The document discusses (liquid + liquid) equilibrium experiments involving systems relevant to the transesterification process for biodiesel production from vegetable oils. Specifically, equilibrium data was measured for systems containing vegetable oils, monoacylglycerols, diacylglycerols, ethyl esters, and ethanol. The experimental results provide information on phase behavior during transesterification and purification steps. The data was also used to evaluate thermodynamic models for predicting multicomponent phase equilibria in these systems.
The document reports on a study of extracting passion fruit seed oil using supercritical CO2. Experimental data was collected for extraction conducted at varying pressures, temperatures, and CO2 flow rates. An increase in pressure, temperature, and flow rate increased the extraction yield, with a maximum yield of 18.5% obtained. Mass transfer coefficients for passion fruit oil were determined to be 8.496 x 10-5 s-1 at specific conditions. Rheological studies observed dilatant fluid behavior in all tests. Bayesian inference was used to model mass transfer and account for parameter uncertainty.
This document discusses the optimization of supercritical carbon dioxide extraction (SCE) conditions for extracting c-linolenic acid (GLA) from Spirulina platensis. Response surface methodology (RSM) was used to optimize three extraction parameters: pressure, time, and ethanol concentration. SCE with ethanol as a co-solvent was found to significantly increase GLA yields compared to SCE alone. RSM analysis identified a pressure of 400 bars, extraction time of 1 hour, and minimum ethanol concentration of 13.7 ml per 16 g of biomass as optimal conditions for extracting 102% of the GLA content compared to conventional solvent extraction.
The present paper reports the kinetics of soybean and sunflower oils’ ethanolysis. The transesterification reaction was carried out using a molar ratio of ethanol to oil of 9:1 and 1.0 wt% of sodium ethoxide as catalyst under stirring of 400 rpm. The reactions were performed in a stirred batch reactor at three different temperatures (308.15, 323.15 and 338.15 K) over a period of 120 min. The concentration of compounds was analyzed by High-Performance Size Exclusion Chromatography (HPSEC). The kinetic model assumed that ethanolysis occurs in a sequence of three reversible steps with the production of di- and monoacylglycerols as intermediate components. Based on the modeling approach it was possible to determine the rate constants of reaction and activation energies for the transesterification process of soybean and sunflower oils. Despite the phase splitting, no mass transfer control was observed and the proposed mathematical model fitted well the experimental data.
Biodiesel production by esterification of hydrolyzed soybean oilGabriel Menchu
This document presents computational simulations of biodiesel production from hydrolyzed soybean oil in a reactive distillation column. The soybean oil is represented as a pseudocomponent mixture of its main fatty acids: linoleic acid, oleic acid, and palmitic acid. The esterification reaction of this pseudocomponent with ethanol is modeled. Sensitivity analyses are performed to determine the optimal operating conditions. Thermodynamic properties are modeled using UNIFAC for liquid phases and Antoine equations for vapor pressures.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Statistical Modeling and Optimization of Biodiesel Production from Azadiracht...IJAEMSJORNAL
This document summarizes a study that used statistical modeling and optimization to produce biodiesel from neem (Azadirachta Indica) oil using a co-solvent transesterification process. Neem oil was extracted and pretreated. A central composite design was used to experimentally vary reaction temperature, catalyst amount, reaction time, and methanol-to-oil ratio. Biodiesel yield and properties were measured. An optimized yield of 84.77% was achieved at 34°C, 1.10% catalyst, 35 minutes, and a 6:1 molar ratio. The produced biodiesel met ASTM specifications for properties like cetane number, viscosity, and flash point.
This document evaluates alternative solvents for improving oil extraction from rapeseeds compared to the commonly used n-hexane solvent. It assesses the extraction kinetics, fatty acid compositions, lipid yields, and micronutrient contents of oils extracted using ethanol, isopropanol, D-limonene, α-pinene, and p-cymene. P-cymene showed the most promise as a substitute for n-hexane with a higher lipid yield and selectivity, though micronutrient contents were relatively low. The Hansen solubility parameter model was also applied to better understand the dissolving mechanisms between alternative solvents and rapeseed oil.
An integrated approach to produce biodiesel and monoglycerides by enzymatic i...Solange Quintella
This study evaluated four commercially available lipases for their ability to catalyze two reactions: 1) the production of biodiesel from babassu oil through transesterification with ethanol, and 2) the production of monoglycerides through glycerolysis of babassu oil. Lipases from four sources were immobilized on a silica-PVA support and screened in solvent-free systems using babassu oil and the respective alcohols. Lipase PS from Burkholderia cepacia was found to be the most suitable catalyst for both reactions. Response surface methodology was then used to optimize the conditions for each reaction when catalyzed by lipase PS. The highest biodiesel yield of over 98
The document reports on a study of extracting passion fruit seed oil using supercritical CO2. Experimental data was collected for extraction conducted at varying pressures, temperatures, and CO2 flow rates. An increase in pressure, temperature, and flow rate increased the extraction yield, with a maximum yield of 18.5% obtained. Mass transfer coefficients for passion fruit oil were determined to be 8.496 x 10-5 s-1 at specific conditions. Rheological studies observed dilatant fluid behavior in all tests. Bayesian inference was used to model mass transfer and account for parameter uncertainty.
This document discusses the optimization of supercritical carbon dioxide extraction (SCE) conditions for extracting c-linolenic acid (GLA) from Spirulina platensis. Response surface methodology (RSM) was used to optimize three extraction parameters: pressure, time, and ethanol concentration. SCE with ethanol as a co-solvent was found to significantly increase GLA yields compared to SCE alone. RSM analysis identified a pressure of 400 bars, extraction time of 1 hour, and minimum ethanol concentration of 13.7 ml per 16 g of biomass as optimal conditions for extracting 102% of the GLA content compared to conventional solvent extraction.
The present paper reports the kinetics of soybean and sunflower oils’ ethanolysis. The transesterification reaction was carried out using a molar ratio of ethanol to oil of 9:1 and 1.0 wt% of sodium ethoxide as catalyst under stirring of 400 rpm. The reactions were performed in a stirred batch reactor at three different temperatures (308.15, 323.15 and 338.15 K) over a period of 120 min. The concentration of compounds was analyzed by High-Performance Size Exclusion Chromatography (HPSEC). The kinetic model assumed that ethanolysis occurs in a sequence of three reversible steps with the production of di- and monoacylglycerols as intermediate components. Based on the modeling approach it was possible to determine the rate constants of reaction and activation energies for the transesterification process of soybean and sunflower oils. Despite the phase splitting, no mass transfer control was observed and the proposed mathematical model fitted well the experimental data.
Biodiesel production by esterification of hydrolyzed soybean oilGabriel Menchu
This document presents computational simulations of biodiesel production from hydrolyzed soybean oil in a reactive distillation column. The soybean oil is represented as a pseudocomponent mixture of its main fatty acids: linoleic acid, oleic acid, and palmitic acid. The esterification reaction of this pseudocomponent with ethanol is modeled. Sensitivity analyses are performed to determine the optimal operating conditions. Thermodynamic properties are modeled using UNIFAC for liquid phases and Antoine equations for vapor pressures.
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
Statistical Modeling and Optimization of Biodiesel Production from Azadiracht...IJAEMSJORNAL
This document summarizes a study that used statistical modeling and optimization to produce biodiesel from neem (Azadirachta Indica) oil using a co-solvent transesterification process. Neem oil was extracted and pretreated. A central composite design was used to experimentally vary reaction temperature, catalyst amount, reaction time, and methanol-to-oil ratio. Biodiesel yield and properties were measured. An optimized yield of 84.77% was achieved at 34°C, 1.10% catalyst, 35 minutes, and a 6:1 molar ratio. The produced biodiesel met ASTM specifications for properties like cetane number, viscosity, and flash point.
This document evaluates alternative solvents for improving oil extraction from rapeseeds compared to the commonly used n-hexane solvent. It assesses the extraction kinetics, fatty acid compositions, lipid yields, and micronutrient contents of oils extracted using ethanol, isopropanol, D-limonene, α-pinene, and p-cymene. P-cymene showed the most promise as a substitute for n-hexane with a higher lipid yield and selectivity, though micronutrient contents were relatively low. The Hansen solubility parameter model was also applied to better understand the dissolving mechanisms between alternative solvents and rapeseed oil.
An integrated approach to produce biodiesel and monoglycerides by enzymatic i...Solange Quintella
This study evaluated four commercially available lipases for their ability to catalyze two reactions: 1) the production of biodiesel from babassu oil through transesterification with ethanol, and 2) the production of monoglycerides through glycerolysis of babassu oil. Lipases from four sources were immobilized on a silica-PVA support and screened in solvent-free systems using babassu oil and the respective alcohols. Lipase PS from Burkholderia cepacia was found to be the most suitable catalyst for both reactions. Response surface methodology was then used to optimize the conditions for each reaction when catalyzed by lipase PS. The highest biodiesel yield of over 98
Lipase-Catalyzed Biodiesel Production From Waste Activated Bleaching Earth as...ZY8
The document describes a pilot plant study of lipase-catalyzed biodiesel production from waste activated bleaching earth (ABE). Waste ABE containing vegetable oils was used as a raw material with lipase and methanol to produce fatty acid methyl esters (FAMEs), which can be used as biodiesel fuel. In a 50-liter pilot plant reactor, the process achieved 97% FAME yield within 12 hours using 1% lipase at 25°C and an agitation rate of 30 rpm. Analysis showed the biodiesel quality of a 45:55 mixture of FAME and diesel oil met European fuel standards. Emissions testing found reduced carbon monoxide and sulfur dioxide from burning the biod
TRANSESTERIFICATION OF MAHUA (MADHUCA INDICA) SEEDS OILIshaan Sanehi
Animal fat, raw, and used vegetable oils have been
explored to make bio-diesel (mono alkyl esters of long chain fatty
acid) in order to substitute the dwindling supplier of conventional
petro-diesel fuels. In the present investigation custard apple
(Annoma Squamosha), seed oil (non-edible) was Transesterified
with methanol in the presence of sodium hydroxide as catalyst.
The transesterification reaction was carried out for an
hour. The yield
of fatty acid methyl esters produced under operating conditions
was 86.4 wt%. The methyl ester produced by this reaction was
analyzed to ascertain suitability as bio diesel fuels.
APPLICATIONS OF MULTICOMPONENT ASSEMBLY PROCESSES TO THE FACILE SYNTHESES OF ...JamesSahn
Several multicomponent assembly processes have been developed for the synthesis of intermediates that may be elaborated by a variety of cyclizations to generate a diverse array of highly functionalized heterocycles from readily-available starting materials. The overall approach enables the efficient preparation of libraries of small molecules derived from fused, privileged scaffolds. Source: Heterocycles 84:2 2012 pg 1089-1112
Phase equilibrium feasibility studies of free fatty acids extraction from pal...Alexander Decker
This document summarizes a study that investigated the extraction of free fatty acids from palm oil using supercritical carbon dioxide. The study assessed the feasibility of using a thermodynamic model based on UNIFAC to predict phase equilibrium and activity coefficients for the carbon dioxide/fatty acid system. Experimental results were obtained for extract mole fraction at different pressures from 60-180 bars and temperatures of 313.15K and 353.15K. Mass transfer parameters like diffusion coefficient and solubility were also determined. The model predictions matched reasonably well with experimental data.
Multiple response optimization analysis for pretreatments of Tequila’s stilla...Roberto Bolaños
The objective of this work was study the effect of three pretreatments (alkalinization, thermical treatment, and sonication) on Tequila’s
stillages hydrolysis process in acidogenesis stage, through the following response variables: soluble chemical oxygen demand (CODs),
total sugar and volatile fatty acids profile and the hydrogen production at the time. The stillages were subject to these pretreatments
(according to a 23 factorial design); afterward they were transferred to a batch reactor at 35 C and inoculated with an anaerobic digestor
sludge. Multiple response optimization (MRO) analysis was done to find the global optimum for the response variables described above.
This optimum is able to maximize simultaneously all these variables. It was found adequate to be useful hydrolyzing the organic matter
present in Tequila’s stillages. Mathematical models were fitted to observe the estimated effects of pretreatments on each response variable,
then the MRO was applied.
2007 Elsevier Ltd. All rights reserved.
The kinetics of base catalyzed methanolysis of wasteMilan Kostic
The document summarizes a study that investigated the kinetics of base-catalyzed methanolysis of waste cooking oil at different temperatures. The reaction was found to follow pseudo-homogeneous second-order kinetics, with the reaction rate increasing at higher temperatures. A conversion of 97% was achieved within 3 minutes at 60°C, meeting biodiesel standards. The simple irreversible pseudo-second order kinetic model provided the best fit for describing the methanolysis reaction kinetics.
This document evaluates the technical and economic feasibility of producing propylene glycol from glycerol. It explores using glycerol from biodiesel production as a renewable raw material. Two hydrogen source possibilities are considered: obtaining hydrogen from an external source or producing it on-site via steam reforming of glycerol. Process simulations and equipment design are performed. It is shown that producing propylene glycol this way can be economically viable if hydrogen is obtained externally, as steam reforming hydrogen is not competitive cost-wise. However, a fully renewable process using steam reforming hydrogen is still viable depending on market conditions, though less profitable.
Ethylic esterification of free fatty acids content in macauba palm oil (acroc...AcessoMacauba
This study evaluated the use of cationic resin catalysts for the esterification of free fatty acids in macauba palm oil, which has a high acidity of 40.8% that makes it unsuitable for conventional biodiesel production. Esterification experiments using ethanol and methanol as alcohols achieved the greatest acidity reduction of 38.6% using Purolite CT275DR resin at 90°C, 20:1 alcohol:oil ratio, and 8 hours. Temperature had the most significant effect on reducing acidity. The Purolite resin performed better than Mitsubishi PK208 resin due to its higher ion exchange capacity. Cation exchange resins show potential as pretreatment catalysts for high
This document describes a one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones and thiones using 4-nitrophthalic acid as a catalyst under solvent-free conditions. Various aldehydes, 1,3-dicarbonyl compounds, and urea or thiourea reacted smoothly in good to excellent yields. The reaction conditions were optimized to use a 2 mol% catalyst loading at 90°C for 30 minutes. 4-Nitrophthalic acid proved to be an effective and inexpensive catalyst for this Biginelli reaction, providing advantages over other reported catalysts such as higher yields, simpler workup, and an environmentally friendly procedure. The products were characterized
This study developed a process for producing L-lactic acid from potato starch waste using Lactococcus lactis in a novel dialysis sac bioreactor. Fermentation in the bioreactor was compared to shake flask fermentation. The bioreactor allowed for complete starch consumption within 24 hours compared to 48 hours in shake flasks. Maximum lactic acid concentration and productivity in the bioreactor were 1.2-fold and 2.4-fold higher than shake flasks, respectively. L. lactis cells remained viable for 4 cycles in the bioreactor compared to 1 cycle in shake flasks, demonstrating improved recycling of cells.
This document describes a study that developed an efficient method for synthesizing 2-amino-3-cyano-4H-pyran derivatives using a three-component reaction. The reaction involves the cyclocondensation of aldehydes, malononitrile, and ethyl acetoacetate using ammonium hydroxide as a catalyst under infrared irradiation. The method offers high yields, short reaction times of 10 minutes, and does not require hazardous reagents or conditions. Various substituted aromatic, heteroaromatic, and aliphatic aldehydes successfully provided the desired pyran products in good to excellent yields. The reaction mechanism is proposed to occur through initial Knoevenagel condensation and subsequent Michael addition and cyclization
Effect of Temperature on Methane Production from Field-Scale Anaerobic Digest...LPE Learning Center
Full proceedings at: http://www.extension.org/72729 Anaerobic digestion is a process that results in the production of biogas that can be used a renewable source of electricity on-farm or sold to the distribution grid. Temperature is a critical parameter for anaerobic digestion since it influences both system heat requirements and methane production. Although anaerobic digestion can take place under psychrophilic (15-25°C), mesophilic (35-40°C), and thermophilic (50-60°C) conditions, temperatures of 35-37°C are typically recommended for methane production from animal manure. However, digesters require significant amount of heat energy to maintain temperatures at these levels. There is limited information about methane production from dairy digesters at temperatures less than 35°C and results in the literature are presented from laboratory-scale rather than field-scale systems.
The objective of this study was to evaluate the effect of two relatively low digestion temperatures (22 and 28°C) on methane production using replicate continuously-fed, field-scale dairy manure digesters at two organic loading rates. The results were compared with those from identical digesters operated at 35°C.
A kinetic study_on_the_esterification_of_palmiticEmiy Nicole
The document describes a kinetic study on the esterification of palmitic acid in methanol using thionyl chloride (SOCl2) as a catalyst. Key findings include:
1) SOCl2 was found to be an effective catalyst for the esterification reaction, converting palmitic acid to methyl palmitate.
2) Optimization studies determined the optimum conditions for the reaction were 0.3% weight of SOCl2 catalyst to acid, a temperature of 80°C, and a reaction time of 2 hours.
3) Kinetic measurements at different temperatures showed increased percentage conversion of reactant to product with increasing reaction time and temperature. A 100% yield was achieved at 80°C
This study examines the impact of amine and biological antioxidants on reducing NOx emissions in a diesel engine fueled with biodiesel from mango seeds. Three amine antioxidants (PPD, EDA, DPPD) and three biological antioxidants (DCM, α-T, L-asc.acid) were tested at five concentrations in B100 (100% mango biodiesel) and B20 (20% mango biodiesel, 80% diesel) fuels. Results showed the DPPD antioxidant at 0.025% concentration reduced NOx emissions the most, by 15.4% for B20 fuel and 39% for B100 fuel. DPPD also increased CO emissions
This document discusses optimizing biodiesel production from sunflower oil using response surface methodology. Response surface methodology was used to analyze how temperature, catalyst concentration, and molar ratio affect biodiesel yield. The model showed these factors significantly impact yield. Optimization found the ideal conditions were 48°C, 0.679% potassium hydroxide catalyst concentration, and 6.825:1 molar ratio, which could achieve 98.181% yield. The biodiesel produced met standards and had properties making it a suitable alternative to petrodiesel.
1) A solid-phase method for synthesizing oxazolidinones is described which uses solid-phase activation/cycloelimination (SP/ACE). This involves attaching a 1,2-diol to a polymer-bound sulfonyl chloride, reacting one alcohol with an isocyanate, then cycloelimination to form the oxazolidinone.
2) A variety of oxazolidinones were synthesized in good overall yields using this method by changing the R groups on the isocyanate and diol substrates. Enantiopure oxazolidinones were also prepared using a chiral diol derived from D-mannitol.
3) The azidomethyl groups
This document discusses different methods of asymmetric synthesis, which is a type of chemical reaction that produces unequal amounts of stereoisomeric products. It describes three main approaches: using a chiral starting material from natural sources (chiral pool synthesis), introducing chirality with an auxiliary group that is later removed (chiral auxiliaries), and using a chiral catalyst or reagent (external asymmetric induction). Examples of each method are provided. The document also summarizes several ways to separate enantiomers, such as preferential crystallization, biochemical separation, and forming diastereomers.
This PhD dissertation examines mechanistic modelling of micellization and aqueous cyclodextrin solutions with applications in biopharmaceutics. The author develops a model to predict intestinal drug absorption from an aqueous cyclodextrin solution, with a focus on the reported decreased absorption due to overdosing of cyclodextrin. Characterization of bile salt micellization is conducted using isothermal titration calorimetry. The model incorporates the multiple chemical equilibria in the small intestine, including the influence of bile salts. Application of the model correlates with in vivo rat studies and provides guidance on cyclodextrin dosing to avoid decreased absorption.
Improving Galacto-Oligosaccharide Content in the Production of Lactose-Reduce...IJERA Editor
In a lactic fermentation process with probiotic microorganisms and the simultaneous addition of -
galactosidase, the reduction of lactose content and the formation of galacto-oligosaccharides were evaluated. The
fermentation was promoted by lactic culture containing two probiotic microorganisms, Bifidobacterium animalis
and Lactobacillus acidophilus, associated with the typical microorganisms of yogurt, Lactobacillus bulgaricus
and Streptococcus thermophilus. An enzymatic preparation containing -galactosidases from Kluyveromyces
lactis and Aspergillus niger was used. A central composite rotational design (CCRD) and a total of 10 assays (22
assays plus axial points and two replicates at the central point) were conducted in order to evaluate the effects of
enzyme concentration and the time of addition of the enzyme. Based on an experimental design, empirical
models for the final lactose concentration and GOS concentration were proposed. The following conditions were
established in order to maximize GOS concentration: enzyme concentration of 0.44 g/L and enzyme addition
after 90 min from the beginning of fermentation. In these conditions a ten-fold increase in GOS concentration
and a four-fold decrease in lactose concentration were observed in comparison with fermentation without
enzyme addition.
Supercritical fluid technology in biodiesel productionAlexander Decker
This document reviews the use of supercritical fluid technology for biodiesel production as a sustainable alternative to conventional catalytic reactions. Supercritical fluid processes produce biodiesel through transesterification of vegetable oils and fats without the need for catalysts, making the process simpler and potentially more cost-effective. However, concerns remain regarding the large amounts of energy required to conduct the supercritical reactions at high temperatures and pressures. Overall, while supercritical fluid technology offers advantages over catalytic methods, challenges around energy efficiency need to be addressed for it to become a viable sustainable technology for biodiesel production.
11.supercritical fluid technology in biodiesel productionAlexander Decker
This document reviews the use of supercritical fluid technology for biodiesel production as a sustainable alternative to conventional catalytic reactions. Supercritical fluid processes produce biodiesel through transesterification of vegetable oils and fats without the need for catalysts, making the process simpler and potentially more cost-effective. However, concerns remain regarding the large amounts of energy required to conduct the supercritical reactions at high temperatures and pressures. Overall, while supercritical fluid technology offers advantages over catalytic methods, challenges around energy efficiency need to be addressed for it to become a viable sustainable technology for biodiesel production.
Lipase-Catalyzed Biodiesel Production From Waste Activated Bleaching Earth as...ZY8
The document describes a pilot plant study of lipase-catalyzed biodiesel production from waste activated bleaching earth (ABE). Waste ABE containing vegetable oils was used as a raw material with lipase and methanol to produce fatty acid methyl esters (FAMEs), which can be used as biodiesel fuel. In a 50-liter pilot plant reactor, the process achieved 97% FAME yield within 12 hours using 1% lipase at 25°C and an agitation rate of 30 rpm. Analysis showed the biodiesel quality of a 45:55 mixture of FAME and diesel oil met European fuel standards. Emissions testing found reduced carbon monoxide and sulfur dioxide from burning the biod
TRANSESTERIFICATION OF MAHUA (MADHUCA INDICA) SEEDS OILIshaan Sanehi
Animal fat, raw, and used vegetable oils have been
explored to make bio-diesel (mono alkyl esters of long chain fatty
acid) in order to substitute the dwindling supplier of conventional
petro-diesel fuels. In the present investigation custard apple
(Annoma Squamosha), seed oil (non-edible) was Transesterified
with methanol in the presence of sodium hydroxide as catalyst.
The transesterification reaction was carried out for an
hour. The yield
of fatty acid methyl esters produced under operating conditions
was 86.4 wt%. The methyl ester produced by this reaction was
analyzed to ascertain suitability as bio diesel fuels.
APPLICATIONS OF MULTICOMPONENT ASSEMBLY PROCESSES TO THE FACILE SYNTHESES OF ...JamesSahn
Several multicomponent assembly processes have been developed for the synthesis of intermediates that may be elaborated by a variety of cyclizations to generate a diverse array of highly functionalized heterocycles from readily-available starting materials. The overall approach enables the efficient preparation of libraries of small molecules derived from fused, privileged scaffolds. Source: Heterocycles 84:2 2012 pg 1089-1112
Phase equilibrium feasibility studies of free fatty acids extraction from pal...Alexander Decker
This document summarizes a study that investigated the extraction of free fatty acids from palm oil using supercritical carbon dioxide. The study assessed the feasibility of using a thermodynamic model based on UNIFAC to predict phase equilibrium and activity coefficients for the carbon dioxide/fatty acid system. Experimental results were obtained for extract mole fraction at different pressures from 60-180 bars and temperatures of 313.15K and 353.15K. Mass transfer parameters like diffusion coefficient and solubility were also determined. The model predictions matched reasonably well with experimental data.
Multiple response optimization analysis for pretreatments of Tequila’s stilla...Roberto Bolaños
The objective of this work was study the effect of three pretreatments (alkalinization, thermical treatment, and sonication) on Tequila’s
stillages hydrolysis process in acidogenesis stage, through the following response variables: soluble chemical oxygen demand (CODs),
total sugar and volatile fatty acids profile and the hydrogen production at the time. The stillages were subject to these pretreatments
(according to a 23 factorial design); afterward they were transferred to a batch reactor at 35 C and inoculated with an anaerobic digestor
sludge. Multiple response optimization (MRO) analysis was done to find the global optimum for the response variables described above.
This optimum is able to maximize simultaneously all these variables. It was found adequate to be useful hydrolyzing the organic matter
present in Tequila’s stillages. Mathematical models were fitted to observe the estimated effects of pretreatments on each response variable,
then the MRO was applied.
2007 Elsevier Ltd. All rights reserved.
The kinetics of base catalyzed methanolysis of wasteMilan Kostic
The document summarizes a study that investigated the kinetics of base-catalyzed methanolysis of waste cooking oil at different temperatures. The reaction was found to follow pseudo-homogeneous second-order kinetics, with the reaction rate increasing at higher temperatures. A conversion of 97% was achieved within 3 minutes at 60°C, meeting biodiesel standards. The simple irreversible pseudo-second order kinetic model provided the best fit for describing the methanolysis reaction kinetics.
This document evaluates the technical and economic feasibility of producing propylene glycol from glycerol. It explores using glycerol from biodiesel production as a renewable raw material. Two hydrogen source possibilities are considered: obtaining hydrogen from an external source or producing it on-site via steam reforming of glycerol. Process simulations and equipment design are performed. It is shown that producing propylene glycol this way can be economically viable if hydrogen is obtained externally, as steam reforming hydrogen is not competitive cost-wise. However, a fully renewable process using steam reforming hydrogen is still viable depending on market conditions, though less profitable.
Ethylic esterification of free fatty acids content in macauba palm oil (acroc...AcessoMacauba
This study evaluated the use of cationic resin catalysts for the esterification of free fatty acids in macauba palm oil, which has a high acidity of 40.8% that makes it unsuitable for conventional biodiesel production. Esterification experiments using ethanol and methanol as alcohols achieved the greatest acidity reduction of 38.6% using Purolite CT275DR resin at 90°C, 20:1 alcohol:oil ratio, and 8 hours. Temperature had the most significant effect on reducing acidity. The Purolite resin performed better than Mitsubishi PK208 resin due to its higher ion exchange capacity. Cation exchange resins show potential as pretreatment catalysts for high
This document describes a one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones and thiones using 4-nitrophthalic acid as a catalyst under solvent-free conditions. Various aldehydes, 1,3-dicarbonyl compounds, and urea or thiourea reacted smoothly in good to excellent yields. The reaction conditions were optimized to use a 2 mol% catalyst loading at 90°C for 30 minutes. 4-Nitrophthalic acid proved to be an effective and inexpensive catalyst for this Biginelli reaction, providing advantages over other reported catalysts such as higher yields, simpler workup, and an environmentally friendly procedure. The products were characterized
This study developed a process for producing L-lactic acid from potato starch waste using Lactococcus lactis in a novel dialysis sac bioreactor. Fermentation in the bioreactor was compared to shake flask fermentation. The bioreactor allowed for complete starch consumption within 24 hours compared to 48 hours in shake flasks. Maximum lactic acid concentration and productivity in the bioreactor were 1.2-fold and 2.4-fold higher than shake flasks, respectively. L. lactis cells remained viable for 4 cycles in the bioreactor compared to 1 cycle in shake flasks, demonstrating improved recycling of cells.
This document describes a study that developed an efficient method for synthesizing 2-amino-3-cyano-4H-pyran derivatives using a three-component reaction. The reaction involves the cyclocondensation of aldehydes, malononitrile, and ethyl acetoacetate using ammonium hydroxide as a catalyst under infrared irradiation. The method offers high yields, short reaction times of 10 minutes, and does not require hazardous reagents or conditions. Various substituted aromatic, heteroaromatic, and aliphatic aldehydes successfully provided the desired pyran products in good to excellent yields. The reaction mechanism is proposed to occur through initial Knoevenagel condensation and subsequent Michael addition and cyclization
Effect of Temperature on Methane Production from Field-Scale Anaerobic Digest...LPE Learning Center
Full proceedings at: http://www.extension.org/72729 Anaerobic digestion is a process that results in the production of biogas that can be used a renewable source of electricity on-farm or sold to the distribution grid. Temperature is a critical parameter for anaerobic digestion since it influences both system heat requirements and methane production. Although anaerobic digestion can take place under psychrophilic (15-25°C), mesophilic (35-40°C), and thermophilic (50-60°C) conditions, temperatures of 35-37°C are typically recommended for methane production from animal manure. However, digesters require significant amount of heat energy to maintain temperatures at these levels. There is limited information about methane production from dairy digesters at temperatures less than 35°C and results in the literature are presented from laboratory-scale rather than field-scale systems.
The objective of this study was to evaluate the effect of two relatively low digestion temperatures (22 and 28°C) on methane production using replicate continuously-fed, field-scale dairy manure digesters at two organic loading rates. The results were compared with those from identical digesters operated at 35°C.
A kinetic study_on_the_esterification_of_palmiticEmiy Nicole
The document describes a kinetic study on the esterification of palmitic acid in methanol using thionyl chloride (SOCl2) as a catalyst. Key findings include:
1) SOCl2 was found to be an effective catalyst for the esterification reaction, converting palmitic acid to methyl palmitate.
2) Optimization studies determined the optimum conditions for the reaction were 0.3% weight of SOCl2 catalyst to acid, a temperature of 80°C, and a reaction time of 2 hours.
3) Kinetic measurements at different temperatures showed increased percentage conversion of reactant to product with increasing reaction time and temperature. A 100% yield was achieved at 80°C
This study examines the impact of amine and biological antioxidants on reducing NOx emissions in a diesel engine fueled with biodiesel from mango seeds. Three amine antioxidants (PPD, EDA, DPPD) and three biological antioxidants (DCM, α-T, L-asc.acid) were tested at five concentrations in B100 (100% mango biodiesel) and B20 (20% mango biodiesel, 80% diesel) fuels. Results showed the DPPD antioxidant at 0.025% concentration reduced NOx emissions the most, by 15.4% for B20 fuel and 39% for B100 fuel. DPPD also increased CO emissions
This document discusses optimizing biodiesel production from sunflower oil using response surface methodology. Response surface methodology was used to analyze how temperature, catalyst concentration, and molar ratio affect biodiesel yield. The model showed these factors significantly impact yield. Optimization found the ideal conditions were 48°C, 0.679% potassium hydroxide catalyst concentration, and 6.825:1 molar ratio, which could achieve 98.181% yield. The biodiesel produced met standards and had properties making it a suitable alternative to petrodiesel.
1) A solid-phase method for synthesizing oxazolidinones is described which uses solid-phase activation/cycloelimination (SP/ACE). This involves attaching a 1,2-diol to a polymer-bound sulfonyl chloride, reacting one alcohol with an isocyanate, then cycloelimination to form the oxazolidinone.
2) A variety of oxazolidinones were synthesized in good overall yields using this method by changing the R groups on the isocyanate and diol substrates. Enantiopure oxazolidinones were also prepared using a chiral diol derived from D-mannitol.
3) The azidomethyl groups
This document discusses different methods of asymmetric synthesis, which is a type of chemical reaction that produces unequal amounts of stereoisomeric products. It describes three main approaches: using a chiral starting material from natural sources (chiral pool synthesis), introducing chirality with an auxiliary group that is later removed (chiral auxiliaries), and using a chiral catalyst or reagent (external asymmetric induction). Examples of each method are provided. The document also summarizes several ways to separate enantiomers, such as preferential crystallization, biochemical separation, and forming diastereomers.
This PhD dissertation examines mechanistic modelling of micellization and aqueous cyclodextrin solutions with applications in biopharmaceutics. The author develops a model to predict intestinal drug absorption from an aqueous cyclodextrin solution, with a focus on the reported decreased absorption due to overdosing of cyclodextrin. Characterization of bile salt micellization is conducted using isothermal titration calorimetry. The model incorporates the multiple chemical equilibria in the small intestine, including the influence of bile salts. Application of the model correlates with in vivo rat studies and provides guidance on cyclodextrin dosing to avoid decreased absorption.
Improving Galacto-Oligosaccharide Content in the Production of Lactose-Reduce...IJERA Editor
In a lactic fermentation process with probiotic microorganisms and the simultaneous addition of -
galactosidase, the reduction of lactose content and the formation of galacto-oligosaccharides were evaluated. The
fermentation was promoted by lactic culture containing two probiotic microorganisms, Bifidobacterium animalis
and Lactobacillus acidophilus, associated with the typical microorganisms of yogurt, Lactobacillus bulgaricus
and Streptococcus thermophilus. An enzymatic preparation containing -galactosidases from Kluyveromyces
lactis and Aspergillus niger was used. A central composite rotational design (CCRD) and a total of 10 assays (22
assays plus axial points and two replicates at the central point) were conducted in order to evaluate the effects of
enzyme concentration and the time of addition of the enzyme. Based on an experimental design, empirical
models for the final lactose concentration and GOS concentration were proposed. The following conditions were
established in order to maximize GOS concentration: enzyme concentration of 0.44 g/L and enzyme addition
after 90 min from the beginning of fermentation. In these conditions a ten-fold increase in GOS concentration
and a four-fold decrease in lactose concentration were observed in comparison with fermentation without
enzyme addition.
Supercritical fluid technology in biodiesel productionAlexander Decker
This document reviews the use of supercritical fluid technology for biodiesel production as a sustainable alternative to conventional catalytic reactions. Supercritical fluid processes produce biodiesel through transesterification of vegetable oils and fats without the need for catalysts, making the process simpler and potentially more cost-effective. However, concerns remain regarding the large amounts of energy required to conduct the supercritical reactions at high temperatures and pressures. Overall, while supercritical fluid technology offers advantages over catalytic methods, challenges around energy efficiency need to be addressed for it to become a viable sustainable technology for biodiesel production.
11.supercritical fluid technology in biodiesel productionAlexander Decker
This document reviews the use of supercritical fluid technology for biodiesel production as a sustainable alternative to conventional catalytic reactions. Supercritical fluid processes produce biodiesel through transesterification of vegetable oils and fats without the need for catalysts, making the process simpler and potentially more cost-effective. However, concerns remain regarding the large amounts of energy required to conduct the supercritical reactions at high temperatures and pressures. Overall, while supercritical fluid technology offers advantages over catalytic methods, challenges around energy efficiency need to be addressed for it to become a viable sustainable technology for biodiesel production.
This document discusses an experimental study of liquid-liquid equilibrium (LLE) in pseudoternary systems containing glycerol, ethanol, and fatty acid ethyl esters from crambe oil at temperatures of 298.2 K, 318.2 K, and 338.2 K. LLE data were obtained for these systems and used to adjust parameters for the NRTL thermodynamic model. Two sets of UNIFAC binary interaction parameters were also tested to predict the LLE. Ethanol showed a greater affinity for the glycerol-rich phase. Glycerol and fatty acid ethyl esters exhibited very low miscibility. The NRTL model predictions had average mass fraction deviations below 0.82% from
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Triacylglycerols produced by plants are one of the most energy-rich and abundant forms of reduced carbon available from nature. Given their chemical similarities, plant oils represent a logical substitute for conventional diesel, a non-renewable energy source. However, as plant oils are too viscous for use in modern diesel engines, they are converted to fatty acid esters. Apart from seed oil vegetative tissue is potential source as bio mass for biofuel production, taking 15 tonnes per hectare as an average dry matter yield for a perennial grass, an oil content of 20– 25% by weight will produce about 3400 l of biodiesel (Heaton et al., 2004). There is growing interest in engineering green biomass to expand the production of plant oils as feed and biofuels. Here, we show that PHOSPHOLIPID: DIACYLGLYCEROL ACYLTRANSFERASE1 (PDAT1) is a critical enzyme involved in triacylglycerol (TAG) synthesis in leaves. Overexpression of PDAT1 increases leaf TAG accumulation, leading to oil droplet overexpansion through fusion. Ectopic expression of oleosin promotes the clustering of small oil droplets. Coexpression of PDAT1 with oleosin boosts leaf TAG content by up to 6.4% of the dry weight without affecting membrane lipid composition and plant growth. PDAT1 overexpression stimulates fatty acid synthesis (FAS) and increases fatty acid flux toward the prokaryotic glycerolipid pathway (Julian at al..2013). First, an Arabidopsis thaliana gene diacylglycerol acyltransferase (DGAT) coding for a key enzyme in triacylglycerol (TAG) biosynthesis, was expressed in tobacco under the control of a strong ribulose-biphosphate carboxylase small subunit promoter. This modification led to up to a 20-fold increase in TAG accumulation in tobacco leaves and translated into an overall of about a twofold increase in extracted fatty acids (FA) up to 5.8% of dry biomass in Nicotiana tabacum cv Wisconsin, and up to 6% in high-sugar tobacco variety NC-55 ( Andrianovet al 2010). Therefore Biotechnology has important and perhaps critical part to play in large-scale development of Biodiesel.
Optimization of Sunflower Methyl Ester and its Tribological StudiesIJRES Journal
The mineral oil lubricants that are being used these days are not sure of lasting for a long time. There are chances of them being depleted in a short span of years. As a replacement for the mineral oils, various vegetable oils are taken up for research purpose in order to use them as an alternate for the present mineral lubrication. Bio lubricant is produced by transesterification of a triglyceride with methanol in the presence of catalyst to produce fatty acid methyl esters (FAME) and glycerol. The main parameters affecting the transesterification reactions are molar ratio, catalyst type and amount, reaction time, temperature and stirrer speed. In this work, the producrion of sunflower methyl ester (SFME) can be optimized by using Taguchi technique and the properties of a lubricant like viscosity, flash point and fire point is found out, also four ball wear test proved that the SFME+crude SFO proportions produced less wear scar than conventional 2T oil which revealed that the prepared bio lubricant can be used in a commercial vehicle.
Comparative Ethanol Productivities of Two Different Recombinant Fermenting St...IJERA Editor
This document summarizes a study that compared the ethanol productivity of two recombinant fermenting strains - Zymomonas mobilis 8b and Saccharomyces cerevisiae DA2416 - on pretreated source-separated organic waste. Source-separated organic waste was pretreated using thermal screw press and cellulose-organic-solvent lignocellulose fractionation. Enzymatic hydrolysis using Accellerase 1500 achieved 90% sugar yield. Both strains achieved similar ethanol yields of 0.48g/g based on sugar consumed, though S. cerevisiae DA2416 performed slightly better with a process yield of 0.49g/g. This study provides insights into using source-separated organic waste for ethanol production
Biooil extraction of Jatropha curcas with ionic liquid co-solventMelisa Edwards
This document summarizes a study that tracked the fate of protein from Jatropha curcas biomass through an extraction process using an ionic liquid co-solvent system. The majority of protein (86%) remained with the biomass after extraction, while a small amount was lost to the co-solvent (12%) and methanol washes (2%). A significant portion of the ionic liquid also remained with the treated biomass and required additional methanol washes to recover. The system showed a net-positive energy balance but additional costs of solvent recovery need to be addressed for commercial viability.
The document describes the production, purification, and characterization of lipase from Microbacterium sp. and its application in biodiesel production. Key findings include:
1) Microbacterium sp. was identified as a lipase producing bacterium through isolation, screening, and 16S rDNA sequencing.
2) Lipase from Microbacterium sp. was purified using ammonium sulfate precipitation and gel filtration chromatography, resulting in a 2.1-fold purification.
3) The lipase showed maximum activity at pH 8.5 and 50°C and was stable in organic solvents and detergents.
4) Immobilized lipase retained over 95% activity after 10
A Study On The Performance And Combustion Of A Diesel Engine Fuelled With B...theijes
This paper highlights the performance and combustion of a single cylinder four stroke diesel engine operated on blends of biodiesel produced from waste cooking oil. An additive Diethyl ether (DEE) has been added in three different proportions to B20 blended fuel to study the effect of additive on the performance and combustion of the diesel engine. Our results conclude that the break thermal efficiencies of the diesel engine show an increasing trend with both blended fuels and additive mixed blended fuels, slightly higher than the case of pure diesel fuel.
This document describes a process to extract free fatty acids from wet biomass of the microalga Nannochloropsis gaditana for biodiesel production. The process involves five steps: 1) direct saponification of the wet biomass using KOH-ethanol solution to extract fatty acids as potassium salts, 2) separation of unsaponifiable lipids from the solution with hexane, 3) acidification and extraction of purified free fatty acids with hexane, 4) esterification of the free fatty acids into biodiesel using methanol catalyzed by sulfuric acid, and 5) purification of the biodiesel by washing with hot water and adsorption with bentonite. The final biodiesel purity was
Microbial catalysis of syngas fermentation into biofuels precursors - An expe...Pratap Jung Rai
Search for environment-friendly sustainable energy sources is of global interest due to continuous depletion of fossil fuels resources and excessive carbon dioxide emissions. Syngas fermentation is one of the promising sustainable alternative for liquid biofuel and chemical production from energy content wastes/byproducts. This study mainly focuses on acetic acid and ethanol production via fermentation, using hydrogen and carbon dioxide as substrates to mimic syngas. A laboratory scale, batch fermentation was performed at different headspace pressure ranged from 0.29 to 1.51 bar, 1200 rpm stirrer speed, and 22±1.4ºC.
Formation of acetic acid and ethanol were found significant. The maximum acetic acid concentration 68 mmol/L was obtained at 1176 hours and 1.12 bar headspace pressure. However, maximum ethanol concentration of 15 pA*s was found at 1297 hours and 1.51 bar headspace pressure. Ethanol consumption was observed during first 553 hours. Maximum H2 consumption rate was 0.153 mmol/h•gVS during 478-527 hours at 1.12 bar headspace pressure, which was 51 times higher than that obtained during first 71 hours at 0.29 bar headspace pressure (0.003 mmol/h• gVS). The total consumed hydrogen gas measure as COD (CODHydrogen) was equivalent to the increase in bulk liquid COD, 11.02 gCOD and 11.44 gCOD; in which 68% of CODHydrogen was converted to acetic acid (7.44 gCOD). A significant influence of headspace pressure and dissolved hydrogen concentration were observed on the volumetric mass (H2) transfer coefficient (kLa) and the solubility of hydrogen in the inoculum (CH). The maximum kLa and CH of 0.082 h-1 (R2 = 0.995) and 1.2 10-3 mol/L were found at 1.12 bar headspace pressure and 89 mmol/L dissolved hydrogen concentration, respectively. The calculated biomass yields ranged from 0.001-0.066 and 0.001-0.059 gVSS/gCOD, for acetic acid and ethanol formation, respectively, when the assumption of free energy efficiency use in growth was changed from 0.1 to 1.
Acetic acid and ethanol were dominant final product whereas other organic acids were almost constant and insignificant throughout the experiment. This implies that the microbial fermentation of hydrogen and carbon dioxide at headspace pressure ranged from 0.29-1.51 bar, 1200 rpm stirrer speed, and 22±1.4ºC, can be performed with digested food waste sludge for efficient acetic acid and ethanol production.
Integration of sewage sludge digestion with advanced biofuel synthesiszhenhua82
The document describes integrating anaerobic digestion of sewage sludge with advanced biofuel production. Sewage sludge was treated with anaerobic digestion under two conditions: 1) low pH control and 2) chemical inhibition of methanogens. Both treatments resulted in accumulation of acetic acid. Acetic acid from digestion was then used as a carbon source for a fungus (Mortierella isabellina) and engineered Escherichia coli to produce fatty acids. The engineered E. coli strain had higher fatty acid yield and produced both medium and long chain fatty acids, while the fungus mainly produced long chain fatty acids. The study demonstrated a potential process to combine anaerobic digestion with microbial cultivation to simultaneously treat sewage
Process Design and Economics for Conversion of Algal Biomass to HydrocarbonsBiorefineryEPC™
Process Design and Economics for Conversion of Algal Biomass to Hydrocarbons
DISCLAIMER:
YOU AGREE TO INDEMNIFY BioRefineryEPC™ , AND ITS AFFILIATES, OFFICERS, AGENTS, AND EMPLOYEES AGAINST ANY CLAIM OR DEMAND, INCLUDING REASONABLE ATTORNEYS' FEES, RELATED TO YOUR USE, RELIANCE, OR ADOPTION OF THE DATA FOR ANY PURPOSE WHATSOEVER. THE DATA ARE PROVIDED BY BioRefineryEPC™ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY DISCLAIMED. IN NO EVENT SHALL BioRefineryEPC™ BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER, INCLUDING BUT NOT LIMITED TO CLAIMS ASSOCIATED WITH THE LOSS OF DATA OR PROFITS, WHICH MAY RESULT FROM ANY ACTION IN CONTRACT, NEGLIGENCE OR OTHER TORTIOUS CLAIM THAT ARISES OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THE DATA.
Depleting nature of nonrenewable energy sources and continuous environmental tribulations make the mankind to think differently regarding alternative renewable energy sources. In this regard, present research investigation contributes biodiesel from canola oil deodorizer distillate (CODD) using Lipase AY Amano 30 (Candida rugosa) and Novozyme 40013 (Candida antarctica) in the presence of methanol. Initially the neutral glycerides present in CODD were hydrolysed using lipase Amano AY 30 in the presence of water. The hydrolysed CODD was then esterified with methanol using non-specific immobilized enzyme NS 40013 for the production of biodiesel. The characteristics of final product were compared with diesel fuel and it showed good results. This bioprocess technology using biohydrolysis and bioesterification is a novel technology for biodiesel production from cheap raw materials like CODD.
International Journal of Engineering Inventions (IJEI) provides a multidisciplinary passage for researchers, managers, professionals, practitioners and students around the globe to publish high quality, peer-reviewed articles on all theoretical and empirical aspects of Engineering and Science.
Performance, Combustion and Emission Evaluation of Fish and Corn Oil as subst...IDES Editor
The indiscriminate usage of fossil fuels in many
countries has led to an increased interest in the search for
suitable alternative fuels. Methyl Esters of Vegetable oils and
Animal fats are found to be good alternative, renewable and
environmental friendly fuels for C.I. engines.
This paper presents the results of investigation carried
out in studying the properties and behavior of methyl esters
of corn seed oil, fish oil and its blends with diesel fuel in a C
I Engine. Engine tests have been carried out to determine the
performance, emission and combustion characteristics of the
above mentioned fuels.
The tests have been carried out in a 4-stroke,
computerized, single cylinder, constant speed, direct injection
diesel engine at different loads. The loads were varied from
0% to 100% of the maximum load in steps of 25%. The Methyl
Ester blends of 10%, 20% and 30% by volume with diesel were
used. The engine test parameters were recorded with the help
of engine analysis software and were studied with the help of
graphs.
The results showed that the properties of the above mentioned
oils are comparable with conventional diesel. The 20% blend
performed well in running a diesel engine at a constant speed
of 1500 rpm. It substantially reduced the emissions with
acceptable efficiency. Hence the oils can be used as suitable
additives for diesel in compression ignition engine.
The document discusses biodiesel production through transesterification of triglycerides with alcohol. Response surface methodology is used to analyze how temperature, catalyst concentration, and molar ratio of methanol to oil affect biodiesel yield. Biodiesel is defined as mono-alkyl esters derived from vegetable oils or animal fats, and has advantages over fossil fuels like being non-toxic and biodegradable. Vegetable oils are commonly used as feedstock, with sunflower, soybean, and rapeseed oils being potential alternative fuels. Transesterification is used to reduce vegetable oil viscosity for use in diesel engines. The document examines optimizing transesterification of sunflower oil through varying conditions like temperature,
Biodiesel is produced by transesterification of
triglycérides present in animal fat or vegetable oils, by
displacing glycerine with a low molar mass atcobol. This
resulting ester mixture has physico-chemical properties
similar to those of petroleum diesel.
This paper reviews the synthetic paths that lead to
biodiesel by means of the catalytic transesterification of
vegetable oils. Although methyl esters are at present the only
ones produced at industrial scale, the use of ethanol, which
can also be obtained from renewable resources, has been
considered, since it would generate a cleaner and more
biocompatible fuel.
Similar to (Liquid liquid) equilibrium of systems involved in the stepwise ethanolysis of vegetable oils (20)
The fmincon function finds the minimum of a constrained nonlinear multivariable function subject to bounds and linear and nonlinear constraints. It uses either a medium-scale or large-scale algorithm depending on whether the gradient of the objective function is provided. The user defines the objective function fun and optional nonlinear constraints nonlcon, both of which can return gradient and Hessian information. Fmincon returns the optimized values, objective function value, exit condition, and additional output details.
The document contains critical data for various compounds including their molecular weights, freezing points, boiling points, critical temperatures, pressures, volumes, compressibility factors, and acentric factors. The data is presented in a table with 27 compounds listed along with their properties. This table provides physical property data for analysis of these compounds and calculations involving their critical points and states.
Influence of temperature on the liquid liquid equilibria of methanol benzene ...Josemar Pereira da Silva
This document summarizes a study on the liquid-liquid equilibrium of the ternary system composed of methanol, benzene, and hexane at different temperatures. Experimental data on the compositions of the coexisting liquid phases are reported at 278.15 K, 283.15 K, and 293.15 K. The data show that increasing the temperature decreases the miscibility gap between the methanol-rich and hexane-rich phases. Models like UNIQUAC and NRTL are able to correlate the experimental equilibrium data reasonably well at the different temperatures, while UNIFAC predicts a larger immiscibility region than observed.
Liquid liquid equilibrium for the ternary system of isopropyl acetate 2 propa...Josemar Pereira da Silva
The document presents experimental data on liquid-liquid equilibrium for the ternary system of isopropyl acetate, 2-propanol, and glycerol at temperatures of 298.15 K, 308.15 K, and 318.15 K under atmospheric pressure. Triangular phase diagrams were obtained at each temperature showing the two-phase region. Distribution coefficients and selectivity parameters were calculated to evaluate glycerol's capacity as an extractive solvent. The NRTL and UNIQUAC models were applied to correlate the experimental data with low deviations.
Liquid liquid equilibrium data for n hexane ethylacetate acetonitrile ternay ...Josemar Pereira da Silva
This document presents experimental liquideliquid equilibrium (LLE) data for the ternary system of n-hexane, ethyl acetate, and acetonitrile measured at 298.15 K, 308.15 K, and 318.15 K. The NRTL and UNIQUAC models were used to correlate the LLE data. Distribution coefficients and separation factors were also calculated from the LLE data, showing that acetonitrile could be used to extract ethyl acetate from n-hexane.
Liquid liquid equilibria data for ethylbenzene or p xylene with alkane and 1 ...Josemar Pereira da Silva
This document presents experimental liquid-liquid equilibrium data for ternary mixtures of 1-butylpyridinium nitrate ionic liquid, various alkanes (heptane, octane, decane), and either ethylbenzene or p-xylene at 298.15 K and 89 kPa. The data includes mole fraction measurements of each phase and calculations of distribution ratios and separation factors. Six different ternary systems were studied and the results suggest p-xylene can be separated more easily from alkanes than ethylbenzene.
Influence of temperature on the liquid liquid equilibria of methanol benzene ...Josemar Pereira da Silva
This document summarizes a study on the liquid-liquid equilibria of the ternary system composed of methanol, benzene, and hexane at temperatures of 278.15 K, 283.15 K, and 293.15 K. Equilibrium data including component mass fractions in each phase are reported for the three temperatures. The data are compared to literature data and correlated using various models including Othmer and Tobias, NRTL, and UNIFAC. The results show that temperature influences the liquid-liquid equilibrium behavior of the system.
Isobaric vapor liquid equilibrium for binary mixtures of 3 methyl 1 butanol 3...Josemar Pereira da Silva
This document presents experimental vapor-liquid equilibrium data for the binary mixtures of 3-methyl-1-butanol + 3-methyl-1-butyl ethanoate and 1-pentanol + pentyl ethanoate at 101.3 kPa. Vapor pressure measurements were made for the pure components using a Swiestoslawski apparatus. Vapor-liquid equilibrium data were obtained using an equilibrium still. Activity coefficients were calculated and correlated using thermodynamic models like Wilson, NRTL, and UNIQUAC. The mixtures were found to not form azeotropes.
Investigation on thermodynamics in separation for ethylene glycol neopentyl g...Josemar Pereira da Silva
The document investigates azeotropic distillation for separating an ethylene glycol (EG) and neopentyl glycol (NPG) system. Vapor-liquid equilibrium data was measured for the EG-NPG and NPG-para-xylene systems under atmospheric pressure. The data was found to be thermodynamically consistent and well-correlated by models like NRTL and UNIQUAC. An azeotropic distillation process was designed using para-xylene as an entrainer that can produce EG and NPG at 99.9% purity with minimal cost.
This document presents a new correlation for predicting the thermal conductivity of liquids based on their molar polarization. The correlation relates two parameters (A and b) from an existing thermal conductivity equation to molar polarization. Molar polarization takes into account molecular structure, polarity, and temperature effects. Experimental thermal conductivity data for various substances was used to develop a correlation between the parameters and molar polarization. The new correlation was found to predict thermal conductivity with average errors less than 5% for most substances tested, outperforming some existing methods.
This document presents a new two-parameter model for predicting the thermal conductivity of liquids. The model is derived based on theories of molecular dynamics, liquid free volume, and the authors' previous model for estimating heat of vaporization. Thermal conductivity data for 68 liquids over a wide range of temperatures are fitted using the model and compared to other existing models, showing good agreement. Key parameters A and B are determined for different liquids to allow calculation of thermal conductivity at any temperature within the studied ranges.
Este documento apresenta um estudo sobre escoamento bifásico líquido-gás em tubulações
horizontais utilizando a correlação de Lockhart & Martinelli e simulações computacionais. Foram
analisados os regimes borbulhado e estratificado para misturas água-ar a 25°C em tubo de 1 polegada.
As simulações computacionais foram realizadas no código ANSYS CFX e comparadas às previsões da
correlação de Lockhart & Martinelli, encontrando-se desvios de até 50% entre os métodos.
Este documento apresenta a tese de doutorado de Cristiano Bigonha Tibiriçá sobre o estudo experimental e teórico da transferência de calor e do fluxo crítico durante a ebulição convectiva em microcanais. O trabalho analisa dados obtidos em bancadas experimentais construídas para este fim e desenvolve modelos considerando os padrões de escoamento observados em microcanais.
On criteria for occurence of azeotropes in isothermal and isobraric binary sy...Josemar Pereira da Silva
The document discusses criteria for predicting the occurrence of azeotropes in binary systems under isothermal and isobaric conditions.
For isothermal systems, the criteria are expressed in terms of the activity coefficients at infinite dilution (γ∞). For a positive azeotrope, γ∞ of the less volatile component must be greater than or equal to the ratio of the saturation vapor pressures. For a negative azeotrope, γ∞ of the more volatile component must be less than or equal to the inverse of the ratio.
For isobaric systems, the criteria involve γ∞ evaluated at the boiling points. For a minimum-boiling azeotrope
This document is a doctoral thesis submitted by Efstathios Skouras-Iliopoulos for the degree of Doctor of Engineering at the Norwegian University of Science and Technology. The thesis focuses on feasibility and operation aspects of heterogeneous azeotropic (heteroazeotropic) distillation in batch distillation columns. Both conventional batch columns (rectifiers) and novel multivessel column configurations are considered for separating azeotropic mixtures. Dynamic simulations are used to analyze time requirements and separation performance of different column configurations for various mixture types. The thesis aims to provide a deeper understanding of heteroazeotropic batch distillation and develop guidelines for assessing feasibility and practical operation of such processes.
This document presents a new two-parameter model for predicting the thermal conductivity of liquids. The model is derived based on theories of molecular dynamics, liquid free volume, and the authors' previous model for estimating heat of vaporization. Thermal conductivity data for 68 liquids over a wide range of temperatures are fitted using the model and compared to other existing models, showing good agreement. Key parameters A and B are determined for different liquids to allow calculation of thermal conductivity based on fundamental physical property data.
Production of-n-propyl-acetate-by-reactive-distillation-experimental-and-theo...Josemar Pereira da Silva
This document summarizes the first steps in developing a catalytic reactive distillation process for producing n-propyl acetate. Kinetic experiments were conducted to determine the reaction rates for homogeneous and heterogeneous catalysis. Pilot plant experiments were also performed using a homogeneous strong acid catalyst in a packed column with a top-column decanter. Simulation results matched experimental data well when accounting for non-ideal thermodynamics. Several process configurations were identified that could dramatically increase alcohol conversion and n-propyl acetate purity by adding a stripping section. The best startup strategy was determined to involve an initial charging of the two-phase top product to achieve steady-state conditions most quickly.
This document summarizes the topological structure of ternary residue curve maps, which describe the dynamics of ternary distillation processes. It introduces differential equations that model ternary distillation and place a meaningful structure on ternary phase diagrams. By recognizing this structure is subject to the Poincaré-Hopf index theorem, the authors obtained a topological relationship between azeotropes and pure components in ternary mixtures. This relationship provides useful information about ternary mixture distillation behavior and predicts situations where ternary azeotropes cannot occur.
The document describes combining the UNIWAALS equation of state with an algorithm for calculating simultaneous chemical and phase equilibria (CPE). This allows CPE calculations for reactive systems containing gases, polar compounds, or both over a broad range of temperatures and pressures using a single thermodynamic model. Examples are given applying the new procedure to different multicomponent reaction systems. The results show good agreement with previous calculations using a different equation of state, demonstrating the capability of performing CPE calculations with UNIWAALS.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
A SYSTEMATIC RISK ASSESSMENT APPROACH FOR SECURING THE SMART IRRIGATION SYSTEMSIJNSA Journal
The smart irrigation system represents an innovative approach to optimize water usage in agricultural and landscaping practices. The integration of cutting-edge technologies, including sensors, actuators, and data analysis, empowers this system to provide accurate monitoring and control of irrigation processes by leveraging real-time environmental conditions. The main objective of a smart irrigation system is to optimize water efficiency, minimize expenses, and foster the adoption of sustainable water management methods. This paper conducts a systematic risk assessment by exploring the key components/assets and their functionalities in the smart irrigation system. The crucial role of sensors in gathering data on soil moisture, weather patterns, and plant well-being is emphasized in this system. These sensors enable intelligent decision-making in irrigation scheduling and water distribution, leading to enhanced water efficiency and sustainable water management practices. Actuators enable automated control of irrigation devices, ensuring precise and targeted water delivery to plants. Additionally, the paper addresses the potential threat and vulnerabilities associated with smart irrigation systems. It discusses limitations of the system, such as power constraints and computational capabilities, and calculates the potential security risks. The paper suggests possible risk treatment methods for effective secure system operation. In conclusion, the paper emphasizes the significant benefits of implementing smart irrigation systems, including improved water conservation, increased crop yield, and reduced environmental impact. Additionally, based on the security analysis conducted, the paper recommends the implementation of countermeasures and security approaches to address vulnerabilities and ensure the integrity and reliability of the system. By incorporating these measures, smart irrigation technology can revolutionize water management practices in agriculture, promoting sustainability, resource efficiency, and safeguarding against potential security threats.
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
(Liquid liquid) equilibrium of systems involved in the stepwise ethanolysis of vegetable oils
1. (Liquid + liquid) equilibrium of systems involved in the stepwise
ethanolysis of vegetable oils
Larissa C.B.A. Bessa, Marcela C. Ferreira, Simone Shiozawa, Eduardo A.C. Batista, Antonio J.A. Meirelles ⇑
Laboratory of Extraction, Applied Thermodynamics and Equilibrium, Department of Food Engineering, Faculty of Food Engineering, University of Campinas, Campinas, São
Paulo 13083-862, Brazil
a r t i c l e i n f o
Article history:
Received 10 February 2015
Received in revised form 29 April 2015
Accepted 30 April 2015
Available online 21 May 2015
Keywords:
(Liquid + liquid) equilibrium
Monoacylglycerol
Diacylglycerol
Biodiesel
Ethanol
Modelling
a b s t r a c t
Current concerns about adverse impacts to the environment and human health have encouraged the
research and development of renewable fuels, such as biodiesel. The transesterification reaction is a
three-stage reaction, which produces two intermediate products (diacylglycerols and monoacylglyc-
erols). Accurate and proper knowledge of the phase equilibrium behaviour during the transesterification
process is crucial for a better understanding of the reaction pathway, for the optimisation of reactors and
the separation of the products. Thus, in order to thoroughly understand the entire transesterification sys-
tem for biodiesel production, which consists of six different kinds of components, this study reports
experimental results and the thermodynamic modelling of the (liquid + liquid) equilibrium (LLE) of
two systems composed by {vegetable oils (sunflower or high oleic sunflower oils) + monoacylglyc-
erols + diacylglycerols (+ethyl esters + fatty acids) + ethanol} at T = (303.15 and 318.15) K, at atmospheric
pressure. The LLE experimental values were used to estimate NRTL parameters and to evaluate the
UNIFAC model, using its original version with two different set of parameters. Results showed that,
due to differences in the number of polar groups, mono- and diacylglycerols behave in opposite ways
regarding phase distribution. Experimental data were well correlated using NRTL, in which the maximum
deviation value was 0.434%. As for UNIFAC, the model predicted the experimental data with deviations
varying within the range of (1.80 to 9.24)%.
Ó 2015 Elsevier Ltd. All rights reserved.
1. Introduction
Due to environmental adversities and the global concern about
the conservation of non-renewable natural resources, combined
with the growing sensitivity to the global warming, a search for
environmentally friendly renewable energy sources, such as bio-
diesel, has gained recent significant attention [1]. Biodiesel, defined
as mono-alkyl esters of fatty acids from vegetable oils or animal
fats, is an environmentally attractive alternative to conventional
petroleum diesel fuel. It presents many important technical advan-
tages over petroleum diesel, including low toxicity, derivation from
renewable feedstock, superior biodegradability, negligible sulfur
content, higher flash point and lower exhaust emissions [2].
The process used most often for the biodiesel production is the
transesterification (alcoholysis), a reaction between triacylglyc-
erols (TAG) found in oils and fats and an alcohol in the presence
of a catalyst (such as a base, an acid or an enzyme). Methanol is
the most often used alcohol in biodiesel synthesis because of its
suitable physical and chemical properties and low cost [3].
However, the advantages of using ethanol in biodiesel production
include higher miscibility with vegetable oils that allows better
contact in the reaction step and lower toxicity [4].
Transesterification produces methyl or ethyl esters, according to
the selected alcohol.
The reaction typically follows three steps, as shown in figure 1,
where each fatty acid is sequentially taken out and converted to a
molecule of fatty acid alkyl ester (biodiesel). The reaction (1) con-
verts triacylglycerol (TAG) plus alcohol into diacylglycerol (DAG)
plus a fatty acid alkyl ester. Subsequently, the reaction (2) gener-
ates monoacylglycerol (MAG) and another fatty acid alkyl ester.
Finally, reaction (3) generates glycerol and a third fatty acid alkyl
ester. Thus, complete conversion of one mole of TAG generates
three moles of biodiesel [5]. This reaction is essentially biphasic
from the beginning to the end under the reaction conditions usu-
ally employed in the industrial process [6].
Unconverted triacylglycerols, diacylglycerols, monoacylglyc-
erols, glycerol, water and other undesirable components could
http://dx.doi.org/10.1016/j.jct.2015.04.036
0021-9614/Ó 2015 Elsevier Ltd. All rights reserved.
⇑ Corresponding author. Tel.: +55 19 3521 4037; fax: +55 19 3521 4027.
E-mail addresses: larissacbabessa@gmail.com (L.C.B.A. Bessa), marcela.cravo@
gmail.com (M.C. Ferreira), sshiozawa@gmail.com (S. Shiozawa), eacbat@fea.
unicamp.br (E.A.C. Batista), tomze@fea.unicamp.br (A.J.A. Meirelles).
J. Chem. Thermodynamics 89 (2015) 148–158
Contents lists available at ScienceDirect
J. Chem. Thermodynamics
journal homepage: www.elsevier.com/locate/jct
2. cause significant engine damages and their loss of power.
Therefore, high conversion and purification steps are of utmost
importance for biodiesel production [7]. Some of the drawbacks
of the industrial ethylic biodiesel production are associated with
the lack of knowledge of the phase compositions during the reac-
tion process. Thus, the measurement and modelling of equilibrium
data, including the equilibrium involved in the steps of oil extrac-
tion, de-acidification, transesterification reaction and purification
of the biodiesel, should be carried out in order to properly optimise
operating conditions for economical and efficient ethylic biodiesel
purification and alcohol recuperation processes.
(Liquid + liquid) equilibrium involving alkyl esters, methanol,
ethanol and glycerol systems, which correspond to the end of the
transesterification reaction, have been extensively published in
the literature in recent years [8–14], as well as the equilibrium
involving vegetable oils, fatty acid and ethanol, which represents
the initial stage of the reaction. [15–18]. However, phase equilib-
rium data taking into account the presence of partial acylglycerols
are limited. Voll et al. [19] determined (liquid + liquid) equilibrium
of hydrolysed palm oil, containing tri-, di- and monoacylglycerols
and free fatty acids in its composition, with water and ethanol, in
order to enrich the palm oil diacylglycerol content by (liquid + liq-
uid) extraction. Oh et al. [20] and Casas et al. [6] discussed the (liq-
uid + liquid) equilibrium results for the system triacylglycerol,
fatty acid methyl esters, methanol, glycerol, diacylglycerol and
monoacylglycerol involved in the methanolysis of crude palm oil
and soybean oil, respectively. Even though, phase equilibrium data
involving both partial acylglycerols and ethyl esters, required for
some of the reactive and purification steps of the ethylic biodiesel
production, are still scarce.
In this context, the main objective of this study was to enhance
the experimental data bank by providing information on the (liq-
uid + liquid) equilibrium (LLE) related to systems that could be
involved in biodiesel production and its purification processes,
with special emphasis on phase equilibrium associated with the
transesterification and esterification reactions. Thus, LLE values
were determined using two different vegetable oils (sunflower
and high oleic sunflower oils), two kinds of commercial mixtures
of mono- and diacylglycerols from different sources (soybean and
cottonseed oils) and two different ethyl esters (oleate and linole-
ate), so that each system consists of derivatives of different major
fatty acid (oleic or linoleic). High oleic sunflower oil is derived from
a high-oleic variety of the sunflower plant. It has an exceptional
oxidative stability due to the reduction in linoleic acid content
[21].
The experimental results include the following kinds of
systems: (vegetable oil + diacylglycerols + monoacylglycerols +
ethanol), (vegetable oil + diacylglycerols + monoacylglyc-
erols + ethyl ester + ethanol) and (vegetable oil + diacylglyc-
erols + monoacylglycerols + fatty acid + ethyl ester + ethanol), so
that the LLE was measured for multicomponent systems. In addi-
tion, these experimental values were used to adjust all binary
interaction parameters of the NRTL model and to evaluate two dif-
ferent sets of parameters of the UNIFAC original model.
2. Experimental
2.1. Material
The suppliers and the mass fraction purity of the solvents and
fatty compounds used in this work are listed in table 1; none of
them was subjected to further purification.
CH2
CH O
O
CH2 O
C
C R2
C R3
O
O
O
R1
OHR
TAG Alcohol Ester
CH2
CH O
O
CH2 OH
C
C R2
O
O
R1
O C R3
O
R
DAG
(1)
OHR
Alcohol Ester MAG
O C
O
R1R
CH2
CH O
OH
CH2 OH
C R2
O
(2)
CH2
CH O
O
CH2 OH
C
C R2
O
O
R1
DAG
OHR
CH2
CH OH
OH
CH2 OH
MAG Alcohol Ester Glycerol
CH2
CH O
OH
CH2 OH
C R2
O
O C R2
O
R
(3)
FIGURE 1. Generalized scheme of the transesterification steps for the production of biodiesel from triacylglycerols.
TABLE 1
Reagents and fatty compounds used in this work, its suppliers and mass fraction
purity.
Component Supplier Mass fraction
puritya
Ethanol Merck >0.995
Toluene HPLC grade Sigma Aldrich >0.999
Acetic acid Merck >0.998
Sunflower oil Cargill >0.999e
HOSOb
Cargill >0.999e
Mixture Ac
SGS Agriculture and Industry
Ltd.
>0.52f
Mixture Bd
SGS Agriculture and Industry
Ltd.
>0.52f
Commercial ethyl oleate Tecnosyn >0.75
Commercial ethyl linoleate Sigma Aldrich >0.65
a
As reported by the supplier.
b
High oleic sunflower oil.
c
Commercial mixtures of mono- and diacylglycerols from cottonseed oil.
d
Commercial mixtures of mono- and diacylglycerols from soybean oil.
e
Of fatty compounds.
f
Of monoacylglycerols.
L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158 149
3. 2.2. Experimental procedure
All fatty compounds used were converted to fatty acid methyl
esters as reported by Hartman and Lago [22], and analysed by
gas chromatography in order to determine the fatty acid composi-
tion according to the official method Ce 1f-96 of the American Oil
Chemists’ Society (AOCS) [23]. The compositions of the commercial
ethyl oleate and ethyl linoleate were also determined by gas
chromatography.
The analysis of fatty acid composition using the aforementioned
method is a simple way to characterise oils and fats because it
reduces the number of their constituents to no more than 18 to
20 fatty acids. On the other hand, their TAG composition includes
much more than 100 components, if it is taken into account triacyl-
glycerols with different fatty acid connected to the glycerol residue
and the corresponding different types of isomerism. A detailed
experimental analysis of oils and fats, in terms of TAGs, can be car-
ried out by liquid or gas chromatography, but the identification of
the chromatographic peaks, sometimes even for major compo-
nents, requires a lot of knowledge and parallel information, since
the required set of pure standards is often not available, attributing
a relatively high uncertainty to these analyses.
Owing to this difficulty in analysing these components experi-
mentally, the probable triacylglycerol composition of the vegetable
oils was calculated using the statistical algorithm suggested by
Antoniosi Filho et al. [24]. These authors compared results acquired
by the proposed method with those obtained by gas chromatogra-
phy for several vegetable oils and observed high correlation
between the gas chromatographic data and the statistical ones.
The statistical method results in a very large number of TAGs
and in order to reduce the number of components, all structural
isomers were added up in a set of components with x carbons
and y double bonds and named according to the major TAG in this
isomer set. The groups with a total TAG concentration less than
0.5 wt.% were ignored.
(Liquid + liquid) equilibrium results for the systems containing
{sunflower oil + mixture A (+ethyl linoleate) + ethanol} and
{HOSO + mixture B (+ethyl oleate + oleic acid) + ethanol} were
determined at T = (303.15 and 318.15) K, at atmospheric pressure.
These values were determined using a sealed headspace glass
tubes (10 mL) (Perkin Elmer). Components were weighted on an
analytical balance (Precisa, model XT220A, Sweden, ±0.0001 g).
The tubes were vigorously stirred using a vortex (IKA, model
Genius3) for 30 min. All systems were left to rest for at least 36 h
with temperature controlled in a thermostatic bath Cole Parmer,
model Polystat (T/K ± 0.01). Two clear layers and a well-defined
interface were formed when the systems reached the equilibrium
state, the upper layer being the alcoholic phase (AP), and the lower
layer the oil-rich phase (OP). At the end of the experiment, samples
of both phases were carefully collected using syringes and diluted
directly with toluene to guarantee an immediate dilution of the
samples and avoid further separation into two liquid phases at
ambient temperature. The compounds of each phase were identi-
fied and quantified.
The quantification of ethyl esters, acylglycerols and ethanol was
conducted in a HPLC (High-Performance Liquid Chromatography)
Shimadzu, model 20AT, equipped with a single 10.0 nm Phenogel
size exclusion column (300 Á 7.8 mm ID, 5 lm) (Phenomenex,
Torrance, CA, USA), a RI detector (RID-10A), a model CTO-10AS
VP column oven set at 40 °C, a model CBM-20A system controller
and a LC-Solution 2.1 software for data acquisition. Elution was
carried out in isocratic mode using 0.25% (v/v) acetic acid in
toluene at a flow rate of 1.0 mL Á minÀ1
. An auto sampler and injec-
tor were used to inject 20 lL of the sample into the HPLC system
[25,26]. This methodology was also used to qualitatively analyse
all fatty reagents used in this study.
The quantitative determination was carried out using calibra-
tion curves (external calibration) obtained by using solutions made
with the same reagents used in the equilibrium systems. The com-
pounds were diluted with toluene in the concentration range from
(0.18 to 52) mg Á mLÀ1
. The values obtained were fitted by linear
TABLE 2
Fatty acid composition of fatty reagents (% mass).a
Fatty acid/ethyl ester Symbol Cx:yb
Sunflower oil HOSO Mixture A Mixture B Ethyl oleate Ethyl linoleate
Dodecanoic L C12:0 0.02 0.04 2.54
Tetradecanoic M C14:0 0.07 0.05 0.72 0.09 0.29 0.11
Hexadecanoic P C16:0 6.15 3.86 22.08 11.38 4.62 7.98
9-Hexadecenoic Po C16:1 0.09 0.09 0.47 0.08 0.10
Octadecanoic S C18:0 3.38 2.90 2.33 5.52 1.84 2.27
cis-9-Octadecenoic O C18:1 31.68 80.94 16.45 23.38 78.08 12.61
cis-9,cis-12-Octadecadienoic Li C18:2 57.32 10.44 57.02 52.21 11.93 76.38
trans-9,trans-12-Octadecadienoic Li Tc
C18:2 Tc
2.57
All-cis-9,12,15-octadecatrienoic Le C18:3 0.16 0.31 0.24 3.53 0.20
All-trans-9,12,15-octadecatrienoic Le Tc
C18:3 Tc
0.28 0.20
Icosanoic A C20:0 0.28 0.29 0.21 0.41 0.08 0.07
cis-9-Icosenoic Ga C20:1 0.16 0.25 0.05 0.14 0.08 0.19
Docosanoic B C22:0 0.71 0.87 0.13 0.45 0.13 0.09
13-Docosenoic E C22:1 0.41
a
Standard uncertainties u are u(w/%) = 0.02.
b
Cx:y: x is the number of carbons and y is the number of double bonds.
c
Trans isomers.
TABLE 3
Probable triacylglycerol compositions of the vegetable oils.a
Group
x:yb
Main
TAG
M/g Á molÀ1
Sunflower oil HOSO
% molar % mass % molar % mass
50:2 PPLi 831.35 0.84 0.80
52:2 OOP 859.41 2.85 2.79 8.95 8.70
52:3 POLi 857.39 7.54 7.36 2.51 2.44
52:4 LiLiP 855.38 6.96 6.78
54:2 OOS 887.46 1.29 1.31 6.09 6.12
54:3 OOO 885.45 6.95 7.01 55.27 55.42
54:4 OOLi 883.43 20.87 21.00 21.09 21.10
54:5 LiLiO 881.41 31.93 32.04 3.36 3.35
54:6 LiLiLi 879.40 19.53 19.57
56:2 OOA 915.51 0.61 0.63
56:3 OOGa 913.50 0.60 0.62
58:2 OOBe 943.57 1.52 1.62
58:3 OLiBe 941.55 0.65 0.70
58:4 LiLiBe 939.54 0.59 0.64
a
Standard uncertainties u are u(x/%) = 0.5.
b
x:y, x = number of carbons (except carbons of glycerol) and y = number of double
bonds.
150 L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158
4. regression and the corresponding equations were generated for
quantification.
To verify the quality of the results, the procedure developed by
Marcilla et al. [27] and previously applied to fatty systems by
Rodrigues et al. [28] was utilised. According to Marcilla et al.
[27], values of global mass balance deviation less than 0.5% ensure
the good quality of the experimental data. The global mass balance
deviation corresponds to the difference between the sums of the
calculated mass in both liquid phases and the actual value for total
mass used in the experiment, divided by the total mass.
2.3. Thermodynamic modelling
2.3.1. NRTL modelling approach
The experimental values determined were used to adjust all
binary interaction parameters of the NRTL model. Parameters
adjustments were made by considering the systems as if they were
composed by a single triacylglycerol, representatives of diacylglyc-
erol and monoacylglycerol, ethyl linoleate or ethyl oleate, ethanol
and oleic acid, when applied, so that the systems studied are com-
posed by up to 6 components. The molar masses Mi of the repre-
sentative tri-, di- and monoacylglycerol and ethyl esters were,
respectively, determined from the molar composition of the veg-
etable oils, commercial mixtures of mono- and diacylglycerols
and the commercial ethyl esters.
The binary parameters were obtained according to the proce-
dure developed by Stragevitch and d’Ávila [29], using the modified
simplex method by the minimisation of the composition objective
function defined as:
S ¼
XD
m¼1
XN
n¼1
XPÀ1
i¼1
wFI;exp
inm À wFI;calc
inm
rwFI
inm
!2
þ
wFII;exp
inm À wFII;calc
inm
rwFII
inm
!2
2
4
3
5; ð1Þ
TABLE 4
Probable tri-, di- and monoacylglycerol compositions of the commercial mixture A.a
Main TAG M/g Á molÀ1
% molar DAG M/g Á molÀ1
% molar MAG M/g Á molÀ1
% molar
MLiP 803.30 0.71 MP 540.85 0.24 M 302.43 0.85
PPP 807.33 1.39 MO 566.89 0.33 P 330.48 16.19
PPO 833.37 2.80 MLi 564.88 1.13 Po 328.47 7.72
PPLi 831.35 9.89 PP 568.91 5.62 S 358.54 0.18
MLiO 829.34 0.98 PoLi 590.91 15.44 O 356.52 19.53
LiLiM 827.32 0.84 PS 596.96 0.18 Li 354.51 55.54
POS 861.42 0.54 PO 594.95 8.90
OOP 859.41 3.71 PLi 592.93 11.82
POLi 857.39 13.13 SO 623.00 0.18
LiLiP 855.38 23.16 OO 620.98 5.13
LiLiPo 853.36 0.91 OLi 618.97 19.40
OOO 885.45 1.70 LiLi 616.95 31.65
OOLi 883.43 6.58
LiLiO 881.41 15.46
LiLiLi 879.40 18.19
a
Standard uncertainties u are u(x/%) = 0.5.
TABLE 5
Probable tri-, di- and monoacylglycerol compositions of the commercial mixture B.a
Main TAG M/g Á molÀ1
% molar DAG M/g Á molÀ1
% molar MAG M/g Á molÀ1
% molar
PPO 833.37 1.03 PP 568.91 1.16 P 330.48 12.49
PPLi 831.35 2.46 OS 596.96 0.30 S 358.54 2.78
LiLiP 855.38 13.01 PO 594.95 7.36 O 356.52 26.87
PLeLi 853.36 1.76 PLi 592.93 14.41 Li 354.51 56.13
POS 861.42 0.90 PLe 590.91 0.59 Le 352.49 1.72
OOP 859.41 4.30 SO 623.00 3.31
POLi 857.39 10.54 SLi 620.98 1.95
OOS 887.46 1.59 OO 620.98 6.74
SOLi 885.45 5.86 OLi 618.97 29.59
OOLi 883.43 14.35 LiLi 616.95 31.73
LiLiO 881.41 21.84 LiLe 614.94 2.86
LiLiLi 879.40 18.97
LiLiLe 877.38 3.41
a
Standard uncertainties u are u(x/%) = 0.5.
TABLE 6
Composition of the vegetable oils and commercial mixtures A and B (% mass).a
Mass fraction
Sunflower oil HOSO Mixture A Mixture B
TAG 99.33 99.00 6.49 5.26
DAG 0.67 1.00 32.35 34.86
MAG 61.16 59.89
a
Standard uncertainties u are u(w/%) = 0.46.
TABLE 7
Probable diacylglycerol compositions of the vegetable oils.a
Mole per cent
DAG M/g Á molÀ1
Sunflower oil HOSO
PP 568.91 0.28
PO 594.95 4.41 6.80
PLi 592.93 7.72 0.84
SO 623.00 0.86 4.06
OO 620.98 15.29 68.22
OLi 618.97 37.92 17.14
LiLi 616.95 32.69 1.12
AO 651.05 0.41
OGa 649.04 0.40
OBe 679.11 0.22 1.01
LiBe 677.09 0.61
a
Standard uncertainties u are u(x/%) = 0.5.
L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158 151
5. where D is the total number of data sets, N is the total number of tie
lines, P is the total number of components in each data set; i, n, and
m stand for component, tie line and data group, respectively; FI and
FII refer to phases I and II, respectively; exp and calc stand for exper-
imental and calculated mass fractions (w), respectively, rwOP
inm
and
rwAP
inm
are the standard deviations observed in the composition of
the two liquid phases.
The deviations between experimental and calculated composi-
tions in both phases were calculated using the root mean square
deviation (Dw/%), which is given by the following equation:
Dw ¼ 100
XN
n¼1
XP
i¼1
wFI;exp
i;n À wFI;calc
i;n
2
þ wFII;exp
i;n À wFII;calc
i;n
2
2NP
0
B
B
B
B
@
1
C
C
C
C
A
1=2
:
ð2Þ
2.3.2. UNIFAC modelling approach
The UNIFAC thermodynamic model was used to predict the LLE
of the system. Structural groups selected to represent the studied
systems were ‘‘CH3’’, ‘‘CH2’’, ‘‘CH’’, ‘‘CH = CH’’, ‘‘CH2COO’’,
‘‘COOH’’ and ‘‘OH’’.
Two sets of interaction parameters were used to test the predic-
tion capability of LLE data. In both cases, the model used was that
presented by Fredenslund et al. [30], and the set of binary interac-
tion parameters denoted as UNIFAC-LLE is that updated by
Magnussen et al. [31]. The set of parameters here referred to as
UNIFAC-HIR was presented by Hirata et al. [32], wherein the
authors used several data for real multicomponent oil
de-acidification systems to readjust group interaction parameters.
Those systems were composed by several triacylglycerols and fatty
acids, ethanol and water. All individual components – tri-, di- and
monoacylglycerols, and ethyl esters – were considered for UNIFAC
modelling calculations.
3. Results
Through the size exclusion chromatography (HPSEC) it was pos-
sible to identify the classes of compounds present in each fatty
reagent used in this study. Thus, it was observed that the commer-
cial mixtures of mono- and diacylglycerols, besides these compo-
nents, also contain a small amount of triacylglycerols. In
addition, it was identified the presence of a very small amount of
diacylglycerols in the vegetable oils and the presence of fatty acids
in the commercial ethyl oleate. The quantification of these com-
pounds will be discussed later.
The fatty acid composition of the vegetable oils and the com-
mercial mixtures of mono- and diacylglycerols are presented in
table 2, as well as the ethyl ester composition of the commercial
ethyl oleate and ethyl linoleate.
Table 3 shows the probable TAG compositions of the sunflower
and high oleic sunflower oils. The names given to the main TAG in
table 3 are related to the symbols used for each fatty acid in table 2,
i.e., the TAG named POLi, for instance, is a triacylglycerol composed
by palmitic acid (P), oleic acid (O) and linoleic acid (Li). The same
applies to all the other TAGs.
TABLE 8
Average molar masses of each pseudocomponent.
Pseudocomponent M/g Á molÀ1
TAG_sunflower oil 877.86
TAG_HOSO 883.21
DAG_mixture A 605.08
DAG_mixture B 612.19
MAG_mixture A 348.57
MAG_mixture B 352.12
Ethyl oleate 306.33
Ethyl linoleate 306.79
Oleic acid 282.46
Ethanol 46.07
TABLE 9
(Liquid + liquid) equilibrium values for the system {sunflower oil (1)a
+ DAG1 (3) + MAG1 (5) (+ethyl linoleate (7)) + ethanol (10)} at T = (303.15 and 318.15) K, and P = 93.8 kPa.b
T/K Overall Composition Alcoholic phase Oil phase d/%c
w1 w3 w5 w7 w10 w1 w3 w5 w7 w10 w1 w3 w5 w7 w10
303.15 0.4969 0.0034 0.0000 0.0000 0.4997 0.0578 0.0026 0.0000 0.0000 0.9396 0.8630 0.0048 0.0000 0.0000 0.1322 0.05
0.4415 0.0223 0.0367 0.0000 0.4995 0.0997 0.0187 0.0550 0.0000 0.8266 0.7762 0.0265 0.0194 0.0000 0.1779 0.07
0.4041 0.0346 0.0603 0.0000 0.5010 0.1340 0.0293 0.0825 0.0000 0.7542 0.7095 0.0397 0.0373 0.0000 0.2135 0.06
0.3863 0.0413 0.0732 0.0000 0.4992 0.1643 0.0364 0.0960 0.0000 0.7033 0.6641 0.0468 0.0467 0.0000 0.2424 0.06
0.3658 0.0480 0.0862 0.0000 0.5000 0.2081 0.0439 0.1038 0.0000 0.6442 0.6142 0.0532 0.0598 0.0000 0.2728 0.01
0.3516 0.0524 0.0947 0.0000 0.5013 0.2498 0.0490 0.1070 0.0000 0.5942 0.5648 0.0573 0.0702 0.0000 0.3077 0.02
0.4740 0.0111 0.0150 0.0000 0.4999 0.0810 0.0092 0.0234 0.0000 0.8864 0.8123 0.0137 0.0073 0.0000 0.1667 0.02
0.4518 0.0114 0.0157 0.0208 0.5003 0.0873 0.0094 0.0235 0.0149 0.8649 0.7806 0.0136 0.0080 0.0247 0.1731 0.08
0.4332 0.0113 0.0159 0.0406 0.4990 0.0952 0.0092 0.0229 0.0294 0.8433 0.7391 0.0129 0.0087 0.0483 0.1910 0.18
0.4040 0.0105 0.0148 0.0703 0.5004 0.1094 0.0086 0.0205 0.0523 0.8092 0.6796 0.0118 0.0088 0.0832 0.2166 0.25
0.3849 0.0108 0.0156 0.0887 0.5000 0.1355 0.0095 0.0210 0.0731 0.7609 0.6453 0.0122 0.0089 0.1064 0.2272 0.01
0.3632 0.0109 0.0159 0.1096 0.5004 0.1429 0.0093 0.0199 0.0900 0.7379 0.5947 0.0118 0.0107 0.1271 0.2557 0.21
318.15 0.4970 0.0034 0.0000 0.0000 0.4996 0.0774 0.0025 0.0000 0.0000 0.9201 0.8557 0.0044 0.0000 0.0000 0.1399 0.02
0.4738 0.0113 0.0153 0.0000 0.4996 0.0908 0.0084 0.0233 0.0000 0.8775 0.8234 0.0143 0.0076 0.0000 0.1547 0.00
0.4599 0.0160 0.0244 0.0000 0.4997 0.1007 0.0122 0.0368 0.0000 0.8503 0.8001 0.0189 0.0129 0.0000 0.1681 0.02
0.4410 0.0225 0.0369 0.0000 0.4996 0.1140 0.0176 0.0528 0.0000 0.8156 0.7656 0.0259 0.0202 0.0000 0.1883 0.12
0.4133 0.0321 0.0555 0.0000 0.4991 0.1385 0.0268 0.0764 0.0000 0.7583 0.7190 0.0363 0.0322 0.0000 0.2125 0.09
0.3858 0.0411 0.0730 0.0000 0.5001 0.1754 0.0367 0.0935 0.0000 0.6944 0.6455 0.0450 0.0481 0.0000 0.2614 0.05
0.4636 0.0116 0.0160 0.0096 0.4992 0.0979 0.0099 0.0213 0.0074 0.8635 0.7885 0.0132 0.0089 0.0108 0.1786 0.16
0.4429 0.0113 0.0157 0.0306 0.4995 0.1054 0.0089 0.0238 0.0227 0.8392 0.7451 0.0125 0.0091 0.0349 0.1984 0.17
0.4243 0.0111 0.0155 0.0497 0.4994 0.1184 0.0090 0.0230 0.0386 0.8110 0.7001 0.0122 0.0094 0.0573 0.2210 0.12
0.3945 0.0107 0.0151 0.0796 0.5001 0.1392 0.0095 0.0222 0.0669 0.7622 0.6371 0.0115 0.0099 0.0907 0.2508 0.02
0.3730 0.0106 0.0154 0.1015 0.4995 0.1445 0.0085 0.0203 0.0844 0.7423 0.5869 0.0112 0.0108 0.1150 0.2761 0.18
a
Includes only TAG.
b
Standard uncertainties u are u(T/K) = 0.1, u(P/kPa) = 0.3, u(w) = 0.0022.
c
Overall mass balance deviation [27].
152 L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158
7. For the commercial mixtures of mono- and diacylglycerols, the
probable TAG compositions were determined using the same pro-
cedure and, from these compositions, the compositions in mono-
and diacylglycerols were estimated considering the probability of
the partial rupture of the triacylglycerols without preference for
specific ester bonds. Tables 4 and 5 present the probable TAG,
DAG and MAG compositions of the commercial mixtures A and B,
respectively, where the symbols given to DAGs follow the same
reasoning aforementioned for the TAGs. Note that the composi-
tions of each class of components, viz. TAG, DAG and MAG, pre-
sented in tables 4 and 5, sum to 100%.
The concentration of fatty acids in the commercial ethyl oleate
was determined by titration according to the official method 2201
of the IUPAC [33] with an automatic buret (Metrohm, Model
Dosimat 715). The analysis was replicated three times and the
average value is 8.43 wt.%, expressed in oleic acid.
As for the commercial mixtures A and B, the quantification of
mono-, di- and triacylglycerols was performed by gas chromatog-
raphy with flame ionisation detector, according to the official
method ASTM D 6585 [34]. This analysis was carried out at the
Analytical Center of the Institute of Chemistry at the University
of Campinas (IQ/UNICAMP), and the results are presented in table
6. Having these compositions, calibration curves were made with
the commercial mixtures A and B and the angular coefficients
obtained for the diacylglycerols were used to determine the DAG
compositions in the vegetable oils, which are also presented in
table 6. The correct and detailed characterisation of input materials
allowed the construction of calibration curves in order to thor-
oughly describe the equilibrium phases obtained in the experi-
ments in terms of their various classes of components.
Despite being very small, the composition of DAG in the veg-
etable oils was taken into account in both the experimental data
and in the thermodynamic calculations. However, in the case of
the NRTL model, the molar masses Mi of the representative DAG
were calculated considering only the molar composition of the
commercial mixtures of mono- and diacylglycerols. The average
molar masses of diacylglycerols from mixture A and mixture B
were calculated according to tables 4 and 5, and the values
obtained were M = (605.08 and 612.19) g Á molÀ1
for DAGs from
mixtures A and B, respectively. It is worth mentioning that the
error introduced by considering only the compositions of the com-
mercial mixtures in the DAGs molar masses calculation is fairly
small, since the amount of DAGs in the vegetable oils are quite
low, as already mentioned, and because the average molar masses
of DAGs from vegetable oils (M = (615.93 and 614.10) g Á molÀ1
for
DAGs from sunflower oil and HOSO, respectively) do not differ sig-
nificantly from those calculated for the commercial mixtures.
These average molar masses were calculated according to the dia-
cylglycerols compositions of the vegetable oils, presented in table
7, which were estimated in the same way as for the mixtures A
and B.
Similarly, the TAG content in the commercial mixtures of mono-
and diacylglycerols was also taken into account, but, due to the
same reasons presented above, the average molar masses were cal-
culated considering only the molar composition of the vegetable
oils. According to table 3, the obtained values were M = (877.86
and 883.21) g Á molÀ1
for sunflower and high oleic sunflower oils,
respectively.
The average molar masses of monoacylglycerols from mixtures
A and B were calculated according to tables 4 and 5, obtaining the
values of M = (348.57 and 352.12) g Á molÀ1
for MAGs from mixture
A and B, respectively. Average molar masses of the commercial
ethyl oleate and ethyl linoleate were determined from their ethyl
ester composition presented in table 2. The obtained values were
M = (306.33 and 306.79) g Á molÀ1
, respectively. The average molar
masses of each pseudo component considered in the NRTL mod-
elling is summarised in table 8.
Regarding the UNIFAC model, all different components were
considered in the calculation, i.e., all tri- and diacylglycerols from
vegetable oils, all tri-, di- and monoacylglycerols from mixtures A
and B, and all ethyl esters from commercial oleate and linoleate,
so that the compositions of the input materials were employed
as precisely as possible. This means that, in total, 62 different com-
ponents were considered.
TABLE 11
Deviations for the global mass balance of the phase compositions.
System d/%a
Sunflower oil/DAG1/MAG1/ethyl linoleate/ethanol, T = 303.15 K 0.085
Sunflower oil/DAG1/MAG1/ethyl linoleate/ethanol, T = 318.15 K 0.087
HOSO/DAG2/MAG2/ethyl oleate/oleic acid/ethanol, T = 303.15 K 0.039
HOSO/DAG2/MAG2/ethyl oleate/oleic acid/ethanol, T = 318.15 K 0.068
a
Overall mass balance deviation according to Marcilla et al. [27].
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Ki
Temperature/K
303.15 318.15
FIGURE 2. Average distribution coefficient of: e, DAG1; h, MAG1; s, ethyl linoleate; D, DAG2; Â, MAG2; +, ethyl oleate; d, oleic acid.
154 L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158
8. In the present study, the following notations were given to the
components: DAG1 for the DAGs of (sunflower oil + mixture A),
DAG2 for the DAGs of (HOSO + mixture B), and MAG1 and MAG2
for the MAGs of mixtures A and B, respectively. Tables 9 and 10
contain the values of the overall composition and the correspond-
ing tie lines for the systems composed by {sunflower oil (1) + DAG1
(3) + MAG1 (5) (+ethyl linoleate (7)) + ethanol (10)} and {HOSO
(2) + DAG2 (4) + MAG2 (6) (+ethyl oleate (8) + oleic acid
(9)) + ethanol (10)} at T = (303.15 and 318.15) K. All concentrations
are expressed in mass fraction.
The mass balances were checked and the average results
obtained for each set of experimental values are shown in table
11. In all cases, the average values were lower than 0.09%, which
indicates the good quality of the experimental data. Note that
the mass balance deviations for every tie line are also given in
tables 9 and 10 and that the highest value obtained (0.25%) is still
much lower than the maximum deviation suggested by Marcilla
et al. [27] for checking the quality of the experimental data.
The ratio between the content of the component i in the alco-
holic phase and the content of this component in the oil phase in
each tie line is called distribution coefficient. The average distribu-
tion coefficients of the components, with the corresponding error
bars, are shown in figure 2. It can be observed that for all systems
studied, the distribution coefficients of DAGs and esters were smal-
ler than unity, indicating their preference for the oil phase. On the
other hand, for MAGs and fatty acids, the distribution coefficients
were greater than unity, showing a clear preference for the alco-
holic phase.
The miscibility of a vegetable oil in ethanol is affected mainly by
the unsaturation and chain length of its fatty acids constituents
[35]. Figure 3 presents the experimental ELL values for both sys-
tems studied at T = 303.15 K. It can be observed that the
two-phase region for the system {HOSO (2) + DAG2 (4) + MAG2
(6) + ethanol (10)} is larger than the biphasic region of the system
{sunflower oil (1) + DAG1 (3) + MAG1 (5) + ethanol (10)}, indicat-
ing a greater miscibility in the case of the last system. In fact, sun-
flower oil is rich in linoleic acid, a fatty acid more unsaturated than
oleic acid, which is the major fatty acid present in HOSO. For any
given temperature, the more unsaturated the vegetable oil, the
greater is its miscibility in ethanol and, consequently, the smaller
the two-phase region.
Tables 12 and 13 contain values of the parameters of the NRTL
model adjusted to the experimental values for the two systems
studied. The deviations between the experimental and calculated
values are shown in table 14.
Figures 4 and 5 present the experimental and calculated tie
lines for the system (sunflower oil + mixture A + ethanol) at
T = 303.15 K, indicating the DAG1 and MAG1 distribution, respec-
tively. These figures confirm that those components show opposite
behaviour. This occurs because monoacylglycerols contain higher
number of polar groups (hydroxyl groups) than diacylglycerols,
increasing their solubility in ethanol. The same behaviour is
observed for DAG2 and MAG2, at both temperatures. Figure 6
shows experimental and calculated tie lines for the system (sun-
flower oil + mixture A + ethyl linoleate + ethanol) at T = (303.15
and 318.15) K. In order to have a better interpretation of the
five-component phase equilibrium, the experimental and calcu-
lated results are represented in a simplified form, showing only
the ethyl ester (w7) and ethanol (w10) compositions in a explicit
way and grouping the acylglycerols as a third pseudo component,
which consists of TAG-DAG-MAG. From that figure, it is noted that
an increase in temperature from T = (303.15 to 318.15) K causes a
small decrease in the two-phase region, indicating an improve-
ment in the mutual solubility of acylglycerols (TAG, DAG and
MAG) and ethanol. This behaviour is observed for both systems
studied and has already been reported in literature [10,12,36,37].
From figures 4–6 and table 14, it can be seen that the NRTL
model accurately described the LLE behaviour of the systems. Tie
lines calculated by the NRTL model and the experimental data
almost overlap, indicating an accurate description of the LLE and
confirming the low deviations between experimental values and
calculated compositions.
Concerning the UNIFAC, this model did not provide the same
precision, as indicated in table 14. According to figure 7, which
FIGURE 3. (Liquid + liquid) equilibrium for the systems: d, sunflower oil
(1) + DAG1 (3) + MAG1 (5) + ethanol (10), and Â, HOSO (2) + DAG2 (4) + MAG2
(6) + ethanol (10) at T = 303.15 K.
TABLE 12
NRTL parameters for the system {sunflower oil (1) + DAG1 (3) + MAG1 (5) (+ethyl linoleate (7)) + ethanol (10)}.
T = 303.15 K T = 318.15 K
Pair i-j Aij/K Aji/K aij Aij/K Aji/K aij
1-3 À992.88 À434.45 0.56984 À731.47 À447.06 0.46997
1-5 118.46 À347.69 0.10296 142.52 À321.03 0.12137
1-7 533.19 19.786 0.5319 793.26 21.109 0.57
1-10 70.866 1444.7 0.49292 54.153 1464.7 0.50555
3-5 40.941 À29.715 0.37757 90.781 À28.25 0.31806
3-7 À56.945 À306.98 0.56977 À47.73 À298.3 0.37065
3-10 140.8 À2056 0.1 118.31 À1652.9 0.10777
5-7 3247.3 À656.37 0.13493 2938.2 À1033.4 0.14639
5-10 À121.58 671.29 0.37836 À135.01 686.43 0.49335
7-10 À15.523 166.97 0.57 À45.658 201.97 0.56979
L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158 155
9. contain experimental and calculated tie lines for the system
(HOSO + mixture B + ethanol) at T = 303.15 K, using both sets of
parameters, the ethanol mass fraction was underestimated in the
oil phase and overestimated in the alcoholic phase, particularly
in the case of UNIFAC-LLE parameters. In both cases, the slope of
the calculated tie lines was more accentuated than the slope of
the experimental ones. This effect was greater when using the
UNIFAC-LLE parameters, resulting in higher deviations values.
However, using the UNIFAC-HIR set of parameters, the model pre-
dicted a different behaviour for diacylglycerols, indicating a prefer-
ence for the alcoholic phase, which is not consistent with
experimental results. These deviations can be somehow justified
by the fact that neither Magnussen et al. [31] nor Hirata et al.
[32] used experimental values involving partial acylglycerols in
their data set when adjusting the parameters. Similar improperly
description in LLE modelling of systems containing vegetable oils,
TABLE 13
NRTL Parameters for the system {HOSO (2) + DAG2 (4) + MAG2 (6) (+ethyl oleate (8) + oleic acid (9)) + ethanol (10)}.
T = 303.15 K T = 318.15 K
Pair i-j Aij/K Aji/K aij Aij/K Aji/K aij
2-4 355.85 À237.48 0.56925 428.74 À239.34 0.55624
2-6 À89.708 À63.743 0.21735 À94.895 À49.48 0.21395
2-8 À433.71 175.41 0.14045 À464.9 190.16 0.12222
2-9 7206.5 À546.15 0.10614 7621.4 À246.39 0.12729
2-10 À253.21 1757.2 0.36497 À268.53 1739.3 0.38638
4-6 1407.8 À256.19 0.1 1262.7 À343.43 0.10001
4-8 À110.07 À3165.9 0.20321 À102.26 À2775.4 0.1978
4-9 3741.4 39.494 0.14479 3112.2 42.715 0.22118
4-10 2759.3 À38.441 0.4131 2425 À37.322 0.56989
6-8 À160.15 À13.354 0.13943 À132.18 À13.578 0.15407
6-9 1855.5 631.23 0.10585 2142.3 793.5 0.10002
6-10 À327.15 940.35 0.44749 À334.06 955.19 0.45553
8-9 À59.733 À803.63 0.44596 À92.819 À782.9 0.34846
8-10 À35.525 À83.099 0.13313 À44.798 À84.608 0.11002
9-10 À474.94 339.78 0.48174 À223.97 437.6 0.41941
TABLE 14
Average deviations in phase composition.
System Dw/%
NRTL UNIFAC-LLEa
UNIFAC-HIRb
Sunflower oil/DAG1/MAG1/ethyl linoleate/ethanol, T = 303.15 K 0.434 9.237 5.070
Sunflower oil/DAG1/MAG1/ethyl linoleate/ethanol, T = 318.15 K 0.388 7.844 2.511
HOSO/DAG2/MAG2/ethyl oleate/oleic acid/ethanol, T = 303.15 K 0.348 6.305 2.781
HOSO/DAG2/MAG2/ethyl oleate/oleic acid/ethanol, T = 318.15 K 0.332 5.690 1.804
a
Original parameters [31].
b
Parameters from Hirata et al. [32].
FIGURE 4. (Liquid + liquid) equilibrium for the system {sunflower oil (1) + DAG1
(3) + MAG1 (5) + ethanol (10)} at T = 303.15 K, DAG1 distribution: d, experimental
data; - -, calculated values using NRTL.
FIGURE 5. (Liquid + liquid) equilibrium for the system {sunflower oil (1) + DAG1
(3) + MAG1 (5) + ethanol (10)} at T = 303.15 K, MAG1 distribution: d, experimental
data; - -, calculated values using NRTL.
156 L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158
10. partial acylglycerols, free fatty acids, ethanol and/or biodiesel,
using UNIFAC, has already been reported in the literature
[4,19,38,39].
On the other hand, according to values in table 14, using the
UNIFAC-HIR set of parameters, it can be observed there is an
improvement in the LLE description, and this is especially signifi-
cant taking into account the ethyl esters behaviour. Figure 8 shows
the tie lines for the system (HOSO + mixture B + ethyl oleate + oleic
acid + ethanol) at T = 303.15 K, in which similar components were
grouped up into the x-axis. The improvement in the description
using the UNIFAC-HIR set of parameters is fairly evident.
Although Hirata et al. [32] have advanced significantly in the LLE
description of systems containing vegetable oils, it can be observed
that further enhancement is still needed. The results presented in
figures 7 and 8 show that despite the availability of group interac-
tion parameters and their practical use, UNIFAC models must be
used cautiously in design analysis and process simulation of
biodiesel production due to the deviations in the prediction of
LLE for this type of system.
4. Conclusions
The results presented in this study confirm that it is indeed
important to consider the partial acylglycerols when studying the
phase equilibrium in biodiesel systems, mainly in the transesterifi-
cation step. In addition, the information acquired in this study may
also be useful for the downstream processes in cases of incomplete
conversion. It was observed that monoacylglycerols, which has a
higher number of polar groups (hydroxyl groups), have a higher
affinity with the alcoholic phase when compared to diacylglyc-
erols. The NRTL model was applied to the equilibrium results and
the binary interaction parameters were optimised for each system.
Good agreement was observed between experimental values and
the correlations, indicating the applicability of this model for such
systems. In contrast, the UNIFAC model, using two sets of parame-
ters from the literature, yielded higher deviations values, which
motivates future work to improve further the model by adjusting
a specific set of parameters. The results obtained in the present
study may allow a more accurate description of the real behaviour
of the transesterification system involved in biodiesel production
process and, consequently, its optimization.
Acknowledgements
The authors wish to acknowledge CAPES for the scholarship and
FAPESP (08/56258-8 and 09/54137-1) and CNPq (304495/2010-7
and 406856/2013-3) for the financial support.
References
[1] J.G. Veneral, D.L.R. Junior, M.A. Mazutti, F.A.P. Voll, L. Cardozo-Filho, M.L.
Corazza, E.A. Silva, J.V. Oliveira, J. Chem. Thermodyn. 64 (2013) 65–70.
[2] B.R. Moser, In Vitro Cell. Dev. Biol. Plant 45 (2009) 229–266.
[3] A.V. Marjanovic, O.S. Stamenkovic, Z.B. Todorovic, M.L. Lazic, V.B. Veljkovic,
Fuel 89 (2010) 665–671.
[4] R.C. Basso, C.A.S.D. Silva, C.D.O. Sousa, A.J.D.A. Meirelles, E.A.C. Batista,
Bioresour. Technol. 131 (2013) 468–475.
[5] K. Bozbas, Renew. Sustainable Energy Rev. 12 (2008) 542–552.
[6] A. Casas, J.F. Rodríguez, G.L. del Peso, R. Rodríguez, G. Vicente, A. Carrero, Ind.
Eng. Chem. Res. 53 (2014) 3731–3736.
FIGURE 6. (Liquid + liquid) equilibrium for the system {sunflower oil (1) + DAG1
(3) + MAG1 (5) + ethyl linoleate (7) + ethanol (10)}: j, experimental data at
T = 303.15 K; h, experimental values at T = 318.15 K; - - -, calculated values using
NRTL at T = 303.15 K; ÁÁÁÁÁÁ, calculated values using NRTL at T = 318.15 K.
FIGURE 7. (Liquid + liquid) equilibrium for the system {HOSO (2) + DAG2
(4) + MAG2 (6) + ethanol (10)} at T = 303.15 K: d, experimental values; - - -,
calculated values using UNIFAC-LLE; Á Á ÁÁ Á Á, calculated values using UNIFAC-HIR.
FIGURE 8. (Liquid + liquid) equilibrium for the system {HOSO (2) + DAG2
(4) + MAG2 (6) + ethyl oleate (8) + oleic acid (9) + ethanol (10)} at T = 303.15 K: d,
experimental values; - - -, calculated values using UNIFAC-LLE; ÁÁÁÁÁÁÁÁÁ, calculated
values using UNIFAC-HIR.
L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158 157
11. [7] G.C.S. Santana, P.F. Martins, N. de Lima da Silva, C.B. Batistella, R. Made Filho,
M.R. Wolf Maciel, Chem. Eng. Res. Des. 88 (2010) 626–632.
[8] R.C. Basso, F.H. Miyake, A.J.A. Meirelles, E.A.C. Batista, Fuel 117 (Part A) (2014)
590–597.
[9] S.C. Beneti, M. Lanza, M.A. Mazutti, M.H. Kunita, L. Cardozo-Filho, J. Vladimir
Oliveira, J. Chem. Thermodyn. 68 (2014) 60–70.
[10] J.R.F. Silva, M.A. Mazutti, F.A.P. Voll, L. Cardozo-Filho, M.L. Corazza, M. Lanza,
W.L. Priamo, J. Vladimir Oliveira, J. Chem. Thermodyn. 58 (2013) 467–475.
[11] M. Rostami, S. Raeissi, M. Mahmoodi, M. Nowroozi, J. Am. Oil Chem. Soc. 90
(2013) 147–154.
[12] M.A. Mazutti, F.A.P. Voll, L. Cardozo-Filho, M.L. Corazza, M. Lanza, W.L. Priamo,
J.V. Oliveira, J. Chem. Thermodyn. 58 (2013) 83–94.
[13] M.A. Mazutti, F.A.P. Voll, L. Cardozo-Filho, M.L. Corazza, M. Lanza, W.L. Priamo,
J.V. Oliveira, J. Chem. Thermodyn. 62 (2013) 17–26.
[14] E.F. Andrade, L. Igarashi-Mafra, M.R. Mafra, M.L. Corazza, J. Chem. Thermodyn.
47 (2012) 213–218.
[15] M. Mohsen-Nia, A. Khodayari, J. Chem. Thermodyn. 40 (2008) 1325–1329.
[16] É.C.D.A. Reipert, C.E.C. Rodrigues, A.J.A. Meirelles, J. Chem. Thermodyn. 43
(2011) 1784–1790.
[17] C.M. Oliveira, B.R. Garavazo, C.E.C. Rodrigues, J. Food Eng. 110 (2012) 418–427.
[18] M. Ansolin, R.C. Basso, A.J.D.A. Meirelles, E.A.C. Batista, Fluid Phase Equilib. 338
(2013) 78–86.
[19] F.A.P. Voll, L.R.S. Kanda, L.C. Filho, M.L. Corazza, J. Chem. Thermodyn. 58 (2013)
1–7.
[20] P.P. Oh, M.F. Chong, H.L.N. Lau, J. Chen, Y.M. Choo, Clean Technol. Environ.
Policy 15 (2013) 817–822.
[21] R.D. O’Brien, Fats and Oils: Formulating and Processing for Applications, third
ed., Taylor Francis, 2010.
[22] L. Hartman, R.C.A. Lago, Lab. Pract. 22 (1973) 475–476.
[23] AOCS, Official Methods and Recommended Practices of the American Oil
Chemists’ Society, Champaign, 2009.
[24] N.R. Antoniosi Filho, O.L. Mendes, F.M. Lanças, Chromatographia 40 (1995)
557–562.
[25] A.N.A. Aryee, L.E. Phillip, R.I. Cue, B.K. Simpson, Appl. Biochem. Biotechnol. 165
(2011) 155–177.
[26] K. Kittirattanapiboon, K. Krisnangkura, Eur. J. Lipid Sci. Technol. 110 (2008)
422–427.
[27] A. Marcilla, F. Ruiz, A.N. García, Fluid Phase Equilib. 112 (1995) 273–289.
[28] C.E.C. Rodrigues, F.A. Silva, A. Marsaioli Jr., A.J.A. Meirelles, J. Chem. Eng. Data
50 (2005) 517–523.
[29] L. Stragevitch, S.G. d’Ávila, Braz. J. Chem. Eng. 14 (1997).
[30] A. Fredenslund, R.L. Jones, J.M. Prausnitz, Am. Inst. Chem. Eng. 21 (1975) 1086–
1099.
[31] T. Magnussen, P. Rasmussen, A. Fredenslund, Ind. Eng. Chem. Process Des.
Develop. 20 (1981) 331–339.
[32] G.F. Hirata, C.R.A. Abreu, L.C.B.A. Bessa, M.C. Ferreira, E.A.C. Batista, A.J.A.
Meirelles, Fluid Phase Equilib. 360 (2013) 379–391.
[33] IUPAC, Standard methods for the analysis of oils, fats, and derivatives, seventh
ed., International Union of Pure Applied Chemistry, Applied Chemistry
Division. Commission on Oils, Fats, Derivatives, 1987.
[34] ASTM, Annual Book of ASTM Standards, ASTM International, West
Conshohocken, USA, 2013.
[35] C. Stavarache, M. Vinatoru, R. Nishimura, Y. Maeda, Ultrason. Sonochem. 12
(2005) 367–372.
[36] L.A. Follegatti-Romero, M. Lanza, C.A.S. da Silva, E.A.C. Batista, A.J.A. Meirelles,
J. Chem. Eng. Data 55 (2010) 2750–2756.
[37] C.A.S. da Silva, G. Sanaiotti, M. Lanza, L.A. Follegatti-Romero, A.J.A. Meirelles,
E.A.C. Batista, J. Chem. Eng. Data 55 (2010) 440–447.
[38] R.C. Basso, F.H. Miyake, A.J. de Almeida Meirelles, E.A.C. Batista, Fuel 117 (Part
A) (2014) 590–597.
[39] R.S. Pinheiro, A.M.M. Bessa, B.A. de Queiroz, A.M.S.F. Duarte, H.B. de Sant’Ana,
R.S. de Santiago-Aguiar, Fluid Phase Equilib. 361 (2014) 30–36.
JCT 15-86
158 L.C.B.A. Bessa et al. / J. Chem. Thermodynamics 89 (2015) 148–158