Mixture Of N-hexane Research Articles

Isobaric Binary and Ternary Vapor–Liquid Equilibrium for the Mixture of n-Hexane, Methylcyclopentane and N-Methylpyrrolidone

Isobaric Binary and Ternary Vapor–Liquid Equilibrium for the Mixture of n-Hexane, Methylcyclopentane and N-Methylpyrrolidone

Experimental screening of ionic liquids as mass agents in the n-hexane/1-hexene extractive distillation

n-Hexane and 1-hexene are highly valued compounds within the petrochemical industry because of their wide range of applications. These compounds are generally found together in the same stream. Their separation is difficult to accomplish by conventional distillation due to their close boiling points. Technologies currently used to separate n-hexane and 1-hexene at industrial scale range from membrane processes to extractive distillation and liquid-liquid extraction with organic solvents. However, these processes present several technical and environmental drawbacks. A promising alternative is extractive distillation with ionic liquids as entrainers. In this work, a screening of ten ionic liquids was made to check their potential in the extractive distillation of n-hexane and 1-hexene mixtures. Firstly, the ionic liquids’ extractive properties were determined to establish which ionic liquids are suitable for the n-hexane/1-hexene extractive distillation. Five ionic liquids, namely [4bmpy][TCM], [4bmpy][Tf2N], [bmim]2[Co(SCN)4], [P66614][TCM] and [P66614][DCA] were selected. Secondly, vapor-liquid equilibrium experiments for the binary systems {n-hexane or 1-hexene + ionic liquid} were conducted at 343.2, 363.2 and 383.2 K to select the minimum solvent-to-feed ratio that guarantees homogenous ternary systems {n-hexane + 1-hexene + ionic liquid}. Then, the vapor-liquid equilibria for the ternary systems {n-hexane + 1-hexene + ionic liquid} were determined at the same three temperatures with a solvent-to-feed ratio on a mass basis of 10. Besides, solvent-to-feed ratios of 7.5 and 5 were also used for those systems containing [P66614]-based ionic liquids. n-Hexane/1-hexene relative volatilities up to 2.3 were obtained, overcoming those provided by other ionic liquids and organic solvents. Finally, the NRTL model was used to adjust the ternary data accuracy.

Determination of Albendazole Metabolite in Livestock Products Using LC-MS/MS

A method for determining albendazole metabolite (metabolite I) in livestock products using LC-MS/MS was proposed. Livestock samples were hydrolyzed with 6 mol/L HCl at 110℃ for an hour and defatted with ethyl acetate and n-hexane (1 : 1, v/v) mixture. Metabolite I was extracted with acetonitrile from the sample, and the extracts were salted out under basic conditions, allowing the acetonitrile layer to separate. The acetonitrile solution was cleaned up using a cartridge column packed with divinylbenzene-N-vinylpyrolidone copolymer bearing sulfo groups. The HPLC separation was conducted on an Inertsil ODS-4 column with a gradient formed from water containing 0.05% (v/v) formic acid and acetonitrile containing 0.05% (v/v) formic acid. To detect metabolite I, tandem mass spectrometry with positive ion electrospray ionization was used. Truenesses (n=5) of metabolite I from cattle meat, fat, liver, and milk spiked at the maximum residue limits or the 0.01 mg/kg were in the range from 83.6 to 97.9%, and the relative standard deviations were from 1.6 to 6.1%.

Comparison of different solvents for extraction of oils from by‐products of shrimps Penaeus vannamei and Procambarus clarkia

The effects of different extraction solvents on the extraction yield and chemical composition of oils from by-products of marine shrimp Penaeus vannamei (Pv) and freshwater shrimp Procambarus clarkia (Pc) were investigated. Our results indicated that the ethanol and n-hexane mixture (4:1, v/v) was suitable solvent for simultaneous extraction of phospholipid and nonpolar lipids. By contrast, the ethanol and n-hexane mixture (4:1, v/v) and single ethanol were suitable solvents for the extraction of polyunsaturated fatty acids-rich (36.10%–42.78% of total fatty acids for Pv and 23.57%–25.58% of total fatty acids for Pc) and phosphatidylcholine-rich (66.22–67.09 mol% of total phospholipids for Pv and 55.01–58.68 mol% of total phospholipids for Pc) oils, but acetone was suitable solvent for the extraction of astaxanthin-rich oil (436.19 μg/g oil for Pv and 799.27 μg/g oil for Pc). The findings will provide relevant information that can be used to improve the production of nutritional oils from shrimp by-products. Practical applications This study provides a theoretical basis for creating proper extraction processing to recover nutritional oils from shrimp by-products. For example, the ethanol and n-hexane mixture (4:1, v/v) was a suitable solvent for simultaneous extraction of phospholipid and non-polar lipids. By contrast, both of the ethanol and n-hexane mixture (4:1, v/v) and single ethanol were suitable solvents for the extraction of polyunsaturated fatty acids (PUFA)-rich and phosphatidylcholine-rich oils, but acetone was a suitable solvent for the extraction of astaxanthin-rich oil. Therefore, the oils extracted from shrimp by-products are rich in phospholipid, PUFA, and astaxanthin, which may be used as new functional food ingredients.

Modification of Canola Oil Physicochemical Properties by Hexane and Ethanol with Regards of Its Application in Diesel Engine

A mixture of canola oil (Co), n-hexane (Hex), and ethyl alcohol (Et) was proposed as a new energy material for powering diesel engines. For this purpose, surface tension, density, and viscosity measurements, as well as engine tests, were performed for 88%Co10%Hex2%Et and 83%Co15%Hex2%Et mixtures at 20 °C. The adsorption and volumetric properties of these mixtures were compared to those of individual mixture components, as well as diesel fuel (Df) and oleic, linoleic, α-linolenic, palmitic, and stearic acids. It was revealed that the values of surface tension, viscosity, and density of Co were higher than those of the Co components. The addition of 10% Hex and 2% Et to Co caused a more than twofold decrease in its viscosity, while the addition of 15% Hex and 2% Et caused a more than fourfold reduction of Co viscosity. In addition, a mixture of Co with 2% Et and 10% Hex had a density similar to that of Df. In turn, theoretical calculations showed that the addition of n-hexane and ethanol to canola oil only slightly changed its heat of combustion. Engine tests were carried out at fixed engine rotational speeds, with a direct gearbox ratio (4th gear). The quick-changing parameters of the combustion process were registered using an AVL Indimicro system. In these tests it was found that the addition of Et to the mixture of Co and Hex did not significantly shorten the auto-ignition delay, but the kinetic phase during combustion disappeared, which had an impact on the combustion start angle.

Short- and medium-chain chlorinated paraffins in human blood serum of Czech population

Short- and medium-chain chlorinated paraffins (SCCPs; MCCPs) are widespread environmental pollutants with bioaccumulation potential and adverse effects on human health. The analysis of blood serum is an important strategy to assess the human exposure to various contaminants, including SCCPs and MCCPs. Lately, the information about the exposure of Chinese population has been reported; nevertheless, data on human exposure to SCCPs and MCCPs outside East Asia are still very limited. In this pilot study, SCCPs and MCCPs were determined in 27 serum samples obtained from Czech adults. The samples were extracted by a three-step extraction (repeated with a clean solvent) by a mixture of n-hexane:diethyl ether (9:1, v/v) with subsequent clean-up on Florisil® solid phase extraction column. Gas chromatography coupled with high resolution mass spectrometry operated in negative chemical ionisation was employed for the instrumental analysis. The method recoveries ranged from 71 to 89% with repeatabilities of <20% (expressed as relative standard deviation). In the samples, SCCP concentrations were in the range of <150–2600 ng/g lipid weight, lw (median 370 ng/g lw) and the MCCP concentrations were in the range of <200–2110 ng/g lw (median 360 ng/g lw), respectively. To the best of our knowledge, our reported results are the first data about chlorinated paraffins in human blood serum in Europe, showing exposure to these compounds with yet to be studied effects on human health.

Solubility of water in mixtures of (n-alkanes + n-perfluoroalkanes) and in n-perfluoroalkylalkanes: experiments and modelling with the SAFT-γ Mie group-contribution approach

The solubility of water in liquid n-perfluorohexane and in an equimolar mixture of n-hexane + n-perfluorohexane is experimentally determined as a function of temperature. The solubility of water in the equimolar mixture is significantly higher than the average of the solubilities in the pure solvents suggesting, for the first time, that mixing hydrogenated and perfluorinated chains enhances the solubility of water. The solubility in the equimolar mixture of n-hexane + n-perfluorohexane is also determined theoretically with the SAFT-γ Mie group-contribution approach, allowing a direct quantitative estimate of how much the large deviations from ideality contribute to the solubility of water in the mixture. In addition, the SAFT-γ Mie approach is used to represent the solubility of water in a number of n-perfluoroalkylalkanes, covering a range of relative lengths of the hydrogenated and perfluorinated chains. The theory can be used to predict the relative extent of the solubility of water in the different solvents, in good agreement with the experimental data. This is accomplished by using a single parameter to describe the strong attractive interaction between water and the CH2CF2 group at the junction between the hydrogenated and perfluorinated segments, which is known to be responsible for the increased solubility of water in these substances.

Separation of 4C-Substituted Pyrrolidin-2-One Derivatives on Amylose-Based Chiral Stationary Phases

Our previous studies concerning the enantioseparation of 4C-substituted pyrrolidin-2-one derivatives on coated polysaccharide-based chiral stationary phases have shown that amylose-based chiral selectors, together with mobile phases consisting of ethanol and n-hexane mixtures, are the most effective. To extend this research, five commercially available immobilized amylose-based chiral stationary phases (3,5-dimethylphenylcarbamate, 3-chlorophenylcarbamate, 3,5-dichlorophenylcarbamate, 3-chloro-4-methylphenylcarbamate and 3-chloro-5-methylphenylcarbamate) were tested with ethanol-containing mobile phases and obtained results were compared with data obtained on coated phases (3,5-dimethylphenylcarbamate and 5-chloro-2-methylphenylcarbamate). The effect of the nature of chiral stationary phase and analytes studied on enantiomer elution order, retention and resolution was tested. Compared to immobilized phase based on amylose 3,5-dimethylphenylcarbamate with its coated version, a better enantioseparation is observed on coated column. However, in addition to the coated amylose-based phases, immobilized phases with both methyl- and chloro-substituents in phenylcarbamate moiety were found to best separate the 4C-substituted pyrrolidin-2-one derivatives. Non-typical eluents with medium-polarity solvents were tested for the separation of three 4C-phenyl-substituted racemic compounds on five immobilized phases. Enantiorecognition of amylose derivatives containing 3,5-dimethylphenylcarbamate and 3-chloro-5-methylphenylcarbamate improved when working with mobile phases containing ethyl acetate, methyl tert-butyl ether and dichloromethane.

Structural elucidation of two unique antimicrobial Cassane – type tricyclic diterpenes from the root of CALLIANDRA PORTORICENSIS (JACQ)-BENTH (FABACEAE).

The burden of infectious diseases by bacteria and fungi had constituted a great concern to the entire human population. Calliandra portoricensis (Fabaceae) had been widely used over the years in ethnomedicine for the; treatment of various ailments such as swollen gum, tooth and throat inflammation often associated with microbial infections. At present, no active antimicrobial compound has been reported from this specie. The aim of this research was to identify, isolate and characterize the antimicrobial compounds from the root of C. portoricensis. The pulverized root sample (0.8 Kg) was extracted by successive cold maceration respectively for 72 hr. The most bioactive ethyl acetate extract (4.61 gm) was subjected to chromatographic column fractionation (Silica Gel G, 200-400 mesh-stationary phase). Gradient mixtures of n-hexane: ethyl acetate: methanol (4:0:0; 3:1:0; 2:2:0; 1:3:0; 0:1:0; 0:3:1; 0:2:2; 0:1:3; 0:0:4; – v/v/v) were used for elution. Agar well diffusion method was adopted for the bioassays susceptibility tests and MIC determinations. Clinically viable human pathogens for the tests were; Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Klebsiella pneumonia, Streptococus fecalis, Candida albicans and Aspergillus niger . Two major fractions (F A and F B ) active against the test organisms were pooled the most active fraction F B on further purification by preparative TLC (Silica Gel G, 0.5 mm thickness), yielded bioactive pure commands C 1 (9 mg) and C 2 (8 mg). Both compounds exhibited MIC values of 125.00±0.70 µg per milliliter against Candida albicans and Aspergillus niger These activities were found to be quite significant with respect to the reference controls (Ciprofloxacin and fluconazole) at P < 0.05. Characterization of C 1 and C 2 by spectroscopic analysis (UV, MS, FT – IR and NMR), identified two novel compounds as Cassane - type tricyclic diterpenoids. C 1 (Molecular Mass: 340, C 20 H 36 O 4 ) is (5,10- 8,9- 12,13)-seco - 4,4,10 – trimethyl, 7 – hydroxy, 14 – hydroxymethyl, 16 – keto, 13(15) – ene – cassane furanoditerpene and compound C 2 (Molecular Mass: 418, C 24 H 34 O 6 ) is (12,13)- seco - 12, 14 – epoxy, 12(16) -Oxo – 16(17), 13(15) – diene, 4, 10, 17 – trimethyl, 4, 7 – di – aceto cassanoate The Cassane - type diterpenoids have been reported for promising antimicrobial properties.

Stigmasterol and Stigmasterone from Methanol Extract of Calophyllum soulattri Burm. F. Stem Bark

Stigmasterol and Stigmasterone from Methanol Extract of Calophyllum soulattri Burm. F. Stem Bark. Calophyllum soulattri Burm. F. has been widely used for herbal medicine. Phytochemical investigation of C. soulattri contains a secondary metabolite of the steroid class. Steroid compounds have various biological activities, such as anti-inflammatory, antioxidant, antiproliferative, antibacterial, antimalarial, and anticancer. Two secondary metabolites steroids have been isolated and identified from the stem bark extract of C. soulattri. Isolation was carried out through the extraction (maceration), fractionation, and purification stages. Maceration is carried out using methanol as a solvent. Fractionation was carried out by vacuum liquid chromatography (VLC), and purification was by flash column chromatography. Identification of combined fractions and determination of pure isolates were used through thin-layer chromatography (TLC). The solvent used in the chromatography methods was a mixture of n-hexane and ethyl acetate. The structure isolates were identified by FTIR, 1H NMR, and 13C NMR and compared with literature data. Secondary metabolites steroids that have been isolated are identical compounds to stigmasterol and stigmasterone.

Performance of a single-stage recuperative high-temperature air source heat pump

• A single-stage recuperative high-temperature air source heat pump is developed. • Exergy efficiency of 27.97% is higher than the existed heat pumps. • Discharge pressure is less than 2 MPa at the hot water temperature 91.68 °C. • n-hexane concentration is 52.36% shifted at optimal condition. Heat energy of 75–100 °C is increasingly used in residential and industrial fields. However, conventional single-stage air source heat pumps suffer low efficiency and poor operating conditions when supplying such high-temperature heat energy. To address the challenging problems, a novel single-stage recuperative high-temperature air source heat pump prototype for tap water direct heating was developed and investigated experimentally. The intrinsic characteristic of the recuperative heat pump makes the prototype simple and components easy to gain. The key impacts of the throttle valve opening, refrigerant concentration, and water flow rate on the system performance were revealed and analyzed with the refrigerant mixture of n-hexane and propylene. Results show the excellent thermodynamic efficiency and working condition of the developed heat pump. When heating water from 23.70 °C to 91.68 °C, the system shows its optimal performance with the coefficient of performance, exergy efficiency, and compression ratio 2.83, 27.97%, and 2.86, respectively. Furthermore, based on the experiment data, systematic thermodynamic analysis on optimal condition indicated that the mass fraction of n-hexane in the cycle is about 52.36% shifted against the initial charging proportion of 36%. Finally, after system performance comparison against the CO 2 transcritical heat pump and auto-cascade heat pump, the recuperative high-temperature heat pump shows excellent efficiency and nice operating condition, which proves the developed heat pump a successful and promising application prospect.

Study of the Crude oil Properties of Oily seepages found in South Eastern Nigeria.

ASTM D-270 method was applied in obtaining well-head crude oil samples from Awoba 8T (Rivers State), Odidi 23L, and Odidi 46S (Delta State), Eremor 1L (Bayelsa State) and Oily Seepage samples from Ugwueme (Enugu State) and Anam (Anambra State). The0API gravity value of all the samples were 16.190 and 21.470 for Ugwueme seepage and Eremorcrude respectively, 22.470 for Odidi 46s crudeand 44.700, 43.840 and 34.760 for Anam seepage, Awoba 8t and Odidi 23L crudesrespectively, indicating heavy, medium and light crude oils respectively. All the well-head crudes and oily seepage samples studied in this work are onshore samples except Odidi 46s which is an offshore crude sample. The samples were subjected to liquid-liquid extraction using a mixture of n-hexane and dichloromethane (3:1). The extracted fractions were analyzed using GC-FID. The result of the analyses gave polycyclic aromatic hydrocarbons (PAHs) concentrations (mg/kg) of 7106.43 for Awoba 8T crude, 6767.41 for Odidi 23L crude, 5771.20 for Odidi 46S crude, 5191.21 for Eremor crude, 4908.04 for Ugwueme Seepage and 6983.16 for Anam seepage. The predominance of low molecular weight PAHs (LMWPs) over the high molecular weight PAHs (HMWPs) indicate that both the crude oil samples and the oily seepage samples were of Petrogenic Source. However, various ratios were obtained to identify the possible source of PAHs in the crude oil and seepage samples. Mixed sources of pyrogenic and petrogenic PAHs were also discovered with evidence of „pyrolytic‟ input which may suggest some geothermal-mediated processes.

Selective and Sensitive Quantification of Acetochlor and S-Metolachlor in Maize and Soybean Plant Samples by Gas Chromatography-Tandem Mass Spectrometry

Herbicide residue analysis has gained importance worldwide, mainly for food quality control to minimize potentially adverse impacts on human health. A Gas chromatography-tandem mass spectrometry (GC-MS) method for quantitative analysis of acetochlor and s-metolachlor in maize and soybean straw has been developed, validated and applied to analyze the residues of anilide herbicides. Straw material was dried, homogenized and extracted with a mixture of n-hexane and acetone by an accelerated solvent extraction method. Chromatographic separation of the target analytes was performed on an Agilent 7832 GC equipped with a mass spectrometer detector, a split-splitless injector and an HP-5 MS (5% phenylmethyl siloxane) capillary column (30 m × 0.25 mm × 0.25 µm). Under these parameters, the limit of detection (LOD) values were 0.2 ng g−1 for acetochlor and 0.07 ng g−1 for s-metolachlor, with average recoveries between 86% and 119.7%. The method was validated for acetochlor and s-metolachlor in maize and soybean straw at 0.5 and 0.01 mg kg −1. Furthermore, the final residues of the two herbicides in maize and soybean straw were below the maximum residue limit (MRL) at harvest time. The proposed method is suitable for routine analysis.

The first non-helical Aib-containing hexapeptide: The crystal structure of Z-Gly-Aib-Gly-Aib-Gly-Aib-OtBu.

The synthetic peptide Z-Gly-Aib-Gly-Aib-Gly-Aib-OtBu was crystallized from a mixture of ethyl acetate and n-hexane. The crystals belong to the centrosymmetric space group Pbca. There are three molecules in the asymmetric unit. The three molecules differ mainly in the Z-group conformation. The first Gly residue adopts a fully extended conformation, residues 2 and 3 lie in the left-handed helical region, residues 4 and 5 in the right-handed helical region, and residue 6 again in the left-handed helical region of the Ramachandran plot. There are only two of four possible intramolecular hydrogen bonds formed, namely, between Aib4 and Gly1 forming a β-turn of type III' and between Aib6 and Gly3 forming a β-turn of type I. The inverted molecules (by space group symmetry) lie in the regions with opposite handedness and form β-turns of type III and I'. In contrast to all known long synthetic and naturally occurring Aib-containing peptides that fold as 310 - or α-helix, Z-(Gly-Aib)3 -OtBu folds in a quite flat structure from which only the protecting groups bulge out.

Multicomponent gas transport in a Stefan diffusion column containing an azeotropic liquid mixture of acetone-n-hexane

The Stefan column was designed in the 19th Century to estimate binary gas diffusivities by placing a pure volatile liquid at the bottom overlaid with a stagnant gas. A steady gas sweep at the top removed the diffused species. Previous validation, by other research groups, of the Maxwell-Stefan multicomponent mass transport equations in the Stefan column prompted a study to test an azeotropic binary liquid as the source of both gaseous species, maintaining the composition at the liquid-gas interface constant. Azeotropic acetone (A)-n-hexane (B) mixtures were placed in a vertical glass pipette in preparation for an isothermal evaporation-diffusion experiment in atmospheric air (C). The pure solvents were also tested separately. The experimental interfacial descent, the solvents’ diffusivities in air, and their molar fluxes were provided as input to the Maxwell-Stefan equations to obtain the binary gas diffusivity DAB,exp, which is unavailable in the literature. The pure solvent diffusivities in air showed good agreement with the Chapman-Enskog kinetic theory for low-density gases, but the experimental gas diffusivity of acetone in n-hexane exceeded consistently the theoretical predictions by at least two orders of magnitude. A possible explanation for this unexpected result is the high affinity between the solvent molecules in the liquid state, which undoubtedly affects their gas transport behavior. Further studies are necessary to elucidate this finding. This is the first attempt to use a liquid azeotrope in a Stefan column. By combining this approach with the Maxwell-Stefan transport equations, the gas diffusivity of acetone in n-hexane was obtained.

Study of molecular interaction in a ternary liquid mixture of n-hexane, ethanol and benzene

An extensive theoretical study on the molecular structure of benzene, ethanol, and n-hexane monomer; their dimers and complexes were undertaken using Density Functional Theory (DFT) method. The possibility of the formation of molecular interaction was identified from structural parameter analysis and confirmed with interaction energy calculation. The information about molecular interaction was also assessed by analyzing the excess acoustic parameters. The excess thermo-acoustic parameters have been estimated from the experimentally measured ultrasonic velocity (u) and density (ρ) of the ternary mixture of n-hexane + ethanol + benzene as well as of pure components at (303, 308, 313 & 318) K using standard relation.

Superhydrophobic cotton fabric membrane prepared by fluoropolymers and modified nano-SiO2 used for oil/water separation.

At present, the preparation methods of oil–water separation membranes include chemical vapor deposition, electrospinning, atom transfer radical polymerization, etc. Basically, they all have issues of low recycling rate and incontinuous use. In this paper, the epoxy polymer P(GMA-r-MMA) obtained by traditional radical polymerization of glycidyl methacrylate (GMA) monomer and methacrylic acid (MMA) monomer, and pentafluoropropionic acid (PFPA) is used to modify polymer P(GMA-r-MMA) to obtain fluorine-containing epoxy polymer P(GMA-r-MMA)-g-PFPA. Secondly, fluorine-containing epoxy polymer P(GMA-r-MMA)-g-PFPA and amino-modified nano SiO2 is blended, and the cotton fabric is dip-coated to obtain a superhydrophobic surface, thereby preparing an oil–water separation membrane. By controlling the solution concentration, dipping time, drying time and other conditions, the superhydrophobic performance of the separation membrane was characterized, and the best construction conditions for the superhydrophobic surface were obtained: 0.3 mg mL−1 polymer concentration, immersion time 6 h, drying temperature 120°, and drying time 4 h, and the maximum water contact angle can reach to 150° ± 2°. Finally, the cotton fabric was modified under the best dipping conditions, and used as an oil–water separation membrane to study the oil–water separation performance of n-hexane, n-octane, kerosene, chloroform and water mixtures in batch operation and continuous operation. In batch operations, the separation efficiency can reach 99% and can achieve 5 consecutive high-efficiency separations without intermittent drying. In continuous flow operation, oil–water separation can last for more than 12 hours and the separation efficiency can reach 98%. It also has stable oil–water separation performance for oil–water emulsion.

Extraction Solvents Composition Effect In Biodiesel Production From Microalgae Consortium Botryococcus Braunii And Dunaliella Sp.

Indonesia has entered an energy emergency phase, proven that Indonesia is no longer a surplus oil producer due to the productivity of the wells decrease over the years and the pattern of people's consumption of fossil fuels has been exceeding the production capacity. Therefore, we need the right solution to overcome this problem, which is developing biodiesel as renewable energy based on microalgae oil. The microalgae used in this research is the consortium of microalgae Botryococcus braunii and Dunaliella sp. Microalgae were cultivated and harvested through the dewatering process with 1 g naoh/1 L water concentration. Water contents of cultivated Botryococcus braunii are 60.2505% while Dunaliella sp. Is 64.5002%. The oil from microalgae is obtained by extracted dry microalgae through the soxhlet extraction (leaching) method with mixed solvent n-hexane and ethanol as the co-solvent using a variety of solvent ratio 2:1 and 3:1. Pure microalgae consortium oil separated from the solvent using the distillation process then analyzed with GC-FID. The analysis result is trans-linoleic acid is the most dominant fatty acid contained in this oil. Transesterification process with cao (1.5% of oil weight) as a catalyst. The results obtained from this study are the oil yield 72% extracted with a solvent mixture of n-hexane and ethanol 2:1 and 60.4% for 3:1. The biodiesel synthesis resulted in the amount of yield obtained from the solvent ratio 2:1 extraction is 94.3%, while with solvent ratio 3:1 is 79.2%. The quality of both biodiesels has met the requirements of SNI 7182:2015 and ASTM D7467, except the density of biodiesel with extraction solvent composition 3:1 which is below the standard. Therefore, the best biodiesel quality is obtained from microalgae consortium’s oil with the composition of extraction solvent 2:1.

Experimental study of PVT and phase-transition properties of binary water+n-hexane mixture near the upper critical endpoint

The PρT and phase transition (LLV and LV) properties (PS,TS,ρS) of binary water+n-hexane mixture with fixed concentration of 0.5 mol fraction of n-hexane (equimolar mixture) were measured. Measurements were focused in the immediate vicinity of the upper critical endpoint (UCEP) and supercritical regions in order to closely study the features of the mixture critical behavior near the UCEP. Measurements were made along 15 liquid and vapor isochores between (63.16 and 554.41) kg·m−3 and over a temperature range from (373.15 to 673.15) K at pressures up to 53.3 MPa. Phase transition phenomena on isochoric heating of the binary mixture was detailed study. For each isochore most measurements were made in the immediate vicinity of the LLV and LV phase transition temperatures (in the single-, two-, and three-phase regions) where the break of the P-T isochore's slopes are observing. Temperatures and pressures (PS,TS) at the LLV and LV phase transition points for each fixed density (isochore, ρ) were measured using the isochoric P-T break-point technique in the immediate vicinity of the UCEP of the mixture. The UCEP property data TUCEP = 469.15 K, PUCEP = 5.229 MPa, and ρUCEP = 263.95 kg·m−3 for the binary H2O + n-hexane mixture (x = 0.5 mol fraction of n-hexane) were extracted from the detailed PρT and three-phase equilibrium data (PLLV, TLLV, ρLLV) measurements near the UCEP. The combined expanded uncertainty of the density, ρ, pressure, P, temperature, T, and concentration, x, measurements at the 95% confidence level with a coverage factor of k = 2 is estimated to be 0.2% (density in the liquid phase), 0.3% (density in the gas phase), 0.5% (density in the critical and supercritical regions); 0.05% (pressure); 15 mK (temperature); and 0.01 mol% (concentration). The excess molar volumes (VmE) of the binary mixture were calculated using the measured molar volumes Vm of the mixture and the reference molar volumes of the pure components (water and n-hexane) for various experimental temperatures and pressures in the supercritical region. Also, the measured PρT data at low densities (vapor phase) and high temperatures were used to calculated the second, third, and cross-term virial coefficients of the mixture.

Liquid-liquid equilibrium for n-hexane + benzene + sulfolane, + 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]), + 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) and + the mixtures of [EMIM][NTf2] and [EMIM][EtSO4

The liquid-liquid equilibrium (LLE) data for three ternary mixtures of n-hexane + benzene + sulfolane, + 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) and + 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) and two quaternary ones of n-hexane + benzene + mixed ionic liquids respectively with fixed molar ratio 9:1 and 1:9 of [EMIM][NTf2] to [EMIM][EtSO4] were determined experimentally at (303.15, 313.15 and 323.15) K and atmospheric pressure. The experimental results showed that the ionic liquid of [EMIM][NTf2] captures higher molar distribution coefficient while one of [EMIM][EtSO4] is characterized with higher molar selectivity, compared to the sulfolane solvent that is extensively used for aromatic extraction in industry. The improvement of the composite separation performance for n-hexane and benzene was observed through mixing the above two ionic liquids. To represent the experimental diagram, the activity coefficient model of Non-Random Two-Liquid (NRTL) was employed to correlate the experimental data and good agreements between theoretical and experimental results were obtained. In general, the selected ionic liquid and its mixture in this work could be considered as a potential substitute for sulfolane.