Properties Of Fatty Acid Methyl Esters Research Articles

FAME properties, bio-oil productivity and carbon yield coefficient of Chlorella sorokiniana grown with low and high initial nitrogen concentrations

In this work the effect of the initial nitrogen concentration on the fatty acid methyl ester (FAME) properties namely the saponification number (SN), the iodine value (IV), the cetane number (CN) and the higher heating value (HHV) of bio-oil produced by Chlorella sorokiniana was examined. Also, the lipid and protein content of the biomass of C. sorokiniana and the biomass yield were measured. Anaerobic digestate and glycerol were used to formulate the culture media. The initial concentration of atomic nitrogen varied in the four cultivations and it was equal to 108.2 mg/l, 300 mg/l, 800 mg/l and 2000 mg/l while the initial concentration of carbon was held constant and equal to 13.99 ± 0.1 g/l. As the initial nitrogen concentration was increased, the lipid content decreased while the protein content and the biomass yield increased. Fatty acids (FA) from C10:0 to C26:1 were produced, however, the fatty acids that were found in the highest percentage were C16:0, C16:1, C18:1 and C18: 2. With respect to saturation, monosaturated FA were predominant in all treatments constituting from 55.9% to 59.4% of the total FA, while significant percentages of saturated FA were produced ranging from 24.5% to about 31.1%. With respect to the chain length, medium chain FA predominate constituting from 59.5% to 81.3% of the total FA. The four measured FAME properties, with the exception of the cetane number (CN) for the No = 2000 mg, were within acceptable limits. It was shown that when the nitrogen concentration in the medium increases, while the carbon concentration remains constant, the biomass carbon yield coefficient increases substantially.

A molecular simulation study on transport properties of FAMEs in high-pressure conditions

Transport property prediction of fatty acid methyl esters (FAMEs) is essential to its utilisation as biodiesel and biolubricant which can work under high-pressure conditions. Equilibrium molecular simulation is performed to study the viscosity, diffusivity, density and molecular structure dynamics at conditions up to 300 MPa. Among the transport properties, convergence of the viscosity needs a sufficiently large number of independent replications of the simulation. The system size effect on diffusion coefficient should be taken into consideration in fitting the Stokes-Einstein relation. The capability of three different force fields on predicting transport properties is evaluated in terms of the united-atom molecular model and all-atom molecular model. The solidification of FAMEs under high pressure occurs with parallel molecular alignment. The spatial inhomogeneity results in the breakdown of Stokes-Einstein relation. A hybrid effective hydrodynamic radius is established on the linear relation between experimental viscosity and diffusion coefficient in molecular simulation. This provides a predictive method to estimate viscosity from molecular diffusion coefficient over a broad range of conditions provided that Stokes-Einstein relation applies.

Selection of microalgae strains for sustainable production of aviation biofuel

This study develops and applies the PROMETHEE-GAIA method as a new tool to select microalgae strains for aviation fuel production. Assessment involves 19 criteria with equal weighting in three aspects, namely biomass production, lipid quality, and fatty acid methylester properties. Here, the method is demonstrated for evaluating 17 candidate microalgae strains. Chlorella sp. NT8a is assessed as the most suitable strain for aviation fuel production. The results also show that unmodified biofuel from the most suitable strain could not meet all jet fuel standards. In particular, microalgae-based fuel could not satisfy the required density, heating value and freezing points of the international jet fuel standards. These results highlight the need for a broad action plan including improvement in the processing or modification of biofuel produced from microalgae and revision of the current jet fuel standards to facilitate the introduction of microalgae-based biofuel for the aviation industry.

Tunisian Opuntia stricta Seed Oil: Extraction, Characterization, and Prediction of Fatty Acid Methyl Ester Properties as Biodiesel Fuel

Tunisian Opuntia stricta Seed Oil: Extraction, Characterization, and Prediction of Fatty Acid Methyl Ester Properties as Biodiesel Fuel

Electrolytic transesterification of waste frying oil using Na+/zeolite–chitosan biocomposite for biodiesel production

Given the economic and environmental advantages of using Waste Fried Oil (WFO) as a starting material, this investigation explores the conversion of WFO to Fatty Acid Methyl Ester (FAME) via electrolysis for use in waste. In electrolysis, hydroxyl ions are generated from water in close proximity to the cathode. When hydroxyl ions react with methanol, they produce a species of nucleophilic methoxide which is the main actor in converting WFO into FAME. This study specifically investigates the effects of voltage, catalyst concentration, co solvent amount, rotation speed, and molar ratio of methanol to WFO in electrolytic transesterification converting WFO into FAME using graphite electrodes in the presence of a heterogeneous, catalytic zeolite–chitosan composite. With an alcohol to WFO molar ratio of 8:1, 1 wt% zeolite-chitosan composite concentration at 40 V in the presence of 2 wt% H2O of the whole solution at room temperature and stirrer rate of 400 rpm and reaction time of 30 min, a 96.5% yield of FAME was achieved. Characterization of physical and biodiesel fuel properties was performed using American Society for Testing and Materials (ASTM) methods. The biocomposite was characterized using Fourier Transform Infrared (FTIR), X–ray Diffraction (XRD), Transmission Electron Microscopy(TEM), Brunauer Emmett Teller(BET), Thermogravimetric analysis (TG), Scanning Electron Microscopy (SEM) and Energy Dispersive X–ray spectrometry (EDX). Finally, the physical properties of FAME produced under optimal conditions were studied using Gas Chromatography–Mass Spectrometry (GC–MS), FTIR, surface tension, and viscosity.

Measurement and modeling of thermal conductivity for short chain methyl esters: Methyl butyrate and methyl caproate

Fatty acid methyl esters (FAMEs) are the main component of biodiesels. Before the industrial application of FAMEs, it is essential to investigate the thermophysical properties of FAMEs. Thermal conductivity of fuels is used in various processes, such as the design of the heat transfer system and the determination of the temperature distribution of engines. Thus, it is of great significance to acquire accurate experimental data and develop reliable models for obtaining accurate thermal conductivity data of FAMEs. In this work, thermal conductivities of two short-chain FAMEs, methyl butyrate (MeC4:0) and methyl caproate (MeC6:0) were studied experimentally and theoretically. The thermal conductivities of these two FAMEs were measured by the transient hot-wire method at T = 303 to 523 K and p = 0.1 MPa to 15 MPa, the data were correlated as a polynomial function of temperature and pressure, the AADs are 0.38% for MeC4:0 and 0.42% for MeC6:0, respectively. Moreover, the experimental thermal conductivities agree well with the available data from literature. In addition, three classical models (Latini model, Sastri model, Liu model) were used to represent the present experimental data and the results show that Liu model with re-fitted parameters performs better in the prediction of the thermal conductivity of FAMEs, with regard to accuracy.

In Situ Transesterification of Spirulina Microalgae to Produce Biodiesel Using Microwave Irradiation

The present technology of transesterification of vegetable oils to produce biodiesel, which is suited to replace petrodiesel, has economic challenges, and therefore, alternative sources are being explored. Microalgae, a renewable, third-generation biofuel resource, have the potential to become a viable feedstock due to their high oil content and environmentally friendly nature. The present study investigates the effect of microwave irradiation on the simultaneous extraction and transesterification of algae lipids to produce fatty acid methyl ester (FAME), in a batch reaction system using sulphuric acid catalyst. In situ transesterification combines the two steps of lipid extraction and transesterification into a single step. The microwave synthesis unit comprised of a 3-neck round bottom flask inside a 1300-Watt microwave oven, fitted with a quick-fit condenser and having an external stirrer. Response surface methodology (RSM) was used to analyse the influence of process variables, dry algae to methanol ratio 1 : 4 − 1 : 14 g / ml , algae biomass to catalyst ratio 1 : 0.0032 − 1 : 0.0368 wt % , and reaction time 1 − 11 min , at 500 rpm stirring rate for in situ reaction. FAME was analysed using gas chromatography (GC). The total lipid content of Arthrospira Spirulina platensis microalgae biomass was found to be 10.7 % by weight. The algae biomass also contained proteins at 51.83 % , moisture content at 7.8 % , and ash content 14.30 % by weight. RSM gave the optimum process conditions as dry algae biomass feed to methanol wt / vol ratio of 1 : 9, catalyst concentration of 2 wt % , and reaction time of 7 minutes for a maximum FAME yield of 83.43 wt % . The major fatty acid composition of FAME was palmitic 43.83 % , linoleic 38.83 % , and linolenic 19.41 % . FAME properties obtained according to European Standards (EN 14214) and American Society for Testing and Materials (ASTM D 6751) standards were as follows: flash point 16 4 o C calorific value 32,911 kJ / kg , acid value 0.475 KOH / g , viscosity 4.45 m m 2 / s , and specific gravity 0.868 . The study showed that Arthrospira Spirulina platensis microalgae lipid FAME met the biodiesel standards (EN 14214 and ASTM D 6751) and has the potential to replace petrodiesel. Microwave irradiation increased the reaction rate resulting in a reduced reaction time of 7 minutes (as compared to 8 hours for conventional heating) and therefore was found to be a superior heating mode as compared to conventional heating.

Enhanced microbial biodiesel production from lignocellulosic hydrolysates using yeast isolates

An effort in contributing to the reduction of fossil resource dependence along with utilization of lignocellulosic wastes, will be a beneficial approach in biofuel production. These approaches will aid in sustainable waste management and will contribute to economic feasibility. This study probed the exploitation of abundant, non-edible lignocellulosic wastes such as sugarcane bagasse and rice husk as a low-cost carbon source for the cultivation of oleaginous yeast isolates and lipid accumulation, respectively. The hydrolysis of the lignocellulose was explored by steam explosion alone to reduce the inflation of toxic compounds like hydroxy methyl furfural (HMF), furfural, and acetic acid. This optimization study investigated the effects of carbon sources (sugarcane bagasse hydrolysate, rice husk hydrolysate, and commercial glucose), nitrogen sources, and pH on biodiesel production using central composite design (CCD), and achieved a full factorial design. All the three variables were found to have a positive influence on biodiesel production. Greater biomass production was achieved by SY2 (Pichia kudriavzevii) with a value of −8.37 ± 0.067 g/L when sugarcane bagasse hydrolysate was used. Maximum lipid content of 37.99 ± 0.003% was attained by the strain G5 (Meyerozyma guilliermondii) upon using sugarcane bagasse hydrolysate in the production medium and higher lipid accumulation of 2.39 ± 0.003 g/L was attained by SY2 (Pichia kudriavzevii) upon using rice husk hydrolysate. Analysis of the kinematic properties of FAME (Fatty Acid Methyl Esters) was obtained using Biodiesel analyzer V1.1. software, and affirmed the values similar to the biodiesel standard values (EN 14214, ASTM, IS 15607). The kinematic studies used to figure out the quality of the biodiesel, revealed that FAME produced by SY2 (Pichia kudriavzevii) strain showed greater oxidation stability (37.17 h) and better kinematic viscosity (1.3084). These properties ensured that SY2 (Pichia kudriavzevii) strain was appropriate in producing exceptional quality biodiesel. Hence, the present investigation tried to prove the competency of the yeast isolates in sustainable biodiesel production by engaging agronomic wastes.

Prediction of Properties, Engine Performance and Emissions of Compression Ignition Engines Fuelled with Waste Cooking Oil Methyl Ester - A Review of Numerical Approaches

Given the challenges of renewability, affordability, and sustainability that ultra-low sulfur diesel (ULSD) fuel and first-generation biodiesel currently face, a niche clearly exists for biodiesel sourced from waste cooking oil. Exploring these potentials requires insights into a range of properties as well as performance and emission characteristics. Real-time experimental determination of fatty acid methyl ester (FAME) properties, engine performance and emissions of compression ignition (CI) engines fuelled with unblended FAME is technical, time-consuming, expensive, and requires sophisticated laboratory infrastructure, unlike numerical prediction techniques. Emerging trends and consensus indicate that utilization of numerical simulation and prediction techniques are cost-effective, less laborious, innovative, and flexible. Although FAME properties, engine performance, and emissions have been accurately predicted via various numerical techniques in the recent past, important gaps such as using numerical approaches to determine the optimal FAME mix still exist. The objective of this study was to review the numerical techniques employed in predicting FAME properties, engine performance and emissions of CI engine and investigate whether an optimal FAME candidate can be unearthed through these numerical prediction techniques. This review reports that the outcomes of these numerical predictions agree with experimental data and fall within acceptable average relative deviation but a precise approach to determining an optimal FAME candidate was not achieved. The use of numerical tools like MATLAB and computational fluid dynamics (CFD) in amalgamation with some new measurement techniques including high-speed cameras to accurately predict FAME properties, engine performance, emission characteristics and gain access to the activities in the combustion chambers, were highlighted. These high capacity modeling tools, high-speed cameras, and techniques can be used to accurately forecast an optimal FAME mix to improve engine performance, meet emission benchmarks and advanced engine research, if well harmonized.

Biodiesel potential of rendered fat from avian influenza infected poultry in a burial site

To test the feasibility of biodiesel production using rendered fat from avian influenza (AI) infected poultry in a burial site, we conducted a laboratory-scale transesterification. Each content of fatty acid methyl esters (FAME) was identified to estimate the characteristics of produced biodiesel. Analytical results of the whole FAME profile show that the rendered fat from AI carcass can be a useful source of biodiesel production. The results show 47% of total fat mass can be recovered as biodiesel. Although natural biodegradation in the burial site and soil impurities lowered the yield, the compositional properties of FAMEs confirm that the produced biodiesel presents adequate fuel characteristics, satisfying common biodiesel specifications. These findings provide evidence that our approach can be a viable option to recycle buried carcass sustainably while terminating burial sites.

Optimization of biodiesel from dried biomass of Schizochytrium limacinum using methanesulfonic acid-DMC

Novel biodiesel or fatty acid methyl ester (FAME) was produced from dried biomass of Schizochytrium limacinum with dimethyl carbonate over a time period of 30 min. The highest FAME yield could reach 84% at 85 °C with a ratio of dried biomass to dimethyl carbonate of 1:4 w/w, with extra solvent of petroleum ether, 1.5 wt. % methanesulfonic acid (based on oil weight) and an agitation speed of 150 rpm. Biomass dried with 60–120 silica gels at 38 °C for 30 min was investigated. FAME was purified using Amberlyst™ 15 dry resin. FAME was analyzed via gas chromatography-mass spectrometry with the internal standard method. The properties of FAME met the international standard ASTM D 6751-02. The results revealed that all of the reaction variables in study had positive effects. Present study indicate that FAME could be a potential alternative to diesel.

Fungal production of single cell oil using untreated copra cake and evaluation of its fuel properties for biodiesel.

This study evaluated the microbial conversion of coconut oil waste, a major agro-residue in tropical countries, into single cell oil (SCO) feedstock for biodiesel production. Copra cake was used as a low-cost renewable substrate without any prior chemical or enzymatic pretreatment for submerged growth of an oleaginous tropical mangrove fungus, Aspergillus terreus IBB M1. The SCO extracted from fermented biomass was converted into fatty acid methyl esters (FAMEs) by transesterification and evaluated on the basis of fatty acid profiles and key fuel properties for biodiesel. The fungus produced a biomass (8.2 g/l) yielding 257 mg/g copra cake SCO with ~98% FAMEs. The FAMEs were mainly composed of saturated methyl esters (61.2%) of medium-chain fatty acids (C12-C18) with methyl oleate (C18:1; 16.57%) and methyl linoleate (C18:2; 19.97%) making up the unsaturated content. A higher content of both saturated FAMEs and methyl oleate along with the absence of polyunsaturated FAMEs with ≥4 double bonds is expected to impart good fuel quality. This was evident from the predicted and experimentally determined key fuel properties of FAMEs (density, kinematic viscosity, iodine value, acid number, cetane number), which were in accordance with the international (ASTM D6751, EN 14214) and national (IS 15607) biodiesel standards, suggesting their suitability as a biodiesel fuel. The low cost, renewable nature, and easy availability of copra cake, its conversion into SCO without any thermochemical pretreatment, and pelleted fungal growth facilitating easier downstream processing by simple filtration make this process cost effective and environmentally favorable.

Optimization of Transesterification Conditions for the Production of Fatty Acid Methyl Ester (FAME) from Chinese Tallow Kernel Oil with a Nano-Scale Magnetic Catalyst

A nano-scale magnetic catalyst was used as a catalyst in preparing fatty acid methyl ester (FAME) from Chinese tallow kernel oil from Sapium sebiferum (L.) Roxb. syn. Triadica sebifera (L.) Small. FAME transesterification was analyzed using response surface methodology to find the effect of process variables on the yield of FAME and to establish prediction models. Reaction temperature and time were found to be the main factors affecting the yield of FAME with nano-scale magnetic catalyst present. Developed prediction models satisfactorily described the yield of FAME as a function of reaction temperature, time, dosage of nano-scale magnetic catalyst, and ratio of methanol to oil. The FAME mainly contained fatty acid esters of C16:0, C18:0, C18:1, C18:2, and C18:3, determined by gas chromatography. The optimal yield of FAME was 96.78%. The optimal conditions for the above yield of FAME were found to be a reaction time of 2.7 h, reaction temperature of 64°C, and 4.0% dosage of nano-scale magnetic catalyst. Thus, by using the central composite design, it is possible to determine accurate values of the transesterification parameters where maximum production of FAME occurs using the nano-scale magnetic catalyst. The fuel properties of FAME produced were compared with those of the regular diesel and found to conform to American Society for Testing and Materials (ASTM) standards.

Fatty Acid Methyl Esters as Biosolvents of Epoxy Resins: A Physicochemical Study

The C8 to C18 fatty acid methyl esters (FAME) have been compared as solvents for two epoxy resin pre-polymers, bisphenol A diglycidyl ether (DGEBA) and triglycidyl p-aminophenol ether (TGPA). It was found that the solubilization limits vary according to the ester and that methyl caprylate is the best solvent of both resins. To explain these solubility performances, physical and chemical properties of FAME were studied, such as the Hansen parameters, viscosity, binary diffusion coefficient and vaporization enthalpy. Determination of the physicochemical parameters of FAME was carried out by laboratory experimentations and by calculation from bibliographic data. The Hansen parameters of FAME and epoxy resins pre-polymers were theoretically and experimentally determined. The FAME chain length showed a long dependence on the binary diffusion parameters and kinematic viscosity, which are mass and momentum transport properties. Moreover, the vaporization enthalpy of these compounds was directly correlated with the solubilization limits.