首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
An aqueous extraction process (AEP) was developed for dehulled yellow mustard flour with the aim of producing yellow mustard oil for industrial applications, as a by-product of food protein production. During AEP, most of the oil extracted was bound in a stable oil-in-water emulsion that must be destabilized to recover free oil. The oil distribution after aqueous extraction and the composition of the emulsion produced were determined. The emulsion was solubilized in organic solvents including tetrahydrofuran (THF) and 1,4-dioxane to fully recover the oil in a single-phase oil–solvent-water miscella. Over 97 and 95% of the oil in the emulsion was successfully recovered using 4:1 THF:oil and 9:1 dioxane:oil weight ratios, respectively. The oil recovery from the emulsion was optimized, based on experimentally prepared ternary phase diagrams of THF/oil/water and dioxane/oil/water. The results suggest that this technically viable approach can successfully recover essentially all of the oil from the emulsion, equivalent to an overall free oil recovery of ~63% from dehulled yellow mustard flour.  相似文献   

2.
An aqueous extraction process was developed consisting of aqueous contact with dehulled yellow mustard flour to recover protein followed by dissolution of the released emulsion in dimethylformamide (DMF) or isopropyl alcohol (IPA) to recover the released oil in the form of single-phase oil–solvent miscellae suitable for industrial applications. Only some 38 ± 3 % of the oil in the yellow mustard emulsion was extracted using DMF even at high weight ratios since DMF is widely miscible with water, preventing separation of the oil from the emulsion. A ternary phase diagram of DMF/oil/water was prepared and confirmed the limited solubility of the oil in DMF in the presence of water. The use of 31:1 IPA:oil weight ratio could effectively recover over 94 % of the oil in the emulsion; however, multiple-stage treatment of the emulsion was proven to be more efficient with lower volumes of IPA required to achieve high oil extraction yields. The results suggest that the optimal conditions for multiple-stage process were four stages using 2:1 IPA:oil weight ratio, with 96 ± 1 % oil recovery from the emulsion.  相似文献   

3.
Tetrahydrofuran, added to the oil‐in‐water emulsions formed by the aqueous processing of yellow mustard flour, produced oil/water/THF miscellas containing 1–2 % water. The high water content prevented the direct conversion of the system to fatty acid methyl esters (FAME) through a single‐phase base‐catalyzed transmethylation process. Dehydration of these miscellas by adsorption on 4A molecular sieves at room temperature using either batch or continuous fixed‐bed systems successfully reduced the water content to the quality standards needed for biodiesel feedstock (0.3 %). Equilibrium adsorption studies for the uptake of water from oil/THF/water miscella phases at room temperature allowed quantitative comparison of the water adsorption capacity based on the oil and THF concentrations of the miscellas. Batch contact was used to investigate the dominant parameters affecting the uptake of water including miscella composition, adsorbent dose and contact time. The adsorption of the water was strongly dependent on adsorbent dose and miscella oil concentrations. The regeneration of molecular sieves by heating under nitrogen at reduced pressure for 6 h at 275 °C resulted in incomplete desorption of miscella components. The adsorption breakthrough curves in terms of flow rates, initial water and oil miscella concentrations were determined. The dehydrated miscella phases were reacted with methanol in a single‐phase base‐catalyzed transmethylation process with high yields (99.3 wt%) to FAME. The resulting FAME met the ASTM international standard in terms of total glycerol content and acid number.  相似文献   

4.
Using an isopropyl alcohol (IPA):flour [volume:weight (ml:g)] ratio of 1.5:1 per stage of extraction resulted in an oil yield of 86.3%. The combined miscella (IPA + oil), which contained 90.6 wt% IPA, 9.8 wt% oil, and 2.1 wt% water, was used as a feedstock for biodiesel production by transesterification. Transesterification of the IPA/oil miscella dehydrated using adsorption on 4Å molecular sieves with 1.2 wt% (based on oil) potassium hydroxide for 2 h at 72 °C converted only 29% of the feed to esters. The addition of methanol (MeOH) resulted in an ester yield of 87%, consisting of 79% methyl ester and 7% isopropyl ester when starting with an IPA:oil:MeOH molar ratio of 146:1:30. By increasing the KOH catalyst to 3 wt%, the ester yield increased to 94%. To increase the ester yield, the miscella was pretreated with sulfuric acid. This resulted in a reduction of the IPA content, the removal of other impurities such as phospholipids, and reduction of the water mass fraction to less than 1%. When IPA was used as a cosolvent with methanol in the transesterification process, a very high ester conversion (>99%) was achieved. The biodiesel produced was compliant with ASTM standards, showing that IPA can be used as a solvent for oil extraction from yellow mustard flour.  相似文献   

5.
The recovery of solvents used during biodiesel synthesis is an important factor in the economic feasibility and sustainability of the entire process. In this study, we looked at the use of isopropyl alcohol (IPA) for oil extraction and biodiesel production, as well as its potential for recovery and recycling. We found that multistage extraction improved oil recovery, with up to 86% oil yield using four stages of extraction at an IPA:mustard flour (volume:weight) ratio of 1.5:1 at room temperature. Using acid–base‐catalyzed transesterification, 99% of the mustard oil was converted to biodiesel. At the end of this process, IPA was recovered from the azeotrope by salting out using potassium carbonate or sodium carbonate. The solubility behavior of the components was evaluated by means of ternary‐phase diagrams of IPA/water/sodium carbonate and IPA/water/potassium carbonate, which determined their liquid–liquid–solid equilibrium constants at ambient pressure and at room temperature. Using 20% (w:w) potassium carbonate, 95% of the IPA was recovered at 99% purity from a starting mixture of IPA containing 13% water. Azeotropic distillation of the IPA–water azeotrope with 10% potassium carbonate resulted in the recovery of 99% of the IPA at 94% purity. These results suggest that IPA is not only a suitable solvent for mustard‐oil extraction but also for salt‐enhanced azeotropic distillation resulting in near‐complete recovery from aqueous solutions.  相似文献   

6.
The oil-in-water emulsion formed during an aqueous extraction of yellow mustard seed flour was destabilized using isopropyl alcohol (IPA) in a four stage extraction process, with concurrent recovery of oil and water in separate phases. The emulsion was extracted using two different approaches: phase separation extraction (PSE) that used fresh IPA as the extraction solvent at each stage, and phase separation extraction with recycle (PSER) that reused the extracted water-rich phase, containing IPA, as the extraction solvent. Extraction processes by both approaches were modeled by the ternary liquid phase diagram of IPA, canola oil and water to characterize the extraction progress. PSER resulted in improved oil–water separation and IPA usage efficiency than PSE, but achieved only 84.0?% oil recovery, compared to 92.3?% by PSE. The ternary diagram of IPA, canola oil and water offered good approximation of the oil and water separation behavior of PSE and PSER by closely predicting the compositions of the separated phases; however, the weight ratio of the separated phases were not as closely predicted.  相似文献   

7.
Dry emulsions are powdery, lipid-based formulations from which an o/w-emulsion can be easily reconstituted in vivo or when exposed to water. The objective of this work was to prepare and characterize dry emulsion of itraconazole (ITZ) to improve its solubility and bioavailability. Dry emulsions were prepared by spray-drying liquid o/w-emulsions containing carriers like maltodextrin, sucrose, and lactose. Propylene glycol monocaprylate was selected as oil phase, and surfactant blends of vitamin E tocopherol polyethylene glycol succinate and triblock PEO–PPO–PEO copolymer as emulsifying agents. Several oil:water and carrier:water ratios were tested. An optimum formulation was selected using 32 full factorial design. The droplet size, rheological behavior, and drug release from o/w-emulsion before and after reconstitution and the micromeritic properties of spray-dried product were investigated. Maltodextrin was used as a carrier for preparing dry emulsions. The optimized dry emulsion was characterized using DSC, SEM, PXRD, and in vivo study. The SEM analysis showed that dry emulsion consisted of well-separated particles with smooth surfaces. The DSC and XRD study showed that ITZ in the dry emulsion is in the molecular dispersion state. Globule size analysis showed that dry emulsion had good reconstitution properties. The emulsions were found to be thermodynamically stable when subjected to cyclical freeze–thaw cycles and centrifugation tests. The average globule size of emulsions ranged from 0.994 to 1.668 μm. A 71.35 % increase in C max and 114.78 % increase in AUC was evident for ITZ dry emulsion as compared to plain ITZ.  相似文献   

8.
《分离科学与技术》2012,47(6):1367-1377
Abstract

The demulsifying and separating experiments of crude oil emulsion were performed by using the heating method, the thermal chemical method, the microwave radiating method, and the microwave chemical method separately. The water content of this emulsion was 78 v/v%, and the type was water‐in‐oil (w/o). The influence tendencies of the key factors on demulsification effect were explored by changing the heating temperature, the demulsifier amount used and the microwave radiating time in this paper. With the microwave chemical experiments on the self‐made emulsions of different water content, the demulsification rate and separation efficiency were explored. The type of these emulsions were oil‐in‐water (o/w), water‐in‐oil (w/o) and the multiple type, related to the water content scopes which were less than 30 v/v%, more than 70 v/v% and between them, respectively. The separation effect by the microwave chemical method for the high water content crude oil emulsion was better than that of emulsion with lower water content. For the crude oil used in this experiment, the result could be obtained that the separation efficiency was about 95 v/v% under the conditions of 50 ppm of demulsifier, 10 seconds radiation time, and 1 minute settling time for the microwave chemical method.  相似文献   

9.
Aqueous surfactant-assisted extraction (ASE) has been proposed as an alternative to n-hexane for extraction of vegetable oil; however, the use of inexpensive surfactants such as sodium dodecyl sulfate (SDS) and the effect of ASE on the quality of biodiesel from the oil are not well understood. Therefore, the effects on total oil extraction efficiency of surfactant concentration, extraction time, oilseed to liquid ratio and other parameters were evaluated using ASE with ground canola and SDS in aqueous solution. The highest total oil extraction efficiency was 80 %, and was achieved using 0.02 M SDS at 20 °C, solid–liquid ratio 1:10 (g:mL), 1,000 rpm stirring speed and 45 min contact time. Applying triple extraction with three stages reduced the amount of SDS solution needed by 50 %. The ASE method was scaled up to extract 300 g of ground canola using the best combination of extraction conditions as described above. The extracted oil from the scale-up of the ASE method passed the recommendation for biodiesel feedstock quality with respect to water content, acid value and phosphorous content. Water content, kinematic viscosity, acid value and oxidative stability index of ASE biodiesel were within the ASTM D6751 biodiesel standards.  相似文献   

10.
Vegetable oils are typically extracted with hexane; however, health and environmental concerns over its use have prompted the search for alternative solvents. Mustard oil was extracted with isopropyl alcohol (IPA) to produce an IPA‐oil miscella suitable for industrial applications. Single‐stage extraction resulted in 87.6 % oil yield at a 10:1 (v/w) IPA/flour ratio. Multiple‐stage extraction resulted in higher extraction efficiency with lower IPA use. Four‐stage cross‐current extraction at an IPA/flour ratio of 2:1 (v/w) per stage resulted in 93.7 % oil yield. At 45 °C, a 91.5 % oil yield was achieved with three‐stage extraction using a 2:1 (v/w) IPA/flour ratio. Any changes to the pH of the mixture resulted in reduced oil yield. Water also reduced the extraction efficiency. The azeotropic IPA solution containing 13 % water extracted ~40 % less oil than did dry IPA in both single and multiple‐stage extractions. Some polar compounds were also extracted, including sugars; however, protein extraction was negligible. The protein left in the extracted meal was not degraded or lost during the extraction. The results suggest that IPA is an excellent solvent for mustard oil, but water content exceeding 5 % in the solvent adversely affects the oil extraction and reuse of the IPA.  相似文献   

11.
Amphiphilic star copolymers were synthesized by sequential monomer and cross-linker additions using group transfer polymerization (GTP). Benzyl methacrylate (BzMA) and methoxy hexa(ethylene glycol) methacrylate (HEGMA) served as the hydrophobic and hydrophilic monomers, respectively, whereas the also hydrophobic ethylene glycol dimethacrylate (EGDMA) was used as the cross-linker. In total, twelve star copolymers were prepared, covering three different overall hydrophobic compositions, 39, 53 and 70% w/w, and four different architectures, AB star-block, BA star-block, heteroarm star and random star. The theoretical molecular weight of each arm was kept constant at 5000 g mol−1. The molecular weights and molecular weight distributions of the linear precursors and of all the star copolymers were characterized by gel permeation chromatography (GPC) in tetrahydrofuran (THF), while their compositions were confirmed by proton nuclear magnetic resonance (1H NMR) spectroscopy. Moreover, all the star copolymers were characterized by static light scattering (SLS) in THF to determine the absolute weight-average molecular weight, Mw, and the weight-average number of arms. After polymer characterization, xylene-water and diazinon (pesticide)-water emulsions were prepared using these star copolymers as stabilizers at 1% w/w copolymer concentration and at different overall organic phase/water ratios. The most important factor in determining the emulsion type was the star copolymer composition in hydrophobic units. The four most hydrophilic star copolymers (39% w/w hydrophobic composition) always formed o/w emulsions, while the four most hydrophobic star copolymers (70% w/w hydrophobic composition) always formed w/o emulsions. The type of the emulsion in the case of the star copolymers with the more balanced composition, 53% w/w hydrophobic units, also depended on the emulsion content in the organic solvent, similar to particulate-stabilized emulsions. Considering that the best o/w emulsifier is that star copolymer which can emulsify the largest quantity of organic phase in water resulting in low viscosity, o/w emulsions without excess oil or water phase, it appeared that the most hydrophilic random copolymer star is the optimal emulsifier. Moreover, this star copolymer presented the smallest droplet size in its emulsions. It is also noteworthy that the resulting emulsions almost never had high viscosity, a feature attributable to the compact nature of star polymers.  相似文献   

12.
A series of alkyl phenol polyoxyethylene glycidyl ether (NP-n-O) and alkyl phenol polyoxyethylene ether hydroxypropyl sulfonate (NP-n-S) surfactants was synthesized to explore emulsification viscosity reduction. The optimum sulfonation conditions were obtained through orthogonal experiments, the ratio of alkyl phenol polyoxyethylene glycidyl ether and sodium bisulfite 1:1.5, 100 °C, and 6 h. The effects of concentrations of the synthesized surfactants, pH values, emulsifying temperature (40 and 60 °C) and water content on emulsification viscosity reduction and the stability of the emulsion to Venezuela’s Orinoco heavy oil were investigated. The water diversion ratio of emulsion at the reservoir temperature (55 °C) in 30 days was taken as an index, the results show that under the conditions of a temperature of 40 °C, an oil/water ratio of 7:3 and a surfactant NP-4-S concentration of 0.5 %, emulsions can be formed with a viscosity reduction rate reaching up to 99.69 % and with a water diversion ratio in 30 days reaching 9.38 %; while at 60 °C and an oil/water ratio of 7:3, at an NP-4-S concentration of 1 %, the viscosity reduction rate can reach 99.55 % and water diversion ratio is merely 4.23 % in 30 days. The mixture of NP-n-S, xanthan gum and cocamidopropyl dimethylamine oxide (CAO-30) at suitable concentration can greatly improve the emulsification viscosity reduction and emulsion stability, which gives an emulsion viscosity rate of over 98 %. Moreover, the emulsion can be stable for at least 30 days without water emerging.  相似文献   

13.
Laboratory investigations have been undertaken to assess the suitability of heavy oil‐in water emulsions for pipeline transportation. The emulsions contained 65% oil in water and were prepared using polyethoxy nonylphenol surfactants. Two methods were employed for simulating the shear process which accompanies pipeline flow: a bench scale stirred vessel and a rotated pipe toroid. The progress of the emulsions towards inversion, at which point the oil becomes the continuous phase, was followed by measuring the surfactant concentration in the aqueous phase using liquid chromatography. At inversion the surfactant concentration falls below the threshold level required to sustain an oil‐in‐water emulsion. The experiments showed that the lifetime of the emulsion depends upon the initial surfactant dosage, the solids content of the oil, the intensity of shear and the nature of the shear process. Laminar flow was found to be less desirable than turbulent flow.  相似文献   

14.
Pressure loss data in a sudden expansion and a sudden contraction were obtained for two-phase oil/water mixtures, covering a wide range of oil concentration: 0 to 97.3 vol.% oil. The emulsions were of oil-in-water type up to an oil concentration of 64 vol.%. Above this concentration, the emulsions were water-in-oil type. An on-line conductance cell was used to monitor the inversion point and the type of emulsion. The pressure loss was determined from the measured pressure profiles upstream and downstream of the fitting. From the pressure-loss/velocity data, the loss coefficients were obtained. The loss coefficients for the emulsions are found to be independent of the concentration and type of emulsions. Furthermore, there is no observable difference between the loss coefficients for emulsions and single-phase water.  相似文献   

15.
Nanoemulsions of silicone oil and pine oil using a binary surfactant system were prepared. Silicone oil and pine oil were used to achieve softness and mosquito repellency and antibacterial activity respectively when the nanoemulsion was applied on the fabric. A silicone surfactant (AG-pt) and a hydrocarbon surfactant (TDA-6) were used in different proportions to obtain stable nanoemulsions at the lowest possible droplet size. The various emulsification process variables such as ratio of hydrocarbon to silicone surfactant, surfactant concentration, ratio of silicone oil to pine oil, oil weight fraction and sonication time have been studied. The optimal variables include the ratio of hydrocarbon to silicone surfactant of 80:20, surfactant concentration of 8%, ratio of silicone oil to pine oil of 80:20, oil weight fraction of 20% and 15 min of sonication time at 40% of the applied power. Nanoemulsions were found to be very stable with emulsion droplet size around 41 nm. In order to compare different emulsification techniques, emulsions were also prepared using the conventional method. Emulsions analyzed using SEM showed spherical droplets ranging from 40 to 120 nm. Atomic force microscopy was used to evaluate the bounciness, fluffiness and softness of fabric. From this study, it was found that stable nanoemulsion with a lowest possible droplet size of silicone and pine oil could be prepared by ultrasonic emulsification technique in order to deliver multiple properties when applied to fabric.  相似文献   

16.
Many advanced methods are developed for the synthesis of emulsions in the literature, but the effect of imperative parameters of emulsion like oil concentration, pH, temperature, and time on the emulsion stability index (ESI) by design of experiments have not been studied previously. The ESI is an important parameter of emulsion to run the industrial process extensively and reflects the emulsion efficiency to sustain against instability like creaming, coalescence, and flocculation. In the present study, the research plan consists of three phases. In the first phase, the synthesis of an eco-friendly and cost-effective mustard oil-based nanoemulsion with a suitable selection of the surfactant on the bases of the polydispersity index (PDI) is developed. In the next phase emulsions, characteristic properties are scanned by employing various techniques and antirust property compared with reference emulsion. Finally, the impact of emulsion's parameters on ESI is studied by factorial design. The findings that depict the impact of parameters of oil concentration and time on ESI are found influential, whereas the effect of pH and temperature is insignificant. Therefore, good characteristic results, stability, and the inhibition against rust of newly developed emulsion can be adapted to run the cold rolling process smoothly. Practical Application: In the present era, metal processing industries are forced to explore the environmentally friendly oil-in-water emulsions (that used as an interface, lubricant, cooling, and antifrictional agents in cold rolling industries) to overcome increasing environmental pollution. Mustard oil-based emulsion modified by nanoparticles (Nps) offers a good source of eco-friendly, cost-effective, and economic booster for metal processing industries. The antimicrobial properties of mustard oil are well defined in previous research articles. Such oil is a magnificent source for the synthesis of the emulsion and modification of mustard oil-based emulsion with titanium dioxide. Nps provide significant protection against rust. Such applications can encourage the use of mustard oil-based nanoemulsion for metal processing industries.  相似文献   

17.
叔戊醇体系酶促大豆油制备生物柴油   总被引:2,自引:0,他引:2  
叔戊醇作为反应介质,固定化脂肪酶Novozym 435催化大豆油与甲醇的转酯反应制备生物柴油。叔戊醇消除了反应底物甲醇及反应副产物甘油对酶活的负面影响。定量分析表明,叔戊醇与油脂的体积比为1,甲醇与油脂的摩尔比为3,2%脂肪酶,反应体系含水量2%,40 ℃、180 r/min条件下反应15 h,生物柴油得率可达97%。在最适条件下反应进行160批次,酶仍保持了较高的活性和良好的稳定性。  相似文献   

18.
Waste cooking oils (WCO) can be used as feedstock for biodiesel (fatty acid ethyl or methyl esters—FAEE or FAME) production. Their usual high acidity, high moisture, and low stability can impair the reaction yield and generate a low-quality biodiesel. Here, we performed liquid–liquid washings using WCO and ethanol-based solvents with the goal of generating oil-rich miscella as FAEE feedstocks with a higher quality than WCO. Three different solvents were evaluated: 99% ethanol, 95% ethanol, and the soybean oil extraction ethanolic phase (SEP), a by-product with immense unexplored antioxidant potential obtained by extracting soybean oil using ethanol. Washings were performed in a 1000 mL flat-bottom flask at 78.1 °C, using a 1:2 (w/v) oil/solvent ratio, under magnetic stirring (1200 rpm) for 10 min. Ethyl esters were prepared via homogeneous alkali transesterification using WCO and oil-rich miscella as feedstocks. Treatments reduced the acid value by 40–61% and the peroxide value by 15–50%. Improvements in feedstock quality generated 24–54% higher biodiesel yields. The oil-rich phase produced with SEP was 15% more resistant to oxidation than WCO. This was attributed to the transference of isoflavones from the SEP. However, biodiesel from treated samples presented equal or lower oxidative stability than FAEE from WCO. High-performance liquid chromatography (HPLC) analysis showed that no isoflavones remained in biodiesel after purification. Pretreatment of WCO with ethanol-based extracts such as the SEP has great potential to improve WCO quality for biodiesel production as it can be a source of plant-based antioxidants.  相似文献   

19.
BACKGROUND: Emulsions are traditionally formed from two immiscible liquids by mechanical stirring, homogenization, or ultrasonication. For the use of emulsions, stability during storage and transport has been an issue which needs to be addressed. Here, a novel method is proposed to form emulsions instantly by hand shaking from porous polymeric materials. RESULTS: The porous materials were prepared by a freeze‐drying method and then soaked in an oil phase. The oil was absorbed into the micron‐sized pores. The oil‐soaked composites were then placed in water. The dissolution of polymer led to the formation of emulsions by gentle hand shaking within 2 min. Mineral oil, soy oil with drug molecules, and perfluorodecalin were tested as the model oil phases. In each case, stable emulsions with high ratios of oil to water were formed instantly. CONCLUSIONS: A novel route is reported to produce emulsions instantly by hand shaking from porous polymeric materials. Using this method, emulsions could be formed instantly on the site just before application, thus avoiding the cost and stability concerns during transport and storage of emulsions. The method also has the advantages of easy operation and scale‐up possibility. Copyright © 2010 Society of Chemical Industry  相似文献   

20.
A positively charged protein (fish gelatin) or a negatively charged protein species (heat-treated milk protein–carbohydrate mixture) was added to a primary krill oil (KO) emulsion stabilized by the phospholipids inherent in KO, with the aim of improving the oxidative stability of KO-in-water emulsions at pH 8.0 (10 % KO). The positively charged fish gelatin deposited on the primary interface of the oil droplets in the primary KO-in-water emulsion improved the oxidative stability of the KO-in-water emulsion as evidenced by the higher eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) remaining and lower propanal produced after accelerated oxidation (40 °C, 25 days). The addition of the negatively charged heat-treated milk protein–carbohydrate mixture containing Maillard reaction products (MRP) to the bulk phase of the emulsion also enhanced the oxidative stability of the KO-in-water emulsion. The addition of MRP to the aqueous phase of phospholipids stabilized emulsion droplets offered more protection to EPA and DHA of the KO emulsions compared to the formation of an additional layer at the interface of the KO emulsion droplet. This suggests that interventions based on addition of antioxidant species to the formulation were more effective for arresting oxidation than increasing the thickness of the droplet interface. The addition of proteins into KO containing emulsion formulations is a promising strategy for protecting omega-3 marine phospholipids against oxidation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号