction temperature, reaction time, and the alkaline catalyst type were investigated. The highest yield of biodiesel (97.20 % ~ 96.98 % w/w ester content) was obtained under optimum conditions of 0.75 % w/w of oil, 8:1 methanol to oil molar ratio, 60°C temperature, and a duration of 30 min. Properties of the produced biodiesel satisfied those specified by the ASTM standards. The results thus indicated that the suggested blend oils are suitable feedstock for the production of biodiesel. The process was found to follow pseudo first-order kinetics, and the activation energy was found to be 8.85 KJ/mole.     

Spray characteristics of emulsified castor biodiesel on engine emissions and deposit formation

Castor plants are a common wild poisonous plant in Asia, and especially a weed seen across Taiwan. Due to its high viscosity and water content, straight castor oil cannot be used as a fuel for DI engine. Transesterification and emulsion technologies have been utilized to improve the spray characteristics of castor oil. Without heat, the castor biodiesel (CBD) completes the transesterification reaction under ambient temperature. Gas chromatography indicates that the CBD yield rate is 97% or above. After long-term biodiesel generator test, the emulsified castor biodiesel (EBD) leads to the problem of engine deposition. Thus, this study aimed to investigate the EBD spray characteristics on DI engine emission and deposit formation. A constant-volume bomb was established to analyze the biodiesel spray characteristics under elevated temperature. A biofuel deposit simulator was developed to solve the EBD deposit problem. Thermal gravimetric analysis, Fourier transformation infrared spectroscopy, and scanning electron microscope were utilized to analyze the EBD deposit formation mechanisms. The experimental results indicated that biodiesel generator operated on EBD can improve the fossil diesel emissions. The high NO_X emission of CBD was solved by water-biodiesel emulsion technology. The biofuel deposit simulator provided some potential deposit control additives for EBD during the laboratory research stage. Without changing the engine structure, when the injection pressure was increased by 5–10%, the optimum combination was 82.8% of castor biodiesel, 15% of water, 2% of bioethanol, and 0.2% of composite surfactant Span-Tween.     

Castor oil transesterification reaction: A kinetic study and optimization of parameters

In this paper, parameters affecting castor oil transesterification reaction were investigated. Applying four basic catalysts including NaOCH₃, NaOH, KOCH₃ and KOH the best one with maximum biodiesel yield was identified. Using Taguchi method consisting four parameters and three levels, the best experimental conditions were determined. Reaction temperature (25, 65 and 80 °C), mixing intensity (250, 400 and 600 rpm), alcohol/oil ratio (4:1, 6:1 and 8:1) and catalyst concentration (0.25, 0.35 and 0.5%) were selected as experimental parameters. It was concluded that reaction temperature and mixing intensity can be optimized. Using the optimum results, we proposed a kinetic model which resulted in establishing an equation for the beginning rate of transesterification reaction. Furthermore, applying ASTM D 976 correlation, minimum cetane number of produced biodiesel was determined as 37.1.     

Castor bean cake residues upgrading towards high added value products via fast catalytic pyrolysis

Castor oil is a vegetable oil obtained by pressing the seeds of the castor oil plant (Ricinus communis). Its production leads to high volumes of solid residues, the castor bean cakes. The main objective of this study was to investigate the potential of these castor bean cakes as a valuable source for production of high added value products such as bio-fuels and renewable chemicals. The upgrading of the castor bean cakes was attempted via thermochemical processes; specifically fast thermal and catalytic pyrolysis. Initially thermal pyrolysis of two different castor cakes and one type of castor stalks took place in a fixed bed fast pyrolysis reactor. The best feed was chosen for catalytic pyrolysis testing where industrially available microporous and one mesoporous catalyst were studied. Mass balances and products characterization via elemental analysis and two dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS) in the case of the liquid products allowed for the estimation of the catalytic effect in each case.     

Properties of biodiesel oils formulated using different biomass sources and their blends

Biodiesel is an alternative diesel fuel which can be obtained from the transesterification of vegetable oils with simple alcohols. This process decreases the viscosity, density and flash point of the raw material. The biodiesel molecular structure, consisting of linear esters, allows similar physical–chemical properties compared to mineral diesel oil. Some important properties of the oil, such as viscosity, melting point, thermal stability and cetane index can be directly related to the chemical composition of the biomass source that was used. It is therefore possible to anticipate which property values will be obtained for each biodiesel produced from a specific vegetable oil, relating them to the chemical nature of the starting vegetable oil. The objective of this study is to evaluate the properties of biodiesel oils obtained from different biomass sources (castor, soybean, cotton, and canola) and their binary blends prepared in concentration ranges between 20 and 80%vol. Each sample was analyzed for viscosity, specific gravity and iodine index. The proper formulation to meet the European specifications for biodiesel (DIN – 14214) using those sources of biomass is presented and discussed.