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1.
Kriti Bhandari S. P. Chaurasia A. K. Dalai Alok Gupta 《Journal of the American Oil Chemists' Society》2013,90(11):1637-1644
Tuna fish oil contains 25–30 % docosahexaenoic acid (DHA) and is one of the richest sources of DHA. The present paper investigates the enrichment of DHA by selective esterification of fatty acids obtained from hydrolysis of tuna fish oil catalyzed by Rhizopus oryzae lipase (ROL). The fatty acid mixture obtained after hydrolysis of tuna fish oil, referred to as tuna-FFA contained 26 % DHA. For purification/concentration of DHA in free fatty acids, selective esterification of the fatty acid mixtures with butanol was carried out using ROL in a water-organic solvent system. The best reaction parameters found in this study were pH 7, temperature 35 °C, agitation speed 800 rpm and a fatty acid to solvent (iso-octane) ratio of 1:1.32 (w/v). Also, the effects of other parameters such as type of alcohol, type of enzyme, alcohol to fatty acid ratio, enzyme to fatty acid ratio were studied to determine the most suitable reaction conditions. Exactly 76.2 % of tuna-FFA was esterified in 24 h, under the most suitable reaction conditions and the DHA content in the fatty acid fraction rose from 26 to 86.9 % with 80 % recovery of DHA, after selective esterification. The DHA content of fatty acids in butyl esters was found to be 13.6 %. 相似文献
2.
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
3.
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
4.
Luis Vázquez Leslie Kleiner Casimir C. Akoh 《Journal of the American Oil Chemists' Society》2012,89(9):1655-1662
The concentration of stearidonic acid (SDA, 18:4 n-3) in free fatty acids (FFA) formed by selective esterification with dodecanol (lauryl alcohol) was studied. For this purpose, modified soybean oil (initial SDA content, ~23 %) was converted into its corresponding FFA by chemical hydrolysis. In a second step, the resulting FFA were esterified with dodecanol. Process variables such as the type of biocatalyst (lipase), substrate molar ratio and amount of lipase were evaluated. The best SDA concentration (58 %) and recovery (94 %) were attained by performing the esterification reaction for 4 h, with 1:1 molar ratio (dodecanol:FFA), and 5 % (w/w) Candida rugosa lipase as biocatalyst. It was observed that SDA was concentrated in the unesterified fraction. 相似文献
5.
Xiao-Qin Yang Hui Pan Tao Zeng Todd F. Shupe Chung-Yun Hse 《Journal of the American Oil Chemists' Society》2013,90(3):459-466
Seeds were collected from locally and naturally grown Chinese tallow trees (CTT) and characterized for general physical and chemical properties and fatty acid composition of the lipids. The effects of four different solvents (petroleum ether, hexane, diethyl ether, and 95 % ethanol) and two extraction methods (supercritical carbon dioxide (SC-CO2) and conventional Soxhlet) on the properties of the CTT seed oil, including Chinese vegetable tallow (CVT) and stillingia oil (SO), were also investigated. In general, the yields of CVT and SO did not vary based on solvent for Soxhlet extraction and solvent-free SC-CO2 extraction, except that the yield of CVT from SC-CO2 extraction was substantially lower. Nevertheless, the CTT seed oil, extracted by SC-CO2 displayed better quality than those extracted by Soxhlet extraction in terms of color, residual precipitation, and acid value of the oils. The pretreatment of CTT seed by 3 % aqueous sodium bicarbonate solution likely promoted the hydrolysis of triglyceride and caused the high acid value in the CVT samples. The iodine value at around 180 indicated that the SO is a highly unsaturated drying oil. Palmitic (76 %) and oleic (23 %) are two dominant fatty acids in CVT while linolenic (43 %), linoleic (31 %), and oleic (13 %) are the dominant fatty acids in SO. 相似文献
6.
Simultaneous Enzymatic Transesterification and Esterification of an Acid Oil Using Fermented Solid as Biocatalyst
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Erika C. G. Aguieiras Elisa D. Cavalcanti-Oliveira Aline M. de Castro Marta A. P. Langone Denise M. G. Freire 《Journal of the American Oil Chemists' Society》2017,94(4):551-558
This work studied the enzymatic synthesis of fatty acid ethyl esters (FAEE) for potential use as biodiesel via simultaneous esterification and transesterification of acid oil from macaúba in a solvent-free system. A fermented and dry babassu cake with lipase activity from Rhizomucor miehei was used as biocatalyst. FAEE content above 85% was achieved after 96 h of reaction with enzyme loading of 13 U per g of oil, 120 mmol of hydrous ethanol (95% ethanol and 5% water)/20 mmol of oil (molar ratio ethanol:oil of 6:1), at 40 °C. After two consecutive enzymatic reactions, 90.8 wt% FAEE content was obtained. These results demonstrate a promising transesterification/esterification method for FAEE production from an acid and low-cost oil and the process has potential to decrease the costs of enzymatic biodiesel production. 相似文献
7.
《分离科学与技术》2012,47(4):605-610
Extraction of lutein fatty acid esters from marigold flower using supercritical carbon dioxide (SC-CO2) with cosolvent was investigated. Without the cosolvent, the total xanthophylls yield increased with increasing temperature and pressure of SC-CO2, and the optimal condition was found to be at 60°C and 40 MPa. At this condition, the highest total xanthophylls percent recovery was 74.4 ± 0.9%. Palm oil was found to be a more efficient cosolvent than soybean oil, olive oil, and ethanol, resulting in a 16% increase in the total xanthophylls recovery to 87.2 ± 4.4% when 10% (w/w) of palm oil was used. Furthermore, saponification of the oleoresin for 3 h at 75°C with 40% w/v KOH solution at the oleoresin to solution ratio of 1 g to 2 ml was found to suitably convert lutein fatty acid esters into free lutein. 相似文献
8.
Preparation of Diacylglycerol-Enriched Oil from Free Fatty Acids Using Lecitase Ultra-Catalyzed Esterification 总被引:1,自引:0,他引:1
Lili Wang Yong Wang Changying Hu Qian Cao Xiaohui Yang Mouming Zhao 《Journal of the American Oil Chemists' Society》2011,88(10):1557-1565
Production of diacylglycerol-enriched oil by esterification of free fatty acids (FFA) with glycerol (GLY) using phospholipase
A1 (Lecitase Ultra) was investigated in this work. The variables including reaction time (2–10 h), water content (2–14 wt%,
FFA and GLY mass), enzyme load (10–120 U/g, FFA and GLY mass), reaction temperature (30–70 °C) and mole ratio of GLY to FFA
(0.5–2.5) were studied. The optimum conditions obtained were as follows: reaction temperature 40 °C, water content 8 wt%,
reaction time 6 h, molar ratio of GLY to FFA 2.0, and an enzyme load of 80 U/g. Under these conditions, the esterification
efficiency (EE) of free fatty acids was 74.8%. The compositions of the FFA and acylglycerols of the upper oil layer (crude
diacylglycerol) of the reaction mixture were determined using a high temperature gas chromatograph (GC). The crude diacylglycerol
from the selected conditions was molecularly distilled at 170 °C evaporator temperatures to produce a diacylglycerol-enrich
oil (DEO) with a purity of 83.1% and a yield of 42.7%. 相似文献
9.
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
10.
Tiago Simões Francisco Valero Carla Tecelão Suzana Ferreira-Dias 《Journal of the American Oil Chemists' Society》2014,91(3):411-419
This study aims to produce human milk fat substitutes by an acidolysis reaction between lard and the free fatty acids (FFA) from a fish oil concentrate rich in docosahexaenoic acid, in solvent-free media. The immobilized commercial lipases from (1) Rhizomucor miehei (Lipozyme RM IM), (2) Thermomyces lanuginosa (Lipozyme TL IM) and (3) Candida antarctica (Novozym 435) were tested as biocatalyst. Also, the heterologous Rhizopus oryzae lipase (rROL), immobilized in Accurel® MP 1000, was tested as a feasible alternative to the commercial lipases. After 24 h of reaction at 50 °C, similar incorporations of polyunsaturated fatty acids (c.a. 17 mol%) were attained with Novozym 435, Lipozyme RM IM and rROL. The lowest incorporation was achieved with Lipozyme TL IM (7.2 mol%). Modeling acidolysis catalyzed by rROL and optimization of reaction conditions were performed by response surface methodology, as a function of the molar ratio FFA/lard and the temperature. The highest acidolysis activity was achieved at 40 °C at a molar ratio of 3:1, decreasing with both temperature and molar ratio. Operational stability studies for rROL in seven consecutive 24-h batches were carried out. After the fourth batch, the biocatalyst retained about 55 % of the original activity (half-life of 112 h). 相似文献
11.
Achanai Buasri Bussarin Ksapabutr Manop Panapoy Nattawut Chaiyut 《Korean Journal of Chemical Engineering》2012,29(12):1708-1712
A reactor has been developed to produce high quality fatty acid methyl esters (FAME) from waste cooking palm oil (WCO). Continuous transesterification of free fatty acids (FFA) from acidified oil with methanol was carried out using a calcium oxide supported on activated carbon (CaO/AC) as a heterogeneous solid-base catalyst. CaO/AC was prepared according to the conventional incipient-wetness impregnation of aqueous solutions of calcium nitrate (Ca(NO3)2·4H2O) precursors on an activated carbon support from palm shell in a fixed bed reactor with an external diameter of 60 mm and a height of 345 mm. Methanol/oil molar ratio, feed flow rate, catalyst bed height and reaction temperature were evaluated to obtain optimum reaction conditions. The results showed that the FFA conversion increased with increases in alcohol/oil molar ratio, catalyst bed height and temperature, whereas decreased with flow rate and initial water content in feedstock increase. The yield of FAME achieved 94% at the reaction temperature 60 °C, methanol/oil molar ratio of 25: 1 and residence time of 8 h. The physical and chemical properties of the produced methyl ester were determined and compared with the standard specifications. The characteristics of the product under the optimum condition were within the ASTM standard. High quality waste cooking palm oil methyl ester was produced by combination of heterogeneous alkali transesterification and separation processes in a fixed bed reactor. In sum, activated carbon shows potential for transesterification of FFA. 相似文献
12.
Typoselectivity of Crude Geobacillus sp. T1 Lipase Fused with a Cellulose-Binding Domain and Its Use in the Synthesis of Structured Lipids 总被引:1,自引:0,他引:1
Xiao-Li Qin Hui-Hua Huang Dong-Ming Lan Yong-Hua Wang Bo Yang 《Journal of the American Oil Chemists' Society》2014,91(1):55-62
Typoselectivity of crude CBD-T1 lipase (Geobacillus sp. T1 lipase fused with a cellulose binding domain) was investigated. Multi-competitive reaction mixtures including a set of n-chain fatty acids (C8:0, C10:0, C12:0, C14:0, C18:1 n-9, C18:2 n-6 and C18:3 n-3) and tripalmitin-enriched triacylglycerols were studied in hexane. The crude CBD-T1 lipase discriminated strongly against C18:1 n-9 [competitive factor (α) = 0.23] and showed the highest preference for C8:0 (α = 1). Utilizing the catalytic properties of crude CBD-T1 lipase, acidolysis of soybean oil with C8:0 was selected as a model reaction to investigate the ability of the lipase to produce MLM-type (medium-long-medium) structured lipids. Several reaction parameters (added water amount, reaction temperature, substrate molar ratio and reaction time) examined for incorporating C8:0 into soybean oil, the optimum conditions were: 1:3 (soybean oil/C8:0) of molar ratio, 3 mL of hexane, 50 °C of temperature, 48 h of reaction time, 20 % of crude CBD-T1 lipase (w/w total substrates), and 7.5 % of water (w/w enzyme). Under these conditions, the incorporation of C8:0 was 29.6 mol%. The results suggest that crude CBD-T1 lipase, which showed different fatty acid specificity profiles, is a potential biocatalyst for the modification of fats and oils. 相似文献
13.
Purification of docosahexaenoic acid from tuna oil by a two-step enzymatic method: Hydrolysis and selective esterification 总被引:3,自引:0,他引:3
Yuji Shimada Kazuaki Maruyama Akio Sugihara Shigeru Moriyama Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1997,74(11):1441-1446
Purification of docosahexaenoic acid (DHA) was attempted by a two-step enzymatic method that consisted of hydrolysis of tuna
oil and selective esterification of the resulting free fatty acids (FFA). When more than 60% of tuna oil was hydrolyzed with
Pseudomonas sp. lipase (Lipase-AK), the DHA content in the FFA fraction coincided with its content in the original tuna oil. This lipase
showed stronger activity on the DHA ester than on the eicosapentaenoic acid ester and was suitable for preparation of FFA
rich in DHA. When a mixture of 2.5 g tuna oil, 2.5 g water, and 500 units (U) of Lipase-AK per 1 g of the reaction mixture
was stirred at 40°C for 48 h, 83% of DHA in tuna oil was recovered in the FFA fraction at 79% hydrolysis. These fatty acids
were named tuna-FFA-Ps. Selective esterification was then conducted at 30°C for 20 h by stirring a mixture of 4.0 g of tuna-FFA-Ps/lauryl alcohol (1:2, mol/mol), 1.0 g water, and 1,000 U of Rhizopus delemar lipase. As a result, the DHA content in the unesterified FFA fraction could be raised from 24 to 72 wt% in an 83% yield.
To elevate the DHA content further, the FFA were extracted from the reaction mixture with n-hexane and esterified again under the same conditions. The DHA content was raised to 91 wt% in 88% yield by the repeated
esterification. Because selective esterification of fatty acids with lauryl alcohol proceeded most efficiently in a mixture
that contained 20% water, simultaneous reactions during the esterification were analyzed qualitatively. The fatty acid lauryl
esters (L-FA) generated by the esterification were not hydrolyzed. In addition, L-FA were acidolyzed with linoleic acid, but
not with DHA. These results suggest that lauryl DHA was generated only by esterification. 相似文献
14.
Yuji Shimada Norihito Sakai Akio Sugihara Hiroyuki Fujita Yo Honda Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1998,75(11):1539-1544
γ-Linolenic acid (GLA) is a physiologically valuable fatty acid, and is desired as a medicine, but a useful method available
for industrial purification has not been established. Thus, large-scale purification was attempted by a combination of enzymatic
reactions and distillation. An oil containing 45% GLA (GLA45 oil) produced by selective hydrolysis of borage oil was used
as a starting material. GLA45 oil was hydrolyzed at 35°C in a mixture containing 33% water and 250 U/g-reaction mixture of
Pseudomonas sp. lipase; 91.5% hydrolysis was attained after 24 h. Film distillation of the dehydrated reaction mixture separated free
fatty acids (FFA; acid value 199) with a recovery of 94.5%. The FFA were selectively esterified at 30°C for 16 h with two
molar equivalents of lauryl alcohol and 50 U/g of Rhizopus delemar lipase in a mixture containing 20% water. The esterification extent was 52%, and the GLA content in the FFA fraction was
raised to 89.5%. FFA and lauryl esters were not separated by film distillation, but the FFA-rich fraction contaminated with
18% lauryl esters was recovered by simple distillation. To further increase the GLA content, the FFA-rich fraction was selectively
esterified again under similar conditions. As a result, the GLA content in the FFA fraction was raised to 97.3% at 15.2% esterification.
After simple distillation of the reaction mixture, lauryl esters contaminating the FFA-rich fraction were completely eliminated
by urea adduct fractionation. When 10 kg of GLA45 oil was used as a starting material, 2.07 kg of FFA with 98.6% GLA was obtained
with a recovery of 49.4% of the initial content. 相似文献
15.
Yuji Shimada Akio Sugihara Masahiro Shibahiraki Hiroyuki Fujita Hirofumi Nakano Toshihiro Nagao Tadamasa Terai Yoshio Tominaga 《Journal of the American Oil Chemists' Society》1997,74(11):1465-1470
γ-Linolenic acid (GLA) was purified from borage oil by a two-step enzymatic method. The first step involved hydrolysis of
borage oil (GLA content, 22.2 wt%) with lipase, Pseudomonas sp. enzyme (LIPOSAM). A mixture of 3 g borage oil, 2 g water, and 5000 units (U) LIPOSAM was incubated at 35°C with stirring
at 500 rpm. The reaction was 91.5% complete after 24 h. The resulting free fatty acids (FFA) were extracted from the reaction
mixture with n-hexane (GLA content, 22.5 wt%; recovery of GLA, 92.7%). The second step involved selective esterification of borage-FFA with
lauryl alcohol by using Rhizopus delemar lipase. A mixture containing 4 g borage-FFA/lauryl alcohol (1:2, mol/mol), 1 g water, and 1000 U lipase was incubated at
30°C for 20 h with stirring at 500 rpm. Under these conditions, 74.4% of borage-FFA was esterified, and the GLA content in
the FFA fraction was enriched from 22.5 to 70.2 wt% with a recovery of 75.1% of the initial content. To further elevate the
GLA content, unesterified fatty acids were extracted, and esterified again in the same manner. By this repeated esterification,
GLA was purified to 93.7 wt% with a recovery of 67.5% of its initial content. 相似文献
16.
Baran Onal-Ulusoy Eren Tur Mehmet Mutlu 《Journal of the American Oil Chemists' Society》2013,90(11):1653-1659
Sunflower oil was used for deep frying of potatoes at 170 ± 5 °C and for 8 h per day for 5 days in a fryer with an automatic oil filtration system. Three different frying operations were performed: operation (OP)-1, OP-2 and OP-3; that correspond to the oil unfiltered at the end of each frying day, the oil filtered through the fryer's own filter (passive filtration) and the oil firstly subjected to passive filtration and then filtered through a polyethersulfone membrane modified with hexamethyldisiloxane via radio frequency plasma (75 W-5 min, discharge power–time), respectively. The performance of each operation was investigated in terms of free fatty acids (FFA), conjugated dienoic acids (CD), TOTOX value, total polar content (TPC), Hunter color, viscosity, fatty acid composition, and tocopherol content. The results showed that OP-3 could decrease FFA, CD, TOTOX, TPC, L*a*b* value, viscosity and linoleic acid (18:2)/palmitic acid (16:0) ratio in 29.6, 11.7, 25, 30.8, 6.1*11.3*20.8*, 7.8, 12.2 %, respectively, compared to the unfiltered oil (OP-1). Regenerated oil from OP-3 had a frying life approximately 17 h more than oils from both OP-1 and OP-2. 相似文献
17.
Use of an Adsorption Process for Purification of Pollock-Oil-Based Biodiesel Comprises Methyl Esters
Kevin Mis Solval Subramaniam Sathivel 《Journal of the American Oil Chemists' Society》2012,89(9):1713-1721
The quality of biodiesel from crude pollock oil and the effect of a purification process on the physicochemical properties of pollock oil biodiesel were evaluated. Unpurified pollock oil (PO) was transesterified to biodiesel from pollock oil (BPO) using methyl alcohol (1:6 molar ratio) and NaOH (1 % w/w of the oil weight); and the resulting fatty acids methyl esters (FAME) were purified with 10 % (w/w) activated earth to yield purified biodiesel from pollock oil (PBPO). The samples were evaluated for yield, FAME composition, free fatty acids (FFA), peroxides value (PV), moisture, bulk density, cloud point, flash point, free and total glycerin, color, rheological properties, and minerals. BPO and PBPO were evaluated for the kinetics of lipid oxidation. The transesterification and purification processes had no effect on the FAME composition of PO. The yield of PBPO was significantly (P < 0.05) reduced after the transesterification and purification processes. Moreover, the transesterification process significantly (P < 0.05) reduced the FFA, moisture, bulk density, flash point, total glycerides, redness, viscosity, arsenic and silicon content in PO. Meanwhile, the purification process significantly (P < 0.05) reduced the PV, redness, and sulfur content of BPO. The flash point of BPO was significantly (P < 0.05) increased by the purification process from 79 to 84 °C. PO, BPO, and PBPO behaved as non-Newtonian and Newtonian fluids at 0 and 25 °C, respectively. BPO showed a lower oxidation rate and activation energy compared to those of PBPO. BPO and PBPO met the ASTM biodiesel standard D6751 for moisture, bulk density, cloud point, free and total glycerin, Na, P, and S. The study demonstrated that high viscosity crude pollock oil could be converted into low viscosity purified pollock oil biodiesel. 相似文献
18.
Ching-Hung Chen Chieh-Ming J. Chang Shih-Ming Lai 《The Journal of Supercritical Fluids》2010,52(2):228-426
This study investigates supercritical carbon dioxide (SC-CO2) extraction of triglycerides from powdered Jatropha curcas kernels followed by subcritical hydrolysis and supercritical methylation of the extracted SC-CO2 oil to obtain a 98.5% purity level of biodiesel. Effects of the reaction temperature, the reaction time and the solvent to feed ratio on free fatty acids in the hydrolyzed oil and fatty acid esters in the methylated oil via two experimental designs were also examined. Supercritical methylation of the hydrolyzed oil following subcritical hydrolysis of the SC-CO2 extract yielded a methylation reaction conversion of 99%. The activation energy of hydrolysis and trans-esterified reactions were 68.5 and 45.2 kJ/mole, respectively. This study demonstrates that supercritical methylation preceded by subcritical hydrolysis of the SC-CO2 oil is a feasible two-step process in producing biodiesel from powdered Jatropha kernels. 相似文献
19.
Yong Wang Mouming Zhao Shiyi Ou Keke Song Xue Han 《European Journal of Lipid Science and Technology》2009,111(7):652-662
Partial hydrolysis of palm olein catalyzed by phospholipase A1 (Lecitase Ultra) in a solvent‐free system was carried out to produce diacylglycerol (DAG)‐enriched palm olein (DEPO). Four reaction parameters, namely, reaction time (2–10 h), water content (20–60 wt‐% of the oil mass), enzyme load (10–50 U/g of the oil mass), and reaction temperature (30–60 °C), were investigated. The optimal conditions for partial hydrolysis of palm olein catalyzed by Lecitase Ultra were obtained by an orthogonal experiment as follows: 45 °C reaction temperature, 44 wt‐% water content, 8 h reaction time, and an enzyme load of 34 U/g. The upper oil layer of the reaction mixture with an acid value of 54.26 ± 0.86 mg KOH/g was first molecularly distilled at 150 °C to yield a DEPO with 35.51 wt‐% of DAG. The DEPO was distilled again at 250 °C to obtain a DAG oil with 74.52 wt‐% of DAG. The composition of the acylglycerols of palm olein and the DEPO were analyzed and identified by high‐performance liquid chromatography (HPLC) and HPLC/electrospray ionization/mass spectrometry. The released fatty acids from the partial hydrolysis of palm olein catalyzed by phospholipase A1 showed a higher saturated fatty acid content than that of the raw material. 相似文献
20.
Continuous Hydrolysis of Cuphea Seed Oil in Subcritical Water 总被引:1,自引:0,他引:1
Eller Fred J. Teel J. A. Palmquist D. E. 《Journal of the American Oil Chemists' Society》2011,88(9):1455-1461
Cuphea seed oil (CSO) is a source of decanoic acid which is useful in the preparation of estolide lubricants among other applications.
Decanoic acid and other free fatty acids (FFA) can be hydrolyzed from CSO using a catalyst like KOH, followed by neutralization
with HCl and extraction with hexane. This procedure, however, uses caustic materials, hazardous solvents and generates waste
salt streams. This study investigated the use of water without catalysts to hydrolyze CSO in a continuous flow tubular reactor.
Parameters such as the interaction of pressure and temperature, temperature, water to cuphea oil fatty acid residue (H2O:COFAR) molar ratio, and flow rate were examined. The lowest conversions of CSO to FFA were at the lowest temperature (i.e.,
300 °C) and the hydrolysis was ca. 90% at 350 °C and 13.8 MPa and ca. 80% at 365 °C and 13.8 MPa. Hydrolysis increased with
pressure and leveled off at 13.8 MPa. Hydrolysis increased with temperature and leveled off at ca. 330 °C. The optimal H2O:COFAR molar ratio was found to be 6:1. Conversion rates were inversely proportional to flow rate with 95% conversion at
the lowest flow rate (i.e., 0.25 mL/min) corresponding to the longest residence time (i.e., ca. 45.2 min). These results demonstrate
a continuous subcritical water process for hydrolyzing CSO to FFA that is effective, requires no catalysts and does not generate
a waste salt stream. 相似文献