Biodiesel Feedstock from Emulsions Produced by Aqueous Processing of Yellow Mustard

The multi-stage treatment of stable oil-in-water emulsions produced during non-enzymatic aqueous processing of dehulled yellow mustard flour with cyclic ethers [tetrahydrofuran (THF) and 1,4-dioxane] was investigated to produce a single-phase oil-solvent-water miscella suitable for biodiesel production. While the single-stage treatment of yellow mustard emulsion recovered 97 % and 95 % of the oil by using 4:1 THF:oil and 9:1 dioxane:oil weight ratios, respectively, miscella phases containing more than 7 % water formed, which made them unsuitable as biodiesel feedstock. Multi-stage treatments of the emulsion using lower THF:oil and dioxane:oil weight ratios were further developed to produce oil-solvent-water miscella phases with low water content. While three-stage extraction of emulsions using 0.5:1, 1:1, 1.5:1, and 2:1 dioxane:oil weight ratios did not destabilize the emulsion, three-stage extraction using 0.5:1 and 0.75:1 THF:oil weight ratios effectively recovered over 97 % of the oil, resulting in the production of oil-rich miscella phases containing only 1 % and 1.5 % water, respectively. These miscella phases were analyzed for free fatty acid and phosphorus contents and proved to be excellent feedstocks for the preparation of high-purity methyl esters through single-phase base-catalyzed transmethylation.     

The Isolation of Yellow Mustard Oil Using Water and Cyclic Ethers

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.     

Application of a Ternary Phase Diagram to the Phase Separation of Oil-in-Water Emulsions Using Isopropyl Alcohol

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.     

Recovery and Recycling of Isopropyl Alcohol Used in Biodiesel Production From Yellow Mustard Oil

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.     

Production of Isopropyl and Methyl Esters from Yellow Mustard Oil/IPA Miscellas

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.     

Isopropyl Alcohol Extraction of De‐hulled Yellow Mustard Flour

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.     

Comparison of Lipid Extraction from Microalgae and Soybeans with Aqueous Isopropanol

The extraction efficiency of microalgae lipids with aqueous isopropanol (IPA) was investigated and compared with the extraction of oil from full-fat soy flour. The effects of the type of microalgae (Scenedesmus sp. and Schizochytrium limacinum), cell rupture, and IPA concentration on the yield of oil and non-lipid biomass were determined. The oil yield from intact cells of Scenedesmus was 86–93 % with 70, 88, or 95 % (by wt) IPA. Ultrasonic cell rupture prior to oil extraction decreased the oil yield of Scenedesmus to 74 % when extracting with 70 % IPA. The oil yield from intact cells of S. limacinum was <23 % regardless of the IPA concentration, but ruptured cells gave a 94–96 % oil yield with 88 or 95 % IPA. The different response of the two microalgae to extraction with IPA is possibly caused by differences in the cell wall structure and type and amount of polar lipids. The oil yield from soy flour with 88 and 95 % IPA was 93–95 %, which was significantly greater than yields with 50 and 70 % IPA. Cell rupture had no effect on soy flour extraction. In general, the oil yield from the ruptured cells of both microalgae and soy flour increased with increasing IPA concentration.     

Development and Scale-up of Aqueous Surfactant-Assisted Extraction of Canola Oil for Use as Biodiesel Feedstock

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.     

The combined application of extrusion and enzymatic technology for extraction of soybean oil

This paper describes a new technological process for soybean oil extraction. The process deals with the combined effect of thermoplastic extrusion of beans and the subsequent action of hydrolytic and proteolytic enzymes in aqueous medium to recover the oil, thus, avoiding solvent application. The thermoplastic extrusion is fundamental for the process, because it facilitates the action of enzymes in oil containing cells, reduces the non-hydratable phosphatides and promotes protein denaturation by reducing the emulsion stability and thus enhancing the oil extraction. The main parameters affecting the oil yield are: the temperature and diameter of the die in the extrusion process, the dilution, the concentration of enzymes and the incubation time of the enzymatic treatment. The highest yield was obtained under the following conditions: extrusion of beans at 90°C and exit die of 6 mm, enzymatic incubation time of 6 h, extruded soy/water dilution ratio 1:10 and concentration of enzyme 6%. With these conditions 88% of the oil were obtained after centrifugation. Moreover, the aqueous enzymatic extraction is easier than solvent extraction, and leads to high value products: a solvent-free meal more suitable for human consumption, a protein hydrolysate that can be used as ingredient for liquid foods and an oil of better quality. The non-hydrolyzed meal contains ca 25% of original soybean protein and the residual oil. The protein hydrolysate in the liquid phase contains ca 75% of the total protein in the original grain with a molecular weight below 20 kDa.     

Enzymatic Demulsification of the Oil-Rich Emulsion Obtained by Aqueous Extraction of Peanut Seeds

This study details the enzymatic destabilization of the emulsion formed during aqueous extraction of peanut seeds and the quality of the resulting oil. The emulsion was exposed to enzymatic treatment and pH adjustment. The experimental results suggest that the alkaline endopeptidase Mifong^®2709 was the most effective demulsifier, while Phospholipase A2 and pH adjustment had little effect on emulsion stability. The demulsifying conditions of Mifong^®2709 were optimized by response surface methodology (RSM). The optimal conditions which produced a free oil yield of ~94 % were: 1:1 water-to-emulsion ratio, enzyme concentration of 1,600 IU/g of emulsion and 70 min hydrolysis time at 50 °C. We found that these conditions resulted in a positive relationship (R ² = 0.9671) between free oil yield and the degree of protein hydrolysis. Increased protease treatment produced a smaller number of oil droplets, but the size of these droplets increased significantly. When compared to demulsified oil products obtained by using thermal treatment, the oil obtained by Mifong^®2709 exhibited lower acid and peroxide values, contained more tocopherols and had a longer induction time as determined in the Rancimat test. The high yield and quality of peanut oil obtained by enzymatic treatment makes enzyme demulsification a promising approach to recovering free oil in aqueous extractions of peanuts.     

Oil extraction from microalga Nannochloropsis sp. with isopropyl alcohol

An efficient process for fractioning microalgae oil and non-lipid biomass was developed. Isopropyl alcohol (IPA) was used to extract oil from Nannochloropsis sp. at 80?°C, leaving the majority of non-lipid biomass in the solid fraction. The effectiveness of extraction with or without a dewatering pretreatment (DW) was compared. Effects of dewatering time and solvent ratio, IPA concentration, IPA refluxing time, and sonication pretreatment on the oil and biomass yields were studied. The dewatering conditions with a high water-to-alcohol ratio (W/A?=?2:1) and mild mixing (1?min gentle shaking) had 14?% less oil loss in the DW fraction than that with a low water-to-alcohol ratio (W/A?=?1:1) and vigorous mixing (30?min and 300?rpm mixing). Sonication resulted in 14–26?% more oil loss in the DW fraction when compared to intact cell treatment. Without dewatering, 85?% of the total oil from intact cells was extracted by a single extraction using 70?% (wt) IPA aqueous solution. The 88 and 95?% IPA treatments extracted similar percentages of oil to that of the 70?% IPA, but used two- and fivefold more solvent. The amount of oil extracted from broken cells increased with increasing IPA concentrations. An effective extraction can be completed in 30?min. On a 100-g (wet matter) scale, the 70?% IPA achieved 92?% oil yield and 93?% non-lipid biomass yield.     

Optimization of an Aqueous Extraction Process for Pomegranate Seed Oil

Response surface methodology employing a five-level, four-variable central composite rotatable design was applied to study the effects of extraction time, extraction temperature, pH and water/solid ratio on the extraction yield of pomegranate seed oil using an aqueous extraction approach. In addition, quality indices, fatty acid composition and antioxidant activity of the obtained oil were studied and compared with those of typical hexane-, cold press- and hot press-extracted oil. Aqueous extraction resulted in the maximum oil recovery of 19.3% (w/w), obtained under the following critical values: water/solid ratio (2.2:1.0, mL/g), pH 5.0, extraction temperature = 63 °C and extraction time = 375 min. This yield is lower than that obtained via hexane extraction (26.8%, w/w) and higher than the yields from cold press (7.0%, w/w) and hot press (8.6%, w/w) extraction. A comparison of the characteristics of the oils based on extraction method revealed that the unsaturated fatty acid content was highest for the oil obtained by aqueous extraction. In addition, higher levels of iodine and peroxide and lower levels of acid, p-anisidine and unsaponifiable matter were observed. The oil obtained with aqueous extraction also exhibited higher antioxidant activity than oils obtained by hexane or hot press extraction.     

Extraction of alcohol using emulsion liquid membrane consisting of paraffin oil as an organic phase and lecithin as a surfactant

BACKGROUND: This paper reports on the use of a liquid emulsion membrane involving paraffin light oil as membrane phase and lecithin as surfactant for the extraction of alcohol from anthocyanin extract and simulated pineapple wine. RESULTS: The extraction of alcohol was found to depend on the many factors such as surfactant concentration, contact time, stirring speed, stirring time, and ratio of membrane emulsion to feed volume. Results showed that optimum conditions for maximum alcohol extraction (25%) were lecithin concentration 3%, contact time 20 min, stirring speed 250 rpm and ratio of membrane emulsion to feed volume 1:2. Multistage extraction using this liquid emulsion membrane was found to completely remove alcohol from anthocyanin extract and from simulated pineapple wine in seven stages and five stages, respectively. CONCLUSION: This liquid emulsion membrane was found to be a useful method for the extraction of alcohol from aqueous feed. Copyright © 2009 Society of Chemical Industry     

乳状液膜法提取红土矿浸出液中镍

采用Span-80-TBP-NH3×H2O体系乳状液膜法提取红土矿浸出液中的Ni(II),研究了膜相组成、内水相试剂浓度、膜相与内水相体积比(油内比)、乳水体积比对镍离子提取效果的影响. 采用微分法测定并比较了反应的浓度级数nC和时间级数nt. 结果表明,膜相组成为Span-80:TBP:石蜡:煤油(体积比)=5:4:2:89、内水相氨水浓度为2 mol/L、油内比为1:1、乳水体积比为1:3、外水相硫酸浓度为0.3 mol/L的条件下,经过二级提取后,红土矿浸出液中Ni(II)去除率可达80%;由浓度级数(nC=1)小于时间级数(nt=2.8)可知,该过程为化学反应控制过程.     

Effect of ultrasound- and pulsed electric field-assisted enzymatic treatment on the recovery and quality of sunflower oil

The aim of this study was to evaluate the effect of cavitation and electroporation on enzymolysis extraction of sunflower oil. The optimum extraction conditions during 2 h under enzyme-assisted extraction (EAE) with a maximum oil yield of ≈23.70 ± 0.11% were as follows: cellulase/pectinase ratio 2:1, enzyme concentration 2%, pH 4.5, liquid/solid ratio 6:1 ml/g, and extraction temperature 40°C. Under the optimized enzymatic conditions, the application of ultrasound- (250 W) and pulsed electric field- (1.2 kV/cm; 52.4 kJ/kg) assisted enzymatic extraction for 30 min significantly increased the oil extraction yield by 91.1% and 18.6%, respectively, as compared with EAE.     

Synthesis of a Series of Anionic Surfactants Derived from NP and their Properties as Emulsifiers for Reducing Viscosity of Highly Viscous Oil via Formation of O/W Emulsions

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.     

Optimization of Enzymatic Hydrolysis of Sacha Inchi Oil using Conventional and Supercritical Carbon Dioxide Processes

Sacha inchi (Plukenetia volubilis) oil has high polyunsaturated fatty acids content. The hydrolysis of this oil is an efficient way to obtain desirable free fatty acids (FFA). The optimization of parameters was carried out according to the maximum production of FFA using two enzymatic hydrolysis processes. The effect of enzyme concentration (5–40 % based on weight of oil), temperature (40–60 °C), and oil:water molar ratio (1:5–1:70) were studied for the conventional enzymatic hydrolysis process, while pressure (10–30 MPa) and oil:water molar ratio (1:5–1:30) were studied for the enzymatic hydrolysis in supercritical carbon dioxide (SC-CO₂) media. The hydrolysis in SC-CO₂ media resulted in higher production of FFA (77.98 % w/w) at 30 MPa and an oil:water molar ratio equal to 1:5 compared to the conventional process (68.40 ± 0.98 % w/w) at 60 °C, oil:water molar ratio equal to 1:70, and 26.17 % w/w, enzyme/oil. The only significant parameter on the production of FFA for conventional enzymatic hydrolysis was enzyme concentration, while for the hydrolysis in SC-CO₂ media both pressure and the molar ratio of oil:water were significant. Lipid class analyses showed that with both methods, FFA, monoglycerides, and diglycerides content in the final product increased compared to pure oil, while triglycerides content decreased. Fatty acid composition analysis showed that the content of fatty acids in the FFA form were similar to their triglyceride form.     

Enrichment of DHA from Tuna Oil in a Packed Bed Reactor via Lipase-Catalyzed Esterification

A packed-bed reactor (length 6.5 cm; id 4.65 mm) has been used to enrich docosahexaenoic acid (DHA) via the lipase-catalyzed esterification of the fatty acid from tuna oil with ethanol. Lipozyme RM IM (from Rhizomucor miehei) was used for the esterification reaction because of its ability to discriminate between different fatty acids, and several reaction parameters, including the temperature, molar ratio of substrates, and water content were explored as a function of residence time. In this way, the optimum conditions for the enrichment process were determined to be a temperature of 20 °C, a molar ratio of 1:5 (i.e., fatty acid to ethanol), and a water content of 1.0 % (based on the total substrate weight). Under these conditions, a residence time of 90 min gave a DHA concentration of 70 wt% and a DHA recovery yield of 87 wt% in the residual fatty acid fraction.     

煤油-司班80-氢氧化钠液膜分离氨基苯酚的研究

对煤油-司班80-氢氧化钠乳化液膜处理氨基苯酚(邻、间、对氨基苯酚)水溶液的过程作了系统研究,当液膜质量百分比组成为煤油95%,Span 80 5%,内水相的质量百分比浓度为2.5%,油内比1∶1,乳水比1∶5(均为体积比),乳水混合搅拌速率为200 r/min,萃取时间为20 min时,对氨基苯酚脱除率可达75%以上。     

Optimization of Ethanol-Ultrasound-Assisted Destabilization of a Cream Recovered from Enzymatic Extraction of Soybean Oil

A novel method using ethanol and ultrasound to extract oil from cream obtained from enzyme-assisted aqueous extraction of soybean oil was developed. To evaluate the relationships between operating variables and free oil yield and to maximize the free oil yield, response surface methodology was introduced in this work. The developed regression model was fitted with R ² = 0.9591. Optimized variables were: ethanol concentration of 73 %, ethanol addition volume of 0.55 L/kg, ultrasound power of 427 W, ultrasound time of 47 s, and ultrasound temperature of 53 °C. The free oil yield from the cream under the above conditions was 92.6 ± 3.4 %. Scanning electron microscopy (SEM) was used to evaluate the effect of ultrasonic treatment on ethanol-treated cream, and the SEM images clearly showed that the ultrasound treatment affected dispersing and fracturing of the microstructure of ethanol-treated cream.