Soybean Biodiesel Research Articles

Biodiesel production from cagaite seeds (Eugenia dysentericaDC) oil: An alternative for biofuel production

AbstractIn the present work, cagaite (Eugenia dysenterica DC.) seed oil was studied as a potential inedible raw material for biodiesel production. The oil was extracted using a Soxhlet extractor and the fatty acids acyl esters that make up biodiesel were obtained by alkaline transesterification using sodium hydroxide. The influence of reaction parameters was also evaluated: molar ratio, time, and amount of catalyst. The conversion of fatty acids into fatty acid methyl esters (FAME), which make up biodiesel, was calculated using Nuclear Magnetic Resonance Spectroscopy (1HNMR) spectra. In a 30 min reaction period, the molar ratio of oil to methanol was 1:4, resulting in a conversion of 63.57%. However, when the molar ratio was increased to 1:8, the conversion reached 81.74% during the same 30 min reaction period. After 60 min of reaction, additional increases in conversion were observed when molar ratios of 1:4, 1:6, and 1:8 were used. Under these conditions, the conversions achieved were 92.08%, 98.24%, and 98.78%, respectively. The physico‐chemical properties were evaluated and the results showed that cagaite seed oil biodiesel was similar to soybean biodiesel, which is the most commonly produced biodiesel in Brazil. It was thus an important substitute for soybean biodiesel.

Assessment of oxidative stability of biodiesel and biodiesel blends

ABSTRACT This research investigates the oxidative stability of biodiesel blends produced from macauba and soybean after being stored for 45 and 90 days. The stability was evaluated through specific mass, kinematic viscosity, and water content measurements. The results showed a significant increase in water content and acidity index values during storage, particularly in the first 45 days. However, at time zero, the acidity index of all samples was below the established limit, but after 90 days of storage, only the BM100 sample remained below the limit. The fatty acid composition of macauba oil was determined by gas chromatography, and it presented 65.01% saturated fatty acids and 34.99% unsaturated fatty acids, with a higher predominance of maluric fatty acid at 36.37%. The physical-chemical characteristics of macauba oil, including acidity index, viscosity, and oxidation stability, were also determined. The acidity index of macauba oil was found to be 1.00 mg KOH/g, which is at the maximum limit for alkaline transesterification for biodiesel synthesis. The low viscosity of macauba oil (31.92 mm2/s) is justified by its composition rich in c12 uric acid, while the fatty acid composition may be responsible for the high oxidative stability. Spectroscopy in the infrared region was used to determine the chemical composition of soybean biodiesel, macauba biodiesel, and their blends.

Parkia speciosa: A basic heterogeneous catalyst for production of soybean oil-based biodiesel

A green heterogeneous catalyst was fabricated for the biodiesel synthesis via transesterification of soybean oil. The catalyst was generated by simple calcination of the biomass Parkia speciosa (Manipuri beans) at 700 °C. Characterization techniques like TGA, FT-IR, XRD, SEM, BET, TEM, STEM, EDS, XPS, and CO2-TPD were employed to analyse the catalyst. The results showed the existence of significant amount of potassium (K) with some amount of calcium (Ca) in the form of oxides and carbonates which serves as active catalytic sites for accelerating the process of transesterification. The highest biodiesel yield of 96.4 % was achieved at 40 °C, when reaction was performed for 3 h with catalyst loading of 5 wt%, 1:15 M ratio of oil to methanol and 20 wt% of co-solvent. The catalyst has also proved to be truly heterogeneous at low temperature as its efficiency remains intact even after five successive cycles. Thus, the biomass-derived catalyst can be seen as a potentially viable alternative for the conventional homogeneous catalyst.

Evaluating the sustainability of the 2017 US biofuel industry with an integrated techno-economic analysis and life cycle assessment

The United States produced more than 66.2 billion Liters of biofuel, primarily in the form of corn ethanol (61 billion Liters) and soybean biodiesel (6 billion Liters), for the transportation industry in 2017. No work currently exists that evaluates both the economic and environmental outcomes of this industry with adequate geospatial resolution and national scope. In this study, a model framework is constructed to perform Techno-Economic Analysis and Life Cycle Assessment using high-resolution input datasets to provide a granular estimation of corn ethanol and soybean biodiesel sustainability performance in most counties in the United States in 2017 (the most recent year for which data is available). Results show a total life cycle, greenhouse gas emission volume of 99.5 million Mg CO2-eq produced in 2017 by these two biofuels (94.8 million Mg from corn ethanol, and 4.7 million Mg from soybean biodiesel), excluding indirect land use change emissions. This volume corresponds to a combined carbon intensity of 65.3 gCO2-eq/MJ, which is a greenhouse gas improvement compared to petroleum-based gasoline (the carbon intensity of conventional gasoline is 93.0 gCO2-eq/MJ). However, these biofuels are produced at an additional economic cost ($6.2 billion over the displaced gas/diesel). Additionally, these biofuels generate unfavorable impacts in other environmental categories when compared to petroleum-based fuels, particularly in areas of water, land, and nitrogen intensity. This work enables stakeholders to assess the specific value of biofuels as a means of emission reduction and determine if the attained improvements are worth the associated opportunity costs.

The influence of thermal barrier coating on an LHR engine fueled by soybean biodiesel blended with various additive spectrums: Performance, combustion, and emission analysis

AbstractThe novelty of this research work deals with green synthesized nanoadditives (5% of graphene, carbon nanotubes, and carbon black), oxygenated additives (5% of n‐butanol, n‐heptane, and n‐pentanol), and then the test fuels are prepared by blending of 20% of soybean biodiesel and 70%, 80%, and 100% of premium diesel. The experimental outcomes revealed that the Nickel Chromium Aluminum (NiCrAl‐120 micron), partially stabilized zirconia, and titanium dioxide ceramic composites at about 400 microns achieve the thermal barrier coat of low heat rejection (LHR) engine parts by the air‐plasma spray method. Compared with Blend B, green synthesized carbon black (5%), premium diesel (70%), and n‐pentanol (5%) mixed soybean biodiesel (20%) fuel (Blend E) tested on the LHR engine achieved 4.90% higher brake thermal efficiency and 25.31% lower brake‐specific fuel consumption at peak load owing to the presence of an oxygenated agent (n‐pentanol) in the fuel blend, which minimizes carbon deposition. The carbon monoxide, hydrocarbon, NOx, and smoke emissions were reduced by 25.58%, 29.41%, 5.06%, and 7.75% when compared to Blend B at peak load. Then, the in‐cylinder pressure and heat release rate were found to be 4.52% and 8.87% higher for Blend E at peak load compared to Blend B. This was because the mix of oxygenated additive and carbon black bio‐based nanofuels made the combustion process go faster. These fuel blends were tested on LHR diesel engines at various load conditions.

Fungal Resistance and Leaching Behavior of Wood Treated with Creosote Diluted with a Mixture of Biodiesel and Diesel

This study evaluated the effect of biodiesel as a co-solvent with the wood preservative creosote to reduce the amount of hydrocarbon-based carrier utilized. Small blocks of wood were treated at a pilot scale using three different creosote concentrations. The diluent used was a blend of 80% soybean biodiesel and 20% petroleum diesel. The efficacy of creosote was tested against brown rot and white rot fungi. The results of the wood-block test and agar test suggested that there was no significant effect of biodiesel on the efficacy of creosote as a wood preservative. As creosote-treated wood is commonly used for railway ties, its potential impact on the surrounding environment was also assessed by studying the leaching behavior of creosote–biodiesel–diesel blend treated railway ties. Rainfall simulators were used to imitate an exposure of treated wood to a significant amount of rainfall. Wood core drilled from the exposed railway ties and leaching water samples were analyzed for the levels of polycyclic aromatic hydrocarbons (PAHs) and total petroleum hydrocarbons (TPHs). Overall, this study demonstrated that the diluent containing biodiesel had no negative effect on the performance of creosote as a wood preservative and towards the natural environment.

Comparison of the Engine Performance of Soybean Oil Biodiesel Emulsions Prepared by Phase Inversion Temperature and Mechanical Homogenization Methods

The engine performance and emission characteristics of burning emulsions of soybean oil biodiesel in a compression-ignition diesel engine prepared through the phase inversion temperature method were compared with those of neat soybean oil biodiesel and the emulsion prepared by the mechanical homogenization method. The engine torque was set constantly at 98 N·m with varying engine speeds. The experimental results show that the emulsion prepared by the method of phase inversion temperature had higher O2 and NOx emissions, a higher excess air ratio, a higher exhaust gas temperature, and a higher brake fuel conversion efficiency than the emulsion prepared by the mechanical homogenization method, which had lower CO and CO2 emissions, a lower equivalence ratio, and lower brake-specific fuel consumption. While the neat soybean oil biodiesel was found to have the lowest fuel consumption rate, brake-specific fuel consumption, and CO and CO2 emissions, it had the highest exhaust gas temperature and brake fuel conversion efficiency, NOx and O2 emissions, and excess air ratio among those three fuels. Therefore, the phase inversion temperature method is considered promising for preparing fuel emulsions as an alternative to petro-derived diesel for compression-ignition engines.

Fluorescence lifetime of endogenous fluorophores for assessing the thermal degradation of biodiesel

This work reports the potential of fluorescence lifetime data to evaluate the oxidative stability of soybean biodiesel under heating and airflow as a function of the heating time. The fluorescence decay at 420 nm for unheated soybean biodiesel showed a 3-exponential decay with lifetimes of 0.65 ± 0.04 ns (24.4% ± 0.9); 2.45 ± 0.05 ns (55.5% ± 0.9), and 8.10 ± 0.02 ns (20.1% ± 0.8). The lifetime components, as well as the mean lifetime, were influenced by heat and airflow. The data of steady-state fluorescence, UV–vis absorption, and gas chromatography-mass spectrometry (GC-MS) of biodiesel heated at 110 °C indicated a strong pairwise Pearson correlation with the mean fluorescence lifetime at 420 nm, suggesting a relationship between the concentration of major esters and the degradation of minor endogenous fluorophores (conjugated tetraenes) in biodiesel. Induction time measured by the Rancimat test corroborates the absorption, fluorescence, and chromatographic results. Therefore, our findings suggest that the formation and degradation of conjugated tetraenes could be used as fluorescence probes in steady-state and lifetime measurements to assess the thermal degradation of biodiesel.

Effect of Pilot Injection with Various Starts of Second Injection Command (SOIC2) and Fuel Injection Pressures on Gasoline Compression Ignition Combustion

This experimental study was conducted using a single-cylinder compression ignition (CI) engine with a pilot injection strategy to determine the effect of fuel injection pressure and the timing of the second start of injection (SOI2) on combustion and emission characteristics. This experiment used a mixture of 80% commercial gasoline (G80%) and 20% soybean biodiesel (B20%), by volume. The pilot injection strategy was applied with varying SOI2. Meanwhile, the first start of injection (SOI1) was constant at -350° ATDC and 900 bar fuel injection pressure. A range of fuel injection pressures from 400 to 900 bars and varied injection timing from -44 to -36 CA ATDC was applied at SOI2 to analyze the effect of injection timing and injection pressure on combustion characteristics and emissions. The increasing fuel injection pressure of GB20 in early injection timing will cause a longer ignition delay. The autoignition resistance of GB20 and the improvement of spray velocity enhance the wall wetting probability, consequently reducing the autoignition capability as fuel deposits were formed in the cylinder wall vicinity. Closer injection timing to TDC inhibits spray penetration due to higher room pressure and density, causing lower ignition delay. For GB20, 700 bar fuel injection pressure became the turning point in the ignition delay due to a lower fuel penetration velocity as a higher fuel injection pressure was applied. NOx emissions were identified as a sign of high temperature produced during combustion. The lowest CO2 emissions and the longest ignition delay appeared at the 700-bar injection pressure. Because incomplete combustion resulted in fuel deposits in the vicinity of the cylinder and temperature decrease, injection timings earlier than 40°CA BTDC initiated low thermal reaction (LTR) conditions, causing a temperature decrease during combustion.

Impact of fuel injection pressure on the common rail direct fuel injection engine powered by microalgae, kapok oil, and soybean biodiesel blend

In this paper, the viability of microalgae as a viable replacement feedstock for compression ignition engines is investigated. The characteristics of diesel fuel alternatives, including microalgae (MAME100), kapok oil (KA100), and soybean (SME100), as well as their blends with diesel, were studied. The results were used to compare the engine performance and emissions of D100, MAME100, MAME20, KA100, KA20D80, SME100, and SME20D80. The findings demonstrate that the addition of MAME20, KA20D80, and SME20D80 have been employed to assess engine output and emission. At 200 bar, the brake thermal efficiency (BTE) decreases by 2.0 % for MAME20D80, 1.5 % for KA20D80, and 2.0 % for SME20D80 as compared to D100. Specific fuel consumption (SFC) was shown to rise as KA20D80 levels rose by 3.8 %. The use of MAME20D80 and SME20D80 resulted in reductions of NOx emissions of 10.0 % and 14.2 % as well as soot emissions of 10 % and 4.0 % as compared to D100. However, employing SME20D80, the blends produce greater carbon dioxide (CO2) emissions of 11.4 %. In conclusion, a diesel engine can employ MAME20D80 and KA20D80.

Microwave-assisted one-step production of biodiesel from waste cooking oil by magnetic bifunctional SrO–ZnO/MOF catalyst

Magnetic bifunctional SrO–ZnO/MOF catalyst supported on metal-organic framework (MOF) was synthesized for one-step biodiesel production from high acid value oils. The catalyst presented both basicity (2.84 mmol/g) and acidity (0.02 mmol/g) due to active components of Sr3Fe2O6 and ZnO. MOF support increased catalyst specific surface by 3.7 times and provided Fe3O4 component for magnetic separation. The highest soybean biodiesel yield of 99.5% was obtained at 80 °C with 3 catalyst cycles. Microwave heating significantly reduced reaction time from 20 min to 5 min at 99.0% biodiesel yield and 80 °C. The catalyst was highly active and resistant to free fatty acids with biodiesel yield of 90.0% from waste cooking oil (AV of 3.3 mg KOH/g) at longer reaction time of 30 min. SrO–ZnO/MOF has potential application in biodiesel industry.

Numerical simulation of a diesel engine performance powered by soybean biodiesel and diesel fuels

BackgroundThe present study presents a 3-D numerical simulation of a direct injection diesel engine powered by base diesel oil and soybean biodiesel fuel at different load conditions. The modeling was performed using commercial computational fluid dynamics (CFD) software linked to a chemical solver. A chemical kinetic reaction mechanism was developed to simulate the combustion and fuel spray processes. Base diesel oil results were verified using a single-cylinder, 4-stroke diesel engine.ResultsThe study showed that the usage of the soybean biodiesel fuel caused a reduction in carbon monoxide (CO) and hydrocarbon (HC) emissions by about 42.38% and 41.35%, compared with base diesel and an increase in nitrogen oxides (NOx) and carbon dioxide (CO2) emissions of about 21.8% and 11.2%, respectively. Exhaust gas temperature (EGT) is reduced by an average value of 9.4%, the brake-specific fuel consumption (BSFC) is increased by an average value of 11.8% and the brake thermal efficiency (BTE) is dropped by an average value of 11.3% for soybean biodiesel fuel.ConclusionsThe CFD model showed the effect of the unsaturated fatty acid methyl esters present in soybean biodiesel on the spatial distributed values of NOx, oxygen and temperature during the combustion in engine cylinder. It was observed that the combustion of soybean biodiesel began about 3.89 CAD earlier than base diesel, and the in-cylinder peak pressure was dropped by 8.25%. Soybean biodiesel fuel was optimized by performing four starts of injection (SOI) at timings of − 18, − 16, − 15 and − 13,5 bTDC, and it was found that the combustion characteristics of soybean biodiesel are optimum at SOI = − 15 bTDC. These results indicate that the biodiesel fuel can be used as an alternative and environmentally friendly fuel in the engine without any modifications.

Production, Characterization, and Exergy Analysis of the Soybean Biodiesel Produced by Laboratory Scale

The world's hegemonic energy model is mostly based on the burning of fossil fuels. The heavy reliance on oil, coal, and natural gas for power generation as well as the pollution resulting from burning such fuels is a growing global concern. Biodiesel from the transesterification of vegetable oils is a promising alternative source for diesel engines. The ANP, National Agency of Petroleum, Natural Gas and Biofuels, regulates fuels in Brazil. In this work, soybean biodiesel was produced on a laboratory scale through an alkaline transesterification reaction. An analysis of the exegetic efficiency of the process, the physical-chemical characterization of biodiesel, and a brief discussion on the following parameters were carried out: higher and lower calorific value, water content, specific mass at 20°C, kinematic viscosity at 40°C, acidity index and oxidative stability, verifying the adequacy to the parameters of ANP Resolutions nº 45/2014 and nº 798/2019. Considering the exergetic efficiency of 63.42% and the physical-chemical characterization, despite the non-conformities in water content and oxidative stability, soybean biodiesel proved to be a satisfactory alternative for renewable fuel.

Effect of Chemical Conversion Treatment with Oxalic Acid Solution in the Corrosion Resistance of Galvanized Steel in Soybean Biodiesel with Natural Additives

Effect of Chemical Conversion Treatment with Oxalic Acid Solution in the Corrosion Resistance of Galvanized Steel in Soybean Biodiesel with Natural Additives

Synthesis of delafossite CuCrO2 via solution combustion method and its acid functionalization for biodiesel production

CuCrO2 was synthesized by solution combustion synthesis (SCS) and applied as a heterogeneous catalyst to produce soybean biodiesel. The combustion reaction was carried out using urea as a fuel, and copper (II) and chromium (III) nitrates as precursors. After the powders’ obtention, these were calcined and functionalized in an acidic medium. The powders were characterized by thermogravimetry (TG), X-ray diffraction (XRD), scanning electron microscopy (SEM), and infrared spectroscopy (IR) techniques. The TG curve revealed that the formation of the CuCrO2 in the combustion reaction remained stable up to 1000 °C. The XRD results confirmed the formation of the CuCrO2 compound. The SEM images showed that the crystallinity of the samples increased after the calcination process. The IR spectra showed the presence of delafossite characteristic bands. After the transesterification reaction, biodiesel was obtained with a yield of around 80%. Thus, catalysts based on delafossite synthesized through the combustion method and functionalized showed to be promising for the transesterification reaction of vegetable oils.

Evaluation of Oxidative Stability and Kinetic Parameters of the Cottonseed and Soybean Biodiesels by Rancimat and Differential Scanning Calorimetry Techniques

In this study, the oxidative stability of the cottonseed oil biodiesel (CB) and soybean oil biodiesel (SB) was investigated by two methodologies, Rancimat and Differential Scanning Calorimetry (DSC), using samples fresh and aged (mid-term storage condition (100 days)). The biodiesel samples were synthesized by transesterification and characterized by specific mass, kinematic viscosity, acidity value, ester content, viscosity index, and peroxide value. The activation energy (<em>E<sub>a</sub></em>), Arrhenius pre-exponential factor (<em>Z</em>), reaction order (<em>n</em>), and reaction rate at constant temperature (<em>k</em>(T)) were calculated by Borchardt and Daniels method. The results showed that oxidation affected the physicochemical properties of the biodiesel samples, especially, acidity (mg KOH/g), peroxide value (meq/1000 g), and induction period, with a decrease of around 55% for CB and 29% for SB. For kinetic parameters, the k(T) of both aged samples presented the highest values, with an increase of around 314% for SB. It was also observed that the rate constants increased with decreasing values of the induction period, in agreement with the current literature. According to the evaluation, the Borchardt and Daniels method can be recommended for a quick assessment of the biodiesel oxidation kinetic parameters.

Comparison and Storage Stability of Biodiesels from Expired oils

Transesterification of expired vegetable oils is possible by heating them with a significant amount of methanol and an acidic or basic catalyst to improve the reaction rate and yield. In this study 4 samples have been selected, including 4 types of vegetable oils, namely: soybean, sunflower, rapeseed, pumpkin seed. The operative conditions of the reaction were reaction time (4 h), catalyst concentration (1 w/wt %), and oil-to-methanol molar ratio (6:1). The parameters studied to compare the quality of biodiesel obtained by each type of compound are: yield, pH, density, acid value. The results shows that The pumpkin seed have a positive effect on increasing the yield of Soybean biodiesels as well as biodiesel blends based on Soybean, Sunflower and rapeseed. This paper examines also the degradation of several biofuels in comparison with fossil fuels (Diesel and gasoline) with different storage conditions over 9 Weeks period. The Results indicated that: High temperature combined with the lighting strongly enhances the degradation phenomenon. The acid value of biodiesel (HM) is rapidly increasing at a rate of 0.91 mg KOH/g /Week. The pH of diesel has experienced a strong decrease of 66%. In comparison with Diesel, Diesel degrades strongly and rapidly from a biodiesel in terms of Acid Value, pH and Density.

Boric acid as a hydrogen bond donor with TBAB catalyze the cycloaddition of CO2 to internal bio-epoxides under solvent-free conditions

The cycloaddition of CO2 with epoxides is regarded as one of the most efficient methods to synthesize cyclic carbonate because of the 100% atom utilization. Therefore, it is necessary to develop efficient catalysts for the synthesis of cyclic carbonates. Hydrogen bond donors (HBDs) have been widely investigated due to their ability to activate epoxides and dramatically enhance the cycloaddition process. In this study, boric acid as a cheap HBD combined with TBAB as an effective co-catalysis system for cyclic carbonates synthesis through cycloaddition of CO2 to epoxidized soybean biodiesel. 92.3% yield of cyclic carbonates product was achieved at 100 °C with 10 bar pressure of CO2 for 10 h under solvent-free conditions. To further evaluate the catalyst activity, preliminary kinetic investigations were conducted and the results showed that activation energies (Ea) of cyclic carbonate formation were different (58.5 kJ/mol for TBAB, 44.22 kJ/mol for TBAB-boric acid). The results show that boric acid as HBD can efficiently improve the yield of cyclic carbonates. Thus, the developed catalyst system provides an efficient and economical approach for the industrial production of bio-based cyclic carbonates.

The influence of Annona muricata L. peel extract as a potent source of natural antioxidant on soybean oxidation stability

Antioxidants are an alternative to prevent or retard biodiesel degradation. Soursop (Annona muricata L.) is a native tropical fruit with important antioxidant activity, besides high concentration of phenolic compounds. Peels form about 20 % of the soursop fruit composition and are usually discarded as a waste product. In this study the antioxidant potential of different peel extracts was evaluated by oxidative stability when used as an additive into soybean biodiesel. All samples were analyzed by the Rancimat® 873, using 32 experimental design. The tests were performed with biodiesel B100 with solutions extracted in different conditions, such as pH and residue concentrations. Results demonstrated that all experiments were able to increase significantly the induction period (IP), when compared to a pure biodiesel control sample, and showed similar efficiency with synthetic antioxidants (BHT). Among all experiments, each neutral and alkaline extractions presented induction periods over 8 h, achieving and surpassing the minimum allowed by European standard. However, the highest IP was found to be 10.30 h, with 3 g L-1 in neutral extraction. Results corroborate that soursop peel has a high antioxidant capacity and efficiency to improve the oxidation stability, and could be used as an inexpensive natural antioxidant to biodiesel.

Regionalized Life-Cycle Water Impacts of Microalgal-Based Biofuels in the United States.

While algal biofuels have the potential to reduce the national reliance on fossil fuels, high water consumption associated with algal biomass cultivation represents a major concern potentially compromising the sustainable commercialization of this technology. This study focuses on quantifying the water footprint (WF) and water scarcity footprint (WSF) of renewable diesel derived from algal biomass and provides insights into where algal cultivation is less water-intensive than traditional ethanol and biodiesel feedstocks. Results are generated with an engineering process model developed to predict the life-cycle water consumption, considering green, blue, and gray water, of algae facilities across the United States at a high spatiotemporal resolution. The total WFs for Florida and Arizona are determined to be 13.1 and 17.6 m3 GJ-1, respectively. The blue WF in Arizona is shown to be 8.5 times larger than in Florida, while the green WF is 4.5 times smaller, but when combined into a total WF, there is just a 26% difference between the two locations. The analysis reveals that the total life-cycle WFs of algal renewable diesel are smaller than the optimal WFs of corn ethanol and soybean biodiesel. Algal systems benefit from higher growth rates and offer the opportunity to manage wastewater streams, therefore generating smaller green and gray WFs than those of conventional biofuels. The WSF analysis identifies the Gulf Coast as the most suitable region for algal cultivation, with cultivation in the western US shown to exacerbate local water stress levels.