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1.
萃取八角茴香精油的研究   总被引:4,自引:0,他引:4  
用超临界CO2萃取八角茴香精油。采用4因素4水平的正交试验,得出超临界CO2萃取八角茴香精油的最佳工艺条件为:压力16 MPa、温度35℃、时间2 h、CO2流量30 L/h。在此条件下,八角茴香萃取物得率为10.5%。采用水蒸气蒸馏提取精油,得率为7.5%。对两种不同提取方法得到的精油的品质和得率进行了比较。超临界CO2萃取方法得到的八角茴香精油产品得率比水蒸气法高出40%,并且香气更全面。  相似文献   

2.
萃取山苍子核仁油的工艺研究   总被引:2,自引:0,他引:2  
研究了用超临界CO2流体萃取山苍子核仁油的萃取工艺,探讨了各种影响因素对山苍子核仁油萃取率的影响,通过正交试验确定了超临界萃取的最佳工艺为:萃取温度45℃、萃取压力25 MPa、CO2流量220 L/h、萃取时间80 min。在此条件下,山苍子核仁油萃取率84.5%。研究证明了加入溶剂和剥壳均可提高山苍子核仁油的萃取率。  相似文献   

3.
采用GC-MS法对超临界CO2萃取天然除虫菊的化学成分进行了分析,用归一化法测定了各组分的相对百分含量。结果共分离出53个组分,鉴定了31个成分,已鉴定的化合物组分占总馏出组分的58.5%。结果表明超临界CO2萃取的天然除虫菊的主要成分为除虫菊酯类以及烷烃类、烯醇、烯酸、甾醇、脂肪酸,其中除虫菊酯的相对含量为50.70%。  相似文献   

4.
提取野菊花中的精油   总被引:5,自引:0,他引:5  
采用超临界CO2萃取技术,研究了从野菊花中提取精油的工艺并鉴定其主要化学成分。对影响超临界CO2萃取精油的各因素进行了单因素试验研究,得到较适宜的萃取工艺条件,萃取温度 35℃、分离温度 30℃、萃取时间 90 min、萃取压力 25 MPa、CO2流量为 30 kg/h。在上述萃取工艺条件下,精油得率 9.65%。经GC-MS分析鉴定了野菊花精油成分43个,主要是萜类及其含氧衍生物、烷烃类化合物和酯类化合物等。  相似文献   

5.
提取花生壳中多酚类物质   总被引:9,自引:0,他引:9  
采用超临界CO2萃取技术,研究了从花生壳中提取多酚类物质的工艺。对影响超临界CO2萃取多酚的各种因素进行了单因素试验研究,得到较适宜的萃取工艺条件为:萃取温度60℃、萃取时间2 h、萃取压力20 MPa、夹带剂用80%乙醇(体积分数,其用量为每克原料4 mL)。在上述较适宜的萃取工艺条件下,多酚类物质得率为6.19%。  相似文献   

6.
下Pd/C催化剂催化 松香加氢反应的研究   总被引:2,自引:0,他引:2  
在超临界CO2条件下采用Pd/C催化剂进行催化松香加氢反应的研究。超临界CO2条件与常规条件下反应产物相比较,产品中枞酸、去氢枞酸含量都较常规条件下的氢化松香产品低。详细考察了反应温度、反应时间、催化剂用量、催化剂重复使用对反应的影响。结果表明Pd/C催化剂中Pd的流失是造成催化剂失活的主要原因。  相似文献   

7.
赵传文  陈晓平  赵长遂 《化工学报》2009,60(7):1800-1805
The structure identification and carbonation characteristics of several potassium-based supported sorbents for CO2 capture were investigated with TGA,XRD,XRF,SEM and N2 adsorption method.Potassium-based sorbents were prepared by impregnation with potassium carbonate on supports,such as cocoanut activated charcoal(AC1),coal active carbon(AC2),silica gel(SG)and diatomite(DT)using the iso-volume impregnation method.The results showed that the K2CO3 loading amounts of AC1,AC2,SG and DT were 24.1%,22.5%,21.7% and 19.1% respectively.The surface area and pore volume of K2CO3/AC1 and K2CO3/AC2 were larger than others.In contrast,those of K2CO3/DT were small.For K2CO3/SG,pore volume was large but surface area was small.K2CO3/AC1 and K2CO3/AC2 showed excellent carbonation capacity.However,the carbonation capacities of K2CO3/SG and K2CO3/DT were low.The difference in carbonation capacity of those sorbents were attributed to the difference in pore structure,leading to different supported sorbents.  相似文献   

8.
负载型K2CO3/Al2O3二氧化碳吸收剂的碳酸化反应特性   总被引:2,自引:0,他引:2  
赵传文  陈晓平  赵长遂 《化工学报》2009,60(4):1022-1027
The carbonation characteristics of K2CO3/Al2O3 supported sorbent for CO2 capture was investigated with thermogravimetric apparatus(TGA),X-ray diffraction(XRD),scanning electron microscopy analysis(SEM)and N2 adsorption.The results showed that the carbonation rate of K2CO3 before being loaded on Al2O3 was slow.However,the K2CO3/Al2O3 upported sorbent showed excellent carbonation performance.The difference in carbonation behavior between K2CO3 nd K2CO3/Al2O3 supported sorbent was analyzed from the microscopic view.The analytical reagent K2CO3 sample was of monoclinic crystal structure and could react quickly with H2O in the experimental carbonation environment to produce K2CO3•1.5H2O,which was unfavorable to carbonation reaction.When K2CO3was loaded on Al2O3,the surface area and porosity of the sorbent was improved greatly.So the carbonation properties of the K2CO3/Al2O3 supported sorbent was also improved.  相似文献   

9.
以银杏叶为材料,研究了超临界CO2萃取过程中银杏内酯A、B、C在不同时间段内即时质量分数与总获得量的动态变化。采用液相色谱与蒸发光检测器联用检测银杏内酯。结果表明,银杏萃取物的质量随萃取时间的延长而越来越少,前40 min萃取物质量占总量的55.9%。银杏内酯质量分数随萃取时间的延长先增加后减少。银杏内酯A的即时质量分数最高值出现在60~80 min时间段内,为0.403%,银杏内酯B、C即时质量分数最高值在40~60 min时间段内,分别为0.289%、0.246%。银杏内酯A、B、C总获得量随萃取时间的延长而减少,0~20 min时间段内是最高的,分别占整个180 min获得量的33.6%、33.3%、35.4%。  相似文献   

10.
本文介绍了工业上CO2的主要来源及应用,以及工业上分离、回收CO2的常用方法。同时介绍了活性炭在变压吸附分离气体领域的应用,以及变压吸附过程中吸附剂再生的常用方法。详细综述了活性炭的孔结构、表面化学结构等因素对CO2的吸附及解吸性能影响的研究进展。  相似文献   

11.
在Moldflow分析软件的基础上,对显示器后壳进行仿真研究,以翘曲变形量为质量指标,结合控制变量法进行单因素变动实验,保持注射工艺参数不变,研究显示器后壳底座连接口对制品翘曲变形的影响。对数据进行图表分析,结果表明显示器后壳尺寸定位68.58 cm(27英寸)时,底座连接口选用圆形,连接口位置距离底边26 mm,尺寸为直径21 mm的时候模具翘曲表现更好。  相似文献   

12.
The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion.  相似文献   

13.
In cement industry, a great energy consumption has been observed during grinding of clinker. To reduce this consumption, some waste products have been used as grinding aids.In this investigation, the effects of sunflower oil (SO), oleic acid (OA), stearic acid (SA), myristic acid (MA) and lauric acid (LA) on the fineness and strength of the cement have been examined. These aids were added into clinker in certain ratios based on the cement clinker weight and the grinding has been done for a definite time at the same condition.All of the fatty acids used increased the fineness as compared with the cement without the grinding additives. SO and OA decreased the strength significantly, LA decreased it to a lesser extent and SA increased it definitely according to the common cement. But MA did not alter the strength of the cement as much as SA. In addition, the covering of the balls influences the grinding of cement clinker unfavourably.  相似文献   

14.
浅谈设备的性能与操作对胎面压出质量的影响   总被引:1,自引:0,他引:1  
简要介绍了胎面压出的工作原理及工艺过程,对设备的配置及操作对胎面压出质量的影响进行了分析,并对压出过程中常见的质量缺陷、造成的原因以及解决措施提出了自己的见解。  相似文献   

15.
由反映火炸药及其制品的危险性能和用于对它们的生产、储运系统进行安全评价数学模型出发,探讨了如何建立一个全面、实用的火炸药安全评估数据库。通过对此数据库内容、数据表示方法、数据搜索方法以及建立步骤的讨论,明确了该数据库的使用对象和主要功能。  相似文献   

16.
17.
郭伟  郭晓镭  吴跃  黄斌  龚欣 《煤化工》2011,39(5):9-11,14
针对GSP气化装置煤粉气力输送在试车阶段出现的煤粉锁斗下料不畅、发料罐输送性能不佳等问题,从原料煤性质和工业装置的改进方面出发,通过煤粉的流动性参数的测量与研究,分析出现上述工程问题可能的内在原因,并提出工业装置改进方法,为保证GSP煤粉气力输送工业装置的正常运行提供解决办法。  相似文献   

18.
Polyurethaneureas (PUU), which were synthesized from 4,4′-diphenylmethane diisocyanate (MDI), poly(ethylene glycol) (PEG), and 3,5-diaminobanzoic acid (DABA), were used as polyelectrolytes in this study. Differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were used to monitor the effect of the various kinds of PEG on the changes in morphology of PUU electrolytes corresponding to the concentration of lithium perchlorate (LiClO4) dopants. The results of DSC and FT-IR indicate the Li+ ions coordinate with the soft and hard segments. Additionally, the crystallinity of the PEG soft segment and the ordered hydrogen-bonded urea carbonyl groups decreased with increasing salt concentration. Impedance spectroscopy (IS) measurements show that the PUU electrolyte with the high phase separation degree has the high ionic conductivity. The hard-segment Tg and the soft-segment Tm influence the conductivity behavior of polyelectrolytes with increasing measurement temperature.  相似文献   

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