共查询到20条相似文献,搜索用时 62 毫秒
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选取四川、贵州和福建三地烟草为原料,用水中蒸馏法提取烟草精油。采用气相色谱-质谱联用(GC-MS)仪对不同产地烟草精油的组成及含量进行分析,比较了不同产地对产物产率及组成的影响。研究结果表明:产自福建、四川和贵州的烟草平均得率分别为0.1391%、0.0851%和0.1075%,相应的新植二烯分别为39.86%、36.12%和44.88%。对比分析显示:产自福建的烟草得油率最高,特征香气适中;产自贵州的烟草精油得油率适中,烟草香气突出,有明显甘草香气;产自四川的烟草精油得油率较低,香气较弱。 相似文献
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杉木根精油化学成分研究 总被引:6,自引:0,他引:6
采用常压水蒸气蒸馏法提取了杉木根精油,其得率为1.9-2.3%,密度为0.8580-0.8710,折光率(20℃)为1. 4745、旋光度+0.5°。用GC、IR、NMR、GC-MS等方法对该油进行了定性定量分析。在分出的 112个色谱峰(占该精油总量的 96. 87%)中共鉴定出 52个化合物(占精油总量的 89%),其中含有 α-蒎烯、柠檬烯、对伞花烃、α-松油醇、α-柏木烯、α-白菖烯及β-榄香烯等,其主要成分为柏木醇(39.48%)。 相似文献
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使用湿式减压蒸馏法分离轧钢含油污泥的油分和残渣。采用二次通用旋转组合设计实验,研究了温度、真空度和水蒸气流量对分离效果的影响。结果表明,相比于简单蒸馏,湿式减压蒸馏能显著减轻对油分的破坏,提高油分回收率。在实验参数范围内,当蒸馏温度为321.4℃、真空度为90 kPa、水蒸气流量为1 ml·min−1时,获得最大油分回收率(57.2%)。回收油分时,过高的温度和水蒸气分压会破坏油分,前者促进油分胶质组分向芳香烃和饱和烃转化,后者则会促进脂类水解,并与Fe2O3作用氧化重质油组分,促进胶质组分向芳香烃转化。而对于蒸馏残渣中难以分离的沥青质等大分子有机物,可通过提高温度和水蒸气流量,特别是可以提高温度,促使其分解炭化,以获得较低的残渣含油率,便于残渣中铁金属元素的回收利用。 相似文献
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Mehrez Romdhane Chedly Tizaoui 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(7):759-766
A simplified model that considered the oil constituents as one constituent, anethole, the major component, was used to describe the mass transfer of steam extraction of aniseed essential oil. The model can be used to optimise and control the process. Depending on the oil content, two mass transfer regimes were identified (i) the first one corresponds to an unsaturated surface extraction and (ii) the second corresponds to the slower transfer of oil from the deeper parts of the material to the surface, which may be due to concentration gradients and chemical bonding. The model was validated by experimental data obtained from a pilot‐plant system. Solid‐steam mass transfer coefficients were determined and a critical oil content was found to limit the two mass transfer regimes. The value for this critical oil concentration (xB) was found to be 0.011 (g oil g?1 solid). In addition, an optimal operating pressure of 200 kPa was found to give maximum extraction yield. Copyright © 2005 Society of Chemical Industry 相似文献
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Giane R. Stuart Daíse Lopes J. Vladimir Oliveira 《Journal of the American Oil Chemists' Society》2001,78(10):1041-1044
The deterpenation of orange peel oil in most industries is accomplished by vacuum distillation, but surprisingly little information
on this matter can be found in the open literature. This work reports recent results on orange peel oil deterpenation carried
out in an automatic vacuum distillation column operated in the semibatch mode at the temperatures of 50, 65, and 80°C, at
10, 20, and 30 mbar, and with reflux ratios of 0.25, 0.50, and 0.75. The concentrates were analyzed with regard to the oxygenate
compound content by gas chromatography coupled with a mass spectrometer (GC-MS) and evaluated by sensory analysis, and also
with regard to the aldehyde content. As one could expect, there is a strong relationship between oil quality, as revealed
by the sensory analysis, and chemical composition, as determined by GC-MS. The concentration factor and process yield, as
expressed by “fold,” together with the analysis results show that it is possible to obtain high quality concentrates simply
by manipulating the operating variables in the vacuum fractionation process. 相似文献
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Deven A Jogdeo Keshvan Niranjan Vishwas G Pangarkar 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2000,75(8):673-680
This paper describes the results of a study on use of the adsorption–regeneration technique for recovery of dissolved allyl isothiocyanate(AITC) which is present in significant quantities in steam distillation condensate of mustard essential oil (MEO). Equilibrium and dynamic breakthrough studies were carried out. The adsorbents used were polymeric adsorbents: Amberlite XAD‐2, Amberlite XAD‐4, Amberlite XAD‐7, NPA‐1 and NPA‐2. The results obtained indicate that Amberlite XAD‐4 is the best amongst these various adsorbents. AITC recoveries in excess of 95% were obtained, indicating the feasibility of this approach. Further, since no chemical reactions are involved the recovered AITC retains its ‘natural’ origin. © 2000 Society of Chemical Industry 相似文献
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根据高温费托合成反应水的组成特点,采用连续精馏塔对反应水进行初分,以脱除大部分水和有机酸,同时,将非酸类含氧有机物提浓,利于后续化学品分离。首先采用NRTL热力学方法对流程进行了模拟,考察了塔板数、进料位置、回流比等工艺条件对分离结果的影响,得到了最优操作条件,然后采用实验室小型精馏塔对高温费托合成中试副产反应水进行了实验验证。结果表明:塔顶有机物质量分数可提高到75%以上,有机酸质量分数为0;塔釜采出物中非酸有机物质量分数小于0.01%,模拟最优条件为塔板数35块、进料位置为第15块,回流比为4。实验值与模拟值吻合良好。 相似文献