共查询到20条相似文献,搜索用时 31 毫秒
1.
Jun-Ho Yun Hye-Youn Lee A.K.M. Asaduzzaman Byung-Soo Chun 《Journal of Industrial and Engineering Chemistry》2013,19(2):686-691
Lecithin was isolated from squid viscera residues after supercritical carbon dioxide (SC-CO2) extraction at 25 MPa and 45 °C. The particle formation of squid lecithin with biodegradable polymer, polyethylene glycol (PEG) was performed by PGSS using SC-CO2 in a thermostatted stirred vessel. By applying different temperatures (40 and 50 °C) and pressures (20–30 MPa), conditions were optimized. Two nozzles of different diameters (250 and 300 μm) were used for PGSS and the reaction time was 1 h. The average diameter of the particles obtained by PGSS at different conditions was about 0.74–1.62 μm. The lowest average size of lecithin particle with PEG was found by the highest SC-CO2 density conditions with the stirring speed of 400 rpm and nozzle size of 250 μm. The inclusion of lecithin in PEG was quantified by HPLC. Acid value and peroxide value was measured after micronization of lecithin. 相似文献
2.
Conversion of oils to monoglycerides by glycerolysis in supercritical carbon dioxide media 总被引:1,自引:0,他引:1
Feral Temelli Jerry W. King Gary R. List 《Journal of the American Oil Chemists' Society》1996,73(6):699-706
Glycerolysis of soybean oil was conducted in a supercritical carbon dioxide (SC-CO2) atmosphere to produce monoglycerides (MG) in a stirred autoclave at 150–250°C, over a pressure range of 20.7–62.1 MPa, at
glycerol/oil molar ratios between 15–25, and water concentrations of 0–8% (wt% of glycerol). MG, di-, triglyceride, and free
fatty acid (FFA) composition of the reaction mixture as a function of time was analyzed by supercritical fluid chromatography.
Glycerolysis did not occur at 150°C but proceeded to a limited extent at 200°C within 4 h reaction time; however, it did proceed
rapidly at 250°C. At 250°C, MG formation decreased significantly (P<0.05) with pressure and increased with glycerol/oil ratio and water concentration. A maximum MG content of 49.2% was achieved
at 250°C, 20.7 MPa, a glycerol/oil ratio of 25 and 4% water after 4 h. These conditions also resulted in the formation of
14% FFA. Conversions of other oils (peanut, corn, canola, and cottonseed) were also attempted. Soybean and cottonseed oil
yielded the highest and lowest conversion to MG, respectively. Conducting this industrially important reaction in SC-CO2 atmosphere offered numerous advantages, compared to conventional alkalicatalyzed glycerolysis, including elimination of the
alkali catalyst, production of a lighter color and less odor, and ease of separation of the CO2 from the reaction products. 相似文献
3.
Response Surface Analysis and Modeling of Flaxseed Oil Yield in Supercritical Carbon Dioxide 总被引:1,自引:0,他引:1
Sami Gökhan Özkal 《Journal of the American Oil Chemists' Society》2009,86(11):1129-1135
Supercritical fluid extraction of flaxseed oil with carbon dioxide was performed. Effects of particle size, pressure, temperature
and the flow rate of supercritical carbon dioxide (SC-CO2) were investigated. Response surface methodology was used to determine the effects of pressure (30–50 MPa), temperature (50–70 °C)
and SC-CO2 flow rate (2–4 g/min) on flaxseed oil yield in SC-CO2. The oil yield was represented by a second order response surface equation (R
2 = 0.993) using the Box-Behnken design of experiments. The oil yield increased significantly with increasing pressure (p < 0.01), temperature (p < 0.05) and SC-CO2 flow rate (p < 0.01). The maximum oil yield from the response surface equation was predicted as 0.267 g/g flaxseed for 15 min extraction
of 5 g flaxseed particles (particle diameter <0.850 mm) at 50 MPa pressure and 70 °C temperature, with 4 g/min solvent flow
rate. Total extraction time at these conditions was predicted as 22 min. 相似文献
4.
Edgar Uquiche Ximena Fica Katherine Salazar José M. del Valle 《Journal of the American Oil Chemists' Society》2012,89(6):1135-1144
This work explored the possibility of using supercritical carbon dioxide (SC-CO2) to achieve fractionation of pre-pressed rapeseed (Brassica napus) cake oil at 30–50 MPa, at 40 or 80 °C, and increase the concentration of minor lipids (sterols, tocopherols, carotenoids) in the oil. Minor lipids are partially responsible for desirable antioxidant effects that protect against degradation and impart functional value to the oil. The weight and concentration of minor lipids in oil fractions collected during the first 60 min were analyzed. Cumulative oil yield increased with pressure, and with temperature at ≥40 MPa, but was lower at 80 °C than at 40 °C when working at pressure ≤35 MPa. Differences in solubility between the oil and minor lipids explained fractionation effects that were small for tocopherols. Unlike tocopherols, which are more soluble in SC-CO2 than the oil, sterols and carotenoids are less soluble than the oil, and their concentration increased in the later stages of extraction, particularly at ≥40 MPa, when there was not enough oil to saturate the CO2 phase. Because of the fractionating effects on rapeseed oil composition, there was an increase in the antioxidant activity of the oil in the second half as compared to the first half of the extraction. Consequently, this study suggests that SC-CO2 extraction could be used to isolate vegetable oil fractions with increased functional value. 相似文献
5.
Vanesa Y. Ixtaina Facundo Mattea Damián A. Cardarelli Miguel A. Mattea Susana M. Nolasco Mabel C. Tomás 《Journal of the American Oil Chemists' Society》2011,88(2):289-298
Extraction of chia seed oil was performed with supercritical carbon dioxide (SC-CO2). To investigate the effects of pressure and temperature on the oil solubility and yield, two isobaric (250 and 450 bar)
and two isothermal (40 and 60 °C) extraction conditions were selected. The global extraction yield of chia oil increased with
pressure enhancement, but temperature had a little influence on it. The maximum oil recovery using SC-CO2 at a mass flow rate of 8 kg/h was 97%, which was obtained at 60 °C, 450 bar for a 138-min extraction. The results showed
that solubility changed from 4.8 g oil/kg CO2 at 60 °C–250 bar to 28.8 g oil/kg CO2 at 60 °C–450 bar. The final extract obtained by SC-CO2 under different conditions and Soxhlet extraction contained mainly α-linolenic (64.9–65.6%) and linoleic (19.8–20.3%) acids.
SC-CO2 extraction is an interesting alternative methodology because it is possible to achieve a chia oil yield close to that obtained
by conventional extraction with a similar fatty acid composition using an environmentally friendly process. 相似文献
6.
Kinetic modeling of the glycerolysis reaction for soybean oils in supercritical carbon dioxide media 总被引:1,自引:0,他引:1
Production of MAG by glycerolysis is important for food, pharmaceutical, and cosmetic industries. Conducting glycerolysis
in supercritical carbon dioxide (SC-CO2) media has advantages over conventional alkali-catalyzed glycerolysis. However, kinetic data are lacking for such conversions
in the presence of SC-CO2. The objectives of this study were to estimate the rate constants and elucidate the mechanism for the glycerolysis of soybean
oil in SC-CO2 using previously reported data. The data were taken from experiments using soybean oil, glycerol (glycerol/oil molar ratios
of 15–25) and water (3–8% w/w) in SC-CO2 at 20.7–62.1 MPa and 250°C for a 4 h period. Rate constants for the parallel glycerolysis and hydrolysis reactions were estimated
for each processing parameter (glycerol/oil, water content, pressure) by minimizing the summed squared error between the values
calculated from the experimental data and those obtained from the kinetic model. The results suggested that water and pressure
had an effect on rate constants but the glycerol/oil ratio did not. Findings provide the kinetic modeling data necessary for
the optimization of supercritical processes involving glycerolysis reactions for the production of MAG from vegetable oils. 相似文献
7.
S. D. Arntfield N. R. Bulley W. J. Crerar 《Journal of the American Oil Chemists' Society》1992,69(8):823-825
Differential scanning calorimetry (DSC) was used to monitor changes in protein conformation resulting from supercritical carbon
dioxide (SC-CO2) extraction of lipids from egg yolk. Extraction temperatures of 65°C and lower had no effect on protein conformation as indicated
by similar denaturation temperatures and enthalpies of denaturation (ΔH). An extraction temperature of 75°C resulted in a
reduction in the ΔH value for ovalbumin present in the egg yolk. The use of 3% methanol as an entrainer during extraction
at 36 MPa and 40°C resulted in a 50% reduction in the ΔH value for ovalbumin. The use of high temperatures and/or entrainers
during SC-CO2 extraction can result in significant protein denaturation. 相似文献
8.
The rapid expansion of a supercritical solution (RESS) process is an attractive technology for the production of small, uniform
and solvent-free particles of low vapor pressure solutes. The RESS containing a nonvolatile solute leads to loss of solvent
power by the fast expansion of the supercritical solution through an adequate nozzle, which can cause solute precipitation.
A dynamic flow apparatus was used to perform RESS studies for the preparation of fine anthracene particles in pure carbon
dioxide over a pressure range of 150–250 bar, an extraction temperature range of 50–70 °C, and a pre-expansion temperature
range of 70–300 °C. To obtain fine particles, 100, 200 and 300 μm nozzles were used to disperse the solution inside of the
crystallizer. Both average particle size and particle size distribution (PSD) were dependent on the extraction pressure and
the pre-expansion temperature, whereas extractor temperature did not exert any significant effect. Smaller particles were
produced with increasing extraction pressure and preexpansion temperature. In addition, the smaller the nozzle diameter, the
smaller the particles and the narrower the PSD obtained. 相似文献
9.
Brunetti L. Daghetta A. Fedell E. Kikic I. Zanderighi L. 《Journal of the American Oil Chemists' Society》1989,66(2):209-217
An investigation of the application of supercritical carbon dioxide (SC-CO2) extraction to the deacidification of olive oils has been made to verify that the nutritional properties of the oil remain
unchanged when this technique is applied.
Preliminary runs at 20 and 30 MPa in the temperature range of 35–60°C were performed on fatty acids and triglycerides as pure
compounds or mixtures, to determine their solubility in SC-CO2. The solubility data obtained show that CO2 extracts fatty acids more selectively than triglycerides under specific conditions of temperature and pressure (60°C and
20 MPa). It has been noted that the physical state of the solutes plays an important role in determining the solubility trends
as a function of temperature and pressure.
Extraction of free fatty acids from olive oil was performed on samples with different free fatty acid (FFA) contents at 20
and 30 MPa and at 40 and 60°C. Experimental data suggest that the selectivity factor for fatty acids is higher than 5 and
increases significantly as the fatty acid concentration of the oil decreases. For a FFA content of 2.62%, the selectivity
reaches a value of 16.
In order to evaluate any variations in the composition, several SC-CO2 extractions of husk oil with high FFA content (29.3%) were made. The results show that selectivity is still significant (≈5)
and the composition in the minor component of the deacidified oil has not changed. On the basis of the experimental results
and preliminary process evaluations, the authors conclude that SC-CO2 extraction could be a suitable technique for the deacidification of olive oils, especially for oils with relatively high
FFA (<10%). 相似文献
10.
Xiaohui HuYanni Guo Lei WangDan Hua Yanzhen HongJun Li 《The Journal of Supercritical Fluids》2011,57(1):66-72
A supercritical fluid-based method is proposed to produce coenzyme Q10 (CoQ10) nanoparticles. First, CoQ10/polyethylene glycol 6000 composite particles are prepared by a modified PGSS (particles from gas-saturated solutions) process with controlling the flow rate of the gas-saturated solution. Then, CoQ10 nanoparticles are obtained by dissolving the composite particles into water. The effect of experimental variables of the modified PGSS process, including pressure, temperature, flow rate of the gas-saturated solution, and mass fraction of CoQ10, on the CoQ10 particle size and particle size distribution was investigated. Results show that CoQ10 slurry product with a median diameter of 190 nm and yield of 89.8% can be prepared at an optimum condition (operating pressure of 25 MPa, operating temperature of 80 °C, gas-saturated solution flow rate of 1.02 mL/min, CoQ10 mass fraction of 40% and nozzle diameter of 100 μm) via the supercritical fluid-based method. 相似文献
11.
Supercritical CO2 extraction of flaxseed 总被引:2,自引:0,他引:2
Extraction of flaxseed oil was performed with supercritical carbon dioxide (SC-CO2). To investigate the effects of pressure and temperature on the solubility of oil and oil yield, three isobaric (21, 35,
and 55 MPa) and two isothermal (50 and 70°C) extraction conditions were selected. Although the maximal solubility of flaxseed
oil, 11.3 mg oil/g CO2, was obtained at 70°C/55 MPa, the oil yield obtained after 3 h of extraction at this condition was only 25% (g oil/g seed×100),
which represented 66% of the total available oil of the flaxseed. Lipid composition and FFA and tocol (tocopherol and tocotrienol)
contents of the oils obtained by both SC-CO2 and petroleum ether extraction were determined. The α-linolenic acid content of the SC-CO2-extracted oil was higher than that obtained by solvent extraction. 相似文献
12.
Benjapol Kongsombut Wei Chen Atsushi Tsutsumi Wiwut Tanthapanichakoon Tawatchai Charinpanitkul 《Korean Journal of Chemical Engineering》2008,25(4):838-845
Rapid expansion of supercritical solution (RESS) was used for preparing polymer particles and polymer coating of ultra fine
powders. The polymer of pharmaceutical interest was Poly(lactic-co-glycolic acid) (PLGA with PLA: PGA ratio of 85: 15 and
MW of 50,000–75,000) and the simulated core particles were 1.4-μm SiO2 and 70-nm TiO2 particles. The supercritical solution was prepared by dissolving PLGA in supercritical carbon dioxide with ethanol as a cosolvent.
Supercritical solution of CO2-PLGA was sprayed through capillary nozzles to ambient conditions, resulting in formation of submicron PLGA particles. Similarly,
rapid expansion of supercritical solution of CO2-PLGA suspended with the core particles could provide solvent evaporation and deposition of submicron PLGA particles on the
surface of the core particles, resulting in the formation of coating films on dispersed particles of SiO2 and agglomerates of TiO2. The influences of the core particle size, spray nozzle diameter as well as powder-to-polymer weight ratio were also investigated
and discussed with respect to the coating performance. 相似文献
13.
Jin-Yuan Zhou Zhi-Yong Chen Ming Zhou Xiu-Ping Gao Er-Qing Xie 《Nanoscale research letters》2009,4(8):814-819
Well-crystallized β-SiC nanorods grown on electrospun nanofibers were synthesized by carbothermal reduction of Tb doped SiO2 (SiO2:Tb) nanofibers at 1,250 °C. The as-synthesized SiC nanorods were 100–300 nm in diameter and 2–3 μm in length. Scanning electron
microscopy (SEM) results suggested that the growth of the SiC nanorods should be governed by vapor-liquid-solid (VLS) mechanism
with Tb metal as catalyst. Tb(NO3)3 particles on the surface of the electrospun nanofibers were decomposed at 500 °C and later reduced to the formation of Tb
nanoclusters at 1,200 °C, and finally the formation of a Si–C–Tb ally droplet will stimulate the VLS growth at 1,250 °C. Microstructure
of the nanorod was further investigated by transmission electron microscopy (TEM). It was found that SiC <111> is the preferred
initial growth direction. The liquid droplet was identified to be Si86Tb14, which acted as effective catalyst. Strong green emissions were observed from the SiC nanorod samples. Four characteristic
photoluminescence (PL) peaks of Tb ions were also identified. 相似文献
14.
Abdelkader Ali-Nehari Seon-Bong Kim Yang-Bong Lee Hye-youn Lee Byung-Soo Chun 《Korean Journal of Chemical Engineering》2012,29(3):329-336
Krill oil including astaxanthin was extracted using supercritical CO2 and hexane. The effects of different parameters such as pressure (15 to 25MPa), temperature (35 to 45 °C), and extraction
time, were investigated. The flow rate of CO2 (22 gmin−1) was constant for the entire extraction period of 2.5 h. The maximum oil yield was found at higher extraction temperature
and pressure. The oil obtained by SC-CO2 extraction contained a high percentage of polyunsaturated fatty acids, especially EPA and DHA. The acidity and peroxide value
of krill oil obtained by SC-CO2 extraction were lower than that of the oil obtained by hexane. The SC-CO2 extracted oil showed more stability than the oil obtained by hexane extraction. The amount of astaxanthin in krill oil was
determined by HPLC and compared at different extraction conditions. The maximum yield of astaxanthin was found in krill oil
extracted at 25 MPa and 45 °C. 相似文献
15.
Junho Chu Hanho Lee Hwayong Kim Youn-Woo Lee 《Korean Journal of Chemical Engineering》2009,26(4):1119-1124
Tetracycline hydrochloride (TTC) was micronized by an Aerosol Solvent Extraction System (ASES) using supercritical CO2. The effects of solvent, pressure and temperature of CO2, solution concentration, and solution feed rate on particle size were investigated. Mean particle sizes of processed TTC
were 0.16–0.31 μm, but the morphologies of processed particles were affected by agglomeration between the primary particles.
Mean particle sizes of unprocessed TTC were ca. 200 μm and the shapes were irregular with rough surfaces. Especially, particle sizes increased from 0.18 to 0.31 μm as CO2 temperature increased. In addition, particle sizes increased from 0.18 to 0.23 μm as TTC concentration increased. Powder
X-Ray diffractometry revealed that processed particles were amorphous whereas unprocessed particles showed strong crystallinity. 相似文献
16.
Controllable Synthesis of Magnesium Oxysulfate Nanowires with Different Morphologies 总被引:1,自引:0,他引:1
One-dimensional magnesium oxysulfate 5Mg(OH)2 · MgSO4 · 3H2O (abbreviated as 513MOS) with high aspect ratio has attracted much attention because of its distinctive properties from those
of the conventional bulk materials. 513MOS nanowires with different morphologies were formed by varying the mixing ways of
MgSO4 · 7H2O and NH4OH solutions at room temperature followed by hydrothermal treatment of the slurries at 150 °C for 12 h with or without EDTA.
513MOS nanowires with a length of 20–60 μm and a diameter of 60–300 nm were prepared in the case of double injection (adding
MgSO4 · 7H2O and NH4OH solutions simultaneously into water), compared with the 513MOS with a length of 20–30 μm and a diameter of 0.3–1.7 μm in
the case of the single injection (adding MgSO4 · 7H2O solution into NH4OH solution). The presence of minor amount of EDTA in the single injection method led to the formation of 513MOS nanowires
with a length of 100–200 μm, a diameter of 80–200 nm, and an aspect ratio of up to 1000. The analysis of the experimental
results indicated that the hydrothermal solutions with a lower supersaturation were favorable for the preferential growth
of 513MOS nanowires along b axis. 相似文献
17.
Synthesis and optical properties of cocoon-like poly(methyl methacrylate) (CPM) particles in the size range of D
n
= 3.0–6.5 μm were studied. The synthesis of these anisotropic particles consists of two steps. The spherical poly(methyl
methacrylate) (PMA) particles (D
n
= 2.2–5.5 μm) cross-linked by 0.2–0.8 wt% ethylene glycol dimethacrylate (EGDMA) were prepared by dispersion polymerization,
using a combination of poly(vinyl pyrrolidone) (PVP) and sodium di-(2-ethylhexyl) sulfosuccinate (NaEHS) as a stabilizer in
94:840 water–methanol. Then, a suspension polymerization of 9:1 methyl methacrylate (MMA)/EGDMA in the presence of the PMA
particles as seed at 85 °C in water gave non-spherical, cocoon-like CPM particles, depending on the cross-linking densities
of PMA particles. The cocoon-like CPM particles (D
n,c
= 4.0 μm) showed the characteristic features of regular reflection, which can not be attained for conventional poly(methyl
methacrylate) particles with a spherical shape. The effects of seed PMA particles with different properties on the formation
of cocoon-like CPM particles and their regular reflection properties are described. 相似文献
18.
Felipe Sperotto Junsi Yang Loren Isom Curtis Weller Ozan N. Ciftci 《Journal of the American Oil Chemists' Society》2022,99(5):433-441
The objective of this work was to obtain high purity natural wax from sorghum and by-products of sorghum processing (sorghum dried distillers grains with solubles [DDGS] and sorghum bran) using a green process based on supercritical carbon dioxide (SC-CO2). SC-CO2 extractions were carried out at varying temperatures (50, 70°C) and pressures (30, 40 MPa) at a CO2 flow rate 1 L/min for 120 min. Significantly higher wax yield (4.9%) from DDGS was obtained by SC-CO2 at 40 MPa/70°C compared with whole kernel (0.6%) and bran (3.3%) (p < 0.05). The yield of the extracts obtained by SC-CO2 extraction was higher than that of the conventional hexane extraction for all three sorghum sources. The highest fraction of wax in the SC-CO2 extracts was obtained from whole kernel extracts (89%), whereas it was 53.3% from the DDGS and 26.8% from the bran at the same extraction conditions. SC-CO2 and hexane extracts from sorghum whole kernel shared a similar melting peak temperature of 76.3–77.9 and 79.7°C, respectively, while DDGS and bran extracts by SC-CO2 showed a much lower melting temperature in the range of 50.7–61.9°C, indicating the presence of lower melting point components such as triacylglycerols. However, the melting points of the DDGS and bran extracts after ethanol purification were significantly increased with the observed peak temperature of 80.8 and 82.0°C, respectively. While the wax yield from DDGS and bran was higher than that of whole kernel, the sorghum whole kernel feedstock was found to be a more feasible feedstock to obtain higher purity wax. 相似文献
19.
Supercritical CO2 extraction of rice bran 总被引:3,自引:0,他引:3
Extraction of rice bran lipids with supercritical carbon dioxide (SC-CO2) was performed. To investigate the pressure effect on extraction yield, two isobaric conditions, 7000 and 9000 psi, were
selected. A Soxhlet extraction with hexane (modified AOCS method Aa 4–38; 4 h at 69°C) was also conducted and used as the
comparison basis. Rice bran with a moisture content of 6%, 90% passable through a sieve with 0.297 mm opening, was used for
extraction. A maximum rice bran oil (RBO) yield of 20.5%, which represents 99+% lipid recovery, was obtained with hexane.
RBO yield with SC-CO2 ranged between 19.2 and 20.4%. RBO yield increased with temperature at isobaric conditions. At the 80°C isotherm, an increase
in RBO yield was obtained with an increase in pressure. The pressure effect may be attributed to the increase in SC-CO2 density, which is closely related to the value of the Hildebrand solubility parameter. RBO extracted with SC-CO2 had a far superior color quality when compared with hexane-extracted RBO. The level of sterols in SC-CO2-extracted RBO increased with pressure and temperature. 相似文献
20.
P. Kashulines S. S. H. Rizvil P. Harriott J. A. Zollweg 《Journal of the American Oil Chemists' Society》1991,68(12):912-921
The viscosities of several types of lipids saturated with supercritical carbon dioxide (SC-CO2) were measured with a high-pressure capillary viscometer. Oleic acid and linoleic acid were evaluated from 85 to 350 bar
at 40 and 60°C. The more SC-CO2-soluble methylated derivatives of these fatty acids were evaluated from 90 to 170 bar at 40 and 60°C. The complex mixture
of anhydrous milk fat (AMF) was evaluated from 100–310 bar at 40°C. The viscosities of the methylated fatty acids saturated
with SC-CO2 decreased between 5 and 10 times when the pressure increased from 1 to 80 bar, followed by a further decrease by a factor
of 2 to 3 when the pressure was increased from 80 to 180 bar. The viscosities of the fatty acids and AMF saturated with SC-CO2 had viscosity reduction similar to the methylated fatty acids between 1 and 80 bar, but they decreased much less between
80 and 350 bar. At constant pressure, the viscosity of the fatty acids and AMF decreased with increasing temperature, whereas
the viscosity of the methylated fatty acids increased with increasing temperature. The lipid/SC-CO2 mixtures were Newtonian, and their viscosities were best interpreted by using the mass concentration of dissolved SC-CO2 in the lipids and the pure component viscosities. 相似文献