Rate of color formation in sulfonation of dodecylbenzene with gaseous sulfur trioxide

An experimental method has been developed to study the color formation in sulfonation of dodecylbenzene with gaseous sulfur trioxide. The rate of color formation in dodecylbenzene sulfonation, measured as the light absorbance at 420 nm, has been studied under various conditions, and the results have been correlated to a mathematical model.     

磺化SEBS的制备工艺研究

探究了影响SEBS磺化反应的各种因素。结果表明:较适宜的磺化试剂和溶剂分别为乙酰基磺酸酯和三氯甲烷;随着磺化反应时间的延长和磺化试剂用量的增加,产物磺化度均有不同程度的增大,达到一定程度后,磺化反应趋于平稳;低温反应的平衡磺化度高于高温反应的平衡磺化度,但平衡时间过长;磺化试剂配比n (乙酸酐)∶n (浓硫酸)=2∶1时,产物磺化度达到最大。当磺化试剂配比大于或小于2∶1时,磺化效率均有不同程度的降低。     

超临界CO2萃取与水蒸气蒸馏提取姜油的GC-MS分析

采用超临界CO2萃取和水蒸气蒸馏法提取姜油,用气相色谱-质谱联用技术鉴定了两种提取方法所得姜油的化学成分并进行了分析比较。结果显示:超临界CO2流体萃取法的姜油得率约为水蒸气蒸馏法的3.8倍,提取时间短,温度低,特别是得到了含量较高为12.82％的主要有效成分之一6-姜酚,而在水蒸气蒸馏法得到的姜油中则未见。     

水蒸气蒸馏提取萼翅藤叶挥发油工艺研究

采用水蒸气蒸馏法提取萼翅藤叶挥发油,以挥发油得率为指标,用正交实验,考察浸泡时间、提取时间、加水量3个因素对挥发油提取率的影响。结果表明,最佳提取条件为:加入5倍于原料质量的水,浸泡4 h,水蒸气蒸馏6 h,挥发油提取量最大,可达0.35%。     

超临界CO2和微波辅助萃取辽细辛挥发油

通过超临界CO2萃取辽细辛挥发油均匀设计实验和微波诱导萃取的正交实验比较,考察了影响提取的主要因素,得到了最佳萃取工艺. 超临界CO2萃取最佳工艺条件为：压力16 MPa,温度32oC,CO2流量20 kg/h和时间80 min,得率为3.78%;微波萃取最佳工艺条件为：辐射功率720 W,辐射时间50 s,溶剂用量300 ml,洗涤溶剂用量30 ml,得率为5.46%. 水蒸馏法提取率为1.62%. 结果表明,超临界CO2和水蒸馏法萃取辽细辛挥发油品质最好;微波萃取收率最高,但品质较差.     

超临界CO_2萃取青皮挥发油的工艺研究

采用正交实验法对超临界CO2萃取中药青皮挥发油的最佳工艺条件进行优选。以挥发油得率为考察指标,探讨了萃取压力、萃取温度、萃取时间三因素在不同水平下对青皮挥发油得率的影响,并与水蒸气蒸馏法进行了比较。研究表明,萃取压力对挥发油得率有显著影响,萃取温度及时间影响不显著,各因素作用主次关系为:压力>温度>时间。优选得到的最佳工艺为:萃取压力25 MPa,萃取温度35℃,萃取时间1.5 h,得率为1.3197%,比水蒸气蒸馏法提高2.4倍,时间减少78.57%。超临界CO2萃取收率高、耗时短、品质好。     

Removal of naphthenic acids from a vacuum fraction oil with an ammonia solution of ethylene glycol

A new method to remove and purify the naphthenic acids in heavy fractions of petroleum is studied in this paper. An ammonia solution of ethylene glycol was used as the acid removal reagent by mixing with the petroleum fraction and then allowing the two phases to separate, with the naphthenic acids being extracted from petroleum fractions. The naphthenic acids were recovered by heating the ammonia solution containing naphthenic acids to release NH₃ and decompose the naphthenic acid ammonia salt. Petroleum ether was used to purify the naphthenic acids by extracting the neutral oils from the acid removal reagent. Data indicated that the optimal extraction temperature was in the range of 50–60 °C and the optimal NH₃ content in ethylene glycol was 3–5%. The contact time should be more than 10 min with the reagent/oil ratio being more than 0.3 (wt/wt). Acid removal can be greater than 85%. After purification by petroleum ether, the purity of naphthenic acids can be greater than 90%.     

烷基苯的磺化研究

烷基苯的磺化是制造阴离子表面活性剂的关键工序之一。本文重点介绍了采用国内消化吸收的意胡利Ｂａｌｌｅｓｔｒａ公司多管膜多磺化法生产烷基苯碘酸的技术，该技术工艺流程合理，设备结构简单，能耗低，产品质量好，不但适应于烷基苯的磺化，还可用于脂肪醇，脂肪醇聚氧乙烯醚等多种原料的磺化。     

Monitoring the linear alkylbenzene sulfonation process using high-temperature gas chromatography

Controlling the linear alkylbenzene sulfonate (LAS) sulfonation process is a critical part of the LAS manufacturing process; this process can be monitored by assaying for LAS content, unsulfonated linear alkylbenzene (LAB), and LAB sulfones. Traditionally, assaying the LAB and LAB sulfone contents has been time consuming and not straightforward. A simple and rapid procedure is described for the isolation and simultaneous capillary gas chromatographic (GC) quantification of LAB and LAB sulfones in LAS. The procedure involves extraction of the unsulfonated LAB and the LAB sulfones into n-heptane; sodium linear alkylbenzenesulfonate or linear alkylbenzenesulfonic acid (reacted to form sodium linear alkylbenzenesulfonate) remains in the aqueous extraction solvent layer. High-temperature capillary GC using a specialty metal capillary column enables both LAB and high molecular weight LAB sulfones to be quantified.     

柴油中碱性氮化物脱除的研究

采用PS复合溶剂脱除催化柴油中的碱性氮化物，以改善催化柴油的质量和储存安定性；考察了精制溶剂组成、剂油比、精制温度、反应时间及静置时间对脱碱氮的影响。实验结果表明，采用V（甲醇）：V（二甲基亚砜）：V（聚丙烯酰胺）：V（NaOH溶液）=2：1：0．5：6．5，复配的复合溶剂作为络合溶剂、络合时间3min、剂油比0．02、络合温度为室温时效果最佳，精制后的柴油，色度由25下降为14，碱氮脱除率达到92．30％。精制后的催柴油品颜色和氧化安定性得到了显著提高。     

Laboratory investigations on the extraction of oil from vegetable oil-cakes with ethanol

1. Undue dilution of alcohol can be prevented by employing oleaginous materials of moisture content less than 1.0% for ethanol extraction.
2. The residual oil content of the meal depends on the particle size of the cake for a constant period of extraction.
3. Better quality oil in respect to color and F.F.A. is obtained with 95.6% ethanol extraction though the temperature of extraction is higher than the temperature employed with 98.6% ethanol.
4. F.F.A. of the extracted oils is low and within 1.0% for most of the oils, hence a reduction of refining loss. The color of safflower and peanut oils compares with the color of the screw-press oils.
5. In the case of cottonseed meats extraction, the cooking of meats results in a lighter color oil and increases the yield for the same period of extraction. Cottonseed extraction also illustrates the advantages of ethanol as the solvent for oil extraction.

     

Rice brain oil. I. Oil obtained by solvent extraction

1. Freshly milled rice bran has been extracted with commercial hexane and the recovered oil and extracted meal examined for their respective content of wax. The oils were refined and bleached by standards as well as several special methods. The crude, caustic soda refined, and several refined and bleached oils were examined spectrophotometrically.
2. When freshly milled rice bran of good quality is extracted with commercial hexane, an oil of relatively low free fatty acid content is obtained. This oil possesses good color and is as stable as other similar types of crude oils.
3. If the oils is extracted from the brain at a temperature below about 10°C. and the extraction is discontinued at the right time, the extracted oil represents 90–95% of the total lipids in the brain and contains very little wax. This wax, which is readily extracted with hot commercial hexane as well as other types of solvents, amounts to about 3–9% of the total extractable lipids.
4. When subjected to ordinary caustic soda refining methods, good rice brain oils behave much like cottonseed oils of comparable free fatty acid content. Both caustic soda refining in a hydrocarbon solvent and refining with sodium carbonate result in refining losses approximating the absolute or Wesson loss.
5. Some of the refined oils when bleached according to usual practice produce products acceptable for use in the edible trade. However, refined rice bran oil has a definitely greenish cast resulting from the presence of chlorophyll, but this color can be removed by bleaching with a small amount of activated acidic clay.

     

不同方法提取随手香挥发油的对比

目的分析不同方法提取随手香中挥发油的效果。方法采用水蒸气蒸馏法和超声萃取法提取随手香中挥发油,用气象色谱-质谱(GC-MS)分离鉴定了其成分并测定了各成分相对质量分数。结果水蒸气蒸馏法挥发油提取率为2.92%,分别鉴定出45种化合物,占峰面积的89.8%,其中草蒿脑含量最高;超声萃取法挥发油提取率为1.9%,分别鉴定出60种化合物,占峰面积的90.54%,超声波萃取提取其中卅一烷含量最高。结论 2种提取方法提取的挥发油的组成有差异。     

Prepress-solvent extraction of cottonseed,processing conditions and characteristics of products

Summary A study has been made of the relation between processing conditions and the chemical characteristics of cottonseed meals and oils produced by prepressing-solvent extraction. Twenty-six complete sets of mill samples of known processing history and representative of the production at 11 mills were used in the investigation. Cooking conditions were the major factor influencing the distribution of the gossypol between the meal and oil. Reduction in free gossypol during cooking was due to binding with meal components while that occurring during prepressing and solvent extraction resulted mainly from removal of gossypol in the prepressed and solvent-extracted oils. Nitrogen solubility data, which have been suggested as a measure of protein damage, indicated that the major change or reduction in nitrogen solubility occurred during cooking. Very little reduction was noted for prepressing or solvent extraction. The reduction in nitrogen solubility during prepressing is much smaller than that previously reported for normal screw-pressing operations. Prepressed oils gave lower refining losses and lower refined and bleached color than did the solvent-extracted oils. Bleach color reversion, after storage of crude oils for 30 days at 100°F., was greater for solvent-extracted than for prepressed oils. A number of meals exhibited the desirable characteristics of low free gossypol content and high nitrogen solubility. Values calculated for chemical indexes of protein quality, as suggested by Lyman and associates (11), indicate that many of the meals should have good protein quality. Presented at the 45th Annual Meeting of the American Oil Chemists' Society, April 11–14, 1954, San Antonio, Tex. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

Quality of virgin olive oil extracted with the new centrifugation system using a two-phases decanter

Research has been carried out to determine the quality of oil extracted with the new centrifugation system adopting a two-phases decanter. The quality has also been compared with that of oil extracted with the current centrifugation system using a three-phases decanter. Tests were performed in an industrial oil mill, that was equipped with two- and three-phases decanters. Results obtained show that oil extracted with the two different decanters do not differ in free fatty acids, peroxide value, and ultraviolet absorption. On the contrary, the polyphenol and o-diphenol contents are higher in oils obtained with the new centrifugation system than those of oils from the current centrifugation system. For this reason oils obtained with the new extraction system show an increased resistance to autoxidation.     

间壁塔萃取精馏制取植物油抽提溶剂的研究

针对植物油抽提溶剂萃取精馏系统存在的萃取剂结焦问题展开研究,分析了萃取剂结焦的原因,提出了间壁塔萃取精馏制取植物油抽提溶剂的思路,并应用工艺模拟软件对比了间壁塔萃取精馏工艺和常规精馏工艺。模拟结果表明,间壁塔主塔合适的理论塔板数为30,侧线塔塔板数为10,剂油比为1.1(体积比),侧线采出位置为第27块板。与常规两塔精馏相比,再沸器热负荷降低约10%,冷凝器热负荷降低15%,且设备投资也有所减少。     

Quality differences between pre‐pressed and solvent extracted rapeseed oil

Most seed oils are obtained by pre‐pressing the crushed seeds followed by solvent extraction of oil from the press cake. The prepressed oil will contain no solvent residues, and is moreover expected to contain more nutritionally valuable compounds, which can in turn enhance the oxidative stability of the oil. However, reports on differences between extracted and pressed oils are scarce. Therefore, in this study, for a case study on rapeseed oil, the composition and quality were systematically compared between pre‐pressed and solvent extracted oil. In the extracted oil, solvent residues and a clear sensory difference were detected, which disappeared almost completely during refining. The crude oils had a high content in free fatty acids and in primary and secondary oxidation products, which were higher in the extracted than in the pressed oil. However, surprisingly, also the content of minor compounds was slightly higher in the extracted oil than in the pressed oil. This can be explained by a selective extraction of those compounds into the solvent. During refining, a difference between pressed and extracted oils still existed but was less pronounced. The slight difference in antioxidants content might explain the higher oxidative stability of extracted over pressed oils. Practical applications : Traditionally, high yields of vegetable oils are obtained by pre‐pressing the seeds, followed by solvent extraction of the residual oil from the press cake. The solvent extraction leads to higher oil yields, but is expected to affect the composition and quality of the oil, and has moreover negative environmental impacts. In this study, the solvent extracted oil contained slightly higher levels of tocopherols and phytosterols, and had slightly higher oxidative stability, which are desirable quality aspects. In contrast, the solvent extracted oil contained also higher levels of undesirable phospholipids, as well as solvent residues, which were, however, removed during degumming and deodorization, respectively. These results suggest that the final quality of refined pre‐pressed and solvent extracted oils is comparable from nutritional and safety point of view. A choice for pressing instead of solvent extraction will, therefore, rather be driven by sustainability concerns than by nutritional aspects.     

柠檬香茅精油的提取及抗氧化活性研究

文中采用水蒸汽蒸馏法对海南产柠檬香茅进行精油提取,研究了提取时间、料液比、香茅粗细、香茅部位、提取液成分等因素对精油收率及主要成分存在影响,精油提取率为0.09-1.06%,50g 长2cm的干柠檬香茅在1400mL含8 g NaCl的水溶液,提取时间180min时精油出油率最高,为1.06%;随提取条件不同,精油成分有所变化,但主要成分无明显差异,主要为芳樟醇、橙花醛、香叶醛、香叶醇和香叶酸,此五种主要成分的含量约占精油总量的86-96%。电子自旋共振法（ESR）测试结果表明1%香茅精油乙醇溶液对羟基自由基具有一定清除活性,清除率32%。     

植物精油提取新技术的研究进展

随着化工分离技术研究的不断深入,植物精油的提取技术也得到了进一步发展,出现了很多新的提取技术和方法。介绍了植物精油的提取技术,包括超临界CO~2萃取、连续亚临界萃取、微波萃取、微胶囊双水相萃取、超声波萃取、分子蒸馏、酶法提取等方法,对这些技术进行了分析,同时展望了植物精油提取技术的发展前景。     

Subcritical water extraction of essential oil from Aquilaria malaccensis leaves

ABSTRACT

Hydro-distillation (HD) has been widely used in the extraction of essential oil, yet it is a low efficient method that consumes time and energy. In this work, A. malaccensis’ oils have been extracted using subcritical water extraction (SCWE) from its leaves to determine the optimum parameters using analysis of variance. Quadratic model was deduced to be most suitable to analyze SCWE parameters. Regression analysis indicated that interaction of temperature and reaction time parameters exerted great influence on the yield. Kinetic modeling was conducted to study SCWE’s mechanism, and second-order model was concluded to be the best model for SCWE. Optimum extraction conditions of essential oil were 156°C, 0.2 w/w, 25 min. Gas chromatography/mass spectroscopy characterization was conducted and results indicated that the quality of A. malaccensis’ leaves oils extracted by SCWE significantly improved compared to previous studies. Additionally, the essential oils extracted by SCWE contained several value-added compounds useful in medicine such as furfural and guaiacol. Fourier transform infrared, scanning electron microscopy, and Brunauer–Emmett–Teller and Barrett–Joyner–Halenda on the leaves samples provided further evidence for better performance of SCWE, as the sample’s pores, cell walls, cellulose, and hemicellulose were more damaged. The result showed that compared to extraction yield of HD method, that of SCWE was 2.5 times higher, while the requiring time was 8.4 times shorter. Therefore, it was concluded that SCWE is a better extraction method in terms of time, efficiency, yield, and quality.