Continuous production of biosurfactant with foam fractionation

A glucose‐limited chemostat was used to determine the growth parameters of BBK006 for continuous production of the biosurfactant surfactin. The continuous cultivation exhibited low maintenance metabolism (m = 0.39 mmol_glucose g_bacteria^?1 h^?1) and high molar growth yield ( g_bacteria mol_glucose^?1). It was found that the surfactin production rate in continuous culture was not only a function of dilution rate but also varied with the initial concentration of glucose in the feed. A high steady state concentration of surfactin (18 mg L^?1) was maintained in the culture at a dilution rate of 0.2 h^?1 when glucose concentration in the feed was 0.25 g L^?1. This is the first demonstration of continuous surfactin production and recovery using glucose as a carbon source. The production of surfactin is known to be related to the age of the microorganisms and a simple mathematical model has been constructed to show how the age‐related production can be quantified. Copyright © 2006 Society of Chemical Industry     

Characterization of chilean hazelnut (Gevuina avellana mol) seed oil

The fatty acid composition, tocopherol and tocotrienol content, and oxidative stability of petroleum benzene-extracted Gevuina avellana Mol (Proteaceae) seed oil were determined. Positional isomers of monounsaturated fatty acids were elucidated by gas chromatography-electron impact mass spectrometry after 2-alkenyl-4,4-dimethyloxazoline derivatization. This stable oil (Rancimat induction period at 110°C: 20 h) is composed of more than 85% monounsaturated fatty acids and about equal amounts (6%) of saturated and polyunsaturated (principally linoleic) fatty acids. Unusual positional isomers of monounsaturated fatty acids, i.e., C_16:1 Δ¹¹, C_18:1 Δ¹², C_20:1 Δ¹¹, C_20:1 Δ¹⁵, C_22:1 Δ¹⁷, and presumably C_22:1 Δ¹⁹ were identified. The C_18:1 Δ¹² and C_22:1 Δ¹⁹ fatty acids are described for the first time in G. avellana seed oil. While only minute quantities of α-, γ-tocopherols and β-, γ- and δ-tocotrienols were found, the oil contained a substantial amount of α-tocotrienol (130 mg/kg). The potential nutritional value of G. avellana seed oil is discussed on the basis of its composition.     

润滑油糠醛精制装置优化运行措施

对糠醛抽提装置生产中存在的问题进行原因分析,提出具体的解决方法,实施后效果较明显.     

Continuous fractionation of multicomponent mixtures with sequential centrifugal partition chromatography

The applicability of sequential centrifugal partition chromatography for continuous fractionation of multicomponent mixtures, represented here by a mixture of four parabens with very similar molecular structure, was studied. The fractionation of the quaternary feed mixture was regarded as a separation of a pseudo‐binary mixture. The model‐based approach was used to select the biphasic liquid system and the unit operating parameters. All desired fractions were recovered with purities >99%. The influence of the solute concentration on the density, viscosity and volume ratio of the phases as well as on the partitioning of the solutes between the two phases was investigated. According to these results, possibilities for increasing the throughput were proposed and validated experimentally. For example, butyl paraben with a purity ≥99% was continuously separated from the rest of the parabens in a 250 mL unit with a throughput of 3.24 g h^?1 and a solvent consumption of 0.33 L g^?1. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1659–1673, 2017     

Crystalline fractionation of hydrogenated sunflowerseed oil

Crystalline fractionation of hydrogenated sunflowerseed oil was performed and the chemical composition of the separated fractions at different temperatures was determined. The results show that the triglycerides obtained after a short retention time (less than 16.4 min) were enriched in the low-temperature fractions (lower than 22°C), the triglycerides of long retention time (more than 21.5 min) were concentrated in the higher-temperature fractions (higher than 30°C), and the triglycerides of medium retention time (between 16.4 and 21.5 min) were concentrated in the medium-temperature fractions (22°C to 30°C). The partition ratio of triglycerides with retention times of 8.8, 12.5, 16.5, 21.5 and 29.1 minutes was increased as a function of the fractionation temperature.     

溶剂辅助糠醛精制废润滑油

研究了用溶剂辅助糠醛精制废润滑油,提高润滑油的收率,同时改善了产品质量.通过筛选得出助溶剂正丁醇的最佳加入量,考察了精制温度和剂油比对产物收率的影响.对产物进行性质测定结果表明:在糠醛溶剂中加入15%(正丁醇:糠醛)的正丁醇、精制温度85℃和剂油比为2:1的条件下,得到再生后润滑油基础油为澄清淡黄色,产物收率为88.5...     

Continuous fractionation of used frying oil by supercritical CO<Subscript>2</Subscript>

Fractionation by supercritical carbon dioxide (SC−CO₂) might be a way to purify used frying oils, since a selective separation of the oil components based on their polarity and M.W. can be attained. In this work, we studied the purification of peanut oil used for frying by SC−CO₂ continuous fractionation in a packed column. The influence of pressure (15–35 MPa) and temperature (25–55°C) on the yield and on the composition of products was determined. The composition of the top and bottom products was evaluated by using size-exclusion chromatography and other accepted chemical methods. Process conditions were selected to separate TG from degraded compounds. Experimental results indicated that the operating conditions leading to maximal TG recovery in the extract were 35 MPa, 55°C, and a solvent-to-feed ratio of 53. By operating at these conditions, it was possible to recover 97% of the TG placed on the column and about 52% by weight of the used frying oil. The composition of the purified top stream was very similar to that of fresh frying oil.     

减五线脱蜡油NMP精制与糠醛精制研究

用沈北、大庆混合脱蜡油为原料,进行NMP溶剂精制和糠醛溶剂精制的对比研究。在实验确定了NMP和糠醛溶剂与减五线脱蜡油临界溶解度曲线的基础上,NMP精制采用正交设计法考察溶剂比、溶剂含水量及抽提温度等因素的影响,糠醛精制主要考察了剂油比和抽提温度的影响,采用多元二次回归方程式回归了精制油收率及质量与操作因素的关系,用非线性回归确定出满足粘度指数≥95的要求,收率最大的适宜操作条件。NMP精制最优操作条件为:剂油体积比4.0,抽提温度60℃,溶剂含水量0%,在此操作条件下,精制油的收率为63%;糠醛精制最优操作条件为:剂油比4.5(V/V),抽提温度110℃,此条件下精制油的收率为52%。说明NMP溶剂相对糠醛溶剂具有良好的溶解能力及选择性。     

大庆和涠洲混炼油糠醛精制研究

以大庆和涠洲混炼油(体积比为1∶1)减二线脱蜡油为原料,糠醛为溶剂,考察了剂油比、抽提温度对润滑油基础油糠醛精制效果的影响。实验表明,精制油的粘度指数随剂油比的增加和精制温度的上升而增大,精制油的收率随剂油比的增加和精制温度的上升而下降。当温度增大到一定程度时,精制油收率有变化,而粘度指数与折光率基本不变。     

糠醛精制抽出油中多环芳烃脱除试验研究

利用糠醛和助剂,对克拉玛依减四线糠醛抽出油中多环芳烃进行了单级抽提试验研究。采用单因素试验考察了剂油比、抽提温度、助剂用量、抽提时间及沉降时间对精制油收率及多环芳烃含量的影响。研究结果表明：抽提时间和沉降时间对精制油收率和多环芳烃含量的影响较小,当两者均为20min时,抽提基本达到平衡;增大剂油比、提高抽提温度、加大助剂用量均会降低精制油多环芳烃含量;在助剂用量25％、抽提温度55℃、抽提时间和沉降时间均为20min的条件下,当剂油比（质量比）达到5时,精制油中多环芳烃质量分数小于3％,符合欧盟对橡胶填充油的环保要求。     

糠醛精制法生产变压器油的工艺研究

以兰炼常减压装置减一线去蜡油为原料(新疆原油),采用糠醛为溶剂,考察温度梯度、剂油比、含水量、萃取段数与精制油产品之间的关系。结果表明,合适的生产变压器油的工艺参数为:温度梯度40℃,剂油比为(3.0～4.0)∶1,含水量<0.5%,萃取段数不低于3段。     

Separation of oil contaminants by surfactant-aided foam fractionation

The separation of oily contaminants out of aqueous/non-aqueous phases using foam fractionation with a surfactant was investigated. In the separation of the light oil (hexadecane), the eluted amount of oil and the o/w (oil/water) ratio increased with the weight percentage of SDS (sodium dodecyl sulfate); and the ratio actually remained the same above the CMC (critical micelle concentration) point (0.23 wt% of SDS). Most of the oil was eluted even at 49:1 initial o/w ratio with the surfactant. For the heavy oil (carbon tetrachloride), the eluted o/w ratio and the oil recovery had maxima at 0.05 and 0.1 wt% of SDS solution, respectively, even though the overall recovery of 20–30 % was much lower than that of 80–100 % in the light oil. It was speculated that emulsion formation might affect oil entrapment in the foams. Higher gas flow rates, in general, increased the oil recovery, but did not increase the o/w ratio in the effluents.     

Glyceride analysis of palm oil after solvent fractionation

A procedure is described for determing the triglyceride composition of palm oil and its fractions by the use of silver nitrate thin layer chromatography (TLC) and gas liquid chromatography (GLC). The triglycerides separated by silver nitrate TLC according to the number of double bonds are quantified using infrared spectroscopy before further analysis by GLC according to carbon number. The results from the two techniques enable the composition of the oil and fractions to be computed on a molecular basis in relation to fatty acid types. The potential application of this procedure is to analyze fractions obtained from the fractionation of oils and fats to which the 1,3-Random-2-Random distribution theory is not applicable.     

Supercritical fluid fractionation of thermally oxidized canola oil

Supercritical fluid extraction procedures were developed to fractionate thermally oxidized canola oil. Canola oil was heated in a sealed glass ampoule for 72 h at 200°C in a forced-convection oven. After heating, the percentages of triacylglycerol (TAG) trimer, dimer, monomer and lowermolecular weight (LMW) compounds in the heated oil sample (as determined by high-performance size-exclusion chromatography) were 3.0, 8.4, 81.3 and 7.3%, respectively. The LMW compounds included diacylglycerols, monoacylglycerols and free fatty acids. Fractions of TAG monomer of approximately 98% purity were isolated after extraction at 408 atm for 45 min. After a second extraction at 442 atm for 45 min, a TAG dimer fraction of 95% purity was isolated. Recoveries of TAG monomer and dimer were 96 and 87%, respectively.     

Dry fractionation of coconut oil by melt crystallization

Layer melt crystallization was applied for the dry fractionation of multi-component mixtures using coconut oil as a model substance. The aim of the experiments was to optimize the crystallization parameters (e.g. crystallization temperature, melt temperature, cooling rate, agitation speed) in order to obtain the solid fraction with a higher melting temperature and solid fat properties. The isothermal crystallization behavior of coconut oil was investigated via differential scanning calorimetry (DSC). The efficiency of the crystallization process was monitored by determining the melting point and solid fat content (SFC) of the fractionated products. The morphology of crystal layer was studied by a light microscope. Cool finger temperature was found to have the greatest impact on product properties. Applying a cooling rate of 0.2 K/h resulted in sufficient growth rates providing the required products. The micrographs of the solid fraction revealed lamellar particle arrangement compared to coconut oil possessing spherulites.     

Continuous slurry hydrogenation of soybean oil with nickel catalysts

Soybean oil was hydrogenated continuously in the presence of nickel catalysts. The iodine value of the products was varied by changing the oil flow rate and temperature of the reaction. Sulfur-promoted nickel catalyst increased the selectivity for linolenate hydrogenation, but formed much higher proportions oftrans isomers. Linoleate selectivity improved with temperature with both nickel and sulfur-promoted nickel catalysts, buttrans isomerization also increased. The feasibility of this continuous reactor system was demonstrated as a practical means to prepare hydrogenated stocks of desired composition and physical characteristics at high throughput.     

Continuous recovery of acid oil

A continuous process for acidulation of all types of caustic soapstocks is described. The soap is diluted, heated, acidulated and centrifuged to yield three products: acid oil, acid water and a sludge phase. Typical performance data on various grades of soapstocks and the recovered products are given.     

Isopropanol fractionation of butter oil and characteristics of fractions

Fractionation of butter oil from isopropanol and characterization of the chemical composition and the melting properties of the fractions obtained have been investigated. Butter oil was fractionated from isopropanol (1∶4 wt/vol) at 15 to 30°C. The yields of stearins and oleins were dependent on the temperature employed during fractionation. Thus, 24.8 to 48.9% of stearins and 51.5 to 75.2% of oleins could be obtained as the crystallization temperature varied from 15 to 30°C. The stearin fractions displayed a distinct variation in the fatty acid compositions. The palmitic acid content of the stearin fractions varied from 39.1 to 44.0%, and that of stearic from 15.1 to 16.8%, respectively. The olein fractions contained 43.2% stearic acid, and 2.4 to 2.8% palmitoleic acid (C16∶1). The solid fat content values of the stearin fractions obtained were 62–67, 39–50, and 21–25 at 10, 20, and 30°C, respectively. From the results, it is evident that anhydrous milk fat can be fractionated at relatively high temperatures from isopropanol to produce stearin and olein fractions of specific composition and properties.     

A critical evaluation of thermal fractionation of butter oil

Butter was fractionated on the basis of temperature (17–29°C) without agitation using slow cooling of melted anhydrous fat in conjunction with gentle vaccum filtration to produce four solid and four liquid fractions. Each of the fractions was analyzed for fatty acid composition, triglyceride profile, and characterized by gel permeation high performance liquid chromatography and differential scanning calorimetry thermograms. Fatty acid analysis indicated that the solid fractions had slightly higher amounts of palmitic and stearic acid and lower levels of oleic acid, while the remaining analyses did not indicate any substantial compositional differences between the fractions. Although the 29°C solid fraction (∼10%) could be said to be somewhat unique, the natural variation in the normal seasonal composition of butterfat was almost equal to that obtained by fractionation. The experimental physicochemical data obtained for the fractions in this study extend and verify previous work on butteroil fractionation, and indicate that thermal fractionation has marginal merit. On the other hand, literature describing more positive thermal butteroil fractionation results obtained by the properietary Tirtiaux process (Fleurus, Belgium), indictes that it may be a more expedient avenue to explore and let market forces determine whether fractionation has a future in Canada and North America.     

Liquid Chromatographic fractionation of oil-sand and crude oil asphaltenes

Asphaltenes extracted from Alberta oil sands (Athabasca, Cold Lake, and Peace River) and crude oils (Taber South and Fenn-Big Valley) were fractionated by sequential elution solvent chromatography (SESC) involving 10 organic solvents on a silica column. Athabasca asphaltenes and SESC fractions were further studied by elemental analysis, i.r., u.v., and n.m.r. spectroscopy. Incomplete extraction of maltenes from the oil-sand bitumens increased the yields of the first two SESC fractions, the saturates and aromatics, of oil-sand asphaltenes relative to the crude oil asphaltenes. About 55 wt% of the asphaltenes elute in fractions 3–5. Two distinct molecular types are present in the asphaltenes; namely, lower functionality species with lower heteroatom content and the higher functionality species with higher heteroatom content. Compounds eluting in fractions 3–10 are predominantly polynuclear aromatics with alkyl substituants and probably bridged by cycloalkanes. The extent of bridging as well as the location, number and type of heteroatoms determines the fraction in which each compound appears. Complexity of compounds eluting increases with time: earlier fractions are composed of smaller-size polynuclear aromatic centers and contain heteroatoms in predominantly ring locations, whereas later fractions contain a larger proportion of complex species and more functional heteroatom groups.