Vacuum Fractional Distillation Research Articles

Development of a bi-solvent liquid scintillator with slow light emission

One of the most promising approaches for the next generation of neutrino experiments is the realization of large hybrid Cherenkov/scintillation detectors made possible by recent innovations in photodetection technology and liquid scintillator chemistry. The development of a potentially suitable future detector liquid with particularly slow light emission is discussed in the present publication. This cocktail is compared with respect to its fundamental characteristics (scintillation efficiency, transparency, and time profile of light emission) with liquid scintillators currently used in large-scale neutrino detectors. In addition, the optimization of the admixture of wavelength shifters for a scintillator with particularly high light emission is presented. Furthermore, the pulse-shape discrimination capabilities of the novel medium was studied using a pulsed particle accelerator driven neutron source. Beyond that, purification methods based on column chromatography and fractional vacuum distillation for the co-solvent DIN (Diisopropylnaphthalene) are discussed.

Vacuum fractional distillation of Cunila galioides Benth. essential oil: chemical composition and biological activities of raw oil and its fractions

This work aimed to rectify Cunila galioides essential oil and evaluate the raw oil and the fractions’ antifungal, allelopathic, and antioxidant activities. The results showed that the raw essential oil and the bottom fraction were primarily composed of linalyl propionate (42.9 wt.% and 60.2 wt.%). The top fraction was composed mainly of limonene (45.7 wt.%). The antioxidant activity changed with the radical and the fraction. The bottom had a weaker antifungal effect than the raw oil and the top. Nevertheless, the essential oil and the fractions had a similar antifungal activity at 0.50 % v/v and higher. Similar behavior was observed for the allelopathic tests. No difference occurred between the raw oil and the fractions, with reduced germination percentages and speed at 0.25 % v/v and complete inhibition at 0.50 % v/v. The oil can be rectified, and the fractions may be used without harming their biological activity.

Inhibitory activities of essential oils from Syzygium aromaticum inhibition of Echinochloa crus-galli.

Echinochloa crus-galli is a serious weed species in rice paddies. To obtain a new potential bioherbicide, we evaluated the inhibitory activities of 13 essential oils and their active substances against E. crus-galli. Essential oil from Syzygium aromaticum (L.) Merr. & L. M. Perry (SAEO) exhibited the highest herbicidal activity (EC50 = 3.87 mg mL-1) among the 13 essential oils evaluated. The SAEO was isolated at six different temperatures by vacuum fractional distillation, including 164°C, 165°C (SAEO-165), 169°C, 170°C 175°C and 180°C. The SAEO-165 had the highest inhibitory rate against E. crus-galli. Gas chromatography-mass spectrometry and high phase liquid chromatography identified eugenol (EC50 = 4.07 mg mL-1), α-caryophyllene (EC50 = 17.34 mg mL-1) and β-caryophyllene (EC50 = 96.66 mg mL-1) as the three compounds in SAEO. Results from a safety bioassay showed that the tolerance of rice seedling (~ 20% inhibition) was higher than that of E. crus-galli (~ 70% inhibition) under SAEO stress. SAEO induced excessive generation of reactive oxygen species leading to oxidative stress and ultimately tissue damage in E. crus-galli. Our results indicate that SAEO has a potential for development into a new selective bio-herbicide. They also provide an example of a sustainable management strategy for E. crus-galli in rice paddies.

Isolation of citronellal and geraniol from citronella (Cymbopogon winterianus) oil by vacuum fractional distillation: Effect of operating conditions on the separation

Abstract This study used fractional distillation to separate citronellal and geraniol from citronella (Cymbopogon winterianus) essential oil to improve their market value. The one-factor-at-a-time methodology investigated operating parameters’ optimum conditions and effects, including system pressure, packing types, and column height. All investigations were evaluated based on their main fraction’s citronellal and geraniol content and recovery. Regarding the effect of the variables, a higher system pressure improved the separation while increasing the temperature range of each fraction and distillation time. The packing types would also improve the separation by providing a large surface area. Finally, the column height also positively impacted the separation. In the optimum citronella oil fractionation, citronellal content experienced a 2.5-fold increase, from 37.68% to 94.33%. Geraniol purity reached 40.61% from an initial content of 17.33% in the raw CW oil. The distillation could recover up to 90.00% of citronellal and 68.18% of geraniol.

Impact of fractional distillation on physicochemical and biological properties of oregano essential oil of Lippia graveolens H.B.K. grown wild in Mexico

The aim of this work was to evaluate the impact of fractional distillation on the physicochemical and biological properties of oregano essential oil obtained from Lippia graveolens H.B.K. Dry vacuum fractional distillation allowed the division of oregano essential oil into two distinct fractions. The first fraction was rich in ρ-cymene (45.32%) and γ-terpinene (19.14%), while the second fraction had enrichments on the phenolic thymol and carvacrol components (47.63% and 35.56%, respectively), reaching up to 83% of the total chemical composition. In addition, it was shown that fractionation influenced the biological properties of the essential oil. The fraction enriched on thymol and carvacrol showed a higher antioxidant activity than the complete oregano essential oil and the terpenic fraction, as measured by the DPPH method. Moreover, the phenolic fraction produced a concentration-dependent viability decrease on HeLa, Hep2 and A-549 cancer cell lines. The cytotoxic activity of the phenolic fraction was higher compared to that of complete oregano essential oil as well as that of the terpenic fraction. It can be concluded that dry vacuum fractional distillation is an effective separation method that could be used to rectify and improve the quality of oregano essential oils, making them more attractive in the market. As another benefit, the fractions generated could be used for different purposes. In practice, the terpenic fraction, for example, could be used in flavouring and fragrance industries. Regarding the phenolic fraction, new and deeper studies are needed to establish its potential use in food safety and pharmaceutical industries.

Optimization of the Vacuum Fractional Distillation Process for Enhancing the α-Guaiene of Patchouli Oil with Response Surface Methodology

α-guaiene is one of the primary sesquiterpene compounds used as a flavor and fragrance agent in patchouli oil. The fraction of patchouli oil that is rich in α-guaiene has been successfully isolated. In the present work, α-guaiene was isolated from crude patchouli oil through vacuum fractional distillation followed by GC-MS identification. Three important process parameters—feed volume, reflux ratio, and applied run pressure—were investigated and optimized using Box–Behnken design. The research methodology was an experimental laboratory using response surface methodology (RSM) with a feed volume level from 75 mL to 125 mL, a reflux ratio from 10:1 to 30:1, and an applied run pressure from 5 mmHg to 15 mmHg. The α-guaiene-enriched fraction was found in the first distillate fraction patchouli. The optimum condition that generated α-guaiene fraction at 44.70% purity was the treatment with a feed volume of 75 mL, a reflux ratio of 24:1, and applied run pressure of 14.80 mmHg. Results indicated that feed volume did not significantly affect the α-guaiene content, while the applied run pressure and reflux ratio used had a significant effect. A quadratic mathematical model with R2 0.861 and validation 96.14% was suitable for predicting the optimum α-guaiene fraction content during the vacuum fractional distillation process.

Citral enrichment in Lemongrass (Cymbopogon flexuosus) oil using spinning band equipped high vacuum distillation column and sensory evaluation of fractions

Citral is the major constituent of Lemongrass oil (LGO) and has various application in the food, cosmetic and pharmaceutical industry. The present study was focused on enhancement of citral content in LGO employing spinning band column equipped high vacuum fractional distillation setup. The collected fractions were investigated for volatile composition using gas chromatography-mass spectrometry (GC–MS), antioxidant activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and antibacterial activity against Gram-positive and Gram-negative bacteria. The total citral content varied from 1.90 to 88% in various fractions with highest in major fraction, residue experiment-B (RSD, Ex-B, 88%) with collection of 63 mL. RSD, Ex-B demonstrated the lowest IC50 value of 6.77±0.42µL/mL with 55.84 percent inhibition. Further, strong inhibition was demonstrated by RSD, Ex-B against all tested bacterial strains. The sensory analysis revealed that Lemongrass leaves were dominated with lemony, fresh and grassy; LGO with lemony and fresh; and RSD (Ex-B) with lemony, sweet and fresh notes. The distillation process changed the overall aroma profile of RSD (Ex-B) by eliminating grassy and off odors and makes it useful product for flavor and fragrance application. Citral rich fractions have high economic value as well as application in food industry as a flavor, preservative; in home care and self-hygiene products.

Vacuum fractional distillation of biocrude oil and the immobilization of harmful metal

• Fractional distillation can obviously decrease the O and S content in biocrude. • The majority of the alkali/heavy metals migrated to distillation residue. • Over 35.0% of the As in raw biocrude oil lead to distillation oil. • In-situ catalytic reaction of CaCO 3 /K 2 CO 3 promotes the denitrification process. The high heteroatom and excessive metals induce poor physiochemical properties of algae-biocrude, causing either damage to engine or air pollution. This study systematically investigated elements migration behaviors during vacuum fractional distillation of raw biocrude. Comparing with the raw biocrude, the oxygen (O) and sulfur (S) content in the distillates was greatly decreased by 47.6% and 44.3%, respectively. Over 96.0% of the Ca, K, and Pb in the raw biocrude concentrated into the distillation residue. Notably, the migration morphology of As is very special with only 63.1% of the As migrated into the residue associated with organic As in biocrude. In-situ catalytic reaction of CaCO 3 /K 2 CO 3 may promote the metal migration, denitrogenation, and desulfurization process. The distillate oil obtained at 275 °C (F6) has the highest abundant of saturated hydrocarbon (62.69%) with relatively high H/C and low N/C among all the distillates, which was probably an excellent transport alternative biofuel.

Improvement of the Crude Glycerol Purification Process Derived from Biodiesel Production Waste Sources through Computational Modeling

Considering waste as a possible new resource for useful purposes is one of the strategies included in the circular economy principles. In fact, industrial processes are seen as great contributors to the formation of waste streams. With the aim to attain more sustainable and resilient systems, in this study, a process flow chart was elaborated in an Aspen Plus computer simulator, to obtain the production of pure glycerol from crude glycerol (a by-product of biodiesel production). This process occurs through fractional vacuum distillation, the methanol recovery route in the deacidification process and the removal of methanol from the reaction medium. The separation stages of the crude glycerol implemented enabled a degree of purification of 99.77%, meeting the specifications of the pharmaceutical use. The developed model allowed for the optimization of the purification process, raising by 40% the mass flow rate of pure glycerol. A conclusion could be drawn that the use of crude glycerol is an excellent option for the development of new products with greater added-value, contributing to the zero waste principles and to the circular economy.

Enriching terpinen-4-ol from tea tree (Melaleuca alternifolia) oil using vacuum fractional distillation: Effect of column and packings on the separation

Two types of columns, three types of packings, and four levels of column height were considered to investigate how column and packings affected the separation in the vacuum fractional distillation process of raw tea tree (Melaleuca alternifolia) oil (TTO). This study discussed those effects on purity, yield, and overall discovery to select the most excellent operating conditions for enriching terpinen-4-ol. After the experiments, the essential oil was successfully separated into two fractions, in which the second one composed mostly the main TTO constituent, terpinen-4-ol. The best result was achieved by conducting the distillation on a 300-mm Hempel column filled with small Fenske helices (10 mm × 2 mm i.d.) at the system pressure of 60 mmHg. GC/MS analysis showed an almost 2.5-fold increase in the content of terpinen-4-ol, from 39.23% to 95.77% after fractionation. Meanwhile, there was 75% of terpinen-4-ol successfully recovered from its parental oil. Hence, the vacuum fraction distillation could be an effective method to enrich the terpinen-4-ol content in TTO.

Seasonal Variation, Fractional Isolation and Nanoencapsulation of Antioxidant Compounds of Indian Blackberry (Syzygium cumini).

Indian blackberry (Syzygium cumini L.) is an evergreen tree in the Myrtaceae family. It is used in traditional medicine due to its significant bioactivities and presence of polyphenols with antioxidant activities. The present study describes the effect of seasonal variations on Indian blackberry leaf essential oil yield and chemical composition, production of fractions from essential oil using high vacuum fractional distillation and slow cooling to low temperature (−50 °C) under vacuum, and bioactivities of the essential oil, fractions, and nanoparticles. The results show that Indian blackberry essential oil yield was higher in spring season as compared to winter season. Indian blackberry essential oil fractionation processes were effective in separating and concentrating compounds with desired bioactivities. The bioactivities shown by magnesium nanoparticles were comparatively higher than barium nanoparticles.

A Novel Heterogeneous Superoxide Support-Coated Catalyst for Production of Biodiesel from Roasted and Unroasted Sinapis arvensis Seed Oil

Disadvantages of biodiesel include consumption of edible oils for fuel production, generation of wastewater and inability to recycle catalysts during homogenously catalyzed transesterification. The aim of the current study was to utilize low-cost, inedible oil extracted from Sinapis arvensis seeds to produce biodiesel using a novel nano-composite superoxide heterogeneous catalyst. Sodium superoxide (NaO2) was synthesized by reaction of sodium nitrate with hydrogen peroxide via spray pyrolysis, followed by coating onto a composite support material prepared from silicon dioxide, potassium ferricyanide and granite. The roasted (110 °C, 20 min) and unroasted S. arvensis seeds were subjected to high vacuum fractional distillation to afford fractions (F1, F2 and F3) that correlated to molecular weight. For example, F1 was enriched in palmitic acid (76–79%), F2 was enriched in oleic acid (69%) and F3 was enriched in erucic acid (61%). These fractions, as well as pure unroasted and roasted S. arvensis seed oils, were then transesterified using NaO2/SiO2/PFC/Granite to give biodiesel a maximum yield of 98.4% and 99.2%, respectively. In contrast, yields using immobilized lipase catalyst were considerably lower (78–85%). Fuel properties such as acid value, cetane number, density, iodine value, pour point, and saponification value were within the ranges specified in the American biodiesel standard, ASTM D6751, where applicable. These results indicated that the nano-composite catalyst was excellent for production of biodiesel from unroasted and roasted S. arvensis seed oil and its fractions.

Production and Evaluation of Fractionated Tamarind Seed Oil Methyl Esters as a New Source of Biodiesel

Biodiesel has attracted considerable interest as an alternative biofuel due to its many advantages over conventional petroleum diesel such as inherent lubricity, low toxicity, renewable raw materials, biodegradability, superior flash point, and low carbon footprint. However, high production costs, poor low temperature operability, variability of fuel quality from different feedstocks, and low storage stability negatively impact more widespread adoption. In order to reduce production costs, inexpensive inedible oilseed alternatives are needed for biodiesel production. This study utilized inedible tamarind (Tamarind indica) seed oil as an alternative biodiesel feedstock, which contained linoleic (31.8%), oleic (17.1%), and lauric (12.0%) acids as the primary fatty acids. A simple and cost-effective high vacuum fractional distillation (HVFD) methodology was used to separate the oil into three fractions (F1, F2, and F3). Subsequent transesterification utilizing basic, acidic, and enzymatic catalysis produced biodiesel of consistent quality and overcame the problem of low temperature biodiesel performance. The most desirable biodiesel with regard to low temperature operability was produced from fractions F2 and F3, which were enriched in unsaturated fatty acids relative to tamarind seed oil. Other properties such as density and cetane number were within the limits specified in the American and European biodiesel standards.

Evaluation of antibacterial properties of some essential oils from Vietnam

Natural products have attracted attention from scientists because of their potential to replace antibiotics in the near future. Thanks to Vietnam’s richness in biodiversity, this study aimed at evaluating antibacterial activity of eleven essential oils from various plants. These essential oils were collected from various plants across Vietnam such as corn mint, clove, clove basil, eugenol, tea tree, terpinen-4-ol, kaffir lime, Mexican mint, rosemary, Homalomena occulta, and betel. By chemical reaction and fractional vacuum distillation method, eugenol and terpinen-4-ol was isolated from clove basil and tea tree oils with the content reaching up to 97.0% and 95.8%, respectively. The antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli of essential oils was determined by disk diffusion and broth dilution method. As a result, Mexican mint oil and eugenol exhibited high antibacterial properties with low MICs and MBCs (62.5 to 125 uL/L), whereas other essential oils (clove, clove basil, betel, tea tree, terpinen-4-ol) had higher MIC and MBC values ranged from 125 to 500 uL/L.

Coal tar waste utilization by cracking into fuel source and its separation using the fractional vacuum distillation method

Coal tar is a hazardous and toxic waste, a by-product of coal gasification processes. Coal tar is a waste produced in industrial fields such as steel, power plant, and the cement industry. As a potential fuel source for its component, utilization of coal tar by catalytic cracking into fuel source and its separation using fractional vacuum distillation is conducted. Pyrolysis of low-temperature coal tar (LTCT) was carried out using catalyst activated natural zeolite by 2:10 ratio at various temperature. The middle oil (180-260°C) fraction was distilled through fractional vacuum distillation using Vigroux column fraction and analyzed using gas chromatography-mass spectroscopy (GC-MS). In this study, the rate constant (k) of middle oil recovery was increased with the increase of temperature and reduced pressure. The calorific value, the density, the kinematic viscosity, the flashpoint, the pour point, and the sulfur content of the middle oil complied with diesel oil type 2 specifications. Still, it did not meet the specification for density specifications. The main components of the middle oil fraction were naphthalenes and their derivatives. The results indicated that the raw LTCT could be considerably upgraded through catalytic cracking, obtaining fuel oil fraction.

Chemical Composition and Antibacterial and Antioxidant Activity of a Citrus Essential Oil and Its Fractions.

Essential oils (EOs) from Citrus are the main by-product of Citrus-processing industries. In addition to food/beverage and cosmetic applications, citrus EOs could also potentially be used as an alternative to antibiotics in food-producing animals. A commercial citrus EO—Brazilian Orange Terpenes (BOT)—was fractionated by vacuum fractional distillation to separate BOT into various fractions: F1, F2, F3, and F4. Next, the chemical composition and biological activities of BOT and its fractions were characterized. Results showed the three first fractions had a high relative amount of limonene (≥10.86), even higher than the whole BOT. Conversely, F4 presented a larger relative amount of BOT’s minor compounds (carvone, cis-carveol, trans-carveol, cis-p-Mentha-2,8-dien-1-ol, and trans-p-Mentha-2,8-dien-1-ol) and a very low relative amount of limonene (0.08–0.13). Antibacterial activity results showed F4 was the only fraction exhibiting this activity, which was selective and higher activity on a pathogenic bacterium (E. coli) than on a beneficial bacterium (Lactobacillus sp.). However, F4 activity was lower than BOT. Similarly, F4 displayed the highest antioxidant activity among fractions (equivalent to BOT). These results indicated that probably those minor compounds that detected in F4 would be more involved in conferring the biological activities for this fraction and consequently for the whole BOT, instead of the major compound, limonene, playing this role exclusively.

Fractionating of Lemongrass (Cymbopogon citratus) Essential Oil by Vacuum Fractional Distillation

Lemongrass essential oil has many compounds appropriate for application in foods, cosmetics, and pharmaceutical products. Of these, citral is a high-value compound of interest to industry. This work aims to evaluate the use of vacuum fractional distillation to separate lemongrass essential oil compounds, producing essential oil fractions containing high citral content. The effect of process parameters, namely vacuum pressure, type column, and energy input, on the fractionation time, content, and recovery of citral in the fractions, was investigated. The fractionation of lemongrass oils successfully provided five fractions, i.e., fraction 1 (F1), fraction 2 (F2), fraction 3 (F3), fraction 4 (F4), and fraction 5 (F5). GC-MS (Gas Chromatography-Mass Spectrometry) spectra showed that the main compound contained in F1 and F2 fractions was β-myrcene (>70%). Meanwhile, F4 and F5 were the two main fractions for citral recovery. The optimal conditions of the fractional distillation system included a column height of 400 mm, power input of 165 W, and pressure of 15 mmHg. These conditions correspond to the highest total citral content of 95%, with a recovery of 80% at the F4 and F5 fractions. Therefore, fractional vacuum distillation may be an effective method to upgrade lemongrass essential oil.

Techno‐Economic Evaluation of d‐Limonene and α‐Pinene Separation from Citrus and Turpentine Oils

AbstractThe evaluation of the technical and economic separation of the monoterpenes α‐pinene and d‐limonene from essential oils, carried out by computational simulation of the vacuum fractional distillation in continuous and batch mode from samples of turpentine and citrus oils, was developed using Aspen Plus® software combined with estimations of operational expenses (OPEX) and capital expenses (CAPEX) based on the Guthrie method. The production of d‐limonene and α‐pinene with high purity from the essential oils is a technically feasible process. From the economic point of view and based on the average annual import costs of turpentine and orange oils in Colombia, it was found that the selling prices of α‐pinene and d‐limonene obtained from the distillation module cost analysis depend on the daily production and can be minimized if essential oils are preliminary extracted from local industrial wastes.

Isolation and gas chromatographic method for determination of osthole from Cnidii Fructus

The purpose of this research is to study the isolation and purification of osthole from Cnidii Fructus extract and to establish a gas chromatographic method for determining the osthole content from various Cnidii Fructus samples. Six solvents were used to extract Cnidii Fructus in order to evaluate their efficiency in extracting osthole. Vacuum fractional distillation and traditional column chromatography were compared to evaluate the efficiency in purifying osthole from Cnidii Fructus extract. Gas chromatographic method was used to determine osthole content in Cnidii Fructus extract. The analytical conditions are the following: nitrogen as the carrier gas, the flow rate of 40 mL/min; the split ratio of 120: 1. The column used was DB™-5 (30 m × 0.53 mm I.D., 1.5 μm) equipped with a flame ionization detector (FID). The initial oven temperature was programmed to be at 135°C for 12 minutes. The temperature was then raised to 215°C at a rate of 12°C /min for 20 minutes. The retention time of osthole was 24.1 min. Caffeine anhydrous was used as the internal standard with a retention time of 18.9 minutes. A comparative evaluation showed that aqueous alcoholic solvent was the most efficient solvent among six used in extraction of osthole from a Cnidii Fructus. Vacuum fractional distillation is useful for purifying osthole from Cnidii Fructus extract. It was found that the osthole content of commercial Cnidii Fructus samples varied from 0.05% to 2.14%. And the osthole content of Cnidii Fructus samples collected from Southern China was higher than those collected from Northern China.

High Vacuum Fractional Distillation (HVFD) Approach for Quality and Performance Improvement of Azadirachta indica Biodiesel

Biodiesel offers an advantage only if it can be used as a direct replacement for ordinary diesel. There are many reasons to promote biodiesel. However, biodiesel cannot get wide acceptance until its drawbacks have been overcome including poor low temperature flow properties, variation in the quality of biodiesel produced from different feedstocks and fuel filter blocking. In the present study, a much cheaper and simpler method called high vacuum fractional distillation (HVFD) has been used as an alternative to produce high-quality refined biodiesel and to improve on the abovementioned drawbacks of biodiesel. The results of the present study showed that none of biodiesel sample produced from crude Azadirachta indica (neem) oil met standard biodiesel cetane number requirements. The high vacuum fractional distillation (HVFD) process improved the cetane number of produced biodiesels which ranged from 44–87.3. Similarly, biodiesel produced from fractionated Azadirachta indica oil has shown lower iodine values (91.2) and much better cloud (−2.6 °C) and pour point (−4.9 °C) than pure Azadirachta indica oil. In conclusion, the crude oil needs to be vacuum fractioned for superior biodiesel production for direct utilization in engine and consistent quality production.